Investigating the effect of human amniotic membrane gel to minimize adhesions in endometriosis: findings from an experimental study using a rat model

OBJECTIVE: Postoperative adhesions and inflammation remain major challenges following endometriosis surgery. Human amniotic membrane gel (HAG) has emerged as a potential therapeutic strategy with both anti-adhesive and anti-inflammatory properties. This study aimed to evaluate the efficacy of intraperitoneal HAG in reducing adhesion severity, lesion persistence, and inflammatory cytokine levels in an experimental rat model of endometriosis. METHODS: Forty-four adult female Wistar rats underwent surgical induction of endometriosis through autotransplantation of uterine horn tissue. After 3 weeks, the animals were randomized into two groups (n=22 each): one receiving intraperitoneal HAG and the other receiving normal saline during a second laparotomy. Adhesion severity was evaluated using the Hoffmann and Lauder scoring systems. Two weeks after the intervention, endometriotic lesion size was measured. Serum levels of interleukin (IL)-6 and IL-1β were assessed at three time points. Histopathological examination was conducted to evaluate the presence of endometriotic tissue, fibrosis, abscess formation, and adipose tissue remodeling. RESULTS: Rats treated with HAG showed a significant reduction in lesion size (6.8 mm² vs. 81 mm², p<0.001) and significantly lower adhesion scores (p<0.001). Persistent endometriosis was observed in only 36% of animals in the HAG group compared with 95.5% in the control group (p<0.001). Histological analysis demonstrated fewer fibrotic and purulent reactions and a shift toward adipose tissue remodeling in the HAG-treated animals. Serum IL-6 and IL-1β levels decreased significantly in the HAG group, whereas both cytokines increased in the control group (p<0.001 for both). CONCLUSION: HAG significantly improved macroscopic, histological, and biochemical outcomes in this experimental model. These findings suggest that HAG may serve as a biologically active adjunct for reducing postoperative adhesion formation and inflammation in endometriosis.