Obesity and Complication Risk From Radical Cystectomy: Identifying a Body Mass Index Threshold

There are conflicting reports regarding radical cystectomy complication risk from obesity subcategories, and a BMI threshold below which complication risk is notably reduced is undefined. A BMI threshold may be helpful in prehabilitation to aid patient counseling and inform weight loss strategies to potentially mitigate obesity-associated complication risk. This study aims to identify such a threshold and further investigate the association between BMI subcategories and perioperative complications from radical cystectomy.

Data were extracted from the Canadian Bladder Cancer Information System, a prospective registry across 14 academic centers. Five hundred and eighty-nine patients were analyzed. Perioperative (≤90 days) complications were compared between BMI subcategories. Unconditional multivariable logistic regression and cubic spline analysis were performed to determine the association between BMI and complication risk and identify a BMI threshold.

Perioperative complications were reported in 51 (30%), 97 (43%), and 85 (43%) normal, overweight, and obese patients (P = .02). BMI was independently associated with developing any complication (OR 1.04 95% CI 1.01, 1.07). Predicted complication risk began to rise consistently above a BMI threshold of 34 kg/m². Both overweight (OR 2.00 95% CI 1.26-3.17) and obese (OR 1.98 95% CI 1.24-3.18) patients had increased risk of complications compared to normal BMI patients.

Complication risk from radical cystectomy is independently associated with BMI. Both overweight and obese patients are at increased risk compared to normal BMI patients. A BMI threshold of 34 kg/m² has been identified, which may inform prehabilitation treatment strategies.