In vitro and in vivo experiences with ureterorenoscope by Gelet.

Using ureterorenoscopes with unidirectional flow, the urologist faces a conflict between a good view on one hand and high pressure in the ureter and the pelvic collecting system of the kidney on the other hand. The ureterorenoscope designed by Gelet, which has continuous (bidirectional) flow and separate irrigation and working channels, was compared with the instrument by Pérez-Castro, which has a common irrigation and working access. The features investigated were optical quality, flow-irrigation characteristics, and handling. The latest generation of ureterorenoscopes provides small total diameters because of minimized working channels and fiberoptic image and light transmission. These semirigid instruments combine the features of flexible endoscopes and traditional ureterorenoscopes. The Gelet instrument offers continuous flow, achieved by separation of the irrigation and working channel, and provides a good view even when working instruments are inserted. The additional outlet channel prevents high pressure in the ureter and renal pelvis and offers another access for instrumentation, if necessary, which means maximum safety for the patient. Because the connection of camera and light source on a flexible system is separated from the instrument, ureterorenoscopy is a more convenient procedure for the urologist.