Does flexible ureteroscopy for kidney stones cause damage to the kidneys?

Flexible ureteroscopy (FURS) for kidney stone removal typically does not harm the kidneys. A flexible ureteroscope is inserted through the patient’s urethra and ureter into the kidney, where a laser is used to fragment the stones. The resulting stone fragments are usually passed spontaneously via the ureter and urine without causing renal injury. However, during laser lithotripsy, the ureteral mucosa may be affected—potentially leading to mucosal injury and edema. After surgery, patients are advised to drink plenty of fluids and urinate frequently to facilitate timely passage of the stone fragments.