Adjunctive Primary Stenting of Endograft Limbs During Endovascular Abdominal Aortic Aneurysm Repair: Implications for Limb Patency

Nayan Sivamurthy, MD, Vascular Surgery, UCSF Medical Center, San Francisco, CA; Darren B. Schneider, MD, San Francisco, CA; Linda M. Reilly, MD, San Francisco, CA; Joseph H. Rapp, MD, San Francisco, CA; Herman Skovobogatyy, San Francisco, CA; Timothy A.M. Chuter, MD, San Francisco, CA;

Purpose: Endograft limb occlusion is an infrequent, but serious complication of endovascular abdominal aortic aneurysm repair. Insertion of additional stents within the endograft limb may prevent future occlusion. This study evaluates limb patency after adjunctive stenting of endograft limbs.
Methods: We performed a retrospective review of patients who underwent endovascular abdominal aortic aneurysm repair (N=248) with the Zenith AAA endovascular graft between 1999 and 2004. Among these patients, two groups were identified: patients with (N=54) and without (N=194) additional bare stent placement in endograft limbs at the time of endovascular abdominal aortic aneurysm repair. 54 patients had 70 endograft limbs stented (71% Wallstent; 33% Palmaz). Indications for additional stent placement included severe endograft limb angulation (56%), endograft limb stenosis (56%), and endoleak (6%). Serial postoperative CT scan and plain abdominal x-rays were reviewed to assess limb patency and anatomy.
Results: There were 12 women (22%) in the stented group, and 24 (12%) in the unstented group (P=.07), which probably reflects a higher incidence of distorted iliac artery anatomy among women. The technical success rate of stenting (correction of anatomic abnormality) was 100%. In patients with adjunctive limb stenting, there were no cases of endograft limb occlusion. In the non-stented population, 13 patients (7%) had 13 limb occlusions. 73% of occlusions occurred within 6 months of endovascular abdominal aortic aneurysm repair. Reasons for occlusion included severe angulation (N=10), limb stenosis (N=4), heparin-induced thrombocytopenia (N=1), and iliac dissection (N=1). Interventions to restore perfusion were successfully performed in 11 patients (85%). These included thrombectomy (N=5), stent placement (N=4), femoral-femoral bypass (N=4), and thrombolysis (N=2). Primary patency at 3 years in the stented and non-stented limbs was 100±0% and 88±5% respectively (P<.05, figure). There was no difference in endograft distal limb implantation location or minimum endograft limb diameter between the stented group and the occluded group (P=NS).
Conclusions: Severe endograft limb angulation and stenosis are predominant causes of limb occlusion after endovascular abdominal aortic aneurysm repair. Correction of these anatomic problems is technically feasible with additional stents. Aggressive stenting of endograft limbs for angulation or stenosis at the time of endovascular abdominal aortic aneurysm repair improves endograft limb primary patency and reduces limb occlusion rates.