Open surgical conversion after endovascular aneurysm repair in Japan: Indications and outcomes from a multicenter...

This study aimed to evaluate indications and outcomes of open surgical conversion (OSC) after endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm using a multicenter registry in Japan.

Thirteen vascular centers retrospectively reviewed patients who underwent OSC after prior EVAR between 2006 and 2024. Baseline characteristics, indications, procedural details, and outcomes were analyzed. The primary end point was 30-day mortality. Secondary end points were overall survival, aneurysm-related mortality, and freedom from retreatment.

A total of 208 patients (85.6% males; median age, 78 years) were included. The median abdominal aortic aneurysm diameter was 62 mm. The median interval from initial EVAR to OSC was 5.2 years. Indications for OSC were type II endoleak with sac enlargement (47.1%), type I endoleak (23.1%), type V endoleak with sac enlargement (13.0%), infection (10.1%), and type III endoleak (9.6%). The most frequently used stent graft was the Excluder, followed by Endurant and Zenith. Complete stent graft removal was performed in 41 patients, partial removal in 51, and 116 underwent OSC with stent graft preservation. Thirty-eight patients (18.3%) presented with rupture and 48 (23.1%) underwent urgent OSC. The 30-day mortality rate was 4.3% in the overall cohort, 2.4% in nonruptured cases, and 13.2% in ruptured cases. Rupture was a risk factor for 30-day mortality (hazard ratio, 5.93; 95% confidence interval, 1.59-22.1; P = .008). At 10 years, overall survival and aneurysm-related mortality were 58.4% and 14.8%, respectively, and freedom from retreatment rate was 87.5% at 10 years.

Type II endoleak was the leading common indication for OSC after EVAR in this multicenter retrospective study in Japan. Rupture at OSC markedly increased 30-day mortality, even in patients with type II endoleak. Further studies are needed to refine elective indications for OSC to prevent aneurysmal rupture and avoid treatment delay.