Effect of stone composition,color,size,impaction and location on the efficacy of pneumatic ureterolithotripsy

Objective:Assessment of the relationship between stone location,composition,color,size and impaction with success rate of pneumatic ureterolithotripsy.Methods:This study was performed on 440 patients who were candidate for pneumatic uretemllthotripsy adrnitted in an academic urology department from February 2004 to June 2006.Exclusion criteria included active urinary tract infection and pregnancy.Information such as stone composition,color,impaction,size,location and surface were recorded.Success rate was defined as stone fragmentation to ＜2 mm.We used chi-square test and student t-test for statistical analysis.Results:The Success rate of pneumatic ureterolithotripsy was 83.0%.Mean stone size was 9.86±3.79 mm.The stone free rates in upper,middle and lower ureter were 66.7%,100%and 90.7%respectively(P＜0.000 1).Stone free rate was 100%and 69.35%in＜5 mm and＞5 mm stones respectively(P＜0.0001).Impaction did not correlate significandy with stone free rate(P=0.17).The Success rate was 100% in phosphate and cystine stones.There Was a significant statistical difference between success rate and stone comlxmition(P=0.026).The most common fragmented stone color Was gold(95.5%).Stone color correlated significantly with stone free rate(P＜0.0001).Conclusion:In this series ureterolithotfipsy,stone free rate had a significant correlation with stone color,size,composition and location,but it Was independent of stone impaction.