Perspectives in Circulation Today

Primo Non Nocere

Femoral Arteriography, A Needed (?) Road Map for Needed (?) Invasive Vascular Procedures

Indications, Risks and Alternative Imaging

http://circulatorboot.com/casehistory/case200e.html

This 72 year old man had hypertension, hyperlipidemia and ten blue toes since his heart catheterization procedure in April 1999. He had coronary bypass surgery with the use of a saphenous vein in August 1999. His toe pain persisted and the skin began to break down. When referred for boot therapy in September 1999, he had no distal pulses and the PPG waveforms in his feet were flat. His pain was relieved and his foot lesions healed with Mini-Boot therapy. He was thought to have had cholesterol emboli dating back to his first femoral catheterization procedure. His foot problem was largely ignored in hopes it would spontaneously resolve. Indeed, of the 25 legs reported on our website, the embolization problem was initially ignored in most. Embolization is commonly not mentioned as a potential complication of arteriography as noted below.

Arteriography

Indications for arteriography:

Atherosclerotic vascular disease, including:
	Aneurysms
	Emboli
	Occlusive disease
	Thrombosis
Vascular trauma
Preoperative planning and postoperative evaluation for reconstructive surgery
Evaluation of surgical bypass grafts and dialysis grafts and fistulas
Other primary vascular abnormalities, including:
	Vascular Malformations
	Vasculitis
	Entrapment syndromes
	Thoracic outlet syndrome
Delination and evaluation of tumors
Before interventional procedures

The Society committee then reports the rates for complications of the arteriography, finding the procedure safe and the complication rate generally under 1%:

Complication Rates for Femoral Arteriography:

For puncture site complications:
	Hematoma (requiring transfusion, surgery, or delayed discharge) ...0.0-0.76%
	Occlusion 0.0-0.76%
	Pseudoaneurysm/arteriovenous fistula 0.04-0.2%
	Arterial dissection/subintimal passage 0.43%
	Subintimal injection of contrast 0.0-0.44%
Catheter-induced complications (other than puncture site)such as distal emboli 0.0-0.10%;
Major contrast reactions 0.0-3.58
Contrast-media-associated nephrotoxicity 0.2-1.4%

As with surgery, the presence of diabetes or hyperglycemia alone may not constitute a risk factor. However, diabetics requring arteriography have more than diabetes alone; they may have PVD and associated coronary heart disease, congestive heart failure, hypertension, varying degrees of renal impairment and/or a history of kidney transplantations. All of the latter increase the likelihood of complications. Besides diabetes with its complications, other medical conditions may pose special risks: hyperthyroidism (storm), pheochromocytoma (hypertension crisis), sickle cell anemia (sickling) and multiple myeloma (renal failure).

Manufacturers of contrast media are careful to list the potential hazards of their product (eg January 2003 Mallinckrodt Inc). Thus, they point out that ionic iodinated contrast media inhibit blood coagulation, in vitro, more than nonionic contrast media and that serious, rarely fatal, thromboembolic events causing myocardial infarction and stroke have been reported during angiographic procedures with both ionic and nonionic contrast media. Numerous factors, including length of procedure, catheter and syringe material, underlying disease state and concomitant medications may contribute to the development of such thromboembolic events.

Lilly MP et al (Annals of Vascular Surgery 4: 264-269, 2005) reviewed the anatomic and clinical factors associated with complications of transfemoral arteriography over 4 years among their 10,589 cases. Forty-seven patients required corrective surgery. 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. 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. Thus, major complications were rare but potentially quite serious.

The question whether femoral arteriography has a relationship to postoperative groin wound infections has been examined by Amelii et al (Annals of Vascular Surgery 4: 328-332, 1990). While difficulty in performing the arteriogram and reconstruction procedures over four hours were associated with subsequent infection, there was no correlation with the site of the needle puncture or the development of a hematoma. Forty-four femoral reconstructive procedures (88 groin incisions) for aortoiliac disease were performed. Positive cultures occurred in 43.2% of patients. There were no graft infections. The authors concluded that transfemoral arteriography does not increase the risk of complications of arterial reconstruction involving a femoral anastomosis. That is not to say that they did not recognize problems: seven patients had postoperative groin wound complications (15.9%), including three lymph leaks (6.8%) and four confirmed or suspected infections (9%).

Asif et al detailed the problem of radiocontrast-induced nephropathy(Am J The. 10: 137-47, 2003). They note that radiocontrast administration remains the third leading cause of hospital-acquired acute renal failure. Clinically, they defined radiocontrast-induced nephropathy (RIN) 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. Kayani et al highlighted a dramatic reversible consequence of contrast nephrotoxicity superimposed on renal obstruction (British Journal of Radiology 78, 349-352, 2005.) They report two patients in whom 99Tcm-mercaptoacetyltriglycine was used to delineate upper urinary tract obstruction. In one case, this led to severe impairment of perfusion and uptake on the renogram and in the second case virtual non-visualization of the obstructed kidney. Subsequent treatment of obstruction led to dramatic improvement in renal function. They note that it is important for the attending physicians to be aware of the potential of contrast nephrotoxicity in obstructed kidneys and the fact that significant improvement is possible if the obstruction is removed. In some patients contrast media can be avoided with the use of CO2. Spinosa et al reported that the use of small volumes of nonionic contrast material to supplement CO2 angiography in patients with PVD and chronic renal insufficiency can be associated with a significant increased risk of worsening renal function when compared to angiography performed with CO2 alone or CO2 and gadodiamide ( an injectable, nonionic extracellular enhancing agent for magnetic resonance imaging (J Vasc Intervent Radiol 11:35-43, 2000).

Castellano et al have assessed the potential harm done to the patient due to radiation Br J Radiol 68:502-7, 1995). The assessment was made of the absorbed dose associated with femoral arteriography using a modern digital imaging system.Older systems obviously deliver more radiation. A bilateral femoral arteriogram was performed on 17 patients, 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. So yes, some radiation is delivered but considering the age and prognosis of the PVD population, the radiation detriment is reasonable. Physicians studying soldiers and younger people, however, might consider alternative imaging procedures especially if the the available equipment is old and repetitive studies are necessary.

Alternative imaging procedures have their own limitations. Landry et al, for example, found Duplex scanning alone did not provide sufficient imaging before secondary procedures after lower extremity reversed vein bypass graft (LERVG) (J Vasc Surg 29:270-80, 1999). They point out that the use of the duplex scan alone may result in missing additional lesions that are threatening patency. Indeed, comparison of the Duplex scan results compared with the results of preoperative arteriograms and the findings at operation in 119 cases (58%), 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. All frequently performed bypass graft configurations had some discrepancy between arteriographic and duplex scan findings. They concluded that arteriography is mandatory before LERVG revisions.

Ascher et al have reported their success with duplex ultrasound arterial mapping (DUAM) in lower extremity revascularization without preoperative contrast arteriography in 485 cases. Ann Vasc Surg 16:108-14, 2002. 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. 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%). 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. The authors concluded that their early experience showed 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 procedures may be needed for certain patients.

Magnetic resonance angiography continues to improve with improved software and hardware. Like contrast angiography it provides a permanent record for all to evaluate. Carpenter has reported on its success in peripheral artery disease (Hosp Practice p79-97, Oct 15, 1992). He noted that the technique was safer than contrast arteriography in which he estimated nearly 10% of patients will have minor to serious complications. Further, he maintained, in up to 70% of patients, preoperative arteriography fails to identify suitable distal vessels for bypass. Here among 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 included presence of a pacemaker, cerebral aneurysm clips or metal in the eye. In a subsequent publication the same authors noted a cost savings of $1288 for each patient treated with preoperative MRA alone (J Vasc Surg 20:861-9, 1994). A recent meta-analysis concluded that magnetic resonance angiography is highly accurate for assessment of the entire lower extremity for arterial disease and that three-dimensional Gd-enhanced MRA improves diagnostic performance compared with 2-D MRA (JAMA 285:1338-1345, 2001).

Death is, of course, the ultimate complication. A patient was referred to the Bryn Mawr Boot Clinic from a tertiary care center in Philadelphia. He had a ulcer of his big toe, an insensate foot, a palpable posterior tibial pulse and a low blood pressure in his toes. He was begun on outpatient Miniboot therapy for a neuropathic ulcer associated with distal ischemia. He began to get better. However, his family doctor believed an arteriogram should have been done at the tertiary care center or at least at Bryn Mawr. He hospitalized the patient in his community hospital specifically for the procedure. The study showed no need or possibility for reconstructive surgery and the patient was returned to his room. Two hours later he was found dead in the bathroom. The pathologist reported the cause of death as a delayed anaphylactic reaction. A rare case to be sure but one with potential legal consequences for the family doctor who ordered a test his consultants had thought to be unnecessary. Caro et al have reviewed the risks of death and severe nonfatal reactions with high- vs low- osmolality contrast media (Am J Roentg 156: 825-832, 1991). The risk of death with high-osmolality media was 0.9 per 100,000 uses (95% confidence interval, 0.3-2.6 per 100,000). The difference in risk produced by using low-osmolality media was 0 (95% confidence interval, -1.1 to 1.1 per 100,000). The risk of severe reactions associated with high-osmolality media was 157 per 100,000 uses (95% confidence interval, 144-172 per 100,000). The reduction in risk that can be obtained by the use of low-osmolality media was estimated to be 126 per 100,000 (95% confidence interval, 110-142 per 100,000). This meta-analysis shows that the risk of death is very low with either agent. The risk of serious reaction is greater with the high osmolality media but still rare; approximately 80% of them can be prevented by using low-osmolality media.

Perspectives in Circulation Today

Volume 2, Number 2