Fabrication And In Vitro Feasibility Research Of Newly Designed Ureteral Stent With Antireflux Device

Purpose: The placement of a double J stent is a widespread procedure performed to relieve ureter blockages for benign or malignant reasons. However, the double J stent may lead to a number of complications. Bypassing the ureterovesical junction, the traditional stent can cause bladder pressure reflection to the renal pelvis and vesicoureteral reflux(VUR), which in turn will render one predisposed to urinary tract infections(UTIs). Moreover, VUR and UTIs may result in scarring and renalfailure. To solve this problem, we developed two advanced double J stents with anti-reflux device and evaluated the effectiveness of these new double J stents by in vitro studies.Methods: We designed and manufactured two newly designed double J stents with anti-reflux device(Model Q-1、Model Q-2). 60 pieces of standard double J stents were randomly divided into three groups, group A, group B and group C, each group20 pieces. A were converted into Model Q-1 while B were converted into Model Q-2.In vitro testing was conducted to evaluate the drainage and antireflux characteristics of Model Q-1(group A)、Model Q-2(group B) and standard double J stent(group C).In an in vitro experimental model, we compared the resistance of ureteral placement among the three groups and the force of stent insertion was measured. Statistic and compare the data of three groups.Results: Two newly designed double J stents with anti-reflux device(Model Q-1、Model Q-2)were manufactured. In vitro testing, there were significant difference among the three group in anti-reflux properties(P<0.01), 20 cases in both group A and group B had positive results of anti-reflux(100%, 20/20), while 0 case in group C(0%, 0/20). In terms of drainage properties at three different pressure(30cm H2 O,20cm H2 O and 12 cm H2O), there was notable difference among three groups(P<0.01).Among them, group C was the best, group A the worst, and group B between them.For the force of stent insertion, group A was the highest, and group C was the lowest(P<0.05).Conclusion:The two newly designed double J stents with anti-reflux device(Model Q-1、Model Q-2)had favorable drainage and perfect anti-reflux properties and were easily placed over a guidwire. The novel ureteral stent got a lot of flexibility and had a bright prospect.