Weighted gene co-expression network analysis and CIBERSORT screening of key genes related to m6A methylation in Hirschsprung's disease

Hirschsprung's disease (HSCR) is a neural crest disease that results from the failure of enteric neural crest cells (ENCCs) to migrate to the corresponding intestinal segment. The RET gene, which regulates enteric neural crest cell proliferation and migration, is considered one of the main risk factors for HSCR and is commonly used to construct HSCR mouse models. The epigenetic mechanism of m6A modification is involved in HSCR. In this study, we analyzed the GEO database (GSE103070) for differentially expressed genes (DEGs) and focused on m6A-related genes. Comparing the RNA-seq data of Wide Type and RET Null, a total of 326 DEGs were identified, of which 245 genes were associated with m6A. According to the CIBERSORT analysis, the proportion of Memory B-cell in RET Null was significantly higher than that of Wide Type. Venn diagram analysis was used to identify key genes in the selected memory B-cell modules and DEGs associated with m6A. Enrichment analysis showed that seven genes were mainly involved in focal adhesion, HIV infection, actin cytoskeleton organization and regulation of binding. These findings could provide a theoretical basis for molecular mechanism studies of HSCR.

Treatment of postoperative intestinal dysfunction of hirschsprung's disease based on the principle of "anorectal balance"

PURPOSE

Radical surgery is the most effective treatment for Hirschsprung's disease. However, some children still have symptoms of intestinal dysfunction such as constipation, abdominal distension, and recurrent enterocolitis after operation. The purpose of this study was to evaluate treatment outcomes of postoperative intestinal dysfunction in children with Hirschsprung's disease by using the principle of "anorectal balance".

METHODS

The clinical data of postoperative intestinal dysfunction in children with Hirschsprung's disease in the single treatment group from July 2019 to July 2021 were retrospectively analyzed. All the enrolled children underwent botulinum toxin injection (2.5 U/kg); 3 to 6 months later, the injection was performed again; the children who had received more than two botulinum toxin injections underwent the internal sphincter myectomy. Anorectal manometry was performed routinely after operation, and abdominal distension and defecation were recorded.

RESULTS

A total of thirty children with postoperative intestinal dysfunction underwent radical surgery for Hirschsprung's disease were included in this study. Symptoms of constipation, abdominal distension and enterocolitis were improved after botulinum toxin injections in most children compared to before surgery (P < 0.01). After re-injection of botulinum toxin in twelve children, the frequency of defecation increased, the anal resting pressure decreased, and the clinical symptoms were relieved again (P < 0.05). Eleven children underwent internal sphincter myectomy, and the symptoms of constipation, abdominal distension and enterocolitis were significantly improved after the operation (P < 0.01).

CONCLUSION

Botulinum toxin injection and internal sphincter myectomy based on the principle of "anorectal balance" can effectively reduce the resting pressure of the anus and relieve intestinal dysfunction, and have satisfactory clinical effect.

Usefulness of Delayed Films of Contrast Enema for Detecting Hirschsprung's Disease

Background

Contrast enema (CE) in Hirschsprung’s disease (HD) provides a road map to surgeons by ascertaining the transition zone (TZ) and helps in pre-surgical planning. In our institute, we use CE as the initial investigation for HD and carry on till the whole colon is fully distended, followed by a 24-hour abdominal film which is also a part of the international protocol. The main aim of this study was to evaluate the usefulness of this 24-hour delayed film in detecting HD, compare it with gold-standard biopsy results, and to evaluate other imaging features of contrast enema for diagnosis of HD in our tertiary-care hospital in Pakistan. 

Methods

This retrospective study was conducted at the Department of Radiology, Aga Khan University Hospital, Karachi. Records of pediatric patients referred for radiological evaluation of symptoms and signs suspicious of HD during the years 2007-2017 were reviewed. A delayed film was labeled positive if the contrast was not completely evacuated when the residual contrast was present till transverse colon and not beyond. Specificity and sensitivity along with positive and negative predictive values were calculated for each finding according to rectal biopsy, taken as the gold standard.

Results

In all, 82 patients met the inclusion criteria out of 111 cases, as they had both biopsy results and delayed 24-hour films. HD was confirmed using rectal biopsy in 56 (43 patients were males and 13 were females) of 82 cases. The most sensitive radiological finding was the transition zone with a sensitivity of 91.07%. The rectosigmoid index was the second most common finding on contrast enema with a sensitivity and specificity of 91.07% and 83.93%, respectively. In all, 59% patients had a positive delayed 24-hour film and were confirmed with having HD on biopsy. The sensitivity, specificity, and positive predictive value of delay in contrast evacuation after 24 hours in our study was 81.25%, 90.91%, and 97.50% respectively.

Conclusion

Contrast enema examinations along with the 24-hour delayed film with mid transverse colon cut-off are optimal for initially investigating HD in a developing nation, and our results show that it correlates well with biopsy. However, rectal biopsy still remains the gold standard for diagnosis. 

Downregulation of Protein Tyrosine Phosphatase Receptor Type R Accounts for the Progression of Hirschsprung Disease

Hirschsprung disease (HSCR) is a common developmental disorder of the enteric nervous system (ENS). However, the disease mechanisms have not been fully elucidated. To better understand the etiology of HSCR, the role and mechanism of HSCR associated PTPRR (protein tyrosine phosphatase receptor-type R) in the multipotency of ENS progenitors and ENS development were explored. In the present study, the downregulated PTPRR expression in HSCR was reflected by microarray and validated by real-time PCR analyses. Moreover, PTPRR protein was mainly expressed in the cytoplasmic area of primary cultured ENS progenitors (Enteric neural crest cells, ENCCs) and significantly decreased after differentiation induction, which implies the anti-differentiation role in ENCCs. Further study employed an adenovirus transfection system. After genetic modulation, the ENCCs maintained undifferentiated patterns even in GDNF (Glial cell-line derived neurotrophic factor)-mediated directional differentiation, as well as significantly increased EdU positive immunofluorescence in the PTPRR overexpressing group while the development of the ENS was stunted in the PTPRR knockdown fetal gut. Moreover, the expression of ERK1/2 activated by GDNF was significantly decreased as reflected by western-blot or immunofluorescence analyses after genetic modulation in the PTPRR overexpressing group, which suggests the potential mechanism in regulating the MAPK/ERK1/2 pathway. Taken together, These data support the idea that PTPRR may ensure a certain number of neural precursor cells by inhibiting ENCC overt differentiation and maintaining ENCC proliferation, which is considered to be the multipotency of ENCCs, and eventually participate in the development of the ENS, and establish PTPRR protein as negative regulator of MAPK/ERK1/2 signaling cascades in neuronal differentiation and demonstrate their involvement in the pathophysiology of HSCR.

Neonatal Congenital Central Hypoventilation Syndrome: Why We Should not Sleep on it. Literature Review of Forty-two Neonatal Onset Cases

Congenital Central Hypoventilation Syndrome (CCHS), also referred with the expression "Ondine's Curse", is a rare genetic life-long disease resulting from the mutation of PHOX2B gene on chromosome 4p12.3. CCHS represents an autonomic nervous system disorder; its more fearsome manifestation is central hypoventilation, due to a deficient response of chemoreceptors to hypercapnia and hypoxia. Several associated symptoms can occur, such as pupillary anomalies, arrhythmias, reduced heart rate variability, esophageal dysmotility, and structural comorbidities (Hirschsprung's Disease or neural crest tumours). CCHS typical onset is during the neonatal period, but cases of delayed diagnosis have been reported; moreover, both sporadic or familial cases can occur. In preterm newborns, asphyxia and typical prematurity-related findings may overlap CCHS clinical manifestations and make it harder to formulate a correct diagnosis. The early recognition of CCHS allows appropriate management, useful to reduce immediate and long- term consequences.

Characteristics of the Contrast Enema Do Not Predict an Effective Bowel Management Regimen for Patients with Constipation or Fecal Incontinence

Background: A bowel management program using large volume enemas may be required for children with anorectal malformations (ARM), Hirschsprung’s disease (HD), severe medically refractive idiopathic constipation (IC), and other conditions. A pretreatment contrast enema is often obtained. We sought to determine if the contrast enema findings could predict a final enema regimen.

Methods: A retrospective review was performed at a tertiary care children’s hospital from 2011 to 2014 to identify patients treated with enemas in our bowel management program. Patient characteristics, contrast enema findings (including volume to completely fill the colon), and final enema regimen were collected.

Results: Eighty-three patients were identified (37 ARM, 7 HD, 34 IC, and 5 other). Age ranged from 10 months to 24 years, and weight ranged from 6.21 kg to 95.6 kg at the time bowel management was initiated. Linear regression showed contrast enema volume was of limited value in predicting effective therapeutic saline enema volume (R² = 0.21). The addition of diagnosis, colon dilation, and contrast retention on plain x-ray the day after the contrast enema moderately improved the predictive ability of the contrast enema (R² = 0.35). Median final effective enema volume was 22 mL/kg (range: 5 - 48 mL/kg).

Conclusions: We were unable to demonstrate a correlation with contrast enema findings and the effective enema volume. However, no patient required a daily enema volume greater than 48 mL/kg to stay clean.

Hirschsprung's associated enterocolitis

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Effect of colon transection on spontaneous and meal-induced high-amplitude--propagating contractions in children

BACKGROUND

After Hirschsprung disease (HD) surgery, many children experience fecal incontinence caused by increased number of high-amplitude-propagating contractions (HAPCs) through the neorectum to the anal verge. The aim of this study was to determine whether children with HD have more HAPCs than children with colon transections for reasons other than HD.

METHODS

We reviewed 500 colon manometries. Children (age 7.6 ± 5.1 years, 275 boys) with functional constipation (n = 237, age 7.4 ± 5.0 years, 126 boys) and chronic abdominal pain (n = 48, age 9.8 ± 5.8 years, 25 boys) served as controls compared with subjects with HD (n = 56, age 6.9 ± 4.1 years, 44 boys) and colon transection for other reasons (n = 24, age 6.1 ± 5.8 years, 12 boys). We excluded 139 subjects without HAPCs. We documented HAPCs during 1-hour fasting and 1-hour postprandial. Results are in mean ± SD.

RESULTS

During fasting, HD subjects had more HAPCs (2.2 ± 3.4/hour) versus functional constipation (0.8 ± 2.2/hour, P = 0.0004) and chronic pain (0.5 ± 1.1/hour, P = 0.001), but not more than colon transection (1.9 ± 3.2/hour, P = 1.0). HD showed more postprandial HAPCs (4.0 ± 5.4/hour) than functional constipation (1.5 ± 2.5/hour, P < 0.0001) and chronic pain (0.9 ± 1.6/hour, P < 0.0001), but not more than colon transection (2.4 ± 3.0/hour, P = 0.6). There were more HAPCs fasting and postprandial after colon transection (1.9 ± 3.2/hour and 2.4 ± 3.0/hour) than functional constipation (0.8 ± 2.2/hour, P = 0.3 and 1.5 ± 2.5/hour, P = 1.0) and chronic pain (0.5 ± 1.1/hour, P = 1.0 and 0.9 ± 1.6, P = 1.0). HD subjects were divided by chief complaint: fecal incontinence or constipation. HD subjects with incontinence (n = 23) only had more HAPCs fasting (P = 0.01) and postprandial (P = 0.01) than HD subjects with constipation (n = 28) only.

CONCLUSIONS

Increased HAPCs followed colon transection, regardless of a cause. HD subjects with incontinence had more HAPCs than subjects with colon transection for other reasons.

Nestin-expressing cells in the gut give rise to enteric neurons and glial cells

BACKGROUND

Neuronal stem cells (NSCs) are promising for neurointestinal disease therapy. Although NSCs have been isolated from intestinal musclularis, their presence in mucosa has not been well described. Mucosa-derived NSCs are accessible endoscopically and could be used autologously. Brain-derived Nestin-positive NSCs are important in endogenous repair and plasticity. The aim was to isolate and characterize mucosa-derived NSCs, determine their relationship to Nestin-expressing cells and to demonstrate their capacity to produce neuroglial networks in vitro and in vivo.

METHODS

Neurospheres were generated from periventricular brain, colonic muscularis (Musc), and mucosa-submucosa (MSM) of mice expressing green fluorescent protein (GFP) controlled by the Nestin promoter (Nestin-GFP). Neuronal stem cells were also grown as adherent colonies from intestinal mucosal organoids. Their differentiation potential was assessed using immunohistochemistry using glial and neuronal markers. Brain and gut-derived neurospheres were transplanted into explants of chick embryonic aneural hindgut to determine their fate.

KEY RESULTS

Musc- and MSM-derived neurospheres expressed Nestin and gave rise to cells of neuronal, glial, and mesenchymal lineage. Although Nestin expression in tissue was mostly limited to glia co-labelled with glial fibrillary acid protein (GFAP), neurosphere-derived neurons and glia both expressed Nestin in vitro, suggesting that Nestin+/GFAP+ glial cells may give rise to new neurons. Moreover, following transplantation into aneural colon, brain- and gut-derived NSCs were able to differentiate into neurons.

CONCLUSIONS & INFERENCES

Nestin-expressing intestinal NSCs cells give rise to neurospheres, differentiate into neuronal, glial, and mesenchymal lineages in vitro, generate neurons in vivo and can be isolated from mucosa. Further studies are needed for exploring their potential for treating neuropathies.

Full-field optical coherence microscopy is a novel technique for imaging enteric ganglia in the gastrointestinal tract

BACKGROUND

Noninvasive methods are needed to improve the diagnosis of enteric neuropathies. Full-field optical coherence microscopy (FFOCM) is a novel optical microscopy modality that can acquire 1 μm resolution images of tissue. The objective of this research was to demonstrate FFOCM imaging for the characterization of the enteric nervous system (ENS).

METHODS

Normal mice and EdnrB(-/-) mice, a model of Hirschsprung's disease (HD), were imaged in three-dimensions ex vivo using FFOCM through the entire thickness and length of the gut. Quantitative analysis of myenteric ganglia was performed on FFOCM images obtained from whole-mount tissues and compared with immunohistochemistry imaged by confocal microscopy.

KEY RESULTS

Full-field optical coherence microscopy enabled visualization of the full thickness gut wall from serosa to mucosa. Images of the myenteric plexus were successfully acquired from the stomach, duodenum, colon, and rectum. Quantification of ganglionic neuronal counts on FFOCM images revealed strong interobserver agreement and identical values to those obtained by immunofluorescence microscopy. In EdnrB(-/-) mice, FFOCM analysis revealed a significant decrease in ganglia density along the colorectum and a significantly lower density of ganglia in all colorectal segments compared with normal mice.

CONCLUSIONS & INFERENCES

Full-field optical coherence microscopy enables optical microscopic imaging of the ENS within the bowel wall along the entire intestine. FFOCM is able to differentiate ganglionic from aganglionic colon in a mouse model of HD, and can provide quantitative assessment of ganglionic density. With further refinements that enable bowel wall imaging in vivo, this technology has the potential to revolutionize the characterization of the ENS and the diagnosis of enteric neuropathies.

Total colonic aganglionosis: a surgical challenge. How to avoid complications?

INTRODUCTION

Total colonic aganglionosis represents a significant challenge for pediatric surgeons. Long-term results are suboptimal and complications are very common. We analyzed our experience to formulate recommendations to achieve better results and avoid complications and sequelae.

METHODS

The medical records of patients with total colonic aganglionosis that were operated on by us primarily or secondarily were reviewed. We evaluated: number of operations performed, preventable complications, bowel control or presence of stomas, and clinical follow-up. Based on this experience we describe our current approach for this condition. IRB approval was obtained.

RESULTS

27 patients were identified (19 males, 8 females). 12 patients had the primary pullthrough performed by us and 15 were operated on elsewhere before coming to us for reoperation. The average number of operations per patient was 6.8 (1-40). We identified several preventable complications: ileostomy prolapse or stricture (21), severe diaper rash (10), obstructive symptoms following a pouch or patch-type of pullthrough (9), infection, abscess, and fistula after the pullthrough (5); wrong histologic diagnosis leading to colostomy opening in aganglionic bowel (4) with consequent pullthrough of aganglionic intestine in two of them; anastomotic stricture/acquired atresia (3); and destroyed anal canal and permanent fecal incontinence (2). 15 patients have bowel control; 11 have an ileostomy: temporary (7) and permanent (4); and one is less than 3 years of age. Length of follow-up ranged from 1 to 17 years. Based on this experience, our approach for this condition consists of: colectomy with straight ileoanal anastomosis and ileostomy at presentation, followed by ileostomy closure only when the child is toilet trained for urine and is willing to tolerate rectal irrigations.

CONCLUSION

Total colonic aganglionosis remains a serious surgical challenge. Patients suffering from the condition, have multiple complications, sequelae, and often require reoperations. We found that it is possible to prevent many of these by properly fixing the stoma, avoiding pouch or patch procedures, delaying ileostomy closure, having pathology expertise, and with meticulous surgical technique starting the dissection/anastomosis well above the dentate line.

Is the Rehbein procedure obsolete in the treatment of Hirschsprung's disease?

PURPOSE

After 25 years of practice and positive results of the Rehbein-procedure (RB) for children with Hirschsprung Disease (HD), we changed to the less invasive transanal endorectal pull through (TERPT). The aim of this study was to compare short- and mid-term complications of these two procedures in our patients with HD.

METHODS

Retrospective data of 50 HD patients were analyzed. Of these patients, 25 underwent RB (2000-2006) and in 25 the TERPT was performed (2005-2009). Medical records were reviewed to score complications and outcomes. Differences were analyzed using Chi-Square and Mann-Whitney U tests.

RESULTS

All RB patients (100%) were given a colostomy compared with four patients (16%) in the TERPT group (p < 0.001). The average age at surgery in the RB group was 191 days whereas this was 72 days in the TERPT group (p < 0.01). The mean length of time of surgery in the RB group (158 min) was not significantly different from that in the TERPT group (183 min). Ganglion cells were located in all specimens at the proximal end of the specimens. The median time to first feeding significantly decreased from 2 days (range 1-11) in the RB group to 1 day (range 1-3) in the TERPT group (p < 0.01). The median length of hospital stay decreased in the TERPT group (8 days) compared with the RB group (10 days) (p < 0.001). There was a significant reduction in postoperative obstructive symptoms during the first 6 months in the TERPT group (48%) compared with the RB group (84%) (p = 0.016). Postoperative enterocolitis decreased from 40% in the RB group to 24% in the TERPT group although this was not statistically significant.

CONCLUSIONS

The introduction of TERPT reduced the need for colostomies; it shortened days to first feeding after surgery and reduced hospital stay. It also improved short-term outcome with less obstructive symptoms. We recommend TERPT surgery as a first choice in children with HD. we consider the RB now to be obsolete.

Murine model of Hirschsprung-associated enterocolitis. I: phenotypic characterization with development of a histopathologic grading system

PURPOSE

The aim of the study was to characterize enterocolitis in the Ednrb-null (Ednrb-/-) mouse with aganglionosis of the colon and to develop and validate a semiquantitative histopathologic grading system to assess enterocolitis.

METHODS

We isolated colon and ileal specimens of Ednrb-/- and control mice (Ednrb+/+) and performed histochemical staining (H&E) on tissue sections. After establishing inflammation grading criteria, 2 blinded pathologists independently assessed the severity and depth of inflammation of proximal colon segments on 2 separate occasions. Interclass correlations (ICCs) and coefficient of variation (CV) were calculated to determine interrater and intrarater agreement. We then prospectively applied the enterocolitis grading system to Ednrb-/- mice that became clinically ill. A cohort of Ednrb-/- mice were observed until they developed clinical illness, at which time they were euthanized and had multiple organ homogenates cultured for bacteria, and colon and small bowel were histopathologically graded for enterocolitis. Spearman's rank correlations comparing enterocolitis scores with level of bacteremia were performed.

RESULTS

Intra- and interrater ICCs of the histologic scoring system were satisfactory (0.61 and 0.94, respectively), as were intra- and interrater CVs (18% and 9%, respectively). Of the Ednrb-/- mice, 65% developed bacteremia. Those with bacteremia had significantly higher enterocolitis scores than those without bacteremia (P < .01). Ednrb-/- mice that developed bacteremia showed a strong positive correlation between total enterocolitis scores and number of bacterial colony forming units in peritoneal lavage, liver, kidney, and aerobic spleen.

CONCLUSIONS

The Ednrb-/- mouse with aganglionosis develops enterocolitis and has features similar to Hirschsprung-associated enterocolitis in humans. Our grading system is a reliable way to assess enterocolitis. By performing microsurgical pull-through, we can now perform controlled, hypothesis-driven, mechanistic studies to evaluate etiologic factors affecting enterocolitis in the Ednrb-/- mouse.

Development of enteric neuron diversity

The mature enteric nervous system (ENS) is composed of many different neuron subtypes and enteric glia, which all arise from the neural crest. How this diversity is generated from neural crest-derived cells is a central question in neurogastroenterology, as defects in these processes are likely to underlie some paediatric motility disorders. Here we review the developmental appearance (the earliest age at which expression of specific markers can be localized) and birthdates (the age at which precursors exit the cell cycle) of different enteric neuron subtypes, and their projections to some targets. We then focus on what is known about the mechanisms underlying the generation of enteric neuron diversity and axon pathfinding. Finally, we review the development of the ENS in humans and the etiologies of a number of paediatric motility disorders.

A novel corrective pullthrough surgery in a mouse model of Hirschsprung's disease

BACKGROUND/PURPOSE

The study aimed to develop a mouse model of post-pullthrough Hirschsprung's disease that will allow investigation of mechanisms that cause postoperative complications.

METHODS

We developed a novel microsurgical pullthrough operation on Balb/C mice and evaluated its effect on growth rate and stooling pattern. Histologic assessment of the pullthrough colon was performed. The pullthrough operation was then performed on Ednrb-/- mice that have aganglionic megacolon and Ednrb+/+ littermate controls, and the outcomes compared.

RESULTS

The Balb/C pullthrough group had 97% survival at 1 week and 70% survival at 2 weeks. Body weight of the pullthrough animals declined 15% in the first week after surgery and subsequently normalized. The stooling pattern showed consistently softer stools in the pullthrough group, but no difference in frequency compared to controls. Histopathologic analyses 4 weeks postoperatively showed well-healed coloanal anastomoses. Two-week survival after pullthrough surgery in Ednrb-/- and Ednrb+/+ mice was 50.0%, and 69.2%, respectively (P = NS). Increased mortality in the Ednrb-/- mice was related to the technical challenge of performing microsurgery on smaller-sized mice with poor baseline health status.

CONCLUSIONS

Our microsurgical pullthrough operation in mice is feasible and allows systematic investigations into potential mechanisms mediating post-pullthrough complications and poor long-term results in mouse models of Hirschsprung's disease.

A bird's eye view of enteric nervous system development: lessons from the avian embryo

The avian embryo has been an important model system for studying enteric nervous system (ENS) development for over 50 y. Since the initial demonstration in chick embryos that the ENS is derived from the neural crest, investigators have used the avian model to reveal the cellular origins and migratory pathways of enteric neural crest-derived cells, with more recent work focusing on the molecular mechanisms regulating ENS development. Seminal contributions have been made in this field by researchers who have taken advantage of the strengths of the avian model system. These strengths include in vivo accessibility throughout development, ability to generate quail-chick chimeras, and the capacity to modulate gene expression in vivo in a spatially and temporally targeted manner. The recent availability of the chicken genome further enhances this model system, allowing investigators to combine classic embryologic methods with current genetic techniques. The strengths and versatility of the avian embryo continue to make it a valuable experimental system for studying the development of the ENS.

Current significance of meconium plug syndrome

BACKGROUND

The significance of meconium plug syndrome is dependent on the underlying diagnosis. The incidence of pathologic finding, particularly Hirschsprung's disease, contributing to the presence of these plugs, has been debated. However, there are little recent data in the literature. Therefore, we reviewed our experience with meconium plugs as a cause of abdominal distension to evaluate the associated conditions and incidence of Hirschsprung's disease.

METHODS

We reviewed the records of newborns with meconium plugs found in the distal colon on contrast enema from 1994 to 2007. Demographics, radiologic findings, histologic findings, operative findings, and clinical courses were reviewed.

RESULTS

During the study period, 77 patients were identified. Mean gestational age was 37.4 weeks and birth weight, 2977 g. Hirschsprung's disease was found in 10 patients (13%). One had ultrashort segment disease and another had total colonic aganglionosis. Maternal diabetes was identified in 6 patients. No patients were diagnosed with cystic fibrosis, meconium ileus, malrotation, or intestinal atresia.

CONCLUSION

Meconium plugs found on contrast enema are associated with a 13% incidence of Hirschsprung's disease in our experience. Although all patients with plugs and persistent abnormal stooling patterns should prompt a rectal biopsy and genetic probe, the incidence of Hirschsprung's and cystic fibrosis may not be as high as previously reported.