CLINICAL AND CT EVALUATION OF A NEW STRETCH POLYTETRAFLUOROETHYLENE AORTIC GRAFT

A new stretch polytetrafluoroethylene (PTFE) aortic graft became avail able for clinical use in early 1991. We prospectively evaluated our fi rst 107 stretch aortic PTFE grafts by means of serial CT imaging and c ompared them with a cohort of concurrently placed Dacron grafts. Stret ch PTFE requires no preclotting and is claimed to resist long-term dil ation and conform well to anastomoses. Consecutive patients undergoing placement of stretch PTFE grafts were seen at least yearly. Within th e first 2 years after implantation, contrast-enhanced CT scans of the abdomen and pelvis were obtained. Caliper measurements were made of th e native arteries and the body and any limbs of the aortic grafts. Gra ft elongation was assessed by noting distortions from the normally cir cular or minimally ovoid configuration of the grafts on transverse CT images. Indications for grafting were elective repair of abdominal aor tic aneurysm in 60 patients, aortoiliac occlusive disease in 31, both aneurysm and occlusive disease in eight, and ruptured abdominal aortic aneurysm in eight. The overall operative mortality rate was 6.5%. The re were two early postoperative graft limb thromboses resulting from h ypercoagulable states, and there was one graft infection. Mean follow- up was 14.1 months (range 1 to 34 months). CT scans were obtained from 61 patients with stretch PTFE grafts and 10 with concomitantly placed Dacron grafts. Ten patients had two or more postoperative CT scans. P rimary stretch PTFE patency was 98% and secondary patency, 100%. There was significantly less dilation of both the graft body and limbs in t he stretch PTFE group (body mean 16.5%, range 6.3% to 28.1%; limb mean 19.3%, range 10% to 43%) compared to the Dacron group (body mean 33%, range 22% to 78%; limb mean 62%, range 12.5% to 88.9%) (p <0.01, unpa ired t test). Those patients with serial scans showed no dilation beyo nd the first scan. No evidence of elongation, kinking, or pseudoaneury sm was noted in any of the stretch PTFE grafts. For a moderate follow- up interval, the new stretch PTFE grafts have performed exceptionally well. There appears to be significantly less dilation with these graft s as compared with Dacron grafts over the same time interval, and ther e has been no evidence of graft elongation to date.