Feasibility of Laser Lithotripsy for Midsize Stones Using Robotic Retrograde Intrarenal Surgery System easyUretero in a Porcine Model.

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 calices. 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 s/stone vs 234.5 ± 102.5 s/stone, p  = 0.02; 41.5 ± 0.5 s/stone vs 79.3 ± 8.1 s/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 s/stone vs 284.8 ± 112.3 s/stone, p  = 0.08; 86.0 ± 30.5 s/stone vs 84.1 ± 21.4 s/stone, p  = 0.92). All stones were removed. Grade 1 ureteral and renal injuries occurred in both manual RIRS and robotic RIRS. Conclusions: The laser lithotripsy using the easyUretero robotic system is safe and feasible in a porcine model, even for less-experienced surgeons.