Robotic Partial Nephrectomy for Clinical Stage T1b Tumors: Intermediate Oncologic and Functional Outcomes

Despite the increased adoption of elective nephron-sparing surgery for T1 renal masses, controversy remains regarding the most appropriate management of clinical T1b or greater (> 4 cm) renal lesions. The available literature specifically investigating the use of robotic partial nephrectomy for these larger renal masses is limited to a few observational studies. In our experience, robotic partial nephrectomy for renal tumors > 4 cm is a safe procedure with excellent intermediate-term oncologic outcomes and good preservation of renal function. Objective: The objective of this study was to examine our intermediate oncologic and functional outcomes of robotic partial nephrectomy for clinical T1b tumors. Partial nephrectomy has become the gold standard of treatment for small renal masses. Recently, indications for minimally invasive partial nephrectomy have extended to larger and more complicated renal masses in some centers. Materials and Methods: Between July 2008 and September 2013, 241 robotic partial nephrectomies were performed at our institution, including 46 for clinical >= T1b tumors. We reviewed the intermediate-term functional and oncologic outcomes of this cohort of patients. Results: Of the 46 patients, the median age was 55.5 years ( interquartile range [IQR], 51-68 years) with a median body mass index of 31.6 (IQR, 27.4-38.9), tumor diameter of 5.0 cm (IQR, 4.1-5.2 cm), and RENAL nephrometry score of 7.1 (range, 5-11). Renal cell carcinoma was confirmed in 35 patients, and 11 patients had benign pathology. There was 1 patient with an established positive margin and 2 patients had a focal positive margin. At a median follow-up of 24.3 months (range, 2.3-61.1 months), the overall, recurrence-free and cancer-specific survival was 97.1%, 97.1%, and 100%, respectively. No patient progressed to dialysis postoperatively and there was no significant difference between preoperative and postoperative serum creatinine or estimated glomerular filtration rate using the Modification of Diet in Renal Disease equation. Conclusion: Because of the many adverse medical effects of chronic renal insufficiency, the indications for partial nephrectomy are expanding at many institutions. We demonstrated that robotic partial nephrectomy is a safe and efficacious procedure for the treatment of T1b renal tumors with excellent intermediate oncologic and functional outcomes.