Anorectal Malformations: Histomorphological and Immunohistochemical Evaluation of Neuronal Dysfunction

Interstitial Cells of Cajal and Ganglion Cell Distribution in Sigmoid Stomal Limbs and Distal Rectum after Stoma Formation in Male Anorectal Malformation Patients Undergoing Staged Repair

Introduction

This study was undertaken to assess the distribution of ganglion cells (GCs) and interstitial cells of Cajal (ICCs) across different points of distal rectal pouch in anorectal malformation (ARM) patients over the three stages of repair. We hypothesize that along with the surgical factors, there could be intrinsic factors as well which can be the cause of dysmotility in these patients after surgical repair.

Methodology

Full-thickness colonic biopsy specimens were taken from the proximal stoma, distal stoma, and distal rectal pouch of 21 boys aged 0-8 months undergoing 3 staged repair of ARM at our tertiary care center between August 2022 and December 2023. There was an interstage interval of approximately 12-14 weeks. All underwent high-divided sigmoid colostomy in stage 1. Biopsy specimens for GC and ICC number were routinely processed, and immunohistochemistry was done for CD117. The data was assessed and compared with respect to location and stage of surgery.

Results

Both GC and ICC showed a gradual decrease in mean number over three stages for both proximal and distal ends of colostomy. For proximal stoma, the distribution of either cell type did not differ across the stages, but for distal stoma, the number of cells was significantly lower in the second stage (following colostomy, before posterior sagittal anorectoplasty). However, no difference was noted between the second and third stages. This indicates that factors during/just after colostomy itself must be responsible for decrease in ICC/GC.

Conclusion

Lesser number of GC and/or ICC in the distal pouch from stage 2 onward may point toward its association with projected hypomotility in ARM patients. Apart from innate distribution, we also infer that this could be consequent to vascular insult which may occur at the time of divided colostomy. Loop stoma may be a better alternative as vascularity is uninterrupted in loop colostomy.

Effect of megarectum on postoperative defecation of female patients with congenital rectovestibular fistula or rectoperineal fistula

Background

To assess the effect of megarectum on postoperative defecation of female patients with congenital rectovestibular fistula or rectoperineal fistula.

Methods

From March 2013 to February 2021, 74 female patients with congenital rectovestibular fistula or rectoperineal fistula were treated. The age of patients ranged from 3 months to 1 year. Barium enema and spinal cord MRI were performed in all children. 4 patients were removed from the study because of spinal cord and sacral agenesis. Finally, 70 patients underwent one-stage anterior sagittal anorectoplasty (ASARP). Anal endoscopy and anorectal pressure measurement were performed 1 year after surgery. All patients were divided into two groups depending on the presence of megarectum (+) and (-) and observed for constipation and anal sphincter function.

Results

16 patients (4 months to 1 year) were complicated with megarectum, and 5 patients (3 months to 9 months) were without megarectum. The incision infection was seen in 3 patients. All patients were followed up for 1 year to 5 years. Fecal soiling was seen in 2 patients and constipation in 14 patients. Among 16 patients with megarectum, soiling was seen in 1 patient and the constipation in 12 patients. Among 54 patients without megarectum, soiling was seen in 1 patient and constipation in 2 patients. There was a significant difference in the incidence of postoperative constipation between the two groups (megarectum (+) 75% vs. megarectum (-) 3.7% (P < 0.05)). However, there was no significant difference in the score of anal sphincters between the two groups (P < 0.05). And there was no significant difference in anal resting pressure (P = 0.49) and length of anal high pressure area (P = 0.76). 7 patients with constipation and megarectum acquired normal anal function after the dilated rectum was resected.

Conclusion

Megarectum increases the possibility of difficult postoperative defecation in the patients with congenital rectovestibular fistula or rectoperineal fistula. However, constipation was not associated with ASARP postoperative effects on sphincter function. Resection of megarectum is helpful to the improvement of constipation.

Helicobacter pylori causes delayed gastric emptying by decreasing interstitial cells of Cajal

Helicobacter pylori (HP) infection is one of the most frequent bacterial infections in humans and is associated with the pathogenesis of gastric motility disorders such as delayed gastric emptying (DGE). Although HP infection is considered to delay gastric emptying, there has been little research on the underlying mechanism. Gastric motility involves interactions among gastrointestinal hormones, smooth muscle, enteric and extrinsic autonomic nerves and interstitial cells of Cajal (ICCs), and ICCs play an important role in gastrointestinal motility. Mutation or loss of stem cell factor (SCF) expression is known to reduce the number of ICCs or alter the integrity of the ICC network, contributing to gastrointestinal dysmotility. The aim of the present study was to investigate whether a reduction in ICCs contributes to the DGE caused by HP. A mouse model of HP infection was established and gastric emptying was compared between HP-infected and uninfected mice using the bead method. In addition, ICC counts and SCF expression levels in gastric tissue were evaluated using immunohistochemistry and western blotting, respectively. The results revealed that gastric emptying was significantly slower, the number of ICCs in gastric tissue was significantly reduced and the protein level of SCF in gastric tissue was significantly decreased in HP-infected mice compared with uninfected mice. Therefore, it may be concluded that HP reduced the number of ICCs by decreasing the expression of SCF protein in gastric tissue, thereby causing DGE.

[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.

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.

One-Stage Laparoscopic-Assisted Anorectoplasty for Neonates with Anorectal Malformation and Recto-Prostatic or Recto-Bulbar Fistula According to the Krickenbeck Classification

BACKGROUND

Congenital recto-urethral fistula (RUF) is the most common form of anorectal malformations (ARMs) found in boys. The aim of this study is to review our experience with one-stage laparoscopic procedure in the management of ARMs with recto-prostatic fistula and recto-bulbar fistula.

METHODS

Seventeen boys with congenital RUF who underwent one-stage laparoscopy-assisted anorectoplasty (LAARP) between July 2012 and June 2015 were retrospectively in the study.

RESULTS

All patients successfully underwent one-staged laparoscopic surgery without conversion. The recto-prostatic urethral fistula was encountered in 6 patients and recto-urethral bulbar fistula in 11 patients. The mean age at the time of surgery was 46.2 hours with mean length of hospital stay being 10.6 days. The operative times for the recto-urethral prostatic fistula and recto-urethral bulbar fistula were similar (128.2 versus 122.4 minutes, P = .091). Intraoperative blood loss was minimal. No injury to the urethra or vas deferens. The urethral catheter was removed on postoperative day 10. No one lost to follow-up. The median follow-up period was 2.6 years (range: 2-4 years). No recurrent fistula or urethral diverticulum was detected according to the voiding cystourethrography and pelvic MRI at 1 year.

CONCLUSION

One-stage LAARP is safe and effective for neonates with recto-prostatic fistula and recto-bulbar fistula. It provides an alternative method to rectify the ARMs with recto-prostatic fistula and recto-bulbar fistula without colostomy.