Clinicopathologic evaluation of congenital idiopathic megaesophagus in a Gordon Setter puppy: a case report and development and application of peripherin immunohistochemistry for detection of ganglion cells

We examined a case of congenital idiopathic megaesophagus (CIM) in a 5-wk-old female Gordon Setter puppy by means of contrast radiography, autopsy, histopathology, and immunohistochemistry. Clinical and radiologic findings included weight stagnation and marked generalized esophageal dilation with ventral displacement of the heart and lungs. These findings were confirmed at autopsy, and segments of the thoracic esophagus were sampled for histopathology. On histopathology, diffuse esophageal muscular atrophy, mucosal erosions, mononuclear inflammation, and a marked reduction in the number of myenteric plexus structures and number of ganglion cells were present (aganglionosis). The latter was determined immunohistochemically using an anti-peripherin antibody as the primary reagent, which provides a strong tool for the histologic confirmation of CIM. The histologic findings share some similarities to lesions associated with megaesophagus in Friesian foals, as well as esophageal achalasia and Hirschsprung disease in humans.

High-Resolution Anorectal Manometry as a Screening Tool for Hirschsprung's Disease: A Comprehensive Retrospective Analysis

Hirschsprung's disease (HD) is characterized by a congenital absence of enteric ganglion cells in the intestine, posing challenges in diagnosis, particularly in pediatric patients. The gold standard, rectal suction biopsy (RSB), carries risks, prompting an exploration of non-invasive alternatives such as high-resolution anorectal manometry (HR-ARM) for HD screening. We conducted a retrospective analysis of 136 patients suspected of HD between 2018 and 2022, which were stratified into three age groups: ≤12 months, ≤24 months, and >24 months. Criteria for suspicion included delayed meconium passage, unresponsive chronic constipation, and abnormal prior test results. HR-ARM, supplemented by additional tests, confirmed 16 HD cases. HR-ARM exhibited 93.75% sensitivity, 89.47% specificity, 99.03% negative predictive value (NPV), and 55.56% positive predictive value (PPV). Notably, HR-ARM consistently performed well in patients ≤ 2 years old but demonstrated reduced efficacy in older children, which was likely due to complications from chronic constipation. This study underscores HR-ARM's promise as a non-invasive HD screening tool, especially in younger patients. However, its limitations in older children warrant consideration. Establishing standardized protocols, particularly for assessing the recto-anal inhibitory reflex, is crucial. Further research is imperative to optimize HR-ARM's diagnostic role across varied age groups in HD assessment.

Diagnostic accuracy of barium enema versus full-thickness rectal biopsy in children with clinically suspected Hirschsprung's disease: A comparative cross-sectional study

Background and Aims

Hirschsprung's disease (HSD) remains a common cause of pediatric intestinal obstruction. Barium contrast enema (BE) is the primary imaging modality for the evaluation of clinically suspected cases. Here, we aimed to assess the diagnostic accuracy of BE in children with clinically suspected HSD when compared to a gold standard full-thickness rectal biopsy (FTRB).

Methods

We recruited and consecutively enrolled children with clinically suspected HSD at two tertiary teaching hospitals. Participants underwent BE imaging and two radiologists interpreted the findings independently. Participants further underwent FTRB by pediatric surgeons as the confirmatory test. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and receiver operating characteristics (ROC) with the area under the curve (AUC) were calculated on Stata version 14.2, taking FTRB as the standard.

Results

We enrolled 55 cases, of which 49 completed the evaluation and were included in the final analysis. The median age was 9.4 months (interquartile range: 2-24], with a male-to-female ratio of 4.4:1. The sensitivity, specificity, PPV, and NPV of BE were 0.95 (95% confidence interval [CI] [0.81-0.99]), 0.73 (95% CI [0.39-0.94]), 0.92 (95% CI [0.82-0.97]), and 0.80 (95% CI [0.50-0.94]), respectively. On AUC, the diagnostic accuracy of BE compared to the confirmatory FTRB was 0.84 (95% CI [0.69-0.98]). The diagnostic accuracy was higher in neonates (ROC: 1.00) when compared to infants (ROC: 0.83) or those above 1 year of age (ROC: 0.798). HSD-suggestive BE findings were associated with absence of ganglion cells on FTRB (χ 2 = 23.301, p < 0.001). Inverted rectosigmoid ratio and transition zone were more sensitive in detecting HSD of 0.92 (95% CI [0.74-0.98]) and 0.81 (95% CI [0.63-0.92]), respectively.

Conclusion

BE is sufficiently accurate in the diagnosis of children with HSD, suggesting BE would likely be used to inform surgical management in settings where confirmatory biopsy is lacking. However, clinical judgment is warranted in interpreting negative BE findings.

Impact of cryopreservation on viability, gene expression and function of enteric nervous system derived neurospheres

Introduction: Impairment of both the central and peripheral nervous system is a major cause of mortality and disability. It varies from an affection of the brain to various types of enteric dysganglionosis. Congenital enteric dysganglionosis is characterized by the local absence of intrinsic innervation due to deficits in either migration, proliferation or differentiation of neural stem cells. Despite surgery, children's quality of life is reduced. Neural stem cell transplantation seems a promising therapeutic approach, requiring huge amounts of cells and multiple approaches to fully colonize the diseased areas completely. A combination of successful expansion and storage of neural stem cells is needed until a sufficient amount of cells is generated. This must be combined with suitable cell transplantation strategies, that cover all the area affected. Cryopreservation provides the possibility to store cells for long time, unfortunately with side effects, i.e., upon vitality. Methods: In this study we investigate the impact of different freezing and thawing protocols (M1-M4) upon enteric neural stem cell survival, protein and gene expression, and cell function. Results: Freezing enteric nervous system derived neurospheres (ENSdN) following slow-freezing protocols (M1-3) resulted in higher survival rates than flash-freezing (M4). RNA expression profiles were least affected by freezing protocols M1/2, whereas the protein expression of ENSdN remained unchanged after treatment with protocol M1 only. Cells treated with the most promising freezing protocol (M1, slow freezing in fetal calf serum plus 10% DMSO) were subsequently investigated using single-cell calcium imaging. Freezing of ENSdN did not alter the increase in intracellular calcium in response to a specific set of stimuli. Single cells could be assigned to functional subgroups according to response patterns and a significant shift towards cells responding to nicotine was observed after freezing. Discussion: The results demonstrate that cryopreservation of ENSdN is possible with reduced viability, only slight changes in protein/gene expression patterns and without an impact on the neuronal function of different enteric nervous system cell subtypes, with the exception of a subtle upregulation of cells expressing nicotinergic acetylcholine receptors. In summary, cryopreservation presents a good method to store sufficient amounts of enteric neural stem cells without neuronal impairment, in order to enable subsequent transplantation of cells into compromised tissues.

Ileal atresia and total colonic hirschsprung disease in a 36-week neonate: A case report

Intestinal atresia and hirschsprung disease are two common causes of bowel obstruction in neonates; simultaneous occurrence is rare. This report delineates a 36-week newborn with ileal atresia and total colonic hirschsprung who was referred to our unit due to failure of meconium passage during the first 48 h after birth.

Reoperation for Hirschsprung Disease: Two cases of Vanishing Ganglion Cells and Review of the Literature

Hirschsprung disease (HD) is characterized by circumferential aganglionosis of the rectum with variable proximal bowel involvement. The underlying pathogenesis is due to failure of caudal migration of neural crest cells during pre-natal development, causing functional bowel obstruction. Definitive therapy is surgical resection; however, a subset of patients will require reoperation. An important cause of reoperation is the rare but distinct entity described as the ganglion cell "vanishing" phenomenon. In this phenomenon, affected patients have normal circumferential ganglion cells present at the proximal margin during primary resection. They undergo a variable asymptomatic period post-primary resection but ultimately develop recurrent symptoms. Upon reoperation, ganglion cells seemingly vanish and are no longer present in the previously functioning and ganglionated bowel proximal to the initial anastomotic site. To further characterize and investigate this poorly understood pathology, here we present 2 cases of HD patients who required reoperation. Our small series implicates that an immune component may contribute as patient 2 had a brisk neurotrophic eosinophilic infiltrate only present in the reoperation specimen. However, this was not observed in patient 1. Other possible etiologies include post-operative ischemia/hypoxia, visceral neuropathy, or signaling abnormalities within the residual ganglion cells themselves.

Long-term Bowel function and pediatric health-related quality of life after transanal rectal mucosectomy and partial internal anal sphincterectomy pull-through for Hirschsprung Disease

OBJECTIVE

The aim of this study was to define controlled outcomes for bowel function and quality of life (QoL) after transanal rectal mucosectomy and partial internal anal sphincterectomy pull-through (TRM-PIAS, A modified Swenson procedure) for Hirschsprung disease (HD).

BACKGROUND

We have previously shown that a novel modification of transanal rectal mucosectomy and partial internal anal sphincterectomy (TRM-PIAS, A modified procedure) for Hirschsprung disease have the advantage of low postoperative Hirschsprung associated enterocolitis. The controlled long-term follow-up studies evaluating Bowel Function Score (BFS) and Pediatric Quality of Life Inventory (PedsQoL, age <18 years) remain unclear.

METHODS

Between Jan 2006 and Jan 2016, 243 Patients underwent TRM-PIAS older than 4 years were included, while experienced redo surgery because of complication were excluded. Patients were compared with age- and gender-matched 244 healthy children each randomly selected from the 405 general population. The enrollee was investigated for questionnaires on BFS and PedsQoL.

RESULTS

One hundred and ninety-nine (81.9%) patients' representatives for the entire study population responded. The mean age of patients was 84.4 months (48-214 months). Compared with controls, patients reported impairment of hold back defecation, fecal soiling, and the urge to defecate (P < 0.05), and no significantly different in fecal accidents, constipation and social problems. With advancing age, the total BFS of HD patients improved, with a tendency close to the normal level beyond 10 years old. But, after grouped according to presence or absence of HAEC, the non-HAEC group experienced more dramatic improvement with age increasing.

CONCLUSIONS

Compared with matched peers, significant impairment of fecal control prevails after TRM-PIAS in HD patients, but bowel function improve with age and recovery faster than conventional procedure. It should be emphasized that post-enterocolitis is a high-risk factor for delayed recovery.

Children with Hirschsprung disease in a developing country: A cohort study of the predictors of a positive rectal biopsy result

Chronic constipation, which may be habitually or pathologically caused, is one of the most common complaints in children. One of the important pathological causes is Hirschsprung's disease (HD), which is diagnosed via multiple modalities, mainly rectal biopsy. Our aim was to compare the presentation and different predictive factors for positive rectal biopsy results in a developing country in the Middle East, such as Jordan. This cohort study was conducted at the Jordan University Hospital (JUH). All consecutive children aged <14 years who presented with refractory constipation and underwent rectal biopsies between January 2014 and December 2019 were retrospectively enrolled in the study. In the entire cohort study, 79 patients were enrolled: 45 (57%) were males and 34 (43%) were females. Regarding the biopsy results, 51 (64.6%) cases of refractory constipation without HD and 28 (35.4%) patients with refractory constipation with HD were diagnosed with open rectal biopsies. The male-to-female ratio of HD patients was 3:1. Moreover, 3 (10.7%) children who passed the meconium within the first 24 to 48 hours showed features of HD, while 17 (60.7%) children with delayed passage of the meconium showed features of HD. Abdominal distension was found to be a positive predictor of positive biopsy results (odds ratio [OR] = 4.09, P = .011), and soiling was found to be a negative predictor of positive biopsy results (OR = 0.07, P = .024). In developing countries, children presenting with HD seem to have similar symptoms and signs to those observed with traditional sampling and staining techniques.

Surgical Reconstruction Options for a Case of Near Total Intestinal Aganglionosis

Hirschsprung's disease is a congenital anomaly affecting neural crest cell migration and proliferation in the myenteric plexi resulting in dysmotility, which can present as bilious emesis, delayed meconium passage, and bowel obstruction in neonates, or chronic constipation in older children. Depending on the extent of aganglionosis, this disease can involve the whole gut. Treatment involves a temporary ostomy and interval definitive surgical reconstruction. In patients with near or total intestinal aganglionosis, however, there is no consensus on the most effective surgical reconstruction as consideration of the length and function of the normal remnant bowel create concerns for complications with short bowel syndrome post-operatively. We present a case of near-total intestinal aganglionosis highlighting the various options for definitive surgical reconstruction.

Submucosal Nerve Diameter in the Rectum Increases With Age: An Important Consideration for the Diagnosis of Hirschsprung Disease

INTRODUCTION

Hypertrophic submucosal nerves, defined as ≥40 µm in diameter, are considered supportive of a diagnosis of HSCR, but the effect of age on nerve diameter has not been well-studied. We sought to determine the distribution of the largest nerve diameter in ganglionic rectal biopsies and the significance of hypertrophic submucosal nerves in the diagnosis of Hirschsprung disease (HSCR) based on age.

METHODS

Rectal biopsies performed in the evaluation of HSCR were retrospectively reviewed from 179 patients (151 ganglionic biopsies, 28 aganglionic biopsies), and the diameter of the largest submucosal nerve was measured.

RESULTS

In non-Hirschsprung disease (non-HSCR) biopsies, submucosal nerve diameter increased with age. In patients <1 year, the average diameter was 34.1 ± 11.6 µm but increased to 50.8 ± 17.3 µm after 1 year of age. Submucosal nerves ≥40 µm in diameter were significantly associated with HSCR across all ages [HSCR = 25/28 (89.3%) vs non-HSCR = 59/151 (39.1%), p < 0.0001] and remained significant in patients <1 year of age [HSCR = 22/24 (91.7%) vs non-HSCR = 19/91 (20.9%), p < 0.0001].

CONCLUSIONS

The diameter of submucosal nerves increases with age, and ≥40 µm nerves are common after 1 year of age.

Functional Outcomes After Surgery for Total Colonic, Long-Segment, Versus Rectosigmoid Segment Hirschsprung Disease

OBJECTIVES

Knowledge on long-term outcomes in patients with Hirschsprung disease is progressing. Nevertheless, differences in outcomes according to aganglionic lengths are unclear. We compared long-term bowel function and generic quality of life in Hirschsprung patients with total colonic or long-segment versus rectosigmoid aganglionosis.

METHODS

In this nationwide, cross-sectional study participants with proven Hirschsprung disease received the Defecation and Fecal Continence questionnaire, and the Child Health Questionnaire Child Form-87, or the WHO Quality of Life-100. We excluded deceased patients, patients who were younger than 8 years, lived abroad, had a permanent enterostomy, or were intellectually impaired.

RESULTS

The study population (n = 334) was operated for rectosigmoid (83.9%), long-segment (8.7%), or total colonic aganglionosis (7.5%). Fecal incontinence in general was not significantly different between the three groups, but liquid fecal incontinence was significantly associated with total colonic aganglionosis (odds ratio [OR] = 6.00, 95% confidence interval [CI] 2.07-17.38, P = 0.001). Regarding constipation, patients with total colonic or long-segment aganglionosis were less likely to suffer from constipation than the rectosigmoid group (OR = 0.21, 95% CI, 0.05-0.91, P = 0.038 and OR = 0.11, 95% CI, 0.01-0.83, P = 0.032). Quality of life was comparable between the three groups, except for a lower physical score in children with total colonic aganglionosis (P = 0.016).

CONCLUSIONS

Over time Hirschsprung patients with total colonic or long-segment aganglionosis do not suffer from worse fecal incontinence in general. A difference in stool consistency may underlie the association between liquid fecal incontinence and total colonic aganglionosis and constipation in patients with rectosigmoid aganglionosis. Despite these differences, generic quality of life is comparable on reaching adulthood.

Autopsy Study of Calretinin Immunohistochemistry in the Anorectal Canal in Young Infants and Potential Implications for Rectal Biopsy Approach in the Neonatal Period

BACKGROUND

Absent submucosal ganglion cells in biopsies 1-3 cm above the pectinate line establishes the pathologic diagnosis of Hirschsprung Disease (HD). Calretinin stains both ganglion cells and their mucosal neurites and has gained importance in HD diagnosis. Absent calretinin positive mucosal neurites in biopsies at the appropriate level above the pectinate line is highly specific for HD. Whether this applies to lower biopsies is uncertain. To address this, we studied anorectal canal autopsy specimens from infants.

METHODS

We performed an autopsy study of infant anorectal canal specimens to describe calretinin staining in this region. Calretinin staining was correlated with histologic and gross landmarks.

RESULTS

In all 15 non-HD specimens, calretinin positive mucosal neurites were present in glandular mucosa up to the anorectal line where neurites rapidly diminished. Age range was preterm 26 weeks to 3 months.

CONCLUSIONS

Calretinin positive mucosal neurites are present in glandular mucosa up to the anorectal line in young infants. This is potentially important regarding neonatal HD biopsy level and diagnosis. Positive calretinin staining at the anorectal line favors normal innervation making HD unlikely. Absent calretinin positive neurites in glandular mucosa is worrisome for HD in young infants, regardless of location.

Alterations of Gut Bacteria in Hirschsprung Disease and Hirschsprung-Associated Enterocolitis

Hirschsprung-associated enterocolitis (HAEC) is a common life-threatening complication of Hirschsprung disease (HSCR). It has been proposed that gut microbiota, which have an essential role in gut-homeostasis, are associated with HAEC. Recent studies demonstrated an increase in alpha diversity of fecal microbiota over time in HSCR mice and a decrease in diversity after surgery. In addition, clinical studies have reported a reduction in bacterial richness in HSCR children after surgery. Some studies revealed a difference in microbiota between the proximal ganglionic and distal aganglionic intestine and found a difference in bacterial character between fecal and colonic specimens. HAEC studies found an increase in Proteobacteria, especially Escherichia and Enterobacteriaceae, with a decrease in Firmicutes and Bifidobacterium in HAEC patients. However, the direction of alpha diversity in HAEC patients is still controversial. The self-comparison of microbiota in treatment periods suggested that probiotics might improve gut dysbiosis and decrease the frequency of enterocolitis, but some reported contradictory findings. This review comprehensively summarizes and discusses key findings from animal and clinical data of the distinct microbiome associated with HCSR and the association of gut dysbiosis with the development of HAEC. This information should be useful in the establishment of novel interventions to improve gut dysbiosis and prevent enterocolitis in HSCR patients.

Reoperative techniques and management in Hirschsprung disease: a narrative review

The majority of children who undergo operative management for Hirschsprung disease have favorable results. A subset of patients, however, have long-term dysfunctional stooling, characterized by either frequent soiling or obstructive symptoms. The evaluation and management of a child with poor function after pull-through for Hirschsprung disease should be conducted by an experienced multidisciplinary team. A systematic workup is focused on detecting pathologic and anatomic causes of pull-through dysfunction. This includes an exam under anesthesia, pathologic confirmation including a repeat biopsy, and a contrast enema, with additional studies depending on the suspected etiology. Obstructive symptoms may be due to technique-specific types of mechanical obstruction, histopathologic obstruction, or dysmotility-each of which may benefit from reoperative surgery. The causes of soiling symptoms include loss of the dentate line and damage to the anal sphincter, which generally do not benefit from revision of the pull-through, and pseudo-incontinence, which may reveal underlying obstruction. A thorough understanding of the types of complications associated with various pull-through techniques aids in the evaluation of a child with postoperative dysfunction. Treatment is specifically tailored to the patient, guided by the etiology of the patient's symptoms, with options ranging from bowel management to redo pull-through procedure. This review details the workup and management of patients with complications after pull-through, with a focus on the perioperative management and technical considerations for those who require reoperation.

The Emerging Genetic Landscape of Hirschsprung Disease and Its Potential Clinical Applications

Hirschsprung disease (HSCR) is the leading cause of neonatal functional intestinal obstruction. It is a rare congenital disease with an incidence of one in 3,500-5,000 live births. HSCR is characterized by the absence of enteric ganglia in the distal colon, plausibly due to genetic defects perturbing the normal migration, proliferation, differentiation, and/or survival of the enteric neural crest cells as well as impaired interaction with the enteric progenitor cell niche. Early linkage analyses in Mendelian and syndromic forms of HSCR uncovered variants with large effects in major HSCR genes including RET, EDNRB, and their interacting partners in the same biological pathways. With the advances in genome-wide genotyping and next-generation sequencing technologies, there has been a remarkable progress in understanding of the genetic basis of HSCR in the past few years, with common and rare variants with small to moderate effects being uncovered. The discovery of new HSCR genes such as neuregulin and BACE2 as well as the deeper understanding of the roles and mechanisms of known HSCR genes provided solid evidence that many HSCR cases are in the form of complex polygenic/oligogenic disorder where rare variants act in the sensitized background of HSCR-associated common variants. This review summarizes the roadmap of genetic discoveries of HSCR from the earlier family-based linkage analyses to the recent population-based genome-wide analyses coupled with functional genomics, and how these discoveries facilitated our understanding of the genetic architecture of this complex disease and provide the foundation of clinical translation for precision and stratified medicine.

Skip Segment Hirschsprung Disease Managed by Pull-Through of the Right Colon

Hirschsprung disease is the most common neurocristopathy in children, resulting in the congenital loss of enteric ganglia. Rare reports of skip lesions have previously been reported in the literature. We present a case of skip lesions known prior to surgery and managed by pull-through of the right colon that allowed the preservation of the colon.

Diagnostic Role of Calretinin in Suspicious Cases of Hirschsprung's Disease

Background Hirschsprung's disease (HD) is a developmental disorder of the intrinsic component of the enteric nervous system. It is characterized by the absence of ganglion cells in the myenteric and submucosal plexus. Histopathological diagnosis becomes difficult many times due to submucosal ganglionic cells are not easily identifiable. Aims and objective The aim of this study was to examine the clinical and histopathological features of HD and to establish the utility of calretinin staining to diagnose the case of suspicious HD. Materials and methods After taking necessary informed consent, we studied 41 cases in which clinical suspicion of HD had been made, in a study duration of three years (July 2017-June 2020). Open biopsies were taken from spastic segment, transition zone and dilated segment. Histopathological diagnosis had been made in three categories: HD, no Hirschsprung's disease (NHD) and suspicion of HD. Post histopathological diagnosis calretinin immunohistochemistry (IHC) was applied to all cases and interpretations were noted. Results On the basis of histopathological findings, 25 cases were diagnosed as HD, nine cases were marked for suspicion for HD and seven cases as NHD. After evaluating calretinin IHC on the suspicious case, total of 30 cases were confirmed as HD while the remaining 11 cases were confirmed as NHD. Twenty-four patients of HD were males while the remaining six cases were females. The age of patients ranged from four days to 10 years. Median age six days while 22 patients were in the neonatal period. Conclusion Calretinin immunostaining is a useful modality in diagnosing suspicious cases of HD. Its results are easy to interpret by less experienced pathologist with accuracy.

Ultrashort-segment Hirschsprung disease in a 4-year-old female

Hirschsprung disease (HSCR) is characterized by the absence of neuronal ganglion cells in a distal portion of the intestinal tract [1]. In 1691, Frederick Ruysch described the disease as congenital megacolon. HSCR-associated congenital anomalies have been reported in 5–32% of affected patients [2]. The clinical symptoms of HSCR are usually evident in the neonatal period. However, in some cases where the extent of the aganglionic segment is short, symptoms may become clinically relevant later in childhood [3]. HSCR is one of the most difficult diseases to identify in pediatric surgery due to its multiple clinical, histological and radiological variations [2, 3]. The goal of surgical management is to remove the aganglionic segment and reconstruct the intestinal tract through techniques such as Swenson, Duhamel and Soave [4]. The following case consists of a 4-year-old patient with a chronic presentation of constipation secondary to ultrashort-segment Hirschsprung disease.

Pathogenesis of chronic constipation in a Polish group of paediatric patients - an attempt to create the optimal histopathological diagnostic protocol

Introduction

Histopathological diagnosis of chronic constipation in children is difficult and time-consuming because the aetiology of the problem is heterogenous.

Aim

To create the optimal immunohistochemical (IHC) and histological diagnostic protocol using novel antibodies and assessing precisely their patterns.

Material and methods

Twenty-eight paediatric patients were enrolled to the study. The study group consisted of the following: 9 patients with confirmed Hirschsprung’s disease (HD), 11 patients with desmosis of the colon (DC) (3) or with chronic constipation of unknown aetiology (3), and eight children operated on due to other problems. Retrospective analysis of full-thickness material from the large intestine was performed. In each specimen the number of ganglion cells was estimated per square millimetre as well as the number of submucosal and intramuscular ganglion cells per ganglion. The following IHC and histological stains were also performed: calretinin, CD117, picrosirius, and trichrome gomori. Patterns (nuclear vs. cytoplasmic vs. membranous) and intensity (strong vs. faint) of the stainings were analysed.

Results

There was no statistically significant difference between groups while comparing the intensity and pattern of each staining, except HD (no staining due to lack of ganglion cells), p > 0.001. Calretinin was positive in each patient with ganglion cells; however, it did not unequivocally stain all cells identified in routine haematoxylin and eosin staining.

Conclusions

Calretinin is helpful in identifying ganglion cells; however, it cannot replace an experienced paediatric pathologist. In children with chronic constipation it is worth obtaining a full thickness intestinal biopsy in order to perform additional histological and immunohistochemical stains starting with picrosirius red.

Congenital Segmental Intestinal Dilatation: A 25-Year Review with Long-Term Follow-up at the Medical University of Innsbruck, Austria

Background and Aim  Congenital segmental intestinal dilatation (CSID) is a neonatal condition with unclear etiology and pathogenesis. Typically, the newborn with CSID presents with a limited (circumscribed) bowel dilatation, an abrupt transition between normal and dilated segments, neither intrinsic nor extrinsic perilesional obstruction, and no aganglionosis or neuronal intestinal dysplasia. We aimed to review this disease and the long-term follow-up at the Children's Hospital of the Medical University of Innsbruck, Tyrol, Austria. Study Design  Retrospective 25-year review of medical charts, electronic files, and histopathology of neonates with CSID. Results  We identified four infants (three girls and one boy) with CSID. The affected areas included duodenum, ileum, ascending colon, and sigmoid colon. Noteworthy, all patients presented with a cardiovascular defect, of which two required multiple cardiac surgical interventions. Three out of the four patients recovered completely. To date, the three infants are alive. Conclusion  This is the first report of patients with CSID and cardiovascular defects. The clinical and surgical intervention for CSID also requires a thorough cardiologic evaluation in these patients. CSID remains an enigmatic entity pointing to the need for joint forces in identifying common loci for genetic investigations.

Clinicopathological Characteristics of Hirschsprung's Disease With Emphasis on Diagnosis and Management: A Single-Center Study in the Kingdom of Saudi Arabia

Introduction: Hirschsprung’s Disease (HD) is a motor disorder of the gut caused by the failure of neural crest cells to migrate craniocaudally into the bowel during intestinal development, resulting in a functional obstruction. The majority of patients with HD are diagnosed in the neonatal period when they present with symptoms of distal intestinal obstruction. Aim: This study aims to identify the clinic-pathological characteristic of HD patients in our institution in KSA and comparing it with local and international data. Materials and Methods: This retrospective cohort study was conducted in King Abdulaziz Medical City (KAMC), a tertiary care center in Riyadh, Kingdome of Saudi Arabia (KSA). Results: A total of 54 patients (72% male) were diagnosed with HD. Forty-eight patients (89%) were born at term, and 6 were pre-term. Sixty-three percent of the patients presented in the neonatal period. Twenty-two patients (41%) underwent one-stage endorectal pull-through procedure, 23 patients (43%) two-stage endorectal pull-through, and 9 patients (16%) had three-stage endorectal pull-through. Five out of 54 patients had ganglion cells seen on FS but were absent in the permanent section. Therefore, the concordance rate was 90.8%. Conclusion: FS biopsy is a necessary method to determine the level of aganglionosis intraoperatively in HD, but the definitive diagnosis should be with permanent section. Also, the choice of surgical operation type (single-stage or multi-stage pull-through) depends on the patient’s clinical condition.

B-lymphocyte-intrinsic and -extrinsic defects in secretory immunoglobulin A production in the neural crest-conditional deletion of endothelin receptor B model of Hirschsprung-associated enterocolitis

Hirschsprung disease (HSCR) is a common cause of intestinal obstruction in the newborn. Hirschsprung-associated enterocolitis (HAEC) is a significant and life-threatening complication of HSCR, affecting up to 60% of patients. Animal models of endothelin receptor B (EdnrB) mutation reliably model human HSCR and HAEC. We previously demonstrated intestinal dysbiosis and a gut-specific deficiency of B-lymphocyte-produced secretory IgA (sIgA), the primary effector molecule of mucosal immunity, in mice with homozygous neural crest cell-conditional deletion of EdnrB (EdnrB^NCC-/-). To determine mechanisms for sIgA deficiency, we examined intrinsic and extrinsic aspects of B-lymphocyte development and function. Expression of the endothelin axis components [endothelin-1 (ET-1), endothelin-3 (ET-3), endothelin receptor A (EdnrA), EdnrB] were determined over a developmental time course. B-lymphocyte survival and Ig production were assayed in vitro. Polymeric Ig receptor (pIgR)-mediated IgA transport into the intestinal lumen was interrogated. We found endothelin axis component (EdnrA, EdnrB, ET-1, ET-3) expression in developing extramedullary hematopoietic organs and that some splenic B lymphocytes express EdnrB. Splenic B lymphocytes from EdnrB^NCC-/- mice showed no intrinsic defect in survival vs. wild-type (WT) B lymphocytes. In vitro stimulation of splenic B lymphocytes demonstrated decreased IgA, IgG, and IgM production in EdnrB^NCC-/- vs. WT mice. Additionally, small intestinal pIgR was decreased ∼50% in EdnrB^NCC-/- mice. These results suggest an intrinsic B-lymphocyte defect in antibody production as well as an extrinsic defect in IgA transport in the EdnrB^NCC-/- model of HAEC. Our results are consistent with human HAEC observations of decreased luminal sIgA and mouse models of other inflammatory bowel diseases, in which decreased pIgR is seen in concert with a dysregulated microbiota. Finally, our results suggest targeting the dysbiotic microbiome and pIgR-mediated sIgA transport as potential therapeutic approaches in prevention and treatment of HAEC.-Medrano, G., Cailleux, F., Guan, P., Kuruvilla, K., Barlow-Anacker, A. J., Gosain, A. B-lymphocyte-intrinsic and -extrinsic defects in secretory immunoglobulinA production in the neural crest-conditional deletion of endothelin receptor B model of Hirschsprung-associated enterocolitis.

A Metagenomics Study on Hirschsprung's Disease Associated Enterocolitis: Biodiversity and Gut Microbial Homeostasis Depend on Resection Length and Patient's Clinical History

Objectives: Since 2010, several researches demonstrated that microbiota dynamics correlate and can even predispose to Hirschsprung (HSCR) associated enterocolitis (HAEC). This study aims at assessing the structure of the microbiota of HSCR patients in relation to extent of aganglionosis and HAEC status. Methods: All consecutive HSCR patients admitted to Gaslini Institute (Genova, Italy) between May 2012 and November 2014 were enrolled. Institutional review board (IRB) approval was obtained. Stools were sampled and 16S rDNA V3-V4 regions were sequenced using the Illumina-MiSeq. Taxonomy assignments were performed using QIIME RDP. Alpha diversity indexes were analyzed by Shannon and Simpson Indexes, and Phylogenetic Diversity. Results: We enrolled 20 patients. Male to female ratio was 4:1. Six patients suffered from Total Colonic Aganglionosis (TCSA). Considering sample site (i.e., extent of aganglionosis), we confirmed the known relationship between sample site and both biodiversity and composition of intestinal microbiota. Patients with TCSA showed lower biodiversity and increased Proteobacteria/Bacteroidetes relative abundance ratio. When addressing biodiversity, composition and dynamics of TCSA patients we could not find any significant relationship with regard to HAEC occurrences. Conclusions: The composition of HAEC predisposing microbiota is specific to each patient. We could confirm that total colon resections can change the composition of intestinal microbiota and to dramatically reduce microbial diversity. The subsequent reduction of system robustness could expose TCSA patients to environmental microbes that might not be part of the normal microbiota. Future long-term studies should investigate both patients and their family environment, as well as their disease history.

Ethnic variations in the childhood prevalence of Hirschsprung disease in New Zealand

BACKGROUND

Epidemiological studies have suggested that there may be ethnic variations in the prevalence of Hirschsprung disease (HD) but no study has systematically investigated this issue or potential ethnic variations in the extent of aganglionosis in HD. This study aimed to investigate this in a childhood population in New Zealand.

METHODS

A multicentre national retrospective review was undertaken of all newly diagnosed cases of HD at each of the four paediatric surgical centres in New Zealand over a 16-year period (January 2000 to December 2015). Original histological, radiological and operative reports were obtained and analysed. Self-identified ethnicity was recorded from admission documents. Birth statistics were obtained from Statistics New Zealand.

RESULTS

A total of 246 cases of HD were identified. The prevalence of HD was 1:3790 live births for European, 1:6610 among Māori, 1:1834 among Pacific Peoples, 1:3847 among Asian and 1:5694 among Middle Eastern. The prevalence of HD was statistically significantly greater in Pacific Peoples (P < 0.0005). The proportion of children with long-segment HD was also significantly greater in Pacific and Asian populations than others (P = 0.04). These findings were not due to differences in the proportion of familial cases of HD among the different populations.

CONCLUSIONS

The prevalence and phenotype of HD varies significantly between different ethnic groups within New Zealand. This may well be related to variations in the frequencies of HD-associated gene mutations within these populations.

Spectrum of Clinicopathological Deviations in Long-Segment Hirschsprung Disease Compared With Short-Segment Hirschsprung Disease: A Single-Institution Study

Hirschsprung disease (HSCR) is a congenital disorder characterized by intestinal aganglionosis leading to pseudoobstruction. The majority of cases are limited to the rectum or rectosigmoid (S-HSCR). A variably longer segment can be affected (L-HSCR), which may show many deviations from S-HSCR. We retrospectively reviewed 48 clinicopathologically confirmed total cases of HSCR at a single institution in a 21-year period to identify L-HSCR cases and determine their deviations from known features of S-HSCR. Eight L-HSCR cases were found where aganglionosis extended to the terminal ileum (7/8) or to the splenic flexure (1/8). L-HSCR lacked male preponderance and was in contrast more common in females (6/8). Associated anomalies included congenital heart disease (2) and neonatal hypothyroidism (1), previously underreported associations. The clinical diagnosis of L-HSCR was often delayed (average age at diagnosis 13 days) and the diagnosis was more often made operatively (5/8) rather than on rectal suction biopsy (3/8). Histologically, apart from aganglionosis, neural hyperplasia was either absent or focal, compounding the diagnostic difficulty. Although the number of cases in our study was limited due to the rarity of L-HSCR, this study still highlights the spectrum of deviations of L-HSCR from known clinicopathological features of S-HSCR.

Distal Rectal Skip-Segment Hirschsprung Disease and the Potential for False-Negative Diagnosis

In skip-segment Hirschsprung disease (SS-HSCR), an aganglionic segment of bowel, which extends proximally from the distal rectum, is interrupted by a ganglionated "skip segment." Skip segments are usually located far proximal to the rectum where they do not interfere with initial diagnosis, although the possibility of distal SS-HSCR should be considered during interpretation of intraoperative biopsies or patients with atypical postoperative courses. We report 2 cases of SS-HSCR with skip areas in the distal rectum, 1 of which led to a false-negative diagnosis by suction rectal biopsy. These 2 cases of SS-HSCR, along with others in the literature, highlight the point that ganglionic skip segments can confuse clinicians and lead to inadequate bowel resection, diagnostic delay, or a false-negative diagnosis. The pathogenesis of SS-HSCR is discussed in light of recent discoveries regarding transmesenteric migration of vagal neural crest cells and the role of sacral neural crest cells in hindgut neurodevelopment.

Hirschsprung's associated enterocolitis

PURPOSE OF REVIEW

Hirschsprung's disease (HSCR) is characterized by an absence of ganglion cells in the distal hindgut, extending from the rectum to a variable distance proximally, and results from a failure of cranial-caudal neural crest cell migration. Hirschsprung's-associated enterocolitis (HAEC) is a condition with classic manifestations that include abdominal distention, fever and foul-smelling stools, and is a significant and life-threatening complication of HSCR. The purpose of this review was to critically evaluate recent findings regarding the pathophysiology of HAEC.

RECENT FINDINGS

Several recent studies have investigated the cause of HAEC in humans and mouse models. These studies suggest that alterations in the intestinal barrier, including goblet cell number and function, and Paneth cell function, impaired gastrointestinal mucosal immunity, including B-lymphocyte trafficking or function and secretory immunoglobulin A production, and dysbiosis of the intestinal microbiota may contribute to the development of HAEC.

SUMMARY

Recent studies add to the body of literature, suggesting that the intestinal defects observed in HSCR are not restricted to the aganglionic segment but extend to the mucosal immune system within and beyond the gastrointestinal tract. Future studies further dissecting the mechanisms of HAEC and validating these findings in humans will allow for the development of directed therapeutic interventions.

Enteric neuron imbalance and proximal dysmotility in ganglionated intestine of the Sox10Dom/+ Hirschsprung mouse model

BACKGROUND & AIMS

In Hirschsprung disease (HSCR), neural crest-derived progenitors (NCPs) fail to completely colonize the intestine so that the enteric nervous system (ENS) is absent from distal bowel. Despite removal of the aganglionic region, many HSCR patients suffer from residual intestinal dysmotility. To test the hypothesis that inappropriate lineage segregation of NCPs in proximal ganglionated regions of the bowel could contribute to such postoperative disease, we investigated neural crest (NC)-derived lineages and motility in ganglionated, postnatal intestine of the Sox10Dom/+ HSCR mouse model.

METHODS

Cre-mediated fate-mapping was applied to evaluate relative proportions of NC-derived cell types. Motility assays were performed to assess gastric emptying and small intestine motility while colonic inflammation was assessed by histopathology for Sox10Dom/+ mutants relative to wildtype controls.

RESULTS

Sox10Dom/+ mice showed regional alterations in neuron and glia proportions as well as Calretinin+ and nNOS+ neuronal subtypes. In the colon, imbalance of enteric NC derivatives correlated with the extent of aganglionosis. All Sox10Dom/+ mice exhibited reduced small intestinal transit at 4-weeks of age, and at 6-weeks, Sox10Dom/+ males had increased gastric emptying rates. Sox10Dom/+ mice surviving to 6-weeks of age had little or no colonic inflammation when compared to wildtype littermates, suggesting that these changes in GI motility are neurally mediated.

CONCLUSIONS

The Sox10Dom mutation disrupts the balance of NC-derived lineages and affects GI motility in the proximal, ganglionated intestine of adult animals. This is the first report identifying alterations in enteric neuronal classes in Sox10Dom/+ mutants, which suggests a previously unrecognized role for Sox10 in neuronal subtype specification.

Advances in Hirschsprung disease genetics and treatment strategies: an update for the primary care pediatrician

Hirschsprung disease (HSCR) is a multigenic condition with variable presentation. Most commonly, it presents in the neonatal period as a functional intestinal obstruction secondary to failure of caudal migration of the enteric nervous system. Classically, this manifests as dilated proximal bowel and constricted distal bowel with absent ganglia and hypertrophic nerve trunks. When recognized early, medical and surgical therapies can be instituted to minimize associated morbidity and mortality. This article reviews current understanding of the etiology of HSCR, its multigenic associations, the historical evolution of HSCR diagnosis and treatment, and current HSCR therapies.

Hirschsprung-associated enterocolitis: prevention and therapy

Hirschsprung-associated enterocolitis remains the greatest cause of morbidity and mortality in children with Hirschsprung disease. This chapter details the various approaches used to treat and prevent this disease process. This includes prevention of complications, such as stricture formation, prophylaxis with rectal washouts, and identification of high-risk individuals. The chapter also details approaches to diagnose Hirschsprung-associated enterocolitis as well as to exclude other etiologies.