Retroperitoneal versus transperitoneal robotic-assisted laparoscopic partial nephrectomy: a matched-pair, bicenter analysis with cost comparison using time-driven activity-based costing.

ABSTRACT

PURPOSE OF REVIEW To perform a bicenter, retrospective study of perioperative outcomes of retroperitoneal versus transperitoneal robotic-assisted laparoscopic partial nephrectomy (RALPN) and assess costs using time-driven activity-based costing (TDABC). We identified 355 consecutive patients who underwent RALPN at University of California Los Angeles and the University of Michigan during 2009-2016. We matched according to RENAL nephrometry score, date, and institution for 78 retroperitoneal versus 78 transperitoneal RALPN. Unadjusted analyses were performed using McNemar's Chi-squared or paired t test, and adjusted analyses were performed using multivariable repeated measures regression analysis. From multivariable models, predicted probabilities were derived according to approach. Cost analysis was performed using TDABC. RECENT FINDINGS: Patients treated with retroperitoneal versus transperitoneal RALPN were similar in age (P = 0.490), sex (P = 0.715), BMI (P = 0.273), and comorbidity (P = 0.393). Most tumors were posterior or lateral in both the retroperitoneal (92.3%) and transperitoneal (85.9%) groups. Retroperitoneal RALPN was associated with shorter operative times (167.0 versus 191.1 min, P = 0.001) and length of stay (LOS) (1.8 versus 2.7 days, P < 0.001). There were no differences in renal function preservation or cancer control. In adjusted analyses, retroperitoneal RALPN was 17.6-min shorter (P < 0.001) and had a 76% lower probability of LOS at least 2 days (P < 0.001). Utilizing TDABC, transperitoneal RALPN added $2337 in cost when factoring in disposable equipment, operative time, LOS, and personnel. SUMMARY: In two high-volume, tertiary centers, retroperitoneal RALPN is associated with reduced operative times and shortened LOS in posterior and lateral tumors, whereas sharing similar clinicopathologic outcomes, which may translate into lower healthcare costs. Further investigation into anterior tumors is needed.