Anti-Reflux Ureteral Stent with Polymeric Flap Valve Using Three-Dimensional Printing: An In Vitro Study

Abstract

The anti-reflux ureteral stent was successfully designed and fabricated using a 3D printer. In vitro studies showed that the stent effectively prevented backward flow while minimizing reduction in forward flow.

Evaluation of a Polymeric Flap Valve-Attached Ureteral Stent for Preventing Vesicoureteral Reflux in Elevated Intravesical Pressure Conditions: A Pilot Study Using a Porcine Model

“…19 In an empty bladder state, the anterograde pressure applied from the renal pelvis is higher than the retrograde pressure applied from the bladder. This pressure difference causes the flexible flap valve to open and enables urine to flow in an anterograde direction from the renal pelvis to the empty bladder.…”

“…The specific dimensions and detailed fabrication method of the flap valve were described in our prior published work. 19 In vivo study: flap valve evaluation in a porcine model A female Yorkshire pig (49 kg) was prepared under general anesthesia for the study. Before insertion of the ureteral stents, intravenous pyelography (IVP) and simulated voiding cystourethrography (VCUG) were performed to check for the urinary tract anomalies.…”

“…The details of the experimental setup and procedure were identical as those in our prior published in vitro study. 19 …”

“…[15][16][17][18] Our group has also been attempting to develop antireflux ureteral stents for the past few years. In our prior work published in 2015, 19 a flexible polymeric flap valve that can be attached at the vesical edge of a conventional ureteral stent was introduced to prevent VUR. The flap valve was fabricated efficiently and easily using a three-dimensional (3D) printer.…”

“…As an extension of the prior study, 19 in the present study, we conducted a pilot in vivo test using a porcine model to evaluate the VUR prevention efficacy of a flap valve-attached ureteral stent. The VUR findings between the two ureters, with a flap valve-attached ureteral stent inserted into one ureter and a conventional ureteral stent inserted into the other, were compared under elevated intravesical pressure conditions in the porcine model.…”