Early and Midterm Outcomes of Chimney Endovascular Aortic Repair for Ruptured Abdominal Aortic Aneurysms.

Purpose: To compare the outcomes of endovascular aortic aneurysm repair using a chimney technique (ch-EVAR) with those of the standard EVAR (st-EVAR) for ruptured abdominal aortic aneurysms (RAAA).

Materials and methods: We implemented ch-EVAR for juxtarenal RAAA based on obvious anatomical indications after converting the strategy for RAAA from open repair to EVAR. A retrospective, cohort-based study was conducted on patients with RAAA who were treated using EVAR in our hospital between July 2011 and March 2022. EVAR cases were extracted, and outcomes were compared between ch-EVAR and st-EVAR. Patient clinical status, anatomical variables, treatment, and follow-up data were evaluated.

Results: A total of 56 (82%) and 12 (18%) patients were treated by st-EVAR and ch-EVAR, respectively. Thirty-day mortality rates were comparable between the 2 groups [8.9% in st-EVAR vs 8.3% in ch-EVAR (p= 0.95)]. Short-term outcomes showed that no type Ia endoleak occurred in either group. Midterm outcomes, including sac enlargement [7.5% in st-EVAR vs 0% in ch-EVAR (p= 0.37)], shrinkage [77.5% in st-EVAR vs 80.0% in ch-EVAR (p= 0.86)], and overall survival and freedom from aneurysm-related reintervention at 3 years [64.7% and 96.4% in the EVAR group vs 91.7% and 100% in the ch-EVAR group, respectively (p= 0.30 and 0.52)], were not significantly different between the 2 groups.

Conclusion: Ch-EVAR for RAAA showed remarkably excellent outcomes, comparable to those of st-EVAR. Ch-EVAR is considered technically feasible in experienced centers. The indications for EVAR for RAAA may be further expanded using the chimney technique, resulting in overall improved outcomes for RAAA.

Clinical impact: This is a retrospective, single-center analysis of 68 patients with ruptured abdominal aortic aneurysms (RAAAs) treated by endovascular repair (EVAR) to investigate the efficacy of the chimney technique for juxtarenal RAAA. Thirty-day mortality rate was 8.3% for the chimney EVAR group, which was equivalent to that in the standard EVAR group. Mid-term outcomes including sac enlargement/shrinkage, overall survival, and freedom from aneurysm-related reintervention were comparable between the two groups. This report suggests the possibility of broadening the selection criteria of the current endovascular strategy using the chimney technique.