This procedure is the treatment of choice for stones larger and are in a location that does not allow effective use of shockwave lithotripsy or cause a blockage that is so severe that the kidney is obstructed. In this procedure, the urologist has a tube inserted into the flank area into the kidney and then uses an instrument called a nephroscope to locate and remove the stone. Larger stones are broken with an ultrasonic probe that breaks the stone and vacuums the fragments from the kidney. One advantage of this procedure is that the stone fragments are removed directly at the time of the procedure. Generally, the patients stay in the hospital for one night after the procedure and they have a small tube left in the kidney for a week after the surgical procedure. Most patients can resume light activity in 1-2 weeks after the procedure.