fig1

Figure 1. Patient positioning and port configuration for left-sided UTUC. (A) The patient was positioned in a lateral decubitus position with a 70° tilt; (B) A 5-cm incision is made along the lateral border of the rectus abdominis, with the inferior edge aligned with the umbilicus; (C) A multichannel single-site port is placed through this incision. An additional 8-mm incision is created 2 cm cranial to the ASIS to place a trocar for the robotic fourth arm, providing bowel/peritoneal retraction to reduce visual interference; this accessory port is optional and used at the primary surgeon’s discretion; (D) The 12-mm camera is assigned to the platform’s 12-o’clock channel and maintained in the 30° “up” orientation throughout. The 6-o’clock 12-mm channel serves as the assistant port. The 3- and 9-o’clock channels dock the working robotic arms: right arm monopolar curved scissors, left arm Cadiere forceps. UTUC: Upper tract urothelial carcinoma; ASIS: anterior superior iliac spine.