[A CASE OF RETROPERITONEAL HEMORRHAGE CAUSED BY THE INSERTION OF A URETERAL ACCESS SHEATH. A RARE COMPLICATION ASSOCIATED WITH FLEXIBLE TRANSURETHRAL LITHOTRIPSY (fTUL)].

A 77-year-old man with a right kidney stone was admitted to our hospital. A ureteroscope was introduced into the ureter without dilation under direct vision. We then performed flexible transurethral lithotripsy (f-TUL) using a ureteral access sheath and successfully fragmented the stone and extracted almost all the stone fragments without any complications. Just 3 hours after the operation, he suddenly developed right abdominal pain with a decrease in hemoglobin. A CT scan showed a retroperitoneal hemorrhage around the lower ureter. We herein describe a rare complication associated with flexible transurethral lithotripsy.