Robot-assisted partial nephrectomy in morbidly obese patients: a VCQI database study

Abstract

To compare perioperative outcomes following robot-assisted partial nephrectomy (RAPN) in patients with morbid obesity (body mass index (BMI > 40 kg/m(2))) and non-obese patients. Using the Vattikuti Collective quality initiative (VCQI) database for RAPN, data for morbidly obese and non-obese patients was obtained. Propensity scores were calculated for two treatment groups (morbidly obese vs. non-obese) for the following variables i.e. age, sex, tumor size, RNS, surgical access (retroperitoneal/transperitoneal) and estimated glomerular filtration rate (eGFR) to ensure comparability. The primary outcome for the study was comparison of trifecta between the two groups. In this study, 158 morbidly obese patients were matched with 158 non-obese patients undergoing RAPN. Two groups matched well for age, sex, tumor size, eGFR and RNS. There was no difference between two groups for ischemia time, blood loss, blood transfusion, conversion to radical nephrectomy, length of stay, intraoperative and postoperative complications. Operative time was longer in morbidly obese patients (median 210 min vs. 120 min, p = 0.000). On pathological analysis, malignant tumors were more likely in the morbidly obese group (83.1% vs.73.4%, p = 0.018). Trifecta outcomes were comparable between the two groups (60.1% vs. 63.3%, p = 0.563). The Median duration of follow-up was 12 months (1-96 months). The morbidly obese group had significantly higher day one creatinine (1.25 +/- 0.7 vs. 1.07 +/- 0.37, p = 0.001) and significantly lower day one eGFR (62.1 +/- 19 vs. 69.2 +/- 21, p = 0.018). However, there was no difference between the two groups for the last follow-up creatinine and eGFR. RAPN in morbidly obese patients is associated with equivalent perioperative outcomes compared to non-obese patients.