Robotic partial nephrectomy: A promising treatment option for T1b and complex renal tumors?

Only few studies reporting the oncological, peri-operative and functional outcomes of robot-assisted partial nephrectomy (RAPN) performed for T1b or complex renal tumors are currently available in literature. We read with interest the recently published paper by Masson-Lecomte and collaborators, and we congratulate for the relevance of this study.1 This is one of the largest, multi-institutional study evaluating the operative and oncologic outcomes of 54 consecutive RAPN for tumors over 4 cm. The tumor complexity was evaluated by the R.E.N.A.L. nephrometry score, which classify the kidney tumors into three different risk categories, according to their anatomical features.2 The median R.E.N.A.L. score of the cohort of patients was 7 (IQR: 4–10), thus reflecting an intermediate surgical complexity of the tumors. The median warm ischemia time (WIT), operative time and blood loss were 23 min, 180 min and 100 ml, respectively. Post-operative complications were observed in 9 (16.7%) patients, of which one third were major according to the Clavien-Dindo classification. Positive surgical margins were observed in 3 cases (5.5%), and a statistically significant impairment of the glomerular filtration rate (GFR) was observed after surgery (p = 0.018). At a median follow-up of 23 months, no local recurrences were found, and only 2 patients experienced distant metastases. 1 The peri-operative, functional and oncological outcomes emerged from this paper are comparable to those currently reported in a recent review showing the effectiveness, feasibility and safety of RAPN when performed for cT1b or complex renal tumors. 3 In details, the operative time, the WIT and the risk of peri-operative complications were found to be higher than those observed after RAPN for cT1a or less challenging procedures, even if, in the hands of experienced surgeons, no concerns potentially limiting the diffusion of robotic partial nephrectomy for large renal masses have been described. Unfortunately, studies comparing robotic surgery to open or laparoscopic partial nephrectomy for the management of large renal cancers are not yet available. However, the intra-operative, oncological and functional outcomes of RAPN for complex cT1a are absolutely promising, 3 and similar to those observed after open partial nephrectomy for complex or hilar cT1a tumors. 4 We believe that this study add new knowledge in this field, and can contribute in enhancing the role of robotic surgery in expanding the indications for the conservative treatment of large or complex renal tumors.