Frailty Among Veterans Undergoing Abdominal Aortic Aneurysm Repair

Background: Frailty is a known risk factor for adverse outcomes following surgery and affects at least 3 of every 10 US Veterans aged 65 years and older. We designed a study to characterize the association between frailty and complications after endovascular aneurysm repair (EVAR) compared to open aneurysm repair (OAR) at our regional Veterans Affairs Medical Center.

Methods: Veterans who underwent either OAR or EVAR at our institution between January 1, 2000 and December 31, 2020 were identified. We examined medical history, procedure characteristics, perioperative complications, and frailty as measured by the 5-factor modified frailty index (mFI-5). Frailty was defined as an mFI-5 score ≥2. Primary endpoints were postoperative complications, duration of surgery, and length of hospital stay. Tests of association were performed with t-test and chi-squared analysis.

Results: Over the 21-year period, we identified 314 patients that underwent abdominal aortic aneurysm (AAA) repair with 115 (36.6%) OAR and 199 EVAR (63.4%) procedures. Patients undergoing EVAR were older on average (72.1 years vs. 70.2 years) and had a higher average mFI-5 compared to the open repair group (1.49 vs. 1.23, P = 0.036). When comparing EVAR and OAR cohorts, patients undergoing OAR had a larger AAA diameter (6.5 cm, standard deviation [SD]: 1.5) compared to EVAR (5.5 cm, SD: 1.1 P < 0.0001). Fewer frail patients underwent OAR (n = 40, 34.8%) compared to EVAR (n = 86, 43.2%), and frail EVAR patients had higher AAA diameter (5.8 cm, SD: 1.0) compared to nonfrail EVAR patients (5.3 cm, SD 1.2), P = 0.003. Among OAR procedures, frail patients had longer operative times (296 min vs. 253 min, P = 0.013) and higher incidence of pneumonia (17.5% vs. 5.3%, P = 0.035). Among frail EVAR patients, operative time and perioperative complications including wound dehiscence, surgical site infection, and pneumonia were not significantly different than their nonfrail counterparts. Overall, frail patients had more early complications (n = 55, 43.7%) as compared to nonfrail patients (n = 48, 25.5%, P = 0.001). OAR patients had higher rates of postoperative complications including wound dehiscence (7.0% vs. 0.5%, P = 0.001), surgical site infections (7.0% vs. 1.0%, P = 0.003), and pneumonia (9.6% vs. 0.5%, P=<0.0001). Open repair was also associated with overall longer average intensive care unit stays (11.0 days vs. 1.6 days, P < 0.0001) and longer average hospitalizations (13.5 days vs. 2.4 days, P < 0.0001).

Conclusions: Our findings demonstrate that frailty is associated with higher rates of adverse outcomes in open repair compared to EVAR. Patients who underwent open repair had higher rates of wound dehiscence, surgical site infection, and pneumonia, compared to those undergoing endovascular repair. Frailty was associated with larger AAA diameter in the EVAR cohort and longer operative times, with higher frequency of postoperative pneumonia in the OAR cohort. Frailty is a strong risk factor that should be considered in the management of aortic aneurysms.