[Whewellite and weddellite: toward a different etiopathogenesis. The significance of morphological typing of calculi].

From 3000 urinary calculi analysis, a morphological classification allowed us to appoint 7 structural types of oxalate stones, dependent on whewellite or/and weddellite. We observed evidence for correlations between biological data and these structural types, mainly between types I and hyperoxaluria, types II and hypercalciuria, types II + IV or IV and hyperparathyroïdism, as well as between whewellite and hyperuricuria. We determined in vitro calcium and oxalate concentrations ranges to crystallize various hydrate forms of calcium oxalate and we observed that whewellite form is almost the only one fitted for crystallizing in renal papilla. From this various data, it results that, in vivo, whewellite is dependent on oxalate concentration whereas weddellite is rather dependent on calcium concentration. Otherwise, differences in occurrence of morphological types of oxalate calculi were observed as a function of the patient' sex, the urinary tract localisation of calculi, or the crystalluria.