Chemical composition of kidney stones obtained from a cohort of Sri Lankan patients

Introduction

Evaluating the composition of kidney stones is important for the treatment and prevention of nephrolithiasis.

Objectives

The aims of our study were to determine the composition of the renal stones in a cohort of Sri Lankan patients and to compare the composition of staghorn calculi with non-staghorn calculi.

Methods

Kidney stones removed from adult patients were analysed using chemical methods. Patients residing in different climate zones of Sri Lanka were analysed separately and comparisons made.

Results

A total of 50 renal stones from adults (male: female = 2.6:1) were included in the study. There were 21 staghorn calculi. The male to female ratio among patients with staghorn calculi was 3.2:1. There was no statistically significant difference in distribution of staghorn calculi and non-staghorn calculi among males (p=0.17) and among females (p=0.06). Oxalate stones constituted 86% of renal stones. Ten percent were mixed stones. Phosphate and struvite calculi contributed 2% each. Even among staghorn calculi, 76% were oxalate stones. There was no statistically significant difference between contents of staghorn and non-staghorn calculi. The composition of stones in three climatic zones of Sri Lanka was similar except for phosphorus.

Conclusion

The majority of renal stones (86%) in Sri Lanka are calcium oxalate stones. Contrary to the traditional view based on studies done in the western world, only 5% of staghorn calculi removed from patients in Sri Lanka are struvite or infection stones.

The Sri Lanka Journal of Surgery 2015; 33(2): 14-19