Retroperitoneal Robot-Assisted Partial Nephrectomy in Obese Patients.

To report our experience with retroperitoneal robotic-assisted partial nephrectomy (RAPN) in obese patients. From April 2012 to December 2018, 127 patients with body mass index (BMI) ≥30 kg/m underwent RAPN, of whom 110 patients had retroperitoneal RAPN. We reviewed the patients' demographic, operative data, perioperative and postoperative complications, and postoperative histology. The median BMI was 33.1 kg/m (interquartile range [IQR] 31.5-36.6). The median age of the patients was 59 years. The mean histological size of tumor was 32.2 mm (IQR 23.8-40). The median total surgical time was 130 minutes (IQR 110-176) with a median warm ischemia time of 22.0 minutes. The tumor was located anteriorly in 25% of the cases. The median R.E.N.A.L.* nephrometry score was 6. The median estimated blood loss was 30 mL (IQR 10-80). Three cases were converted to open partial nephrectomy because of bleeding (2.7%). Four patients and one patient returned within 30 days with postoperative complications Clavien-Dindo classification grade 2 and 3a, respectively. Two patients needed perioperative blood transfusion because of bleeding. The median length of stay was 1 day (IQR 1-2). Retroperitoneal RAPN is feasible in patients with high BMI and provides good surgical access to treat nonanterior renal masses. Retroperitoneal RAPN is associated with less blood loss, shorter surgical time, and warm ischemia time when compared with transperitoneal RAPN studies.