Clinical exploration of flexible ureteroscopy combined with holmium laser and intraoperative ultrasound localization for the treatment of stones in non-communicating calyceal diverticula: a single case report

Objective To investigate the value of intraoperative multimodal localization strategies in managing non-communicating calyceal diverticulum stones without preoperative definitive diagnosis in a single clinical case. Methods A 48-year-old female with a history of open renal stone surgery and cesarean section was enrolled in this single case study. Preoperative CT revealed a calcified lesion (1.5 × 1.2 cm, CT value 1,235 HU) at the right upper renal pole but failed to identify the diverticular structure. Intraoperative exploration identified a ureteral orifice ectopically located on the right posterior bladder wall (23 mm deviation from midline). An innovative “three-step localization protocol” was implemented: 1. CT-anatomical landmark spatial co-registration, 2. Guidewire advancement with tactile feedback validation, 3. Real-time ultrasonographic confirmation of guidewire tip positioning. A 10/12Fr ureteral access sheath was pre-placed in the right ureter to establish a stable operative channel, facilitate irrigation and suction, and reduce ureteral mucosal injury during the surgical procedure. Diverticular neck incision was performed using holmium laser (200 μm fiber, 0.8J/20 Hz) for channel creation, followed by stone fragmentation under negative-pressure suction system guidance. Results The procedure was completed in 90 min with negligible blood loss (<10 mL). Intraoperative ultrasonography confirmed complete stone clearance. No postoperative complications or recurrence was observed during follow-up. Conclusion Multimodal localization technique achieved effective and precise surgical navigation for the non-communicating calyceal diverticulum in this single case. This approach combines the advantages of natural orifice preservation with controlled infection risk and minimized hemorrhagic complications, and may provide a valuable clinical and technical reference for cases with atypical anatomy and inconclusive preoperative imaging.