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 (TM) 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.