Comparison of In-Hospital Outcomes between Open Aneurysm Repair and Endovascular Aneurysm Repair for Ruptured Abdominal Aortic Aneurysm: A Retrospective Cohort Study Using Japanese Administrative Data.

Objective: To comparatively examine in-hospital mortality between open aneurysm repair (OAR) and endovascular aneurysm repair (EVAR) for ruptured abdominal aortic aneurysm (rAAA) in Japan. Methods: Using administrative data, this retrospective cohort study analyzed rAAA patients treated at 482 Japanese acute care hospitals between April 1, 2018 and March 31, 2021. Patients were assigned to an OAR group or EVAR group. The propensity score for EVAR was calculated, and logistic regression analysis using inverse probability of treatment weighting was performed with in-hospital mortality as the dependent variable and surgical procedure (EVAR vs OAR) as the main independent variable of interest. Results: The OAR group and EVAR group comprised 2650 patients from 372 hospitals and 2656 patients from 356 hospitals, respectively. In-hospital mortality was significantly higher (P <0.01) in the OAR group (11.7%) than in the EVAR group (9.4%). The logistic regression analysis calculated the odds ratio for in-hospital mortality to be 0.74 (95% confidence interval: 0.60-0.92; P <0.01) in the EVAR group (reference: OAR group). Conclusion: EVAR was significantly associated with reduced in-hospital mortality and shorter hospitalizations in patients treated for rAAA in Japan.