Faculty Bibliography

Techniques for exposure of the popliteal artery via lateral approaches above and below the knee are described. These techniques were used successfully in 21 patients who required secondary arterial reconstructions in the presence of extensive scarring, infection, or both in the standard medial access routes

Criteria for abandoning infrainguinal arterial reconstructions in favor of major amputations should include reliable predictors not only of graft patency, but more importantly, of limb salvage. To evaluate the efficacy of intraoperative outflow resistance measurements in predicting limb salvage after infrainguinal bypasses, we have reviewed 134 such operations (64 femoropopliteal and 70 femorodistal bypasses) performed for critical ischemia. Outflow resistance measurements were divided into quartiles for femoropopliteal bypasses (Group A 0.17 mm Hg/ml/min or less, Group B 0.18 to 0.24 mm Hg/ml/min, Group C 0.25 to 0.4 mm Hg/ml/min, and Group D greater than 0.4 mm Hg/ml/min) and femorodistal bypasses (Group A 0.4 mm Hg/ml/min or less, Group B 0.4 to 0.58 mm Hg/ml/min or less, Group C 0.6 to 1 mm Hg/ml/min, and Group D 1 mm Hg/ml/min or greater). One year limb salvage rates for patients who underwent femoropopliteal bypass were 95 percent, 92 percent, 87 percent, and 67 percent from the lowest to the highest quartile (difference not statistically significant), and for those who had femorodistal bypass, they were 51 percent, 75 percent, 48 percent, and 0, respectively (p less than 0.05). Interestingly, 12 month graft patency and limb salvage rates for patients who underwent femorodistal bypass with outflow resistances between 0.59 and 1 mm Hg/ml/min did not correlate well (22 percent and 48 percent, respectively), whereas for those with outflow resistance greater than 1 mm Hg/ml/min, they were 22 percent and 22 percent, respectively. Thus, measurement of intraoperative outflow resistance is a very accurate predictor of limb salvage after infrainguinal bypass operations

Of 724 bypasses with polytetrafluoroethylene grafts performed for critical ischemia during a 6-year period, 165 (23%) failed and necessitated reoperation for continued limb salvage. Forty-three failures occurred in 199 femoral-above-knee-popliteal bypasses (F-AKP), 33 failures in 177 femoral-below-knee-popliteal bypasses (F-BKP), 52 failures in 182 femorodistal bypasses (F-D), 28 failures in 85 axillofemoral bypasses (Ax-F), and nine failures in 81 femorofemoral bypasses (F-F). Our reoperative approach consisted of dissection of the distal anastomosis, longitudinal incision in the hood of the graft directly over the anastomosis, and proximal graft thrombectomy. Intimal hyperplasia was treated by patch angioplasty, proximal or distal progression of atherosclerosis was treated by a graft extension, and thrombectomy alone was performed when no cause of graft failure was identified. More recently, a totally new bypass was constructed in 27 cases of F-BKP or F-D failures. Reoperations featuring graft salvage for failed extra-anatomic and F-AKP bypasses yielded 3-year patency rates from the time of first reoperation of 71% and 52%, respectively, whereas for F-BKP and F-D reoperations, 3-year patency rates were 13% and 15%, respectively, at 3 years. However, totally new grafts to a different outflow artery in these settings had 3-year patency rates of 48% and 39%. These data support the aggressive use of reoperation with graft salvage when F-AKP or extra-anatomic graft failure reproduces critical ischemia. Conversely, a new bypass to a virginal outflow site, preferably with autologous vein, should be performed when a polytetrafluoroethylene F-BKP or F-D bypass fails

Although cyclosporine (CsA) is widely used as the primary agent for inhibiting the rejection of organ allografts in man, the ideal immunosuppressive regimen for utilizing this drug is still uncertain. To investigate this question, a concanavalin A (con A)-dependent cell-mediated cytotoxicity (CDCMC) assay was used to examine the development of intragraft and peripheral blood cytolytic T lymphocyte activity during CsA dose tapering. These studies were conducted in a canine single-lung transplantation model that facilitates serial examination of intragraft effector cells by bronchoalveolar lavage (BAL). A remarkable correlation of increased intragraft CDCMC and clinical evidence of lung allograft rejection was observed during CsA dose tapering in some recipients. In other recipients CDCMC remained low and evidence of rejection was not observed during drug tapering. In contrast, peripheral blood CDCMC did not correlate well with evidence of rejection. Rejection phenomena observed after termination of CsA therapy were reversed by resumption of CsA treatment but were not reversed by administration of methylprednisolone. Furthermore, the increased level of CDCMC was diminished by reinstitution of CsA therapy at the initial dosage. Following termination of CsA therapy, a prolonged period of unresponsiveness was observed in nearly two-thirds of the recipients, and 60% of these latter dogs had unlimited survival of their lung allografts (median greater than 496 days). Intragraft CDCMC remained low during the periods of unresponsiveness and increased upon onset of rejection. We conclude that measurement of intragraft CDCMC is a useful in vitro method of monitoring lung allograft rejection, and therefore provides a technique for adjusting CsA dosage schedules to achieve maximally effective immunosuppression. The use of this assay for monitoring rejection of other organ grafts requires further investigation

Although advanced age has often been a relative contraindication to attempts at limb salvage, we have not regarded it as an important deterrent to arterial reconstruction. Our 6-year experience with 168 consecutive patients over 80 years of age who underwent arterial reconstruction or percutaneous transluminal angioplasty represented 18% of all patients treated with limb-threatening ischemia during this period. The average age was 84 years, with 14 patients over 90 years of age. Sixty-eight patients were men (41%) and 100 were women (59%). Indications for treatment in 189 limbs were restricted to limb salvage. One hundred eighty-two operative procedures were performed consisting of 84 femoropopliteal, 72 femorotibial, 12 axillofemoral, 11 femorofemoral, two axillopopliteal and one iliofemoral bypass. Percutaneous transluminal angioplasty was performed in 12 iliac and 14 femoral or popliteal arteries as an alternative (seven) or adjunct (19) to vascular reconstruction. The 30-day procedural mortality rate was 6%. The cumulative life table survival rate of all patients who underwent an attempt at limb salvage was 78% at 1 year, 65% at 2 years, and 54% at 3 years. Cumulative life table limb salvage rates were 84% at 1 year, 74% at 2 years, and 71% at 3 years. Overall graft patency for 182 arterial reconstructive operations was 80% at 1 year and 62% at 3 years. Of patients in whom limb salvage was attempted, 65% lived more than 1 year and 51% more than 2 years with a functional limb. Of patients who died within 5 years of treatment, 76% did so with their previously threatened limb intact. These data support an aggressive approach to arterial reconstruction in elderly patients and indicate that advanced age alone should not be considered a contraindication to attempts at limb salvage

Leg wound complications following saphenous vein harvest for coronary revascularization are uncommon. We have encountered five patients in whom unrecognized arterial occlusive disease contributed to wound necrosis. All required vascular reconstruction in addition to local wound care to achieve healing. Careful preoperative attention to symptoms of arterial insufficiency is recommended and appropriate modification of lower extremity incisions may reduce the frequency of this complication. Prompt recognition and appropriate arterial revascularization should avoid prolonged morbidity if ischemic necrosis of leg wounds does occur. If arterial reconstruction is required, PTFE is an acceptable graft material if the remaining saphenous vein is inadequate for use

Autologous saphenous vein (ASV) and polytetrafluoroethylene (PTFE) grafts were compared in 845 infrainguinal bypass operations, 485 to the popliteal artery and 360 to infrapopliteal arteries. Life-table primary patency rates for randomized PTFE grafts to the popliteal artery paralleled those for randomized ASV grafts to the same level for 2 years and then became significantly different (4-year patency rate of 68% +/- 8% [SE] for ASV vs. 47% +/- 9% for PTFE, p less than 0.025). Four-year patency differences for randomized above-knee grafts were not statistically significant (61% +/- 12% for ASV vs. 38% +/- 13% for PTFE, p greater than 0.25) but were for randomized below-knee grafts (76% +/- 9% for ASV vs. 54% +/- 11% for PTFE, p less than 0.05). Four-year limb salvage rates after bypasses to the popliteal artery to control critical ischemia did not differ for the two types of randomized grafts (75% +/- 10% for ASV vs. 70% +/- 10% for PTFE, p greater than 0.25). Although primary patency rates for randomized and obligatory PTFE grafts to the popliteal artery were significantly different (p less than 0.025), 4-year limb salvage rates were not (70% +/- 10% vs. 68% +/- 20%, p greater than 0.25). Primary patency rates at 4 years for infrapopliteal bypasses with randomized ASV were significantly better than those with randomized PTFE (49% +/- 10% vs. 12% +/- 7%, p less than 0.001). Limb salvage rates at 3 1/2 years for infrapopliteal bypasses with both randomized grafts (57% +/- 10% for ASV and 61% +/- 10% for PTFE) were better than those for obligatory infrapopliteal PTFE grafts (38% +/- 11%, p less than 0.01). These results fail to support the routine preferential use of PTFE grafts for either femoropopliteal or more distal bypasses. However, this graft may be used preferentially in selected poor-risk patients for femoropopliteal bypasses, particularly those that do not cross the knee. Although every effort should be made to use ASV for infrapopliteal bypasses, a PTFE distal bypass is a better option than a primary major amputation

CsA immunosuppression has resulted in decreased graft loss from rejection. However, rejection episodes do occur and, in fact, rejection remains as the major cause of graft loss in the CsA-treated patient. CsA, itself, has added to the differential diagnosis of renal dysfunction following transplantation. In the majority of circumstances, rejection can be differentiated from CsA nephrotoxicity as well as other causes of renal dysfunction by a combination of clinical presentation, renal scan and sonography, CsA levels, and percutaneous allograft biopsy. In some circumstances, a therapeutic trial of lowering the CsA dose may be indicated before extensive laboratory study. Most acute rejection episodes will respond to increased steroid doses. In patients with low CsA levels, increasing the CsA dose may be advised. Steroid-resistant rejection frequently responds to ALG. Patients with repeated episodes of renal dysfunction may be stabilized by using the combination of prednisone, azathioprine, and CsA

Thirty-one episodes of biopsy-proved acute rejection (R) in 28 patients maintained on cyclosporine did not respond to high-dose steroids and were treated with antilymphocyte globulin (ALG). Cyclosporine was discontinued in all but three during ALG administration. (A) Twenty-four patients received 26 courses of ALG within 90 days of transplant (11 1st R, 15 2nd or 3rd). Seven treatment courses were cut short due to infection (4), ongoing R (2) and a combination of infection and rejection (1). Only 1 of 7 has a functioning graft. Of the remaining 19 full ALG courses (17 patients) (8 1st R, 11 2nd or 3rd), 13 (11 patients) responded (7 1st R, 6 greater than 1st). The remaining 6 patients lost their grafts to ongoing acute rejection. (B) Five patients were treated after 6 months posttransplant; two responded but no grafts currently function. (C) Overall 7 patients developed systemic infection (7 viruses, 1 Candida) with 1 death, and 2 additional patients developed severe thrombocytopenia and leukopenia. Patients responding to their ALG course were restarted on cyclosporine. We conclude that ALG is not as effective in reversing steroid-resistant rejection in patients maintained on cyclosporine as it has been in patients maintained on azathioprine. However, more than 50% of steroid-resistant rejection episodes are reversed