Objective: To study the characteristics and components of staghorn calculi in southern Thailand.

Material and Method: 5,445 urolithiasis patients who underwent treatment in Songklanagarind Hospital between 1997 and 2000 were reviewed and 86 of them were included by the criteria of “complete staghorn” calculi. General data, laboratory data at presentation, and the component analysis was performed with infrared spectroscopy were analyzed.

Results: Forty-three men and 43 women were included in the present study, with a mean age of 55.5 years for men and 50.7 years for women. Uric acid was the most common component of staghorn calculi and 61.8% of the patients had hyperuricemia. Magnesium ammonium phosphate (MAP) was found in 11.6% of the calculi. A positive urine culture was found in 59.3% of the patients and the micro-organisms most frequently found were Corynebacterium sp and E. coli.

Conclusion: There was a significant higher incidence of staghorn calculi in women in comparison with urolithiasis patients in southern Thailand, and the most common component was uric acid.

Keywords: Staghorn calculi, Composition, Urinary tract infection