Multi-institutional feasibility and safety outcomes of retroperitoneal robot-assisted partial nephrectomy in morbidly obese patients.

Background: Robotic-assisted partial nephrectomy (RAPN) is an established treatment modality for small renal masses. While retroperitoneal RAPN (rRAPN) has the benefit of avoiding the peritoneal cavity and provides more direct access to the renal hilum and posterior kidney, there is concern about the feasibility of rRAPN particularly in morbidly obese [body mass index (BMI) ≥40 kg/m2] patients. We present a large scale multi-institutional study on the outcomes of rRAPN in morbidly obese patients. Methods: A retrospective review of a cohort of morbidly obese patients who underwent rRAPN at two academic institutions was performed. Patient characteristics, operative data, and postoperative complication rates were assessed. Results: A total of 22 morbidly obese patients were included for analysis, with a median follow-up duration of 52 months. Median patient age was 61 years and median BMI was 44.9 kg/m2. Based on nephrometry score, 55% of the masses had low complexity and 32% had intermediate complexity. Median operative time was 186.0 minutes and median warm ischemia time was 23.5 minutes. Median postoperative length of stay was 2 days, and only one patient experienced a high-grade complication within 30 days of surgery. Conclusions: rRAPN in select morbidly obese patients appears to have acceptable operative and postoperative outcomes. Further studies and follow-up are needed to better generalization and understand long-term impacts.