A contemporary single-institution retrospective cohort study comparing perioperative outcomes between robotic and open partial nephrectomy for poorly functioning renal moieties in children with duplex collecting systems

Introduction: Studies evaluating robotic-assisted laparoscopic partial nephrectomy (RALPN) are limited to case series, amounting to a lack of studies directly comparing perioperative outcomes for RALPN to open partial nephrectomy (OPN).

Objective: To compare perioperative outcomes between RALPN and OPN.

Methods: A single-institution, retrospective cohort study was performed to compare perioperative outcomes (operative time (OT), length of stay (LOS), complications, readmissions, postoperative interventions, loss in size of the residual moiety, and the presence of postoperative 'contained fluid collections') for RALPN and OPN between February 2007 and July 2014. Descriptive statistics were calculated and unadjusted analyses performed, including Chi-squared/Fisher's exact for categorical variables and Wilcoxon rank sum for continuous variables.

Results: During the study period, 43 partial nephrectomies were performed for benign disease: 27 (63%) RALPN and 16 (37%) OPN. The RALPN cohort was significantly older than the OPN cohort (3.5 vs. 0.8 years; P = 0.003). The cohorts were otherwise similar regarding race, American Society of Anesthesiologist score (ASA), affected moiety, laterality, associated anomalies, moiety function, and surgical indication. Robotic-assisted laparoscopic partial nephrectomy was associated with a significantly shorter LOS (1 vs. 3 days; P = 0.002). Operative time and complication rates were comparable. The OPN group had a longer median follow-up (2.7 years vs. 1.1; P = 0.03). No differences were observed between the cohorts for readmissions, postoperative interventions, loss in size of residual moiety, or development of 'contained fluid collections'. These outcomes are reported in the Summary Table. 'Contained fluid collections' occurred more frequently after lower pole resections (73% vs. 30%; P = 0.009).

Discussion: This study is one of the few to directly compare RALPN to OPN, and demonstrated that RALPN has comparable (if not better) outcomes than OPN. In particular, RALPN provides the advantage of a shorter LOS. Avoiding the flank incision used in OPN may also offer reduced pain; however, this was not studied here and the literature provides weak evidence for this effect. This unadjusted analysis may have been confounded by its short median follow-up and significantly younger OPN cohort.

Conclusion: In this contemporary comparative analysis, RALPN predicted a similar median OT and safety profile to OPN while offering the advantage of a shorter LOS. Regardless of surgical cohort, there were no adverse effects on the residual renal moieties and postoperative 'contained fluid collections' occurred with notable frequency and were independently associated with lower pole pathology.