URO-OXALIC NEPHRITIC LITHIASIS - SOME PAR TICULARITIES

In a paper published in 1974, it was reported that uro-oxalic stones a re found more often in subjects with group O than with group A blood t ypes although the proportions of these two blood types are approximate ly equivalent in the French population. The present work confirms thes e data, the ratio of group O to group A renal lithiasis being approxim ately 3 to 1. In a paper published in 1987, uro-oxalic stones were fou nd to occur preferentially on the left side: 84 on the left and 39 on the right. The present work confirms this notion since in 57 cases, st ones were bilateral in 2 cases, on the left in 39 and on the right in 16. Extra corporeal shock wave lithotripsy was performed in 40 of the 57 cases and showed that uro-oxalic stones are most resistant to shock -waves than the other types of stones, They are about as hard as calci um oxalate monohydrate stones or harder in certain cases: A mean of 3 865 shock-waves were required in the 40 cases of the uro-oxalic lithia sis treated with the HM3 Dornier device, while the mean number of shoc k-waves required for all types of stones in general Varies from 2 000 to 2 500. In 4 cases, 5 000 or 6 000 high power shock-waves (7 000 in one session and 9 500 in two sessions) had to be used to obtain a sati sfactory result. The calcium oxalate part of these stones is almost al ways composed of calcium oxalate monohydrate. The uric acid part is in general composed of anhydrous or bihydrated uric acid or red or yello w-red sodium urate. In the last series, white ammonium rate stones wer e spontaneously expelled whole or after lithotripsy fragmentation in p atients without any important infection. The proportion of uro-oxalic stones, compared with all nephritic stones, was in 1974 approximately 5% nearly identical to that of uric acid stones. In 1994, the proporti on of uro-oxalic stones reached 9.8% and the proportion of uric acid s tones fell to 2%. These observations raise important genetic, pathogen ic and therapeutic questions.