LAUSR

OBJECTIVE Female patients are more likely to undergo repair of intact and ruptured abdominal aortic aneurysm (AAA) at smaller aortic diameter compared with male patients. By adjusting for inherent anatomic differences between sexes, aortic size index (ASI) and aortic height index (AHI) may provide an additional method for guiding treatment. We therefore analyzed sex-specific criteria for AAA repair using aortic diameter, ASI, and AHI. METHODS We identified all patients who underwent AAA repair between 2003-2019 in the Vascular Quality Initiative database. The Dubois and Dubois formula was used to calculate body surface area (BSA), aortic diameter was divided by BSA to calculate ASI. Aortic diameter was divided by height to calculate AHI. Cumulative distribution curves were used to plot the proportion of patients who underwent repair of ruptured aneurysm according to aortic diameter, ASI, and AHI. Multivariable logistic regression modeling was used to identify the association of female sex with perioperative mortality and any major postoperative complication. RESULTS We identified 55,647 patients, of whom 12,664 were female (20%). For both intact and rupture repair, female patients were older, less likely to undergo EVAR, and more likely to have comorbid conditions. Female patients underwent repair at smaller median aortic diameter compared with male patients for intact (5.4 vs 5.5cm, P<.001) and rupture repair (6.7 vs 7.7cm, P<.001). However, ASI was higher in female patients for both intact (3.1 vs 2.7cm/m2, P<.001) and rupture repair (3.8 vs 3.7cm/m2, P<.001). Whereas AHI was higher in female patients for intact repair (3.3 vs 3.1cm/m, P<.001) but lower for rupture repair (4.1 vs 4.3cm/m, P<.001). When analyzing the cumulative distribution of rupture repair in male patients, 12% of rupture repairs were performed at an aortic diameter below 5.5cm. To achieve the same proportion of rupture repair in female patients, the repair diameter was only 4.9cm. However, when ASI and AHI were used, female and male patients both reached 12% of rupture repair at an ASI of 2.7cm/m2 and an AHI of 3.0cm/m. CONCLUSION Our study provides data to strongly support the sex-specific 5.0cm aortic diameter threshold suggested for repair in female patients by the Society for Vascular Surgery. The high percentage of patients undergoing rupture repair below 5.5cm in male patients and 5.0cm in female patients highlights the need to better identify patients at risk of rupture at smaller aortic diameters.