The ureter is either of two tubes, 10 to 12 inches long, that carry urine from the kidneys to the bladder. Distal stones are usually found at the far end of the ureter, closer to the kidney. About 90% of urinary stones can be seen on X rays.

These investigators studied two first line approaches to distal ureteral stone removal: extracorporal shock wave lithotripsy (ESWL) and ureteroscopy or URS (passage of a viewing tube and crushing device up the ureter). They treated 80 patients with distal ureteral stones. Forty had stones smaller than 5 millimeters and 40 larger.

Following ureteroscopy, surgeons routinely placed a stent, a device to provide support for tubular structures. The researchers concluded that URS was superior to EWSL in: operating time, radiation time, stone clearance, and reoperative rate.

The differences between the two techniques proved more significant for smaller stones. The investigators saw the only drawbacks to URS use was stent placement in patients for 4 to 14 days, depending on the size of the stone, and dependence on the surgeon's skill or experience with the URS.