Anastomotic false aneurysms: a comparison of braided Dacron and polypropylene sutures

False aneurysms continue to be a problem in vascular surgery and recently polypropylene suture has been incriminated as a major cause. In the last five years, 950 aortofemoral-popliteal reconstructive procedures were performed at our institution. Of these cases, there were 23 patients with anastomotic false aneurysms. We have reviewed this experience with special focus on suture material. In the 23 cases reviewed, there were a total of 29 false aneurysms. The average time interval from operation to clinical presentation of the false aneurysm was five years. Eighty per cent of the aneurysms were at the femoral site. The anastomoses were all end-to-side, and in 93 per cent the graft material was Dacron. The suture material that was used was divided equally between dacron and polypropylene. Aneurysms were blamed on broken suture in only one instance (silk). In 24 aneurysms where the graft had pulled away from the artery, the suture (10 polypropylene, nine Dacron, and two unknown) was noted to be intact. The suture line was not mentioned in one polypropylene and three Dacron related aneurysms. Retrospective review of these 29 false aneurysms leads us to the conclusion that there is no difference between polypropylene and braided Dacron as a factor in the formation of anastomotic false aneurysms in the period studied.