To study prospectively the risk factors and etiology of urolithiasis in all
stone patients aged <15 years admitted from 1991 to 1999 to the Arabkir ho
spital in Yerevan. Stones were obtained by surgery (64%), extracorporeal sh
ockwave lithotripsy (ESWL) (7%) or cystoscopic extraction (4%); 25% passed
spontaneously. All were examined by infrared spectroscopy, and spot urines
were analyzed chemically. 198 patients, 180 (68% males) with renal stones a
nd 18 (83% males) with primary bladder stones, were studied. Calcium oxalat
e (CaOx) was the predominant constituent in 62% of the kidney stones, follo
wed by struvite (17%), calcium phosphate (7%), uric acid (7%), ammonium aci
d urate (5%), and cystine (2%). Bladder stones contained CaOx in 72%, uric
acid in 22% and ammonium acid urate in 6% of patients. Etiology was obvious
ly metabolic in 5% and possibly metabolic in 26%. Twenty percent of stones
were infectious, and 19% were endemic (9% bladder and 10% kidney stones); 4
% were secondary to urinary stasis with malformation but no infection. Etio
logy in 26% remained unknown. Stone composition and metabolic etiology are
similar to that in central Europe and North America. In contrast, infectiou
s calculi and particularly endemic stones are still common, although becomi
ng less so now. Urolithiasis in Armenia thus reflects the transition from a
rural to an urban society.