Effect of Body Mass Index on Early Outcomes of Endovascular Abdominal Aortic Aneurysm Repair.

BACKGROUND

This study compares the presentation, management, and outcomes of patients undergoing endovascular abdominal aortic aneurysm repair (EVAR), based on their weight status as defined by their body mass index (BMI).

METHODS

Patients with primary EVAR for ruptured and intact abdominal aortic aneurysm (AAA) were identified in the National Surgical Quality Improvement Program database (2016-2019). Patients were categorized by weight status (underweight: BMI < 18.5 kg/m, normal weight: 18.5-24.9 kg/m, overweight: 25-29.9 kg/m, Obese I: 30-34.9 kg/m, Obese II: 35-39.9 kg/m, Obese III: > 40 kg/m). Preoperative characteristics and 30-day outcomes were compared.

RESULTS

Of 3,941 patients, 4.8% were underweight, 24.1% normal weight, 37.6% overweight, and 22.5% with Obese I, 7.8% Obese II, and 3.3% Obese III status. Underweight patients presented with larger (6.0 [5.4-7.2] cm) and more frequently ruptured (25.0%) aneurysms than normal weight patients (5.5 [5.1-6.2] cm and 4.3%, P < 0.001 for both). Pooled 30-day mortality was worse for underweight (8.5%) compared to all other weight status (1.1-3.0%, P < 0.001), but risk-adjusted analysis demonstrated that aneurysm rupture (odds ratio [OR] 15.9, 95% confidence interval [CI] 8.98-28.0) and not underweight status (OR 1.75, 95% CI 0.73-4.18) accounted for increased mortality in this population. Obese III status was associated with prolonged operative time and respiratory complications after ruptured AAA, but not 30-day mortality (OR 0.82, 95% CI 0.25-2.62).

CONCLUSIONS

Patients at either extreme of the BMI range had the worst outcomes after EVAR. Underweight patients represented only 4.8% of all EVARs, but 21% of mortalities, largely attributed to higher incidence of ruptured AAA at presentation. Severe obesity, on the other hand, was associated with prolonged operative time and respiratory complications after EVAR for ruptured AAA. BMI, as an independent factor, was however not predictive of mortality for EVAR.