A More Effective Method of in vitro Urinary Stone Disintigration Using the Nd:YAG Laser

Abstract

A tube system for urinary stone disintigration which contains as essential parts a water chanal and a Nd:YAG laser beam is presented.The calculi are sucked to this system by a pump, thus being in direct contact with the tube in 90% of the time. The entrance of the tube system has two functions: a) the laser beam leaves the tube via this entrance and hits the calculus and b) the fragments from the calculus splint off and are immediately sucked to the water chanal via the entrance of the tube system. Thus the stone is completely disintigrated step by step. Only fragments equal in size with the entrance or smaller are sucked to the water chanal. By variation of the entrance size of the tube system, the fragment size of the urinary calculi can be determined before starting disintigration. The method described by us allows stone disintigration into very small uniform particles (100 – 200 μm, intensity of laser radiation I= 10⁹ W/cm²).