Aspects of Vascular Tests

• Alnaeb ME, Crabtree VP et al: Prospective assessment of lower-extremity peripheral arterial disease in diabetic patients using a novel automated optical device. Angiology 58:579-85, 2007. A new optical device based on the photoplethysmograph (PPG) method and an innovative algorithm for the assessment of lower-extremity peripheral arterial disease was investigated prospectively in patients with type II diabetes. This new functional PPG (fPPG) technique uses a cuffless functional test to assess diabetic peripheral arterial disease without operator dependency and the incompressible arteries, issues associated with ankle brachial pressure index (ABPI) measurement. Diabetic patients (n = 24; 47 legs; age, 70 +/- 3 years) were recruited from the vascular clinic, and controls (n = 15; 30 legs; age, 66 +/- 5 years) were recruited from the orthopedic outpatient clinic. All underwent resting ABPI, fPPG, and duplex angiography (DA) as "gold standard." fPPG requires the placement of an optical probe on the toe for acquisition of pulsatile arterial perfusion for a period of 30 seconds with the leg in supine and raised at 45 degrees positions. The data were analyzed, and indices were generated by an automated computer system. In those with diabetes, fPPG correlated significantly with DA (r = -.68, P < .01) and ABPI (r = -.65, P < .01). We also found a significant correlation between ABPI and DA (r = .81, P < .01). The analysis of the receiver operator curve showed that optimum sensitivity and specificity for ABPI and fPPG were 80% and 93% and 83% and 71%, respectively, against DA. This method uses changes in pulsatile arterial blood volume using a simple cuffless functional test. The fPPG investigation period was much shorter (5 minutes) with independence of operator skills, whereas ABPI took longer (10-15 minutes) and required operator experience. Although the fPPG results are promising, further improvement (eg, by incorporation of functional skin color and temperature changes) is required to improve the sensitivity and specificity of the system. Comments: The PPG sensor must be applied to the skin of the toe by some means. Some apparatuses come with clips that hold the sensor firmly against the toe blanching the skin beneath to sensor to some degree. Again the clips provided may differ in how hard they squeeze the toe. Other apparatuses come with transparent tape with clear adhesive material on both sides; usage of this tape to hold the sensor to the skin avoids pressure on the toe. The authors do not tell us what they did in this regard. This study could be compared to the "pole test". See Påhlsson et al below.

• Ameli1 FM, Knackstedt J, Provan JL, St. Louis EL: The effect of femoral arteriography on the incidence of groin contamination and postoperative infections. Annals of Vascular Surgery 4: 328-332, 1990. Abstract A prospective study is presented on the effects of preoperative femoral arteriography on bacterial contamination and postoperative wound complications from groin incisions. Forty-four femoral reconstructive procedures (88 groin incisions) for aortoiliac disease were performed. Positive cultures occurred in 43.2% of patients and in 30.7% of the 88 incisions. There was no correlation found between the site of arteriography and positive cultures (Spearman correlation coefficient, p > .10). No correlation was found between the presence of hematoma due to arteriography and subsequent positive groin culture (Spearman correlation coefficient, p > .10). A higher incidence of positive cultures did occur for patients who had a difficult arteriographic procedure (Fisher's exact test, p=.020) or whose reconstructive procedure was greater than four hours (Fischer's exact test, p=.047). Seven patients had postoperative groin wound complications (15.9%), including three lymph leaks (6.8%) and four confirmed or suspected infections (9%). There were no graft infections. No correlation was found between the site of arteriography and the site of wound complication (Spearman correlation coefficient, p > .10). Neither positive culture results nor difficult arteriography nor presence of hematoma were accurate predictors of postoperative wound complications. We conclude that transfemoral arteriography does not increase the risk of complications of arterial reconstruction involving a femoral anastomosis.Comments: Positive cultures occurred in 43.2% of patients and in 30.7% of the 88 incisions.A higher incidence of positive cultures did occur for patients who had a difficult arteriographic procedure (Fisher's exact test, p=.020) or whose reconstructive procedure was greater than four hours (Fischer's exact test, p=.047). Seven patients had postoperative groin wound complications (15.9%), including three lymph leaks (6.8%) and four confirmed or suspected infections (9%). Sounds like there were significant problems overall. Still the authors point out that the problems were not easily correlated with the arteriogram procedure.

• Andreozzi GM, Riggio F, Buttò G, Barresi M, Leone A, Pennisi G, Martini R and Signorelli SS: Transcutaneous PCO2 Level as an index of tissue resistance to ischemia. Angiology 46:1097-1102, 1995. The authors performed a retrospective study on a data base of 525 patients with peripheral arterial disease, to analyze the pathophysiologic meaning of resting transcutaneous pressure of carbon dioxide (PCO2) and of CO2 production during three minutes of local ischemia. The resting and postischemic PCO2 and its maximum increase related to rest (PCO2 production) were measured with Kontron 7640 equipment. A Clarke electrode was placed on the metatarsal skin and recordings made at rest and during and after 3 minutes of local ischemia induced by a cuff inflated above ankle local systolic pressure. The resting TcPCO2 and postischemic TcPCO2 respectively were related to Fontaine's functional stages as follows: Stage 1 (exceptional claudication in patients with isolated arterial stenosis of the lower limb) 37.83±2.25 and 41.08±8.54; Stage 2A (stable claudication with maximum claudication distance over 200 meters) 38.32±4.07 and 42.98±6.14; Stage 2B (stable claudication with maximum claudication distance under 200 meters) 40.46±5.26 and 45.70±7.29; Stage 3 (those with rest pain) 40.77±6.15 and 47.11±9.56; and Stage 4 (those with rest pain and trophic skin damage) 42.37±6.43 and 51.02±8.10. Except in the first stage where there were only 12 patients, the rises were significant (P<0.0001). The authors felt that the TcPCO2 could be an expression of the tissue metabolic performance and, overall, of the tissue's resistance to ischemia, whereas TcPO2 was an expression of tissue perfusion. Comments: The authors have nicely provided us with basal and postischemic TcPCO2 levels related to a functional ischemic class of patients. The Fontaine classification is not commonly used today but obviously makes sense and is here shown to be associated with progressive increases in PCO2. We find that both O2 and CO2 levels are commonly altered by the presence of cellulitis and agree with the authors that their value is greatly increased when interpreted along with techniques such as the laser Doppler.

• Apelqvist J, Castenfors J, Larsson J, Stenstrom A and Agardh C: Prognostic value of systolic ankle and toe blood pressure in outcome of diabetic foot ulcer. Diab Care 12:373-378, 1989. 314 patients. Toe pressure measured with stain-gauge technique and ankle likewise or with Doppler technique. 197 (62.7%) healed primarily. 77 (24.5%) had major amputations. 40 (12.7%) died before healing. No patient healed primarily with a systolic ankle pressure 40mm Hg. An upper limit above which amputation was not required could not be defined. Primary healing in 85% with a toe pressure > 45mm Hg., while 36% healed without amputation when the toe pressure was 45mm Hg. 4/31 with ankle BP less than 80 and 1/21 with toe BP less than or equal to 15 healed after amputation below the ankle. Need different criteria to predict primary healing vs that after minor amputations.

• Arveschoug AK, Revsbech P, Jens B-M: Sources of variation in the determination of distal blood pressure measured using the strain gauge technique. Clinical Physiology 18: 361–368, 1998. Using the determination of distal blood pressure (DBP) measured using the strain gauge technique as an example of a routine clinical physiological investigation involving many different observers (laboratory technicians), the present study was carried out to assess (1) the influence of the number of observers and the number of analyses made by each observer on the precision of a definitive value; and (2) the minimal difference between two determinations to detect a real change. A total of 45 patients participated in the study. They were all referred for DBP determination on suspicion of arterial peripheral vascular disease. In 30 of the patients, the DBP curves were read twice, with a 5-week interval, by 10 laboratory technicians. The results were analysed using the variance component model. The remaining 15 patients had their DBP determined twice on two different days with an interval of 1–3 days and the total day-to-day variation (SDdiff) of DBP was determined. The inter- and intraobserver variations were, respectively, 5·7 and 4·9 mmHg at ankle level and 3·5 and 2·7 mmHg at toe level. The index values as related to systolic pressure were somewhat lower. The mean day-to-day variation was 11 mmHg at ankle level and 10 mmHg at toe level, thereby giving a minimal significant difference between two DBP determinations of 22 mmHg at ankle and 20 mmHg at toe level. To decrease the value of SD (standard deviation) on a definitive determination of DBP and index values, it was slightly more effective if the value was based on two observers performing one independent DBP curve reading than if one observer made one or two DBP curve readings. The reduction in SDdiff was greatest at ankle level. The extent of the Sddiff decrease was greatest when two different observers made a single DBP reading each at both determinations compared with one different observer making two readings at each determination. Surprisingly, about half of the maximum reduction in the SDdiff was achieved just by increasing the number of observers from one to two. We have found variance component analyses to be a suitable method for determining intra- and interobserver variation when several different observers take part in a routine laboratory investigation. It may be applied to other laboratory methods such as renography, isotope cardiography and myocardial perfusion single-photon emission computerized tomography (SPECT) scintigraphy, in which the final result may be affected by individual judgement during processing.

• Ascher E, Hingorani A, Markevich N, Costa T, Kallakuri S, Khanimoy Y: Lower extremity revascularization without preoperative contrast arteriography: experience with duplex ultrasound arterial mapping in 485 cases. Ann Vasc Surg 16(1):108-14, 2002. This study reviews our experience with duplex ultrasound arterial mapping (DUAM) for preoperative evaluation in 466 patients (262 men) who underwent 485 lower extremity revascularization procedures from January 1, 1998 to May 30, 2001. Preoperative imaging consisted of DUAM alone in 449 procedures and DUAM and contrast angiography (CA) in 36. An attempt to image from the distal aorta to the pedal arteries was made in all the patients. The selection of optimal inflow and outflow bypasses anastomotic sites was based on a schematic drawing following DUAM examination. Inflow disease was also assessed by intraoperative pressure gradient (IPG) between the distal anastomosis and radial arteries, and completion arteriography of the runoff vessels was obtained, which was correlated with the preoperative findings. Indications for surgery were severe claudication in 91 (19%) limbs, tissue loss in 197 (40%), rest pain in 113 (23%), acute ischemia in 46 (10%), popliteal aneurysm in 18 (4%), superficial femoral artery aneurysm in 1, abdominal aortic aneurysm with claudication in 1, and failing graft in 18 (4%). Age ranged from 30 to 97 years (mean 72 +/- 12 (SD) years) and risk factors such as diabetes, hypertension, use of tobacco, coronary artery disease, and end-stage renal disease were present in 45%, 45%, 44%, 44%, and 13% of the patients, respectively. One hundred twenty-one (25%) limbs had at least 1 previous ipsilateral revascularization. The mean DUAM time was 66 +/- 20 (SD) min (30-150 min). Additional preoperative imaging was deemed necessary in 36 cases due to extensive ulcers, edema, severe arterial wall calcification, and very poor runoff. The distal anastomosis was to the popliteal artery in 173 cases and to the tibial and pedal arteries in 255. Inflow procedures to the femoral arteries, embolectomy, thrombectomy, balloon angioplasty, and patch angioplasty accounted for the remaining 57 cases. Overall, 6-, 12-, and -24- month secondary patency rates were 86%, 80%, and 66%, respectively. This early experience shows that high-quality arterial ultrasonography performed by a highly skilled vascular technologist may represent an alternative to conventional arteriography for patients in need of lower extremity revascularization. Because of limitations inherent to the technique and very poor runoff observed on ultrasonographic examination, additional preoperative imaging procedure's are needed for certain patients.

• Asif A, Preston RA, Roth D: Radiocontrast-induced nephropathy. Am J The. 10: 137-47, 2003. Radiocontrast administration remains the third leading cause of hospital-acquired acute renal failure. Clinically, radiocontrast-induced nephropathy (RIN) is defined as a sudden decline in renal function after radiocontrast administration. Typically, the serum creatinine level begins to increase at 24 to 72 hours after the administration of contrast, peaks at 3 to 5 days, and requires another 3 to 5 days to return to baseline. RIN increases the incidence of life-threatening complications such as sepsis, bleeding, and respiratory failure and increases the cost of medical care by extending the hospital stay. The increased mortality associated with acute renal failure encountered in this scenario calls for a heightened awareness of the diagnosis and prevention of RIN. Whereas individuals with healthy renal function are not generally considered to be at particular risk for RIN, patients with preexisting renal insufficiency and diabetes mellitus are much more likely to experience acute renal failure after contrast administration. In the past, a variety of therapeutic interventions have been used to prevent or attenuate RIN, including saline hydration, diuretics, mannitol, calcium channel antagonists, theophylline, endothelin receptor antagonists, hemodialysis, and dopamine. More recently, studies demonstrate a positive impact of fenoldopam (dopamine-1 receptor, dopamine-1 agonist) and the antioxidant N-acetylcysteine in ameliorating RIN. This article discusses the pathophysiology, risk factors, and prevention of RIN.

• Augustine MJ, Eagleton KJ, Graham DH, Story SB et al: Accuracy of the ankle brachial pressure measurement by physical therapists and physical therapy students. Cardiopulmonary Physical Therapy Journal, Sep 2000. The technique for calculating the ABI has been described by many to include a minimum of 5 minutes rest in the supine position and systolic blood pressures are taken bilaterally in the brachial arteries and dorsalis pedis (or posterior tibial) arteries with the use of a Doppler ultrasound probe and a standard 12 cm arm cuff. For ankle determinations, the cuff is placed approximately 3 cm above the most proximal aspect of the medial malleolus. The highest arm and both leg pressures are used to calculate the ABIs for bilateral lower extremities by dividing the ankle pressure by arm systolic brachial pressure. The result is a ratio that can be compared to normalized data to determine the extent to which pathology is present or has progressed. Although there are variations in the techniques used to measure ABI, the accuracy of the measure has not been extensively researched when used by other health care professions. Ray et al8 attempted to test the interrater reliability of the ABI by comparing measures taken by qualified doctors with no formal training, qualified doctors with formal training, and experienced vascular technicians. These testers were divided into 2 groups. The first group consisted of 2 newly qualified doctors not trained in the use of Doppler ultrasonographic flow meters. The second group consisted of 2 other newly qualified doctors who underwent formal training in the Doppler ultrasound units as well as receiving continuous feedback during ABl measurements. Each doctor studied 38 limbs over a 6-week period. Their results were compared with those measurements taken by a registered vascular technician who also recorded ABI measurements on the same patients. Results showed that 29% of the measurements taken by the untrained doctors were incorrect by an ABI ratio of more than 0.15, as compared to those taken by the vascular technicians. In contrast, the doctors who received one formal training session and feedback from the vascular technician demonstrated that 15% of the measurements of an ABI ratio differed by greater than 0.15. The results of this study suggested that health professionals should undergo formal training before performing ABI measurements to increase their reliability.

• Brooks B, Dean R et al: TBI or not TBI: that is the question. Is it better to measure toe pressure than ankle pressure in diabetic patients? Diabet. Med 18:528-532, 2001. Abstract: Aims Measurement of ankle blood pressure is a simple method of assessing lower limb arterial blood supply. However, its use in diabetes has been questioned due to the presence of medial artery calcification. Measurement of toe blood pressure has been advocated as an alternative but it is technically more difficult. The aim of this study was to obtain information to guide clinicians as to when pressure measurements should be taken at the toe. Methods Ankle brachial index (ABI) and toe brachial index (TBI) were measured by Doppler ultrasound, or photoplethysmography on 174 subjects with diabetes and 53 control subjects. The Bland and Altman method, and the Cohen's method of measuring agreement between two tests were used to compare ABI with TBI. Results The mean differences between ABI and TBI in control and diabetic subjects are 0.40 T 0.13 and 0.37 T 0.15, respectively. Nearly all diabetic patients with an ABI < 1.3 have an ABI±TBI gradient falling within the normal range established from the non-diabetic cohort. In contrast, the majority of diabetic subjects with an ABI b 1.3 have ABI±TBI differences outside this range. When patients are categorized according to ABI and TBI, there is also good agreement between the tests when ABI is low or normal (84% and 78% agreement, respectively), but not when ABI is elevated. Conclusion In the majority of patients with diabetes, assessment of TBI conveys no advantage over ABI in determining perfusion pressure of the lower limbs. Only in those patients with overt calcification, which gives an ABI b 1.3, are toe pressure measurements superior. This guideline should simplify assessment and treatment of diabetic patients with disease of the lower limbs.

• Brown RF, Rice P, Bennett NJ: The use of laser Doppler imaging as an aid in clinical management decision making in the treatment of vesicant burns. Burns 24:692-8, 1998. Vesicants are a group of chemicals recognised, under the terms of the Chemical Weapons Convention, as potential chemical warfare agents whose prime effect on the skin is to cause burns and blistering. Experience of the clinical management of these injuries is not readily available and therefore an accurate assessment of the severity of the lesion and extent of tissue involvement is an important factor when determining the subsequent clinical management strategy for such lesions. This study was performed to assess the use of laser Doppler imaging (LDI) as a noninvasive means of assessing wound microvascular perfusion following challenge with the vesicant agents (sulphur mustard or lewisite) by comparing the images obtained with histopathological analysis of the lesion. Large white pigs were challenged with sulphur mustard (1.91 mg cm(-2)) or lewisite (0.3 mg.cm(-2)) vapour for periods of up to 6 h At intervals of between 1 h and 7 days following vesicant challenge, LDI images were acquired and samples for routine histopathology were taken. The results from this study suggest that LDI was: (i) a simple, reproducible and noninvasive means of assessing changes in tissue perfusion, and hence tissue viability, in developing and healing vesicant burns; (ii) the LDI images correlates well with histopathological assessment of the resulting lesions and the technique was sufficiently sensitive enough to discriminate between skin lesions of different aetiology. These attributes suggest that LDI would be a useful investigative tool that could aid clinical management decision making in the early treatment of vesicant agent-induced skin burns. Comments: Laser Doppler imaging is here seen to provide a means to assess the microcirculation under chemical burns. Likely the same is true for thermal burns. Now, the clinician may determine that an impairment in the microcirculation exists, what is he/she going to do about it? We have limited experience in booting such patients. Burns can be quiet painful. The pain can be reduced by booting the patient with pre-cooled air. The compressed air lines to the boot are commonly room temperature. They can be cooled by immersing them in ice water. The compressed air (60-90 PSI) expands into the boot bag (1-1.5 PSI) and cools further.

• Carpenter J: Magnetic resonance angiography in peripheral artery disease. Hosp Practice p79-97, Oct 15, 1992. Technique safer than contrast arteriography in which nearly 10% of patients will have minor to serious complications. Further, in up to 70% of patients, preoperative arteriography fails to identify suitable distal vessels for bypass. Here 51 patients with severe peripheral ischemia studied both with MRI and contrast arteriography. MRI identified 24% more patient vessel segments. In 18% of patients the vessels found by MRI were the only ones available for bypass. Contraindications for MRI: presence of a pacemaker, cerebral aneurysm clips or metal in the eye.

• Castellano IA, McNeill JG, Thorp NC, Dance DR, Raphael MJ.: Assessment of organ radiation doses and associated risk for digital bifemoral arteriography. Br J Radiol 68:502-7, 1995. An assessment has been made of the absorbed dose associated with femoral arteriography using a digital imaging system. A bilateral femoral arteriogram was performed on 17 patients, using a filmless 1024 matrix digital image acquisition system with a discrete stepping tube-stand and 40 cm image intensifier. A standardized protocol of manual patient/tube-stand positioning under fluoroscopic control and automatic stepping digital acquisition was followed. Skin entry doses were measured with a dose-area product meter for each stage of the procedure, and the total gonad dose was assessed with thermoluminescent dosimeters (TLDs). Published Monte Carlo simulations were supplemented with further calculations to evaluate organ doses from the dose-area products measured. Comparison with the TLD measurements indicated that this technique over-estimated organ doses by about 30%. A mean effective dose of 3.1 +/- 1.8 mSv was calculated for the procedure, with the greatest dose burden being imposed by fluoroscopy during catheter manipulation. The related radiation detriment is 0.018%, which is insignificant when compared with the overall mortality from peripheral vascular disease. Comments: Yes, people with PVD undergoing arteriography are at least physiologically older and have accordingly a diminished life expectancy. The radiation hazard may be more of a worry for younger patients perhaps undergoing the procedure after trauma.

• Castronuovo JJ Jr, Adera HM, Smiell JM, Price RM: Skin perfusion pressure measurement is valuable in the diagnosis of critical limb ischemia. J Vasc Surg 26(4):629-37, 1997. PURPOSE: Critical limb ischemia (CLI) is equated with a need for limb salvage. Arterial reconstruction and major amputation are the therapies ultimately available to such patients. We studied whether measurements of skin perfusion pressure (SPP) can be used to accurately identify those patients with CLI who require vascular reconstruction or major amputation and distinguish them from patients whose foot ulcer would heal with local wound care or minor amputation. METHODS: Fifty-three patients with a total of 61 limbs with a nonhealing foot ulcer (age range, 47 to 88 years; mean, 70.8 +/- 9.8 years; 33 men, 20 women) who were referred to the Vascular Laboratory at Morristown Memorial Hospital for evaluation of arterial insufficiency were studied in a prospective, double-blinded fashion. Patients were included in the study if informed consent was obtained, and patients were excluded if there was uncontrolled sepsis or if they required guillotine amputation. The size and site of the foot ulcer was recorded. If gangrene was present, the location and extent was also noted. The pulses were examined and recorded, and the ankle-brachial index was determined for each limb. Measurements of SPP were made at the proximal margin of the ulcer in viable tissue (not in the bed of the ulcer). SPP measurements were made independent of the vascular surgeon's evaluation of the limb and were not part of his clinical decision regarding management of the foot ulcer. The SPP measurements were compared (Fischer's exact test) with the clinical decision for therapy (group I, arterial reconstruction or major amputation; or group II, wound debridement, minor amputation, or both). SPP was also compared with the outcome (ulcer healed or failed to heal) of therapy in group II. From contingency tables we calculated the sensitivity, specificity, positive and negative predictive values (PPV, NPV), and the overall accuracy of SPP measurement as a diagnostic test for critical limb ischemia. RESULTS: There was no difference in the size or location of foot ulcers between groups I and II, nor was there a difference in ulcer size or location between limbs that healed and did not heal in group II. The prevalence of diabetes was similar in all groups and subgroups. The ABI was not predictive of the need for reconstruction or major amputation nor the outcome of local therapy. SPP measurements identified 31 of 32 limbs diagnosed as having CLI by clinical evaluation (i.e., group I, those limbs that required vascular reconstruction or major amputation). Of those patients who were clinically assessed as not having CLI (group II), SPP measurements diagnosed 12 of the 14 limbs that did not heal as having CLI (PPV, 75%) and 11 of 15 limbs that did heal as not having CLI (NPV, 85%). The sensitivity of SPP less than 30 mm Hg as a diagnostic test of CLI was 85%, and the specificity was 73%. The overall diagnostic accuracy of SPP less than 30 mm Hg as a diagnostic test of critical limb ischemia was 79.3% (p < 0.002, Fischer's exact test). CONCLUSIONS: We conclude that SPP measurement is an objective, noninvasive method that can be used to diagnose critical limb ischemia with approximately 80% accuracy.

• Catalano M et al: Microcirculation and hemorheology in NIDDM patients. Angiology 41:1053-1057,1990. 10 patients: 4 had retinal fluorangiographic changes and all ten had capillaroscopic alterations at the bulbar conjunctiva (microaneurysms, erythrocyte aggregates) and nail folds (tortuosity, dilatations and microaneurysms more severe in toes than fingers). Abnormalities independent of hemorheologic values.

• Conlon KC, Sclafani L, DiResta GR, Brennan MF: Comparison of transcutaneous oximetry and laser Doppler flowmetry as noninvasive predictors of wound healing after excision of extremity soft-tissue sarcomas. Surgery 115(3):335-40, 1994. BACKGROUND. We wished to determine whether transcutaneous oximetry or laser Doppler flowmetry (LDF) could identify patients at risk for wound failure after conservative, limb-sparing surgery for extremity sarcomas. METHODS. Studies were performed on postoperative days (PODs) 1, 4/5, 7, and 9. Measurements of transcutaneous oxygen pressure (tcPO2) were taken at breathing room air (BL) and 100% oxygen (rate tcPO2). LDF measurements were taken at multiple sites along the wound, and a perfusion index was calculated. RESULTS. Twenty-four patients were studied. Four (17%) had nonhealing wounds. There was no difference in tcPO2 (BL) values between healed and nonhealing wounds. Measurement of rate tcPO2 on POD 1 was significantly lower in the nonhealing wounds than in those with normal healing (28.5 +/- 12.1 mm Hg vs 14.3 +/- 16.2 mm Hg, mean +/- SD, p = 0.03). Rate tcPO2 values increased significantly in healing wounds from POD 1 to PODs 7 and 9 (p = 0.006, p = 0.009). This increase was absent in nonhealing wounds. A clear separation was noted in rate tcPO2 values between groups, with a minimum rate tcPO2 value recorded in a healed wound of 9 mm Hg/min, compared with the maximum value in a nonhealing wound of 7 mm Hg/min. The LDF perfusion index failed to predict wound healing at any of the measured time points. CONCLUSIONS. This study showed that measurement of tcPO2 during oxygen inhalation can accurately predict wound healing in patients after excision of an extremity sarcoma. Comments: Rate TcPO2 appears to provide an important physiological measurement in predicting wound healing in these patients.

• de Graaff JC, Ubbink DT, Legemate DA, de Haan RJ, Jacobs MJ: Interobserver and intraobserver reproducibility of peripheral blood and oxygen pressure measurements in the assessment of lower extremity arterial disease. J Vasc Surg 33: 1033-40, 2001. INTRODUCTION: Peripheral blood pressure measurements play a prominent role in the diagnosis and follow-up of patients with peripheral vascular diseases. Toe pressure of the hallux (TP1) and second toe (TP2) and transcutaneous oxygen pressure (TCPO2) measurements are becoming more important. The ankle/brachial pressure index (ABPI) is known to be a reliable parameter, but the toe pressure and TCPO2 are evaluated less thoroughly. Therefore, we evaluated the reproducibility of TP1, TP2, TCPO2, ABPI, ankle pressure (AP), and brachial pressure (BP). PATIENTS AND METHODS: In 54 patients with various stages of peripheral vascular disease, the intraobserver and interobserver reproducibility of BP, AP, ABPI, TP1, TP2, and TCPO2 was investigated by calculating the repeatability coefficient (RC) and the intraclass correlation coefficient (ICC) and by using Bland-Altman plots. RESULTS: The intraobserver and interobserver reproducibility at 1 day and after 1 week of BP, AP, ABPI, and TP1 was substantial and comparable (ICC range, 0.80-0.99), except for the BP after 1 week. The TP2 and TCPO2 were less reproducible (ICC range, 0.62-0.98). The interobserver RC of BP was 31 mm Hg; of AP, 44 mm Hg; of ABPI, 27%; of TP1, 41 mm Hg; of TP2, 67 mm Hg; and of TCPO2; 30 mm Hg. The difference plot showed that the observer variability was equally distributed across the range of pressure in all measurements. CONCLUSION: The BP, AP, ABPI, and TP1 have a substantial intraobserver and interobserver reproducibility, whereas TP2 and TCPO2 show worse reproducibility. Especially when low values (or values around a cutoff value) are measured, the RC should be taken into account, and repetition of the measurement is advocated.

• de Graaff JC, Ubbink DT, Legemate DA, Tijssen JG, Jacobs MJ: Evaluation of toe pressure and transcutaneous oxygen measurements in management of chronic critical leg ischemia: a diagnostic randomized clinical trial. J Vasc Surg 38:528-34, 2003. Abstract: OBJECTIVE: The definition of critical limb ischemia (CLI) requiring vascular intervention is still under debate. The clinical eye of the physician and ankle blood pressure measurements used so far may fall short in appreciation of the severity of disease, which makes decision-making for a vascular intervention subjective. In previous studies two simple functional tests, ie, transcutaneous oxygen pressure (tcPo(2)) and toe blood pressure (TP) measurements, provided reliable information about the need for vascular intervention. Therefore we evaluated the diagnostic value of tcPo(2) and TP in management of clinically suspected critical leg ischemia. Study design This was a diagnostic randomized controlled clinical trial. Subjects were ambulatory and hospitalized patients in a referral university hospital. METHODS: Ninety-six patients (128 legs) with clinically suspected critical limb ischemia were referred to the vascular laboratory for routine investigation. Two diagnostic management strategies were compared: conventional strategy, ie, clinical judgment and ankle pressure determined the diagnostic and therapeutic approach, and a new strategy in which tcPo(2) and TP determined the diagnostic and therapeutic approach. Main outcome measures included clinical outcome, defined as pain relief, wound healing, and limb survival. RESULTS: At 18-month follow-up, 26 of 62 legs treated with the conventional approach and 28 of 66 legs treated with the new approach were treated conservatively. The new method did not score significantly different from the conventional method insofar as clinical outcome: pain score, 50 versus 48; number of amputations, 8 versus 10; and number of deaths, 11 versus 8 deaths, respectively. CONCLUSION: Two simple objective diagnostic tests, TP and tcPo(2), did not improve clinical outcome when incorporated into routine management of suspected critical limb ischemia. Nevertheless, these techniques might still be helpful for physicians less experienced with treating critical limb ischemia and who are in doubt regarding the need for vascular intervention.

• D'Souza V, Formanek A, Castaneda W, Knight L, Amplatz K: Peripheral angiograph enhancement by long leg pneumatic boots. Radiology 120(1):209-12, 1976. Abstract: In patients with arterial occlusive disease it is virtually impossible to predict the speed of blood flow due to the presence of stenoses, occlusions, and collaterals. Repeated exposures and injections can be avoided by use of pneumatic boots which increase peripheral blood flow by reactive hyperemia, are well tolerated by patients, and decrease the pain associated with the injection of contrast material. Comments: One is reminded of the distraught urologist who lost the opportunity to cystoscope his patient to remove a stone when the patient signed out of the hospital after the intern ordered a hot bath; a hot bath may relax the ureters and allow stones to pass spontaneously. Here the radiologists note improved visualization of leg vasculature after pumping. Pumping with the Circulator Long-Boot decreases stasis and may lyse soft recent clot... both effects improving visualization of the leg arteries to help plan vascular reconstruction... and, by improving runoff, pumping may improve the chances for success of any bypass. If the patient does too well with the pumping, however, the surgeon may find that the patient refuses surgery.

• Dodd HJ, Gaylarde PM and Sarkany I: Skin oxygen tension in venous insufficiency of the lower leg. J Royal Soc Med 78:373-376, 1985. In recumbent position venous patients had higher PO2 than controls. Due to reflex vasoconstriction PO2 falls on quiet standing in patients and controls. PO2 rises with exercise in controls but not in patients. Failure of PO2 to rise with exercise is the factor promoting leg ulcers.

• Feigelson HS, Criqui MH, Fronek A, Langer RD and Molgaard CA: Screening for peripheral arterial disease: the sensitivity, specificity, and predictive value of noninvasive tests in a defined population. Am J Epidemiol 140:526-34, 1994. Authors' abstract: Large vessel peripheral arterial disease(LV-PAD) is a common condition that causes significant morbidity and disability. The authors evaluated the individual components of a comprehensive noninvasive vascular examination to identify the most sensitive and specific measurements for diagnosing LV-PAD. This cohort, initially screened between 1979 and 1981 in Rancho Bernardo, California, included 421 normal subjects and 63 subjects with LV-PAD. Segmental blood pressure ratios and flow velocities by Doppler ultrasound were used to define cases of LV-PAD. The sensitivity, specificity, positive predictive value, and negative predictive value of each individual component of the diagnostic algorithm were determined. Overall, measurements of posterior tibial flow showed the highest sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy. In addition, an absent or non-recordable posterior tibial peak forward flow , occurring in 96% of all limbs with isolated posterior tibial disease, or an ankle ratio ( 0.8 considered in parallel yielded a test with a sensitivity of 89%, specificity 99%, positive predictive value 90%, a negative predictive value 99%, and an overall accuracy of 98%. These results indicate that the vast majority of LV-PAD cases can be detected with a single measurement using a handheld Doppler flowmeter employed at the ankle.

• Fife CE, Buyukcakir C, Otto GH, Sheffield PJ, Warriner RA, Love TL, Mader J: The predictive value of transcutaneous oxygen tension measurement in diabetic lower extremity ulcers treated with hyperbaric oxygen therapy: a retrospective analysis of 1,144 patients. Wound Repair Regen 10:198-207, 2002. The objective of this retrospective analysis was to determine the reliability of transcutaneous oxygen tension measurement (TcPO2) in predicting outcomes of diabetics who underwent hyperbaric oxygen therapy for lower extremity wounds. Six hyperbaric facilities provided TcPO2 data under several possible conditions: breathing air, breathing oxygen at sea level, and breathing oxygen in the chamber. Overall, 75.6% of the patients improved after hyperbaric oxygen therapy. Baseline sea-level air TcPO2 identified the degree of tissue hypoxia but had little statistical relationship with outcome prediction because some patients healed after hyperbaric oxygen therapy despite very low prehyperbaric TcPO2 values. Breathing oxygen at sea level was unreliable for predicting failure, but 68% reliable for predicting success after hyperbaric oxygen therapy. TcPO2 measured in chamber provides the best single discriminator between success and failure of hyperbaric oxygen therapy using a cutoff score of 200 mmHg. The reliability of in-chamber TcPO2 as an isolated measure was 74% with a positive predictive value of 58%. Better results can be obtained by combining information about sea-level air and in-chamber oxygen. A sea-level air TcPO2 < 15 mmHg combined with an in-chamber TcPO2 < 400 mmHg predicts failure of hyperbaric oxygen therapy with a reliability of 75.8% and a positive predictive value of 73.3%.

• Fife CE, Smart DR, Sheffield PJ, Hopf HW, Hawkins G, Clarke D: Transcutaneous oximetry in clinical practice: consensus statements from an expert panel based on evidence. Undersea Hyperb Med 36:43-53, 2009. Transcutaneous oximetry (PtcO2) is finding increasing application as a diagnostic tool to assess the peri-wound oxygen tension of wounds, ulcers, and skin flaps. It must be remembered that PtcO2 measures the oxygen partial pressure in adjacent areas of a wound and does not represent the actual partial pressure of oxygen within the wound, which is extremely difficult to perform. To provide clinical practice guidelines, an expert panel was convened with participants drawn from the transcutaneous oximetry workshop held on June 13, 2007, in Maui, Hawaii. Important consensus statements were (a) tissue hypoxia is defined as a PtcO2 <40 mm Hg; (b) in patients without vascular disease, PtcO2 values on the extremity increase to a value >100 mm Hg when breathing 100% oxygen under normobaric pressures; (c) patients with critical limb ischemia (ankle systolic pressure of < or =50 mm Hg or toe systolic pressure of < or =30 mm Hg) breathing air will usually have a PtcO2 <30 mm Hg; (d) low PtcO2 values obtained while breathing normobaric air can be caused by a diffusion barrier; (e) a PtcO2 <40 mm Hg obtained while breathing normobaric air is associated with a reduced likelihood of amputation healing; (f) if the baseline PtcO2 increases <10 mm Hg while breathing 100% normobaric oxygen, this is at least 68% accurate in predicting failure of healing post-amputation; (g) an increase in PtcO2 to >40 mm Hg during normobaric air breathing after revascularization is usually associated with subsequent healing, although the increase in PtcO2 may be delayed; (h) PtcO2 obtained while breathing normobaric air can assist in identifying which patients will not heal spontaneously.

• Fitzgerald DE and Carr J: Peripheral arterial disease: assessment by arteriography and alternative noninvasive measurements. Am J Roetgenol 128:385, 1977. Noninvasive studies 99.3% accurate in predicting arteriogram. 40% of 3000 patients with arteriograms showed inoperable disease.

• Foo JY: Bilateral transit time assessment of upper and lower limbs as a surrogate ankle brachial index marker. Angiology 59:283-9. 2008. Ankle brachial index is useful in monitoring the pathogenesis of peripheral arterial occlusive diseases. Sphygmomanometer is the standard instrument widely used but frequent prolonged monitoring can be less comfortable for patients. Pulse transit time is known to be inversely correlated with blood pressure and a ratio-based pulse transit time measurement has been proposed as a surrogate ankle brachial index marker. In this study, 17 normotensive adults (9 men; aged 25.4 +/- 3.9 years) were recruited. Two postural change test activities were performed to induce changes in the stiffness of the arterial wall of the moved periphery. Results showed that only readings from the limbs that adopted a new posture registered significant blood pressure and pulse transit time changes (P < .05). Furthermore, there was significant correlation between the ankle brachial index and pulse transit time ratio measure for both test activities (R(2) > or = 0.704). The findings herein suggest that pulse transit time ratio is a surrogate and accommodating ankle brachial index marker.

• Fowkes FG, Housley E, Macintyre CC, Prescott RJ, Buckley CV: Variability of ankle and brachial systolic pressures in the measurement of atherosclerotic peripheral arterial disease. J Epidem and Community Health 42: 128-133, 1988. The aim of this study was to determine the variability of measurements of ankle and brachial systolic pressures and ankle brachial ratios in order to assess their suitability for use in epidemiological studies of arterial disease in the lower limbs. Thirty-six subjects had repeat measurements taken by four observers on two separate days using a Doppler probe and random zero sphygmomanometer. The variability in the measurement of ankle systolic pressure was comparable to that for brachial systolic pressure. The 95% confidence limits of one measurement of the ankle brachial ratio was estimated to be +/- 16%, reducing to +/- 10% for the mean of four measurements taken by two observers on two days. Analysis of variance indicated that the variability in the measurement of ankle brachial ratios attributable to observers, days, timing of measurements on the same day, and repeat measurements was considerably less than the "biological" variability between subjects and between legs. These results suggest that repeatability of the ankle brachial ratio is such that a single measurement is suitable for most epidemiological studies of atherosclerotic peripheral arterial disease. Comments: Yes, a single determination may be sufficient for disease classification in epidemiology studies but not sufficient to document post-treatment changes especially if they are small.

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• Gannon MX, Goldman M, Simms MH and Hardman J: Transcutaneous oxygen tension monitoring during vascular reconstruction. J Cardiovasc Surg 27:450-453, 1986. Regional profusion index (RPI) = foot TcPO2/chest TcPO2. RPI was equivalent to TcPO2 as a measure of ischemia. Successful bypass led to an on table rise of RPI which rose insignificantly further post-operatively.

• Gardner AW and Montgomery PS: Comparison of three blood pressure methods used for determining ankle/brachial index in patients with intermittent claudication. Angiology 49: 723-728, 1998. The authors determined the ankle blood pressure with a Doppler while they obtained the brachial blood pressure in randomized order by three methods: the Doppler, auscultatory and oscillometric. The latter measurements differed little (Doppler 128.5+/-18.4 mmHg, auscultatory 128.4+/-17.4 mmHg and oscillometric 128.2+/-17.1 mmHg). They showed that the ABI is little affected by the method chosen to determine the brachial pressure. Comments: A paper easy to understand. A brachial pressure taken carefully may be accurate taken by any of the methods used. It is not uncommon for the vascular technician to measure the ankle pressure, however, and forget to take the arm pressure until later when the patient has risen from the supine position and the Doppler has been stored away. These authors are not telling us that a sitting and supine blood pressure determination may not differ significantly, especially in diabetics with neuropathy.

• Griffiths GD amd Wieman TJ: The influence of renal function on diabetic foot ulceration. Arch Surg 125:1567-1569, 1990. Summary: A retrospective chart analysis. Creatinine clearance, peripheral neuropathy and PVD all independently associated with foot ulcers. Renal function had no bearing on severity of foot lesions or capacity to heal. Comment: presence of neuropathy assessed "clinically" and by electrophysiologic testing... here neuropathy reported to be "present" in 94% of patients requiring partial amputation while PVD present in 24%... point no quantitation of neuropathy or PVD in this study ... Three patients on dialysis here not further described ... No patients with transplants described and immunotherapy a potential risk factor for infection.

• Hiatt WR, Hoag S, Hamman RF: Effect of Diagnostic Criteria on the Prevalence of Peripheral Arterial Disease, The San Luis Valley Diabetes Study. Circulation 91:1472-1479, 1995. Background The ankle/brachial systolic blood pressure index (ABI), a noninvasive measure of peripheral arterial disease (PAD), is widely used in epidemiological studies. However, the normal ranges of the ABI in healthy populations and ABI criteria for the diagnosis of PAD in large population studies have not been critically evaluated. Methods and Results The San Luis Valley Diabetes Study (SLVDS) was designed to evaluate the prevalence and complications of non–insulin-dependent diabetes mellitus (NIDDM) in a biethnic population. The present study was conducted as part of the SLVDS to assess the prevalence of vascular disease in 1280 nondiabetic control subjects and 430 patients with NIDDM. The ABI criteria for PAD were developed in 403 healthy individuals with a low risk for cardiovascular disease. In these low-risk subjects, the average resting ABI value was 0.07 lower in women than in men. In both sexes, the dorsalis pedis ABI was 0.04 lower than in the posterior tibial artery, and the left leg ABI was 0.02 lower than the right leg ABI (all differences, P<.05). In the low-risk subjects, ABI values were lower after exercise than at rest and had similar differences by sex and leg as observed at rest. Using specific abnormal cutoff points for the ABI, we evaluated three criteria for PAD in the overall population: two abnormal vessels in the same leg at rest (both dorsalis pedis and posterior tibial arteries), one abnormal vessel per leg at rest, and an ABI abnormality only after exercise. Subjects classified with PAD by the two-vessel criterion had a higher frequency of claudication and the physical finding of an absent pulse compared with subjects without PAD or patients with PAD defined by the one-vessel or exercise criterion. Use of the two-vessel criterion identified an increased risk of PAD with increasing age, NIDDM, smoking, hypertension, and elevated cholesterol levels. In contrast, the one-vessel PAD criterion was associated only with increasing age and smoking, and exercise-diagnosed PAD was not associated with any cardiovascular risk factor except for male sex. Conclusions In low-risk subjects, the normal distribution and lower abnormal cutoff point values of the ABI differed by type of test, sex, ankle vessel, and leg. When these specific abnormal cutoff points were applied to the SLVDS population, the two-vessel abnormal criterion described patients with typical clinical characteristics of PAD and the expected associations of PAD with cardiovascular risk factors. These clinical characteristics and cardiovascular risk factor associations were less evident with PAD diagnosed by the one-vessel or exercise criterion. Therefore, an abnormal dorsalis pedis and posterior tibial ABI in the same leg at rest should be used for the diagnosis of PAD in epidemiological studies.

• Holland-Letza T, Endres HG et al: Reproducibility and reliability of the ankle-brachial index as assessed by vascular experts, family physicians and nurses. Vasc Med 12:105-12, 2007. The reliability of ankle-brachial index (ABI) measurements performed by different observer groups in primary care has not yet been determined. The aims of the study were to provide precise estimates for all effects influencing the variability of the ABI (patients' individual variability, intra- and inter-observer variability), with particular focus on the performance of different observer groups. Using a partially balanced incomplete block design, 144 unselected individuals aged > or = 65 years underwent double ABI measurements by one vascular surgeon or vascular physician, one family physician and one nurse with training in Doppler sonography. Three groups comprising a total of 108 individuals were analyzed (only two with ABI < 0.90). Errors for two repeated measurements for all three observer groups did not differ (experts 8.5%, family physicians 7.7%, and nurses 7.5%, p = 0.39). There was no relevant bias among observer groups. Intra-observer variability expressed as standard deviation divided by the mean was 8%, and inter-observer variability was 9%. In conclusion, reproducibility of the ABI measurement was good in this cohort of elderly patients who almost all had values in the normal range. The mean error of 8-9% within or between observers is smaller than with established screening measures. Since there were no differences among observers with different training backgrounds, our study confirms the appropriateness of ABI assessment for screening peripheral arterial disease (PAD) and generalized atherosclerosis in the primary case setting. Given the importance of the early detection and management of PAD, this diagnostic tool should be used routinely as a standard for PAD screening. Additional studies will be required to confirm our observations in patients with PAD of various severities.

• Horwitz O and Abramson DG: A modification of the vasodilatation test. Am J Cardiology 6:663, 1960. Patients warmed under blankets with toes bare in a 20 degree Centigrade constant temperature room. Toe temperatures: degree of impairment: none >30, slight 28-30, moderate 25-28 and severe 21-25 degrees centigrade. Amputation seldom necessary with results over 26 degrees centigrade.

• Jawahar D, Rachamalla HR, Rafalowski A, Ilkhani R, Bharathan T, and Anandarao N: Pulse oximetry in the evaluation of peripheral vascular disease. Angiology 48: 721-724, 1997. Abbreviated abstract: Pulse oximeter readings in the toes were obtained in 40 young healthy volunteers and 40 patients. All the normal volunteers had normal pulse oximeter readings, which were defined as >95% O2 Sat and ± 2 of finger pulse oximetry readings. In all 40 patients, pulse oximetry readings were either normal or not detected at all. Since there was no gradation in decrease in the pulse oximetry reading with severity of disease or with elevation of the patient's lower extremity, an absent or no reading was considered as an abnormal result from the test. In patients with an ankle/arm index of 0.5 to 0.9, 16% had abnormal baseline readings and an additional 12% had abnormal readings when the limb was elevated 12 inches. For patients with an ankle/arm index < 0.5, 54% had abnormal baseline readings and an additional 23% had abnormal readings with the limb elevated 12 inches. Pulse oximetry was not a sensitive screening test for detecting early PVD.

• Joensen JB, Juul S et al: Doppler ultrasound compared with strain gauge for measurement of systolic ankle blood pressure. Angiology 59:296-300, 2008. This study assesses measurement variation in the measurement of ankle systolic blood pressure (ABP) when measured with Doppler ultrasound and with the strain gauge method. Ninety-seven patients were included. ABP was measured with Doppler ultrasound and with the strain gauge method. The methods were compared graphically by scatterplots and analyzed by paired t test, analysis of variance, and Pitman's paired variance ratio test. ABP was measured by strain gauge in all extremities, whereas no Doppler signal was obtainable in 7 limbs (4%). There was no systematic difference in measurements between the means of the two measurements. However, a substantial difference of more than 25 mm Hg was found in 15% of limbs and more than 20 mm Hg in 20%. In the majority of patients, measurements of ABP by Doppler ultrasound and the strain gauge method give similar results, but for a minority the discrepancy is substantial.

• Johnson WC, Watkins MT, Baldwin D, Hamilton J: Response to Lumbar Sympathectomy in Patients with Focal Ischemic Necrosis. Surg 12:70-74, 2004. Abstract: We prospectively evaluated all patients with superficial foot necrosis of 1-3 cm and transcutaneous oxygen tension (TcPO2) values of <30 mmHg who received a sympathectomy as the primary treatment of their vascular occlusive disease. Preoperatively, and every 2-3 days in the postoperative period, measurement of TcPO2 of the forefoot was performed. Clinical success was defined as healing of the necrosis or healing of a toe amputation and avoidance of a major below-knee/above-knee amputation for 1 year. Ten patients were available for long-term evaluation. During the first 4-5 days, all patients increased their foot TcPO2 and the mean increase (23 mmHg) was significant (p = 0.04). Clinical improvement was marked by an average increase of 29 mmHg by postoperative day 10. In contrast, patients with clinical failure had only an average increase of 5 mmHg in TcPO2 by the same postoperative interval. Preoperative increase in TcPO2 by at least 20 mmHg in response to dependency predicted a favorable response to sympathectomy. In addition, sustained postoperative increases in tissue oxygen levels by postoperative day 10 also favored wound healing.Comments: See our section on diabetic neuropathy for articles showing sympathectomy may be associated with a decrease in PO2. Here we have patients presenting with lesions undergoing sympathectomy in the hospital. Could it be that they were also given antibiotics that treated varying degrees of cellulitis by aerobic organisms? Such a mechanism would raise PO2 independent of the sympathectomy.

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• Jorgensen RG et al: Early detection of vascular dysfunction in type I diabetes. Diabetes 37:292-296, 1988. Blood flow and transcutaneous PO2 measured by venous occlusion plethysmography & transcutaneous O2 electrode before and after 5 minutes of arterial occlusion in the forearm. Controls increase 2.8-fold 30 seconds post ischemia. Diabetics with HbAC under 9.5 approximated normals. Diabetics with HbAC >12.5 did not increase post ischemia. Sex difference noted with less post-ischemic rise in flow and longer subnormal PO2 in females. 4 diabetic patterns described.

• Kalani M, Brismar K, Fagrell B, Ostergren J and Jorneskog G: Transcutaneous oxygen tension and toe blood pressure as predictors for outcome of diabetic foot ulcers. Diabetes Care 22: 147-151, 1999. Authors summary: Results: Of 13 patients who deteriorated, 11 had TcPO2<25 mm Hg, while 34 of the 37 patients who improved had TcPO2 >25 mmHg. The sensitivity and specificity for TcPO2 were 85 and 92%, respectively, when a cutoff level of 25 mmHg was used for determination of outcome of ulcer healing (healing or nonhealing). The corresponding values for TBP at 30 mmHg were 15 and 97%. Measurement of TcPO2 provided a higher positive predictive value (79%) than TBP (67%). Conclusions: The results indicate that TcPO2 is a better predictor for ulcer healing than TBP in diabetic patients with chronic foot ulcers, and that the probability of ulcer healing is low when TcPO2 is <25 mmHg.

• Karnafel W, Juskowa J, Maniewski R, Liebert A, Jasik M, Zbiec A: Microcirculation in the diabetic foot as measured by a multichannel laser Doppler instrument. Med Sci Monit 8(7):MT137-44, 2002. BACKGROUND: The purpose of this study was to investigate microvascular perfusion in insulin-dependent diabetic patients at various locations on the foot, and to determine which part of the foot is most sensitive to microangiopathic changes. All the parameters of postocclusive reactive hyperemia calculated from multichannel laser Doppler recordings were also evaluated to find the most valuable measure for diabetes examination. MATERIAL/METHODS: Our study involved 65 subjects divided into four subgroups: male and female controls, and male and female IDDM patients without overt complications. The measurements were performed with a multichannel laser Doppler perfusion monitor using surface probes located in the distal parts of the lower limbs. The occlusion test was performed using a cuff located on the limb above the knee. Multivariate discriminatory analysis was used to evaluate the data. RESULTS: The most valuable data were obtained by recordings from the laser-Doppler probes located on the hallex and the base of the little toe. The maximum hyperemic response for both sex subgroups was significantly lower in the diabetic patients. The time to peak flow was higher in male diabetics. The half-time for hyperemia was significantly longer in the male diabetic patients. CONCLUSIONS: The females showed smaller changes in foot perfusion than the males, probably due to protection by estrogens. The best locations for perfusion measurement are the most distal, especially the hallex and the base of the little toe. The most valuable parameters of postocclusive hyperemia were maximum response, time to peak flow, and half-time of hyperemia.

• Knighton DR, Silver IA and Hunt TK: Regulation of wound-healing angiogenesis- Effect of oxygen gradients and inspired oxygen concentration. Surgery 90: 262-270, 1981. Using a rabbit ear model, the authors showed that a hypoxic tissue gradient was mandatory for wound-healing angiogenesis, that capillary growth ceases when the hypoxic tissue gradient is destroyed and that inspired oxygen concentrations affect the rate and density of capillary growth.Comment: The data suggests that successful bypass procedures may decrease angiogenesis.

• Knighton DR, Hunt TK, Scheuenstuhl H, Halliday BJ, Werb Z, and Banda MJ: Oxygen tension regulates the expression of angiogenesis factor by macrophages. Science 221:1283-1285, 1983. Rabbit macrophages cultured at various oxygen tensions in vitro and angiogensis effects measured in the cornea.

• Lalka SG et al: Transcutaneous oxygen and carbon dioxide pressure monitoring to determine severity of limb ischemia and to predict surgical outcome. J Vasc Surg 1988; 7: 507-14. TcPO2 and foot/chest TcPO2 was found to be more sensitive to degrees of ischemia and more closely associated with the outcome of revascularization than ankle BP and ankle-brachial index. TcPCO2 and TcPO2/TcPCO2 not useful. Preoperative TcPO2 less than or equal to 22 and foot/chest less than or equal to 0.46 indicated severe ischemia requiring bypass. Postoperative TcPO2 less than or equal to 22 and foot/chest less than 0.53 indicated revascularization likely to fail.

• Landry GJ, Moneta GL, Taylor LM Jr et al: Duplex scanning alone is not sufficient imaging before secondary procedures after lower extremity reversed vein bypass graft. J Vasc Surg 29:270-80, 1999. PURPOSE: Duplex surveillance of lower extremity reversed vein bypass grafts (LERVG) is a means of identifying patients at risk for occlusion. The perceived accuracy of duplex scan as a means of identifying stenoses has led many surgeons to perform graft revision on the basis of duplex scan alone. This may result in missing additional lesions that are threatening patency. To assess the role of duplex scan as the sole imaging method before revision of LERVGs, we reviewed consecutive patients undergoing revisions who underwent preoperative arteriography after identification of duplex scan abnormalities. METHODS: Duplex scan results, operative reports, and preoperative arteriograms for patients undergoing LERVG revision from January 1990 to December 1997 were reviewed. A standard duplex scan surveillance protocol was followed, and attempts were made to survey the entire graft, including inflow and outflow. Duplex scan results were compared with the results of preoperative arteriograms and the operation performed to determine if all significant lesions were identified by means of duplex scan alone. RESULTS: Two hundred five LERVG revisions were performed. The 5-year assisted primary patency rate was 91%. In 119 cases (58%), arteriography did not contribute significantly to duplex scan findings. Arteriography significantly contributed to operative planning in 86 cases (42%). In 38 cases (19%), only a low-flow state was identified by means of duplex scan, and a correctable stenosis was identified by means of arteriography. In 48 cases (23%), additional significant lesions corrected at operation were identified by means of arteriography. These included 26 inflow, 16 graft, and 8 outflow lesions. Arteriography was most useful as a means of determining the revision procedure performed when there were inflow lesions (P <.05) or when the proximal anastomosis was to the profunda or superficial femoral arteries (P <.05). All frequently performed bypass graft configurations had some discrepancy between arteriographic and duplex scan findings. CONCLUSION: Available data do not permit prediction of which LERVG are immune from missed lesions in a duplex scan surveillance protocol. This suggests to us that arteriography is mandatory before LERVG revisions.

• Larsson J. Apelqvist J, Castenfors J, Agardh C-D and Stenstrom A: Distal blood pressure as a predictor for the amputation in diabetic patients with foot ulcer. Foot & Ankle 14: 247-253, 1993. 161 consecutive patients with foot ulcers. Outpatient care except for perioperative periods. Ankle or toe BP's available in 86% of patients. An absolute ankle BP of 50mm Hg was found below which a minor amputation was never sufficient to achieve healing. An ankle blood pressure below 75mm Hg was seldom sufficient and at or above that pressure level, the ankle pressure had no predictive value. At a toe pressure below 15mm Hg, a minor amputation was seldom sufficient. Ankle and toe pressure indices gave no further information.

• Lawall H, Amann B, Rottmann M, Angelkort B: The role of microcirculatory techniques in patients with diabetic foot syndrome. Vasa 29:191-7, 2000. BACKGROUND: Diabetic foot syndrome (DFS) is a frequent complication of long-standing diabetes mellitus, occurring in 10 to 30 percent of all diabetics with a vital risk for the affected limb and high mortality rates. Macroangiopathy, diabetic polyneuropathy and infections are trigger factors for DFS. Recent results imply a pathogenic role of functional and structural microcirculatory changes. The exact role of microangiopathy and the value of microcirculatory diagnostic methods in DFS have not yet been defined. PATIENTS AND METHODS: 78 patients with DFS (28 type I, 50 type II diabetics, mean age 63 years) were evaluated with video capillary microscopy, transcutaneous partial oxygen tension (tcpO2) measurement and laser Doppler fluxmetry (LDF) at the forefoot of the affected leg at admission and after revascularisation. Mean hospital stay was 28 +/- 11.7 days. Patients were stratified according to the etiology of DFS in patients with neuropathic lesions, macroangiopathic ulcers and mixed neuropathic-angiopathic lesions. RESULTS: All groups had impaired microcirculation, and significant differences between groups were found in respect to capillary density. Reactive hyperemia, LDF pattern and tcpO2 did not differ significantly. Microcirculatory examinations did not yield additional information to clinical and Doppler sonographic results. CONCLUSION: In clinical practice, the role of microcirculation evaluation techniques for diabetic foot syndrome is limited.Comments: In these patients destined for revascularization, microvascular evaluations were abnormal but of no help over standard vascular tests to the clinician

• Lilly MP, ReichmanW, Sarazen AA Jr, Carney WI Jr: Anatomic and clinical factors associated with complications of transfemoral arteriography. Annals of Vascular Surgery 4: 264-269, 2005. Abstract Complications of transfemoral arteriography requiring surgery are rare but carry significant morbidity. To evaluate clinical factors that might relate to such complications, we retrospectively reviewed our experience from January 1, 1985, to December 31, 1988 (four years). Forty-seven complications requiring surgery occurred among 10,589 cases. The risk was higher after cardiac catheterization than after peripheral arteriography (0.55% versus 0.17%, p<0.025). In nearly 40% of these cases, arterial puncture was not in the common femoral artery. Acute bleeding complications were more likely among patients with puncture outside the common femoral artery (p<0.001). Older patients and women were at slightly higher risk for complications requiring surgery, but this difference was not statistically significant. The frequency of bleeding complications was not significantly higher among patients who were anticoagulated following the procedure. The distribution of puncture sites was identical in obese and nonobese patients. Three patients died (two from myocardial infarction, one from multisystem organ failure). Two limbs did not improve; one required major amputation. Four limbs had persistent paresthesia and two had persistent weakness. We conclude that complications of transfemoral arteriography requiring surgery occur more frequently among patients who are undergoing cardiac catheterization and who suffer aberrant punctures. Age, sex, body habitus, and anticoagulation have less impact on patient risk.

• Linge K, Roberts DH and Dowd GSE: Indirect measurement of skin flow and transcutaneous oxygen tension in patients with peripheral vascular disease. Clin Phys Physiol Meas 1987, 8:293-302. With the electrode at 44 degrees Centigrade on the legs during treadmill exercises, electrode heat consumption correlated closely with the degree of exercise. In normals TcPO2 same on the dorsum of the foot, the leg and the chest. Stump tissue failed to heal if the TcPO2 was 40mm Hg.

• Lowery AJ, Hynes N, Manning BJ et al: A prospective feasibility study of duplex ultrasound arterial mapping, digital-subtraction angiography, and magnetic resonance angiography in management of critical lower limb ischemia by endovascular revascularization. Ann Vasc Surg 21:443-51, 2007. Abstract: Duplex ultrasound arterial mapping (DUAM) allows precise evaluation of peripheral vascular disease (PVD). However, magnetic resonance angiography (MRA) and digital-subtraction angiography (DSA) are the diagnostic tools used most frequently prior to intervention. Our aim was to compare clinical pragmatism, hemodynamic outcomes, and cost-effectiveness when using DUAM alone compared to DSA or MRA as preoperative assessment tools for endovascular revascularization (EvR) in critical lower limb ischemia (CLI). From 2002 through 2005, 465 patients were referred with PVD. Of these, 199 had CLI and 137 required EvR. Preoperative diagnostic evaluation included DUAM (n = 41), DSA (n = 50), or MRA (n = 46). EvR was aortoiliac in 27% of cases and infrainguinal in 73%. Patients were assessed at day 1, 6 weeks, 3 months, and 6 months. Composite end points were relief of rest pain, ulcer/gangrene healing, and increase in perfusion pressure, as measured by ankle-brachial index (ABI) and digital pressures. Patency by DUAM, limb salvage, morbidity, mortality, length of stay, and cost-effectiveness were compared between groups using nonparametric t-test, analysis of variance, and Kaplan-Meier analysis. The three groups were comparable in terms of age, sex, comorbidity, and Society for Vascular Surgery/International Society of Cardiovascular Surgery clinical classification. Six-month mean improvement in ABI in the DUAM group was comparable to that in the DSA group (P = 0.25) and significantly better than that in the MRA group (P < 0.05). Six-month patency rates for the DUAM group were comparable to those in the DSA group (P = 0.68, relative risk [RR] = 0.74, 95% confidence interval [CI] 0.18-2.99) and superior to that in the MRA group (P = 0.022, RR = 0.255, 95% CI 0.09-0.71). Length of hospital stay was lower in the DUAM group compared with the DSA group (P < 0.0001) and the MRA group (P = 0.0003). The cost of DUAM is lower than that of both DSA and MRA. DUAM accurately identified the total number of target lesions for revascularization; however, MRA overestimated it. Our results indicate that DUAM is outstanding when compared with other available modalities as a preoperative imaging tool in a successful EvR program. DUAM is a minimally invasive preoperative evaluation for EvR and offers precise consecutive data with patency and limb salvage rates comparable to EvR based on DSA and superior to MRA. We believe that our feasibility study has established DUAM as an economically proficient primary modality for investigating patients with CLI that significantly shortens length of hospital stay.

• Mahutte CK, Michiels TM, Hassell KT and Trueblood DM: Evaluation of a single transcutaneous PO2-PCO2 sensor in adult patients. Critical Care Med 12: 1063-1066, 1984. Least-squares linear regression relations between transcutaneous and arterial gases: PtcO2=0.52PaO2 + 22.5 (r= 0.57); PtcCO2=0.98PaCO2+ 4.52 (r=0.94). Overall 47 adult ICU patients. Simultaneous TcPO2 and PaO2 levels obtained within 4 hours of in vivo calibration ranged from 36-156 (the bulk 50-90) and 44-130 (the bulk 50-90) respectively.

• Malone JM, Anderson GG, Lalka SG, Hagaman RM, Henry R, McIntyre KE and Bernhard VM: Prospective comparison of noninvasive techniques for amputation level. AM J Surgery 1987, 154:179-184. TcPO2, TcPCO2, TcPO2/TcPCO2 and Foot/Chest TcPO2 all statistically different between healed and failed groups. Xenon-133 clearance, ABI and absolute popliteal BP were not reliable indicators of amputation healing. TcPCO2 not reliable above the knee. All amputation sites with a TcPO2 => 20 Torr healed and none of 11 below 20 healed. All with TcPCO2 less than 31 Torr healed ; 79% in the 31-41 Torr healed; and 4/4 with values greater than 41 failed to heal. A TcPO2/TcPCO2 value > 0.6 healed in all 39 cases while an index below 0.6 failed in 7 of 13. For foot/chest TcPO2, 100% healed with values over 0.50 and 11/13 failed to heal with values under 0.50. The diagnostic cutoff points for predicting healing were TcPO2 20, TcPCO2 40.5, TcPO2/TcPCO2 0.472 and foot/chest TcPO2 0.442.

• Marinelli MR, Beach KW, Glass MJ, Primozich JF and Strandness DE: Noninvasive testing vs clinical evaluation of arterial disease, A prospective study. JAMA 241: 2031-2034, 1979. 458 diabetic patients studied. Nearly a third of those with no history of intermittent claudication had abnormal arterial tests. One fifth of those with a normal physical examination had abnormal testing. "Abnormal" if arm/ankle index below 0.95, post treadmill ankle BP less than or equal to 0.8 at one minute or a low ankle BP at 3 minutes, or monophasic Doppler waveforms.

• Mars M, McKune A, Robbs JV: A comparison of laser Doppler fluxmetry and transcutaneous oxygen pressure measurement in the dysvascular patient requiring amputation. Eur J Vasc Endovasc Surg. 16(1):53-8, 1998. OBJECTIVE: To determine the predictive power of laser Doppler fluxmetry (LDF), both heated and unheated, as a preoperative investigation of wound healing potential in dysvascular patients requiring amputation, by comparison with transcutaneous oxygen pressure measurement (TcpO2) and the limb to chest TcpO2 index. METHODS: Thirty-five non-diabetic patients with peripheral vascular disease were investigated before amputation. Heated and unheated LDF and heated TcpO2 measurements were taken on the chest wall and at the routine above-knee, below-knee and mid-foot amputation levels. Wound healing potential was evaluated against a TcpO2 index value of 0.55 and on clinical outcome. RESULTS: A heated LDF value of 4.9 arbitrary units (au) was shown by receiver-operator characteristic curve to have the best predictive power, with an overall accuracy for preoperative prediction of wound healing of 91.4%, and a predictive value for wound failure of 89%. Based on the heated LDF of 4.9 au, review of 26 amputations performed shows the overall accuracy for preoperative prediction of wound healing of 92.3%, a predictive value for wound healing of 100%, and a predictive value for wound failure of 62.5%. CONCLUSION: A heated LDF value of 4.9 au appears to be a useful predictor of the potential of an amputation site to heal.

• Mason RA, Arbeit LA and Giron F: Renal dysfunction after arteriography. JAMA 253:1001-1004, 1985. A prospective study in which creatinine clearance measured immediately before and after 120 arteriographic procedures. 31% of the patients sustained a 25% or more reduction in clearance after the procedure generally of a transient nature. Only 3% developed overt renal failure but generally in association with other risk factors. Patients with diabetes or pre-existing renal disease were not at greater risk. Again no correlation existed between the total dose of contrast media and the degree of renal dysfunction.Comments: It is unfortunately not uncommon for a diabetic with significant renal impairment to require dialysis after the administration of contrast media. Tepel et al (N Engl J Med 343: 180-4, 2000) tell us that the prior administration of the antioxidant acetylcysteine in doses of 600 mg twice daily on the day before and on the day of the arteriogram, along with hydration prevented a reduction in renal function after the administration of iopromide, a nonionic, low-osmolality contrast agent.

• Mazzariol F, Ascher E, Hingorani A, Gunduz Y, Yorkovich W, Salles-Cunha S: Lower-extremity revascularisation without preoperative contrast arteriography in 185 cases: lessons learned with duplex ultrasound arterial mapping. Eur J Vasc Endovasc Surg 19(5):509-15, 2000. PURPOSE: we have previously reported our experience with lower-extremity duplex-ultrasound arterial mapping (DUAM) compared to contrast arteriography (CA) to predict lower-extremity bypass sites. The present study evaluates arterial revascularisation procedures for chronic limb ischaemia based on DUAM. MATERIALS AND METHODS: from January 1998 to July 1999, 195 patients (128 men, 67 women) underwent 211 lower-extremity revascularisation procedures based on DUAM. Indications for surgery were tissue loss, severe claudication, rest pain and popliteal aneurysm in 57%, 25%, 14% and 4% of the limbs, respectively. The mean age was 72+/-12 years and risk factors such as diabetes, hypertension, tobacco use, coronary artery and end-stage renal disease were present in 53%, 58%, 53%, 50% and 12% of the patients, respectively. Previous revascularisation procedures had been performed in 23% of the limbs. Preoperative evaluation consisted of DUAM alone (185) or of a combination of DUAM and CA (29 limbs). CA was deemed necessary due to a combination of technical difficulties that jeopardized adequate sonographic imaging and presence of disadvantaged run-off for medico-legal reasons. DUAM consisted of direct imaging of all major arteries from the distal aorta to the pedal circulation. Optimal inflow and outflow bypass anastomotic sites were selected according to a diagram based on DUAM. Adequacy of the inflow was additionally assessed by common-femoral-artery waveform and confirmed by intraoperative pressure measurements. Post-bypass CA was obtained to verify patency of the run-off. RESULTS: DUAM procedure time averaged 75+/-26 min. For patients who underwent only DUAM, the distal anastomosis was to the popliteal artery in 91 cases and to tibial or pedal arteries in 58 cases. Distal anastomosis was proximal to a significant lesion in two cases that required jump grafts. Cumulative patency rates at 1 and 3 months for popliteal bypasses were 96% and 90%, and for infrapopliteal bypasses 90% and 83%, respectively. Inflow procedures to the femoral artery, patch and balloon angioplasties accounted for the remaining 40 cases. Four primary amputations were performed after CA confirmed DUAM findings. CONCLUSIONS: contrary to general belief, these data show that high-quality arterial ultrasonography represents a safe alternative to preoperative CA, even for infrapopliteal bypasses. This non-invasive approach may be especially useful for patients with contrast allergy or impaired renal function.

• Nilsson SK: Skin temperature over an artificial heat source implanted in man (applied to IR thermography).Phys. Med.Biol 20: 366-83, 1975. Abstract. The medical application of infrared thermography makes use of the skin temperature as an indication of an underlying pathological process. In order to study the relation between the heat production from a source in living tissue and the overlying skin temperature, artificial heat sources were implanted subcutaneously in human volunteers. The experimental results show that a detectable surface temperature increase over the heat sources presupposes high power output or superficial implantation. The effect of forced convective heat loss from the skin surface and lowered ambient temperature was studied. Forced convection markedly decreased the temperature contrast. An implicit conclusion from experimental and theoretical work is that a localized 'hot spot' can only exceptionally be attributed to metabolic heat production conducted to the skin surface from a buried pathological process. Comments: An interesting study that likely would not be allowed by todays' research committees

• Novametrix Medical Systems Inc: Common question regarding transcutaneous monitoring. PtcO2=80%PaO2 (79+/-12%). PtcCO2=160%PaCO@. The PtcO2 value follows the PaO2 value in perhaps a minute.

• Nukumizu Y, Matsushita M, Sukurai T et al: Comparison of Doppler and oscillometric ankle blood pressure measurement in patients with angiographically documented lower extremity arterial occlusive disease. Angiology58:303-308, 2007. To assess the reliability of the oscillometric method in patients with peripheral vascular disease, ankle blood pressure measurement by Doppler and oscillometry was compared. This study represents a prospective, non-blinded examination of pressure measurements in 168 patients. Twenty-two patients were included who had abdominal aortic aneurysms (AAA) and 146 had peripheral arterial occlusive disease (PAOD). Patients with PAOD were divided into 2 groups according to angiography results: a crural artery occlusion group (CAO, n = 32), and a no crural artery occlusion group (NCAO, n = 114). All subjects underwent pressure measurement by both Doppler and oscillometry. The correlation coefficient was 0.928 in AAA patients and 0.922 in PAOD patients. In CAO patients, there were significantly fewer patients whose oscillometric pressure was equivalent to the Doppler pressure (DP), as compared to NCAO patients, because the oscillometric pressure (OP) was 10% higher than DP in 44% of CAO patients. A high correlation exists between Doppler and oscillometric ankle pressure measurements irrespective of the type of vascular disease. However, the oscillometric method could not be substituted for the Doppler method completely, because there were several patients whose OP was greater than DP especially in those with crural artery occlusive disease.

• Nzeh DA, Allan PL, McBride K, Gillespie I, Ruckley CV: Comparison of colour Doppler ultrasound and digital subtraction angiography in the diagnosis of lower limb arterial disease. Afr J Med Med Sci 27(3-4):177-80, 1998. A fifteen-month retrospective review (December 1993 to February 1995 inclusive) was performed comparing findings at Colour Doppler Ultrasound (CDU) and Digital Subtraction Angiography (DSA) in patients with symptomatic peripheral arterial disease or post-operative by-pass grafts. The records of 63 patients (43 males and 20 females) who had undergone both CDU and DSA within three months of each other were analysed. The age range of case studied was 33-84 years (mean 64 yrs.) Disease in each arterial or graft segment was classified into five grades, 0 (normal) to 4 (complete occlusion). A total of 72 limbs were examined. Fifty-four patients had unilateral symptoms while both limbs are affected in 9 cases. In all 241 arterial and graft segments were studied. There was overall agreement between findings of CDU and DSA in 193/241 (80/1%) and non-agreement in 48/241 (19.9%). Of the 48 examinations that showed discrepancy, the findings in 26/48 (54.2%) were one grade apart while in the remaining 22/48 (45.8%) there was a difference of two or more grades. Agreement between CDU and DSA in the individual arterial segments studied was as follows: common femoral 42/48 (87.5%); profunda femoris 19/25 (76.0%); superficial femoral 27/39 (81.0%); anterior tibial 17/81 (94.4%) and peroneal 15/17 (88/2%). In the grafts, there was an agreement of 20/27 (74/1%) between CDU and DSA. These results show a good correlation between the two imaging modalities with complete agreement and agreement within one grade in 80.1% and 90.9% of cases, respectively, confirming that CDU can be employed as a useful screening technique for assessment of symptomatic patients, allowing selection of patients for angioplasty alone or angiography for arterial mapping or those who require by-pass graft surgery.

• Ohnishi H, Saitoh S, Takagi S, Ohata J, Isobe T, Kikuchi Y, Takeuchi H, Shimamoto K: Pulse wave velocity as an indicator of atherosclerosis in impaired fasting glucose: the Tanno and Sobetsu study. Diabetes Care 26:437-40, 2003. OBJECTIVE: Brachial-ankle pulse wave velocity (baPWV), as an indicator of atherosclerosis in impaired fasting glucose (IFG), was studied in 232 subjects randomly selected from inhabitants of two rural communities in Japan. RESEARCH DESIGN AND METHODS: BMI, systolic blood pressure (SBP), fasting blood glucose (FBS), lipid parameters, ankle brachial pressure index (ABI), and baPWV were measured in each subject. ABI and baPWV were measured using the recently developed device, form ABI/PWV. The subjects were divided into three groups according FBS level: a normal group consisting of subjects with FBS <110 mg/dl, an IFG group consisting of subjects with FBS 110-125 mg/dl, and a diabetic group consisting of subjects with FBS > or =126 mg/dl and subjects taking hypoglycemic agents. The parameters in the three groups were compared. RESULTS-It was found that the baPWV value increased with increasing plasma glucose level. Significant differences were found between the baPWV values in the normal and IFG groups (1,518 vs. 1,673 cm/s, P = 0.01) and in the normal and diabetic groups (1,518 vs. 1,771 cm/s, P < 0.0001). The results of multiple regression analysis showed that FBS was closely related to baPWV as well as to age and SBP. CONCLUSIONS: The relationship between IFG and atherosclerosis remains controversial. Further studies are needed to evaluate whether strict control of blood glucose level in patients with IFG will result in the prevention of atherosclerosis progression. Comments: We are so accustomed to observing decreased velocities in patients with obstructive arteriosclerotic lesions that we forget that increased velocities are bad also.

• Oishi CS, Fronek A, Golbranson FL: The role of non-invasive vascular studies in determining levels of amputation. J Bone Joint Surg AM. 70: 1520-30, 1988.Various non-invasive vascular studies have been reported to provide valuable data for selection of the optimum level of amputation in limbs in patients who have vascular disease. We evaluated three such methods: (1) measurement of the change in the transcutaneous PO2 after inhalation of oxygen; (2) determination, by the Doppler method, of segmental blood pressure; and (3) measurement of the temperature of the skin. The records of eighty patients (ninety amputations) were retrospectively reviewed for correlations between the results of the vascular studies and the outcome of the amputation. Measurement of transcutaneous PO2 was found to be the most accurate predictor of successful healing of an amputation; the other two measurements were less reliable. The values for transcutaneous PO2 both at rest and after inhalation of oxygen were significantly different (p less than 0.001) for the patients who had a healed amputation compared with those who had a failed amputation. Regardless of the initial value, if, after inhalation of oxygen, the transcutaneous PO2 reached ten millimeters of mercury or more, it predicted healing of the amputation stump with a sensitivity of 98 per cent. When the level of amputation was selected on the basis of clinical judgment at the time of operation, the sensitivity was only 90 per cent.

• Pahlsson HI, Wahlberg E, Olofsson P, Swedenborg J: The toe pole test for evaluation of arterial insufficiency in diabetic patients. Eur J Vasc Endovasc Surg 18:133-7, 1999. OBJECTIVES: to evaluate if the pole test at the toe level can be used for assessment of arterial insufficiency in diabetic patients. METHODS: twenty-five legs in 23 diabetic patients suffering from leg ischaemia were examined prospectively. A laser Doppler probe was attached to the pulp of the first toe to monitor perfusion continuously before and after occluding the arterial inflow with a cuff and during elevation of the leg until perfusion disappeared (the pole test). At ankle level the examinations were made similarly but with an ankle cuff and a hand-held Doppler. RESULTS: in the 44% (11/25) of the legs where it was possible to compare cuff blood pressure at ankle level with the pole test, the cuff measurements were significantly higher (p <0.01). In 13 of the remaining 14, maximal elevation did not result in disappearance of the Doppler signal. At toe level where 76% (19/25) of the legs could be compared, there was no significant difference between the two methods. CONCLUSION: the pole test can be used at the toe level to evaluate arterial insufficiency in diabetes. When used in the toe, the pole test can assess pressures below 55-70 mmHg, while only pressures below 45 mmHg can be determined at the ankle level. Falsely elevated blood pressure in diabetics is probably of less importance in digital arteries than in ankle arteries, which makes cuff pressure at toe level a more acceptable approximation. Comments: Pallor on elevation, of course, is an important finding on the physical examination of the patient. A laser Doppler or a PPG sensor can be used to accurately measure the height above the examining table at which pulsations disappear providing an accurate assessment of true perfusion pressure and a quick screening procedure.

• Påhlsson HI, Jörneskog G, Wahlberg E: The cuff width influences the toe blood pressure value. Vasa 33(4):215-8, 2004. BACKGROUND: Toe blood pressure is a valuable and often used parameter when lower limb ischaemia is evaluated in patients with diabetes, but little has been done to standardise the method. The aim of this study was to evaluate if the cuff size influences the toe blood pressure values obtained in patients with diabetes. PATIENTS AND METHODS: Eleven patients with diabetes without a history of peripheral vascular disease, and six age matched healthy subjects were investigated. Their blood pressures were measured in the upper arm and at the ankle level repetitively. For measurement of toe blood pressure two different cuff widths were used. RESULTS: All blood pressures were similar in patients and control subjects, as well as over time. The toe blood pressure values were 18 mmHg higher (p < 0.01) if measured with a 2.0-cm compared to a 2.5-cm wide cuff. There was a relationship (r = 0.63, p < 0.05 for patients) between toe circumference and the toe blood pressure value, where smaller hallluxes gave lower values. CONCLUSIONS: The cuff width influences the obtained toe blood pressure value and needs to be considered when evaluating limb ischemia in patients with diabetes.

• Påhlsson HI, Laskar C, Stark K, Andersson A, Jogestrand T, Wahlberg E: The optimal cuff width for measuring toe blood pressure. Angiology 58(4):472-6, 2007. To determine the optimal cuff width for measuring toe blood pressure in patients with lower limb ischemia, this experimental prospective study examined 20 patients with symptoms of peripheral arterial disease referred for vascular examination or vascular surgery. Toe blood pressure was measured hydrostatically by the pole test using cuffs of different widths. Pole test reflects the true physiological blood pressure value and was the reference method. Blood pressures obtained using the cuffs were related to this value and to patients' toe circumference. With the 2.5-cm cuff, the patients had a mean pole test toe blood pressure of 28 mm Hg (range, 6-55 mm Hg). Compared with pole test results, the toe blood pressure was 15.6 mm Hg (95% confidence interval [CI], 8-23 mm Hg) higher when measured using the 2.0-cm cuff (P < .001) and 4.5 mm Hg (95% CI, 0-9 mm Hg) higher when measured using the 2.5-cm cuff (P = .07). Using the 1.5-cm and 3.0-cm cuffs, the differences were 27.0 mm Hg (95% CI, 13-43 mm Hg) and -2.0 mm Hg (95% CI, -11 to 8 mm Hg), respectively. The cuff width greatly affects the obtained toe blood pressure value, and larger cuffs correspond better to the hydrostatic pressure. For clinical use and as a reporting standard, we propose that toe blood pressure measurements should be made using a 2.5-cm-wide cuff. Comments: A third article from the same group and observations worth knowing. Patients with ischemic pain commonly find relief in keeping their legs dependent. Persistent dependency promotes edema. All good doctors dislike edema and may advise the patient to elevate the leg. The swelling goes down and the rubor may disappear presumably justifying the instructions of the doctor. Those familar with the "Pole Test", which these authors are using as a gold standard for the evaluation of blood pressure in the diabetic foot, might worry that the foot blanched because the elevation of the foot was sufficient to eliminate blood flow to the distal foot while those not familar with the test might return the next day to find a level line across the distal foot of the patient beyond which the foot had begun to turn black. It happens. And it happens especially in the hemodialysis clinic where removal of too much fluid may promote hypotension and lead the clinic staff to tilt the dialysis chair backwards and elevate the feet. Here the authors used a Laser Doppler to sense the blood flow in the feet after the skin temperature had been warmed above 30-34 decrees C. The clinician and the family of the patient can get the same information by observing capillary refill (the return of color/blood after it has been pressed out of the tissue) which fails if the foot/toe is raised above systolic blood pressure.

• Papankolaoul G, Beach KW, Zierler RE, Strandness E Jr: The relationship between arm-ankle pressure difference and peak systolic velocity in patients with stenotic lower extremity vein grafts. Annals Vasc Surg 9(6):554-560, 1995. Abstract The relationship between the measured arm-ankle pressure difference (AAPD), or the ankle/arm index (AAI), and the focal peak systolic velocity (PSV) at stenotic sites of infrainguinal vein grafts has not been determined. We attempted to relate these two parameters. We used Doppler systolic pressures and duplex ultrasonography to study 35 infrainguinal vein bypass grafts followed in a surveillance protocol. The following graft groups were identified: grafts in non-diabetic patients (n = 26), grafts in diabetic patients (n = 9), nonrevised stenotic grafts (n = 14), revised stenotic grafts (n = 14), and normal grafts (n = 7). AAPD and AAI were measured in both lower extremities. Pressure gradients across graft stenoses were indirectly estimated using the modified Bernoulli equation (DeltaP = 4V2). Measured AAPDs and estimated pressure gradients showed moderate correlation in nondiabetic (r = 0.58) and diabetic (r = 0.63) patients. Correlation was fair (r = 0.3) prior to graft revision. There was no correlation (r = 0.1) in the nonrevised stenotic grafts. For individual patients with stenotic grafts who were followed in consecutive visits, the correlation varied from none to good (r range 0.01 to 0.71). We conclude that there is a lack of consistent correlation between the measured AAPD, or AAI, and the estimated stenotic graft pressure gradient. This finding illustrates the limitation of the AAI as a monitoring test to predict failure of stenotic infrainguinal vein grafts.

• Pecoraro RE, Ahroni JH, Boyke EJ and Stensel VL: Chronology and determinants of tissue repair in diabetic lower-extremity ulcers. Diabetes 40:1305-1313, 1991. 46 diabetic outpatients. The initial healing rate, eventual status of tissue repair and definitive clinical outcome were not significantly associated with age, diabetes type, duration or treatment, level or change in glycosylated hemoglobin, current smoking, presence of sensory neuropathy, ulcer location or class, initial infection, or frequency of recurrent infections. Periwound measurements of transcutaneous O2 (TcPO2) and trancutaneous CO2 tension (TcPCO2) were significantly associated with initial rate of tissue repair ... independent of the effect of segmental Doppler arterial blood pressure at the dorsalis pedis. Concluded that periwound perfusion the critical physiologic determinant for healing. A 39-fold increased risk of failure to heal when average periwound TcPO2 20mm Hg. Comment: Many of the above factors are associated with failure to heal... but not, this study tells us, if tissues gases remain relatively normal.

• Pinzur MS, Stuck R, Sage R, Osterman H: Transcutaneous oxygen tension in the dysvascular foot with infection. Foot Ankle 14:254-6, 1993. Eight adult insulin-requiring diabetics with peripheral vascular disease were admitted with foot infection and signs of systemic sepsis. Transcutaneous oxygen tension was measured at the foot and ankle prior to surgery. None of the values were sufficient to support wound healing. Four of the patients underwent open ray resection and four open midfoot amputation. After resolution of the local infections, transcutaneous oxygen tensions were repeated. Seven of the eight patients exhibited an appreciable increase in the value following decompression of the foot infection, sufficient to support wound healing.Comments: The combination of low TcPO2, high TcPCO2 and pulsatile flow as shown with a PPG probe usually signify cellulitis in our experience and a need for urgent care to avoid tissue necrosis. We meet this need with the injection of local antibiotics and boot therapy.

• Pocock SJ, and Simon R: Sequential treatment assignment with balancing for prognostic factors in the controlled clinical trial. Biometrics 31, 103-115, 1975. Introductory comments: ... (in multicenter studies)... "It is desirable that each medical institution in such a trial have equal numbers of patients on each treatment, both to balance out any 'institutional effect' and also to keep the institutions more interested in the trial. ".. General method: N treatments (N1=boot, N2= Topical oxygen in one proposed Circulator Boot Study). M prognostic factors to be balanced with the number of level of these factors n1, n2, ...nM. Considering an arbitrary point in the assignment of patients to the trial, let Xijk= the number of patients with level j of factor i who have been assigned treatment k for j=1,2,..,ni; i=1,2,...,M and k=1 or 2 (boot, or topical Oxygen) - In considering the next patient entering the trial, let r1,...,rM be the level of factors 1,...,M for this patient. The choice of treatment to be assigned for this patient is determined by examining the effect of the choice on the balance of the study as follows: For each treatment one examines the new (Xijk) that would arise if that treatment were assigned to the patient.

• Raines JK, Darling RC, Buth J, Brewster DC, and Austen WG: Vascular Laboratory criteria for the management of peripheral vascular lesions of the lower extremity. Surgery 79:21-29, 1976. Blood pressure in diabetic at ankle under 80 and unlikely to heal.

• Ramaswami G, Al-Kutoubi A, Nicolaides AN, Dhanjil S, Griffin M, Belcaro G, Coen LD: The role of duplex scanning in the diagnosis of lower limb arterial disease. Ann Vasc Surg 13(5):494-500, 1999. Color flow duplex imaging of the iliac and femoropopliteal arteries was performed in patients undergoing angiography. The aim of the study was to determine: (1) in what percentage of patients could the iliac arteries be adequately visualized to enable a diagnosis, (2) the overall accuracy of duplex scanning in the diagnosis of arterial disease, and (3) whether there is a useful duplex criterion for the selection of patients for angioplasty. One hundred and twenty patients (79 males, 41 females; mean age 64.4 years) had duplex scans prior to angiography (2-7 days) and the results were compared. The duplex criteria of an increase in the peak systolic velocity ratio (PSVR) >2 and lesions <5 cm were used to signify hemodynamically significant stenosis (>50% narrowing), the presence of plaque and calcification in the arterial wall with alteration of PSVR and lesions >5 cm, diffuse disease, and the absence of flow on color/Doppler interrogation, occlusion. The results show that duplex scanning is a useful screening tool and may be effectively used to diagnose iliac and femoropopliteal disease in nearly 80% of patients. Angiography will be needed in those in whom duplex scanning is inconclusive, or, prior to intervention in those with disease suitable for surgical reconstruction or angioplasty, diagnosed on the basis of duplex scans.

• Reimers I, Schmeller W: [Transcutaneous oxygen partial pressure measurement in follow-up of patients with erysipelas]. Hautarzt 41:84-7, 1990. In 24 patients with erysipelas, skin oxygen tension (tcPO2) was measured in the centre, at the border and outside the area of skin inflammation before, during and after antibiotic treatment. At the same time ESR, leucocytes and body temperature were determined. Skin erythema persisted over a period of about 7 days. Leucocytes and body temperature showed normal values after 3 days, while ESR was raised continuously in the first 3 weeks. Skin oxygen tension showed a good correlation with the clinical picture, but was still reduced at the end of therapy. About 2 weeks after disappearance of the clinical signs of inflammation, tcPO2 values were back to normal. The measurement of transcutaneous oxygen pressure can supplement the classic parameters of inflammation as a valuable tool for follow-up examinations in patients with erysipelas. Comments: The TcPO2 determination provides an important physiologic measurement but does not of itself document the presence of peripheral vascular disease. Here excessive utilization of oxygen by infection lowered the value. Heart and lung disease commonly are associated with peripheral cyanosis.

• Rendell M et al: Microvascular blood flow, volume & velocity measured by laser Doppler techniques in IDDM. Diabetes 38:819-24, 1989. Flow greatest in areas with numerous AV anastomoses as in pulp of index finger and 1st toe. Nondiabetic flow> diabetic at most areas at 35 degrees centigrade; difference greater at 44 degrees. In the arm, diabetics had volumes 10-15% lower and velocities 10-40% lower; in the legs, volumes 20-25% and velocities 40-50% lower. Neuropathy made no difference.

• Rhodes GR: Uses of Transcutaneous oxygen monitoring in the management of below-knee amputations and skin envelope injuries (SKI). The Am Surgeon 51:701-707, 1985. Ptc02 values >=25mm Hg were associated with healing of BK amputations. Ptc02 mapping demonstrated values less than 20MM Hg surrounding nonhealing skin. These nonhealing islands of ischemia, occurring after revascularization and associated with adjacent normal pedal Ptc02 values, tended to occur in diabetics with advanced pedal atherosclerosis.

• Rooke TW, Sutor B and Heser BS: Compliance changes in venous insufficiency. Angiology 44: 777-783, 1993. Abstract: In 37 patients (69 limbs) referred to Mayo Clinic's Vascular Center for possible venous valvular insufficiency in the lower limb, calf muscle pump function, calf compliance, and venous filling times were measured by strain gauge plethysmography techniques. Patient limbs were separated into four categories based on 90% refilling time (T90 ) following fifteen deep knee bends: normal (n=16), mild/moderate (n=28), severe (n=16), and edema of nonvenous origin (n=9). Pump function was assessed in actual pumping volume (mL) and in percent pumping volumes mL/100mL), and was reduced in all noncontrol categories. Calf compliance was assessed in actual volume change (mL/mmHg) and in percent volume change (mL/100 mL/mmHg) and was increased in the severe reflux category. Ten study patients had 1 normal category limb and 1 reflux category limb. Paired analysis of these limbs showed pump function to be decreased and calf compliance to be increased in the diseased group limbs. Comments: Here the authors are studying venous compliance as opposed to tissue compliance; they are measuring blood volume changes under various conditions. The tissues of these patients commonly become indurated and pigmented before they become ulcerated. We have had some difficulty in reproducibly measuring tissue "stiffness" with an ophthalmology glaucoma meter. Therapy with the Circulator Boot commonly softens the leg of patients with stasis disease. These authors have Circulator Boots. Hopefully, they may tell us what treatment does to their compliance measurements.

• Sahli D, Eliasson B, Svensson M, Blohme G et al.: Assessment of toe blood pressure is an effective screening method to identify diabetes patients with lower extremity arterial disease. Angiology 55:641-51, 2004. The authors evaluated a screening program for lower extremity arterial disease (LEAD) in diabetic patients and focused on the value of toe blood pressure assessment. They recruited 437 subjects, ages 30-70 years (134 healthy controls, 166 type 1 and 137 type 2 diabetic patients; control [Ctr], DM1, and DM2) with no previous history of LEAD. They were enrolled in a longitudinal study with a planned follow-up of 10 years. Patients were consecutively enrolled from outpatient diabetes units of 2 university hospitals. Subjects were screened with respect to peripheral circulation by use of established noninvasive techniques. These included arm, ankle (AP), and toe (TP) blood pressure measurements; evaluation of peripheral neuropathy; and a standardized physical examination. Results from the baseline examination are presented in this report. The number of patients who presented peripheral pressures or indices below normal (< mean -2 SD for controls) was higher among diabetic patients; 24% of DM1 and 31% of DM2, as compared to 6% of Ctr, had at least 1 lower limb with a low TP, AP, toe/arm index (TI), or ankle/arm index (AI), and these subjects were mainly identified by using the toe/arm index. TI was independently and negatively associated with fasting blood glucose in both patient groups, and with smoking, age, and diabetes duration in DM1. The mean AP was higher in the DM1 and DM2 groups compared to Ctr, whereas overall TP, TI, and AI were similar in the groups. It was also shown that abnormally low TI was significantly more common than low AI among diabetics (p<0.001), and this was true for TP vs AP as well (p<0.05). It is beneficial to include assessment of toe blood pressure and toe/arm blood pressure index to detect early LEAD in diabetic patients. Ankle blood pressure and indices alone are less efficient, owing probably to medial sclerosis in diabetic patients. Up to 30% of diabetic patients with no ischemic symptoms may have signs of impaired arterial circulation. See Stevens et al. below.

• Singhan T.M. Krishnan, MRCP, Neil R. Baker, BSC, DPODM, MCHS, Anne L. Carrington, PHD and Gerry Rayman, MD, FRCP : Comparative Roles of Microvascular and Nerve Function in Foot Ulceration in Type 2 Diabetes. Diabetes Care 27:1343-1348, 2004. OBJECTIVE-To determine the relative roles of different modalities of sensory nerve function (large and small fiber) and the role of microvascular dysfunction in foot ulceration in type 2 diabetic subjects. RESEARCH DESIGN AND METHODS-A total of 20 control subjects and 18 type 2 diabetic subjects with foot ulceration and 20 without were studied. None of the subjects had clinical features of peripheral vascular disease. The Computer-Aided Sensory Evaluator IV (CASE IV) was used to determine vibration detection threshold (VDT), cold detection threshold (CDT), warm detection threshold (WDT), and heat pain onset threshold (HPO). Vibration perception threshold (VPT) was also assessed by a neurothesiometer. Microvascular function (maximum hyperemia to skin heating to 44°C) was assessed using laser Doppler flowmetry (mean maximum hyperemia using laser Doppler flowmeter [LDFmax]), laser Doppler imaging (mean maximum hyperemia using laser Doppler imager [LDImax]), and skin oxygenation with transcutaneous oxygen tension (TcpO2). RESULTS-VPT, VDT, CDT, and HPO were all significantly higher in individuals with ulceration than in those without (VPT and VDT: P < 0.0001) (CDT and HPO: P = 0.01). LDFmax, LDImax, and TcpO2 were significantly lower in the two diabetic groups than in the control subjects, but there was no difference between individuals with and without ulceration. Univariate logistic regression analysis revealed similar odds ratios for foot ulceration for VDT, CDT, HPO, and VPT (OR 1.97 [95% CI 1.30-2.98], 1.58 [1.20-2.08], 2.30 [1.21-4.37], and 1.24 [1.08-1.42], respectively). None of the microvascular parameters yielded significant odds ratios for ulceration.CONCLUSIONS-This study found that there was no additional value in measuring small-fiber function with the CASE IV over measuring vibration by either CASE IV or the inexpensive neurothesiometer in discriminating between individuals with and without ulceration. Furthermore, none of the tests of microvascular function including the TcpO2 were able to discriminate between individuals with and without ulceration, suggesting that such tests may not be of benefit in identifying subjects at greater risk of foot ulceration. Comments: This article does not show that ischemia has no role in diabetic foot ulcers. It shows that when arterial insufficiency is mild and clinical signs of ischemia are absent, quantification of the degree of mild ischemia is not helpful.

• Siegel ME et al: Perfusion of ischemic ulcers of the extremity. Arch. Surg. 110:265, 1975. 86% chance of healing ulcer if radioactive microspheres of albumen concentrate in ulcer bed 3:1 over surrounding tissue.

• Stevens MJ, Goss DE, Foster AV, et al: Abnormal digital pressure measurements in diabetic neuropathic foot ulceration. Diabet Med 10:909-15, 1993. The diabetic neuropathic ulcer is typically slow to heal and recurrent. Macrovascular insufficiency is usually excluded as foot pulses are present and ankle:brachial pressure ratios are not decreased. These assessments cannot however exclude more distal vascular disease. Digital pressure measurements enable a reliable assessment of the distal peripheral vascular status to be made. The aim of this study was therefore to use toe pressures to assess the contribution of distal ischaemia in the pathogenesis of the neuropathic ulcer. Sixteen diabetic patients with recurrent neuropathic foot ulceration had their toe pressures compared to 10 neuropathic patients without a history of foot ulceration, 10 diabetic control subjects, and 11 normal subjects. Four non-diabetic patients with neuropathy and foot ulceration were also assessed. All subjects had ankle:brachial pressure indices > or = 1. Toe pressure was assessed using laser Doppler flowmetry to record the return of skin blood flow. The toe:brachial pressure index (TBI) was then calculated. The diabetic patients with a history of recurrent neuropathic ulceration, had the lowest mean TBI, 0.63 +/- 0.14 (SD), compared to the non-ulcerated diabetic neuropathy patients, the diabetic control subjects, and the normal subjects. 0.84 +/- 0.11, 0.82 +/- 0.1, and 0.81 +/- 0.07, p < 0.01, respectively. Three of the four non-diabetic patients with neuropathic foot ulceration also had an abnormally low TBI. Reduced toe pressure measurements are thus found to be associated with neuropathic foot ulceration. The contribution of distal ischaemia in the pathogenesis of the diabetic neuropathic foot ulcer needs to be evaluated.

• Szuba A, Oka RK, Harada R, Cooke JP: Limb hemodynamics are not predictive of functional capacity in patients with PAD. Vasc Med 11:155-63, 2006. To the practicing clinician, it seems obvious that limb hemodynamics would be the primary determinant of walking distance. However, other determinants, such as skeletal muscle metabolism, may play a role. Accordingly, in the current study, we examined the relationship between measures of limb hemodynamics and walking capacity in patients with peripheral arterial disease (PAD). We measured toe and ankle pressures for calculation of toe- (TBI) and ankle (ABI)-brachial indices; basal and hyperemic calf blood flow (CBF; by plethysmography); and initial (ICT) and absolute (ACT) claudication time using the Skinner-Gardner protocol. As expected, PAD patients had impaired limb hemodynamics with reduced TBI, ABI and a reduction in ABI post-exercise. However, there was no relationship between any of the hemodynamic variables (including ABI, ABI reduction post-exercise, TBI, baseline or maximal CBF) and walking distance as assessed by ICT or ACT. A subset of PAD patients with an ACT >750s (n = 16; 'long claudicators') were compared with a subset of PAD patients with an ACT <260s (n = 16; 'short claudicators'). The average ACT in the long claudicants was over fivefold greater than the short claudicators. Surprisingly, there were no differences between the two groups in any of the hemodynamic variables. There was also no relationship between the initial ABI, TBI, toe pressure, baseline or hyperemic CBF, and the improvement in ACT over the 3-month course of the study. This study found little relationship between hemodynamic variables and functional capacity in PAD. Accordingly, to assess the response to therapeutic interventions, exercise performance and functional status need to be directly measured, and cannot be predicted from hemodynamic measurements.

• Vogelberg KH, Muhl MA and Kohler M: Doppler ultrasound determination of maximal blood flow velocity in the diagnosis of peripheral arterial occlusive diseases in diabetes mellitus. Klin Wohenschr 65:713-718, 1987. Systolic BP remains higher in diabetics than nondiabetics in all stages of PVD. Conclude that peak Doppler velocity a better prognostic indicator of PVD than measurement of systolic blood pressure in the feet.

• Wagner WH, Keagy BA, Kotb MM et al: Noninvasive determination of healing of major lower extremity amputation: the continued role of clinical judgment. J Vasc Surg 8:703-10, 1988. Various tests are used preoperatively to differentiate patients who require an above-knee amputation (AKA) from those whose vascular supply is adequate to heal a below-knee procedure (BKA). This 15-month study of 109 amputations compared four of these methods: segmental Doppler systolic pressure measurements, transcutaneous oxygen measurement (tcPO2), fluorescein angiography, and skin thermometry. There were 66 BKAs (85% healed primarily) and 43 AKAs (93% healed primarily). The actual level of amputation was determined by the operating surgeon without consideration of the preoperative test results, and the incidence of healing was then related to the test parameters. The average skin temperature at the amputation site was higher (93.7 degrees F) in the group that healed primarily compared with those who required operative stump revision (89.9 degrees F) (p less than 0.001). The mean midcalf tcPO2 was also higher in the BKA group that healed (PO2 = 36.6 mm Hg) compared with those who failed (PO2 = 16.4 mm Hg) (p less than 0.001). Qualitative skin fluorescence was less successful in differentiating success from failure. Of the 63 BKAs that fluorescein predicted would heal, eight failed (13%). Doppler pressures at the thigh, popliteal, midcalf, or ankle level were unreliable in predicting healing of a BKA. Formulation of indexes relating absolute pressures to the brachial systolic pressure did not improve the value of this examination. From this review it is concluded that the skin temperature and tcPO2 obtained at the site of proposed amputation were the most reliable prognostic noninvasive examinations. Comments: Any test is as reliable as the technique with which it is practiced. Skin temperature can be altered by many environmental factors: sunlight through a window baking the skin, blankets, air conditioning, recent baths and close proximity of a normal leg. A temperature monitor is much superior to the hand of an examiner which may be cold (winter) or hot (summer or recent handwashing). The significance of temperature is much improved if taken following a protocol like that of Horwitz above.

• Walewski J, Taton J, Kuczerowski R, et al: Microcirculatory evaluation of the early diabetic foot syndrome using laser doppler. Pol Merkuriusz Lek 2:18-20, 1997. Recognition of early microcirculatory disturbances in feet of diabetics may facilitate the pathogenic interpretation of the diabetic foot syndrome, selection of the patients at risk of developing clinical problems and serve as the base for designing the preventive measures. This could be particularly true in diabetics with peripheral neuropathy. Therefore the study aimed at the assessment of functional parameters of the foot microcirculation in IDDM patients presenting signs of peripheral neuropathy but without any symptoms of the diabetic foot syndrome was undertaken. For comparison 20 IDDM subjects with the signs of peripheral neuropathy and 10 IDDM subjects without this complication were studied both clinically and metabolically. All of them underwent the examination of microcirculation of the feet with the use of Laser Doppler Flowmeter. The parameters measured were: resting blood flow, post-occlusive, hyperemic response, flow change after heating to 44 degrees C and the flow on dependency. In IDDM subjects with peripheral neuropathy the following functional microcirculatory abnormalities were found: delay and decrease in post-occlusive, hyperemic response (4.5 +/- 1.8 s in neuropathic vs 0.5 +/- 2.4 s in non-neuropathic IDDM patients), decrease of the peak flow (36 +/- 7.0 PU in non neuropathic vs 18 +/- 5.0 PU in neuropathic IDDM patients) and also impairment of the response of the skin flow to focal heating peak flow at 44 degrees C (48 +/- 7.0 PU vs 12 +/- 3.0 PU in non neuropathic IDDM patients). Also the venoarteriolar reflex measured as the ratio of resting to standing flow in the feet skin was significantly decreased (80% in non-neuropathic versus 35% in neuropathic IDDM patients). Conclusion: Laser Doppler Flowmetry discovers the very early functional abnormalities in the microcirculation of the skin in the feet of IDDM with peripheral neuropathy, when none of the typical symptoms of the diabetic foot syndrome is present. It points to the significance of the relation between neuropathic and microcirculatory disturbances in the early pathogenesis of diabetic foot syndrome.

• Weatherley BD, Chambless LE, Heiss G, Catellier DJ, Ellison CR: The reliability of the ankle-brachial index in the Atherosclerosis Risk in Communities (ARIC) study and the NHLBI Family Heart Study (FHS). BMC Cardiovasc Disord 6:7, 2006. BACKGROUND: A low ankle-brachial index (ABI) is associated with increased risk of coronary heart disease, stroke, and death. Regression model parameter estimates may be biased due to measurement error when the ABI is included as a predictor in regression models, but may be corrected if the reliability coefficient, R, is known. The R for the ABI computed from DINAMAP readings of the ankle and brachial SBP is not known. METHODS: A total of 119 participants in both the Atherosclerosis Risk in Communities (ARIC) study and the NHLBI Family Heart Study (FHS) had repeat ABIs taken within 1 year, using a common protocol, automated oscillometric blood pressure measurement devices, and technician pool. RESULTS: The estimated reliability coefficient for the ankle systolic blood pressure (SBP) was 0.68 (95% CI: 0.57, 0.77) and for the brachial SBP was 0.74 (95% CI: 0.62, 0.83). The reliability for the ABI based on single ankle and arm SBPs was 0.61 (95% CI: 0.50, 0.70) and the reliability of the ABI computed as the ratio of the average of two ankle SBPs to two arm SBPs was estimated from simulated data as 0.70. CONCLUSION: These reliability estimates may be used to obtain unbiased parameter estimates if the ABI is included in regression models. Our results suggest the need for repeated measures of the ABI in clinical practice, preferably within visits and also over time, before diagnosing peripheral artery disease and before making therapeutic decisions.

• Wigington G, Ngo B, Rendell M: Skin blood flow in diabetic dermopathy. Arch Dermatol. 140:1248-50, 2004. BACKGROUND: Diabetic dermopathy has been termed the most common cutaneous finding in diabetes, occurring in as many as 40% of diabetic patients older than 50 years. Using laser Doppler technology, we tested the hypothesis that dermopathy lesions represented areas of cutaneous ischemia. DESIGN: A survey of cutaneous blood flow in diabetic patients with dermopathy and comparison of values with those in nondiabetic patients. SETTING: Outpatient clinic specializing in diabetes. PATIENTS: A consecutive sample of 61 diabetic patients (52 men and 9 women; mean +/- SEM age, 58 +/- 2 years) with dermopathy had blood flow measurements performed at the sites of dermopathy and at contiguous uninvolved sites. Flow values were also determined at several reference sites and compared with those in 41 nondiabetic control subjects (30 men and 11 women; mean age, 53 +/- 3 years). RESULTS: Heat-stimulated blood flow values at the knee, ankle, and toe were about 50% lower for the dermopathy patients than for the nondiabetic controls. Yet, despite their reduced skin blood flow reserve, the dermopathy lesions did not show relative ischemia. At the basal temperature of 35 degrees C, flow was 1.1 +/- 0.1 mL /min per 100 g of tissue in apparently normal skin vs 2.2 +/- 0.2 at dermopathy sites; at 44 degrees C, flow at the normal sites was 7.9 +/- 0.3 mL /min per 100 g of tissue vs 12.9 +/- 0.6 at dermopathy sites (P<.01 for both comparisons). CONCLUSIONS: Although patients with diabetic dermopathy exhibited reduced skin blood flow compared with nondiabetic volunteers, flow levels were considerably higher at the dermopathy sites than at contiguous uninvolved skin sites. These results refute the hypothesis that diabetic dermopathy represents local ischemia. However, it is still possible that the scarring represented by dermopathy lesions is related to decreased skin perfusion due to diabetes. Comments: As the laser Doppler detects flow in both nutritient arterioles and A/V shunts, it is quite possible that the dermopathy areas may represent areas with increased neuropathy, increased shunting and decreased arteriolar blood flow.

• Williams PG, Montgonery H and Horowitz O: Oxygen tension of tissues by the polarographic method. VI. Effect of changes in position on oxygen tension of the skin of the toes. J Clin Invest 32:1097,1953. Tilting the bed into 10 degrees reverse Trendelenburg maximizes blood flow to the toes. Raising the foot decreases it.

• Williams, Robert: PW217 - Periwound TCOM Used to Assess Response of Chronic Critical Limb Ischemia to Novel Pneumatic Intermittent Compression Device Timed with Cardiac Relaxation. Poster at Third Congress World Union of Wound Healing Societies. Toronto, June 2008. Goals and Objectives: Periwound trascutaneous oximetry (TCOM) has prognostic value in predicting healing of wounds associated with peripheral artery disease (PAD). Does a novel pneumatic device used to deliver intermittent compression therapy (ICT) used to treat wounds associated with PAD alter periwound TCOM values? Purpose: Assess trascutaneous oximetry (TCOM) response in periwound tissue of ischemic wounds to novel ICT timed with cardiac relaxation. Methods: Eight patients with documented PAD with lower extremity wounds clinically appearing ischemic that failed conventional therapy were selected. Periwound TCOM values were assessed with limb supine while breathing room air (RA) and then 100% oxygen (O2). TCOM values were obtained prior to initiating intermittent compression therapy (ICT) and reassessed every 4-6 weeks during compression therapy. ICT consisted of 45 mm Hg compression applied to the affected lower limb during cardiac diastole for 0.40 to 0.45 seconds at a time for 40 min a day, 3-5 days a week. Results: Patients reported significant decrease in pain associated with wound. TCOM responses to ICT timed with diastole were categorized as follows: 1. Improved TCOM with both RA and O2- correlated with wounds that improved or closed. 2. Improved TCOM with O2 only- correlated with wounds that stabilized or improved. The noted change in O2 response suggests the detection of early changes in microcirculation resulting from ICT. 3. Worsened TCOM values- correlated with wounds that remained stable and did not worsen despite modest decreases in TCOM values. Discussion / Conclusion: TCOM demonstrated enhanced periwound blood flow in patients responding to ICT timed with cardiac relaxation. TCOM findings also suggest that a subgroup of patients with initial response in microcirculation may benefit from continued ICT. There was no harm detected clinically in the subgroup with declining TCOM values, but this response may be predictive of patients likely to not respond to ICT. Comments: These difficult patients were pumped three times a week. In contrast, the difficult patients shown in our patient history section may have been pumped up to four times a day during the initial phases of their therapy. Those initially treated as an outpatient commonly were treated twice daily. Both inpatient and outpatient groups were treated vigorously until their wounds were obviously turned around and a favorable prognosis appeared certain. It is pleasing to find that less aggressive therapy may help many patients.

• Wutschert R and Bounameaux H: Determination of amputation level in ischemic limbs. Reappraisal of the measurement of TcPO2 . Diabetes Care 20:1315-1318, 1997. Author's conclusions: Preoperative TcPO2 measurement may be of considerable help to predict stump outcome and level of amputation. Our study provides objective prognostic values for the range 0-50 mmHg and suggests that TcPO2 should usually be 20 mmHG at the site of amputation, which will predict healing with 80% accuracy and should, therefore, not be used as a sole criterion. Despite this aid in making his decision about amputation level, the surgeon still has to balance between his goal of achieving primary wound healing and his hope of preserving maximal limb length and has to consider patient preferences.

• Young JL, Pendergast DR and Steinbach J: Oxygen transport and peripheral microcirculation in long-term diabetes (43164). P.S.E.B.M. 196:61-68, 1991. Measured muscle blood flow by 133Xe clearance and O2 transport during exercise. 12 male insulin-treated diabetics for ten years had decreased muscle blood flow, O2 transport and exercise tolerance while having no macrovascular disease.