Robotic-assisted transperitoneal nephron-sparing surgery for small renal masses with associated surgical procedures: surgical technique and preliminary experience.

Small renal masses (T1a) are commonly diagnosed incidentally and can be treated with nephron-sparing surgery, preserving renal function and obtaining the same oncological results as radical surgery. Bigger lesions (T1b) may be treated in particular situations with a conservative approach too. We present our surgical technique based on robotic assistance for nephron-sparing surgery. We retrospectively analysed our series of 32 consecutive patients (two with 2 tumours and one with 4 bilateral tumours), for a total of 37 robotic nephron-sparing surgery (RNSS) performed between June 2008 and July 2012 by a single surgeon (G.C.). The technique differs depending on tumour site and size. The mean tumour size was 3.6 cm; according to the R.E.N.A.L. Nephrometry Score 9 procedures were considered of low, 14 of moderate and 9 of hight complexity with no conversion in open surgery. Vascular clamping was performed in 22 cases with a mean warm ischemia time of 21.5 min and the mean total procedure time was 149.2 min. Mean estimated blood loss was 187.1 ml. Mean hospital stay was 4.4 days. Histopathological evaluation confirmed 19 cases of clear cell carcinoma (all the multiple tumours were of this nature), 3 chromophobe tumours, 1 collecting duct carcinoma, 5 oncocytomas, 1 leiomyoma, 1 cavernous haemangioma and 2 benign cysts. Associated surgical procedures were performed in 10 cases (4 cholecystectomies, 3 important lyses of peritoneal adhesions, 1 adnexectomy, 1 right hemicolectomy, 1 hepatic resection). The mean follow-up time was 28.1 months ± 12.3 (range 6-54). Intraoperative complications were 3 cases of important bleeding not requiring conversion to open or transfusions. Regarding post-operative complications, there were a bowel occlusion, 1 pleural effusion, 2 pararenal hematoma, 3 asymptomatic DVT (deep vein thrombosis) and 1 transient increase in creatinine level. There was no evidence of tumour recurrence in the follow-up. RNSS is a safe and feasible technique. Challenging situations are hilar, posterior or intraparenchymal tumour localization. In our experience, robotic technology made possible a safe minimally invasive management, including vascular clamping, tumour resection and parenchyma reconstruction.