Robotic flexible ureteroscopy for renal calculi: initial clinical experience.

PURPOSE

We report what is to our knowledge the initial clinical experience with remote robotic ureterorenoscopy and laser lithotripsy for renal calculi using a novel flexible robotic system.

MATERIALS AND METHODS

After institutional review board approval and informed consent 18 patients with renal calculi underwent flexible robotic ureteroscopy. Study inclusion criteria were 5 to 15 mm renal calculi. Patients with ureteral calculi or obstruction, uncontrolled infection, renal insufficiency or solitary kidney were excluded from analysis. The flexible robotic catheter system was manually introduced into the renal collecting system over a guidewire under fluoroscopic control. All intrarenal maneuvers, including stone relocation and fragmentation into 1 to 2 mm particles, were done exclusively from the remote robotic console.

RESULTS

All procedures were technically successful without conversion to manual ureteroscopy. Mean stone size was 11.9 mm, mean robot docking time was 7.3 minutes, mean stone localization time was 8.7 minutes, mean total robot time was 41.4 minutes and mean total operative time was 91 minutes. The mean visual analog scale rating on a scale of 1-worst to 10-best was 8.5 for robotic control, 9.0 for stability and 9.2 for fragmentation ease. There were no intraoperative complications. Postoperative complications included transient fever in 2 cases and temporary limb paresis in 1. One patient required secondary percutaneous nephrolithotomy for residual stone. Based on computerized tomogram/excretory urogram the complete stone clearance rate at 2 and 3 months was 56% and 89%, respectively. At 3 months all patients had stable renal function and unobstructed drainage.

CONCLUSIONS

We present a novel flexible robotic platform for retrograde ureteroscopic treatment for intrarenal calculi. Initial experience is encouraging.