Risk Factors for Delirium after Abdominal Aortic Aneurysm Repair

Delirium after abdominal aortic aneurysm (AAA) repair is an underreported complication that adversely impacts postoperative recovery. This study aims to characterize risk factors for delirium after AAA repair in older adults using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database.

The ACS-NSQIP database was queried for intact AAA repairs and linked to the Geriatric Surgery and AAA repair modules. The primary outcome was postoperative delirium, determined by a standardized chart-based assessment. Demographics, clinical characteristics, and postoperative outcomes were compared between patients with and without delirium. Backward stepwise logistic regression identified factors independently associated with delirium.

There were 529 repairs (75% endovascular), and 9.5% of patients developed delirium postoperatively. Delirium was more common following open repair compared to endovascular repair (23.8% vs. 4.8%) and with older age (77.4 ± 5.6 vs. 75.6 ± 6.5 years), lower body mass index (26.7 vs. 28.5 kg/m²), and increased bleeding risk (24% vs. 12%) (P < 0.05). Patients with delirium were more likely to have been living alone preoperatively (33% vs. 17%; P = 0.024), but otherwise did not vary in baseline comorbidities including cognitive and functional impairment (P > 0.05). On multivariable analysis, older age, increased bleeding risk, open repair, and paravisceral aneurysm proximal extent were independently associated with delirium.

Among older adults undergoing AAA repair, operative factors were more strongly associated with delirium than patient characteristics. Delirium prevention bundles and monitoring protocols should be prioritized in the perioperative care of older adults at high risk, such as those undergoing open AAA repair.