Relationship between pain and nerve fibers distribution in multiple endometriosis lesions

Abstract

To investigate the relationship between the distribution of nerve fibers in multiple endometriosis lesions and pelvic pain. From Sept. 2007 to Sept. 2008, 120 endometriosis patients treated in Peking Union Hospital were enrolled in this study, which including 19 cases with stage I, 29 cases with stage II, 44 cases with stage III and 28 cases with stage IV. The pain symptom was evaluated by visual analogue scales (VAS) score and nerve fibers in multiple endometriosis lesions were detected by immunohistochemical staining. The number of nerve fibers in multiple endometriosis lesions were (29.74+/-17.33)/mm2 in uterosacral ligament, (24.53+/-13.34)/mm2 in vaginal septum, (17.09+/-10.09)/mm2 in uterus rectum crux, (6.77+/-4.21)/mm2 in peritoneal endometriosis lesions, (0.07+/-0.25)/mm2 in endometriosis ovarian cyst wall. The number of nerve fibers in uterosacral ligament was mostly correlated with the degree of pain (r=0.56). The nerve fibers of uterus rectum crux and vaginal septum were correlated with defecation pain (r=0.58 and 0.41) and dyspareunia (r=0.82 and 0.67), which were significantly higher than those in endometriosis leision in peritoneum and ovary. There was no significant different number of nerve fibers among different stage disease (P>0.05). There was significantly different distribution of nerve fibers in multiple endometriosis lesions, which was correlated with dysmenorrhea, anus pain, dyspareunia and chronic pelvic pain, not with clinical staging.