Li Dandan, Liu Shuaibin, Feng Jiexiong, Yang Jixin
Department of Pediatric Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Hubei Clinical Center of Hirschsprung's Disease and Allied Disorders, Wuhan, China.
Front Surg. 2022 May 12;9:908390. doi: 10.3389/fsurg.2022.908390. eCollection 2022.
Anal canal duplication (ACD) is a very rare duplication of the gastrointestinal tract and is described as a secondary anal orifice along the posterior side of the normal anal canal. Early surgical removal is advisable, also in asymptomatic patients, because of the risk of inflammatory complications, such as recurrent crissum abscess, and malignant changes.
A previously healthy 2-year-old boy was evaluated in the emergency department with fever. He complained of anal pain in the absence of incentive. Physical examination and ultrasound confirmed a diagnosis of perianal abscess. He was treated with incision and drainage of the abscess and intravenous antibiotics. Two months after his discharge from the hospital, he developed fever and had intervals discharge pus and pain in the same locations. Colorectal endoscopy revealed that there was no fistula opening at the rectal wall. Intraoperative fistulography showed a fistulous tract that was connected to a subcutaneous cavity. Excision of the fistulous tract and wide drainage of the deep postanal space were performed. The patient was referred to our hospital for further evaluation 6 months later. Physical examination showed a secondary anus that had not been noticed before. MRI showed an anal fistula between 1 and 3 o'clock, and preoperative fistulography revealed a 3-cm-long tubular structure without any connection with the rectum. The diagnosis of ACD was made by intraoperative examination with a metal catheter and the postoperative pathological analysis. The duplicated anal canal was resected completely via a perianal approach without any rectal injury. Histology showed a squamous epithelium in the distal end with some smooth-muscle fibers. After a follow-up of 8 months, the patient has been doing well.
Recurrent crissum abscess should raise clinical attention to alimentary tract congenital malformations such as ACD. Prompt recognition of these unique presentations of ACD is needed, and complete excision through a perineal approach or posterior sagittal approach is recommended.
肛管重复畸形（ACD）是一种非常罕见的胃肠道重复畸形，表现为沿正常肛管后侧出现第二个肛门开口。由于存在诸如复发性肛周脓肿和恶性病变等炎症并发症风险，即便无症状患者也建议早期手术切除。
一名此前健康的2岁男孩因发热在急诊科接受评估。他无诱因出现肛门疼痛。体格检查和超声检查确诊为肛周脓肿。对其进行了脓肿切开引流及静脉使用抗生素治疗。出院两个月后，他再次发热，且在相同部位间歇性流脓和疼痛。结直肠内镜检查显示直肠壁无瘘口。术中瘘管造影显示一条瘘管与一个皮下腔隙相连。对瘘管进行了切除，并对肛门后深部间隙进行了广泛引流。6个月后患者转诊至我院作进一步评估。体格检查发现一个此前未被注意到的副肛门。磁共振成像（MRI）显示在1点至3点之间存在肛瘘，术前瘘管造影显示一个3厘米长的管状结构，与直肠无任何连接。通过术中金属导管检查及术后病理分析确诊为ACD。经肛周入路完整切除重复肛管，未造成任何直肠损伤。组织学检查显示远端为鳞状上皮，伴有一些平滑肌纤维。经过8个月的随访，患者情况良好。
复发性肛周脓肿应引起临床对诸如ACD等消化道先天性畸形的关注。需要及时识别ACD的这些独特表现，建议通过会阴入路或后矢状入路进行完整切除。
