The fact that these two prosthetic grafts performed in equivalent fashion in a controlled, well-conducted prospective study is not surprising in spite of the previous work that suggested differences. If the preferential use of synthetic bypass grafts above the knee is to be used, it should be restricted to older nonsmokers with favorable anatomy. In that instance, the choice of graft material will depend on handling characteristics and cost. Above-knee prostheses should be only selectively used in younger, smoking patients, and graft size should be carefully considered in patients who undergo this operation.

Although the type of prosthetic used for above-knee femoropopliteal bypass grafts does not affect 5-year patency rates, age and graft size do influence results. These factors should be considered before a prosthetic bypass grafting procedure. Furthermore, these data should serve as a contemporary standard, with which evolving and conventional procedures can be compared.

Glutaraldehyde treated human umbilical veins (Dardik Biograft) were used to bypass short segments of the femoral artery in 15 dogs and were compared to autogenous jugular veins placed in the contralateral femoral artery of each animal. All 15 autogenous jugular veins remained patent for the four month period of observation whereas thrombosis occurred in seven of 15 umbilical vein grafts. This patency rate of 53% was significantly lower than that observed for autogenous jugular veins (p less than 0.01). Neointimal Fibrous Hyperplasia (NFH) a the proximal anastomosis was responsible for six of the seven umbilical vein graft occlusions. Of the eight patent umbilical veins, five had varying degrees of proximal anastomotic stenosis secondary to NFH. Histological examination of each graft revealed significant fibroblastic proliferation and collagen deposition within the lumen of stenosed and thrombosed grafts. Although human umbilical veins have distinct advantages over other prosthetics, such as availability and flexibility, the incidence of experimental neointimal fibrous hyperplasia causing anastomotic stenosis and thrombosis is prohibitively high.

No abstract

Extra-anatomic bypass of the abdominal aorta was performed in 25 patients too ill to undergo abdominal operation (Group I) and in 22 patients with graft sepsis or hemorrhage (Group II). The graft patency rate determined by life table analysis in Group I patients was 83.5% at one year and 60% at two years. The graft patency rate for Group II patients of 47% at one year was significantly lower than the patency rate for Group I patients (p <.01). Thrombectomy was attempted in 11 of the 18 grafts that occluded postoperatively. Patency was re-established by this method in nine grafts (82%), failures resulted in amputation. Recurrent occlusion of three thrombectomized grafts was treated by multiple thrombectomies with cumulative patencies up to 44.5 months. Thrombectomy was not attempted in seven occluded grafts. Two graft occlusions resulted in amputation of extremities. Contralateral axillofemoral grafts were performed in three of the patients, ipsilateral axillofemoral graft in one patient, and aortobifemoral graft in one patient. Thrombectomy is the treatment of choice for occluded extra-anatomic bypass grafts. It can be performed easily under local anesthesia. If unsuccessful, contralateral axillofemoral or femoro-femoral grafts are indicated to re-establish blood flow.