Effect of a Silicone Hydrocoated Double Loop Ureteral Stent on Symptoms and Quality of Life in Patients Undergoing F-URS for Kidney Stone; a Comparative Randomized Multicenter Clinical Study.

The double loop stents are used for both prevention and treatment of ureteral obstruction: They permit the interim internal bypass drainage of urine when obstruction in the ureter especially in cases of lithiasis or after surgical intervention on the upper urinary tract.

There are many indications for double loop stent placement and population chosen for this study are adult patients with intra-renal calcium calculi of 7-20 mm in diameter for whom the treatment indication is a flexible ureterorenoscopy.

The aims of the use of a double loop stent are to

prevent complications (pain, infection) associated with the ureteral obstruction by any residual stone fragments, blood clot or local oedema generated by the intervention.

preserve the renal function.

facilitate healing process while limiting the risk of stenosis and probably reduce the rate of readmission after patients' discharge.

Double loop Stent-related symptoms have a high prevalence and may affect over 80% of patients.

Assessment tools are important to determine the symptoms intensity and allow for comparisons at different times. The Urinary Stent Symptom Questionnaire (USSQ) is the most adapted tool designed for this purpose.

An ideal ureteral stent is expected to drain well, to be easy to insert and to be comfortable for the patients. The investigators designed a hydro-coated Silicone JJ stent with additional properties for improving patient's comfort.

The investigators decided to perform a randomized clinical investigation to evaluate the Coloplast Hydrocoated Silicone JJ in comparison to the Boston Percuflex Plus JJ stent on patients' comfort.