Exploratory safety study of an umbilical cord derived urethral sling in bilateral pudendal nerves injury-induced urinary incontinence in female rats.

Abstract

Mid-urethral slings are the standard treatment for women with refractory stress urinary incontinence (SUI) but are at riskof infection or erosion due to host-prothesis interaction. In this proof-of-concept study, we aimed at evaluating umbilical vessel sling (UVS) in incontinent female rats. UVS wasextracted from human umbilical cord lining and was placed on female rats who underwent bilateral pelvic nerve injury (PNI) to reproduce SUI (Group 3, N = 10). Two control groups were also studied: rats with no PNI (Group 1, N = 4) and rats with PNI but no UVS (Group 2, N = 10). Micturition calendar was frequently recorded using a metabolic cage, and leak point pressure (LPP) test was performed on Day 28. After the LPP test, rats were euthanized, and bladder/urethra were collected for histopathological analysis. Overall, 24 rats were included,of whom 10 had both PNI and UVS placement. Compared with Group 2, Group 3 had increased maximal LPP but the difference did not reach significance (respectively 21.8 ± 2.1 mmHg vs. 28.4 ± 4.1 mmHg, p = 0.2). Micturition frequencies were similar between the groups. Total voided volume was higher in Group 3 at the end of the study compared with Group 2 (12.5 ± 1.1 ml vs. 9.4 ± 0.6 ml,respectively, p < 0.05). Histopathological findings evidenced a good local tolerance and a moderate to high tissue integration of the UVS. Biological sling derived from human umbilical vessel could be safely placed with a slight improvement of LPP in a population of rats who had bilateral PNI without major modification of micturition calendar. UVS could be a promising biomaterial in the management of SUI in women. Clinical studies are needed.