The procedure uses ultrasound to generate shock waves that travel through the skin and body tissues until they hit the dense stones. The stones are crushed into tiny sand-like pieces that usually pass easily through the urinary tract. The shattered stone fragments may cause discomfort as they pass through the urinary tract. In such cases, the doctor may insert a small tube called a stent through the bladder into the ureter to help the fragments pass. This practice, however, has not proved to speed up passage of the stones in most cases and is not used routinely.
Recovery time is short, and most people can resume normal activities in a few days.
The most common complication is blood in the urine, which lasts for a few days after treatment. Bruising and minor discomfort due to the shock waves are common in the back or abdomen. Sometimes the stone is not completely fragmented with one treatment, and additional treatments may be required. It is more effective for patients with severe obesity and appears to be safe for the very elderly and the very young. It is also preferred over ESWL for stones that have remained in the ureter for more than four weeks.