A Critical Analysis of Perioperative Outcomes in Morbidly Obese Patients Following Renal Mass Surgery

Objective To evaluate if body mass index (BMI) ≥ 40 is associated with risk of postoperative complications, receipt of perioperative blood transfusion (PBT), length of hospital stay (LOS), perioperative death, or hospital readmission rate following renal mass surgery. Materials and Methods After Institutional Review Board approval, comprehensive information was collected for patients treated with surgery for renal mass from 2000 to 2015 at one institution. Univariable and multivariable analyses were used to evaluate the association of BMI ≥ 40 among other putative risk factors for perioperative outcomes. Results A total of 1048 patients were treated surgically, including 115 (11%) with BMI > 40. Minimally invasive and open surgical approaches were used for 480 (45.8%) and 568 (54.2%) patients, respectively. Morbid obesity was not associated with risk of major complications, overall complications, receipt of PBT, LOS, hospital readmission rate, or perioperative death. Charlson comorbidity index was the only independent predictor of major complications following renal mass surgery, P = .0006, per point odds ratio 1.2 (95%C.I. 1.08-1.32). Surgical site infections (SSIs) were more common in patients with BMI ≥ 40 vs BMI < 40 (10.5% vs 4.8%, P = .01). Following multivariable analysis, BMI ≥ 40 was the only independent predictor of SSIs, odds ratio 2.6, 95% confidence interval 1.32-5.13; P = .006. Conclusion Morbid obesity (BMI ≥ 40) is an independent predictor of developing SSIs following renal mass surgery. Morbid obesity is not predictive of risk for major complications, receipt of PBT, hospital readmission, perioperative death, or LOS.