Robot-Assisted Laparoscopic Partial Nephrectomy for Tumors Greater than 4 cm and High Nephrometry Score: Feasibility, Renal Functional and Oncological Outcomes with Minimum 1 Year Follow-up

Objectives Minimally invasive robotic assistance is being increasingly utilized to treat larger complex renal masses. We report on the technical feasibility and renal functional and oncologic outcomes with minimum 1 year follow-up of robot-assisted laparoscopic partial nephrectomy (RALPN) for tumors greater than 4 cm. Materials and methods The urologic oncology database was queried to identify patients treated with RALPN for tumors greater than 4 cm and a minimum follow-up of 12 months. We identified 19 RALPN on 17 patients treated between June 2007 and July 2009. Two patients underwent staged bilateral RALPN. Demographic, operative, and pathologic data were collected. Renal function was assessed by serum creatinine levels, estimated glomerular filtration rate, and nuclear renal scans assessed at baseline, 3, and 12 months postoperatively. All tumors were assigned R.E.N.A.L. nephrometry scores ( http://www.nephrometry.com ). Results The median nephrometry score for the largest tumor from each kidney was 9 (range 6–11) while the median size was 5 cm (range 4.1–15). Three of 19 cases (16%) required intraoperative conversion to open partial nephrectomy. No renal units were lost. There were no statistically significant differences between preoperative and postoperative creatinine and eGFR. A statistically significant decline of ipsilateral renal scan function (49% vs. 46.5%, P = 0.006) was observed at 3 months and at 12 mo postoperatively (49% vs. 45.5%, P = 0.014). None of the patients had evidence of recurrence or metastatic disease at a median follow-up of 22 months (range 12–36). Conclusions RALPN is feasible for renal tumors greater than 4 cm with moderate or high nephrometry scores. Although there was a modest decline in renal function of the operated unit, RALPN may afford the ability resect challenging tumors requiring complex renal reconstruction. The renal functional and oncologic outcomes are promising at a median follow-up of 22 months, but longer follow-up is required.