Anal canal duplication: experience at a single institution and literature review

Early Diagnosis of Anal Canal Duplication: The Importance of a Physical Examination

Anal canal duplication (ACD) is an extremely rare congenital anomaly of the intestinal tract that presents as an extra opening of the anal canal without communication with the anorectum. We present the case of a five-year-old male presenting to the pediatrician without symptoms and upon physical examination, a duplicated anal canal along the midline was discovered. The patient was admitted for surgery and the canal was removed via mucosal stripping. Postoperatively, the patient recovered well. The present study aims to expand on our knowledge of a very rare pathological entity and emphasize the importance of a complete pediatric physical examination.

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

Background

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.

Case presentation

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.

Conclusion

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.

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

Anal canal duplication is a rare gastrointestinal malformation characterized by extra anal orifices at 6 o'clock in the lithotomy position. To date, there have been only 110 reported cases. The purpose of this study is to contribute two infant cases, one of which is associated with anorectal stenosis, which has never been described.

Clinical Quiz-A Rare Case of Anal Canal Duplication in the Context of Currarino Syndrome

Currarino syndrome (CS) is a rare condition that presents with any combination of a sacral defect, a presacral mass, and an anorectal malformation. This collection, referred to as Currarino's triad, may not necessarily present as all three abnormalities in the diagnosis of the syndrome. Anal canal duplication (ACD) is an even rarer occurrence. We present a case that lies on the CS spectrum with an associated ACD and discuss a complex surgical challenge that necessitated a customized management plan, devised through a multidisciplinary approach.

Anal Canal Duplication in an Adult Female-Case Report and Pathology Guiding

Anal canal duplication (ACD) is a very rare condition, diagnosed and treated mostly in childhood. Less than 90 cases have been reported in the literature so far. We are presenting a case of a young woman who underwent surgical excision of the duplication when she was 27 years old. The patient was unaware of her condition and was referred from a gynaecological office to the surgical department with a history of perianal discomfort and mucus discharge. Local examination showed an external orifice posterior to the anal opening, on the median line, which had the macroscopic appearance of a secondary anal orifice. The opening was about 0.5 cm in diameter. Exploration of the tract revealed a length of about 4 cm. MRI described the aforementioned tract, parallel to the anal canal, with no other anomalies mentioned. Under spinal anesthesia, with the patient in jackknife position, the accessory anal canal was surgically excised. The pathology report showed the presence of smooth muscle fibers and typical anal glands in the specimen. After a five-year follow-up, the patient showed no recurrence or any other related local symptoms. Absence of perianal abscess from the patient history, along with the macroscopic aspect of the opening similar to a secondary anal orifice on the midline, should raise the suspicion of ACD. Due to the lack of bothersome symptomatology, the patient did not seek any special investigations for her condition until she was in her late twenties. ACD is a very rare condition in adults that might pass unnoticed, but a midline opening posterior to the anus should always raise the suspicion of a secondary anal canal. Surgery is the only cure for this condition with good results after a proper pre-operative workout to reveal others simultaneous malformations.

Anal canal duplication in children: a monocentric experience of 12 cases

PURPOSE

Anal canal duplication is a rare malformation characterized by a second perineal opening positioned behind the anus, which is generally observed at 6 o'clock in the lithotomy position. The purpose was to describe six new cases of anal canal duplication (in addition to our previously reported series of six patients) with the aim of providing further clinical information about this anomaly.

METHODS

We described 6 new cases of anal canal duplication in terms of symptoms, anatomical disposition, imaging results, and histopathology. Clinical details of these cases and those already reported (n = 12) were summarized and compared to existing literature.

RESULTS

A total of 12 cases were reported over 34 years. 17% of the patients were male, constituting the only subgroup to present a communication with the digestive tract. A single patient, diagnosed at 12 years, was symptomatic. Half of the patients had at least one associated malformation. All patients underwent surgery, either with a posterior sagittal or perineal approach.

CONCLUSION

Diagnosis of anal canal duplication should be suspected when a perineal opening positioned behind the anus is present, and necessitates further exploration by a comprehensive clinical examination and imaging. Surgery is always required, typically performed via a posterior sagittal approach. The postoperative course is usually uncomplicated.

The Controversy of Surgical Intervention for Anal Canal Duplication in Children

Objective:

Since the first definition of anal canal little has been discovered about the etiology of this rare condition. We present four asymptomatic cases of anal canal duplication with diverse clinical and surgical findings.

Methods:

A retrospective chart review was performed on four infants presenting with asymptomatic anal canal duplication, born between 2014 and 2016. Clinical characteristics and pathologic findings of patients either by radiological imaging or pathology were evaluated. The primary outcome measure was the complications.

Results:

All patients were followed-up with physical examination and ultrasound for a mean of 3.5±1.0 years, lastly seen at the beginning of 2018. The female to male ratio was 3:1. Duplicate anal canal length varied between 12-20mm, and two of the four patients had a presacral cystic mass confirmed as a tail gut cyst following surgery. At follow-up, none of the patients had developed symptoms related to anal canal duplication, regardless of whether they had surgical intervention.

Conclusion:

Though surgical management is the preferred treatment for anal canal duplication, it seems that patients who do not undergo surgery might remain free of symptoms, suggesting that surgical intervention may be unnecessary.

Anal duplication: is surgery indicated? A report of three cases and review of the literature

AIM OF THE STUDY

Anal canal duplications (ACDs) are extremely rare with only approximately 90 cases described in the literature. We report on three additional patients.

METHODS

Cases were analyzed to evaluate presenting symptoms, physical exam and MRI findings. A comprehensive literature review was performed to compare our patients to previously described cases. IRB approval was obtained for this study (19-0394).

MAIN RESULTS

The first female patient presented with an asymptomatic ACD at 2 years old. The second patient was a 13-year-old female with perianal drainage that was initially mistaken for a fistula-in-ano and ultimately found to have an ACD associated with a dermoid cyst. Both posterior midline duplications shared a common wall with the rectum, but did not communicate with it. The ACDs and dermoid cyst were successfully excised through a posterior sagittal approach with no postoperative complications. Histology demonstrated the presence of both squamous epithelium and transitional anal epithelium in each case. The third patient was 8 months old and had a tethered cord, hemisacrum, presacral mass, and anal duplication that was initially undiagnosed. These results corroborate patterns identified in other reports of ACDs with over 90% being female and in the posterior midline. The majority are asymptomatic, but may present with symptoms of local or even systemic infection.

CONCLUSION

An opening in the midline posterior to the anus should raise clinical suspicion for anal canal duplication. An associated presacral mass must be ruled out. Complete excision through a posterior sagittal approach is recommended upon diagnosis to avoid symptomatic presentations. The key part of the operation is the separation of the ACD from the posterior rectal wall.

Anal Canal Duplication Associated with Presacral Cyst in an Adult

Anal canal duplication (ACD) is a rare congenital malformation, usually detected early in life. We report a case of a 67-year-old female with symptomatic ACD associated with a presacral cyst. Physical examination revealed an accessory opening located in the midline, posterior to the true anus. Imaging examinations, including fistulography, endoanal ultrasonography, and magnetic resonance imaging, revealed a blind-ending fistulous tract without connecting with the rectum and a presacral cyst posterior to the rectum. Complete surgical excision of the tract with cyst was performed through a posterior sagittal approach. Histologic examination revealed squamous epithelium lining and smooth muscle bundles, thereby confirming ACD. The postoperative course was uneventful, and the patient was doing well; no recurrence was observed 4 years after surgery. ACD can present for the first time in infants, children, and adults. Imaging examinations are useful for the diagnosis and preoperative assessment of ACD. Therefore, ACD should be considered in the differential diagnosis, even in adults, when a posterior perineal orifice is encountered, particularly in female patients. Once ACD is suspected, intense imaging inspection is recommended to visualize the ACD and associated anomalies, and surgical removal is warranted to prevent inflammatory complications or malignant changes.

Fetal growth of the anal sinus and sphincters, especially in relation to anal anomalies

PURPOSE AND METHODS

The anal sinuses, small furrows above the pectinate line, sometimes form perianal abscesses in adults. We examined the pattern of fetal growth of the anal sinus and sphincters using 22 mid-term (8-18 weeks) and 6 late-stage (30-38 weeks) fetuses.

RESULTS

In mid-term fetuses, the external and internal sphincters gradually increased in thickness, depending on specimen size (from 0.2 to 1.5 mm), whereas the anteroposterior diameter of the anal canal at the epithelial junction was relatively stable (0.5-1.0 mm) irrespective of specimen size. Anal canal diameter increased less than twofold between mid-term and late-stage fetuses, from 0.5-1.0 to almost 2 mm, whereas sphincter thickness increased over tenfold, from 0.2-1.5 to almost 3.5 mm. The anal sinus often showed balloon-like enlargement when the sphincter muscle bundles were tightly packed in mid-term, but not in late-stage fetuses.

CONCLUSIONS

Large concentric mechanical stress from the sphincters in late-stage fetuses apparently prevented the anal sinus from expanding in a balloon-like manner. Conversely, to avoid anal stenosis, the growing sinuses maintained a luminal space of the anal canal in response to stress from rapidly growing sphincters. The inferiorly extending sinus usually provided temporal double canals separated by a thick column. In the presence of double lumens, anal canal duplication is likely to develop without any abnormalities of the anal epithelium and sphincters.

Anal duplication in a one-year-old girl

We report a case of a patient with anal duplication discovered incidentally at 1 year of age. Pre-operative evaluation excluded any complications or associated anomalies. She underwent surgical excision with an excellent outcome.

Anal canal duplication in an 11-year-old-child

Anal canal duplication (ACD) is the least frequent digestive duplication. Symptoms are often absent but tend to increase with age. Recognition is, however, important as almost half of the patients with ACD have concomitant malformations. We present the clinical history of an eleven-year-old girl with ACD followed by a review of symptoms, diagnosis, treatment, and prognosis based on all the reported cases in English literature.