Saki Kobayashi, Yutaro Sasaki, Fumiya Kadoriku, Kei Daizumoto, Ryotaro Tomida, Yoshito Kusuhara, Kunihisa Yamaguchi, Tomoya Fukawa, Yasuyo Yamamoto and Junya Furukawa : Renal Pelvic Hematoma Following Robot Assisted Pyeloplasty: Two Case Reports, Asian Journal of Endoscopic Surgery, 19, 1, e70234, 2026.
(Summary)
Renal pelvic hematoma is an uncommon but important complication after robot-assisted pyeloplasty (RAP), with few reports in the literature. Here, we report two cases of renal pelvic hematoma following RAP: A 9-year-old girl (Case 1) and a 25-year-old man (Case 2), both diagnosed with left ureteropelvic junction obstruction. Both underwent transperitoneal Anderson-Hynes pyeloplasty using 5-0 absorbable monofilament sutures. Postoperative imaging revealed renal pelvic hematoma in each case. Both patients remained hemodynamically stable and were managed conservatively. In Case 1, the hematoma and urine were aspirated through a 6 Fr ureteral catheter, whereas in Case 2, symptoms resolved spontaneously. Follow-up imaging demonstrated preserved renal function and improvement of hydronephrosis in both cases. Renal pelvic hematoma after RAP is rare but can be managed conservatively in stable patients. Careful intraoperative hemostasis and awareness of this complication are essential to ensure favorable outcomes.
Saki Kobayashi, Masayuki Takahashi, 西山 美月, Yutaro Sasaki, Tomoyo Hara, Itsuro Endo and Junya Furukawa : 小児期に右副腎褐色細胞腫摘出後,妊娠時に対側発症が判明しVon Hippel-Lindau病の診断に至った1例, Japanese Journal of Pediatric Urology, 34, 1, 75-79, 2025.
3.
Yutaro Sasaki, Saki Kobayashi, Kei Daizumoto, Fumiya Kadoriku, Marika Atagi, Tetsuhiro Yano, Mitsuki Nishiyama, Ryoei Minato, Keito Shiozaki, Ryotaro Tomida, Yoshito Kusuhara, Kunihisa Yamaguchi, Tomoya Fukawa, Yasuyo Yamamoto and Junya Furukawa : Use of the Assistent Guide Facilitates Ureteral Stent Placement in Robot-Assisted Pyeloplasty., Asian Journal of Endoscopic Surgery, 18, 1, e70178, 2025.
(Summary)
In robot-assisted pyeloplasty, intraoperative placement of a double-J ureteral stent (DJ stent) is an essential step to ensure ureteral patency and anastomotic healing. However, the procedure can be technically demanding because of limited tactile feedback and the need for precise coordination between the console surgeon (CS) and the patient-side surgeon (PSS). To address these challenges, we applied the Assistent guide (UMIHIRA Co. Ltd., Kyoto, Japan), originally developed for robot-assisted intracorporeal ileal conduit diversion. The device is a stainless-steel instrument with a blunt tip and side hole, accommodating all stent sizes and insertable through a 5-mm trocar. During RAPP, the PSS advances the guide through the trocar to the ureteral anastomosis, the CS inserts the guidewire under direct vision, and the PSS advances the DJ stent antegrade along the guidewire. The CS provides countertraction to stabilize the ureter. Since August 2022, six patients underwent RAPP using this technique. Stent placement was successful in all cases without complications such as stent damage, malpositioning, or ureteral injury. The PSS reported smooth handling and reliable torque transmission compared with conventional methods. The Assistent guide costs approximately ¥80 000 per device and is reusable. Although limited by sample size and single-institution experience, this technique provides a practical solution to a technically challenging step in RAPP. Further multi-institutional evaluation is warranted to confirm safety, efficacy, and broader applicability.
Ryotaro Tomida, Saki Kobayashi, Ryoei Minato, Keito Shiozaki, Kei Daizumoto, Yutaro Sasaki, Yoshito Kusuhara, Tomoya Fukawa, Yasuyo Yamamoto, Kunihisa Yamaguchi and Junya Furukawa : Prognosis after partial versus radical nephrectomy in patients with cT1 non-clear cell renal cell carcinoma, The 63rd Annual Meeting of Japan Society of ClinicalOncology, Oct. 2025.