Histopathologic and immunohistochemical findings in congenital anorectal malformations

Perioperative Histologically Controlled Fistula Resection in Patients with Imperforate Anus and Perineal Fistula

INTRODUCTION

 Postoperative constipation (PC) in patients with imperforate anus and perineal fistula (PF) has been reported in up to 60%. Histological studies of PF revealed innervation anomalies which seem to be one of the reasons for PC. Perioperative histologically controlled fistula resection (PHCFR) allows appropriate resection of PF and pull-down normoganglionic rectum at the time of posterior sagittal anorectoplasty (PSARP).

MATERIALS AND METHODS

 A total of 665 patients with anorectal malformations underwent surgery between 1991 and 2021. Of these, 364 presented PF; 92 out of them (41 F) were studied. Patients with sacral and spinal cord anomalies, neurological disorders, and cut-back anoplasty were excluded. PSARP was done on all patients. Hematoxylin-eosin staining and NADH Tetrazolium-reductase histochemical method were used. Four and more ganglion cells in the myenteric plexus represented a sufficient length of the resection. The continence was scored according to the modified Krickenbeck scoring system. Final scores ranged from 1 to 7 points. Values are given as median.

RESULTS

 A total of 65 (70.7%) patients presented an aganglionic segment in PF, and 27 patients presented hypoganglionosis. The median length of the resected fistula was 25 mm (interquartile range [IQR]: 20-30). The median total continence score was 7 (IQR: 6-7). Post-op constipation was observed in 6/92 (6.5%) patients.

CONCLUSION

 PHCFR diminished PC to 6.5% of patients.

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.

Laparoscopic-assisted distal colon excision and proximal colon pull-through anorectoplasty for anorectal malformation

Purpose

During the second stage surgery for anorectal malformations (ARM), patients whose distal intestine of the colostomy is particularly short underwent laparoscopic-assisted distal colon excision and proximal colon pull-through anorectoplasty (PCPARP). This study aimed to discuss the outcomes of PCPARP after colostomy in patients with ARM.

Methods

This is a single-center propensity score-matched (PSM) study which was retrospectively initiated patients with intermediate- or high-type ARM who underwent laparoscopic surgery from June 2007 to December 2018. These patients were divided into PCPARP group and conventional laparoscopic-assisted anorectoplasty (LAARP) group according to specific surgical methods. The general data, surgical data, postoperative complications, and functional results were evaluated.

Results

In total, 216 patients were included in this study: 190 (88.0%) undergoing LAARP approach and 26 (12.0%) undergoing PCPARP approach. After PSM, two well-balanced groups of 26 patients were analyzed and showed the postoperative complications (P = 0.126) and bowel function (P = 0.809) were similiar between the two groups.

Conclusions

The curative effect of PCPARP after colostomy is similar to that of classic LAARP surgery, which can be used for ARM patients with a very short and abnormal distal intestine of the stoma.

Significance of searching for ganglia in the terminal rectum/fistula of complex anorectal malformations: Related to defecation function

Background

The need to search for ganglia in the terminal rectum/fistula of complex anorectal malformations (ARMs) remains controversial. This study aims to evaluate the relationship between ganglia absence in the terminal rectum/fistula and defecation function after anoplasty.

Methods

A retrospective review of patients who received anoplasty for treating male imperforate anus with rectobulbar (RB)/rectoprostatic (RP) fistulas at a tertiary pediatric hospital was conducted with registered demographic data, imaging study results, and information on the terminal rectum/fistula specimen (excision extension and pathological findings). According to the pathological findings, patients were divided into Groups 1 (ganglia absence) and 2 (ganglia presence). Furthermore, the postoperative defecation function was evaluated using various rating scale questionnaires. Statistical analysis was performed using SPSS 22.0.

Results

Of the 62 patients, 18 (29.0%) showed ganglia absence in the terminal rectum/fistula. By analyzing the imaging data, spinal anomalies and spinal cord anomalies were found in 30.6% (19/62) and 56.5% (35/62) of patients, respectively. Baseline information was comparable between Groups 1 and 2 (P > 0.05). For defecation function, there were no significant differences in Kelly scores between the two groups (4.0 ± 0.8 vs. 4.4 ± 1.1, P = 0.177), while Krickenbeck (3.7 ± 1.8 vs. 5.2 ± 1.4) and Rintala (13.7 ± 3.6 vs. 16.0 ± 2.7) scores in Group 1 were significantly lower than those in Group 2 (both P < 0.05). The overall incidence of constipation was 50% (31/62), being higher for Group 1 than Group 2 (77.5% vs. 38.6%, P = 0.002). The area under the curve of ganglia absence for predicting constipation was 0.696, with 77.8% sensitivity and 61.4% specificity.

Conclusion

Ganglia absence in the terminal rectum/fistula of male imperforate anus with RB/RP fistulas is associated with constipation after anoplasty, but it has limited predictive value for postoperative constipation. It is necessary to search for ganglia in the terminal rectum/fistula, both intraoperatively and postoperatively.

Laparoscopic-Assisted Anorectoplasty for Rectovestibular Fistula: A Comparison Study with Anterior Sagittal Anorectoplasty

BACKGROUND

 Posterior or anterior sagittal anorectoplasty (ASARP) is the mainstream for correcting rectovestibular fistula (RVF). However, the intermediate RVF has the potential risk of wound complications when applying ASARP due to its high rectal pouch, long fistula tract, and difficulty separating the rectum and vagina. We developed laparoscopic-assisted anorectoplasty (LAARP) for surgical correction of RVF, which has acceptable preliminary outcomes. The purpose of this study is to evaluate the safety and efficacy of LAARP in comparison with ASARP for patients with RVF.

MATERIALS AND METHODS

 Twenty-five patients with RVF who underwent LAARP between October 2017 and December 2020 were retrospectively reviewed. The outcomes were compared with 43 patients who underwent ASARP between April 2015 and August 2018. The age, weight at operation, sacral ratio, operative time, and postoperative hospital stay were evaluated. The results were assessed for complications, perineum appearance, and bowel function.

RESULTS

 The two groups were comparable in terms of demographics. The median operative time of the LAARP group was significantly longer than that of the ASARP group (113 vs. 95 minutes; p = 0.015). The mean length of the resected rectum in the LAARP group was also longer than that in the ASARP group (6.75 ± 5.07 vs. 3.31 ± 3.06 cm; p = 0.001). Compared with the LAARP group, complications in the ASARP group were more frequent (4.0 vs. 27.9%, p = 0.036). No intraoperative or postoperative wound-related complications occurred in the LAARP group. However, in the ASARP group, one patient had an intraoperative vaginal injury and four had postoperative anastomosis-related complications. The incidence of redo operation in the ASARP group was significantly higher than that in the LAARP group (p = 0.000). Cosmetic satisfaction was higher in the LAARP group (96.0 vs. 76.7%; p < 0.05). In terms of voluntary bowel movement, soiling, and constipation, the LAARP group had similar results compare with the ASARP group.

CONCLUSION

 The LAARP technique has shown several unique strengths in treating intermediate type RVF, including lower risks of complications, and minimal muscular injury, with a comparable bowel function.

Megarectum: systematic histopathological evaluation of 35 patients and new common pathways in chronic rectal dilatation

AIMS

Megarectum is well described in the surgical literature but few contemporary pathological studies have been undertaken. There is uncertainty whether 'idiopathic' megarectum is a primary neuromuscular disorder or whether chronic dilatation leads to previously reported and unreported pathological changes. We sought to answer this question.

METHODS

Systematic histopathological evaluation (in accord with international guidance) of 35 consecutive patients undergoing rectal excision surgery for megarectum (primary: n=24) or megarectum following surgical correction of anorectal malformation (secondary: n=11) in a UK university hospital with adult/paediatric surgical and gastrointestinal neuropathology expertise.

RESULTS

We confirmed some previously reported observations, notably hypertrophy of the muscularis propria (27 of 35, 77.1% of patients) and extensive fibrosis (30 of 35, 85.7% of patients). We also observed unique and previously unreported features including elastosis (19 of 33, 57.6%) and the presence of polyglucosan bodies (15 of 32, 46.9% of patients). In contrast to previous literature, few patients had any strong evidence of specific forms of visceral neuropathy (5 of 35, including 3 plexus duplications) or myopathy (6 of 35, including 3 muscle duplications). All major pathological findings were common to both primary and secondary forms of the disease, implying that these may be a response to chronic rectal distension rather than of primary aetiology.

CONCLUSIONS

In the largest case series reported to date, we challenge the current perception of idiopathic megarectum as a primary neuromuscular disease and propose a cellular pathway model for the features present. The severe morphological changes account for some of the irreversibility of the condition and reinforce the need to prevent ongoing rectal distension when first identified.

[Morphological criteria for surgical treatment of anorectal malformations in children]

OBJECTIVE

To improve treatment outcomes in patients with anorectal malformations via research of morphological criteria and differentiated approach to surgical correction.

MATERIAL AND METHODS

There were 37 children with various types of anorectal malformations for the period 2000-2019. We analyzed morphological features of atretic rectum wall, fistula, anastomosis with adjacent organs and skin of the perineum.

RESULTS

Morphological research of anorectal malformations made it possible to differentiate treatment strategy and explain the causes of unsatisfactory results after perineal and abdominal-perineal proctoplasty. Incidence and severity of complications, as well as early disability were reduced that significantly improved postoperative quality of life.

CONCLUSION

According to the morphological criteria, deeper mobilization of atretic rectum within at least 2.5-3 cm of the rectal «cone» with intact muscular wall is necessary. This approach was valuable to ensure adequate closure function of the rectum, prevent anal incontinence and restore normal appearance of the perineum. These achievements contributed to decrease in the incidence of admissions, redo surgeries and improvement of social adaptation in children.

Epithelial and ganglionic distribution at the distal rectal end in anorectal malformations: could it play a role in anastomotic adaptation?

PURPOSE

In anorectal malformations (ARMs), the epithelium of the distal rectal end is not well described. We histomorphologically evaluated epithelial and ganglionic distribution in the distal rectal end of ARMs resected during anorectoplasty to assess similarities and differences with normal anal canal structure.

METHODS

In this single-center retrospective study, specimens from 60 ARM patients (27 males, 33 females) treated between 2008 and 2019 were evaluated.

RESULTS

Epithelium type and alignment sequence as well as ganglionic distribution were similar in the distal rectal end and in a normal anal canal. Stratified columnar epithelium (anal transitional zone, ATZ) was seen in 49/60 (81.7%) cases and in all ARM types, including the no-fistula type. Anal crypts were identified in the stratified columnar epithelium (ATZ) of 46/49 (93.9%) patients. Regarding distal rectal end-resecting anorectoplasty, in 90% of patients, resection was performed distal to the Herrmann line. Ganglion cell distribution was exclusively proximal to the Herrmann line.

CONCLUSION

Epithelial and ganglionic distribution was similar in the distal rectal end of ARMs and in a normal anal canal. The ATZ is the epithelial boundary between the rectum and skin in a normal anal canal. ATZ preservation could reproduce anal canal structure in ARM reconstruction.

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.

Laparoscopic-Assisted Anorectal Pull-Through for Currarino Syndrome

Objective: Currarino syndrome (CS) is characterized by the triad of sacral anomalies, presacral tumor, and anorectal malformation (ARM). This study evaluates the feasibility and outcomes of laparoscopic-assisted anorectal pull-through (LAARP) for CS. Materials and Methods: Children admitted for primary or redo repair of CS through LAARP between 2016 and 2019 were reviewed. The indication of redo included constipation with megarectosigmoid, residual presacral mass, anastomosis leak, and secondary fistula. ARM was corrected by excision of rectal stenosis, fistula, and its associated megarectosigmoid. This was followed by a complete surgical resection of the presacral tumor, with subsequent pull-through and anocolic anastomosis. This was done with a combined laparoscopic and transanal approach. The detailed surgical techniques, early postoperative complications, and mid-term functional outcomes were summarized. Results: Fourteen patients underwent LAARP for primary (N = 4) and redo (N = 10) repair of CS. Four of them had colostomy previously. Mean age at operation was 20.7 ± 13.9 months. Mean operative time was 120 ± 25 minutes. Median hospital stay was 8 days (range 7-9 days) postoperatively. None of the patients developed early postoperative complications such as anastomotic leaks, presacral abscesses, recurrent fistulas, and residual mass. Bowel function was assessed 1 year after LAARP in 10 patients. Mean follow-up time was 15.9 months. The frequency of bowel movements was 3.3 ± 1.5/day. Constipation occurred in 2 patients. Occasional soiling (<3 times/week) was reported in 4 patients and frequent soiling (>3 times/week) was in 1. Conclusion: LAARP for CS is safe and effective.

Laparoscopic surgical technique to enhance the management of anorectal malformations: 330 cases' experience in a single center

PURPOSE

Laparoscopic-assisted anorectoplasty (LAARP) is considered to benefit the patients with vesico-prostatic fistula. The aim of this study is to present the details of our LAARP technique for improving the short- and long-term outcomes in the patients with high and intermediate types of anorectal malformations (ARMs).

METHODS

330 patients with high-type (174 cases) and intermediate-type (156 cases) anorectal malformation (aged 8 days to 15 years) underwent LAARP from 2001 to 2019. LAARP was performed for full mobilization and resection of the dilated rectum, intra-rectal closure of the fistula, visualization, and enlargement of the center of the longitudinal muscle tube (LMT) from pelvic and perineal aspects.

RESULTS

LAARP was performed in all patients and no patient was converted to open procedure. The urethral diverticulum was found in three patients (1.02%, 3/294) according to postoperative protocol voiding cystourethrogram but was not associated with any symptoms such as urinary tract infection and dysuria. Rectal prolapse requiring surgical intervention developed in 25 (7.6%) of 330 patients. Anal stricture occurred in three patients and re-do anoplasty was performed 5 months after LAARP. Anal retraction occurred in two patients and re-pull-through was conducted at 5 and 6 days, respectively, after LAARP. 228 patients who were older than 3 years were followed up. The median follow-up period was 5.8 years (range 3-15 years). 217 patients (95.2%) had voluntary bowel movements; 202 patients (88.6%) were free from soiling or with grade 1 soiling; 30 patients (13.6%) and 25 patients (11.3%) suffered from grade 1 and grade 2 constipation, respectively, while no patient had grade 3 constipation.

CONCLUSION

Our experience demonstrates that the LAARP has advantages on rectal mobilization and resection, intra-rectal fistula closure and accurate tunnel formation in the LMT with minimal trauma. The improvement of the short-term and long-term outcomes after LAARP has been shown not only for high-type ARM but also for intermediate-type ARM.

Aberrant Expressions and Variant Screening of SEMA3D in Indonesian Hirschsprung Patients

Background: The semaphorin 3D (SEMA3D) gene has been implicated in the pathogenesis of Hirschsprung disease (HSCR), a complex genetic disorder characterized by the loss of ganglion cells in varying lengths of gastrointestinal tract. We wished to investigate the role of SEMA3D variants, both rare and common variants, as well as its mRNA expression in Indonesian HSCR patients. Methods: Sanger sequencing was performed in 54 HSCR patients to find a pathogenic variant in SEMA3D. Next, we determined SEMA3D expression in 18 HSCR patients and 13 anorectal malformation colons as controls by quantitative real-time polymerase chain reaction (qPCR). Results: No rare variant was found in the SEMA3D gene, except one common variant in exon 17, p.Lys701Gln (rs7800072). The risk allele (C) frequency at rs7800072 among HSCR patients (23%) was similar to those reported for the 1,000 Genomes (27%) and ExAC (28%) East Asian ancestry controls (p = 0.49 and 0.41, respectively). A significant difference in SEMA3D expression was observed between groups (p = 0.04). Furthermore, qPCR revealed that SEMA3D expression was strongly up-regulated (5.5-fold) in the ganglionic colon of HSCR patients compared to control colon (ΔC_T 10.8 ± 2.1 vs. 13.3 ± 3.9; p = 0.025). Conclusions: We report the first study of aberrant SEMA3D expressions in HSCR patients and suggest further understanding into the contribution of aberrant SEMA3D expression in the development of HSCR. In addition, this study is the first comprehensive analysis of SEMA3D variants in the Asian ancestry.

Involvement of proliferative and apoptotic factors in the development of hindgut in rat fetuses with ethylenethiourea-induced anorectal malformations

BACKGROUND

Anorectal malformations (ARMs) are common congenital malformations of the terminal digestive tract, but little is known regarding their pathogenesis. Aberrant cell proliferation/apoptosis are believed to be involved in ARMs. However, there are no studies on proliferation/apoptosis-related genes.

PURPOSE

We aimed to investigate the spatiotemporal expression patterns of two proliferation/apoptosis-related genes (MYC proto-oncogene and tumor protein p53) and explore their potential functions in the hindguts of ethylene thiourea-induced ARMs rat fetuses.

METHODS

MYC and p53 expression was evaluated using immunohistochemical staining, western blotting, and quantitative real-time polymerase chain reaction (RT-qPCR). Terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) and p53 costaining were performed to assay the colocalization of apoptotic and p53-expressing cells.

RESULTS

Rat fetuses with ARMs displayed fusion failure of the urogenital septum and cloacal membrane. In the control group, MYC was persistently expressed from gestational day (GD)14 to GD16 and distributed throughout the hindgut, while p53 was weakly detected in the terminal segment of the urethra and hindgut; in the ARMs group, MYC expression was obviously reduced, while p53 was widely and highly expressed in the urethra and hindgut. Western blotting and RT-qPCR confirmed the decrease in MYC and increase in p53 expression in ARMs. TUNEL and p53 co-staining revealed considerable overlap between apoptotic and p53-expressing cells.

CONCLUSION

The expression patterns of c-myc and p53 were disrupted in ARMs rat embryos, and the downregulation of c-myc and upregulation of p53 might be related to the development of ARMs at the key time points of ARMs morphogenesis.