MECHANISMS OF GENESIS AND GROWTH OF CALCULI

The purpose of this discussion is to examine some of the stone-forming mechanisms at the basic level. An attempt is made to consider three persistent root questions: (1) What is the physicochemical mechanism by which stone material is synthesized or put together? A concept employing crystallization principles was suggested as an appropriate alternative to the usual view, which assigns to stone matrix a crucial position in the stone process. (2) How and where do stones start in a structurally normal urinary tract despite the obvious inference that the stone embryo is very small and easily expelled? Here the peculiar significance of the renal papilla was emphasized. (3) What explanation can be offered to account for so-called idiopathic stone disease? An analogy with stone triggering experiments was explored and speculatively an explanation offered in which a short-lasting triggering episode sets off papillary embryogenesis. Thereafter the embryo continues to grow, even though the urine is no longer unusually propitious for crystallization. This concept emphasizes the significance of fluctuations in urine concentration in the causation of urolithiasis. © 1968.