Spectrum of stone composition: structural analysis of 1050 upper urinary tract calculi from northern India.
BACKGROUND
The purpose of the present paper was to study the spectrum of stone composition of upper urinary tract calculi by X-ray diffraction crystallography technique, in patients managed at All India Institute of Medical Sciences.


METHODS
Between 30 April 1998 and 31 March 2003, a total of 1050 urinary calculi (900 renal, 150 ureteric) were analyzed. The stone fragments were collected after extracorporeal shock-wave lithotripsy, or retrieval by endoscopic (percutaneous nephrolithotomy, ureterorenoscopy), laparoscopic and various open surgical procedures. The structural analysis of the stones was done using X-ray diffraction crystallography.


RESULTS
Four types of primary and three secondary X-ray diffraction patterns were obtained. The primary patterns were as follows. Pattern A, well organized crystalline structure; pattern B, moderately organized crystalline structure; pattern C, poorly organized crystalline structure; pattern D, very poorly organized crystalline structure. The three secondary patterns mainly highlighted the mixed variety of stones. These patterns were further analyzed and compared with standard X-ray diffraction (powder) photographs. Of the 1050 stones analyzed, 977 (93.04%) were calcium oxalate stones, out of which 80% were calcium oxalate monohydrate (COM) and 20% were calcium oxalate dihydrate (COD). Fifteen were struvite (1.42%) and 19 were apatite (1.80%). Ten were uric acid stones (0.95%) and the remaining 29 (2.76%) were mixed stones (COM + COD and calcium oxalate + uric acid, calcium oxalate + calcium phosphate, and calcium phosphate + magnesium ammonium phosphate). A total of 89.98% of staghorn stones were made of oxalates (COM/+COD) and only 4.02% were struvite.


CONCLUSIONS
Urinary stone disease in the Indian population is different from that in Western countries, with a larger percentage of patients having calcium oxalate stones, predominantly COM. Also, the majority of staghorn stones (89.98%) were made of oxalates.
Ansari
Mohd S
MS
Department of Urology, All India Institute of Medical Science, New Delhi, India. ansarimsa@hotmail.com
Gupta
Narmada P
NP
Hemal
Ashok K
AK
Dogra
Premnath N
PN
Seth
Amlesh
A
Aron
Monish
M
Singh
Tej P
TP
D000293:Adolescent; D000328:Adult; D000368:Aged; D001031:Apatites / Q000032:analysis; D002129:Calcium Oxalate / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D018360:Crystallography, X-Ray; D005260:Female; D006801:Humans; D007194:India; D017616:Magnesium Compounds / Q000032:analysis; D008297:Male; D008875:Middle Aged; D010710:Phosphates / Q000032:analysis; D033362:Powder Diffraction; D000069877:Struvite; D014527:Uric Acid / Q000032:analysis; D014545:Urinary Calculi / Q000737:chemistry* / Q000648:ultrastructure*
D001031:Apatites; D017616:Magnesium Compounds; D010710:Phosphates; D002129:Calcium Oxalate; D014527:Uric Acid; D000069877:Struvite