Robot-assisted partial nephrectomy for moderate to highly complex renal masses. A systematic review and meta-analysis

Introduction: Multiple studies have been published recently assessing feasibility of robot-assisted partial nephrectomy (RAPN) for moderate to highly complex renal masses. Some studies have even compared partial nephrectomy (PN) performed through various modalities such as open PN (OPN) versus RAPN and laparoscopic PN (LPN) versus OPN. The primary aim of this review was to analyze perioperative outcomes such as warm ischemia time (WIT), duration of surgery, estimated blood loss (EBL), complications, blood transfusion, length of stay, and margin status following RAPN for complex renal masses. Another objective was to compare perioperative outcomes following various surgical modalities, i.e., OPN, LPN, or RAPN. Methods: Literature search was conducted to identify studies reporting perioperative outcomes following RAPN for moderate (Radius, Endophytic/Exophytic, Nearness, Anterior/posterior location [RENAL] score 7-9 or Preoperative Aspects of Dimension used for anatomic classification [PADUA] score 8-9) to high complexity renal masses (RENAL or PADUA score >= 10). Meta-analysis of robotic versus OPN and robotic versus LPN was also performed. Study protocol was registered with PROPSERO (CRD42019121259). Results: In this review, 22 studies including 2,659 patients were included. Mean duration of surgery, WIT, and EBL was 132.5-250.8 min, 15.5-30 min, and 100-321 ml, respectively. From pooled analysis, positive surgical margin, need for blood transfusion, minor and major complications were seen in 3.9%, 5.2%, 19.3%, and 6.3% of the patients. No significant difference was noted between RAPN and LPN for any of the perioperative outcomes. Compared to OPN, RAPN had significantly lower EBL, complications rate, and need for transfusion. Conclusions: RAPN for moderate to high complexity renal masses is associated with acceptable perioperative outcomes. LPN and RAPN were equal in terms of perioperative outcomes for complex masses whereas, OPN had significantly higher blood loss, complications rate, and need for transfusion as compared to RAPN.