Introduction: Nephron-sparing surgery (NSS) is of one of the most studied fields in urology due to the balancing between renal function preservation and oncological safety of the procedure. Aim of this short review is to report the state of the art of intra-operative ultrasound as an operative tool to improve localization of small renal masses partially or completely endophytic during robot-assisted partial nephrectomy (RAPN). Material and methods: We performed a literature review by electronic database on Pubmed about the use of intra-operative US in RAPN to evaluate the usefulness and the feasibility of this procedure. Results: Several studies analyzed the use of different US probes during RAPN. Among them some focused on using contrast-enhanced ultra sonography (CEUS) for improving the dynamic evaluation of microvascular structure allowing the reduction of ischemia time (IT). We reported that nowaday the use of intraoperative US during RAPN could be helpful to improve the preservation of renal tissue without compromising oncological safety. Moreover, during RAPN there is no need for assistant to hand the US probe increasing surgeon autonomy. Conclusions: The use of a robotic ultrasound probe during partial nephrectomy allows the surgeon to optimize tumor identification with maximal autonomy, and to benefit from the precision and articulation of the robotic instrument during this key step of the partial nephrectomy procedure. Moreover US could be useful to reduce ischemia time (IT). The advantages of nephron-sparing surgery over radical nephrectomy is well established with a pool of data providing strong evidence of oncological and survival equivalency. With the progressive growth of robot-assisted partial nephrectomy (RAPN) techniques, the use of several tools has been progressively developed to help the surgeon in the identification of masses and its vascular net. In this short review we tried to analyze the current use of intra-operative ultrasound as an operative tool to improve localization of small renal masses partially or completely endophytic during RAPN.
