Division of Plastic and Reconstructive Surgery, Shizuoka Cancer Center Hospital, Shizuoka, Japan.
Department of Colorectal Surgery, National Cancer Center Hospital East, Kashiwa, Japan.
Ann Surg. 2022 Apr 1;275(4):e636-e644. doi: 10.1097/SLA.0000000000004141.
Anorectal transplantation is a challenging procedure but a promising option for patients with weakened or completely absent anorectal function.
We constructed a canine model of anorectal transplantation, evaluated the long-term outcomes, and controlled rejection and infection in allotransplantation.
In the pudendal nerve function study, 6 dogs were randomly divided into 2 groups, transection and anastomosis, and were compared with a control using anorectal manometry, electromyography, and histological examination. In the anorectal transplantation model, 4 dogs were assigned to 4 groups: autotransplant, allotransplant with immunosuppression, allotransplant without immunosuppression, and normal control. Long-term function was evaluated by defecography, videography, and histological examination.
In the pudendal nerve function study, anorectal manometry indicated that the anastomosis group recovered partial function 6 months postoperatively. Microscopically, the pudendal nerve and the sphincter muscle regenerated in the anastomosis group. Anorectal transplantation was technically successful with a 3-stage operation: colostomy preparation, anorectal transplantation, and stoma closure. The dog who underwent allotransplantation and immunosuppression had 2 episodes of mild rejection, which were reversed with methylprednisolone and tacrolimus. The dog who underwent allotransplantation without immunosuppression had a severe acute rejection that resulted in graft necrosis. Successful dogs had full defecation control at the end of the study.
We describe the critical role of the pudendal nerve in anorectal function and the first long-term success with anorectal transplantation in a canine model. This report is a proof-of-concept study for anorectal transplantation as a treatment for patients with an ostomy because of anorectal dysfunction.
肛门直肠移植是一项具有挑战性的手术，但对于肛门直肠功能减弱或完全丧失的患者来说，这是一种很有前途的选择。
我们构建了犬肛门直肠移植模型，评估了长期结果，并在同种异体移植中控制了排斥和感染。
在阴部神经功能研究中，将 6 只狗随机分为 2 组，即切断和吻合，并与使用肛门直肠测压、肌电图和组织学检查的对照组进行比较。在肛门直肠移植模型中，将 4 只狗分为 4 组：自体移植、免疫抑制的同种异体移植、无免疫抑制的同种异体移植和正常对照。通过排粪造影、录像和组织学检查评估长期功能。
在阴部神经功能研究中，肛门直肠测压表明吻合组术后 6 个月部分恢复功能。显微镜下，吻合组的阴部神经和括约肌再生。肛门直肠移植通过 3 期手术成功完成：结肠造口准备、肛门直肠移植和造口关闭。接受同种异体移植和免疫抑制的狗出现 2 次轻度排斥反应，用甲基强的松龙和他克莫司逆转。未接受免疫抑制的同种异体移植狗发生严重急性排斥反应，导致移植物坏死。成功的狗在研究结束时具有完全的排便控制。
我们描述了阴部神经在肛门直肠功能中的关键作用，以及犬模型中首次成功进行肛门直肠移植。本报告是将肛门直肠移植作为治疗因肛门直肠功能障碍而进行造口术的患者的概念验证研究。
