Delivery of low ureteric stones with the Zeiss indwelling probe.

Endoscopic removal of stones by means of the indwelling Zeiss probe was attempted in 67 patients with low ureteric stones and in one with a pelvic stone. This was successful in 48 of the 53 patients in whom the probe passed the stone. The delivery of low ureteric calculi by the indwelling loop catheter has a high success rate and few of the serious complications seen with the rigid extractors, whose use should be restricted to stones lodged in the intramural ureter and measuring less than 4 mm in diameter.