Use of the Assistent Guide Facilitates Ureteral Stent Placement in Robot-Assisted Pyeloplasty.

INTRODUCTION

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).

MATERIALS AND SURGICAL TECHNIQUE: 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.

DISCUSSION: 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.