Introduction

Given the technical advantages offered by the robotic platform, there has been an upward trend in the utilization of robotic partial nephrectomy however little information exist on conversion from robotic partial nephrectomy (RPN) to radical nephrectomy (RN)._x000D_ Our aim was to identify the preoperative factors associated with conversion from RPN to RN, and to report the incidence of this event._x000D_

Methods

Using our institutional review board-approved database, we abstracted data on 1023 RPN cases performed at our center between 2010 and 2015. Standard and converted cases were compared in terms of patients and tumor characteristics and perioperative, functional, and oncological outcomes. Logistic regression analysis was used to identify predictors of radical conversion.

Results

The overall conversion rate was 3.1% (32/1023). The most common reasons for conversion were tumor involvement of hilar structures (n=8, 25%), Failure to achieve negative margin on frozen section (n=7, 21.8%), suspicion for advanced disease (n=5, 15.6%), and failure to progress (n=5, 15.6%). Patients requiring conversion were older (p<0.01) and had higher Charlson scores (p<0.01), including increased prevalence of CKD (p=0.02). Increasing tumor size (5 vs. 3.1 cm, p<0.01) and R.E.N.A.L score (9 vs. 8, p<0.01) also were associated with increased risk of conversion. Worse baseline renal function (OR 0.98 95% CI 0.96-0.99 p=0.04), high tumor size (OR 1.44, 95% CI 1.22-1.7, p<0.01), and increasing R.E.N.A.L score (p=0.02) were independent predictors of conversion. Compared to converted cases, standard RPN cases had similar short-term oncological outcomes but better renal functional preservation (p<0.01) at latest follow-up.

Conclusions

At a high-volume center, the rate of RPN conversion to RN is 3.1% including 2.2% of preoperatively anticipated nephrectomy cases. Increasing tumor size and complexity and poor preoperative renal function are the main predictors of conversion.

Funding

None