| Authors (Years) |
Preoperative Screening Methods or Purpose of Study |
Number of Patients |
Surgically correctable CAD |
Clinically suspicious CAD |
No Symptoms of CAD |
cardiac procedures, overall mortality & postop. events |
|
Coronary angiograms |
Elective PVD:
263 aortic aneurysms,
295 carotids,
381 infrainguinal |
31%, 26%, 21% |
44%, 33%, 30% |
18%, 17%, 8% |
30%, 22%, 19%, mortality 5.3% |
|
Thallium Dipyridamole scans |
50 stable patients with ? CAD and severe PVD |
16 had redistribution defects |
32 normal or fixed defect |
- |
6 of 16 had coronary angiograms & 4 CABGs;
8 of 16 had cardiovascular events postop. |
|
EKG Monitoring |
176 PVD patients for elective surgery |
32 or 18% had 75 ischemic RST depression episodes |
- |
73/75 ischemic episodes asymptomatic |
1 fatal MI, 3 nonfatal MI's, 4 unstable angina & 5 ischemic CHF. 1 postop event among the 144 with no preop. ischemia. |
|
Dipyridamole-thallium imaging and 5 clinical scoring systems |
66 patients with limited exercise tolerance |
21 pts with reversible defects & 6 more with reversible defects had angiography showing severe CAD or cardiomyopathy - |
- |
30 had normal scans |
9 of the 21 had all of the postoperative events. Scans positive in all patients having events. Clinical symptoms no predictive help. |
|
Prospective, randomized clinical trial optimizing preop. cardiovascular hemodynamics |
89 patients for limb-salvage surgery |
- |
- |
- |
Overall mortality 3.4% in Tuneup group and 9.5% in controls |
|
Continuous ambulatory ECG monitoring preop. Serial EKG's and CPK's postop. |
24 patients for aorta and 72 for infrainguinal surgery |
Monitoring showed ischemia in 9 of 96 patients (9.4%) |
7.4% had new rhythm abnormalities: 2 ventricular tachycardia and 5 atrial flutter/fibrillation. |
87 had normal preop. monitoring. |
1 of the 9 had a postop infarction. 14 of the 87 normals had postop infarctions and 6 died. |
|
Reported by method of anesthesia for femoral to distal bypass surgery |
133 pts general anesthesia, 144 epidural and 136 spinal |
- |
- |
- |
Cardiac events or death: general 16.7%, Epidural 21.3% & spinal 15.4%. Differences insignificant |
|
Reporting Perioperative myocardial infarction in peripheral vascular
surgery. |
191 patients & 204 operations: 100 elective, 70 urgent & 34 emergency |
120 pts of 182 with data had preop ischemic events |
- |
- |
Myocardial infarction and death overall 7.3%; 6% for elective and urgent pts and 12% for emergency pts. 30% of infarctions silent and 50% fatal (8 cardiac deaths). |
| de Virgilio et al. (1996) |
|
Dipyridamole sestamibi scan and Eagle scoring: 1 point each for age >70, diabetes, Q-waves, angina, history of ventricular ectopy. |
70 pts with 0.8 Eagle score not scanned; 31 with Eagle 1.1 & 8 with Eagle 1.6 scanned |
For the 31: 7 reversible defects; the 8 had CABG or angioplasty. |
Of the 31, 10 fixed defects. |
Of the 31, 14 normal scans |
Overall 4 perioperative infarctions (2.8%), 7 cardiac events (4.8%) & 1 cardiac death (0.7%). Of the 8, all had unstable angina and 2 had infarctions. 3 cardiac events in pts with normal scans or fixed defects. |
|
Deleterious outcomes of extensive, comprehensive cardiac evaluation and intervention before planned vascular surgery. |
161 pts scheduled for major vascular surgery. Eight patients (19%: one with cerebrovascular disease, and seven with aortic aneurysms) eventually refused vascular surgery after extended cardiac workup. |
42 get extended cardiac evaluation: 43% ECHO or radionuclide ventriculography, 52% dipyridamole thallium scintigraphy, 64% Coronary cath, 21% PTCA & 17% CABG. Median elapsed time 14 days. Median time from workup to vascular surgery 25 days. |
- |
- |
16/42 had untoward events associated with their evaluation. Complications attributed to coronary cath, PTCA & CABG included prosthetic graft infection, pseudoaneurysm(2), sternal wound(2), renal failure & brain anoxia. Two leg amputations resulted from delays. |
|
No preop screening. Continuous 12-lead ST-trend monitoring 48 h to 72 h after surgery & cardiac troponin-I measured first three postop days. |
185 patients undergoing vascular surgery |
- |
- |
- |
36 pts(20.5%) had 66 iscchemic events, 12 had PMI's (1 death) occurring after an average of 226+/-64 minutes of ischemia. Pts with an average of 36+/-26 minutes ischemia had no infarctions. |
|
Patients randomized to have CABG (41%), angioplasty (59%) or no procedure prior to vascular surgery |
510 VA patients, 33% abdominal aneurysms & 67% PAD |
- |
- |
- |
Postop MI's in 12% of the cardiac surgery gp & 14% of controls. Mortality rates of 22% and 23% respectively at 2.7 years. Cardiac gp delayed 54 days to PVD surgery. |
|
Evaluate prognostic role of pre-operative stratification by ACC/AHA guidelines, the timing of adverse outcomes and predictive role of troponin. |
391 patients prospectively into three groups: (1) with coronary revascularization in the past 5 years,
(2) with intermediate clinical risk predictors, and (3) with minor or no clinical risk predictors. |
- |
- |
- |
Compared to gp 3, gp 1 had 5.21 hazard ratio and gp two 2.58 hazard ratio. Overall, by 18 mos, 18.7% had died or had acute MI. Most events occurred by 30 days. Troponin elevations frequent & independently associated with increased risk. |
|
Retrospective study of benefit of statin and beta-blocker use on postoperative morbidity and mortality. |
446 infrainguinal vascular operations |
- |
- |
- |
30 day postop:statin Rx associated with an overall decrease in CV complications (6.9 vs 20.1%) and shorter length of stays. 48% overall death rate at 5.5 years with longer survivals in statin gp. |
In previous Newsletters, Medicare data was shown documenting a persisting and perhaps increasing problem with leg amputations among diabetics in spite of the talent and efforts of many. The problem may be likened to street crews plowing the main roads during a snow storm that does not cease; people cannot get around if their side road is not cleared also (or worse, if the plow impacts snow at the head of their road or driveway) and continuing snowfall means the road crews work is never done. In contrast to the invasive procedures, Circulator Boot therapy stimulates blood flow and endothelial factors throughout the entire leg while supporting the general circulation. Still, only when the spring comes (when the metabolic abnormalities are controlled) will a lasting cure be possible.
The skillful vascular surgeon generally takes his/her patient
through complex procedures safely and effectively. But problems with age, debilities and metabolic abnormalities persist. Yes, technical problems may occur also. Rarely, for example, a saphenous vein may be
harvested for bypass without ascertaining there are other venous outflow routes in the leg. If the deep vein system has
been compromised by thrombophlebitis, removal of the superficial veins can be catastrophic. During the bypass procedure,
bleeders and communicating vessels are frequently tied off. Occasionally, lymph channels can also be ligated leading to
severe postoperative lymphedema. Especially on lateral views of an arteriogram of the lower leg, the identity of the three
tibial arteries can be confused and a bypass inserted into the wrong vessel, e.g. one without any runoff. On rare occasion,
our surgeons have not been able to complete a bypass because the target distal vessel was too calcified to allow sewing.
Healing of the anastomosis sites may be compromised by infection and especially distally by stasis disease. Infected
sutures may fail and life-threatening hemorrhage occur. If runoff is not sufficient, the bypass may thrombose. When the
bypass is successful, a non-innervated conduit is commonly provided from the groin to the distal leg with the result that
(a) blood flow distal to the proximal anastomosis is diminished occasionally sufficiently to produce ischemic symptoms in
the thigh muscles and calf; (b) a male patient loses the capacity to stiffen his legs and diminsh blood flow down the legs
worsening his tendency to erectile dysfunction; and (c) blood pressure regulation is lost over the distance of the bypass
so that the pressure head at the ankle is increased by the length of the bypass in the erect position; and (d) the arterial
pressure gradient down the leg is disturbed: high pressure at the groin may push blood towards the knee while even higher
pressure in the erect position at a distal anastomosis may push blood backwards up the leg again toward the knee where the
pressures may oppose one another cancelling flow through the larger channels but supplying the small vessels where flow is
regulated by tissue needs. Slow flow may promote thrombotic events. The integrity of the distal leg may become dependent
on the patency of the bypass which in turn may be affected by the skill of the surgeon in placing the bypass and the habits
of the patient in not stopping flow in the bypass by leg-crossing in a chair or while sleeping. We have had patients
referred for boot therapy who were noted to have or hypothesized to have all of these problems. Perhaps, related to such factors
were the results of Morris et al. In doing repeated arteriograms in patients with with bilateral arteriosclerosis but an
unilateral bypass, they have performed perhaps the only controlled study of the bypass procedure. Repeat angiograms were
done on 42 patients with ASO. Occlusive disease progressed significantly faster in operated limbs (77%) than in
nonoperated limbs (44%). When progression occurred, it was more likely to take the form of occlusion in operated limbs (85%)
than in nonoperated limbs (61%). Graft closure was associated with a 93% incidence of disease progression, but even limbs
with patent grafts had a more rapid progression than nonoperated limbs (62 vs 44%). There was good correlation between
symptoms and the angiographic process.
The incidence of stroke following cardiovascular surgery was not discussed above. Stamou reports a range of 0.8-5.2%. Stroke following peripheral vascular surgery is uncommon (Axelrod et al). In the latter situation it is associated with a history of previous stroke and a greater degree of illness. When it does occur, it greatly increases mortality and hospital length of stay.
Peripheral vascular and cardiovascular procedures pose greater risks.
The literature quoted above clearly shows much remains to be done. Good pre-operative care and preparation is helpful, but need not include cardiac revascularization procedures in stable patients. Indeed, long term mortality may not be improved by cardiac revascularization procedures prior to peripheral vascular surgery (McFall et al above) and may entail delays and complications of their own (Krupski et al above). Treatment with statins is worth considering.
