Surgery-related outcomes and postoperative split renal function by scintigraphy evaluation in robot-assisted partial nephrectomy in complex renal tumors: an initial case series.

Purpose: To assess surgery-related outcomes and split renal function evaluated by renal scintigraphy in robot-assisted partial nephrectomy (RPN) through the comparison between low and intermediate or highly complex renal tumors.

Methods: In the initial 39 consecutive RPNs performed for solid renal tumors in our hospital, tumors were categorized for their complexity (low, intermediate, and high risk for partial nephrectomy) by R.E.N.A.L. (radius; exophytic/endophytic; nearness; anterior/posterior; location) nephrometry and P.A.D.U.A. (preoperative aspects and dimensions used for an anatomic) scores. The comparison between low, intermediate, and highly complex tumors according to these scoring systems were performed regarding preoperative factors, surgery-related factors, and postoperative renal function factors (split renal function at 3 months and serum creatinine level and estimated glomerular filtration rate (eGFR) at 1 week, 1, 3, 6, and 12 months postoperatively,).

Results: There was no significant difference between low and intermediate or highly complex tumors for all the categories tested in preoperative data. Especially in split renal function, the changes in mercaptoacetyltriglycine (MAG3) effective renal plasma flow (ERPF) from preoperative data were -7.00±20.2 mL/min in low complexity in R.E.N.A.L. nephrometry and -14.1±22.7 mL/min in intermediate or highly complex tumors in R.E.N.A.L. nephrometry (p=0.477), -8.21±21.3 mL/min for low complexity in P.A.D.U.A. and -13.4±22.4 in intermediate or highly complex tumors in P.A.D.U.A. (P=0.607). There was either no significant difference in the decrease of renal function (serum creatinine level and eGFR), operative time, estimated blood loss, or warm ischemia time between low and intermediate or highly complex tumors as measured by both R.E.N.A.L. nephrometry and P.A.D.U.A. scores (P>0.05).

Conclusions: Our data showed that RPN can be performed without compromising the outcome in surgery-related factors and postoperative split renal function even in intermediate or highly complex tumors. Further studies with a larger number of cases need to be performed to confirm these findings.