Novel anti-reflux ureteral skirt: proof of concept in a Yorkshire-Landrace pig model.

Introduction: Stents with anti-reflux properties have been previously described in various studies but not widely adopted. We designed, constructed and tested a novel umbrella-looking anti-reflux skirt on a double J stent at the level of the ureteral orifice in a previous ex-vivo study. This study serves as a proof of concept of testing this prototype in a porcine model.

Methods: 3 Yorkshire-Landrace pigs were put under general anaesthesia. Conventional bilateral retrograde stenting with white-colored double-J stents were performed. Deployment of anti-reflux skirt was performed unilaterally. Capsaicin mixed with methylene blue and saline were instilled in the bladder. Both stents were removed and methylene blue stain were inspected to assess the level of reflux. Bilateral stenting was performed again and stents/skirt prototype were left in-situ for 1 week. The procedure was repeated on Day 7 to re-test the anti-reflux property of the prototype after ureteral dilatation.

Results: Intraluminal reflux was evident, with methylene blue stain seen on the inner surface of the stents. Extraluminal reflux was proved with blue stain seen on the outer surface of the stents, both in undilated and dilated ureters. Study also proved the anti-reflux property of the skirt as the blue stain didn't go beyond the skirt, whereas the contralateral stent was stained up to proximal ureter.

Conclusion: In this porcine in-vivo study, we elucidated that reflux occurred were both intraluminal and extraluminally. As a proof of concept, it also showed the anti-reflux property of a novel ureteral skirt.