To evaluate the renal functional outcome, the oncologic safety, and the occurrence of complications after robotic-assisted laparoscopic partial nephrectomy (RPN) for completely endophytic tumors.

Data of 45 patients with completely endophytic tumors, 116 patients with mesophytic, and 64 patients with exophytic masses who underwent RPN were retrospectively analyzed. Perioperative, oncologic, and functional data were evaluated and analyzed with SPSS, version 18.

Demographic characteristics were similar among the groups. The median follow-up of the endophytic, the mesophytic, and the exophytic groups were 48, 43, and 38 months, respectively. Endophytic masses were more likely to be malignant and have a higher overall tumor complexity, estimated by the RENAL score (9 vs 8 vs 5.5; P <.01; P = .02). We did not detect any statistically significant differences among the groups regarding blood loss volume, transfusion rates, length of stay, and intraoperative and postoperative complications (P = .49, .25, .87, .42, and .20, respectively). There was a statistically significant difference in the estimated glomerular filtration rate percentage change on the first postoperative day (P = .02), but this significance was not observed after the first week. The patients in the endophytic group showed a tendency toward increased rates of positive surgical margins compared with the mesophytic and exophytic groups (P = .06). However, there were not any significant differences regarding the recurrence-free survival rates (P = .335) and the overall mortality rates (P = .570) according to the Kaplan-Meier analysis.

In experienced institutes, RPN for entirely intraparenchymal masses is a feasible procedure in terms of complication rates, functional and oncologic outcomes during an intermediate-term period of follow-up.