Dissecting of the paravesical space associated with lower urinary tract dysfunction - a rat model.

To determine the association of opening the paravesical space in relation to its occurrence of de novo SUI in an animal model. Thirty five female Sprague Dawley rats were divided into 5 groups of 7 rats each: Control group, Sham groups(F, H), and Study groups(MF, MH). Groups labeled with "F" had the paravesical space opened, "H" had tissue dissection with no opening of the space, and "M" had mesh implanted inside the vaginal wall. Urodynamic studies, immunohistochemical analysis, and western blot were done at day 40. The mean weight and age of 35 rats were 302.1 ± 25.1 grams and 12.8 ± 1.2 weeks old. No significant differences were noted among the control, Sham F, Sham H, Study MF, and Study MH on the voiding pressure and voided volume. The Sham F and Study MF (opened paravesical space) groups had significantly lower values on leak point pressures (LPP) (p = 0.026; p < 0.001) and shorter voiding intervals (p = 0.032; p = 0.005) when compared to other groups. Immunohistochemical analysis showed IL-1 and TNF-α to be intensely increased for the Study MF group (p = 0.003; p = <0.001). MMP-2 and CD 31 markers were also significantly higher in the Study MH and MF group. NGF expression was significantly increased in the Study MF and Sham F groups. Thus, opening of the paravesical space causes an increased inflammatory reaction, which leads to tissue destruction and lower urinary tract dysfunction, exemplified in the study with low leak point pressure and shortened voiding intervals.