NEPHROSCOPY WITH CARBON DIOXIDE IN COMBINATION WITH LAPAROSCOPY IN THE TREATMENT OF URINARY STONES Alejandro Garcia-Segui, Eduardo Bercowsky, Ignacio Gómez, Ramón Gibernau, Miguel Gascón Hospital General Mateu Orfila. Department of Urology. Menorca- Spain INTRODUCTION AND OBJECTIVE. Most of the urinary tract stones can be treated effectively with no invasive or endourological procedures. Nevertheless, in selected patients with complex stones or anatomical abnormalities a laparoscopic approach in combination with endoscopic procedures could be performed. In theses cases, the use of irrigation fluid during the nephroscopy may be a pitfall because, in an opened renal pelvis, large amounts of fluid are collected in the peritoneal cavity. The use of carbon dioxide (CO2) to insufflate the collecting system may to facilitate nephroscopy during laparoscopic pyelolithotomy. We present a video shows our experience in laparoscopic management of urinary lithiasis in combination with nephroscopy with CO2. METHODS. Twenty-one patients underwent laparoscopic surgery in treatment for urinary stones. Four of them underwent laparoscopic surgery combinated with nephroscopy with CO2. The indications to perform laparoscopy in urolithiasis are: concomitant ureteropelvic junction (UPJ) stenosis, stones in ectopic kidney, impacted ureteral stones larger than 1.5cms, failure of other procedures. Our video shows two interesting cases: first patient was a 58y-o male with multiple calculous and UPJ stenosis was treated by nephrolithotomy + nephroscopy flexible with CO2 + dismembered pyeloplasty, second patient was a 47y-o female with a large impacted stone located in the proximal ureter that migrated to the renal pelvis during laparoscopic ureterolithotomy, and required nephroscopy with CO2. We performed surgeries using the 3 or 4-port transperitoneal technique. RESULTS. The median age was 45y-o, 75% were male patients. The mean operative time of nephroscopy was 25minutes (range 15-48). The mean bloodloss was inestimable. The median hospital stay was 2,8days (range 1-7). There were no complications. CONCLUSIONS. Nephroscopy using CO2 to inflate the collecting system during laparoscopic pyelolithotomy, is a safe and secure trick that allows excellent vision, that facilitates stone removal and avoids the complications caused by leakage of irrigation fluid.