ABSTRACT Introduction:

Recent data suggest that robotic platform has become the most accessible minimal invasive surgery even for surgeons without previous training in laparoscopy. Laparoscopic partial nephrectomy (LPN) is a well-stablished procedure, however, with high level of complexity and long learning curve that limit its use.

Objective:

To describe safety, efficiency and learning curve of a single surgeon without previous experience in LPN to reach "TRIFECTA" at robot-assisted partial nephrectomy (RAPN).

Patients and Methods:

This is a retrospective study, with prospective data collection of 101 patients submitted to RAPN by a single surgeon. In order to analyze the learning curve, sample was chronologically divided in two phases: first phase: P1: 50 first patients, second phase: P2: 51 subsequent patients.

TRIFECTA was defined as:

ischemia time lower than 25 minutes, negative surgical margin and absence of severe complications (Clavien >2).

Results:

Mean age of patients was 54 years (SD=11.85), median tumor size was 32mm (SD=17) and surgery was performed with zero ischemia time in 33.6% of patients (29.8% at P1 and 40.9% at P2). Demographic data of patients were similar between both groups, except tumor size (P1=27.5mm vs. P2=35.3mm; p=0.02) and body mass index (BMI) (P1=26.6kg/m2 vs. P2=29kg/m2; p=0.03). Rate of bleeding, surgical time, presence of positive margin and peri-operatory surgical complications were similar in both phases. TRIFECTA was higher in P2 in relation to P1 (P1: 58% vs.

P2:

87.8%; p=0.002) and median time of hot ischemia was significantly lower at P2 (P1: 17.3 vs.

P2:

11.7; p=0.02).

At multivariate analysis independent factors related to TRIFECTA included:

chronological phase (OR 10.74; 95% IC: 1.63-70.53; p=0.013) and tumor size (OR 0.95; 95% IC: 0.91-0.99; p=0.024).

Conclusion:

RAPN seems to be safe and efficient with good functional and oncological results (TRIFECTA) since the beginning. Experience improvement was related to treatment of larger tumors, higher proportion of patients with zero ischemia and higher rate of TRIFECTA.