[Comparison of the composition of DJ tube encrustation and original stone and analysis of its causes].

To compare the composition of DJ tube encrustation and original stone, and to discuss the causes and prevention of encrustations. Twenty-five patients with DJ tube encrustation (1 case of INLAY OPTIMA(®) tube, Bard Medical, 16 cases of Universa(®) Firm tube, Cook Medical, 8 cases of Polaris™ Loop tube, Boston Scientific) in our institution from Januarry 2018 to April 2019 wereretrospective analyzed. Stones and encrustations were analyzed using the Fourier transform infrared spectroscopy analysis system to compare the differences in composition. 76% (19/25) patients had the exact same DJ tube encrustations composition as the original stone component; 24% (6/25) patients had DJ tube encrustation and original stone composition inconsistent (5 cases of calcium oxalate stone, 1 case of apatite carbonate.) It maybe related to the control of urinary tract infection after ureteral obstruction. The earliest DJ tube with encrustation was a pre-expansion tube before flexible-ureteroscopy, and the indwelling time was only 18 days. DJ tubes of different brands and models have the risk of formation of encrustation. Most of the encrustation has the same composition as the original stone. The prevention of DJ tube scorpion can be started from: (1) removing the DJ tube within 6 weeks or replace it regularly when necessary; (2) selecting the appropriate tube including diameter and model; (3) actively controlling urinary tract infection; (4) treating the metabolic diseases, such as hypercalcemia, hyperuricemia, et al, and providing personalized guidance for each patient.