Biological grafts as arterial substitute in the infragenicular level: A prospective evaluation

Abstract

In order to evaluate patency and clinical success rates, foot salvage rates, and complications associated with the use of two biological graft conduit materials, the authors performed a prospective study of 109 femoroinfrageniculate bypasses performed over six years. The two grafts studied as arterial substitutes were chemically processed human umbilical vein (HUV) graft and ovine collagen graft (OCG). Indications for surgery were disabling claudications (11%), acute ischemia (20%), rest pain (35%), and nonhealing ulceration or gangrene (34%). Sixty-two (57%) operations were repeat procedures for occluded grafts. Major complications occurred in 11.9%: 4 deaths, 1 acute renal failure, 4 graft infections, 4 anastomotic hemorrhages, and 1 case of inadequate graft rinsing. There were 39 early occlusions, which resulted in one-month primary patency rates of 59% (OCG) and 69% (HUV) and secondary patency rates of 71% (OCG) and 87% (HUV). The primary and secondary patency rates at two years were 47% and 58% for OCGs, 42% and 58% for HUVs. The mean foot salvage rates at one month were 82.5% (OCG) and 95.3% (HUV) and at one year were 73% (OCG) and 82% (HUV). These results did not show statistically relevant differences between the two graft materials (chi square = 0.891, p > 0.1). Acute ischemia was associated with a higher percentage of failure when compared with chronic ischemia, but significance was not reached (chi square = 2.77, p = 0.10). However, patients with repeat procedures were associated with higher rates of failure than those undergoing primary procedures (chi square = 5.12, p = 0.025).

Although both types of biograft showed relatively good attrition rates over time, a high early occlusion rate, possibly due to material thrombogenicity, had a detrimental effect on the early patency rate. These results emphasize the importance of autogenous vein grafts for repeat procedures.