The Zeiss Loop and the Placement of Indwelling Ureteric Catheters

Abstract

The idea of hastening the passage of ureteric stones by some form of probe or by the injection of liquid is as old as cystoscopy itself. A number of ingenious instruments have been described for this purpose, but they are not enumerated here since the majority are now only of historical interest. The decisive contribution was made by Zeiss (1939) who described the use of his loop catheter in encircling and extracting ureteric calculi. Most metal stone extractors are based on a different principal, e.g., Böhringer’s dilator and extractor, the Johnson basket, so popular in America, and more recently the Dormia basket.