Long-term dilatation of polyester and expanded polytetrafluoroethylene tube grafts after open repair of infrarenal abdominal aortic aneurysms

Abstract

Objectives: Since 1995, expanded polytetrafluoroethylene (ePTFE) grafts have been implemented in open surgical repair (OSR) of abdominal aortic aneurysms (AAA) and are supposed to show less dilatation than polyester grafts. This study examined differences in graft dilatation and clinical outcome.

Methods: This single-center long-term, prospective randomized study monitored 99 consecutive patients after OSR of AAA. Implanted were 90 tube ePTFE Gore-Tex Stretch grafts, 56 tube Dacron grafts (Uni-Graft KDV, polyester, B. Braun, knitted), and 51 tube Dacron grafts (Gelseal Plus, polyester, Vascutek, triaxial knitted). Follow-up with ultrasound examination was performed at discharge, at 12 months, and at 6 years.

Results: Patients were a mean age of 67 years. Thirty-day mortality was 2.5% (n = 5 of 199), without significant differences among the groups. The Kaplan-Meier analysis showed 5-year survivals of 0.82 (ePTFE/Gore), 0.81 (polyester/Braun), and 0.83 (polyester/Vascutek). Mean ± standard deviation dilatation of the midgraft segment was 1% ± 5% (ePTFE/Gore), 10% ± 9% (polyester/Braun), and 7% ± 8% (polyester/Vascutek) (P ≤ .001) at discharge; 8% ± 11% (ePTFE/Gore), 24% ± 7% (polyester/Braun), and 20% ± 13% (polyester/Vascutek; P ≤ .001) after 12 months; and 19% ± 21% (ePTFE/Gore), 33% ± 22% (polyester/Braun), and 23% ± 19% (polyester/Vascutek; (P ≤ .001) after 6 years. No graft failure or rupture occurred. Graft patency was 100%.

Conclusions: After a mean implantation of 6 years, the ePTFE/Gore, polyester/Braun, and polyester/Vascutek tube grafts presented with significant differences. The ePTFE grafts showed a stronger resistance against dilatation than the two types of polyester grafts. Owing to similar perioperative and postoperative courses, no advantage could be identified in any group concerning the overall outcome. Vascular implants for OSR of AAA made of ePTFE and polyester are safe, even after a long implantation time. Therefore, the choice of the suitable graft does not depend on its postimplantation dilative characteristics. The outcome is not likely to be connected with dilatation of the implanted graft, because a causal connection between graft dilatation and death cannot be made. The study does not offer a basis for the preference of one of the three graft types. Nevertheless, continuous ultrasound examinations should be performed after implantation of an aortic tube graft to identify possible problems arising from changes in the graft and the residual vascular branches over time.