LAUSR

PURPOSE To test the safety and feasibility of laser lithotripsy for midsize renal stones using a newly developed robotic retrograde intrarenal surgery (RIRS) system (easyUretero) in a porcine model. MATERIALS AND METHODS Three urologic surgeons representing three different RIRS experience levels (beginner, intermediate, and expert) participated. Four female pigs (aged 6 months) underwent manual or robotic RIRS. Under general anesthesia, a nephrostomy tract was created ventrally, and calcium stones (diameter, 1.0-1.5 cm) were inserted at renal calyces. For manual RIRS, surgeons operated a flexible ureteroscope. For robotic RIRS, the ureteroscope was attached to the robotic slave device. The Auriga XL™ Holmium laser was used for lithotripsy. Lasering and stone retrieval time were measured. Kidneys and ureters were inspected for injury at the end of each session. RESULTS For the expert, both lasering and stone retrieval by manual RIRS were quicker than by robotic RIRS (22.8 ± 11.0 vs 234.5 ± 102.5 sec/stone, p = 0.02; 41.5 ± 0.5 vs 79.3 ± 8.1 sec/stone, p = 0.02). For the intermediate and beginner, lasering and stone retrieval times were not significantly different between manual and robotic procedures (127.8 ± 93.2 vs 284.8 ± 112.3 sec/stone, p = 0.08; 86.0 ± 30.5 vs 84.1 ± 21.4 sec/stone, p = 0.92). All stones were successfully removed. Grade 1 ureteral and renal injuries occurred in both manual RIRS and robotic RIRS. CONCLUSIONS Laser lithotripsy using the easyUretero robotic system is safe and feasible in a porcine model, even for less-experienced surgeons.