Robot-assisted radical prostatectomy using the novel hinotoriTM surgical robot system: initial experience and operation learning curve at a single institution.

Abstract

The hinotoriTM surgical robot system (HSRS) is the first made-in-Japan robotic system used for radical prostatectomy. Here, we report initial results and describe our learning curve (skill development) implementing robot-assisted radical prostatectomy using HSRS (h-RARP). Between November 2021 and December 2022, 97 patients who underwent h-RARP at our institution were enrolled in this study. We retrospectively evaluated the surgical outcomes of the initial cases using h-RARP, comparing those of RARP using da Vinci surgical robot system (d-RARP) in our institution. Furthermore, the learning curves of two surgeons with the highest number of h-RARP were analyzed. Patients treated by each surgeon were categorized into two groups: 1-15 cases (earlier group) and >15 cases (later group). Preoperative patient characteristics, operation parameters, and complication rates were compared between the two groups. In terms of surgical outcome, h-RARP was comparable to d-RARP. The procedures performed by the HSRS were successfully completed in all cases. There was no complication of grade 3 or higher. Comparing the two surgeons, surgeon 1, who had performed 40 d-RARP procedures, had time using robot system of the later group that was significantly shorter than that of the earlier group. However, for surgeon 2 with more than 100 d-RARP procedures, there was no statistically significant difference in time using robot system between groups. Other parameters showed no difference between earlier and later groups for the two surgeons. Our results show that surgical outcomes of h-RARP are comparable to those of d-RARP during the initial experience of clinical application. In addition, the surgeons' learning curves for the total RARP experience suggest that the experience of d-RARP can carry over to performance using the novel HSRS.