A Comparative Study of the Efficacy by using Different Stent Grafts in Bell-Bottom Technique for the Treatment of Abdominal Aortic Aneurysm Concomitant with Iliac Artery Aneurysm.

BACKGROUND: Bell-bottom technique (BBT) is one method to preserve the internal iliac artery during endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) that extends to iliac artery. The data on the efficacy of this technique are still limited. We sought to evaluate the midterm efficacy of BBT by using different stent grafts in the treatment of AAA combined with iliac artery aneurysm (IAA).

METHODS: From January 2011 to December 2016, AAA patients with IAA using BBT to preserve the internal iliac artery were retrospectively analyzed in our institution. Patients were followed up at 3, 6, and then every 12 months after surgery. The outcomes among 3 types of stent grafts (Zenith, Excluder, and Endurant) were compared. BBT-related end points including type Ib endoleak, IAA sac expansion, distal neck expansion, and rupture during follow-up were compared. Other events including perioperative death, any other types of endoleak, and corresponding management were also documented.

RESULTS: A total of 125 patients with 141 IAAs were identified. Ninety-eight patients (78.4%) with 113 lesions (80.4%) received a median follow-up time of 38 months. The incidence of type Ib endoleak was 22.9%, 8.3%, 11.9%, and 14.2% (P = 0.19) in Zenith, Excluder, Endurant group, and total patients, respectively. The incidence of IAA sac enlargement was 17.1%, 5.6%, 7.1%, and 9.7% (P = 0.20). The incidence of IAA rupture was 8.6%, 0.0%, 0.0%, and 2.7% (P = 0.03). The incidence of IAA neck enlargement was 34.3%, 13.9%, 16.7%, and 21.2% (P = 0.07). Totally, 14 cases (10.7%) received further treatment for BBT-related issues.

CONCLUSIONS: Although BBT remains a safe and effective treatment option to preserve internal iliac artery during standard EVAR with acceptable complication rates in Asians, different IAA rupture rates were found among 3 different stent grafts. Our data for the first time revealed that the type of stent grafts has influence on the final clinical outcome. Based on that, iliac extension should be selected appropriately while treating AAA-IAA.