Hirschsprung's disease

Ultrashort-Segment Hirschsprung's Disease Complicated by Megarectum and Obstructive Uropathy: A Case Report

Adult Hirschsprung's disease (AHD) is a rare condition characterized by a shortened aganglionic segment in the distal colon or rectum that is diagnosed after the age of 10. Diagnostic challenges stem from its rarity, nonspecific presentation, and often delayed consideration following emergent interventions. This report details the case of a 33-year-old male who presented with chronic constipation and abdominal pain, leading to a severe bowel obstruction attributed to self-reported Hirschsprung's disease (HD). Clinical, radiological, and historical aspects were suggestive of AHD, but definitive diagnostic procedures, including manometry and biopsy, were hindered by the patient's deteriorating condition. Exploratory laparotomy unveiled a secondary small bowel obstruction due to volvulus, necessitating immediate intervention, resulting in the removal of 4000 cc of fecal material. A comprehensive resection involving mid-to-distal transverse colon, left colon, sigmoid colon, and proximal rectum with the creation of Hartman's colostomy was performed due to the patient's worsening clinical status. We present a case of possible ultrashort-segment Hirschsprung's disease (USHD) and sketch a classic presentation of AHD. This endeavor aims to enhance awareness and consideration of AHD and/or USHD within the spectrum of potential diagnoses for chronic constipation when relevant and demonstrate the effectiveness of surgical intervention in this population.

Short and Long-Term Outcomes in Hirschsprung Disease: Are the Syndrome-Associated Patients Really Doing Worse?

INTRODUCTION

Given the lack of data to help caregivers in the follow-up of Hirschsprung disease (HD), this study aimed to compare the functional outcomes of isolated Hirschsprung disease (I-HD) to syndrome-associated Hirschsprung disease (SA-HD) at 1, 3, 5, and 10 years.

METHODS

A retrospective chart review of patients diagnosed with HD between January 1990 and May 2021 at our pediatric center was performed to collect data on patient characteristics, investigations, and treatments. Ninety-five patients were identified, of whom 76 were included in the study. SA-HD is defined as a syndrome known to be associated with HD or cognitive impairment.

RESULTS

Patient characteristics were comparable between groups ( P > 0.05). There were 52 patients with I-HD and 24 with SA-HD. The patients median age was 9 days at diagnosis and 1.5 month at surgery. SA-HD patients became bowel continent at a significantly older age (mean age 8.43 vs 4.94 years, P = 0.0471) and received more bowel continence medications. At 5 years, SA-HD patients requiring ≥2 medications for bowel continence represented 54.5% versus 11.1% of I-HD patients ( P = 0.009). Lastly, SA-HD patients had urinary incontinence at a significantly older age ( P = 0.0136, 5 years).

CONCLUSION

Clinicians should be aware that SA-HD patients are more prone to bladder dysfunction and became bowel continent at an older age than I-HD patients. They need more and prolonged bowel management medications, and other important complications need to be addressed in patient care. These results should prompt a longer follow-up period for these patients, especially in SA-HD.

Single-cell profiling coupled with lineage analysis reveals vagal and sacral neural crest contributions to the developing enteric nervous system

During development, much of the enteric nervous system (ENS) arises from the vagal neural crest that emerges from the caudal hindbrain and colonizes the entire gastrointestinal tract. However, a second ENS contribution comes from the sacral neural crest that arises in the caudal neural tube and populates the post-umbilical gut. By coupling single-cell transcriptomics with axial-level-specific lineage tracing in avian embryos, we compared the contributions of embryonic vagal and sacral neural crest cells to the chick ENS and the associated peripheral ganglia (Nerve of Remak and pelvic plexuses). At embryonic day (E) 10, the two neural crest populations form overlapping subsets of neuronal and glia cell types. Surprisingly, the post-umbilical vagal neural crest much more closely resembles the sacral neural crest than the pre-umbilical vagal neural crest. However, some differences in cluster types were noted between vagal and sacral derived cells. Notably, RNA trajectory analysis suggests that the vagal neural crest maintains a neuronal/glial progenitor pool, whereas this cluster is depleted in the E10 sacral neural crest which instead has numerous enteric glia. The present findings reveal sacral neural crest contributions to the hindgut and associated peripheral ganglia and highlight the potential influence of the local environment and/or developmental timing in differentiation of neural crest-derived cells in the developing ENS.

Clinical Characteristics of Adult Functional Constipation Patients with Rectoanal Areflexia and Their Response to Biofeedback Therapy

Background: The London Classification for anorectal physiological dysfunction specifically proposes rectoanal areflexia (RA), which means the absence of a rectoanal inhibitory reflex (RAIR) based on a manometric diagnosis. Although RA is not observed in healthy people, it can be found in adult patients with functional constipation (FC). This study describes the clinical manifestations of adult patients with FC and RA and their response to biofeedback therapy (BFT). Methods: This retrospective study reviewed the reports of high-resolution anorectal manometry (HR-ARM) and the efficacy of BFT in adult patients with FC. In addition, the Constipation Scoring System (CSS) scale, Patient Assessment of Constipation Symptoms (PAC-SYM) scale, Patient Assessment of Constipation Quality of Life (PAC-QOL) scale, Zung’s Self-Rating Anxiety Scale (SAS), Zung’s Self-Rating Depression Scale (SDS), balloon expulsion test (BET), and the use of laxatives were assessed. Results: A total of 257 adult patients diagnosed with FC were divided into the RA group (n = 89) and the RAIR group (n = 168). In the RA and RAIR groups, 60 (67.4%) and 117 (69.6%) patients, respectively, had dyssynergic defecation (DD) during simulated defecation. Type II pattern of dyssynergia was most frequently observed in both groups. Compared with the RA group, the RAIR group showed a higher CSS score, physical discomfort score, and prevalence of inadequate relaxation of the anal sphincter (p < 0.001, p = 0.036, and p = 0.017, respectively). The anxiety and depression scores were not different between the two groups. The proportion of patients using volumetric and stimulant laxatives and their combination was significantly higher in FC patients with RA, whereas the efficacy of BFT was significantly lower (p = 0.005, p < 0.001, p = 0.045, and p = 0.010, respectively). Conclusion: Adult FC patients with RA may suffer more severe constipation and have a lower efficacy of BFT compared with those with RAIR.

Nationwide outcomes of newborns with rectosigmoid versus long-segment Hirschsprung disease

PURPOSE

Hirschsprung Disease (HD) is a common congenital intestinal disorder. While aganglionosis most commonly affects the rectosigmoid colon (rectosigmoid HD), outcomes for patients in which aganglionosis extends to more proximal segments (long-segment HD) remain understudied. This study sought to compare postoperative outcomes among newborns with rectosigmoid and long-segment HD.

METHODS

The Nationwide Readmission Database was queried from 2016 to 2018 for newborns with HD. Newborns were stratified into those with rectosigmoid or long-segment HD. Those who received no rectal biopsy or pull-through procedure during their newborn hospitalization were excluded. A propensity score-matched analysis (PSMA) of newborns with either type of HD was constructed utilizing 17 covariates including demographics, comorbidities, and congenital-perinatal conditions.

RESULTS

There were 1280 newborns identified with HD (82% rectosigmoid HD, 18% long-segment HD). Patients with rectosigmoid HD had higher rates of laparoscopic resections (35% vs. 12%) and less frequently received a concomitant ostomy (14% vs. 84%), both p < 0.001. Patients with long-segment HD were more likely to have a delayed diagnosis (12% vs. 5%) and require multiple bowel operations (19% vs. 4%), both p < 0.001. They experienced higher rates of complications, including small bowel obstructions (10% vs. 1%), infections (45% vs. 20%), and Hirschsprung-associated enterocolitis (11% vs. 5%), all p < 0.001. After PSMA, newborns with long-segment HD were found to have a longer length of stay and higher hospitalization costs.

CONCLUSION

Newborns with long-segment HD experience significant delays in diagnosis, surgery, and complications compared to those with rectosigmoid HD. This information should be utilized to improve healthcare delivery for this patient population.

TYPE OF STUDY

Retrospective comparative study.

LEVEL OF EVIDENCE

III.

Quality of life outcomes in children after surgery for Hirschsprung disease and anorectal malformations: a systematic review and meta-analysis

Background

No systematic review and meta-analysis to date has examined multiple child and parent-reported social and physical quality of life (QoL) in pediatric populations affected by Hirschsprung’s disease (HD) and anorectal malformations (ARM). The objective of this systematic review is to quantitatively summarize the parent-reported and child-reported psychosocial and physical functioning scores of such children.

Methods

Records were sourced from the CENTRAL, EMBASE, and MEDLINE databases. Studies that reported child and parent reported QoL in children with HD and ARM, regardless of surgery intervention, versus children without HD and ARM, were included. The primary outcome was the psychosocial functioning scores, and the secondary outcomes were the presence of postoperative constipation, postoperative obstruction symptoms, fecal incontinence, and enterocolitis. A random effects meta-analysis was used.

Results

Twenty-three studies were included in the systematic review, with 11 studies included in the meta-analysis. Totally, 1678 total pediatric patients with HD and ARM underwent surgery vs 392 healthy controls. Pooled parent-reported standardized mean (SM) scores showed better social functioning after surgery (SM 91.79, 95% CI (80.3 to 103.3), I2=0). The pooled standardized mean difference (SMD) showed evidence for parent-reported incontinence but not for constipation in children with HD and ARM after surgery that had a lower mean QoL score compared with the normal population (SMD −1.24 (-1.79 to –0.69), I2=76% and SMD −0.45, 95% CI (−1.12 to 0.21), I2=75%). The pooled prevalence of child-reported constipation was 22% (95% CI (16% to 28%), I2=0%). The pooled prevalence of parent-reported postoperative obstruction symptoms was 61% (95% CI (41% to 81%), I2=41%).

Conclusion

The results demonstrate better social functioning after surgery, lower QoL scores for incontinence versus controls, and remaining constipation and postoperative obstruction symptoms after surgery in children with HD and ARM.

Determining the correct resection level in patients with Hirschsprung disease using contrast enema and full thickness biopsies: Can the diagnostic accuracy be improved by examining submucosal nerve fiber thickness?

BACKGROUND

Intraoperative resection level in patients with Hirschsprung disease (HD) is determined by contrast enema, surgeon's intraoperative judgement and full thickness biopsy (FTB) identifying ganglia. This study aims to evaluate diagnostic accuracy of contrast enema and FTB in determination of resection level and whether this can be improved by measuring submucosal nerve fiber diameter.

METHODS

We retrospectively analyzed contrast enema and intraoperative FTBs obtained in our center, determining diagnostic accuracy for level of resection. Gold standard was pathological examination of resection specimen. Secondly, we matched transition zone pull-through (TZPT) patients with non-TZPT patients, based on age and length of resected bowel, to blindly compare nerve fibers diameters between two groups using group comparison.

RESULTS

From 2000-2021, 209 patients underwent HD surgery of whom 180 patients (138 males; median age at surgery: 13 weeks) with 18 TZPTs (10%) were included. Positive predictive value of contrast enema was 65.1%. No caliber change was found in patients with total colon aganglionosis (TCA). Negative predictive value of surgeon's intraoperative judgement and FTB in determining resection level was 79.0% and 90.0% (91.2% single-stage, 84.4% two-stage surgery) respectively. Mean nerve fiber diameter in TZPT was 25.01 µm (SD= 5.63) and in non-TZPT 24.35 µm (SD= 6.75) (p = 0.813).

CONCLUSION

Determination of resection level with combination of contrast enema, surgeon's intraoperative judgement and FTB results in sufficient diagnostic accuracy in patients with HD. If no caliber change is seen with contrast enema, TCA should be considered. Resection level or transition zone cannot be determined by assessment of submucosal nerve fiber diameter in FTB.

TYPE OF STUDY

clinical research paper.

RET signaling pathway and RET inhibitors in human cancer

Rearranged during transfection (RET) receptor tyrosine kinase was first identified over thirty years ago as a novel transforming gene. Since its discovery and subsequent pathway characterization, RET alterations have been identified in numerous cancer types and are most prevalent in thyroid carcinomas and non-small cell lung cancer (NSCLC). In other tumor types such as breast cancer and salivary gland carcinomas, RET alterations can be found at lower frequencies. Aberrant RET activity is associated with poor prognosis of thyroid and lung carcinoma patients, and is strongly correlated with increased risk of distant metastases. RET aberrations encompass a variety of genomic or proteomic alterations, most of which confer constitutive activation of RET. Activating RET alterations, such as point mutations or gene fusions, enhance activity of signaling pathways downstream of RET, namely PI3K/AKT, RAS/RAF, MAPK, and PLCγ pathways, to promote cell proliferation, growth, and survival. Given the important role that mutant RET plays in metastatic cancers, significant efforts have been made in developing inhibitors against RET kinase activity. These efforts have led to FDA approval of Selpercatinib and Pralsetinib for NSCLC, as well as, additional selective RET inhibitors in preclinical and clinical testing. This review covers the current biological understanding of RET signaling, the impact of RET hyperactivity on tumor progression in multiple tumor types, and RET inhibitors with promising preclinical and clinical efficacy.

Emerging Roles of Circ-ZNF609 in Multiple Human Diseases

Circular RNAs (circRNAs) are a special type of endogenous RNAs with extensive roles in multiple human diseases. They are formed by back-splicing of partial sequences of the parental precursor mRNAs. Unlike linear RNAs, their covalently closed loop structure without a 5′ cap and a 3′ polyadenylated tail confers on them high stability and they are difficult to be digested by RNase R. Increasing evidence has proved that aberrant expressions of many circRNAs are detected and that circRNAs exert essential biological functions in disease development and progression via acting as a molecular sponge of microRNA, interacting with proteins as decoys or scaffolds, or self-encoding small peptides. Circular RNA zinc finger protein 609 (circ-ZNF609) originates from exon2 of ZNF609, which is located at chromosome 15q22.31, and it has recently been proved that it can translate into a protein. Being aberrantly upregulated in various diseases, it could promote malignant progression of human tumors, as well as tumor cell proliferation, migration, and invasion. Here in this review, we concluded the biological functions and potential mechanisms of circ-ZNF609 in multiple diseases, which could be further explored as a targetable molecule in future accurate diagnosis and prognosis.

Aberrant high expression of the TET1 gene in Hirschsprung's disease

BACKGROUND

The pathogenesis of Hirschsprung's disease (HSCR) remains unclear but might involve genes participating in neural crest development. Gene methylation controls the expression of many genes and is involved in the development and migration of neural crest cells, but the involvement of demethylation in HSCR is unknown. This study aimed to investigate the expression of ten-eleven translocation methylcytosine dioxygenase 1 (TET1) (a demethylation protein) in patients with HSCR.

METHODS

This is a retrospective study of surgical specimens from paediatric patients with and without HSCR (e.g., intussusception and incarcerated hernia) obtained from 07/2015 to 08/2017. TET1 expression was determined by qRT-PCR, western blotting, and immunohistochemistry. The levels of 5-hydroxymethylcytosine were determined by the dot blot assay.

RESULTS

The specimens of 35 patients with HSCR and 25 controls were collected. The median TET1 mRNA expression values were 1.028 [HSCR-stenotic (S)], 0.908 [HSCR-dilated (D)], and 0.467 (control) (HSCR-S vs. control: P = 0.002; HSCR-D vs. control: P = 0.008; HSCR-S vs. HSCR-D: P = 0.44). TET1 protein levels followed a similar pattern. The intensity of immunostaining identified higher expression of TET1 in HSCR colon tissues compared with control tissues. The 5-hmC levels in HSCR stenotic segment samples were significantly higher than those in controls.

CONCLUSION

The expression of TET1 is higher in paediatric patients with HSCR than in controls. DNA demethylation initiated by TET1 may be related to HSCR, which demonstrates that TET1 may play a role in the development of HSCR.

Ultra high frequency ultrasonography to distinguish ganglionic from aganglionic bowel wall in Hirschsprung disease: A first report

BACKGROUND/PURPOSE

In Hirschsprung disease (HD) surgery, confirming ganglionic bowel is essential. A faster diagnostic method than the current frozen biopsy is desirable. This study investigated whether aganglionic and ganglionic intestinal wall can be distinguished from each other by ultra high frequency ultrasound (UHF ultrasound).

METHODS

In an HD center during 2019, intestinal walls of recto-sigmoid specimens from HD patients were examined ex vivo with a 70 MHz UHF ultrasound transducer. Data from four sites were described. Histopathologic analysis was compared to the ultrasonography outcome at each site. Each patient's specimen served as its own control.

RESULTS

11 resected recto-sigmoid specimens (median 20 cm long [range 6.5-33]) with transition zones of 5 cm (2-11 cm) were taken from children aged 22 days (13-48) weighing 3668 g (3500-5508); 44 key sites were analyzed. There was full concordance for 42/44 (95%) key sites and 10 of 11 (91%) specimens. The specimen with discordance of two key sites contained a segment of aganglionosis (3 cm) and a transition zone (1 cm): the site discordance was limited to the transition zone ends.

CONCLUSIONS

This first report on UHF ultrasound in recto-sigmoid HD shows promising results in identifying aganglionosis, transition zones and ganglionic bowel. Further in vivo studies are required.

Literature review: enteric nervous system development, genetic and epigenetic regulation in the etiology of Hirschsprung's disease

Hirschsprung's disease (HSCR) is a developmental disorder of the enteric nervous system (ENS) derived from neural crest cells (NCCs), which affects their migration, proliferation, differentiation, or preservation in the digestive tract, resulting in aganglionosis in the distal intestine. The regulation of both NCCs and the surrounding environment involves various genes, signaling pathways, transcription factors, and morphogens. Therefore, changes in gene expression during the development of the ENS may contribute to the pathogenesis of HSCR.

This review discusses several mechanisms involved in the development of ENS, confirming that deviant genetic and epigenetic patterns, such as DNA methylation, histone modification, and microRNA (miRNA) regulation, can contribute to the development of neurocristopathy. Specifically, the epigenetic regulation of miRNA expression and its relationship to cellular interactions and gene activation through various major pathways in Hirschsprung's disease will be discussed.

Adult Hirschsprung's disease: A case report and literature review

•

Adult Hirschprung’s Disease (AHD) can be a difficult diagnosis to make, due to its rarity.

•

We report a possible case of AHD and conduct a systematic review of the literature.

•

A typical patient would be male, average age of 30-years-old, with a history of chronic constipation complicated by repeated acute obstruction.

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Surgical resection, such as with Duhamel’s procedure, is curative.

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Early identification of these patients and definitive diagnoses would eliminate unnecessary and ineffective surgical interventions.

Introduction & importance

Adult Hirschsprung’s disease (AHD) is a difficult diagnosis to make due to its rarity, frequently after emergency interventions have been conducted. We present a case of possible AHD and sketch a classic presentation of Adult Hirschsprung’s Disease. This would help recognize and include AHD in the differential diagnoses of chronic constipation where appropriate.

Case presentation

The case involved a 41-year-old male with a history of multiple abdominal surgeries for volvuli and a ventral hernia repair complicated by post-operative SBO. Presenting symptoms were chronic constipation, abdominal colic, and dilation. SBO secondary to volvulus was discovered, decompressed, and emptied of 3000cc fecal material in the OR. His case was again complicated twice by SBO which led to the suspicion of AHD and instigated this systematic review. Papers were extracted from the EBSCO and PubMed databases. Papers were excluded if patients were younger than 10 years old.

Clinical discussion

The classic patient will be a male over the age of 10 years old with an average age of 30 years old and a long history of chronic constipation, often complicated by an acute symptomatic obstruction. Patients may have had a history of multiple surgical or non-surgical interventions to relieve their constipation.

Conclusion

AHD is being seen more frequently with the increasing availability of healthcare in underserved areas of the world. Duhamel’s procedure is the most effective procedure after diagnosis has been made. Barium enema and a biopsy show hypo- or a-ganglionic segments that are to be resected for curative purposes.

The not-so-rare absent RAIR: Internal anal sphincter achalasia in a review of 1072 children with constipation undergoing high-resolution anorectal manometry

BACKGROUND

Our objective is to describe the prevalence of patients with internal anal sphincter achalasia (IASA) without Hirschsprung disease (HD) among children undergoing anorectal manometry (ARM) and their clinical characteristics.

METHODS

We performed a retrospective review of high-resolution ARM studies performed at our institution and identified patients with an absent rectoanal inhibitory reflex (RAIR). Clinical presentation, medical history, treatment outcomes, and results of ARM and other diagnostic tests were collected. We compared data between IASA patients, HD patients, and a matched control group of patients with functional constipation (FC).

KEY RESULTS

We reviewed 1,072 ARMs and identified 109 patients with an absent RAIR, of whom 28 were diagnosed with IASA. Compared to patients with FC, patients with IASA had an earlier onset of symptoms and were more likely to have abnormal contrast enema studies. Compared to patients with HD, patients with IASA were more likely to have had a normal timing of meconium passage, a later onset of symptoms, and were diagnosed at an older age. At the latest follow-up, the majority of patients diagnosed with IASA (54%) were only using oral laxatives. Over half of patients with IASA had been treated with anal sphincter botulinum toxin injection, and 55% reported a positive response.

CONCLUSIONS AND INFERENCES

Patients diagnosed with IASA may represent a more severe patient population compared to patients with FC, but have a later onset of symptoms compared to patients with HD. They may require different treatments for their constipation and deserve further study.

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

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

A piglet model of iatrogenic rectosigmoid hypoganglionosis reveals the impact of the enteric nervous system on gut barrier function and microbiota postnatal development

BACKGROUND

Hirschsprung-associated enterocolitis physiopathology likely involves disturbed interactions between gut microbes and the host during the early neonatal period. Our objective was to create a neonatal porcine model of iatrogenic aganglionosis to evaluate the impact of the enteric nervous system (ENS) on microbiota and intestinal barrier postnatal development.

METHODS

Under general anesthesia, the rectosigmoid serosa of 5-day-old suckling piglets was exposed to 0.5% benzalkonium chloride solution (BAC, n = 7) or saline (SHAM, n = 5) for 1 h. After surgery, animals returned to their home-cage with the sow and littermates and were studied 21 days later.

RESULTS

BAC treatment induced partial aganglionosis with absence of myenteric plexus and reduced surface area of submucosal plexus ganglia (-58%, P < 0.05) in one third of the rectosigmoid circumference. Epithelial permeability of this zone was increased (conductance +63%, FITC-dextran flux +386%, horseradish-peroxidase flux +563%, P < 0.05). Tight junction protein remodeling was observed with decreased ZO-1 (-95%, P < 0.05) and increased claudin-3 and e-cadherin expressions (+197% and 61%, P < 0.05 and P = 0.06, respectively). BAC piglets harbored greater abundance of proinflammatory bacteria (Bilophila, Fusobacterium) compared to SHAM in the rectosigmoid lumen.

CONCLUSIONS

This large animal model demonstrates that hypoganglionosis is associated with dramatic defects of gut barrier function and establishment of proinflammatory bacteria.

Phenotypic spectrum associated with pathogenic mutation in the NRG1 gene in Acadian family

NRG1 is a gene that encodes for a protein that binds to a receptor of the tyrosine kinase family which is essential for the survival of the central nervous system development during embryogenesis. Mutation of the NRG1 gene causes aganglionosis, which leads to Hirschsprung disease. Two brothers of Acadian descent presented with a history of Hirschsprung disease, in association with other anomalies including congenital heart disease, learning difficulties, developmental issues, and hypopigmented hair patch. Molecular analysis in both siblings revealed a heterozygous pathogenic mutation in the NGR1 gene (c.235C>T [p.Arg79*]), that was inherited from an unaffected father. This family expands our knowledge about the phenotypic spectrum associated with pathogenic mutation in the NRG1 gene with intrafamilial variability and the likely reduced penetrance for the phenotypic expression.

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

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

Involvement of the lncRNA AFAP1-AS1/microRNA-195/E2F3 axis in proliferation and migration of enteric neural crest stem cells of Hirschsprung's disease

NEW FINDINGS

What is the central question of this study? Long non-coding RNAs (lncRNAs) are widely involved in the progression of Hirschsprung's disease (HSCR), but the role of actin filament associated protein 1 antisense RNA1 (AFAP1-AS1), an lncRNA, in HSCR has not been explored before. What is the main finding and its importance? Downregulation of AFAP1-AS1 blocks enteric neural crest stem cell proliferation, differentiation, migration and invasion and promotes the occurrence of HSCR via the miR-195/E2F3 axis, indicating thatAFAP1-AS might be a potential biomarker for HSCR patients.

ABSTRACT

Long non-coding RNAs (lncRNAs) are involved in several human disorders. Nevertheless, it remains unclear whether they are implicated in the phenotypes of enteric neural crest stem cells (ENCSCs) in Hirschsprung's disease (HSCR). Therefore, we designed this study to explore the pathogenicity of AFAP1-AS1 for HSCR. Microarray analysis and bioinformatic tools were used to screen out the differentially lncRNAs and microRNAs (miRNAs) in patients with HSCR. Small interference RNA transfection was applied to carry out functional experiments in ENCSCs. Cellular activities were detected by cell counting kit-8, 5-ethynyl-2'-deoxyuridine, Transwell assays and flow cytometry. Finally, rescue experiments were performed to examine the cofunction of AFAP1-AS1 and miR-195 and of miR-195 and E2F transcription factor 3 (E2F3). AFAP1-AS1 was reduced in HSCR patients. Meanwhile, knockdown of AFAP1-AS1 reduced the cell migratory and proliferative capacities and facilitated cell apoptosis along with G0/G1 phase arrest. E2F3 was diminished when miR-195 was upregulated, and AFAP1-AS1 inhibition reduced its ability to bind to miR-195. Altogether, AFAP1-AS1 silencing acts as an endogenous RNA by interacting with miR-195 to alter E2F3 expression, thus conferring repressive effects on ENCSC activity and promoting HSCR progression.

Downregulation of miR-140-5p affects the pathogenesis of HSCR by targeting EGR2

BACKGROUND/AIMS

Hirschsprung's disease (HSCR) is the most common digestive disease caused by disorders of neural crest development. Despite the known involvement of miR-140-5p in many human diseases, its biological role in Hirschsprung's disease (HSCR) remains undefined. In this study, we sought to reveal the roles of miR-140-5p in the pathogenesis of HSCR.

METHODS

Quantitative real-time PCR and western blotting were used to measure the relative expression levels of miRNAs, mRNAs, and proteins in stenotic and dilated sections of the colon of 32 HSCR patients. Targets and proteins were evaluated by western blotting, and Transwell, CCK-8, and flow cytometry assays were adopted to detect the functional effects of miR-140-5p on SH-SY5Y cells.

RESULTS

miR-140-5p was significantly downregulated in HSCR tissue samples with increased expression of EGR2, and knockdown of miR-140-5p inhibited cell migration and proliferation and promoted apoptosis in SH-SY5Y cell lines. EGR2 expression was inversely correlated with that of miR-140-5p in cell lines.

CONCLUSIONS

miR-140-5p may influence the pathogenesis of HSCR by targeting EGR2.

Primary laparoscopic endorectal pull-through procedure with or without a postoperative rectal tube for hirschsprung disease: a multicenter perspective study

BACKGROUND

Hirschsprung-associated enterocolitis (HAEC) is a significant complication of HD both in the pre- and postoperative periods. This was a large multicenter series study to determine the effect of preserving a postoperative rectal tube on preventing HAEC after primary laparoscopic endorectal pull-through procedure.

METHODS

Between 2014 and 2017, a total of 383 consecutive patients with rectosigmoid segment HD were randomly divided into group A (n = 190) and group B (n = 193). All of them underwent primary laparoscopic pull-through procedure, with the same postoperative treatment protocols except for group A with a rectal tube after surgery for 5 days, while group B did not have it. The mean time of follow-up was 2.0 ± 0.53 years (0.5-3.6 years). Demographics, operative data, postoperative complications, and clinical outcomes were compared between these two groups.

RESULTS

Outcomes within 1 month after surgery indicated a lower incidence of abdominal distention (4% vs 15.5%, P < 0.05) and postoperative HAEC (1.2% vs 6.8%, P < 0.05) in group A compared to group B. Beyond 1 month after surgery, the overall incidence of HAEC was not significantly different (12% vs 13.1%, P = 0.54). However, further analysis revealed that the patients who suffered HAEC twice or above twice in group A were significantly less than those in group B (3.6% vs 8.3%, p = 0.02). There were no significant differences in the defecation frequency and other complications.

CONCLUSIONS

Primary laparoscopic endorectal pull-through procedure with a postoperative rectal tube can reduce the early-stage postoperative incidence of abdominal distension and HAEC and the risk of HAEC recurrence in the long term, and is beneficial to postoperative management.

LEVEL OF EVIDENCE

Level 2.

New mutations associated with Hirschsprung disease

INTRODUCTION

Hirschsprung Disease is caused by an impairment in cell migration from the neural crest to the gastrointestinal tract, resulting in an absence of neurons in the myenteric plexus. Many mutations in several genes have been associated to Hirschsprung disease; most of them affecting the RET proto-oncogen pathway. The purpose of this study is the description of novel and known mutations in genes associated to Hirschsprung disease and their prognostic implications.

MATERIAL AND METHODS

Retrospective analysis of patients with Hirschsprung disease and positive genetic studies evaluated from 1970 to 2013.

RESULTS

We found 21 positive genetic studies in the global series, 17 of them involving the RET proto-oncogene: Two of the mutations are novel and they have not been reported in the medical literature.

CONCLUSIONS

The RET protooncogene is the main gene associated with Hirschsprung disease. There are still multiple unknown mutations related to the pathogenesis of the disease. The study of this gene must be part of the work-up of all patients with Hirschsprung disease, as well as their first degree relatives if the mutation is associated with MEN2A and MEN2B syndromes.

[New mutations associated with Hirschsprung disease]

INTRODUCTION

Hirschsprung disease is caused by an impairment in cell migration from the neural crest to the gastrointestinal tract, resulting in an absence of neurons in the myenteric plexus. Many mutations in several genes have been associated to Hirschsprung disease; most of them affecting the RET proto-oncogen pathway. The purpose of this study is the description of novel and known mutations in genes associated to Hirschsprung disease and their prognostic implications.

MATERIAL AND METHODS

Retrospective analysis of patients with Hirschsprung disease and positive genetic studies evaluated from 1970 to 2013.

RESULTS

We found 21 positive genetic studies in the global series, 17 of them involving the RET proto-oncogene. Two of the mutations are novel and they have not been reported in the medical literature.

CONCLUSIONS

The RET protooncogene is the main gene associated with Hirschsprung disease. There are still multiple unknown mutations related to the pathogenesis of the disease. The study of this gene must be part of the work-up of all patients with Hirschsprung disease, as well as their first degree relatives if the mutation is associated with MEN2A and MEN2B syndromes.

Transumbilical enterostomy for Hirschsprung's disease with a two-stage laparoscopy-assisted pull-through procedure

BACKGROUND

A one-stage laparoscopic operation has recently been considered a favorable option for the management of patients with Hirschsprung's disease (HD) due to its superior cosmetic results. One-stage transanal endorectal pull-through for the treatment of rectosigmoid HD has been widely used in newborns without complications. However, enterostomy is required in some HD cases for enterocolitis and dilated colon. Our transumbilical enterostomy (TUE) and two-stage laparoscopy-assisted anorectoplasty were effective and achieved a similar cosmetic effect to one-stage laparoscopy on the abdominal wall in patients with anorectal malformation, but the effect in patients with HD is unclear.

AIM

To evaluate the safety, efficacy and cosmetic results of TUE in two-stage laparoscopy-assisted pull-through for HD.

METHODS

From June 2013 to June 2018, 53 patients (40 boys, 13 girls; mean age at enterostomy: 5.5 ± 2.2 mo) who underwent enterostomy and two-stage laparoscopy-assisted pull-through for HD with stoma closure were reviewed at our institution. Two enterostomy approaches were used: TUE in 24 patients, and conventional abdominal enterostomy (CAE) in 29 patients. Eleven patients with rectosigmoid HD had severe preoperative enterocolitis or a dilated colon. 26 patients had long-segment HD, and 16 patients had total colonic aganglionosis (TCA). The patients with left-sided HD underwent the two-stage laparoscopic Soave procedure, and the patients with right-sided HD and TCA underwent the laparoscopic Duhamel procedure. Demographics, enterostomy operative time, complications and cosmetic results were respectively evaluated.

RESULTS

There were no differences between the groups with respect to gender, age at enterostomy, weight and clinical type (P > 0.05). No conversion to open technique was required. Two patients experienced episodes of stomal mucosal prolapse in the TUE group and 1 patient in the CAE group (8.33% vs 3.45%, P > 0.05). No parastomal hernia was observed in either of the two groups. Wound infection at the stoma was seen in 1 case in the TUE group, and 2 cases in the CAE group (4.17% vs 6.90%, P > 0.05). No obstruction was noted in any of the patients in the TUE group, whereas obstruction was found in 1 patient in the CAE group. Enterocolitis was observed in 3 and 5 patients in the TUE and CAE group, respectively (12.50% vs 17.24%, P > 0.05). There was no significant difference between the TUE group and CAE group in terms of the incidence of soiling and constipation (P > 0.05). The cosmetic result using the scar score in the TUE group was better than that in the CAE group (6.83 ± 0.96 vs 13.32 ± 1.57, P < 0.05).

CONCLUSION

TUE is a safe and feasible method for the treatment of HD, and the staged enterostomy and two-stage laparoscopy-assisted pull-through achieved a similar cosmetic effect to the one-stage laparoscopic procedure.

Functional Studies on Novel RET Mutations and Their Implications for Genetic Counseling for Hirschsprung Disease

Hirschsprung disease (HSCR) is a genetic disorder characterized by the absence of ganglion cells in the gut. RET is considered to be the main susceptibility gene. In our previous screening of 83 HSCR patients, targeted exome sequencing identified nine rare variants of RET, most of which were new discoveries. Here, we performed in vitro arrays with functional studies to investigate their effects. Two variants (p.R77C and p.R67insL) were demonstrated to disrupt the glycosylation of RET and affect its subcellular localization. Three nonsense mutations (p.W85X, p.E252X, and p.Y263X) could not produce detectable RET full-length protein, and the other three mutations (p.R770X, p.Q860X, and p.V778Afs*1) were translated into truncated proteins of predicted sizes. One canonical splice acceptor site mutation (c.2802-2 A > G) was verified to affect gene regulation through aberrant splicing. In addition, we explored the effects of read-through reagents on RET nonsense mutations and showed that G418 significantly increased the full-length RET protein expression of p.Y263X in a dose-dependent manner, together with a mild recovery of p-ERK and p-STAT3. Our data provide a functional analysis of novel RET mutations and suggest that all of the rare variants detected from patients with clinically severe HSCR are indeed pathogenic. Thus, our findings have implications for proper genetic counseling.

Swedish national population-based study shows an increased risk of depression among patients with Hirschsprung disease

AIM

Hirschsprung disease is usually treated during infancy. The long-term impact on mental health has not been well studied. The aim of this study was to assess the risk for depressive disorders in individuals with Hirschsprung disease.

METHODS

This was a nationwide, population-based cohort study. The study exposure was Hirschsprung disease and the study outcome was depression. The exposed cohort included all individuals with Hirschsprung disease, registered in the Swedish National Patient Register between 1964 and 2013 and the unexposed cohort included ten age- and sex-matched controls per patient. The diagnosis of depression was confirmed by diagnosis in the Swedish National Patient Register.

RESULTS

The cohort included 739 (76.5% males) individuals with Hirschsprung disease and 7390 (76.5% males) controls. Among the patients with Hirschsprung disease, 35 (4.7%) of the patients had had a depressive disorder and 187 (2.5%) of controls, hazard ratio 1.98, 95% confidence interval 1.38-2.84. The mean age at diagnosis of first depression was 21.9 years (SD ± 7) in Hirschsprung disease patients and 23.4 years (SD ± 7), p = 0.236 in the unexposed group. There were no significant gender differences.

CONCLUSION

We found an increased risk of having depressive disorders among individuals with Hirschsprung disease compared to controls.

Delay in operation for Hirschsprung Disease is associated with decreased length of stay: a 5-Year NSQIP-Peds analysis

OBJECTIVE

The optimal timing of a pull-through procedure for Hirschsprung Disease is unknown. We, therefore, compared outcomes of pull-throughs performed in the first 30 days of age to 31-120 days.

STUDY DESIGN

Retrospective review of 282 patients in the NSQIP-Peds database from 2012-2016 of infants ≤120-days old and >36-weeks gestational age with Hirschsprung Disease who underwent primary pull-through. Primary outcome was postoperative and total length of stay (LOS). Operative morbidity and readmissions were also compared.

RESULTS

Postoperative LOS in <31-day group was 8.3 days (SD- 8.3) vs. 4.3 days (SD- 5.5) in 31-120-day group (p < 0.001). This finding was maintained on multivariate linear regression. Complication and readmission rates did not differ between groups (readmission: 15.6 vs 13% p = 0.51; complication: 5.5 vs 10% p = 0.16).

CONCLUSION

For appropriately selected patients with Hirschsprung Disease, delaying pull-through until the second month of life is associated with lower total and postoperative stays without increased readmissions or complications.

Expression of BMP-4 and Smad1 in patients with Hirschsprung disease and its clinical significance

Expression and clinical significance of bone morphogenetic protein (BMP)-4 and Smad1 in patients with Hirschsprung disease (HD) were investigated. A retrospective analysis of 96 HD patients (experimental group) admitted to Xuzhou Children's Hospital, Xuzhou Medical University from June 2015 to June 2017 was performed. According to the samples, the experimental group was divided into the stenosis group, the transition group and the expansion group. Forty-seven children with colostomy due to intestinal obstruction were selected as the control group. The expression levels of BMP-4 and Smad1 proteins were detected by immunohistochemical staining. The expression levels of BMP-4 and Smad mRNA were detected by real-time quantitative PCR (RT-qPCR), and were quantified and compared. Via immunohistochemistry, BMP-4 and Smad1 proteins were detected in the samples of different parts of HD patients and children with intestinal obstruction. The positive expression levels of BMP-4 and Smad1 proteins in the transition group were decreased compared with those in the expansion and control groups (P<0.05), and the positive expression levels of BMP-4 and Smad1 proteins in the stenosis group were decreased compared with those in the transition, expansion, and control groups (P<0.05). Also, the gene expression levels of BMP-4 and Smad1 in the transition and stenosis groups were successively decreased, and the differences were statistically significant (P<0.05). In conclusion, the expression of BMP-4 and Smad1 in the intestinal plexus of HD lesions was significantly reduced, indicating that BMP-4 and Smad1 are closely related to the occurrence of HD, and it is suspected that they have a certain influence on the intestinal development of congenital digestive tract malformations.

Gfra1 Underexpression Causes Hirschsprung's Disease and Associated Enterocolitis in Mice

BACKGROUND & AIMS

RET, the receptor for the glial cell line-derived neurotrophic factor (GDNF) family ligands, is the most frequently mutated gene in congenital aganglionic megacolon or Hirschsprung's disease (HSCR). The leading cause of mortality in HSCR is HSCR-associated enterocolitis (HAEC), which is characterized by altered mucin composition, mucin retention, bacterial adhesion to enterocytes, and epithelial damage, although the order of these events is obscure. In mice, loss of GDNF signaling leads to a severely underdeveloped enteric nervous system and neonatally fatal kidney agenesis, thereby precluding the use of these mice for modeling postnatal HSCR and HAEC. Our aim was to generate a postnatally viable mouse model for HSCR/HAEC and analyze HAEC etiology.

METHODS

GDNF family receptor alpha-1 (GFRa1) hypomorphic mice were generated by placing a selectable marker gene in the sixth intron of the Gfra1 locus using gene targeting in mouse embryonic stem cells.

RESULTS

We report that 70%-80% reduction in GDNF co-receptor GFRa1 expression levels in mice results in HSCR and HAEC, leading to death within the first 25 postnatal days. These mice mirror the disease progression and histopathologic findings in children with untreated HSCR/HAEC.

CONCLUSIONS

In GFRa1 hypomorphic mice, HAEC proceeds from goblet cell dysplasia, with abnormal mucin production and retention, to epithelial damage. Microbial enterocyte adherence and tissue invasion are late events and therefore unlikely to be the primary cause of HAEC. These results suggest that goblet cells may be a potential target for preventative treatment and that reduced expression of GFRa1 may contribute to HSCR susceptibility.

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.

Gene expression profiling coupled with Connectivity Map database mining reveals potential therapeutic drugs for Hirschsprung disease

BACKGROUND

Hirschsprung disease (HD) is a congenital intestinal anomaly resulting from a failure to form enteric ganglia in the lower bowel. Surgery is the main therapeutic strategy, although neural stem cell transplantation has recently shown promise. However, HD remains a challenging disorder to treat. Our aim was to identify drugs that could counteract the dysregulated pathways in HD and could thus be potential novel therapies.

METHODS

We used microarray analysis to identify genes differentially expressed in ganglionic and aganglionic bowel samples from eight children with HD. The signature of differentially expressed genes was then used as a search query to explore the Connectivity Map (cMAP), a transcriptional expression database that catalogs gene signatures elicited by chemical perturbagens.

RESULTS

We uncovered several dysregulated signaling pathways, and in particular regulation of neuron development, in HD. The cMAP search identified some compounds with the potential to counteract the effects of the dysregulated molecular signature in this disease. One of these, pepstatin A, was recently shown to rescue the migration defects observed in a mouse model of HD, providing strong support for our findings.

CONCLUSIONS

This study advances our understanding of the molecular changes in HD and identifies several potential pharmacological interventions. Further testing of the identified compounds is warranted.

Predicting sexual problems in young adults with an anorectal malformation or Hirschsprung disease

AIM

The aim of this study was to examine the prevalence of sexual dysfunction and distress and to assess whether sexual functioning could be predicted by psychosocial factors in childhood and adolescence in patients with an anorectal malformation or Hirschsprung disease.

MATERIAL AND METHODS

In 1998 patients completed a psychosocial questionnaire: The Self-Perception profile. To assess the prevalence of sexual distress and sexual functioning in adulthood (2015) the Female Sexual Function Index (FSFI), The Female Sexual Distress Scale (FSDS) and the International Index of Erectile Functioning (IIEF) were used.

RESULTS

In total 74 patients returned the questionnaires (26.2%). 36.8% of women reported sexual dysfunction and 45% experienced sexual distress. In our male sample 8.8% reported mild to moderate erectile dysfunction. In females perceived self-competence in adolescence was associated with sexual distress (p<.01). In male adolescents associations were found between perceived self-competence in romantic relations (p<.01) and in close friendships (p<.05) and sexual desire in adulthood.

CONCLUSION

Pediatric surgeons should be more aware of sexual problems patients may face at older age as a result of their congenital disease and treatment. More standardized care and follow-up are needed. Prognosis study-Level II.

Identification of risk factors for postoperative recurrent Hirschsprung associated enterocolitis

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Ayurvedic management of chronic constipation in Hirschsprung disease - A case study

Hirschsprung disease (HSCR) or congenital intestinal aganglionosis is characterized by complete absence of neuronal ganglion cells from a portion of the intestinal tract, most commonly in the large intestine. The main sign or symptom of HSCR is constipation usually appearing shortly after birth. This constipation is chronic in nature and usually not relieved with laxatives. The present case is of a patient having HSCR which was successfully managed with Ayurvedic treatment. A four year old boy with complaint of severe constipation, abdominal pain, abdominal distension and occasional vomiting was treated with Panchakarma procedures and Ayurvedic oral drugs. The Ayurvedic diagnosis of the case was Pakvasayagata vata. Shashtikashali pinda swedana (sudation with medicated cooked bolus of rice) and Matra basti (enema with medicated oil) with Ashwagandha taila (Ayurvedic medicated oil) was given for first 16 days. From the 2nd month of treatment, Matra basti was administered daily for 3 months in the dose of 25 ml. In 5th and 6th month Matra basti was administered on alternate days in the dose of 25 ml. From the 7th month Matra basti was administered once weekly in the dose of 25 ml. In 14th month Shashtikashali pinda swedana and Erandmooladi yapna basti (medicated enema) was given for 16 days. Eight scales based Medical outcome study (MOS) – 36 item short form - health surveys was periodically assessed for outcome which shows good improvement. Experience of this case showed that HSCR may satisfactory be managed with Ayurvedic treatment.

Aberrant expression of LncRNA-MIR31HG regulates cell migration and proliferation by affecting miR-31 and miR-31* in Hirschsprung's disease

Hirschsprung's disease (HSCR) is a birth defect that causes a failure of the enteric nervous system to cover the distal gut during early embryonic development. Evidence shows that long non-coding RNAs (lncRNA) play important roles in HSCR. The MIR31 host gene (MIR31HG), also known as Loc554202, is a long non-coding RNA (lncRNA), which acts as the host gene of (microRNA) miR-31 and miR-31*. There have been no studies regarding its function in early developmental defects during pregnancy, and its downstream genetic receptors. We report that downregulation of MIR31HG inhibited migration and proliferation in 293T and SH-SY5Y cell lines, by suppressing miR-31 and miR-31*. Moreover, the downregulation of miR-31 and miR-31* enhanced inter-α-trypsin inhibitor heavy chain 5 (ITIH5) and the phosphatidylinositol-4, 5-bisphosphate 3-kinase catalytic gamma subunit (PIK3CG), respectively with reductions of cell migration and proliferation in 293T and SH-SY5Y cell lines. In addition, synergistic actions were observed between miR-31 and miR-31* in cell migration and proliferation. Our results demonstrated that the MIR31HG-miR-31/31*-ITIH5/PIK3CG pathway plays a role in the pathogenesis of HSCR.

Gut feelings: Studying enteric nervous system development, function, and disease in the zebrafish model system

The enteric nervous system (ENS) is the largest part of the peripheral nervous system and is entirely neural crest-derived. It provides the intrinsic innervation of the gut, controlling different aspects of gut function, such as motility. In this review, we will discuss key points of Zebrafish ENS development, genes, and signaling pathways regulating ENS development, as well as contributions of the Zebrafish model system to better understand ENS disorders. During their migration, enteric progenitor cells (EPCs) display a gradient of developmental states based on their proliferative and migratory characteristics, and show spatiotemporal heterogeneity based on gene expression patterns. Many genes and signaling pathways that regulate the migration and proliferation of EPCs have been identified, but later stages of ENS development, especially steps of neuronal and glial differentiation, remain poorly understood. In recent years, Zebrafish have become increasingly important to test candidate genes for ENS disorders (e.g., from genome-wide association studies), to identify environmental influences on ENS development (e.g., through large-scale drug screens), and to investigate the role the gut microbiota play in ENS development and disease. With its unique advantages as a model organism, Zebrafish will continue to contribute to a better understanding of ENS development, function, and disease. Developmental Dynamics 247:268-278, 2018. © 2017 Wiley Periodicals, Inc.

Are all patients with short segment Hirschsprung's disease equal? A retrospective multicenter study

BACKGROUND/PURPOSE

Short segment Hirschsprung's disease (HSCR) carries a better prognosis than long segment disease, but the definition of short is controversial. The objective of this study is to determine anatomically the extent of disease involvement that would be associated with a better functional outcome.

METHODS

This is a retrospective multicenter (n = 3) study with patients (≥ 3 years) who had transanal pullthrough operation done for aganglionosis limited to the recto-sigmoid colon were reviewed. The extent of disease involvement and bowel resection was retrieved by reviewing the operative records as well as histopathological reports of the resected specimens. Clinical assessment was performed according to the criteria of a seven-itemed bowel function score (BFS) (maximum score = 20). Manometric assessment was performed with anorectal manometry.

RESULTS

The study period started from 2003 to 45 patients were studied with median age at assessment = 52.0 months and operation = 3.0 months. The disease involvement was categorized into upper sigmoid-descending colon (DC) (n = 8), sigmoid colon (SC) (n = 12), upper rectum (UR) (n = 14) and lower rectum (LR) (n = 11) according to the level of normal biopsy result. There was no significant difference in the age of assessment between the four groups. The median BFSs in the DC, SC, UR and LR were 13, 15, 17 and 17, respectively (p = 0.01). Nine patients from the DC and SC groups reported soiling for more than twice per week. Sub-group analysis comparing patients with and without the entire sigmoid colon resected revealed worse functional outcomes in terms of the incidence of soiling (40.7 vs 22.2%, p = 0.05) and the BFS (14 vs 18, p = 0.04) in the former group. Anorectal manometry did not reveal any significant difference between the four groups, but a higher proportion of patients in the UR and LR groups appeared to have a normal sphincter resting pressure (DC vs SC vs UR vs LR = 62.5 vs 75.0 vs 85.7 vs 80.0%, p = 0.10).

CONCLUSION

Patients with short segment HSCR are not equal at all. HSCR patients with aganglionosis limited to the rectum without the need of removing the entire sigmoid colon have a better bowel control and overall functional score. Less bowel loss and colonic dissection maybe the underlying reasons. Although future studies with a larger sample size and a longer follow-up period are required to validate the results of this study, it has provided a new insight to the current understanding of short segment disease in HSCR.

Quality of life outcomes in children with Hirschsprung disease

BACKGROUND

Morbidity following repair of Hirschsprung disease (HD) is common. However, quality of life (QoL) results focused on HD children are contradictory. We aimed to measure QoL outcomes in HD children using validated questionnaires.

METHODS

Patients with HD, managed at a large tertiary pediatric institution between 2004 and 2013, were identified. Parents completed validated questionnaires. Results were compared with published healthy population controls. QoL outcomes were measured using Pediatric Quality of Life (PedsQL) and Fecal Incontinence and Constipation Quality of Life (FIC QOL). Functional outcomes were assessed using Baylor Continence Scale, Cleveland Clinic Constipation Scoring System, and Vancouver Dysfunctional Elimination Syndrome Survey.

RESULTS

Parents of 60 HD patients [M:F 49:11; median age 6.4years (2.3-10.9)] were interviewed (59% participation). The majority (47/60, 78%) had rectosigmoid disease. There was significant reduction in psychosocial (social and emotional) QoL compared with healthy children (p=0.03). Psychosocial functioning was affected by increasing age (r=-2.72, p<0.001), fecal incontinence (r=-0.475, p=0.007), constipation (r=-1.58, p=0.006), and dysfunctional elimination (r=-2.94, p=0.004). Fecal incontinence also reduced physical functioning QoL (r=-0.306, p=0.007). Children with HD had significantly higher levels of fecal incontinence (p<0.01).

CONCLUSIONS

We have demonstrated that HD children have significant reductions in psychosocial QoL and functional outcomes.

LEVEL OF EVIDENCE

Prognosis Study - Level II (Prospective cohort study).

Validation of algorithms to determine incidence of Hirschsprung disease in Ontario, Canada: a population-based study using health administrative data

Objective

Incidence rates of Hirschsprung disease (HD) vary by geographical region, yet no recent population-based estimate exists for Canada. The objective of our study was to validate and use health administrative data from Ontario, Canada to describe trends in incidence of HD between 1991 and 2013.

Study design

To identify children with HD we tested algorithms consisting of a combination of diagnostic, procedural, and intervention codes against the reference standard of abstracted clinical charts from a tertiary pediatric hospital. The algorithm with the highest positive predictive value (PPV) that could maintain high sensitivity was applied to health administrative data from April 31, 1991 to March 31, 2014 (fiscal years 1991–2013) to determine annual incidence. Temporal trends were evaluated using Poisson regression, controlling for sex as a covariate.

Results

The selected algorithm was highly sensitive (93.5%) and specific (>99.9%) with excellent predictive abilities (PPV 89.6% and negative predictive value >99.9%). Using the algorithm, a total of 679 patients diagnosed with HD were identified in Ontario between 1991 and 2013. The overall incidence during this time was 2.05 per 10,000 live births (or 1 in 4,868 live births). The incidence did not change significantly over time (odds ratio 0.998, 95% confidence interval 0.983–1.013, p = 0.80).

Conclusion

Ontario health administrative data can be used to accurately identify cases of HD and describe trends in incidence. There has not been a significant change in HD incidence over time in Ontario between 1991 and 2013.

A Nordic multicenter survey of long-term bowel function after transanal endorectal pull-through in 200 patients with rectosigmoid Hirschsprung disease

OBJECTIVE

Transanal endorectal pull-through (ERPT) is the most popular technique to treat Hirschsprung disease (HD). Still, there is limited knowledge on long-term bowel function. This cross-sectional, multicenter study assessed long-term bowel function in a large HD population and examined predictors of poor outcome.

METHODS

Patients older than four years or their parents filled out a validated questionnaire on bowel function. Clinical details were recorded retrospectively from medical records.

RESULTS

73/200 (37%) patients reported absolutely no impaired bowel function, meaning no constipation, fecal accidents, stoma, appendicostomy or need for enemas. Seven (4%) had a stoma, and 33 (17%) used antegrade or rectal colonic enemas. Most disarrangements of fecal control and constipation were significantly less common in older age group, but abnormal defecation frequency and social problems remained unchanged. Syndromic patients (n=31) experienced frequent fecal accidents (46%) more often than nonsyndromic (14%, P<0.001). Having a syndrome (adjusted OR 5.6, 95% CI 2.1-15, P=0.001) or a complete transanal ERPT (adjusted OR 2.4, 95% CI 1.1-5.7, P=0.038) was significantly associated with poor outcome defined as having a stoma, an appendicostomy, daily fecal accidents or need of regular rectal wash outs.

CONCLUSION

A significant number of HD patients experience bowel problems many years after definite surgery. Fecal control was significantly better in older than younger HD patients, but some continued to have considerable bowel problems also as adults. A total transanal ERPT was associated with poorer outcome. Long-term follow-up of HD patients is warranted. Prognosis Study: Level II.

Effects of NRG1 Polymorphisms on Hirschsprung's Disease Susceptibility: A Meta-analysis

Substantial resources have been devoted to evaluate the relationship between NRG1 variants rs7835688 and rs16879552 and Hirschsprung’s Disease (HSCR) but no consistency exists. This meta-analysis aimed to assess the association between the two SNPs and HSCR. PubMed, EMBASE, and Chinese Biological Medicine databases were searched for studies potentially eligible up to March, 2017. The summary odds ratios (ORs) with 95% CIs were calculated from different genetic models. Nine case-control studies (8 for both and 1 for rs16879552 only) involving 1984 HSCR patients and 4220 controls were identified. The combined results showed a significant association between HSCR risk and rs7835688 in all genetic models (per-allele model: OR = 1.66, 95% CI = 1.35–2.05; P = 1.940E-06). Rs16879552 was significantly associated with HSCR in per-allele (OR = 1.50, 95% CI = 1.27–1.76; P = 1.087E-06), additive and recessive model, except for dominant model. Stratified analysis by ethnicity showed that rs7835688 and rs16879552 were only causative for Asians, but not risk locus for Caucasians. Furthermore, pooled data based on segment length indicated that individuals with rs7835688 experienced a significantly higher risk for short-segment HSCR in all genotypes; but rs16879552 was only found to be associated with long-segment HSCR/ total colonic aganglionosis at the allele level.

Laparoscopic Duhamel Procedure with Ex-Anal Rectal Transection for Right-Sided Hirschsprung's Disease

BACKGROUND

Increased defecation frequency and soiling are common complications of surgery for right-sided Hirschsprung's disease (HD). Though the laparoscopic Duhamel procedure is a favorable option in right-sided HD, the conventional laparoscopic technique is time consuming and has complications that are associated with the reservoir. In this study, we described a modified laparoscopic Duhamel technique with ex-anal rectal transection combined with the Deloyer's procedure for right-sided HD.

MATERIALS AND METHODS

Between March 2010 and January 2015, 18 right-sided HD underwent this modified laparoscopic Duhamel procedure (MLDP). The main modifications were to mobilize the colon and to dissect the retrorectal space under laparoscopy, pull out, and transect ex-anally by using a linear stapling device through a transverse incision on posterior wall of the rectum. Seven age-matched patients who underwent a conventional laparoscopic Duhamel procedure (CLDP) between March 2008 and December 2010 were included as the control group. Demographics, surgical procedures, operative data, postoperative complications, and clinical outcomes were compared between these two groups.

RESULTS

Operative time was significantly shorter in the MLDP group (150 minutes versus 195 minutes; P = .03). There was no significant difference in mean timespan to obtain a normal defecation frequency (3.8 months versus 3.6 months), incidence of soiling (11.1% versus 14.3%; P = .34), and constipation (5.6% versus 14.3%; P = .69). Pouchitis were not found in the MLDP group, whereas 2 patients in the CLDP group (28.6%) presented with pouchitis and intractable diarrhea, requiring spur division. The incidence of postoperative enterocolitis was not significantly different in the two groups (11.1% in MLDP versus 14.3% in CLDP; P = .68). All 22 patients had a normal defecation over 4 years of age.

CONCLUSIONS

Laparoscopic Duhamel with ex-anal rectal transection is a simple, easy-to-learn, and effective procedure for right-sided HD. It has low postoperative pouchitis because of a short pouch.

Isolated Ileal Perforation in Infancy: A Lethal Initial Presentation of Hirschsprung's Disease

Arare case of ileal perforation, as a fatal initial presentation of total colonic aganglionosis (TCA) in infancy is reported. A 10-week-old boy, was brought to the emergency department with symptoms of complicated intestinal obstruction. He looked ill, was lethargic, markedly dehydrated and had a severely distended abdomen. An abdominal X-ray revealed multiple air fluid levels seen in a distended small intestine. During exploratory laparotomy the ileum was massively dilated with distal segment perforation. Ileal perforation repair was performed. A totally collapsed microcolon was identified. Biopsies were taken from the high rectum, sigmoid and hepatic flexure. Appendectomy and ileostomy were performed. All biopsies, as well as the appendix, showed absence of ganglion cells. Despite this procedure the patient progressively deteriorated and later died due to sepsis. Ileal perforation in infants is a rare, but potentially fatal initial presentation of TCA. Early detection is essential to prevent life-threatening complications.

A Novel Zebrafish ret Heterozygous Model of Hirschsprung Disease Identifies a Functional Role for mapk10 as a Modifier of Enteric Nervous System Phenotype Severity

Hirschsprung disease (HSCR) is characterized by absence of enteric neurons from the distal colon and severe intestinal dysmotility. To understand the pathophysiology and genetics of HSCR we developed a unique zebrafish model that allows combined genetic, developmental and in vivo physiological studies. We show that ret mutant zebrafish exhibit cellular, physiological and genetic features of HSCR, including absence of intestinal neurons, reduced peristalsis, and varying phenotype expressivity in the heterozygous state. We perform live imaging experiments using a UAS-GAL4 binary genetic system to drive fluorescent protein expression in ENS progenitors. We demonstrate that ENS progenitors migrate at reduced speed in ret heterozygous embryos, without changes in proliferation or survival, establishing this as a principal pathogenic mechanism for distal aganglionosis. We show, using live imaging of actual intestinal movements, that intestinal motility is severely compromised in ret mutants, and partially impaired in ret heterozygous larvae, and establish a clear correlation between neuron position and organised intestinal motility. We exploited the partially penetrant ret heterozygous phenotype as a sensitised background to test the influence of a candidate modifier gene. We generated mapk10 loss-of-function mutants, which show reduced numbers of enteric neurons. Significantly, we show that introduction of mapk10 mutations into ret heterozygotes enhanced the ENS deficit, supporting MAPK10 as a HSCR susceptibility locus. Our studies demonstrate that ret heterozygous zebrafish is a sensitized model, with many significant advantages over existing murine models, to explore the pathophysiology and complex genetics of HSCR.

Hirschsprung Disease (HSCR) is a common congenital intestinal motility disorder diagnosed at birth by absence of enteric neurons in the distal gut, leading to intestinal obstruction that requires life-saving surgery. HSCR exhibits complex inheritance patterns and its genetic basis is not fully understood. Although well studied by human geneticists, and modelled using mouse, significant questions remain about the cellular and genetic causes of the disease and the relationship between neuron loss and defective intestinal motility. Here we use accessible, transparent zebrafish to address these outstanding questions. We establish that ret mutant zebrafish display key features of HSCR, including absence of intestinal neurons, reduced gut motility and varying phenotype expressivity. Using live imaging, possible in zebrafish but not in mouse, we demonstrate that decreased migration speed of enteric neuron progenitors colonising the gut is the principal defect leading to neuron deficits. By direct examination of gut motility in zebrafish larvae, we establish a clear correlation between neurons and motility patterns. Finally, we show that mapk10 mutations worsen the enteric neuron deficit of ret mutants, indicating that mutations in MAPK10 may increase susceptibility to HSCR. We show many benefits of modelling human genetic diseases in zebrafish and advance our understanding of HSCR.

Suppressive action of miRNAs to ARP2/3 complex reduces cell migration and proliferation via RAC isoforms in Hirschsprung disease

Hirschsprung disease (HSCR) is a congenital disorder caused by the defective function of the embryonic enteric neural crest. The impaired migration of embryonic enteric neural crest plays an important role in the pathogenesis of this disease. Recent studies showed that the ARP2/3 complex and RAC isoforms had effects on actin cytoskeleton remodelling, which contributes to migration. Moreover, some regulatory relationships were identified between ARP2/3 complex and RAC isoforms. Although microRNAs (miRNAs) have been known to modulate target gene expression on the post-transcriptional level, little is known about the regulation among miRNAs, ARP2/3 complex and RAC isoforms. Here, we report that down-regulation of ARP2 and ARP3, two main subunits of ARP2/3 complex, suppressed migration and proliferation in 293T and SH-SY5Y cell lines via the inhibition of RAC1 and RAC2. Meanwhile, as the target genes, ARP2 and ARP3 are reduced by increased miR-24-1* and let-7a*, respectively, in 70 HSCR samples as compared with 74 normal controls. Co-immunoprecipitation showed that aberrant reduction in ARP2 and ARP3 could weaken the function of ARP2/3 complex. Our study demonstrates that the miR-24-1*/let-7a*-ARP2/3 complex-RAC isoforms pathway may represent a novel pathogenic mechanism for HSCR.