Outcomes of Open vs Endovascular Repair of Abdominal Aortic Aneurysm Involving the Iliac Bifurcation.

Background

Aneurysmal involvement of the iliac bifurcation increases the complexity of both open and endovascular repair of abdominal aortic aneurysm (AAA), potentially raising the risk of postoperative complications. Randomized trials comparing endovascular aneurysm repair (EVAR) and open aortic repair (OAR) for AAA showed that EVAR is associated with a lower postoperative mortality rate. However, it remains unclear whether these results apply to AAA involving the iliac bifurcation (AAAIB). Several small single-institutional studies have shown conflicting results. This study aims to compare the outcomes of EVAR and OAR for AAAIB in a real-world, multi-institutional setting.

Methods

The Society for Vascular Surgery (SVS) Vascular Quality Initiative (VQI) database was queried for patients who underwent repair for AAAIB. The cohort was divided into two groups based on the intervention: EVAR vs OAR. Baseline demographic, clinical, and perioperative characteristics, as well as outcomes such as overall 30-day mortality, in-hospital mortality, Major Adverse Cardiovascular Events (MACE: death, myocardial infarction, stroke), intestinal ischemia, overall reinterventions, and 1-year survival, were compared between the groups. Univariable analysis, multivariable inverse probability-weighted regression (IPWR), survival analysis with the Kaplan-Meier method, log-rank test, and Cox proportional hazards regression were performed.

Results

Of all reviewed patients, 7,535 were included in the final analysis, of whom 5,742 (76.2%) underwent EVAR, whereas 1,793 (23.8%) underwent OAR. In IPWR models, patients who underwent EVAR had significantly lower odds of overall in-hospital mortality (OR: 0.25, 95%CI: 0.18-0.34, p<0.001), 30-day mortality (OR: 0.31, 95%CI: 0.23-0.42, p<0.001), MACE (OR: 0.24, 95%CI: 0.19-0.31, p<0.001), and other postoperative adverse events compared to OAR. The Cox proportional hazards model demonstrated a significantly higher 1-year survival rate for EVAR compared to OAR (HR: 0.61, 95% CI: 0.50-0.76, p<0.001).

Conclusions

In this real-world, multi-institutional study, EVAR for AAAIB was associated with lower odds of overall in-hospital mortality, 30-day mortality, MACE, as well as a higher 1-year survival rate, compared to the OAR. EVAR should be considered the primary method for repairing aortoiliac aneurysm involving the iliac bifurcation in anatomically suitable patients. Longer follow-up studies are needed to confirm these findings and compare the long-term reintervention and aorta-related mortality rates between the two treatment modalities.