Re.: Multi-institutional analysis of robotic partial nephrectomy for hilar versus nonhilar lesions in 446 consecutive cases.

BACKGROUND Minimally invasive approaches to partial nephrectomy have been rapidly gaining popularity but require advanced laparoscopic surgical skills. Renal hilar tumors, due to their anatomic location, pose additional technical challenges to the operating surgeon. OBJECTIVE We compared the outcomes of robot-assisted partial nephrectomy (RPN) for hilar and nonhilar tumors in our large multicenter contemporary series of patients. DESIGN, SETTING, AND PARTICIPANTS We retrospectively reviewed prospectively collected data on 446 consecutive patients who underwent RPN by renal surgeons experienced in minimally invasive techniques at four academic institutions from June 2006 to March 2010. Patients were stratified into two groups: those with hilar lesions and those with nonhilar lesions. MEASUREMENTS Patient demographics, operative outcomes, and postoperative outcomes, including oncologic outcomes, were recorded. RESULTS AND LIMITATIONS Forty-one patients (9%) had hilar renal masses; 405 patients (91%) had nonhilar masses. There was no statistical differences in patient demographics except for larger median tumor size in the hilar cohort (3.2 cm vs 2.6 cm; p=0.001). The only significant difference in operative outcomes was an increase in warm ischemia times for the hilar group versus the nonhilar group (26.3±7.4 min vs 19.6±10.0 min; p=<0.0001). There were no differences in postoperative outcomes; however, there was a trend for increased risk of malignancy and higher stage tumors in the hilar lesion group. Final pathologic margin status was similar in both groups. Only one patient in the nonhilar group had evidence of recurrence at 21 mo. The study was limited by the lack of standard anatomic classification of renal tumors and the potential influence of the surgeons' prior robotic experience. CONCLUSIONS The data represent the largest series of its kind and strongly suggest that RPN is a safe, effective, and feasible option for the minimally invasive approach to renal hilar tumors with no increased risk of adverse outcomes compared with nonhilar tumors in the hands of experienced robotic surgeons.