Clinic Study Of The Composition Of Encrustation On Double J Ureteral Stent

Purpose:To determine the composition of crystalline encrustation on double J ureteral stent inserted under sterile conditions by infrared spectroscopy, in comparison with primary calculus in stone formers.Methods:322 primary calculuses and 52 double J ureteral stent encrustations between November 2010 and April 2011 were collected and analyzed with infrared spectroscopy,322 upper tract urinary calculi from stone formers were surgically removed,52 double J ureteral stent encrustations from stone formers were removed by cystoscopy(or ureteroscope). The mean dwelling time was 57 days for the stone formers.Results:The double J ureteral stent encrustations in stones formers are calcium oxalate(37, in 13 cases together with apatite and 3 cases together with uric acid), struvite(3), apatite(4,in 3 cases together with calcium oxalate), uric acid(8).It is also identified that the primary calculuses in stone formers are calcium oxalate(40, in 14 cases together with apatite and 4 cases together with uric acid), struvite(2), apatite(5, in 4 cases together with calcium oxalate), uric acid(5).Conclusions:The short duration of stenting time does not influence the presence and composition of encrustation.Calcium oxalate is the predominant type of encrustation on double J ureteral stent in stone formers.Both the composition of primary calculus in stone former and crystalline encrustation on double J ureteral stent are similar. The mean weight of double J ureteral encrustation of stone formers was 76.5mg. Infrared spectroscopy analysis of double J ureteral stent encrustations is a reliable method of predicting stone composition when the stone cannot be retrieved.