Robot-assisted Partial Nephrectomy for Complex (PADUA Score ≥10) Tumors: Techniques and Results from a Multicenter Experience at Four High-volume Centers

Robot-assisted partial nephrectomy (RAPN) represents a widely accepted minimally invasive alternative to open and laparoscopic surgery for the treatment of clinically localized renal tumors. To assess the feasibility of RAPN in a contemporary series of patients with highly complex tumors (PADUA score ≥10) treated at four high-volume robotic surgery institutions. Data from a prospectively maintained multi-institutional database on patients subjected to RAPN between 2010 and 2017 were reviewed. For the scope of this analysis, only patients with highly complex renal tumors, defined as a PADUA score between 10 and 14, were included. RAPN was performed with the da Vinci Si or Xi surgical system (Intuitive Surgical, Sunnyvale, CA, USA) using novel technologies such as TilePro and near-infrared fluorescence imaging. Intraoperative, postoperative, surgical, and oncological outcomes were collected. Predictors of optimal surgical outcomes defined according to the Margin Ischemia and Complications binary system (absence of Clavien-Dindo >2 complications, warm ischemia time [WIT] <20 min, and absence of positive surgical margins) were determined using logistic regression models (LRMs). Overall, 255 patients with complex renal tumors were included. The mean operative time was 165 min and mean WIT was 18.6 min. Overall, WIT was longer than 20 min in 86 (33.7%) individuals, while a Clavien-Dindo >2 complication and positive surgical margins were observed in 13 (5.1%) and four (out of 211 patients with malignant histotypes; 1.9%) individuals, respectively. Optimal surgical outcomes were achieved in 158 (62.0%) patients. At a median follow-up of 28 mo, one (0.4%) local and two (0.8%) distant recurrences of the disease were observed. In multivariable LRMs, extremely complex tumors (PADUA score 12–13) were associated with an increased likelihood of not achieving optimal outcomes (odds ratio: 2.31; p = 0.024). Besides tumor complexity, male gender was also associated with a two-fold higher risk of not achieving optimal surgical outcomes (p = 0.029). In experienced hands, RAPN can be considered as an effective treatment option even in cases of complex renal lesions. However, increasing tumor complexity may affect the surgical outcomes in this highly selected patient population. We reported our multicentric experience with robot-assisted partial nephrectomy (RAPN) in patients with complex renal tumors. We demonstrated that, in experienced hands, RAPN is a feasible and safe treatment option even in such patients. Novel technologies applied to RAPN may further extend the indications without compromising the outcomes.