Faculty Bibliography

To determine systemic and local risk factors that contribute to limb loss despite a patent infra-inguinal bypass graft and how to prevent it, we reviewed 987 patients who underwent infra-inguinal bypasses at our institution. Seventy-five (7.6%) patent grafts failed to achieve a healed foot despite exhaustive attempts to do so and these patients underwent major amputation either above the knee (AKA) or below the knee (BKA). In 525 femoro-popliteal bypasses, there were 38 major amputations (29 BKA; 9 AKA) with a patent graft; in 462 femoro-distal bypasses, there were 37 amputations (22 BKA; 15 AKA) with a patent graft. The remaining 912 patients with limb salvage as well as all the patients with limb loss were evaluated with regard to systemic risk factors, quality of the run-off from the popliteal artery, continuity of the tibial artery into the arch as demonstrated on arteriography, the haemodynamic improvement obtained postoperatively, and the presence and extent of necrosis in the foot. The presence of diabetes, extensive pedal necrosis and advanced infection predispose to limb loss despite a patent lower extremity bypass graft. Patients who lost their limbs despite a functioning bypass to an isolated popliteal segment had significantly less pronounced haemodynamic improvement postoperatively. An early graft extension to a reconstituted tibial or peroneal artery or a direct bypass to a distal tibial or peroneal artery may reduce the incidence of limb loss in this setting. When a patent bypass to an isolated tibial or peroneal artery segment failed to relieve foot ischaemia, limb salvage was achieved by a distal extension to plantar arteries

Bilateral 6 mm PTFE grafts were placed from the external iliac artery to the femoral artery with ligation of the intervening segment of the iliofemoral artery in 14 dogs. An arteriovenous fistula was constructed at the distal anastomosis on one randomly selected side in each animal while the contralateral graft served as a control. Graft follow-up ranged between 8 and 12 months in all animals. Serial arteriography was performed to confirm graft and fistula patency and demonstrated persistence of antegrade flow into the arterial tree distal to all patent bypasses. Femoral intraarterial pressures distal to patent grafts were identical on both sides in each animal throughout the study. Cumulative life-table patency rates showed higher patency for the arteriovenous fistula bypasses than the control grafts at all time intervals: 71% vs. 57% at 3 months, 48% vs. 25% at 6 months, and 40% vs. 22% at 12 months, respectively. This is the first controlled study that provides experimental evidence suggesting that these bypasses may produce increased patency of prosthetic arterial grafts and lends support to their use in a clinical, prospective, randomized study

Eight patients with severe pedal ischemia in the presence of palpable foot pulses are described. All had atherosclerosis, and seven patients also had diabetes. There were two anatomic patterns of disease, including supramalleolar obstruction with reconstitution of pulsatile flow in three patients and segmental occlusion of the pedal vessels in five. All patients underwent arterial reconstructive surgery. Patency was sustained in six patients, with limb salvage in five and below-knee amputation in one patient for persistent necrosis and infection of an open amputation. Of the two eventual bypass failures, a transmetatarsal amputation continued to heal in one patient, and the other required amputation below the knee. Palpable pedal pulses and satisfactory ankle/brachial indexes did not rule out the presence of surgically correctable distal arterial occlusive disease. Therefore arteriography is indicated in any patient with persistent forefoot ischemia that fails to respond to conservative measures. The safety and patency of the distal reconstructive procedures performed in this series suggest that salvage of weight-bearing tissue and rapid healing, as well as limb salvage, are legitimate indications for revascularization

In patients with aortoiliac occlusive disease interruption of critical collaterals during another nonvascular or cardiac operation may threaten limb viability. This occurred in four patients whose limb-threatening ischemia was precipitated by radical cystectomy with bilateral hypogastric artery ligation, left colon resection, or coronary artery revascularizations by means of the internal mammary artery. Important collateral pathways, the interruption of which may account for this phenomenon, are detailed, and approaches are outlined for prevention and management of acute ischemia in this setting

We have treated 30 patients requiring urgent or emergent vascular procedures in the first 6 weeks after a myocardial infarction (median 11 days) from 1977 through 1989. Forty operations were performed, including 28 lower extremity revascularizations, 10 major amputations and revisions, and two carotid endarterectomies. There were four postoperative deaths (three cardiac related) and two nonfatal reinfarctions. Cardiac complications did not correlate with age, interval from myocardial infarction to surgery within the initial 6 weeks, type of anesthesia, or complexity of operation. Twenty of 24 patients survived attempts at leg revascularization, with ultimate limb salvage in 16. Our cardiac complication rate of 17% (5/30 patients) was reasonably close to that predicted by the Goldman risk scale for classes II and III and significantly better than class IV and also better than that predicted by the Cooperman risk scale for vascular surgery, despite the more recent preoperative myocardial infarctions in our patients. We attribute our low morbidity and mortality to the extracavitary nature of the procedures and possibly to improvements in anesthetic and perioperative management. Patients requiring urgent revascularization for limb salvage should not be denied surgery on the basis of a recent myocardial infarction

The value of HLA matching in cadaver renal transplantation (CRT) continues to be debated. It has recently been suggested that increased importance be given to HLA matching for the distribution of cadaver kidneys. Such a policy would add both delay and expense to CRT, which could be justified only by significantly improved results. The results of CRT in 252 cyclosporine treated adult patients transplanted at our institution from November 1984 to April 1989 were reviewed. Kidneys were initially transplanted into crossmatch-negative recipients based on waiting time, regardless of match. From October 1987, a points system, based on United Network for Organ Sharing (UNOS) criteria has been used. Eighty-four pts. with zero antigen match with their donors were compared with 168 pts. sharing 1-6 Ag. Actuarial graft and patient survival were determined by the cumulative life table method and compared using a log rank test. Our results indicated no statistically significant difference in graft survival because of better matching or mismatching. These findings are in keeping with our previously reported long-term results for non-CsA pts. Past predictions of improved graft survival based upon better matching at our institution have not fulfilled expectations, with the exception of 6 Ag matches. In conclusion, increased emphasis on HLA matching with fewer 'points' for poorer matches does not appear justifiable

We reviewed 239 infrapopliteal reversed greater saphenous vein graft bypasses placed for critical ischemia over a 7-year period to determine the influence of vein diameter on graft patency and limb salvage. Grafts were assigned to four groups based on the minimum external diameter measured during operation: less than 3.0 mm, n = 18; 3.0 mm, n = 59; 3.5 mm, n = 67; and greater than or equal to 4.0 mm, n = 145. A pattern of increasing graft patency and limb salvage among the four groups was noted as the minimum external diameter increased from less than 3.0 mm to greater than or equal to 4.0 mm. When compared to the larger grafts greater than or equal to 4.0 mm, primary graft patency was significantly lower both for less than 3.0 mm grafts (0% for less than 3.0 mm vs 65% for greater than or equal to 4.0 mm at 3 years, p less than 0.001) and for long (greater than 45 cm) 3.0 mm grafts (38% for long 3.0 mm vs 75% for greater than or equal to 4.0 mm at 2 years, p less than 0.005). All 3.5 mm and short (less than 45 cm) 3.0 mm grafts had patency rates similar to greater than or equal to 4.0 mm veins. Thus long 3.0 mm and all less than 3.0 mm reversed saphenous vein grafts should be considered at high risk for failure. Veins with fibrotic, thick-walled segments identified during operation (n = 19) had patency rates significantly lower than nonfibrotic veins (n = 270; p less than 0.01), and this may play a role in the failure of some less than 3.0 mm minimum external diameter vein grafts

Routine arteriography of the axillary, subclavian, and innominate arteries before axillofemoral bypass surgery has not been advocated because of the presumed rarity of stenosis of these inflow vessels. However, we have noted in this patient population with extensive atherosclerosis that inflow disease can cause axillofemoral graft failure despite normal preoperative clinical and noninvasive parameters. We prospectively determined the incidence of unsuspected inflow stenosis with arteriography in 40 consecutive candidates for primary (28) or secondary (12) axillofemoral bypass surgery. A new arteriographic technique with a single translumbar puncture was developed to safely and clearly visualize the potential inflow and outflow tracts. Ten of the 40 patients (25%) exhibited inflow stenosis greater than 50% of luminal diameter (unilateral in eight patients and bilateral in two patients). Seven were on the left side (five subclavian, two axillary) and five were on the right side (three subclavian, one axillary, one innominate). In eight of the 40 patients (20%) the stenotic inflow lesion was ipsilateral to the ischemic leg and therefore proximal to the preferred inflow site of an axillofemoral bypass. Upper extremity arterial pressure measurements suggested potential inflow artery stenosis in only three of the 12 (25%) instances. These findings show that equal arterial pressures in the upper extremities do not ensure adequate inflow for an axillofemoral graft. Routine arteriographic assessment of inflow intacts is recommended before axillofemoral bypass surgery