Controversies concerning diagnostic guidelines for anomalies of the enteric nervous system: a report from the fourth International Symposium on Hirschsprung's disease and related neurocristopathies

Enough is enough: how many rectal suction biopsies do you need to diagnose Hirschsprung's disease?

PURPOSE

Rectal suction biopsy (RSB) is the gold standard for diagnosing Hirschsprung's disease (HD) in infants. Despite being a common procedure, no standard exists on the number of biopsy specimens and their respective level within the rectum.

METHODS

We conducted a retrospective review of epidemiological and pathological data of patients who underwent RSB at our institution between January 2011 and May 2022. During RSB we obtain 4 specimens: at 1 cm, 3 cm and 5 cm above the dentate line, besides one specimen at the dentate line. We used a logistic regression model for statistical analysis and included control variables (e.g. underlying disease, weight at first biopsy, gestational age).

RESULTS

A total of 92 patients underwent 115 biopsies, with an average of 3.77 specimens per session. Of the specimens taken at 1 cm above the dentate line 73.9% were conclusive, at 3 cm 75.9% and at 5 cm 79.2%. Specimens taken at the dentate line were squamous or transitional epithelia in 31.5% and therefore of no use for HD diagnostics. The specimen at 3 cm shows the highest discriminative power whether the biopsy session was diagnostic (p-value < 1%).

CONCLUSIONS

We propose that a total of three specimens, namely one at 1 cm, one at 3 cm and one at 5 cm above the dentate line, is enough to diagnose or exclude HD.

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.

Historical Cohort Study of Congenital Isolated Hypoganglionosis of the Intestine: Determining the Best Surgical Interventions

No standard diagnostic method or surgical treatment for congenital isolated hypoganglionosis (CIHG) has been established. This study aimed to analyze the clinical outcomes of patients with CIHG and identify the best surgical interventions provided thus far. Data on surgical interventions in 19 patients were collected between 1992 and 2020, including the type of enterostomy, type of revision, and length of the intestines. Ganglion cells in the myenteric plexus were enumerated using Hu C/D staining. The ratio of the length of the small intestine to its height was defined as the intestinal ratio (IR). The outcomes were assessed using the stoma output, growth parameters including the body mass index (BMI), and parenteral nutrition (PN) dependency. All patients required a diverting enterostomy. The IR ranged from 0.51 to 1.75 after multiple non-transplant surgeries. The stoma types were tube-stoma, end-stoma, Santulli-type, and Bishop-Koop (BK)-type. Patients with Santulli- or BK-type stomas had better BMIs and less PN dependency in terms of volume than those with end-stomas or tube-stomas. Two patients with BK-type stomas were off PN, and three who underwent an intestinal transplantation (Itx) achieved enteral autonomy. The management of CIHG involves a precise diagnosis using Hu C/D staining, neonatal enterostomy, and stoma revision using the adjusted IR and Itx if other treatments do not enable enteral autonomy.

Systematic orientation of fresh rectal suction biopsies improves histopathological diagnostics in hirschsprung's disease - a method description and preliminary report

BACKGROUND

Optimizing rectal suction biopsy (RSB) diagnostics in Hirschsprung's disease (HD) may shorten diagnostic time and prevent need for repeated biopsies.

AIM

To explore whether systematic orientation of fresh RSB specimens increased biopsy quality, diagnostic times, diagnostic efficacy, and histopathologic workload, and to explore these outcome measures for aganglionic specimens.

MATERIALS/METHODS

This was an observational case-control study conducted at a national referral center for HD on data collected from the local HD-diagnostic register. From 2019 each fresh RSB was oriented by the collector in a notch in a foam cushion, placed in a separate cassette, and sent in formalin for pathological analysis. Outcome measures of oriented RSB samples collected 2019-2021 were compared to those of non-oriented RSB samples collected 2015-2018. Staining/immunohistochemistry consisted of hematoxylin eosin, S-100 and calretinin.

RESULTS

78 children with 81 RSBs and 242 biopsy analyzes were included. The frequency of high-quality RSB specimens was higher in oriented: 40% (42/106) versus non-oriented 25% (34/136) (p = 0.018), the diagnostic turnaround time was shorter: 2 days (1-5) versus 3 days (2-8) (p = 0.015), and the number of additional sectioning/leveling/re-orientation per biopsy was lower: 7 (3-26) versus 16 (7-72) (p = 0.011). Specifically for aganglionic specimens, the frequency of high-quality biopsies was generally higher in oriented than in non-oriented RSB specimens: 47% (28/59) versus 14% (7/50) (p < 0.001); the diagnostic efficacy was higher 95% (19/20) versus 60% (9/15) (p = 0.027) and the diagnostic turnaround time shorter: 2 days (2-3) versus 3 days (2-8) (p = 0.036).

CONCLUSIONS

Systematic orientation of fresh RSB specimens improves HD diagnostics. Improvement was consistent in aganglionic specimens.

Association between Clinical and Histopathological Findings in Intestinal Neuronal Dysplasia Type B: An Advance towards Its Definition as a Disease

INTRODUCTION

Intestinal neuronal dysplasia type B (IND-B) is a controversial entity that affects the submucosal nerve plexus of the distal intestine. The lack of definition of the causal relationship between histological findings and clinical symptoms has been identified as the primary point to be elucidated in the scientific investigation related to IND-B, which is essential for it to be considered a disease.

OBJECTIVE

To investigate the relationship between histopathological findings and symptoms in a series of patients with IND-B.

METHODS

Twenty-seven patients with histopathological diagnosis of IND-B, according to the Frankfurt Consensus (1990), who underwent surgical treatment through colorectal resections were included. Data from medical records regarding the clinical picture of the patients at the time of diagnosis, including the intestinal symptom index (ISI) and a detailed histopathological analysis of the rectal specimens, were retrieved. Exploratory factor analysis was performed, applying the principal components method for clusters with Varimax rotation.

RESULTS

Two factors were determined: the first, determined by histopathological and clinical variables, and the second, composed of the main symptoms presented in patients with IND-B, including ISI. Factorial rotation showed the association between the two factors and, through a graph, demonstrated the proximity between ISI values and histopathological alterations.

CONCLUSION

There was evidence of an association between the clinical features presented by patients with IND-B and the histopathological findings of the rectal samples. These results support the understanding of IND-B as a disease.

Design of a Pediatric Rectal Ultrasound Probe Intended for Ultra-High Frequency Ultrasound Diagnostics

It has been shown that ultra-high frequency (UHF) ultrasound applied to the external bowel wall can delineate the histo-anatomic layers in detail and distinguish normal bowel from aganglionosis. This would potentially reduce or lessen the need for biopsies that are currently mandatory for the diagnosis of Hirschsprung's disease. However, to our knowledge, no suitable rectal probes for such a use are on the market. The aim was to define the specifications of an UHF transrectal ultrasound probe (50 MHz center frequency) suitable for use in infants. Probe requirements according to patient anatomy, clinicians' requests, and biomedical engineering UHF prerequisites were collected within an expert group. Suitable probes on the market and in clinical use were reviewed. The requirements were transferred into the sketching of potential UHF ultrasound transrectal probes followed by their 3D prototype printing. Two prototypes were created and tested by five pediatric surgeons. The larger and straight 8 mm head and shaft probe was preferred as it facilitated stability, ease of anal insertion, and possible UHF technique including 128 piezoelectric elements in a linear array. We hereby present the procedure and considerations behind the development of a proposed new UHF transrectal pediatric probe. Such a device can open new possibilities for the diagnostics of pediatric anorectal conditions.

Interstitial cells of Cajal: clinical relevance in pediatric gastrointestinal motility disorders

Interstitial cells of Cajal (ICCs) are pacemaker cells of gastrointestinal motility that generate and transmit electrical slow waves to smooth muscle cells in the gut wall, thus inducing phasic contractions and coordinated peristalsis. Traditionally, tyrosine-protein kinase Kit (c-kit), also known as CD117 or mast/stem cell growth factor receptor, has been used as the primary marker of ICCs in pathology specimens. More recently, the Ca2+-activated chloride channel, anoctamin-1, has been introduced as a more specific marker of ICCs. Over the years, various gastrointestinal motility disorders have been described in infants and young children in which symptoms of functional bowel obstruction arise from ICC-related neuromuscular dysfunction of the colon and rectum. The current article provides a comprehensive overview of the embryonic origin, distribution, and functions of ICCs, while also illustrating the absence or deficiency of ICCs in pediatric patients with Hirschsprung disease intestinal neuronal dysplasia, isolated hypoganglionosis, internal anal sphincter achalasia, and congenital smooth muscle cell disorders such as megacystis microcolon intestinal hypoperistalsis syndrome.

The prevalence and clinical presentation of Hirschsprung's disease in preterm infants: a systematic review and meta-analysis

PURPOSE

Hirschsprung's disease (HD) is a rare occurrence in premature infants, and the exact prevalence varying across studies. Thus, we conducted this study to determine the prevalence of and clinical presentation of HD in preterm infants.

METHODS

The PubMed, EmBase, and Cochrane library databases were searched for eligible studies throughout May 2021. The pooled incidence with 95% confidence interval (CI) was calculated using the random-effects model.

RESULTS

Thirty studies involved 4,557 children with HD were included. The pooled proportion of HD patients who were preterm infants was 7% (95% CI 5-8%; P < 0.001); the sensitivity analysis indicated that the pooled prevalence of preterm infants with HD ranged from 5.0% to 5.6%. Moreover, the pooled incidence of abdominal distention in HD patients was 83% (P < 0.001), that of vomiting was 61% (P < 0.001), that of bilious vomiting was 54% (P < 0.001), that of delayed meconium passage was 48% (P < 0.001), that of constipation was 44% (P < 0.001), and that of enterocolitis was 13% (P < 0.001).

CONCLUSIONS

This study reported the prevalence of HD patients who were preterm infants, and the most common presentations were abdominal distention, vomiting, bilious vomiting, delayed meconium passage, constipation, and enterocolitis.

Diagnostic Efficacy of Rectal Suction Biopsy with Regard to Weight in Children Investigated for Hirschsprung’s Disease

Background/aim: Diagnostic efficacy, defined as the percentage of rectal suction biopsy (RSB) specimens sufficient enough to determine the absence of ganglia cells in Hirschsprung’s disease (HD) diagnosis, has been reported to be low, requiring repeated biopsies. The aim was to explore whether RSB diagnostic efficacy was influenced by the child’s weight and to ascertain whether RSB efficacy differed between aganglionic and ganglionic tissue. Materials and Methods: Efficacy analyses were conducted in a national HD-center’s register on children 0–15 kg, examined between 2011–2019. First-time RSB diagnostic efficacy was correlated to the children’s weight and final HD diagnosis. Results: Among the 84 children who had first-time RSB, the overall diagnostic efficacy was 85% (71/84). The efficacy was higher among children weighing less than the identified cut-off of 9.0 kg (89% in 0–9.0 kg versus 62% in 9.01–15.0 kg, p = 0.026). Among children diagnosed with HD, 96% (26/27) weighed 0–9.0 kg. In this weight group, the diagnostic efficacy was lower in aganglionosis compared to ganglionosis (77%; 20/26 versus 96%; 43/45), p = 0.045). Conclusions: The RSB diagnostic efficacy was significantly higher in children weighing less than 9.0 kg and was less in aganglionic compared to ganglionic tissue. Therefore, weight can be useful to predict RSB diagnostic efficacy.

Challenges in the diagnosis of intestinal neuronal dysplasia type B: A look beyond the number of ganglion cells

Intestinal neuronal dysplasia type B (IND-B) is a controversial condition among gastrointestinal neuromuscular disorders. Constipation is its most common clinical manifestation in patients. Despite intense scientific research, there are still knowledge gaps regarding the diagnostic criteria for IND-B in the histopathological analysis of rectal biopsies. The guidelines published in the past three decades have directed diagnostic criteria for quantifying the number of ganglion cells in the nervous plexus of the enteric nervous system. However, it is very complex to distinguish numerically what is pathological from what is normal, mainly because of the difficulty in determining a reliable control group composed of healthy children without intestinal symptoms. Thus, a series of immunohistochemical markers have been proposed to assist in the histopathological analysis of the enteric nervous system. Several of these markers facilitate the identification of other structures of the enteric nervous system, in addition to ganglion cells. These structures may be related to the etiopathogenesis of IND-B and represent new possibilities for the histopathological diagnosis of this disease, providing a view beyond the number of ganglion cells. This review critically discusses the aspects related to the disease definitions and diagnostic criteria of this organic cause of constipation.

Reevaluation of concurrent acetylcholinesterase and hematoxylin and eosin staining for Hirschsprung's disease

BACKGROUND

Acetylcholinesterase (AChE) histochemistry has been widely performed for the histopathological diagnosis of Hirschsprung's disease (HD). However, we occasionally come across diagnostic difficulties. We conducted concurrent AChE histochemistry and hematoxylin and eosin (HE) staining to validate the ancillary value of this technique.

METHODS

Of 177 patients diagnosed using AChE histochemistry from January 2014 to December 2016, 90 patients underwent formalin-fixed paraffin-embedded HE staining. The histopathological findings and diagnostic abilities were investigated and compared retrospectively.

RESULTS

The sensitivity, specificity, accuracy, and kappa index of AChE histochemistry and HE staining were 94.1%, 100%, 98.9%, and 0.964 and 76.5%, 84.9%, 83.3%, and 0.530, respectively. The specificity, accuracy and kappa index of AChE histochemistry were significantly higher than those of HE staining (P < 0.001, <0.001, and <0.05). Hematoxylin and eosin staining supported the suspected diagnosis of total colon aganglionosis at the initial biopsy; furthermore, HE staining helped confirm the distinct shape of ganglion cells and hypertrophic nerve bundles.

CONCLUSION

We re-confirmed that AChE histochemistry is an excellent method for diagnosing HD. Although the diagnostic ability of HE staining is limited, it has acceptable utility as an ancillary method. Thus, AChE staining is a useful test and it should be performed together with HE staining.

Endoscopic Decompression with a Transanal Drainage Tube for the Treatment of Hirschsprung's Disease in Newborns

Background: To evaluate the effectiveness and safety of endoscopic decompression with a transanal drainage tube (ED-TDT) in the treatment of neonatal Hirschsprung's disease (HD). Materials and Methods: Six newborns (4 boys and 2 girls; age at operation 9-29 days, median 24 days) were admitted to our hospital due to the delayed passage of meconium after birth, abdominal distension, and vomiting. HD was diagnosed by the retrograde enema radiography. All patients underwent ED-TDT for decompression of the dilated colon. During the operation, an endoscope was inserted through the anus to the ascending colon or ileocecal region, which was then used to insert a guidewire to the ascending colon. The endoscope was then removed, and a colorectal drainage tube was introduced over the guidewire. This drainage was placed until a pull-through procedure was performed. Results: The ED-TDT was successfully performed in all newborns. The intraoperative rectal biopsy confirmed the diagnosis of HD. The duration of the operation was 25-70 minutes (median 52.5 minutes). There were no perforations, bleeding, or other complications after surgery. After surgery, the abdominal distention was significantly relieved, and the babies could be fed with milk after 6 hours. These babies were discharged after 2-11 days (median 2.5 days) and underwent a pull-through procedure after 1-3 months (median 3 months). Conclusions: ED-TDT is a safe and effective treatment for neonatal HD before a pull-through procedure. It could be used as an alternative therapy to colostomy.

Hirschsprung's Disease Complicated by Sigmoid Volvulus: A Systematic Review

BACKGROUND

Hirschsprung's disease and sigmoid volvulus can sometimes be seen in the same patient.

AIMS

To investigate the presence of Hirschsprung's disease in patients with sigmoid volvulus and to discuss the diagnosis and treatment methods.

STUDY DESIGN

Systematic review.

METHODS

This systematic review has been reported in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the methodological quality of systematic reviews guidelines. The PubMed and Scopus databases were scanned using the keywords "Hirschsprung* volvulus*" and "congenital aganglionic megacolon volvulus*". The reference list of the selected studies was reviewed for cross-checking. Two reviewers independently screened the available literature. Only the Hirschsprung's disease cases involving sigmoid volvulus were included, and cases of patients with volvulus in other sites was excluded. There was no restriction with respect to the publication language and type of writing. The primary outcome was morbidity and mortality.

RESULTS

A total of 31 cases were analyzed in 22 articles; 97% of the patients were under the age of 40, 90% were male. There was a statistically significant difference in the necessity for relaparotomy between patients who were scheduled for sigmoid volvulus therapy with the suspicion of Hirschsprung's disease and patients who were treated without suspicion of Hirschsprung's disease (0% vs 37.5%, p=0.02). While there was no postoperative death in cases with suspected Hirschsprung disease, this mortality rate was 25% in cases without suspicion (p = 0.08).

CONCLUSION

Hirschsprung's disease should be excluded with rectal biopsy if a patient with sigmoid volvulus is under 40 years of age and has complaints of constipation from childhood.

Contemporary management of Hirschsprung disease in New Zealand

BACKGROUND

The aim of this study was to report the contemporary management of Hirschsprung disease (HD) in New Zealand.

METHODS

We undertook a national multi-centre retrospective review of all newly diagnosed cases of HD during a 16-year period (2000-2015). Demographics, genetic and syndromic associations, family history, radiology and histology results and surgical interventions were analysed.

RESULTS

A total of 246 cases (males:females 4:1) were identified, an incidence of 1:3870 live births. Short-segment disease was present in 81.7%, long-segment disease in 8.5%, total colonic aganglionosis in 6.5% and unknown in 3.3%. HD was diagnosed by 4 weeks' corrected gestational age in 67%. Thirty cases (12%) also had Trisomy 21. Fifty-three (21.5%) patients required a repeat rectal biopsy for definitive diagnosis. A contrast enema was performed in 55% and identified the transition zone with 69% accuracy. Primary pull-through surgery was undertaken in 59% (65% of short-segment cases) at a median age of 27 days; others were initially managed by a defunctioning stoma. The commonest definitive procedure was a Soave-Boley endorectal pull-through (79%) (or similar variant). During a median follow-up of 7.4 years, six (2.5%) survivors underwent a redo pull-through, 13 (5.5%) an appendicostomy, 16 (6.8%) a defunctioning stoma and 10 never had a definitive procedure. Total colonic aganglionosis was significantly more likely to be fatal (12.5% versus 0.5%, P < 0.0005) or associated with a permanent end stoma (27.5% versus 4.5%, P < 0.0005).

CONCLUSIONS

Most New Zealand born infants with short-segment HD are currently managed by primary pull-through, usually in the first months of life.

How to use perianal examination in children

No examination of a child's abdomen or gastrointestinal system is complete without an examination of the 'backside' or perineum, however there is often reluctance among paediatricians to perform this examination routinely. This article aims to describe how to use perineal examination in infants and children. It discusses the indications and stepwise approach to performing a per-rectal examination and interpretation of the findings one could expect to encounter. We include four cases encompassing the major conditions, both congenital and acquired, that paediatricians should be aware of and how they were managed in our institution.

Immunohistochemistry-based comparative study in detection of Hirschsprung's disease in infants in a Tertiary Care Center

BACKGROUND:

Hirschsprung's disease (HD) is the major cause of pediatric intestinal obstruction with a complex pattern of inheritance. The absence of ganglion cells along with an analysis of hypertrophy and hyperplasia of nerves in the nerve plexus of submucosa and muscularis mucosae is regarded as a potential hallmark for its diagnosis.

AIMS AND OBJECTIVES:

This study was undertaken to ascertain the (1) clinical profile, (2) mode of presentation, and (3) to compare the role of calretinin immunostaining with acetylcholinesterase in the diagnosis of HD.

MATERIALS AND METHODS:

This prospective and observational study was conducted in the Department of Pathology, IPGME & R from June 2014 to May 2015. One hundred and four patients clinically and radiologically diagnosed with HD underwent surgery were included in the study. The data of every patient including age, sex, and presenting symptoms were recorded. Eventually, histopathological, calretinin, and acetylcholinesterase immunohistochemical examination were done.

RESULTS:

Total numbers of cases studied were 104, which aged between 0 days and 365 days. Male preponderance (76.92%) was noted. The overall sensitivity, specificity, positive, and negative predictive value of acetylcholinesterase were 100%, 86.44%, 84.91%, and 100%, respectively. The concordance of detection of ganglion cells and nerve fibers, and thereby diagnosis of Hirschsprung's and non-HD using calretinin and the gold standard was statistically in strong agreement (κ = 0.749, 95% confidence interval: 0.635–0.863).

CONCLUSIONS:

Calretinin stands out as the single and indispensable tool that differentiates HD from other mimickers.

Mucosectomy disrupting the enteric nervous system causes contraction and shrinkage of gastrointestinal flaps: potential implications for augmentation cystoplasty

INTRODUCTION

Augmenting the bladder with a seromuscular gastrointestinal flap is a promising alternative approach aiming for a mucus-free bladder augmentation; however, the contraction (shrinkage) of the flaps remains a major concern. Enteric nervous system (ENS) abnormalities cause a failure of relaxation of the intestinal muscle layers in motility disorders such as Hirschsprung's disease and intestinal neuronal dysplasia. In mammals, the submucosal enteric nervous plexus contains nitrergic inhibitory motor neurons responsible for muscle relaxation. The authors hypothesize that mucosectomy disconnects the submucosal nervous plexus from the myenteric plexus resulting in flap shrinkage.

STUDY DESIGN

After ethical approval, mucosectomy was performed on vascularized flaps from the ileum, colon, and stomach in five anesthetized pigs. In Group (I), only the mucosa was scraped off with forceps, creating a sero-musculo-submucosal flap, while in Group (II), the mucosa and submucosa were peeled off as one layer, leaving a seromuscular flap. Isolated and detubularized segments served as control. The width of each flap was measured before and after the mucosectomy. The ENS was assessed by neurofilament immunohistochemistry in conventional sections and by acetylcholinesterase and NADPH-diaphorase enzyme histochemistry in whole-mount preparations.

RESULTS

The stomach contracted to a lesser extent of its original width, 92.82 ± 7.86% in Group (I) and 82.24 ± 6.96% in Group (II). The ileum contracted to 81.68 ± 4.25% in Group (I) and to 72.675 ± 5.36% in Group (II). The shrinkage was most noticeable in the colon: 83.89 ± 15.73% in Group (I) and to 57.13 ± 11.51% in Group (II). One-way equal variance test showed significant difference (P < 0,05) between Group (I) and (II), comparing stomach with ileum and ileum with colon. The histochemistry revealed that the submucosal nervous plexus containing nitrergic inhibitory neurons was disconnected from the myenteric plexus in Group (II) of all specimens.

CONCLUSION

Mucosectomy resulted in significant immediate shrinkage of the flaps. This was more expressed when also the submucosa was peeled off, thus fully disrupting the ENS. The shrinkage affected the stomach the least and the colon the greatest. This phenomenon should be taken into consideration when planning mucus-free bladder augmentation.

Efficacy of Sox10 Promoter Methylation in the Diagnosis of Intestinal Neuronal Dysplasia From the Peripheral Blood

OBJECTIVES

Intestinal neuronal dysplasia (IND) is a common malformation of the enteric nervous system. Diagnosis requires a full-thickness colonic specimen and an experienced pathologist, emphasizing the need for noninvasive analytical methods. Recently, the methylation level of the Sox10 promoter has been found to be critical for enteric nervous system development. However, whether it can be used for diagnostic purposes in IND is unclear.

METHODS

Blood and colon specimens were collected from 32 patients with IND, 60 patients with Hirschsprung disease (HD), and 60 controls. Sox10 promoter methylation in the blood and the Sox10 expression level in the colon were determined, and their correlation was analyzed. The diagnostic efficacy of blood Sox10 promoter methylation was analyzed by receiver operating characteristic curve.

RESULTS

The blood level of Sox10 promoter methylation at the 32nd locus was 100% (90%-100%; 95% confidence interval [CI], 92.29%-96.37%) in control, 90% (80%-90%; 95% CI, 82.84%-87.83%) in HD, and 60% (50%-80%; 95% CI, 57.12%-69.76%) in IND specimens. Sox10 promoter methylation in the peripheral blood was negatively correlated with Sox10 expression in the colon, which was low in control, moderate in HD, and high in IND specimens (r = -0.89). The area under the curve of Sox10 promoter methylation in the diagnosis of IND was 0.94 (95% CI, 0.874-1.000, P = 0.000), with a cutoff value of 85% (sensitivity, 90.6%; specificity, 95.0%). By applying a cutoff value of 65%, promoter methylation was more indicative of IND than HD.

DISCUSSION

The analysis of Sox10 promoter methylation in the peripheral blood can be used as a noninvasive method for IND diagnosis.

Identification of potential molecular pathogenesis mechanisms modulated by microRNAs in patients with Intestinal Neuronal Dysplasia type B

This study proposed to determine global microRNA (miRNA) expression and miRNA-regulated pathways in Intestinal Neuronal Dysplasia type B (IND-B). Fifty patients (0-15 years old) with IND-B were included in the study. Peripheral blood samples were collected from all 50 patients and from 10 healthy asymptomatic children (controls). Rectal biopsies were collected from 29/50 patients; biopsy tissues were needle microdissected to isolate the different intestinal layers, for molecular analysis. Global miRNA expression was determined using TaqMan arrays. Correlation analysis between miRNA expression in plasma and biopsy samples as well as among tissues derived from the distinct intestinal layers was performed. Computational approaches were used for miRNA target prediction/identification of miRNA-regulated genes and enriched pathways biologically relevant to IND-B pathogenesis. miRNAs were statistically significantly deregulated (FC ≥ 2 and p ≤ 0.05) in submucosal and muscular layers: over-expressed (miR-146a and miR-146b) and under-expressed (miR-99a, miR-100, miR-130a, miR-133b, miR-145, miR-365, miR-374-5p, miR-451). Notably, let-7a-5p was highly over-expressed in patient plasma compared to healthy controls (FC = 17.4). In addition, miR-451 was significantly under-expressed in both plasma and all biopsy tissues from the same patients. Enriched pathways (p < 0.01) were axon guidance, nerve growth factor signalling, NCAM signalling for neurite out-growth, neuronal system and apoptosis. miRNA expression is deregulated in the submucosa and muscular layers of the rectum and detected in plasma from patients with IND-B. Biologically enriched pathways regulated by the identified miRNAs may play a role in IND-B disease pathogenesis, due to the activity related to the neurons of the enteric nervous system.

Acquired isolated hypoganglionosis as a distinct entity: results from a nationwide survey

PURPOSE

Acquired isolated hypoganglionosis (A-IH) is a late-onset intestinal pseudo-obstruction disorder and shows different pathophysiological findings from congenital isolated hypoganglionosis (C-IH). In this study, we retrospectively examined five cases of A-IH and investigated the features of A-IH.

METHODS

Five cases of A-IH were extracted from a nationwide retrospective cohort study in 10 years, from which totally 355 cases of Allied Disorders of Hirschsprung's Disease (ADHD) were collected.

RESULTS

Ages of onset were between 13 and 17 years in three cases, and 4 years and 4 months in ones. Initial symptoms were abdominal distension and/or chronic constipation in 4 cases, whereas one exhibited intestinal perforation. Affected lesions varied from case to case, extending various length of intestinal tracts. All cases underwent multiple operations (average: 4.6 times), such as enterostomy, resection of dilated intestines, and/or pull-through. Pathological findings showed the decreased numbers of ganglion cells and degeneration of ganglion cells, whereas the size of the plexus was normal. Currently, all cases were alive and almost all eat regular food without requiring parenteral feeding.

CONCLUSION

A-IH is rare, but distinct entity characterized by different clinical courses and pathological findings from those of C-IH. The outcome is considered to be favorable after a resection of affected intestine.

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.

Laparoscopic Redo Pull-Through for Hirschsprung Disease Due to Innervation Disorders

BACKGROUND

Reoperations in Hirschsprung disease (HD) may be required due to pathological problems. We conducted this retrospective study to determine the incidence and outcomes of innervation disorders among HD patients following pull-through operation.

MATERIALS AND METHODS

We retrospectively reviewed the data of patients who underwent pull-through procedure from 2005 to 2017. Only patients who underwent reoperation due to histological disorders were analyzed. Patients with mechanical obstruction that caused recurrent constipation were excluded.

RESULTS

There were 836 patients who got treated for HD in our department during the study period, and of these, 72 (8.6%) had redo operation. Thirty-one out of the 72 patients (43.1%) showed abnormal histological findings on full-thickness biopsies. Primary operations included totally transanal endorectal pull-through (18), laparoscopic-assisted Duhamel (5) and Soave (8) techniques. The full-thickness biopsies before the reoperation showed aganglionosis (n = 8, 1 was residual resulted from false-positive intraoperative frozen sections and 7 were acquired aganglionosis), transition-zone (3), intestinal neuronal dysplasia B (IND B, n = 15), and hypoganglionosis (5). The final diagnoses according to the resection specimens of the initial and second operations were HD (11), Hirschsprung-associated IND B (15), and Hirschsprung-associated hypoganglionosis (5). Reoperation consisted of laparoscopic-assisted Duhamel (14) and Soave procedures (17). In these patients, 77.4% had excellent/good bowel function, 16.1% were fair, and 6.5% were poor.

CONCLUSIONS

Innervation disorders are still the underlying causes of recurrent constipation in almost half of all HD patients requiring redo pull-through operation. Most patients have a satisfactory outcome after redoing laparoscopic-assisted Duhamel or Soave operation.

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.

Air test as a simple method of screening for Hirschsprung's disease

AIM

To present the technique and the diagnostic accuracy of the air test to diagnose Hirschsprung's disease (HD).

MATERIALS AND METHODS

Children who attended hospital for chronic constipation (CC) between January 2012 and December 2016 for whom the air test was performed were enrolled. The test was conducted during contrast enema under fluoroscopic observation using 20-50 ml injections of air into the rectum through a 10 F Nelaton catheter. The demographics, results of the air test, and additional examinations, as well as the outcomes of subsequent treatments were analysed retrospectively.

RESULTS

The air test was conducted in 179 patients (median: 3 years, range: 0-14 years), and was positive in 150 and negative in 29 cases. Of the 29 patients with negative results, four were diagnosed with HD by rectal suction biopsy (RSB). Of the remaining 25 patients, RSB was conducted in seven and HD was excluded in all cases. In all 150 patients with positive air test results, CC was adequately controlled with conservative treatment. The sensitivity and specificity of the air test were 100% (4/4) and 85.7% (150/175), respectively.

CONCLUSIONS

The air test can be used as a new non-invasive screening method for HD, performed simultaneously with contrast enema.

Causes and prognosis of chronic intestinal pseudo-obstruction in 48 subjects: A 10-year retrospective case series

The aim of the study was to evaluate the prognosis and survival of pediatric subjects with chronic intestinal pseudo-obstruction (CIPO) and investigate the independent risk factors affecting their prognosis.This was a retrospective case series of all pediatric subjects suffering from CIPO and treated at the Pediatric Surgical ward of Xinhua Hospital between January 2006 and January 2016.The overall mortality was 19/48 (39.6%). Because of delayed CIPO diagnosis, many subjects underwent a variety of surgical procedures. The rate of additional surgical procedures was high (35/48, 72.9%), but the number of surgical procedures, parenteral nutrition, and megacystis did not affect mortality. Mycotic infection was significantly associated with mortality, while onset at <1 year and hypoganglionosis showed a tendency to be associated with mortality.Mycotic infection was associated with mortality of children with CIPO. Despite improving treatment approaches, the overall prognosis of CIPO remains poor. The choice of the surgical intervention could be based on standard criteria.

Significance of neurexin and neuroligin polymorphisms in regulating risk of Hirschsprung's disease

By performing a basic case-control study among a Chinese population, the aims of this study were to explore if single nucleotide polymorphisms (SNPs) within neurexin and neuroligin were associated with susceptibility to Hirschsprung's disease (HD). Eleven SNPs within neurexin and neuroligin were selected in this basic case-control study, and this study recruited 210 children with HD and 187 healthy children. The t-test and Χ² test were used to find the difference between case and control in their clinical variables. OR and 95% CI were used to assess the association between HD susceptibility and neurexin/neuroligin polymorphisms/haplotypes. Several SNPs were significantly associated with altered risk of HD in the Chinese Han population, including rs1421589 within NRXN1, rs11795613 and rs4844285 within NLGN3, as well as rs5961397, rs7157669 and rs724373 within NLGX4X (all P<0.05). Further studies presented that the effects of rs1421589 within NRXN1, rs4844285 and rs11795613 within NLGN3, as well as rs5961397 within NLGX4X on HD phenotypes were also statistically significant (all P<0.05). Conclusively, the polymorphisms and haplotypes situated within neurexin and neuroligin were markedly associated with the onset of HD, implying that mutations of neurexin and neuroligin might serve as the treatment target for HD for the Chinese children.

Diagnostic Accuracy of Combined Acetylcholinesterase Histochemistry and Calretinin Immunohistochemistry of Rectal Biopsy Specimens in Hirschsprung's Disease

BACKGROUND

Acetylcholinesterase (AchE) histochemistry has been established as an accurate diagnostic tool for Hirschsprung's disease (HD). In addition, calretinin immunohistochemistry is also reported as a reliable and adjunctive method to diagnose HD. We investigated the diagnostic value of combined AchE histochemistry and calretinin immunohistochemistry in rectal suction biopsies from HD and non-HD patients.

METHODS

We retrospectively reviewed 99 rectal suction biopsy specimens including 4 repeat biopsies from 95 patients (34 HD and 61 non-HD). Each specimen was evaluated with hematoxylin-eosin, AchE histochemistry, and calretinin immunohistochemistry.

RESULTS

Of 95 patients, only 21 (22.1%) showed some ganglion cells. All 61 non-HD cases revealed no abnormal AchE-positive fibers. Of 34 HD patients, 32 exhibited abnormal AchE fibers, but 2 showed no stained fibers. None of the tissues from the HD patients exhibited calretinin immunoreactivity. Test sensitivity and specificity of AchE histochemistry alone were 93.5% and 100.0%, respectively, while calretinin immunohistochemistry were 100.0% and 85.2%, respectively.

CONCLUSIONS

AchE histochemistry is a good diagnostic method for HD, if feasible, and a combination of AchE histochemistry and calretinin immunohistochemistry will help increase the accuracy of the diagnosis of HD.

Diagnostic Criteria of Pediatric Intestinal Myopathies

The authors aim to identify criteria for the diagnosis of intestinal visceral myopathy (IVM); results were compared with ultrastructural studies. Six IVM patients and 7 pediatric control cases (without gastrointestinal diseases) were studied. One case was a typical megacystis-microcolon-intestinal hypoperistalsis syndrome. The diagnostic path included: rectal suction biopsy, one-trocar transumbilical laparoscopic intestinal full-thickness biopsy technique. Pathological analysis included anti-alpha smooth muscle actin staining, and US study of intestinal biopsies. IVM histological examination demonstrated thinning of longitudinal muscle layer. The ratio of circular/longitudinal thickness was evaluated in all samples; in cases, this ratio presented as a mean value of 2.91, and in controls, a mean value of 1.472 (P = 0.0002). Ultrastructural diagnosis revealed variable myofibrils density in smooth muscle cells, irregularity of sarcolemma membranes, interstitial fibrosis, and myofiber disarray. The authors concluded that in IVM, circular/longitudinal thickness ratio and alpha smooth muscle actin staining can be used as significant tools to address the diagnosis.

Diagnostic value of the preoperatively detected radiological transition zone in Hirschsprung's disease

BACKGROUND AND OBJECTIVE

The cardinal diagnostic sign of congenital aganglionic megacolon, or Hirschsprung's disease (HD), is an aganglionic segment of the distal colon or rectum. To determine the surgical planning of a radiological transition zone (TZ) in HD, this study investigated the association between a radiological TZ and the bowel resection length.

METHODS

A prospective observational study was conducted in children (n = 192) with suspected HD determined by radiological TZ on contrast barium enema, and who underwent pull-through operations. The bowel resection length was ≥10 cm above the proximal radiological TZ levels and confirmed by intraoperative frozen sections. In the contrast enema, the presence and level of a radiological TZ were recorded. Correlation of the TZ features with ganglion cells assessed by immunostaining of neuronal nuclei (NeuN) and the odds ratio were calculated.

RESULTS

The sensitivity and specificity for diagnosing HD by the presence of a radiological TZ were 86.9 and 92.1%, respectively; Youden's index was 79.0%. The positive and negative predictive values were 91.7 and 87.6%. The kappa value indicating an association between TZ and HD was 0.776 (P < 0.05). The correlation rate between a radiological TZ and the pathological results was 88.5% in the rectosigmoid colon and 44.4% in the descending colon, and was higher in children older than 3 months (85.3%) than in infants (69.0%).

CONCLUSION

A preoperatively determined radiological TZ has potential value to identify the length of resected bowel in patients with HD, and it also has a high predictive value for diagnosis of HD.

Immunostaining for Hu C/D and CD56 is useful for a definitive histopathological diagnosis of congenital and acquired isolated hypoganglionosis

Isolated hypoganglionosis (IHG) has been proposed as a distinct entity with two subtypes: congenital IHG (CIHG) and acquired IHG (AIHG). However, due to the rarity of the disease and the lack of defining histological criteria, the concept of IHG is not widely accepted. We studied paraffin-embedded intestinal specimens from 79 patients diagnosed with Hirschsprung's disease (HD) (n = 49), CIHG (n = 25), and AIHG (n = 5) collected between January 1996 and December 2015. Histopathological diagnosis of HD, CIHG, and AIHG was confirmed by hematoxylin and eosin staining and immunohistochemical staining using Hu C/D and CD56. We evaluated (immuno)histopathological findings, counted the number of ganglion cells, and measured the size of Auerbach's plexus. Hu C/D labeled neuronal cell bodies, whereas CD56 was detected in all neuronal components. In HD, all ganglion cells in Auerbach's plexus in the normoganglionic segment (NGS) were immunoreactive for Hu C/D, whereas in the aganglionic segment (AGS), these were replaced by CD56-positive extrinsic nerve fibers and bundles. The number of ganglion cells in AIHG and CIHG was significantly lower than in the NGS of HD (p < 0.05). Auerbach's plexus was significantly smaller in CIHG (p < 0.05) but in AIHG equivalent to the NGS in HD. In summary, immunostaining for Hu C/D and CD56 is useful for definitive histopathological diagnosis of IHG.

Advances in understanding functional variations in the Hirschsprung disease spectrum (variant Hirschsprung disease)

Hirschsprung disease (HSCR) is a fairly well understood congenital, genetically based functional obstruction due to the congenital absence of ganglion cells in the distal bowel. However, although over 90% of Hirschsprung cases conform to the normally accepted histological diagnostic criteria, it has become increasingly clear that in addition to HSCR, there is a group of functional disturbances relating to a number of other congenital neurodysplastic conditions causing some degree of gastrointestinal tract malfunction. Although these represent a variety of possibly separate conditions of the enteric nervous system, this spectrum it would appear to be also influenced by similar developmental processes. The term "variant Hirschsprung" is commonly used to describe these conditions, but ganglion cells are mostly present if abnormal in number and distribution. These conditions are a problem group being amongst the most difficult to diagnose and treat with possible practical and legal consequences. The problem appears to be possibly one of definition which has proven difficult in the relative paucity of normal values, especially when correlated to age and gestation. It is the purpose of this paper to review the current position on these conditions and to explore possible shared common pathogenetic and genetic mechanisms. This article explores those conditions where a similar pathogenetic mechanisms to HSCR can be demonstrated (e.g. hypoganglionosis) as well as other neural features, which appear to represent separate conditions possibly linked to certain syndromes.

The evaluation of rectal mucosal punch biopsy in the diagnosis of Hirschsprung's disease: a 30-year experience of 954 patients

PURPOSE

For 30 years, we have consecutively performed rectal mucosal punch biopsy to diagnose Hirschsprung's disease. The aim of this study was to evaluate the safety of our technique.

METHODS

Patients with suspected Hirschsprung's disease who underwent punch biopsy, including our original "K-PUNCH" method using an S-moid forceps and non-specific blood-collecting tube at our department and branch hospital between April 1986 and March 2016 were included in the present study. Our punch biopsy technique is characterized by excellent visibility and a direct grasping sensation. The backgrounds and complications of the patients were retrospectively investigated.

RESULTS

During this period, 954 patients (median age 4 months; range 1 day-73 years) underwent punch biopsy. Although there were no cases of severe complications (i.e., rectal perforation, infection or full-thickness biopsy), one (0.1%) of the 954 cases in the early period showed liver dysfunction and required transfusion due to bleeding. In addition, inappropriate specimens were obtained in 37 patients (3.9%).

CONCLUSION

Punch biopsy including the "K-PUNCH" method is considered safe and feasible and is associated with a low rate of complications and inappropriate specimen harvesting among patients of all ages. Comorbidities, including the potential for hemorrhage, should always be considered.

Intestinal neuronal dysplasia type B: A still little known diagnosis for organic causes of intestinal chronic constipation

Intestinal neuronal dysplasia type B (IND-B) is a controversial entity among the gastrointestinal neuromuscular disorders. It may occur alone or associated with other neuropathies, such as Hirschsprung's disease (HD). Chronic constipation is the most common clinical manifestation of patients. IND-B primarily affects young children and mimics HD, but has its own histopathologic features characterized mainly by hyperplasia of the submucosal nerve plexus. Thus, IND-B should be included in the differential diagnoses of organic causes of constipation. In recent years, an increasing number of cases of IND-B in adults have also been described, some presenting severe constipation since childhood and others with the onset of symptoms at adulthood. Despite the intense scientific research in the last decades, there are still knowledge gaps regarding definition, pathogenesis, diagnostic criteria and therapeutic possibilities for IND-B. However, in medical practice, we continue to encounter patients with severe constipation or intestinal obstruction who undergo to diagnostic investigation for HD and their rectal biopsies present hyperganglionosis in the submucosal nerve plexus and other features, consistent with the diagnosis of IND-B. This review critically discusses aspects related to the disease definitions, pathophysiology and genetics, epidemiology distribution, clinical presentation, diagnostic criteria and therapeutic possibilities of this still little-known organic cause of intestinal chronic constipation.

Current practice patterns of rectal suction biopsy in the diagnostic work-up of Hirschsprung's disease: results from an international survey

PURPOSE

The diagnosis of Hirschsprung's disease (HD) was revolutionized by the introduction of rectal suction biopsy (RSB), allowing specimens to be taken without general anesthesia on the ward or as an out-patient procedure. However, insufficient tissue samples are not uncommon, and subsequently histopathologists often remain reluctant to confirm the presence or absence of enteric ganglion cells merely on the basis of submucosal RSBs. The aim of this study was to evaluate the current usage of RSB in the diagnostic work-up of HD based on an international survey.

METHODS

A 15-item questionnaire was distributed among participants and faculty members at the 21st International Meeting of the Pediatric Colorectal Society.

RESULTS

Eighty-seven pediatric surgeons from 30 countries completed the anonymous survey (response rate 70.2 %), grouped into 68 (78.2 %) staff surgeons and 19 (21.8 %) trainees, with a median work experience of 18 years (range 2-45 years). Of these, 74 (85.1 %) use RSB in the diagnostic work-up of patients with suspected HD, whereas 13 (14.9 %) prefer open full-thickness biopsy under general anesthesia. In total, 47 (63.5 %) respondents perform ≥20 RSBs (range 3-100 RSBs) per year. Five different RSB instruments were reported, the most common ones being rbi2 (65.0 %), Solo-RBT (15.0 %) and multipurpose suction biopsy kit (8.3 %). Only 22 (29.7 %) of the respondents use a defined negative suction pressure, with a median of 10 mL air (range 6-25 mL air). The most proximal reported biopsy site was located at a median of 2 cm (range 1-15 cm) above the pectinate line and a median of 2 (range 1-5) specimens are routinely taken, mainly from the posterior rectal wall. Insufficient tissue samples with need for repeat RSB were encountered in a median of 10 % (range 0-40 %). Most frequently used staining methods for rectal biopsies are hematoxylin/eosin (75.9 %), acetylcholinesterase (73.6 %), and calretinin (33.3 %). Overall, 36 (48.6 %) respondents had experienced RSB-related complications, including self-limiting rectal blood loss (n = 28), persistent rectal bleeding requiring blood transfusion (n = 9) and rectal perforation requiring surgical intervention (n = 7).

CONCLUSIONS

Although RSB is considered to be today's gold standard for the diagnosis of HD, many aspects of its current usage are lacking consensus. Therefore, a prospective multi-center study or larger global audit appears warranted to identify if the present survey reflects common surgical practice and to establish universal standards for RSB.

Rectal biopsy for Hirschsprung's disease: a review of techniques, pathology, and complications

BACKGROUND

Hirschsprung's disease (HD) is one of the most common congenital anomalies of colorectal function, affecting approximately 1 in 5000 live births, with a 4:1 male predominance. HD is characterized by aganglionosis that is most often limited to the rectosigmoid, but can extend proximally along the colon and, in rare instances, reach into the small intestine. A clinical history of delayed passage of meconium beyond 48 hours after birth, physical exam findings of abdominal distention and vomiting, and a contrast enema demonstrating a transition zone are highly suggestive of HD.

DATA SOURCES

We searched databases including PubMed, Google Scholar, and Scopus for the following key words: Hirschsprung's disease, rectal biopsy, pathology, ganglion cell, nerve trunk hypertrophy, pediatric constipation, and selected publications written in English that were relevant to the scope of this review.

RESULTS

Based on the data presented in the literature, we reviewed 1) biopsy techniques for the diagnosis of Hirschsprung's disease, addressed inadequate biopsies, and complications from rectal biopsy, and 2) pathologic and histologic interpretation of biopsy specimens for the diagnosis of Hirschsprung's disease.

CONCLUSION

A well-executed rectal biopsy with expert pathologic evaluation of the specimen remains the gold standard for the diagnosis of Hirschsprung's disease and is the subject of this review.

Rectal suction biopsy for the diagnosis of Hirschsprung's disease: a systematic review of diagnostic accuracy and complications

PURPOSE

Rectal suction biopsy (RSB) combined with acetylcholinesterase (AChE) staining is currently the gold standard for the diagnosis of Hirschsprung's disease (HD). However, some pathologists are still reluctant to diagnose HD in RSBs as it requires thick submucosal tissue to confirm the absence of ganglion cells. Furthermore, insufficient specimens and adverse events have been reported. The objective of this study was to determine the diagnostic accuracy and incidence of complications of RSBs in patients suspected of HD based on a systematic review of the published literature.

METHODS

A literature-based search for relevant publications was conducted using multiple online databases. Staining for AChE/hematoxylin and eosin should have been used to evaluate RSBs. The number of true-positive, false-positive, true-negative and false-negative results was recorded and data on RSB-related complications was extracted. Pooled incidence rates and odds ratios (ORs) with 95% confidence intervals (CI) were calculated using standardized statistical methodology.

RESULTS

Fifty-eight studies met defined inclusion criteria, reporting a total of 14,053 RSBs. The median cohort size consisted of 72 patients (range 1-766) with a median age of 14.4 months (range 1 day-66 years) at time of biopsy. In 89.93% (CI 89.11-90.70%), RSB provided adequate tissue for the diagnosis of HD. Insufficient specimens were obtained in 10.07% (CI 9.30-10.89%) and in 8.46 % (CI 7.55-9.46%) RSB was repeated. The incidence of HD was 19.13% (CI 18.25-20.03%). Mean sensitivity of RSB was 96.84% (CI 95.57-97.47%) and mean specificity was 99.42% (CI 99.17-99.57%). The overall complication rate was 0.65% (CI 0.46-0.91%) with persistent rectal bleeding requiring blood transfusion in 0.53% (CI 0.36-0.77%), bowel perforation in 0.06% (CI 0.02-0.18%) and pelvic sepsis in 0.06% (CI 0.02-0.18%). Complications were significantly more frequent in newborns and infants compared to older children (OR 9.00 [CI 4.75-17.07], p < 0.0001).

CONCLUSIONS

RSB combined with AChE staining is a simple, safe and accurate method for the diagnosis of HD. The risk for RSB-related complications is higher in newborns and infants.

The incidence and outcome of allied disorders of Hirschsprung's disease in Japan: Results from a nationwide survey

BACKGROUND

Allied disorders of Hirschsprung's disease (ADHD) have been proposed to be the concept of the functional obstruction of the intestine with the presence of ganglion cells in the terminal rectum. They are classified into two categories based on pathology: (1) abnormal ganglia, including immaturity of ganglia, hypoganglionosis (HG), and intestinal neuronal dysplasia; (2) normal ganglia, including megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS), segmental dilatation (SD), internal anal sphincter achalasia (IASA), and chronic idiopathic intestinal pseudo-obstruction (CIIP). Some of these show poor prognosis, therefore, the establishment of criteria and appropriate treatment strategies is required.

METHODS

The questionnaires were sent to the 161 major institutes of pediatric surgery or gastroenterology in Japan, in order to collect the cases of ADHD during 10 years from 2001 and 2010.

RESULTS

In total, 355 cases were collected. They included 28 immaturity of ganglia, 130 HG (121 congenital, 9 acquired), 18 intestinal neuronal dysplasia, 33 MMIHS, 43 SD, three IASA, and 100 CIIP. Of the 95 institutes, 69 (72.6%) had their own criteria for ADHD. Criteria were based on clinical symptoms and signs, and conventional pathological examinations. Prognosis was poor in congenital HG, MMIHS, and CIIP, while the others showed good survival rates.

CONCLUSION

Almost all Japanese cases of ADHD in the past 10 years were collected. Congenital HG and CIIP showed relatively high incidence, whereas acquired HG and IASA were extremely rare in Japan. The criteria of each disorder were also collected and summarized. Prognosis was poor in congenital HG, MMIHS, and CIIP.

Reevaluation of acetylcholinesterase staining for the diagnosis of Hirschsprung disease and allied disorders

OBJECTIVES

Acetylcholinesterase (AChE) staining has become the gold standard for definitively diagnosing Hirschsprung disease (HD), although some pitfalls have been reported. We reevaluated a large series at our institute in order to validate the accuracy of AChE staining for detecting HD.

METHODS

A retrospective study of the rectal mucosal specimens of all of the children with suspected HD during a 13-year period was performed. The specimens were stained according to the modified Karnovsky-Roots method for AChE staining. The final diagnosis, prognosis, and management after the histopathological diagnosis were analyzed with a questionnaire sent to the patient's original hospital.

RESULTS

Three hundred and fifty-eight specimens were collected. One hundred twenty-two (34%) specimens were diagnosed as HD, 198 (55%) as nonHD, 25 (7%) as "undetermined," and 13 (4%) as "inappropriate." The non-HD group contained 190 (96%) specimens with a normal appearance and 8 (4%) specimens with suspected intestinal neuronal dysplasia (IND). Three hundred and six of 358 questionnaires were returned. The final diagnosis showed that no specimens first diagnosed as HD were identified as non-HD and vice versa, for a sensitivity and specificity of 100%. Four cases were finally diagnosed as chronic idiopathic intestinal pseudo-obstruction (CIIP) in the non-HD group. All of the patients with HD underwent radical surgery. Most non-HD patients were managed conservatively, although some continued to have constipation.

CONCLUSIONS

AChE staining is an accurate tool for differentiating between HD and non-HD with high sensitivity and specificity. CIIP can be included in cases of non-HD; therefore, careful follow-up is mandatory.

Effects of RET and NRG1 polymorphisms in Indonesian patients with Hirschsprung disease

BACKGROUND

Hirschsprung disease (HSCR) is a neurocristopathy characterized by absence of intramural ganglion cells along variable lengths of the gastrointestinal tract in neonates. Three polymorphisms, rs2435357, within a conserved transcriptional enhancer of RET, and, rs7835688 and rs16879552, within intron 1 of NRG1, have been shown to be associated with isolated forms of HSCR. We wished to replicate these findings, and study the interactions between these variants, in Indonesian HSCR patients.

METHODS

Sixty isolated HSCR patients and 124 controls were ascertained for this study. The three genetic markers were examined using TaqMan Genotyping Assays in genomic DNA for association studies.

RESULTS

RET rs2435357 showed the strongest association with HSCR both by case-control analysis (p=2.5 × 10(-8)) and transmission disequilibrium test (p=4.2 × 10(-6)). NRG1 rs7835688 was modestly associated with HSCR only by case-control analysis (p=4.3 × 10(-3)), whereas rs16879552 demonstrated no association (p>0.097). Two locus analyses of variants showed significant interactions with increased and decreased disease risks of HSCR at NRG1 but conditional on rs2435357 genotype.

CONCLUSIONS

RET and NRG1 variants are common susceptibility factors for HSCR in Indonesia. These common variants demonstrate that development of HSCR requires joint effects of RET and NRG1 early in gut development.

Hirschsprung's Disease and Associated Congenital Heart Defects: A Prospective Observational Study from a Single Institution

OBJECTIVE

To define the prevalence and characteristics of associated congenital heart diseases (CHDs) in patients with Hirschsprung's disease (HSCR).

METHOD

All patients with a histological diagnosis of HSCR admitted to our hospital between January 2010 and December 2013 were included in this prospective observational study and underwent cardiovascular screening. Cardiac anatomy was assessed by a segmental echocardiographic approach. Measurements of aortic root and left ventricular dimensions, wall thickness, and function were obtained. CHDs requiring a percutaneous or surgical intervention were described as major heart diseases.

RESULTS

One hundred thirty-three consecutive patients were enrolled at median age of 2.3 years. Eleven patients (8.3%) presented an associated heart disease. Moreover, five patients had mild dilatation of aortic root. Six out of 11 (4.5%) patients had a major CHDs requiring surgical repair.

CONCLUSION

Prevalence of associated CHDs was slightly higher than in previous papers, and mostly represented by septal defects. Four out of six patients with major heart disease had also a chromosomal anomaly. If we do not consider the subpopulation of patients with a chromosomal anomaly, cardiac defects were present in 3.8% of the patients. Based on these results, we suggest to perform routine echocardiogram in all Hirschsprung patients, with or without associated chromosomal syndromes.

Isolated intestinal neuronal dysplasia Type B (IND-B) in Japan: results from a nationwide survey

PURPOSE

Intestinal neuronal dysplasia Type B (IND-B) has been proposed to be an allied disorder of Hirschsprung's disease (ADHD). The original histological criteria included hyperganglionosis, giant ganglia, ectopic ganglion cells and an increased AChE activity in the lamina propria. The criteria for IND-B have been gradually revised. The present diagnostic criteria are [1] more than 20 % of the submucosal ganglia contain nine or more ganglion cells and [2] the patient is older than 1 year. To clarify the current status of IND-B in Japan, a nationwide retrospective cohort study was performed.

METHODS

Questionnaires were sent to 161 major institutes of pediatric surgery and gastroenterology in Japan.

RESULTS

A total of 355 cases of ADHD were collected, including 18 cases of IND-B (5 %). Based on original criteria, 13 out of 18 cases were diagnosed as IND-B. However, only four cases met the current criteria. Three of the four patients (75 %) required pull-through operation. All of the patients exhibited giant ganglia and ganglioneuromatosis-like hyperplasia of the myenteric plexus.

CONCLUSIONS

IND-B cases matching the current criteria are thought to be quite rare and they are associated with marked hyperplasia of the myenteric plexus. "True" IND-B is a rare and intractable disease.

Calretinin, β-tubulin immunohistochemistry, and submucosal nerve trunks morphology in Hirschsprung disease: possible applications in clinical practice

OBJECTIVES

The aim of this study was to investigate calretinin and β-tubulin immunohistochemical expression together with submucosal nerve trunks morphology in differently innervated segments of Hirschsprung disease (HD) and total colonic aganglionosis (TCA).

METHODS

A total of 25 cases (22 HD, 3 TCA) and 18 controls were processed for calretinin and β-tubulin immunohistochemistry. Sections representative of distal aganglionic, transition, and proximal ganglionic segments were evaluated by a visual grading score; β-tubulin was evaluated also by image analysis. Submucosal nerve trunks hypertrophy and hyperplasia were measured by citomorphology. The length of proximal segment was correlated to postoperative bowel function.

RESULTS

Controls showed intense calretinin and β-tubulin staining. In HD and TCA, calretinin staining was related to the presence of ganglion cells: negative in distal, faint in transition, intense in proximal segment. β-Tubulin staining was weak in all of the segments of HD and negative in TCA. Hypertrophic and hyperplastic nerve trunks characterized aganglionic segment, and progressively decreasing nerve size was observed in transition and ganglionic segments. Transient postoperative constipation, soiling, or enterocolitis was present in 59% of patients with HD without clear relation to proximal segment length or presence of hypertrophic nerve trunks.

CONCLUSIONS

Calretinin is a reliable marker of the presence of ganglion cells, and, together with nerve hypertrophy, it helps to identify the transition zone. Length and nerve size of proximal segment in resected specimen did not affect the postsurgical intestinal function. Reduced β-tubulin expression along the entire colonic tract, included proximal ganglionic segments, may represent a potential impairing factor for the enteric neural transmission.

A prospective observational study of associated anomalies in Hirschsprung's disease

BACKGROUND

Associated anomalies have been reported in around 20% of Hirschsprung patients but many Authors suggested a measure of underestimation. We therefore implemented a prospective observational study on 106 consecutive HSCR patients aimed at defining the percentage of associated anomalies and implementing a personalized and up-to-date diagnostic algorithm.

METHODS

After Institutional Ethical Committee approval, 106 consecutive Hirschsprung patients admitted to our Institution between January 2010 and December 2012 were included. All families were asked to sign a specific Informed Consent form and in case of acceptance each patient underwent an advanced diagnostic algorithm, including renal ultrasound scan (US), cardiologic assessment with cardiac US, cerebral US, audiometry, ENT and ophthalmologic assessments plus further specialist evaluations based on specific clinical features.

RESULTS

Male to female ratio of our series of patients was 3,4:1. Aganglionosis was confined to the rectosigmoid colon (classic forms) in 74,5% of cases. We detected 112 associated anomalies in 61 (57,5%) patients. The percentage did not significantly differ according to gender or length of aganglionosis. Overall, 43,4% of patients complained ophthalmologic issues (mostly refraction anomalies), 9,4% visual impairment, 20,7% congenital anomalies of the kidney and urinary tract, 4,7% congenital heart disease, 4,7% hearing impairment or deafness, 2,3% central nervous system anomalies, 8,5% chromosomal abnormalities or syndromes and 12,3% other associated anomalies.

CONCLUSIONS

Our study confirmed the underestimation of certain associated anomalies in Hirschsprung patients, such as hearing impairment and congenital anomalies of the kidney and urinary tract. Subsequently, based on our results we strongly suggest performing renal US and audiometry in all patients. Conversely, ophthalmologic assessment and cerebral and heart US can be performed according to guidelines applied to the general population or in case of patients with suspected clinical features or chromosomal abnormalities. This updated diagnostic algorithm aims at improving overall outcome thanks to better prognostic expectations, prevention strategies and early rehabilitation modalities. The investigation of genetic background of patients with associated anomalies might be the next step to explore this intriguing multifactorial congenital disease.

A practical guide for the diagnosis of primary enteric nervous system disorders

OBJECTIVE

Primary gastrointestinal neuropathies are a heterogeneous group of enteric nervous system (ENS) disorders that continue to cause difficulties in diagnosis and histological interpretation. Recently, an international working group published guidelines for histological techniques and reporting, along with a classification of gastrointestinal neuromuscular pathology. The aim of this article was to review and summarize the key issues for pediatric gastroenterologists on the diagnostic workup of congenital ENS disorders. In addition, we provide further commentary on the continuing controversies in the field.

RESULTS

Although the diagnostic criteria for Hirschsprung disease are well established, those for other forms of dysganglionosis remain ill-defined. Appropriate tissue sampling, handling, and expert interpretation are crucial to maximize diagnostic accuracy and reduce interobserver variability. The absence of validated age-related normal values for neuronal density, along with the lack of correlation between clinical and histological findings, result in significant diagnostic uncertainties while diagnosing quantitative aberrations such as hypoganglionosis or ultrashort Hirschsprung disease. Intestinal neuronal dysplasia remains a histological description of unclear significance.

CONCLUSIONS

The evaluation of cellular quantitative or qualitative abnormalities of the ENS for clinical diagnosis remains complex. Such analysis should be carried out in laboratories that have the necessary expertise and access to their own validated reference values.

Down-regulation of MeCP2 in Hirschsprung's disease

BACKGROUND/PURPOSE

Hirschsprung's disease (HSCR) is a congenital disorder characterized by the absence of intramural ganglion cells which are highly associated with impaired proliferation and migration of neural crest cells. Whether methyl CpG binding protein 2 (MeCP2) is related with HSCR still remains unknown. This study investigates the involvement of MeCP2 in HSCR.

METHODS

Quantitative real time PCR and western blot were used to detect the expression level of MeCP2 both in the aganglionic/diseased segment and the ganglionic/normal segment. In vitro assays we used siRNAs to knock-down the expression of MeCP2 in SH-SY5Y cell lines, and furthermore, MTT and transwell assays were used to detect the proliferation and migration ability, respectively. In addition, bisulfite sequencing (BSP) and miRNA analysis were used to examine why MeCP2 is decreased in HSCR samples.

RESULTS

MeCP2 exhibited a lower expression level in tissues of HSCR patients compared with the controls. The down-regulation may also suppress the proliferative ability of the cells. However, there was no significant difference in the MeCP2 methylation level between cases and controls. Similarly, there was no difference between cases and controls in miRNA-34b (miR-34b) which is predicted to regulate MeCP2 through complementary binding to the 3'-untranslated region of MeCP2.

CONCLUSION

Our results indicated that an aberrant decreased level of MeCP2 may play an important role in the pathogenesis of HSCR.