[Urinary stones in Western Algeria: study of the composition of 1,354 urinary stones in relation to their anatomical site and the age and gender of the patients].

INTRODUCTION: The prevalence of urinary stones runs parallel with the socioeconomic and health level of populations. Few data are currently available concerning the characteristics of urinary stones in Algeria. Based on our recruitment of stones derived from the main teaching hospital urology departments of Western Algeria, we defined the stone profile in this region of North Africa and its changes in relation to previous data. MATERIAL AND
METHOD: A series of 1,354 stones derived from urology departments in Western Algeria was studied by IRTF spectroscopy. Analysis of the results concerned the crystalline composition and anatomical site of the stones and the age and gender of the patients. RESULTS AND DISCUSSION: Conventional surgery is the method of extraction most frequently used with 79.7% of operations contre 0.2% for extracorporeal lithotripsy. The male/female ratio has remained almost constant at 2.23. The anatomical site has changed with a predominance in the upper tract (77.4% of stones). The proportions of whewellite and weddellite have increased compared to our first series, from 48.1% to 50.3% and 13.1% to 16.7%, respectively, while phosphates decreased from 24.4% to 16.7%. The presence of struvite has not decreased over recent years, as 28.8% of stones contain this type of crystal. Anhydrous uric acid has slightly increased to 8.8% versus 6.2%. The proportions of ammonium urate and cystine have not changed (1.8% and 0.7%, respectively), but ammonium urate forms is less frequently the nucleus of stones than previously (2% versus 5.89%). The study of the nucleus showed that phosphates are predominant in 48.6% of cases versus 35.6% for oxalates. Carbapatite and struvite are more frequent in women, found in 50.8% and 6.7% of cases, respectively, than in man, found in 44.6% and 3.7% of cases, respectively. Calcium oxalate is predominantly found in the upper urinary tract (70.9%) rather than in the bladder (48.3%), regardless of gender. Calcium phosphate is more abundant in the upper tract of females with 23.7% of cases versus 10.7% in the bladder. It is equally distributed between the bladder and the upper tract in males (13.7% and 13.2%, respectively). Examination of the side affected by stones showed a predominance of the left side in both sexes.
CONCLUSION: Analysis of these data shows that urinary stones in Western Algeria are tending to evolve in the same direction as in industrialized countries, but urinary tract infection remais a frequent cause of stones.