Anti-adhesion agent to prevent of post-operative adhesion and fibrosis after vasectomy: a study using a rat model.

Background: Post-vasectomy pain syndrome (PVPS) is difficult to treat. Direct damage to the vas deferens, inflammation, compression of nerves through fibrotic adhesions, and congestion of the epididymis are known to cause PVPS. The purpose of this study was to evaluate whether the application of anti-adhesion agents after vasectomy can reduce the degree of adhesion and fibrosis in a rat model. Methods: In the study, 11 Sprague-Dawley rats (22 vas deferens) from each group were evaluated. In the experimental group, surgery was terminated after applying the anti-adhesion agent; this was not applied in the control group. After 14 days of vasectomy, the scrotum was dissected to evaluate the degree of gross adhesion at the vasectomy site. Histological examination of the surrounding tissues, including the vas deferens and the spermatic cord, was also performed. Results: Adhesions were not observed in 72.73% (16/22) rats from the experimental group, in which the anti-adhesion agent was applied; in contrast, the incidence of adhesions in the control group was 100%. There was a statistically significant relationship between the distribution of grades for adhesion and anti-adhesion agent (chi-square, P<0.001). On classification of fibrosis and inflammation, application of the anti-adhesion agent was significantly associated with lower grade inflammation and fibrosis compared to that of the control group (chi-square, P=0.001). The rate of intact muscle structure was 90.91% (20/22) in the experimental group, and 36.36% (8/22) in the control group, and the application of the anti-adhesion agent demonstrated significant association with preservation of intact muscle structure (chi-square, P<0.001). Conclusions: The application of an anti-adhesion agent after vasectomy prevented the development of adhesion, fibrosis, and inflammation reaction and further reduced structural destruction.