Physical characteristics of percutaneous nephroscopes.

Flexible and rigid endoscopes are being used in the kidney with increasing frequency for endourologic procedures such as stone removal. The available instruments have different physical characteristics, a knowledge of which is important in proper instrument selection. We compared irrigant flow rates and the angles and areas of vision of the Olympus, ACMI, and Pentax flexible endoscopes and the Storz, Wolf, and Thackray rigid instruments. These findings and their implications for instrument use are described.