[Flow technic analysis of the pyelocalyceal system with regard to urinary calculi formation. I. Theoretical considerations].

The formation of urinary calculi is usually interpreted chemico-crystallographically. However, hydrodynamic examinations, both theoretical and experimental, show that unfavourable flow conditions in the pelvi-calyceal system may allow pathogens to remain in the appropriate zones for the length of time necessary for growth. Some light is shed on a new factor which has so far been ignored. Part I deals with theoretical considerations, while part II gives information on preliminary experiments using statistical models.