Methods and Results of Conservative Expulsion of Urinary Calculi

Abstract

Consideration of the pathophysiology of the transit of a urinary calculus is a prerequisite to achieve successful expulsion of the urinary calculus by medication. Stone incarceration leads to local stretching and ischemia of the ureteral wall. This elicits acute pain and colic. If urinary stasis occurs, then there is additional pain from renal congestion. In the context of the viscero-visceral reflex or of the axonal reflex and the central counter-regulation via the sympathetic nervous system, the frequency of peristaltic contractions rises with simultaneous reduction of their amplitude. If the urinary stasis is maintained because of incarceration of the calculus, especially from the stone-fixing mucosal edema that occurs immediately, then only frequent wave movements can be discerned with low, ineffective amplitude. The effective filtration pressure for urinary calculus expulsion is also lacking. Only a relief of pressure will restart ureteral peristalsis. The intestinal paresis often observed as a result of ureteral colic also results from this sympathicotonic reaction.