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

Loss of α-smooth muscle actin immunostaining is not a useful marker for functional impairment: a comparison from patients with and without small bowel motility disorder

OBJECTIVE

Prior studies have reported the loss of α-smooth muscle actin (α-SMA) immunoreactivity in the inner circular layer of the muscularis propria in small bowel motility disorder cases, but this remains controversial with conflicting data. In this study, we aimed to characterize α-SMA immunoreactivity in the muscularis propria of the small intestine-specifically, jejunum-in patients with and without small bowel motility disorder.

METHODS

A total of 28 transmural proximal jejunum biopsy specimens from adult patients with clinical impression of upper gastrointestinal dysmotility disorder and 64 control tissues were evaluated. The controls were full-thickness, longitudinal tissue sections from segmental resections performed due to gunshot wounds, multivisceral transplant donation, and tumors. Immunostaining for α-SMA was performed with appropriate controls to confirm the presence of immunoreactivity in the circular and longitudinal muscle layers of the muscularis propria in each sample and recorded as retained or diminished.

RESULTS

In the small bowel motility disorder and control cases, 42.9% (12/28) and 70.3% (49/64) of the cases showed no or minimal α-SMA immunoreactivity in the inner circular layer with peripheral accentuation, respectively.

CONCLUSIONS

Loss or diminished α-SMA immunoreactivity in the inner circular layer of the muscularis propria occurs with a similar frequency in cases with and without small bowel motility disorder and does not correlate with impairment of function.

The Diagnostic Value of Immunohistochemistry Markers in Hirschsprung Disease; A Systematic Review and Meta-analysis

BACKGROUND

Immunohistochemistry (IHC) markers are employed to improve the diagnostic yield when testing for Hirschsprung disease (HSCR). Yet, a superior test has not been identified.

OBJECTIVES

We aimed to determine the diagnostic test accuracy (DTA) of IHC markers.

METHODS

We conducted database search for studies reporting IHC staining on rectal biopsy investigating for HSCR. We constructed 2 × 2 contingency tables, and calculated DTA estimates in pooled and paired testing using random-effect model meta-analysis.

RESULTS

Twenty eight IHC markers from 107 studies were used to investigate for HSCR in 10891 children. In pooled analysis; calretinin sensitivity and specificity were superior to acetylcholinesterase, S100, and peripherin [98 % (CI; 0.95-0.99) & 99 % (CI; 0.97-0.99)], [94 % (CI; 0.86-0.97) & 99 % (CI; 0.96-0.99)], [92 % (CI; 0.85-0.96) & 97 % (CI; 0.89-0.99)] and [91.7 % (CI; 0.54-0.98) & 94.8 % (CI; 0.59-0.99)], respectively. In paired analysis calretinin diagnostic odds ratio was superior to hematoxylin and eosin (H&E), acetylcholinesterase and S100: [3349 (PI; 551.3-22667.2) vs 345.3 (PI; 54.9-2394.2)], [300.9 (PI; 13.3-4146.9) vs 34.6 (PI; 2.2-363.9)] and [696.9 (PI; 91.2-3401.7) vs 196.9 (PI; 29.8-890.5)], respectively. In biopsies labelled inadequate for H&E testing, calretinin specificity to rule out HSCR reached 92 % (CI; 0.288-0.998).

CONCLUSIONS

IHC provides additional diagnostic value over H&E. Calretinin appears to be, currently, a superior IHC marker. The available literature is of variable quality, cautious interpretation of the findings should be considered.

LEVEL OF EVIDENCE

III.

Management of Hirschsprung's Disease: A Survey with Brazilian Pediatric Surgeons

BACKGROUND

Hirschsprung's disease (HD) is a congenital malformation of the enteric nervous system clinically manifested by intestinal obstruction in the neonatal period or severe constipation in childhood. Several surveys on HD have been conducted to evaluate experiences in its management around the world. For the first time in Brazil, we analyze and report the management patterns of HD among pediatric surgeons in Brazil.

METHODS

A validated questionnaire was disseminated in print at the Congress of Pediatric Surgery in São Paulo-Brazil, and an online version was sent to all the active members of the Brazilian and Paulista Institute of Pediatric Surgery.

RESULTS

In total, 361 pediatric surgeons answered the survey. Of these, 329 completed all questions (response rate: 91%). Most Brazilian services treat fewer than 10 cases of HD annually. The preferred diagnostic method was rectal biopsy. For newborns (NBs) and infants, open biopsy was the most commonly used technique. For NBs with HD clinically stable 50% of specialists chose immediate surgery. In NBs and infants with classic HD, the Soave technique (69%) is the most common surgical intervention, and the transanal route (80%) is the preferred surgical approach. In children over 3 years of age with classic HD, the most-used technique is the Duhamel method (54%), with the open approach being the most common (52%).

CONCLUSIONS

Our study in Brazil found that HD patient management aligns with scientific evidence and international guidelines.

Gut Analysis Toolbox - automating quantitative analysis of enteric neurons

The enteric nervous system (ENS) consists of an extensive network of neurons and glial cells embedded within the wall of the gastrointestinal (GI) tract. Alterations in neuronal distribution and function are strongly associated with GI dysfunction. Current methods for assessing neuronal distribution suffer from undersampling, partly due to challenges associated with imaging and analyzing large tissue areas, and operator bias due to manual analysis. We present the Gut Analysis Toolbox (GAT), an image analysis tool designed for characterization of enteric neurons and their neurochemical coding using two-dimensional images of GI wholemount preparations. GAT is developed in Fiji, has a user-friendly interface, and offers rapid and accurate segmentation via custom deep learning (DL)-based cell segmentation models developed using StarDist, as well as a ganglia segmentation model in deepImageJ. We apply proximal neighbor-based spatial analysis to reveal differences in cellular distribution across gut regions using a public dataset. In summary, GAT provides an easy-to-use toolbox to streamline routine image analysis tasks in ENS research. GAT enhances throughput, allowing rapid unbiased analysis of larger tissue areas, multiple neuronal markers and numerous samples.

Is It Safe to Operate without Frozen Section Biopsies in Short-Segment Hirschsprung's Disease? An Overview of 60 Cases

Background: Advancements in surgical management in a single-stage procedure made intraoperative frozen section biopsies critical for determining of level of resection to avoid the potential risk of leaving a retained aganglionic segment. However, in most low-income countries, due to the lack of this facility, the surgeon's intraoperative judgment is used for the determination of the resection level. Objective: This study aims to evaluate the accuracy of determining the level of bowel resection in short-segment Hirschsprung's disease based on macroscopic changes. Materials and methods: Intraoperative macroscopic evaluations were assessed using postoperative microscopic findings to determine whether the surgeons' intraoperative judgments were accurate in determining the level of bowel resection in 60 cases of operated short-segment Hirschsprung's disease. In addition, Pearson's correlation coefficient was used to determine whether the sensitivity and specificity of both methods were significantly correlated. Results: The microscopic results showed that the level of resection based on the macroscopic evaluation was performed in normally ganglionated segment in cases of short-segment Hirschsprung's disease. Conclusions: Macroscopic intraoperative assessment by an experienced surgeon is highly accurate method of determining the level of bowel resection in short-segment HSCR.

Diagnostic and therapeutic approach to children with chronic refractory constipation: Consensus report by the SIGENP motility working group

Constipation is a common problem in children, accounting for about 3% of all primary care visits and up to 25% of referrals to paediatric gastroenterologists. Although polyethylene glycol often proves effective, most children require prolonged treatment and about 50% of them have at least one relapse within the first 5 years after initial recovery. When conventional treatment fails, children are considered to have refractory constipation. Children with refractory constipation deserve specialist management and guidance. Over the last decades, there has been a remarkable increase in our knowledge of normal and abnormal colonic and anorectal motility in children, and a number of different techniques to measure transit and motility have been developed. The present review analyses the possible diagnostic investigations for children with refractory constipation, focusing on their actual indications and their utility in clinical practice. Moreover, we have also analytically reviewed medical and surgical therapeutic options, which should be considered in selected patients in order to achieve the best clinical outcome.

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.

Does Length of Extended Resection Beyond Transition Zone Change Clinical Outcome for Hirschsprung Pull-Through?

INTRODUCTION

A proximal resection margin greater than 5 cm from the intra-operative histologically determined transition zone has been deemed necessary to minimize the risk of transition zone pull-through. This extended resection may require the sacrifice of vascular supply and even further bowel resection. The impact of extended proximal resection margin on post-operative complications and functional outcomes is unclear.

METHODS

A retrospective chart review of patients who underwent primary pull-through for Hirschsprung disease at a single institution between January 2008 and December 2022 was performed. An adequate proximal margin was defined by a circumferential normally ganglionated ring and absence of hypertrophic nerves. The extended margin was defined as the total length of proximal colon with normal ganglion cells and without hypertrophic nerves. Fecal incontinence severity was assessed with the Pediatric Fecal Incontinence Severity Score (PFISS).

RESULTS

Eighty seven patients met criteria for inclusion. Median age at primary pull-through was 17 days (IQR 10-92 days), 55% (n = 48) of patients had an extended proximal margin (EPM) ≤ 5 cm, and 45% (n = 39) had an EPM > 5 cm. An EPM ≤5 cm was not associated with increased rates of Hirschsprung associated enterocolitis (≤5 cm 43%, >5 cm 39%, P = 0.701), diversion post pull-through (≤5 cm 10%, >5 cm 5%, P = 0.367) or reoperation for transition zone pull-through (≤5 cm 3%, >5 cm 0%, P = 0.112). EPM ≤5 cm had more frequent involuntary daytime bowel movements (P = 0.041) and more frequent voluntary bowel movements (P = 0.035). There were no differences in other measures of fecal incontinence severity.

CONCLUSIONS

Shorter proximal extended margins beyond the adequate ganglionated margin do not significantly impact post-operative complication rates and have an unclear effect on fecal incontinence.

TYPE OF STUDY

Case Control.

LEVEL OF EVIDENCE

Level III.

The Junction Between the Peristaltic and Non-peristaltic Bowel (Shore Break) is Found in the Transition Zone in Hirschsprung's Disease

BACKGROUND

The junction between the peristaltic and non-peristaltic bowel, which is named the "shore break" (SB), observed on endoscopy is thought to be the boundary between normal and abnormal motility in Hirschsprung's disease (HD). The transition zone (TZ), which is the histopathological border, does not have normal motility and should be resected. This study aimed to evaluate the histopathological findings of the SB and determine the association between the SB and TZ.

METHODS

A retrospective review of surgical specimens of patients with HD who underwent preoperative SB marking was conducted. The TZ was defined if nerve hypertrophy, myenteric hypoganglionosis, or partial circumferential aganglionosis was detected.

RESULTS

Ten patients (9 boys and 1 girl) were studied. The median age at surgery was 30 days. The median distance from the anal verge to the marked SB site was 14 cm. No patients manifested any obstructive symptoms resulting from a residual TZ bowel. In eight patients, nerve hypertrophy was identified at the proximal margin and at the SB. Myenteric hypoganglionosis was identified in three patients at the proximal margin and SB. Partial circumferential aganglionosis was identified at the SB in two patients. As a result, in all patients, the pull-through site and SB site had histopathological features indicating TZ.

CONCLUSIONS

The SB is located in the TZ. Our results suggest that the proximal part of the TZ has normal motility and that functional border points may be present in the TZ.

LEVEL OF EVIDENCE

IV.

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.

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 m6A methyltransferase METTL3 affects cell proliferation and migration by regulating YAP expression in Hirschsprung disease

BACKGROUND

METTL3, an mRNA m⁶A methyltransferase, has been implicated in various steps of mRNA metabolism, such as stabilization, splicing, nuclear transportation, translation, and degradation. However, whether METTL3 dysregulation is involved in Hirschsprung disease (HSCR) development remains unclear. In this study, we preliminarily elucidated the role of METTL3 in HSCR and sought to identify the associated molecular mechanism.

METHODS

The gene expression levels of YAP and several methyltransferases, demethylases, and effectors were evaluated by RT-qPCR. Protein levels were evaluated by western blot and immunohistochemistry. Cell proliferation and migration were detected by CCK-8 and Transwell assays, respectively. The overall levels of m⁶A modification were determined by colorimetry.

RESULTS

We found that m⁶A levels were reduced in the stenotic intestinal tissue of patients with HSCR. When METTL3 was knocked down in SH-SY5Y and HEK-293T cells, the proliferative and migratory abilities of the cells were inhibited, m⁶A modification levels were reduced, and YAP expression was increased. Importantly, YAP and METTL3 expression displayed a negative correlation in both cell lines as well as in HSCR tissue.

CONCLUSIONS

Our results provide evidence for an interaction between METTL3 and YAP in HSCR, and further suggest that METTL3 is involved in the pathogenesis of HSCR by regulating neural crest cell proliferation and migration upstream of YAP.

Sigmoid Volvulus as a Clinical Manifestation of Acquired Colonic Hypoganglionosis: A Case Report

A reduced and limited number of myenteric ganglia and low acetylcholinesterase activity in the lamina propria characterizes an unusual form of intestinal innervation disorder known as acquired or adult-onset hypoganglionosis. Only a few cases have been observed in adults, while the majority are diagnosed in infancy or youth. We report a rare case of colonic hypoganglionosis that presented as sigmoid volvulus in a 25-year-old female brought in to the ER. She underwent endoscopic decompression but developed a massive sigmoid volvulus with proximal colon dilatation. It was decided to do a total colectomy with an end ileostomy. The diagnosis was confirmed by histopathology, which revealed acquired hypoganglionosis. In order to prevent delayed or emergency presentation and the development of a stoma, the diagnosis of hypoganglionosis must be confirmed with full-thickness biopsies from all affected parts of the large bowel. Hypoganglionosis is rarely present, so young patients with a history of chronic constipation must be treated with a high index of suspicion.

Intestinal neuronal dysplasia presenting as psoas abscess: A case report

Background

Intestinal neuronal dysplasia (IND) is a rare condition mainly affecting the children. Constipation and abdominal distension have been reported as common manifestations. In addition, the reports about adult cases are scarce.

Case report

A 31-year-old man presented with pain in his left hip and intermittent fever for 1 month. The whole abdomen CT and pelvic contrast-enhanced MRI revealed a left psoas abscess (PA). The patient has been given anti-infective treatment and underwent CT-guided drainage of left PA with a temporary drain. But the patient's condition did not improve significantly. Then, the colonoscopy revealed that it may be the PA secondary to inflammatory bowel disease. But the pathology was not in line with inflammatory bowel disease. We finally performed an ileostomy surgery and took the whole layer of intestinal wall for biopsy. The pathological result revealed that a large number of proliferative ganglion cells and circuitous hyperplastic nerve fibers were found in the submucosa and muscular layer of the intestinal wall. Given pathological results and clinical manifestations, the patient was diagnosed with IND-B.

Conclusion

In this case, we first report an extremely rare case of adult IND manifesting as PA. So, this unusual case provides a new supplement to adult cases of IND.

The utility of the 24-h delayed film of barium enema for detecting the dysganglionic bowel segment in Hirschsprung's disease

BACKGROUND

Preoperative evaluation of the dysganglionic bowel segment is critical for establishing the optimal resection strategy for Hirschsprung's disease (HSCR), which facilitates patient outcomes.

OBJECTIVE

We set out to determine the utility of the 24-h delayed film of barium retention in predicting the length of dysganglionic bowel segment in HSCR.

MATERIALS AND METHODS

A retrospective study of patients with clinically suspicious HSCR who underwent a preoperative 24-h delayed film of barium enema and were surgically treated from January 2015 to December 2019 was conducted.

RESULTS

Two hundred and 58 patients were enrolled in this study. The sensitivity, specificity, positive and negative predictive values (NPVs) of the 24-h delayed film of barium enema to predict the neuropathological segment were 89.1, 91.5, 91.3, and 89.4%, respectively. The Youden index was 80.6%, with a kappa value of 0.806 (P < 0.001). The correlation rate between barium retention level and pathological results was 72.7% (16/22) when aganglionosis was restricted within the mid-distal rectum (short-segment type), increasing to 92.0% (46/50) and 93.5% (174/186) for patients that had aganglionosis extended beyond the mid-distal rectum (classical type) and sigmoid colon (long-segment type), respectively. Lastly, patients younger than 3 months showed a lower correlation rate (72.2%) compared to patients aged 3-12 months (91.0%) and > 12 months (92.6%).

CONCLUSIONS

Our investigation of the 24-h delayed film of barium enema performed for patients suspected of having HSCR indicated that the barium retention level remains crucial in predicting dysganglionic bowel segment, which contributes to the decision-making for surgical physicians.

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.

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.

What should be the treatment for intestinal neuronal dysplasia type B? A comparative long-term follow-up study

PURPOSE

To present the long-term follow-up outcomes of patients with intestinal neuronal dysplasia type B (IND-B) managed either conservatively or surgically.

METHODS

We conducted an ambispective, observational, longitudinal, and comparative study. Clinical data were reviewed at the start of treatment. After a minimum period of five years, the patients participated in semi-structured interviews in which the bowel function score (BFS) was applied to assess intestinal function, a proposed intestinal symptom index (ISI) to assess clinical symptoms, and a classification of clinical prognosis to assess treatment success. Comparisons between the two types of treatment were performed by evaluating pre- and post-treatment criteria.

RESULTS

Fifty patients diagnosed with IND-B were included in the study. Thirty-eight patients underwent surgical treatment (26 elective surgical treatment for primary colorectal resection and 12 emergency colostomies for intestinal obstruction or enterocolitis). Twelve patients were managed conservatively. With the exception of the patients who required an emergency operation (n = 12), the two groups were composed of patients with severe constipation who had similar clinical and functional characteristics at the time of IND-B diagnosis. A better clinical response was observed in patients submitted to conservative treatment, with a greater increase in the BFS (16.5 [-4/+18] versus 4 [-15/+17]; p = 0.001), indicating better bowel function and a more pronounced drop in ISI (-6 [-7/-4] versus -4 [-6/+1]; p = 0.015), suggesting fewer symptoms. The percentage of patients who had a successful treatment was higher in the group treated conservatively (72.7% versus 42.3%; p = 0.03).

CONCLUSION

Conservative management showed better long-term outcomes than surgical management in children with IND-B.

Congenital Myenteric Hypoganglionosis

Congenital myenteric hypoganglionosis is a rare developmental disorder characterized clinically by severe and persistent neonatal intestinal pseudoobstruction. The diagnosis is established by the prevalence of small myenteric ganglia composed of closely spaced ganglion cells with sparse surrounding neuropil. In practice, the diagnosis entails familiarity with the normal appearance of myenteric ganglia in young infants and the ability to confidently recognize significant deviations in ganglion size and morphology. We review clinical, histologic, and immunohistochemical findings from 12 patients with congenital myenteric hypoganglionosis in comparison with similar data from age-matched controls and clearly delineate the diagnostic features of the condition. Practical guidelines are provided to assist surgical pathologists, who are likely to encounter this condition only infrequently. The diagnosis typically requires full-thickness intestinal biopsy as the abnormality is confined to the myenteric plexus in many patients. Immunohistochemistry for Hu C/D may be used to confirm hypoganglionosis. Reduced staining for calretinin and NeuN implicates a selective deficiency of intrinsic primary afferent neurons in this disease.

Rare case of adult intestinal hypoganglionosis and review of the literature

Intestinal hypoganglionosis is a rare condition in adults. We report a case of intestinal hypoganglionosis in the mid-distal transverse colon to splenic flexure in a 65-year-old female patient presenting with altered bowel habit and abdominal distension, and reviewed the current literature on this topic. Our patient had a medical history of neurofibromatosis type 1. A preoperative computed tomography (CT) scan demonstrated a grossly dilated transverse colon without obstruction. A laparotomy for subtotal colectomy was performed, with histopathology demonstrating intestinal hypoganglionosis.

Cholinergic innervation and ganglion cell distribution in Hirschsprung's disease

BACKGROUND

The diagnostic gold standard of Hirschsprung's disease (HD) is based on the histopathological assessment of colorectal biopsies. Although data on cholinergic innervation and ganglion cell (GC) distribution exist, only few studies have examined these two key features together. We assessed the pattern of cholinergic innervation and the amount of GCs in colorectal specimens of 14 HD patients.

METHODS

We established a semi-quantitative score for cholinergic innervation using acetylcholinesterase (AChE) enzyme histochemistry and quantitatively analyzed the number of GCs via NADH tetrazolium reductase (NADH) enzyme histochemistry. We examined both the entire length of the resected specimens as well as defined areas of the transition zone of both pathological and healthy appearing segment.

RESULTS

High AChE score values were associated with absence of GCs, and AChE scores were inversely correlated with the number of GCs. Nevertheless, we observed several cases in which one of the two features revealed a normal distribution pattern, whereas the other still displayed pathological features.

CONCLUSIONS

Our data support the need for transmural colon biopsies, to enable the best evaluation of both cholinergic innervation and GCs for a reliable assessment of HD.

ERNICA guidelines for the management of rectosigmoid Hirschsprung's disease

BACKGROUND

Hirschsprung's disease (HSCR) is a serious congenital bowel disorder with a prevalence of 1/5000. Currently, there is a lack of systematically developed guidelines to assist clinical decision-making regarding diagnostics and management.

AIMS

This guideline aims to cover the diagnostics and management of rectosigmoid HSCR up to adulthood. It aims to describe the preferred approach of ERNICA, the European Reference Network for rare inherited and congenital digestive disorders.

METHODS

Recommendations within key topics covering the care pathway for rectosigmoid HSCR were developed by an international workgroup of experts from 8 European countries within ERNICA European Reference Network from the disciplines of surgery, medicine, histopathology, microbiology, genetics, and patient organization representatives. Recommendation statements were based on a comprehensive review of the available literature and expert consensus. AGREE II and GRADE approaches were used during development. Evidence levels and levels of agreement are noted.

RESULTS

Thirty-three statements within 9 key areas were generated. Most recommendations were based on expert opinion.

CONCLUSION

In rare or low-prevalence diseases such as HSCR, there remains limited availability of high-quality clinical evidence. Consensus-based guidelines for care are presented.

Pediatric Intestinal Pseudo-obstruction in the Era of Genetic Sequencing

PURPOSE OF REVIEW

The purpose of this review is to discuss current knowledge on pediatric intestinal pseudo-obstruction. We will also review new mutations that have been identified through advancement in genetic testing, allowing for a better understanding of the underlying mechanisms of intestinal dysmotility and potential etiologies.

RECENT FINDINGS

With the advancements in genetic testing, new mutations have been identified in the diagnosis of megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS), a disorder leading to pediatric pseudo-obstruction. MYLK, LMOD1, MYL9, and MYH11 encode for various proteins within smooth muscle cells; abnormalities within these proteins lead to abnormal intestinal smooth muscle contractions. Chronic intestinal pseudo-obstruction (CIPO) is defined by symptoms of bowel obstruction in the absence of a lumen-occluding lesion. CIPO is a heterogeneous group of disorders caused by abnormalities in the enteric neurons, intestinal smooth muscle, and/or the interstitial cells of Cajal (ICC). Symptoms can be non-specific and etiologies include both primary and secondary causes of CIPO that contribute to the delay in recognizing this condition and making the correct diagnosis. Chronic intestinal pseudo-obstruction has been recognized in both adults and children with fundamental differences in the etiology, symptom onset, clinical features and natural history of this disorder. For this reason, it has been considered a separate entity referred to as pediatric intestinal pseudo-obstruction (PIPO).

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.

The Extent of the Transition Zone in Hirschsprung Disease

BACKGROUND

Retained transition zone is a leading cause of obstructive symptoms after pull-through operation in Hirschsprung's disease.

OBJECTIVE

We aimed to evaluate the extent of the histological transition zone in patients with Hirschsprung's disease.

DESIGN

We performed an observational study. DAB+ immunohistochemistry for Protein Gene Product 9.5 was used to evaluate the neuronal networks in serial sections of pull-through specimens obtained from children with Hirschsprung's disease (n = 12). Reference ranges for ganglion size/density and nerve trunk diameter were statistically determined using healthy controls obtained from colostomy specimens from children with anorectal malformations (n = 8). The transition zone was defined as ganglionic bowel exhibiting ganglion hypoplasia, hypertrophic nerve trunks, or partial circumference aganglionosis.

RESULTS

The mean submucosal nerve trunk diameter in controls was 19.56 μm +/- 3.87 μm. The median age at pull-through for Hirschsprung's disease was 5 months (3-14 months). The median length of the transition zone across the population was 8 cm (4-22 cm). Median transition zone extent was significantly longer in patients with long-segment aganglionosis (n = 6) compared to rectosigmoid aganglionosis (n = 6, 13 cm vs 6 cm, p = 0.041). Due to the age of the patients enrolled, long-term follow-up of bowel function is not yet available.

CONCLUSION

Our data suggest that, in children with rectosigmoid Hirschsprung's disease, the transition zone can extend for up to 13 cm. In children with long-segment disease, a longer transition zone is possible. Extended resection at a minimum 5 cm beyond the most distal ganglionic intra-operative biopsy and intra-operative histological examination of the proximal resection margin are required to minimize transition zone pull-through.

LEVEL OF EVIDENCE

2.

Acquired segmental colonic hypoganglionosis in an adult Caucasian male: A case report

BACKGROUND

Hypoganglionosis is a rare condition that most often presents with abnormal gastrointestinal transit and usually arises in early childhood or adolescence. Two types have been described (Type I and Type II). The adult-onset form (acquired hypoganglionosis) is extremely uncommon and is thought to arise due to cellular remodelling as a result of chronic inflammation. It differs from Hirschprung’s disease in that there is a reduction in ganglion cells in the colonic neural plexuses as opposed to being completely absent.

CASE SUMMARY

A 31 year-old male presented to hospital with recurrent abdominal pain and vomiting over thirteen months. Abdominal computed tomography scans demonstrated thickening and stranding affecting the transverse, descending and sigmoid colon. Endoscopic appearances were non-specific but confirmed a mixed picture of mucosal inflammation and necrosis in various stages of healing. Numerous investigations were performed to elucidate an underlying aetiology but neither an infective nor ischaemic cause could be proven. Biopsy features were not typical of inflammatory bowel disease. Due to persistence of his symptoms and failure of medical management, a segmental colectomy was performed. Histological examination of the specimen revealed an unexpected finding of segmental hypoganglionosis. Complete surgical excision of the diseased segment of colon was curative and since his operation the patient has had no recurrence of symptoms requiring hospitalisation.

CONCLUSION

Our case serves to raise awareness of acquired hypoganglionosis as a rare condition that can result from chronic colitis.

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.

The Reality of Multiple Endocrine Neoplasia Type 2B Diagnosis: Awareness of Unique Physical Appearance Is Important

BACKGROUND

Multiple endocrine neoplasia type 2B (MEN2B) is an extremely rare syndrome mainly caused by RET918 germline mutations. MEN2B typically causes medullary thyroid carcinoma (MTC), pheochromocytoma, and unique physical characteristics including mucosal neuroma, distinctive facial appearance, and Marfanoid habitus. Most patients have abdominal symptoms such as bloating, intermittent constipation, and diarrhea. MTC is the most important determinant of mortality in patients with MEN2B. Establishing the diagnosis of MEN2B at a curative stage of MTC is crucial.

CASE PRESENTATION

We have encountered four patients with MEN2B. Two were hereditary cases from the same family, and two were considered de novo cases with phenotypically normal parents. Mean age at diagnosis was 25.5 years (range, 13-39 years). Although all patients had shown mucosal neuroma on the lips and tongue, in addition to gastrointestinal symptoms from infancy, diagnoses were made from symptomatic MTC even for the hereditary patients (our index case was a 14-year-old girl, whose mother was subsequently diagnosed with advanced MTC). Genetic tests for RET mutations revealed the M918T mutation in all patients. Two patients developed pheochromocytoma, two died from distant metastases of MTC, and two received treatment for multiple metastases of MTC (one with vandetanib).

CONCLUSIONS

In our patients with MEN2B, prophylactic or early thyroidectomy could not be performed. The characteristic phenotype associated with MEN2B is almost always seen prior to detection of MTC or pheochromocytoma. Knowledge about the non-endocrine manifestations of MEN2B needs to be shared among pediatricians and gastroenterologists.

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.

A Rare Case of Adult-Onset Rectosigmoid Hypoganglionosis

Patient: Male, 20

Final Diagnosis: Rectosigmoid hypoganglionosis

Symptoms: Severe abdominal pain • obstipation • vomiting • shortness of breath • palpitations

Medication: —

Clinical Procedure: Hartmann’s procedure

Specialty: Surgery

Development of Nerve Fibre Diameter in Young Infants With Hirschsprung Disease

OBJECTIVES

Finding thickened nerve fibres is one of the key elements in the diagnosis of Hirschsprung disease (HD); however, its value at different ages remains uncertain. Nerve fibre diameters <40 μm can be observed in infants younger than 8 weeks, despite the presence of HD. The aim of this study was to identify a change in maximum nerve fibre diameter in HD patients, measured before and after 8 weeks of age.

METHODS

Nerve fibre diameter was retrospectively evaluated in tissue of 20 infants treated for definite HD. Rectal suction biopsies (RSBs) obtained within the first 8 weeks of life (T1) and resected bowel obtained during primary surgery at an average of 24.7 weeks (T2), were assessed. The 2 thickest nerve fibre diameter recordings at T1 and T2 were compared in each subject, to examine changes in nerve trunk diameter with increasing age.

RESULTS

In 13 cases (65%), nerve fibre diameters were ≥40 μm at T1 and T2. Six subjects (30%) had nerve trunk diameters <40 μm at T1; however, they experienced diameter increases to ≥40 μm by T2. Thus, at T2, 19 subjects (95%) had diameter recordings ≥40 μm. Nerve fibre diameter in the remaining case (5%) stayed consistent at <40 μm at T1 and T2, despite the presence of HD.

CONCLUSIONS

After the first 8 weeks of life, nerve fibre measurements appear to be associated with HD. Measuring the 2 thickest nerve fibres can support typical HD diagnosis criteria beyond 8 weeks of age, but is not superior to histopathological confirmation of aganglionosis.

A case of single incision laparoscopic total colectomy for intestinal neuronal dysplasia type B

•

In patients with refractory constipation, it is necessary to care in mind that some patients require surgery.

•

Single incision laparoscopic surgery (SILS) is regarded as the major advance in minimally invasive surgery.

•

Total colectomy by SILS is very useful for the patients with intestinal neuronal dysplasia-type B.

Introduction

Intestinal neuronal dysplasia type B (IND-B) is an infrequent disease of the submucosal plexus of intestine manifesting chronic intestinal obstruction or severe chronic constipation. IND is rarely reported in adult patients.

Presentation of a case

The present study reports on the case of a 36 year-old woman suffering from longstanding chronic constipation and who was diagnosed with severe constipation in more than 20 years. Although she began to take a large amount of stimulant laxatives, such as “senna” and “bisacodyl”, constipation symptoms did not improve, she was admitted to our hospital. It was diagnosed with refractory constipation of the medication treatment-resistance, total colectomy with ileorectal anastomosis by single incision laparoscopic surgery (SILS) was performed. The final pathological diagnosis was IND-B.

Discussion

Refractory constipation after medical treatment is often seen in young generation. SILS has benefits of better cosmesis, reduced morbidity, reduced postoperative pain, and reduced length of hospital stay.

Conclusion

For the patients with refractory constipation associated with neuropathy such as IND, total colectomy by SILS was very effective.

A critical appraisal of the morphological criteria for diagnosing intestinal neuronal dysplasia type B

Intestinal neuronal dysplasia type B is a controversial entity expressed by complex changes in the enteric nervous system. Diagnosis depends on rectal biopsy histopathology and diagnostic criteria, both qualitative and quantitative, have changed over time, hindering the diagnostic practice. We analyzed the morphological criteria for the histological diagnosis of intestinal neuronal dysplasia type B in a series of patients with intestinal neuronal dysplasia type B according to the 1990 Frankfurt Consensus criteria and verified the applicability of the numerical criteria proposed by Meier-Ruge et al in 2004 and 2006. Qualitative criteria adopted for the histological diagnosis of intestinal neuronal dysplasia type B included hyperplasia of the submucous plexus with hyperganglionosis and hypertrophy of the nerve trunks. Quantitative criteria considered more than 20% giant ganglia in the submucosa, with more than eight neurons each on 25 ganglia, and children aged over 1 year. Distal colon surgical specimens from 29 patients, aged 0-16 years, diagnosed with intestinal neuronal dysplasia type B were retrospectively analyzed using sections processed for conventional histology (H&E) and calretinin immunohistochemistry. Hyperplasia of the submucosal nerve plexi with hyperganglionosis and hypertrophy of the nerve trunks was observed in all cases. Ganglia with small, immature neurons were detected in the majority of cases. Quantitative analysis confirmed hyperganglionosis (mean number=10.7 neurons per ganglion) and hypertrophy of the nerve trunks (median=44.6 μm thickness). Neurons showed immunostaining for calretinin, but neuron counts in calretinin-stained sections were lower compared with H&E (P<0.01). No significant differences were verified between children aged under and over 1 year regarding hyperganglionosis (P=0.79), neuron counts (P=0.36), and immature ganglia (P=0.66). Only one patient met the numerical criteria proposed by Meier-Ruge et al in 2004 and 2006. In conclusion, the numerical criteria showed limited applicability when transposed to conventional histopathology. Children aged over 1 year presented very similar histological features of neuronal immaturity to younger children, questioning the need for an age criterion when diagnosing intestinal neuronal dysplasia type B.

Intestinal Hypoganglionosis Leading to Intestinal Failure and the Compassionate Use of Omegaven™

Intestinal hypoganglionosis is a rare innervation disorder that provides numerous nutritional, medical and surgical challenges. In this case report, we present a case of a newborn with intestinal hypoganglionosis leading to intestinal failure and intestinal failure-associated liver disease who responded to Omegaven™, a fat emulsion comprised of omega-3 fatty acids. Omegaven™ has been shown to be beneficial in the management of cholestatic liver injury. Clinical success with Omegaven™ was seen in this patient with a clear decrease in aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and complete resolution of cholestasis with a direct bilirubin of zero within two weeks of initiation of Omegaven™. No current guidelines for the diagnosis and management of hypoganglionosis are available. We recommend a multidisciplinary approach and the use of novel therapies such as fat emulsions composed of omega-3 fatty acids for improved patient outcomes. Appropriate compassionate use protocols should be obtained from the Food and Drug Administration prior to initiation of Omegaven™.

Hirschsprung's disease: clinical dysmorphology, genes, micro-RNAs, and future perspectives

On the occasion of the 100th anniversary of Dr. Harald Hirschsprung's death, there is a worldwide significant research effort toward identifying and understanding the role of genes and biochemical pathways involved in the pathogenesis as well as the use of new therapies for the disease harboring his name (Hirschsprung disease, HSCR). HSCR (aganglionic megacolon) is a frequent diagnostic and clinical challenge in perinatology and pediatric surgery, and a major cause of neonatal intestinal obstruction. HSCR is characterized by the absence of ganglia of the enteric nervous system, mostly in the distal gastrointestinal tract. This review focuses on current understanding of genes and pathways associated with HSCR and summarizes recent knowledge related to micro RNAs (miRNAs) and HSCR pathogenesis. While commonly sporadic, Mendelian patterns of inheritance have been described in syndromic cases with HSCR. Although only half of the patients with HSCR have mutations in specific genes related to early embryonic development, recent pathway-based analysis suggests that gene modules with common functions may be associated with HSCR in different populations. This comprehensive profile of functional gene modules may serve as a useful resource for future developmental, biochemical, and genetic studies providing insights into the complex nature of HSCR.

Gene-environment interactions and the enteric nervous system: Neural plasticity and Hirschsprung disease prevention

Intestinal function is primarily controlled by an intrinsic nervous system of the bowel called the enteric nervous system (ENS). The cells of the ENS are neural crest derivatives that migrate into and through the bowel during early stages of organogenesis before differentiating into a wide variety of neurons and glia. Although genetic factors critically underlie ENS development, it is now clear that many non-genetic factors may influence the number of enteric neurons, types of enteric neurons, and ratio of neurons to glia. These non-genetic influences include dietary nutrients and medicines that may impact ENS structure and function before or after birth. This review summarizes current data about gene-environment interactions that affect ENS development and suggests that these factors may contribute to human intestinal motility disorders like Hirschsprung disease or irritable bowel syndrome.

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.

Childhood Functional Gastrointestinal Disorders: Neonate/Toddler

In 2006, a consensus concerning functional gastrointestinal intestinal disorders (FGIDs) in infants and toddlers was described. At that time little evidence regarding epidemiology, pathophysiology, diagnostic work-up, treatment strategies and follow-up was available. Consequently the criteria for the clinical entities were more experience than evidence based. In the past decade, new insights have been gained in the different FGIDs in these age groups. Based on those, further revisions have been made to the criteria. The description of infant colic has been expanded to include criteria for the general pediatrician and specific criteria for researchers. The greatest change was the addition of a paragraph regarding the neurobiology of pain in infants and toddlers, including the understanding of the neurodevelopment of nociception and of the wide array of factors that may impact the pain experience.

Pediatric intestinal motility disorders

Pediatric intestinal motility disorders affect many children and thus not only impose a significant impact on pediatric health care in general but also on the quality of life of the affected patient. Furthermore, some of these conditions might also have implications for adulthood. Pediatric intestinal motility disorders frequently present as chronic constipation in toddler age children. Most of these conditions are functional, meaning that constipation does not have an organic etiology, but in 5% of the cases, an underlying, clearly organic disorder can be identified. Patients with organic causes for intestinal motility disorders usually present in early infancy or even right after birth. The most striking clinical feature of children with severe intestinal motility disorders is the delayed passage of meconium in the newborn period. This sign is highly indicative of the presence of Hirschsprung disease (HD), which is the most frequent congenital disorder of intestinal motility. HD is a rare but important congenital disease and the most significant entity of pediatric intestinal motility disorders. The etiology and pathogenesis of HD have been extensively studied over the last several decades. A defect in neural crest derived cell migration has been proven as an underlying cause of HD, leading to an aganglionic distal end of the gut. Numerous basic science and clinical research related studies have been conducted to better diagnose and treat HD. Resection of the aganglionic bowel remains the gold standard for treatment of HD. Most recent studies show, at least experimentally, the possibility of a stem cell based therapy for HD. This editorial also includes rare causes of pediatric intestinal motility disorders such as hypoganglionosis, dysganglionosis, chronic intestinal pseudo-obstruction and ganglioneuromatosis in multiple endocrine metaplasia. Underlying organic pathologies are rare in pediatric intestinal motility disorders but must be recognized as early as possible.

Glycerin suppositories used prophylactically in premature infants (SUPP) trial: a study protocol for a pilot randomized controlled trial

BACKGROUND

Feeding is a significant challenge for premature infants in the neonatal intensive care unit (NICU). These patients are often treated with glycerin suppositories to stimulate the passage of meconium and prevent feeding intolerance. Unfortunately, the evidence for this practice is inconclusive.

METHODS/DESIGN

This protocol is for an external pilot study that will assess the feasibility of a superiority, placebo-controlled, parallel-design, multicenter randomized controlled trial. Participants are premature infants treated in a level 3 NICU with a gestational age 24 to 32 weeks and/or birth weight of 500 to 1500 g. Thirty participants will be recruited as part of this external pilot study. Participants will be randomized to glycerin suppository (250 mg) or placebo starting 48 to 72 h after birth and continuing once daily until meconium evacuation is complete or for a maximum of 12 days. The placebo consists of a 250-mg glycerin suppository placed in the diaper rather than the rectum. Study treatments are administered by the charge nurse on duty who is not otherwise involved in patient care. All other clinicians and research personnel will remain blinded. Outcomes for the pilot study are percentage of eligible participants randomized, percentage of infants reaching full enteral feeds, cost, and treatment-related adverse events (rectal bleeding, rectal perforation, and anal fissure).

DISCUSSION

This external pilot study will assess the feasibility of a multicenter randomized controlled trial of glycerin suppositories in premature infants. The subsequent multicenter trial will have sufficient power to determine whether this treatment strategy is associated with decreased time to full enteral feeds.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02153606.

A Hypothesis for Examining Skeletal Muscle Biopsy-Derived Sarcolemmal nNOSμ as Surrogate for Enteric nNOSα Function

The pathophysiology of gastrointestinal motility disorders is controversial and largely unresolved. This provokes empiric approaches to patient management of these so-called functional gastrointestinal disorders. Preliminary evidence demonstrates that defects in neuronal nitric oxide synthase (nNOS) expression and function, the enzyme that synthesizes nitric oxide (NO), the key inhibitory neurotransmitter mediating mechano-electrical smooth muscle relaxation, is the major pathophysiological basis for sluggishness of oro-aboral transit of luminal contents. This opinion is an ansatz of the potential of skeletal muscle biopsy and examining sarcolemmal nNOSμ to provide complementary insights regarding nNOSα expression, localization, and function within enteric nerve terminals, the site of stimulated de novo NO synthesis. The main basis of this thesis is twofold: (a) the molecular similarity of the structures of nNOS α and μ, similar mechanisms of localizations to “active zones” of nitrergic synthesis, and same mechanisms of electron transfers during NO synthesis and (b) pragmatic difficulty to routinely obtain full-thickness biopsies of gastrointestinal tract, even in patients presenting with the most recalcitrant manifestations of stasis and delayed transit of luminal contents. This opinion attempts to provoke dialog whether this approach is feasible as a surrogate to predict catalytic potential of nNOSα and defects in nitrergic neurotransmission. This discussion makes an assumption that similar molecular mechanisms of nNOS defects shall be operant in both the enteric nerve terminals and the skeletal muscles. These overlaps of skeletal and gastrointestinal dysfunction are largely unknown, thus meriting that the thesis be validated in future by proof-of-principle experiments.

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.