Artificial valves to replace the Ureterovesical Junctions: a novel approach to prevent urinary backflow

Vesicoureteral reflux is a common complication following radical cystectomy, resulting from the removal of the ureterovesical junctions (UVJ). Current bladder reconstruction methods do not address this issue, leading to potential renal complications. In this study, we designed, fabricated, and tested two passive ureteral valve designs - the Butterfly and Cap valves - to ensure unidirectional urine flow from the kidneys to the bladder when inserted into the ureters of an artificial bladder (AB). Finite Element Method simulations guided the optimization of valves. The prototypes were 3D-printed and characterized in-vitro by assessing leakage, reflux and flow rate. Results demonstrated that both valve designs effectively prevent reflux (volume loss of less than 0.3% of the AB capacity), with the Butterfly valve exhibiting slightly superior performance to prevent reflux combined with the ability to allow bladder filling. However, both valves slow down the urine flow to the AB, by 46% for the Butterfly and 57% for the Cap compared with physiological reference data. This novel approach offers a potential solution to the removal of UVJ valves towards efficient restoration of urinary functions.Clinical Relevance - This establishes the anti-reflux capability of passive ureteral valves in cases where there is a lack of UVJ.