Robot-assisted radical nephroureterectomy for upper urinary tract tumor: initial experience with the use of novel surgical robot system, hinotori

Background: The hinotori surgical robot system is a promising robotic platform that has been recently introduced into routine clinical practice. The aim of this study was to report our initial experience of robot-assisted radical nephroureterectomy (RANU) using hinotori.Methods: This study included a total of eight patients with upper urinary tract tumor (UUTT) who underwent RANU using hinotori via the transperitoneal approach. In this series, nephrectomy was initially performed at the kidney direction stage followed by distal ureterectomy and bladder cuff excision at the bladder direction stage without repositioning of patient or port. Lymphadenectomy was performed at either stage.Results: Median age, body mass index, and tumor diameter were 76 years, 21.7 kg/m2 , and 13 mm, respectively. Of eight patients, three were diagnosed with renal pelvic tumors and five with lower ureteral tumors. They underwent lymphadenectomy targeting the renal hilum plus para-aorta and the pelvis, respectively. All procedures in this series were completed without conversion to open surgery. Median operative time, time using the robotic system, estimated blood loss, and length of hospital stay were 230 minutes, 138 minutes, 23 mL, and 8 days, respectively. No major perioperative complication occurred. Pathological examinations of the tumors revealed seven urothelial carcinomas and one papilloma, the median number of resected lymph nodes was 13, and one patient was positive for both cancer margin and lymph node metastases. Conclusions: Despite being a small case series, this is the first study characterizing RANU using the hinotori surgical robot system. RANU was efficaciously and safely performed, resulting in the achievement of favorable perioperative findings.