Robotic Partial Nephrectomy for Renal Tumors Larger Than 4 Cm

Background: Minimally invasive partial nephrectomy (PN) is most commonly performed for renal tumors < or =4 cm in size. Robotic PN (RPN) for tumors >4 cm has not been assessed.

Objective: To evaluate the safety and feasibility of RPN for tumors >4 cm in the context of patients undergoing RPN for tumors < or =4 cm.

Design, Setting, And Participants: We reviewed data for 71 consecutive patients who underwent transperitoneal RPN at a tertiary care center between August 2007 and September 2009 by a single surgeon. Patients were stratified into two groups: 15 with tumors >4 cm on preoperative imaging (group 1) and 56 patients with tumors < or =4 cm (group 2).

Intervention: All patients underwent transperitoneal RPN by a single surgeon.

Measurements: Preoperative, perioperative, pathologic, and functional outcomes data were analyzed and compared between groups. We used chi(2) and student t tests for categorical and continuous variables, respectively. A p value <0.05 was considered statistically significant.

Results And Limitations: Mean radiographic tumor size was 5.0 cm (4.1-7.9) for group 1 and 2.1cm (0.7-3.8) for group 2. No significant differences were found between groups for estimated blood loss, total operative time, hospital stay, complication rates, and change in estimated glomerular filtration rate. Patients with larger tumors had longer median warm ischemia times (25 vs 20 min; p=0.011). Limitations of our study include the retrospective nature the analysis, small sample size, and single-surgeon experience.

Conclusions: In our initial experience, RPN for tumors >4 cm is safe and feasible, showing comparable outcomes to RPN for smaller tumors, although with longer warm ischemia times. Future studies with extended follow-up are necessary to determine the viability of RPN for large tumors as an effective form of treatment.