Anal Canal Duplication Mimicking Recurrent Abscess: A Case Report and Review of the Literature

Abstract

BackgroundAnal 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.Case presentationA 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.ConclusionRecurrent 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.

Anal Canal Duplication in a 25-Year-Old Female Patient

“…The most useful diagnostic studies are fistulography, magnetic resonance imaging, and anoscopy [4,7]; however, a surgical specimen with a histopathology report is always necessary [7,8]. In our case, the histopathology findings showed stratified epithelium and the presence of smooth muscle fibers, and inflammation associated with transitional epithelium was observed, as reported in other cases in the literature [3].…”

“…ACD presents and is usually diagnosed early in life [4,5]. Thirty-six percent of cases may be associated with other malformations [4] such as myelomeningocele, midline defects [6,7], or most commonly, urinary malformations in up to 45% of cases [8]. It is even part of some rare syndromes such as Currarino syndrome, which include a characteristic triad associating anal stenosis, sacrococcygeal malformation, and presacral mass [1].…”

Case Report: Anal canal duplication associated with anorectal stenosis—A rare presentation

“…The clinical features of ACD, the anatomic relationship with the anal sphincter, and its associated malformations are important determinants of the surgical approach ( 21 ). For cases associated with ARMs and presacral mass, the posterior sagittal approach is recommended ( 22 ). In our case, the ACD was located in the rectum and no presacral malformations were associated.…”