[THE FACTORS THAT AFFECT THE DECISION TO PERFORM LAPAROSCOPIC PARTIAL NEPHRECTOMY FOR SMALL RENAL TUMOR].

(Objectives) Nephron sparing surgery (NSS) is strongly recommended for patients with T1a renal cell carcinoma (RCC) whenever surgically feasible. However, partial nephrectomy, particularly laparoscopic approach, remains underutilized in Japan compared to laparoscopic radical nephrectomy (LRN). In this study, we examined the safety and efficacy of laparoscopic partial nephrectomy (LPN) for T1a RCC compared to LRN. We also assessed the factors that affect the decision to perform LPN or LRN. (Patients and methods) From March 2001 to September 2014, 112 patients with T1a renal tumors received renal surgery at our institution. Of these, 100 patients (LPN: 36 patients, LRN: 64 patients) underwent laparoscopic surgery. Treatment outcomes including surgical and oncological outcomes among each approach were compared. In addition, multivariate analysis was performed to reveal the factors that affect the decision on surgical approach. (Results) The ratio of patients more than 75 years old and the RENAL nephrometry score were higher in LRN group than those in LPN group. Operating time was longer but renal function was well preserved in LPN group. Importantly, blood loss, intraoperative and postoperative complication rate, and oncological outcome (recurrence-free survival and overall survival) were similar in both groups. Multivariate analysis revealed that age (≥75 years old), high RENAL nephrometry score, operation period (before 2011), and the absence of Endoscopic Surgical Skill Qualification (ESSQ) in surgeon were independent predictive factors that select LRN. (Conclusions) Our data suggests that LPN for T1a renal tumor could be performed safely and the decision whether LPN or LRN were performed were associated with technical factors such as the presence of ESSQ or operation period, as well as patient's factor such as age and tumor factor such as tumor complexity.