LAUSR

PURPOSE To evaluate the clearance of metal particles produced and released in the pelvicalyceal system (PCS) during percutaneous nephrolithotomy (PCNL) with the use of the Swiss Lithoclast® Trilogy dual-energy (EMS Urology, Nyon, Switzerland) lithotripter. METHODS An experimental in vivo study and a clinical investigation of case series were conducted. An in vivo porcine model with 2 pigs for lithotripsy (after inserting artificial stones into the collecting system) and 2 pigs for submucosal injection of metal particles (provided by the manufacturer of Trilogy) was conducted. Porcine kidney histology for metal leftovers was analyzed immediately or 2-weeks after the surgery. A prospective observational study design included 10 consecutive patients treated with conventional 30Fr PCNL or with 22Fr mini-PCNL technique. Only the patients with the confirmed metal particles in the PCS during the initial PCNL and the need for additional retrograde intrarenal surgery (RIRS) over a period of 2-4 weeks were selected. The presence of metal particles was evaluated during the second endoscopic surgery. RESULTS The generated metal particles during PCNL and the submucosally injected particles were not found macroscopically 2 weeks postoperatively in porcine models. No pathological changes such as foreign body granuloma or inflammation were found. Similarly, no metal particles were observed during the second look endoscopy (n=10). CONCLUSION Metal particles observed endoscopically using Trilogy lithotripter are cleared with no pathological evidence of tissue damage from the metal particles 2 weeks after the procedure. Thus, the intra-operative release of any particle by the Trilogy should not raise any safety concerns.