Comparison of Surgical Outcomes Between Resection and Enucleation in Robot-Assisted Laparoscopic Partial Nephrectomy for Renal Tumors According to the Surface-Intermediate-Base Margin Score: A Propensity Score-Matched Study

Objective: To compare the surgical outcomes between resection and enucleation in robot-assisted laparoscopic partial nephrectomy (RAPN) based on the Surface-Intermediate-Base margin score (SIB score). Patients and Methods: This study included 282 patients who underwent RAPN between 2014 and 2016. SIB score was macroscopically evaluated immediately after the surgery. We divided the patients into the following two groups: enucleation (SIB score, 1-2) and resection (SIB score, 3-5). To minimize selection bias between the two surgical methods, patient variables were adjusted by 1: 1 propensity score matching. Results: Of the 282 patients, 48 were assigned to the enucleation group and 234 to the resection group. After matching, 45 patients were included in each group. The mean preoperative estimated glomerular filtration rate (eGFR) was 70 mL/min/1.73m(2). The mean tumor size was 32-33 mm. The decrease in eGFR (5.6 vs 12%, p=0.0365) and total perioperative complication (16% vs 38%, p = 0.0171) were significantly lower in the enucleation group than in the resection group. Estimated blood loss was higher in the enucleation group than in the resection group (129 cc vs 117 cc, p = 0.0088), despite a similar transfusion rate. The postoperative length of hospital stay was shorter in the enucleation group than in the resection group (4.1 vs 5.0 days, p = 0.0288). Operation time and surgical margin status were not significantly different between groups. Conclusions: In carefully selected patients, enucleation was associated with more favorable surgical outcomes in the cohort than resection, including improved renal function and a lower complication rate.