Torrecilla, CarlosFernández-Concha, JaimeCansino, José RMainez, Juan AAmón, José HCostas, SimbadAngerri, OriolEmiliani, EstebanArrabal Martín, Miguel AArrabal Polo, Miguel AGarcía, AnaReina, Manuel CSánchez, Juan FBudía, AlbertoPérez-Fentes, DanielGrases, FélixCosta-Bauzá, AntoniaCuñé, Jordi2023-02-092023-02-092020-06-05http://hdl.handle.net/10668/15690Encrustation of ureteral double J stents is a common complication that may affect its removal. The aim of the proposed study is to evaluate the efficacy and safety of a new oral composition to prevent double J stent encrustation in indwelling times up to 8 weeks. A double-blinded, multicenter, placebo-controlled trial was conducted with 105 patients with indwelling double J stents enrolled across 9 public hospitals in Spain. The patients were randomly assigned (1:1) into intervention (53 patients) or placebo (52 patients) groups for 3 to 8 weeks and both groups self-monitored daily their morning urine pH levels. The primary outcome of analysis was the degree of stent ends encrustation, defined by a 4-point score (0 - none; 3 - global encrustation) using macroscopic and electron microscopy analysis of crystals, after 3 to 8-w indwelling period. Score was exponentially transformed according to calcium levels. Secondary endpoints included urine pH decrease, stent removal, and incidence of adverse events. The intervention group benefits from a lower global encrustation rate of stent ends than placebo group (1% vs 8.2%; p  Our data suggest that the use of this new oral composition is beneficial in the context of ureteral double J indwelling by decreasing mean, as well as global encrustation. This trial was registered at www.clinicaltrials.gov under the name "Combined Use of a Medical Device and a Dietary Complement in Patient Urinary pH Control in Patients With an Implanted Double J Stent" with date 2nd November 2017, code NCT03343275, and URL.enAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/Double J stentEncrustationL-methionineNutraceuticalPhytinpHAdministration, OralAdultCalcinosisCrystallizationDouble-Blind MethodFemaleHumansHydrogen-Ion ConcentrationMaleMethionineMiddle AgedPhytic AcidPostoperative ComplicationsProspective StudiesProsthesis FailureStentsUreterUrineresearch article32503502open access10.1186/s12894-020-00633-21471-2490PMC7275439https://bmcurol.biomedcentral.com/counter/pdf/10.1186/s12894-020-00633-2https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7275439/pdf