Histology with immunohistochemistry of the fistula region in female anorectal malformation: Can it be used for neo-anus reconstruction?

Rethinking Fistula Preservation in Anorectal Malformation Surgery: A Histopathological Perspective

OBJECTIVE

 This study aims to assess the histopathological characteristics of the fistulous tissue in males with anorectal malformation (ARM) to determine its suitability for use in constructing a neoanus.

METHODS

 This prospective observational study included male ARM patients with recto-urethral fistula. All other types were excluded. The tissue specimens comprised 0.5 to 2.0 cm of the most distal part of the rectal pouch and the fistulous tissue. Hematoxylin and eosin-stained sections were prepared. Histological features, viz. internal sphincter, anal grand and crypts, ganglion cells, presence of subepithelial fibrosis, thickened nerve trunks, and metaplasia, were evaluated.

RESULTS

 Of 65 patients of ARM admitted, 24 met the inclusion criteria. Gross and microscopic internal sphincter was not found in any sample. The anal mucosa was visualized in all samples; however, crypts were irregular and distorted architecture was seen in 4 (16.67%) samples. Urothelial metaplasia was identified in 10 (41.67%) samples. Adequate ganglion cells were seen only in 6 (25%) samples. Significant submucosal fibrosis was seen in all samples. Thickened nerve trunks were identified in 4 (16.67%) samples.

CONCLUSIONS

 All normal anal histological features could not be found together in the fistula tissue. With the absence of normal features, such as internal anal sphincter muscles, and the presence of abnormal histopathological features, such as subepithelial fibrosis, thickened nerve trunks, and metaplasia, there are high chances of abnormal bowel function like constipation if the fistulous tissue is used for neoanus construction. It may have an impact on the quality of life of patients.

Rectal biopsy: is it really necessary in anorectal malformations?

AIM OF THE STUDY

The coexistence of Hirschsprung's disease (HD) with anorectal malformation (ARM) is rare but many surgeons still ask pathologists to look for ganglia in the terminal rectum or fistula. In this study, we aimed to highlight the rarity of this association and question the necessity of histological evaluation.

METHODS

After obtaining board review approval, rectal specimens of ARM patients who underwent corrective surgery in the last 8 years were re-analyzed by two blinded pathologists for the presence and structure of ganglia. Clinical and radiological data of patients retrieved from center records and correlated with histopathologic findings.

MAIN RESULTS

67 patients with ARM were identified, distal rectal specimen was obtained in 47. The median age at the time of surgery was 11 months (2 days-59 months). A normal pattern of ganglia was present in 51.1% (24/47), 29.7% (14/47) had aganglionosis and 19.1% (9/47) were inconclusive due to insufficient material. None of the aganglionic specimens showed other histological findings of HD. Patients were followed up regularly in the outpatient colorectal clinic for a median of 87 months (42-117 m). Only 6 experienced severe constipation (3 ganglionic, 2 no biopsy, 1 aganglionic), all of whom responded to a bowel management program, and none developed other manifestations of HD (abdominal distension, failure to thrive or enterocolitis) or required additional surgery.

CONCLUSIONS

Our results strongly suggest that the association of ARM and HD is extremely rare and the practice of searching for ganglia in the distal rectum or fistula of ARM patients should be discouraged to avoid potential misdiagnosis and overtreatment.

Clinical Differentiation between a Normal Anus, Anterior Anus, Congenital Anal Stenosis, and Perineal Fistula: Definitions and Consequences—The ARM-Net Consortium Consensus

In the past, an anteriorly located anus was often misdiagnosed and treated as an anorectal malformation (ARM) with a perineal fistula (PF). The paper aims to define the criteria for a normal anus, an anterior anus (AA) as an anatomic variant, and milder types of ARM such as congenital anal stenosis (CAS) and PF. An extensive literature search was performed by a working group of the ARM-Net Consortium concerning the subject “Normal Anus, AA, and mild ARM”. A consensus on definitions, clinical characteristics, diagnostic management, and treatment modalities was established, and a diagnostic algorithm was proposed. The algorithm enables pediatricians, midwives, gynecologists, and surgeons to make a timely correct diagnosis of any abnormally looking anus and initiate further management if needed. Thus, the routine physical inspection of a newborn should include the inspection of the anus and define its position, relation to the external sphincter, and caliber. A correct diagnosis and use of the presented terminology will avoid misclassifications and allow the initiation of correct management. This will provide a reliable comparison of different therapeutic management and outcomes of these patient cohorts in the future.

Evaluation and management of "low" anorectal malformation in male children: an observational study

PURPOSE

ARM with perineal fistula has been traditionally defined as low ARM (LARM). This study was conducted to evaluate LARM in male patients with an emphasis on the role of various factors on the outcome and follow-up of them.

MATERIALS AND METHODS

It was a retrospective cohort study. The clinical presentation, associated anomalies, and complications were assessed. The operative procedures included cutback anoplasty and others. The patients were followed in the outpatient department. The complications were assessed and managed accordingly.

RESULTS

During the study period of 8 years, 301 patients were admitted. The complaints included absent or abnormal anal opening, abdominal distension, constipation, and peritonitis. Most of the children (n = 214) presented in the neonatal period. The most common clinical presentation was the perineal fistula. The most common associated anomaly was urologic. Fourteen patients were referred from other centers after complications. The most common problem in follow-up was constipation.

CONCLUSION

LARM in male patients may have a diverse presentation. The associated anomalies need proper assessment. Awareness may avoid delayed presentation and unwanted complications. When managed by an expert, the condition can be effectively managed. Regular follow-up is important.

Evaluation and management of rectovaginal fistula in anorectal malformation: an observational study

PURPOSE

The rectovaginal fistula (RVF) is a type of female ARM in which the rectum terminates in the vagina. Due to its rarity, there are limited reports on its presentation, management, and follow-up. This paper deals with the clinical presentation, management, and outcome of RVF.

METHODS

It was a retrospective cohort study of 10 years. The patients were evaluated for age, clinical presentation, associated anomalies, any prior surgical interventions performed elsewhere, and complications. After workup, the patients underwent three stages of surgery.

RESULTS

Fifty-six patients of RVF were managed. The median age was 13.48 months. The associated anomalies were present in 37 (66%) patients. Posterosagittal and anterosagittal anorectoplasty (PSARP and ASARP) were performed in 29 and 6 patients, respectively. Abdominoperineal pull-through (APPT) was performed in 16 patients of congenital pouch colon. The complications of the first stage included stomal stenosis (4) and stomal prolapse (3). Constipation was present in 39 patients 2 years after the third surgery.

CONCLUSIONS

RVF is a distinct entity, which needs careful clinical examination. With proper planning for diagnosis and treatment, it can be managed at specialized centers. Care may be needed for the associated anomalies. The follow-up is an integral part of its management.

Laparoscopic-assisted anorectoplasty for intermediate type rectovestibular fistula: a preliminary report

PURPOSE

Laparoscopic-assisted anorectoplasty (LAARP) is considered to benefit the male patients with anorectal malformation (ARM). This study evaluates LAARP management for intermediate type rectovestibular fistula (IRVF) in the female patient with ARM.

METHODS

Twelve patients with IRVF (aged 3-5 months) underwent LAARP from 2017 to 2019 in our institute. LAARP was performed for mobilization of the rectum, visualization and enlargement of the center of the sphincter muscle complex (SMC) from pelvic and perineal aspects, intra-fistula mucosectomy and rectal pull-through in the SMC with the fourchette and the perineal body unattached.

RESULTS

LARRP was performed in all patients without conversion to open procedure. No patient suffered from wound infection, vaginal injury, recurrent fistula and anal stenosis. The parents were satisfied with the appearance of the wound. Rectal prolapse developed in one patient and needed surgical correction. The patients were followed up for a mean of 19.7 months (ranged from 12 to 35 months).

CONCLUSION

Our preliminary experience shows that LAARP offers an alternative method of correction for the IRVF with good visualization of the SMC and may diminish the risks of wound dehiscence and vaginal injury.

Histopathologic and immunohistochemical findings in congenital anorectal malformations

It remains controversial whether the distal rectal pouch should be either resected or used for reconstruction in anorectoplasty for the treatment of anorectal malformations (ARMs). Hence the aim of this study was to investigate whether ARMs were associated with a global neuromuscular maldevelopment of the terminal rectum specimens.There were 36 cases of ARMs (25 recto-bulbar fistula and 11 recto-prostatic fistula) and 10 healthy controls. The hematoxylin and eosin and Masson trichrome stain were used to conduct the histologic examination. The immunohistochemistry (IHC) and Western blot were conducted to analyze the neuron-specific enolase (NSE), S-100 protein, interstitial cells of Cajal marker (C-kit) within the rectal specimens in control group and ARM group.The most frequently observed histologic findings in mucosa were inflammation, congestion, eroded, and hemorrhage in the ARM cases. Submucosal inflammation and congestion were the most common submucosal findings in the ARM cases. Disrupted muscularis propria was observed in 60% of ARM cases. Mature ganglionic cells were reduced and muscularis propria showed reduced and patchy positivity for NSE, S-100, and C-kit protein in ARM group compared to that in control group according to IHC. Western blotting showed the expression levels of NSE, S-100, and C-kit were lower in the ARM group than that in the control group (P < .01).Histopathologic and IHC findings suggest that the distal rectal pouch has distinct defects in the neuromusculature. So it suggested that ARMs are abnormally developed tissue and need to be resected for better functional outcomes of the remaining gut.