Background: Recto-vaginal fistula is primarily one of the co-morbidities of vaginal delivery. These patients suffer from persistent malodor vaginal discharge. Various surgical techniques have been employed by surgeons in the course of time. This is the first trial of applying Human Amniotic Membrane (HAM) as a bio-prosthesis in repairing recto-vaginal fistula. Materials and Methods: In a prospective animal study, 8 mixed-breed female dogs weighing 23-27 kg with the age of 12-18 months were selected. They were randomly divided into two groups for standard recto-vaginal fistula repair and fistula repair with human amniotic membrane. The Kruskal-Wallis and Mann Whitney tests were performed to indicate statistical differences. Results: After 6 weeks, fistulas were evaluated both grossly and microscopically. In gross examination, there were no difference between the two groups and healing of fistula seemed to have been occurred in all dogs expect for one which had a persistent patent fistulous tract. Microscopic healing was scored according to epithelialization, collagenization inflammation, ulcer and necrosis of samples. Healing score was significantly higher in the HAM group than the standard group (P = 0.029). Conclusion: Our findings revealed that using HAM as a bio-prosthesis to repair recto-vaginal fistula would result in better surgical and histological outcomes comparing to simple repair.

Background: There is a growing tendency toward application of human amniotic membrane (HAM) as a biologic substitute in various tissue injuries where a significant tissue loss is a matter of concern. In gastrointestinal injuries especially duodenal ones, some potential limitations in current surgical techniques contribute to not fully acceptable healing outcomes. Thus, this study was carried out to assess repair with HAM patch for duodenal defect in comparison with simple duodenoraphy in an animal model (dog). Materials and Methods: A total of 15 male German shepherd dogs weighing 23-27 kg were randomly divided into two groups. Group A with 10 dogs, which were a candidate for duodenal repair by amniotic membrane patch and Group B consisted of 5 dogs perform simple duodenorraphy. A precise control was made to match all conditions except surgical technique. Macroscopic and microscopic features of the healed duodenal lumen in both groups were recorded. Results: Gross evaluation revealed no difference in luminal diameter in both groups. Statistical analysis of duodenal diameter between both groups after operation also showed no significant difference (P_v = 0.789). Histological assessment indicated less inflammation with better wound healing in Group A. Conclusion: It seems that repairing duodenal wall defect with HAM would result in better histological outcomes compared with what is seen in simple duodenoraphy in animal models. However, there is no significant difference regarding surgical findings.