Correlations between crystalluria and composition of calculi
Kaid-Omar, Z.; Daudon, M.; Attar, A.; Semmoud, A.; Lacour, B.; Addou, A.
Progres en Urologie Journal de l'Association Francaise d'Urologie et de la Societe Francaise d'Urologie 9(4): 633-641
1999
ISSN/ISBN: 1166-7087 PMID: 10555214 Document Number: 502530
The successful fragmentation of kidney stones by means of extracorporeal shock wave lithotripsy partly depends on stone composition. In case of incomplete or coarse fragmentation, multiple urological procedures following ESWL may be necessary for removal of obstructive fragments. It is difficult to be sure that a given stone will be successfully destroyed. X-ray examinations before treatment are useful to classify calculi as calcium stones or not. Nevertheless, such investigations are often not sufficient to identify the main crystalline phases which form the stone and that can make it either resistant or friable to ESWL. The aim of this study was to compare crystalluria and stone composition in patients with kidney calculi. Seventy-five untreated patients (54 males, 21 females) were included. Their first morning urine was collected three days before surgical removal of the stone. Urine samples were kept at 4 degrees C during 48 hours before examination. Crystalluria occurred in 97.3% of urine specimens. Weddellite was the most frequent crystalline species found in urine (66.2%), followed by carbapatite (33.1%) and whewellite (23.1%). When compared to stone composition, crystalluria was mainly made of weddellite in urines from 68% of patients with weddellite-rich calculi. Stones from patients presenting with whewellite crystals in urine were mainly composed of whewellite in 88.9% of cases. Struvite stones were associated with struvite and carbapatite crystalluria in 85.7% of cases. Crystalluria studies could be of clinical interest to predict the main crystalline phase of calcium-containing stones in order to define the best procedures for stone removal.