Endovascular Treatment of Aortoiliac Aneurysms With the Bell-Bottom Technique: A Systematic Review and Meta-Analysis

Aneurysmal degeneration of the common iliac artery (CIA) can pose a challenge to achieve distal landing zone sealing at the time of endovascular abdominal aortic aneurysm repair (EVAR). The aim of this study was to summarize the current literature regarding the bell-bottom technique (BBT) for ectatic CIAs during EVAR.

This study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Eligible articles were identified through a comprehensive search of PubMed, Scopus, and Cochrane Central published until April 2023. A meta-analysis was conducted using the random effects model and the I² statistic was used to assess for heterogeneity. The primary endpoints were type Ib/III endoleak, graft occlusion/limb embolization, and reintervention rate. Secondary endpoints included perioperative adverse events and mortality.

Overall, twenty-six studies and 4332 patients with flared limbs were included. The pooled estimate for type Ib/III endoleak was 4% (95% CI: 2-6, I² = 85.6%), for reintervention rate was 9% (95% CI: 6-12, I² = 90.4%), and for overall mortality was 10% (95% CI: 4-19, I² = 97.3%). No aneurysm related deaths were recorded. Comparative analysis showed similar type Ib/III endoleak, graft occlusion, and reintervention rates between the EVAR BBT, iliac branch endoprosthesis (IBE), and embolization of the internal iliac artery followed by extension of the iliac limb to the external iliac artery (EIE) groups.

The use of flared limbs could be considered a reasonable first line choice for EVAR cases with CIA ectasia as it is simpler, allows for future IBE or EIE and does not increase the risk for type Ib/III endoleak or graft occlusion. Further comparative studies with longer follow-up are needed.