Early experience with cryopreserved arterial allografts in below-knee revascularization for limb salvage.

BACKGROUND: Below-knee revascularization for limb salvage in the absence of a suitable autogenous saphenous vein is a frequent challenge associated with a high amputation rate. The aim of this prospective study was to evaluate the usefulness of cryopreserved arterial allografts in such cases. METHODS: Arterial allografts were harvested from multiple organ donors and cryopreserved at -80 degrees C. From March 1993 to December 1997, 35 cryopreserved arterial allografts were used as below-knee bypasses for repeated limb salvage in 32 patients. There were 15 men and 17 women with a mean age of 75 years (+/-10.7). Seven patients had rest pain and 25 patients (78%) had gangrene or nonhealing ulceration. Runoff was through a single tibial vessel in 25 cases (71%) and two vessels in 10 cases. Previous ipsilateral bypasses had been done in 26 of 35 limbs (74%). Patients were followed up prospectively for an average period of 18 months (range 2 to 56). RESULTS: Aneurysmal dilatation occurred in two patent grafts, requiring segmental replacement at 13 and 18 months, respectively. The overall primary patency rate was 75% at 6 months, 57% at 12 months, and 39% at 18 months. The overall secondary patency rate was 75% at 6 months, 75% at 12 months, and 59% at 18 months. Overall limb salvage rate was 80% at 12 months, 73% at 18 months. CONCLUSIONS: These early data indicate that below-knee bypass with arterial allografts results in acceptable patency and limb salvage. Arterial allografts may be a useful alternative to other arterial substitutes in a difficult group of patients with critical ischemia and no suitable saphenous vein.

Above-knee femoropopliteal bypass grafting using endothelial cell seeded PTFE grafts: five-year clinical experience.

Early clinical trials using endothelial cells seeded vascular grafts failed to confirm the successful results observed in animals. Differences in seeding methods could at least partially account for this failure. The purpose of the present study was to ascertain the feasibility and intraoperative efficacy of a two-stage technique that allowed high-density seeding as in animals. The first stage of the technique consists of harvesting an autologous vein specimen under local anesthesia followed by enzymatic isolation and in vitro culture of endothelial cells. The second stage is vascular repair. During the procedure the prosthesis is precoated with autologous whole blood or plasma for 30 minutes and seeded at high density with endothelial cells incubated for 45 minutes. Between May 1988 and June 1993, 32 patients were enrolled in this study. In 11 of them, however, the technique could not be completed for various reasons including preoperative infarction in one case, failure to achieve isolation and/or cell cultures in nine cases, and contamination of cell culture in one case. Twenty-one patients (18 men and 3 women) whose mean age was 62 years (range 38 to 78) underwent above-knee femoropopliteal bypass using an endothelial cell seeded polytetrafluoroethylene graft (7 mm). The indication for surgery was intermittent claudication in 20 patients and rest pain in one. The mean size of the vein specimen was 10.5 +/- 3.5 cm2. The mean duration of in vitro cell culture was 23.5 +/- 8.5 days. The mean density of seeding was 2.9 +/- 0.8 x 105 cells/cm2 prosthesis. No major complications were encountered during the immediate postoperative period (30 days). During follow-up two patients with patent bypasses died of intercurrent causes at 2 and 36 months, respectively, one patient had an abscess in the femoral triangle that required removal of the prosthesis (75 days), and three patients presented with bypass failure (2 occlusions and 1 thromboembolic complication) at 3, 10, and 53 months, respectively. Mean follow-up in the 20 patients surviving at 3 months was 42 +/- 15 months. Cumulative primary patency (Kaplan-Meier analysis) was 95% (+/- 10) at 3 months, 89% (+/- 13) at 10 and 48 months, and 67% (+/- 39) at 53 and 76 months. The two-stage seeding technique described herein was feasible in 69% of patients not requiring emergency reconstruction and did not increase perioperative morbidity and mortality. Bypass patency in patients who underwent above-knee femoropopliteal bypass for intermittent claudication was promising.