Outcomes of bell-bottom technique compared to standard endovascular aneurysm repair

The bell-bottom technique is a widely used technique to treat aortoiliac aneurysms with preservation of the hypogastric arteries. The published data are scarce with conflicting results regarding the evolution. The aim of this study was to compare the outcomes of patients submitted to endovascular abdominal aortic aneurysm repair with standard technique (S-EVAR) versus bell-bottom technique.

This retrospective cohort study compared the outcomes of standard endovascular aneurysm repair (<16 mm iliac limbs) and bell-bottom technique (≥16 mm iliac limbs) in a tertiary vascular center between 2010 and 2015. The end points of this study were type IB endoleak, reintervention and 30-day mortality. The follow-up protocol included CT scans within 30 days of implantation and 12 months. Duplex ultrasound was performed yearly thereafter.

Two hundred and three patients were treated with bell-bottom technique (n = 84, mean age 72.2 ± 8.9) and S-EVAR (n = 119, mean age 72.7 ± 8.4). The overall 30-day mortality was 1.9%, with no significant difference between groups. There was higher prevalence of coronary heart disease in the bell-bottom technique group compared to the S-EVAR group (41.6% vs. 18.4%, p < 0.01). One patient in the S-EVAR group (0.85%) and four patients in the bell-bottom technique (4.6%) developed type IB endoleak. The mean follow-up period was 35.2 ± 30.4 months. By Kaplan-Meier analysis, freedom from type IB endoleak in 80 months was 85.2% in the bell-bottom technique group and 98.7% in the S-EVAR group (p = 0.05). The freedom from reintervention in 80 months was 74.0% in the bell-bottom technique group and 94.1% in the S-EVAR group (p = 0.6).

This study shows lower freedom from type IB endoleak in the bell-bottom group compared to the standard repair group. There is no significant difference in reoperation rate and 30-day mortality.