Hirschsprung-associated enterocolitis: pathogenesis, treatment and prevention

Laparoscopic-Assisted Colonic Derotation in Patients With Hirschsprung Disease

BACKGROUND

Children with Hirschsprung disease (HSCR) proximal to the splenic flexure or those needing a redo pull-through (PT) are at risk for tension and ischemia of the PT which could result in leak, stricture, or loss of ganglionated bowel. Colonic derotation is a technique used to minimize tension and avoid duodenal obstruction. The aim of this study was to describe this technique and outcomes in a series of patients requiring this intervention.

METHODS

All patients underwent initial diversion and colonic mapping. The derotation procedure involves mobilization of the remaining colon, counterclockwise rotation via the stoma closure site, placement of the pull through (the right colon) lying on the right of the pelvis, and ligation of the middle colic artery with preservation of the marginal branch running from the ileocolic artery. This maneuver prevents compression of the duodenum by the mesenteric vessels and allows for an isoperistaltic, tension-free anastomosis. Intraoperative indocyanine green fluorescence angiography (ICG-FA) was utilized in many of the cases to map the blood supply of the pull-through colon. We reviewed outcomes for all children with HSCR who underwent colonic derotation from 2014 to 2023. Descriptive statistics were performed.

RESULTS

There were 37 children included. Most were male (67.5%) with the original transition zone proximal to the rectosigmoid (81.1%). The median age at PT was 9.3 months [6.1-39.7]. Median operative time was 6.6 h [4.9-7.4] and 19 cases (51.4%) used ICG-FA. Most children had no 30-day postoperative complications (67.6%); in those who did develop complications, readmissions for electrolyte imbalance was most common (50.0%). There were zero cases of anastomotic leak at PT anastomosis. At long-term follow up, median 4.4 years [2.3-7.0], three children (8.1%) developed an anastomotic stricture, all were amenable to anal dilation, and five experienced episodes of enterocolitis (14.7%). Most children had between 1 and 4 stools per day (58.8%).

CONCLUSION

Colonic derotation is a useful strategy to ensure well-perfused colonic length, protect the marginal artery blood supply, avoid duodenal compression, and ensure a tension-free anastomosis with minimal complications.

TYPE OF STUDY

Original research, retrospective cohort.

LEVEL OF EVIDENCE

III.

Development of Prediction Model for Hirschsprung-Associated Enterocolitis (HAEC) in Postoperative Hirschsprung Patients

BACKGROUND

Despite identifying numerous risk factors for postoperative Hirschsprung-associated enterocolitis (HAEC), predicting individual risk remains challenging. This study aimed to develop a clinical prediction model for predicting the probability of postoperative HAEC within 5 years after surgery in Hirschsprung individuals.

METHODS

The study included all children with Hirschsprung disease who underwent definitive surgery at Chiang Mai University Hospital from 2006 to 2021. Concomitant anorectal abnormalities and incomplete data were excluded. A multivariable logistic regression analysis, adjusted for correlated data, was utilized to develop the prediction model.

RESULTS

Of the included 274 patients, 75 patients (27.4%) experienced postoperative HAEC within 5 years, totaling 121 episodes. Based on statistical and theoretical significance, eight parameters were utilized as predictors, which included male (OR1.23,95%CI:0.53-2.86), trisomy21(OR1.34,95%CI:0.21-8.45), weight at the time of surgery (OR0.86,95%CI:0.73-1.02), absence of exclusive breastfeeding (OR1.51,95%CI:0.65-3.51), length of the aganglionic segment (rectosigmoid (OR1.32,95%CI:0.48-3.62), long segment (OR41.39,95%CI:3.00-570.37), and total colonic aganglionosis (OR710.20,95%CI:23.55-21420.72)), preoperative stoma (OR1.72,95%CI:0.34-8.58), surgical approach (Duhamel (OR0.06,95%CI:0.01-0.81) and abdominal assisted trans anal endorectal pull-through (OR0.04,95%CI:0.002-0.65)), and early HAEC before two weeks following surgery (OR1.98,95%CI:0.67-5.82). The derived predictive model exhibited acceptable discriminative performance (AuROC:0.749,95%CI:0.679-0.816). Risk groups were categorized into low and high-risk, with positive likelihood ratios of 0.65 and 10.70, respectively. Recommendations for management and follow-up were generated based on these risk groups. An online application has been developed for calculating individual risk of postoperative HAEC and offering management suggestions with follow-up schedule: [https://w1.med.cmu.ac.th/surgery/personnel/pedsurgerycmu/#HAEC-Calculator].

CONCLUSIONS

This risk predictive model accurately estimates the probability of postoperative HAEC within 5 years after surgery in Hirschsprung patients. It facilitates risk stratification and provides personalized recommendations to parents for the prevention and early detection of postoperative HAEC.

LEVELS OF EVIDENCE

Level II Retrospective cohort study (Prognosis study).

Evaluation and Management of Total Colonic Hirschsprung Disease: A Comprehensive Review From the American Pediatric Surgical Association (APSA) Hirschsprung Disease Interest Group

BACKGROUND

Children with total colonic Hirschsprung disease (TCHD) are a unique group of patients with pre- and postoperative management challenges. This review provides a rational, expert-based approach to diagnosing and managing TCHD.

METHODS

The guidelines were developed by the Hirschsprung Disease Interest Group members established by the American Pediatric Surgical Association (APSA) Board of Governors. Group discussions, literature review, and expert consensus were used to summarize the current knowledge regarding diagnosis, staged approach, the timing of pull-through, and pre-and postoperative management in children with TCHD.

RESULTS

This paper presents recommendations for managing TCHD before and after reconstruction, including diagnostic criteria, surgical approaches, bowel management, diet, antibiotic prophylaxis, colonic irrigations, and post-surgical considerations.

CONCLUSIONS

A clear understanding of the unique challenges posed by TCHD and consensus on its treatment are lacking in the literature. This review standardizes this patient group's pre- and postoperative management.

LEVEL OF EVIDENCE

V.

Approach to Constipation in Children: Recommendations for Evaluation and Management

Constipation is common in childhood, and most patients can be successfully managed by their primary care provider. However, some patients will require more specialized management either due to an underlying congenital colorectal disorder such as Hirschsprung disease or anorectal malformation or due to severe functional constipation that is refractory to medical management.

Enteric neural stem cell transplant restores gut motility in mice with Hirschsprung disease

The goal of this study was to determine if transplantation of enteric neural stem cells (ENSCs) can rescue the enteric nervous system, restore gut motility, reduce colonic inflammation, and improve survival in the Ednrb-KO mouse model of Hirschsprung disease (HSCR). ENSCs were isolated from mouse intestine, expanded to form neurospheres, and microinjected into the colons of recipient Ednrb-KO mice. Transplanted ENSCs were identified in recipient colons as cell clusters in "neo-ganglia." Immunohistochemical evaluation demonstrated extensive cell migration away from the sites of cell delivery and across the muscle layers. Electrical field stimulation and optogenetics showed significantly enhanced contractile activity of aganglionic colonic smooth muscle following ENSC transplantation and confirmed functional neuromuscular integration of the transplanted ENSC-derived neurons. ENSC injection also partially restored the colonic migrating motor complex. Histological examination revealed a significant reduction in inflammation in ENSC-transplanted aganglionic recipient colon compared with that of sham-operated mice. Interestingly, mice that received cell transplant also had prolonged survival compared with controls. This study demonstrates that ENSC transplantation can improve outcomes in HSCR by restoring gut motility and reducing the severity of Hirschsprung-associated enterocolitis, the leading cause of death in human HSCR.

Rates of Hirschsprung-Associated Enterocolitis Decrease With Increasing Child Opportunity Index

BACKGROUND

Hirschsprung-associated enterocolitis (HAEC) is the most common cause of morbidity and mortality in patients with Hirschsprung disease (HD). There is a correlation between social determinants of health (SDOH) and outcomes in children with HD. The Child Opportunity Index (COI) is a publicly available dataset that stratifies patients by address into levels of opportunity. We aimed to understand if a relationship exists between COI and HAEC.

METHODS

A single-institution, IRB-approved, retrospective cohort study was performed of children with HD. Census tract information was used to obtain COI scores, which were stratified into categories (very low, low, medium, high, very high). Subgroups with and without history of HAEC were compared.

RESULTS

The cohort had 100 patients, of which 93 had a COI score. There were 27 patients (29.0%) with HAEC. There were no differences in demographics or clinical factors, including length of aganglionic colon, operative approach, and age at pull-through. As child opportunity score increased from very low to very high, there was a statistically significant decrease in the incidence of HAEC (p = 0.04).

CONCLUSION

We demonstrate a significant association between increasing opportunity and decreasing incidence of HAEC. This suggests an opportunity for targeted intervention in populations with low opportunity.

LEVEL OF EVIDENCE

III.

IRB NUMBER

IRB14-00232.

Prognostic factors for persistent obstructive symptoms in patients with Hirschsprung disease following pull-through

BACKGROUND

Although most patients with Hirschsprung disease (HSCR) improve after pull-through, some patients still have persistent obstructive symptoms. Most previous studies reported persistent obstructive symptoms after pull-through in HSCR patients from developed countries. Our study determined the prognostic factors of persistent obstructive symptoms in patients with HSCR following pull-through from a particular developing country.

METHODS

A cross-sectional study was conducted using medical records of patients with HSCR at our institution from January 2017 to January 2022.

RESULTS

We ascertained 114 patients with HSCR: 79 males and 35 females. Most of them (90.4%) showed a short aganglionosis and underwent transanal endorectal pull-through (55.3%). Twenty-two percent of patients showed persistent obstructive symptoms following pull-through. Operative technique and age at definitive surgery were significantly associated with the persistent obstructive symptoms after pull-through (p = 0.011 and 0.019, respectively), while sex, aganglionic segment length, presence of global developmental delay, and Down syndrome were not (p = 0.873, 0.525, 0.647, and 0.301, respectively). Multivariate analysis revealed that age at pull-through was a significant independent factor for persistent obstructive symptoms after pull-through, with an odds ratio of 3.41 (95% CI = 1.18-9.91; p = 0.02).

CONCLUSIONS

Our study shows a moderate frequency of persistent obstructive symptoms after pull-through in our institution. In addition, patients who underwent pull-throughs at a younger age might have persistent obstructive symptoms following a definitive surgery. Our study provides new data on persistent obstructive symptoms after pull-through from a particular population that might be beneficial for pediatric surgeons' consideration before performing definitive surgery on patients with HSCR.

The Prevalence and Clinical Impact of Transition Zone Anastomosis in Hirschsprung Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Hirschsprung disease (HD) is characterized by absent neuronal innervation of the distal colonic bowel wall and is surgically treated by removing the affected bowel segment via pull-through surgery (PT). Incomplete removal of the affected segment is called transition zone anastomosis (TZA). The current systematic review aims to provide a comprehensive overview of the prevalence and clinical impact of TZA.

METHODS

Pubmed, Embase, Cinahl, and Web of Sciences were searched (last search: October 2020), and studies describing histopathological examination for TZA in patients with HD were included. Data were synthesized into aggregated Event Rates (ER) of TZA using random-effects meta-analysis. The clinical impact was defined in terms of obstructive defecation problems, enterocolitis, soiling, incontinence, and the need for additional surgical procedures. The quality of studies was assessed using the Newcastle-Ottawa Scale.

KEY RESULTS

This systematic review included 34 studies, representing 2207 patients. After excluding series composed of only patients undergoing redo PT, the prevalence was 9% (ER = 0.09, 95% CI = 0.05-0.14, p < 0.001, I2 = 86%). TZA occurred more often after operation techniques other than Duhamel (X2 = 19.21, p = <0.001). Patients with TZA often had obstructive defecation problems (62%), enterocolitis (38%), soiling (28%), and fecal incontinence (24%) in follow-up periods ranging from 6 months to 13 years. Patients with TZA more often had persistent obstructive symptoms (X2 = 7.26, p = 0.007).

CONCLUSIONS AND INFERENCES

TZA is associated with obstructive defecation problems and redo PT and is thus necessary to prevent.

State of the Art Bowel Management for Pediatric Colorectal Problems: Hirschsprung Disease

After an initial pull-though, patients with Hirschsprung disease (HD) can present with obstructive symptoms, Hirschsprung-associated enterocolitis (HAEC), failure to thrive, or fecal soiling. This current review focuses on algorithms for evaluation and treatment in children with HD as a part of a manuscript series on updates in bowel management. In constipated patients, anatomic causes of obstruction should be excluded. Once anatomy is confirmed to be normal, laxatives, fiber, osmotic laxatives, or mechanical management can be utilized. Botulinum toxin injections are performed in all patients with HD before age five because of the nonrelaxing sphincters that they learn to overcome with increased age. Children with a patulous anus due to iatrogenic damage of the anal sphincters are offered sphincter reconstruction. Hypermotility is managed with antidiarrheals and small-volume enemas. Family education is crucial for the early detection of HAEC and for performing at-home rectal irrigations.

Risk factors for Hirschsprung disease-associated enterocolitis: a systematic review and meta-analysis

BACKGROUND

The incidence of Hirschsprung disease (HSCR) is nearly 1/5000 and patients with HSCR are usually treated through surgical intervention. Hirschsprung disease-associated enterocolitis (HAEC) is a complication of HSCR with the highest morbidity and mortality in patients. The evidence on the risk factors for HAEC remains inconclusive to date.

METHODS

Four English databases and four Chinese databases were searched for relevant studies published until May 2022. The search retrieved 53 relevant studies. The retrieved studies were scored on the Newcastle-Ottawa Scale by three researchers. Revman 5.4 software was employed for data synthesis and analysis. Stata 16 software was employed for sensitivity analysis and bias analysis.

RESULTS

A total of 53 articles were retrieved from the database search, which included 10 012 cases of HSCR and 2310 cases of HAEC. The systematic analysis revealed anastomotic stenosis or fistula [ I2 =66%, risk ratio (RR)=1.90, 95% CI 1.34-2.68, P <0.001], preoperative enterocolitis ( I2 =55%, RR=2.07, 95% CI 1.71-2.51, P <0.001), preoperative malnutrition ( I2 =0%, RR=1.96, 95% CI 1.52-2.53, P <0.001), preoperative respiratory infection or pneumonia ( I2 =0%, RR=2.37, 95% CI 1.91-2.93, P <0.001), postoperative ileus ( I2 =17%, RR=2.41, 95% CI 2.02-2.87, P <0.001), length of ganglionless segment greater than 30 cm ( I2 =0%, RR=3.64, 95% CI 2.43-5.48, P <0.001), preoperative hypoproteinemia ( I2 =0%, RR=1.91, 95% CI 1.44-2.54, P <0.001), and Down syndrome ( I2 =29%, RR=1.65, 95% CI 1.32-2.07, P <0.001) as the risk factors for postoperative HAEC. Short-segment HSCR ( I2 =46%, RR=0.62, 95% CI 0.54-0.71, P <0.001) and transanal operation ( I2 =78%, RR=0.56, 95% CI 0.33-0.96, P =0.03) were revealed as the protective factors against postoperative HAEC. Preoperative malnutrition ( I2 =35 % , RR=5.33, 95% CI 2.68-10.60, P <0.001), preoperative hypoproteinemia ( I2 =20%, RR=4.17, 95% CI 1.91-9.12, P <0.001), preoperative enterocolitis ( I2 =45%, RR=3.51, 95% CI 2.54-4.84, P <0.001), and preoperative respiratory infection or pneumonia ( I2 =0%, RR=7.20, 95% CI 4.00-12.94, P <0.001) were revealed as the risk factors for recurrent HAEC, while short-segment HSCR ( I2 =0%, RR=0.40, 95% CI 0.21-0.76, P =0.005) was revealed as a protective factor against recurrent HAEC.

CONCLUSION

The present review delineated the multiple risk factors for HAEC, which could assist in preventing the development of HAEC.

Hirschsprung's disease associated enterocolitis: A comprehensive review

Hirschsprung's disease (HSCR) is a congenital disorder characterized by failure of the neural crest cells to migrate and populate the distal bowel during gestation affecting different lengths of intestine leading to a distal functional obstruction. Surgical treatment is needed to correct HSCR once the diagnosis is confirmed by demonstrating the absence of ganglion cells or aganglionosis of the affected bowel segment. Hirschsprung's disease associated enterocolitis (HAEC) is an inflammatory complication associated with HSCR that can present either in the pre- or postoperative period and associated with increased morbidity and mortality. The pathogenesis of HAEC remains poorly understood, but intestinal dysmotility, dysbiosis and impaired mucosal defense and intestinal barrier function appear to play a significant role. There is no clear definition for HAEC, but the diagnosis is primarily clinical, and treatment is guided based on severity. Here, we aim to provide a comprehensive review of the clinical presentation, etiology, pathophysiology, and current therapeutic options for HAEC.

Serum Metabolomic Signatures of Hirschsprung's Disease Based on GC-MS and LC-MS

Hirschsprung's disease (HSCR) is a congenital digestive tract malformation characterized by the absence of intramural ganglion cells in the myenteric and submucosal plexuses along variable lengths of the gastrointestinal tract. Although the improvement of surgical methods has allowed great progress in the treatment of HSCR, its incidence and postoperative prognosis are still not ideal. The pathogenesis of HSCR remains unclear to date. In this study, metabolomic profiling of HSCR serum samples was performed by an integrated analysis of gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-high-resolution tandem mass spectrometry (LC-HRMS/MS) as well as multivariate statistical analyses. Based on the random forest algorithm and receiver operator characteristic analysis, 21 biomarkers related to HSCR were optimized. Several amino acid metabolism pathways were identified as important disordered pathways of HSCR, among which tryptophan metabolism was crucial. To our knowledge, this is the first serum metabolomics study focusing on HSCR, and it provides a new perspective for explaining the mechanism of HSCR.

Evaluation and Management of Postsurgical Patient With Hirschsprung Disease Neurogastroenterology & Motility Committee: Position Paper of North American Society of Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN)

Children with Hirschsprung disease have postoperative long-term sequelae in defecation that contribute to morbidity and mortality and significantly impact their quality of life. Pediatric patients experience ongoing long-term defecation concerns, which can include fecal incontinence (FI) and postoperative obstructive symptoms, such as constipation and Hirschsprung-associated enterocolitis. The American Pediatric Surgical Association has developed guidelines for management of these postoperative obstructive symptoms and FI. However, the evaluation and management of patients with postoperative defecation problems varies among different pediatric gastroenterology centers. This position paper from the Neurogastroenterology & Motility Committee of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition reviews the current evidence and provides suggestions for the evaluation and management of postoperative patients with Hirschsprung disease who present with persistent defecation problems.

Update on the Pathogenesis of the Hirschsprung-Associated Enterocolitis

Despite the significant progress that has been made in terms of understanding the pathophysiology and risk factors of Hirschsprung-associated enterocolitis (HAEC), the morbidity rate has remained unsatisfactorily stable, and clinical management of the condition continues to be challenging. Therefore, in the present literature review, we summarized the up-to-date advances that have been made regarding basic research on the pathogenesis of HAEC. Original articles published between August 2013 and October 2022 were searched in a number of databases, including PubMed, Web of Science, and Scopus. The keywords "Hirschsprung enterocolitis", "Hirschsprung's enterocolitis", "Hirschsprung's-associated enterocolitis", and "Hirschsprung-associated enterocolitis" were selected and reviewed. A total of 50 eligible articles were obtained. The latest findings of these research articles were grouped into gene, microbiome, barrier function, enteric nervous system, and immune state categories. The present review concludes that HAEC is shown to be a multifactorial clinical syndrome. Only deep insights into this syndrome, with an accrual of knowledge in terms of understanding its pathogenesis, will elicit the necessary changes that are required for managing this disease.

Risk factors for complications in patients with Hirschsprung disease while awaiting surgery: Beware of bowel perforation

BACKGROUND

Patients with Hirschsprung disease (HD) mostly undergo surgery around the age of three to six months. While awaiting surgery, therapy to treat the obstruction such as transanal irrigation (TAI) or laxatives is applied. The aim of this study was to gain insight in the prevalence and severity of complications occurring while awaiting surgery and to identify patient characteristics associated with the development of these complications.

METHODS

This study retrospectively analyzed data of patients with HD operated in our center between 2000 and 2021. Complications emerging while awaiting surgery were graded using Clavien-Dindo (CD). Patient characteristics as predictor of a complication were tested using logistic regression analysis.

RESULTS

Twenty-two of 132 (17%) included patients (preoperative treatment: 94% TAI; 2% laxatives; 2% other therapy) developed 45 complications while awaiting surgery, including predominantly major complications (91%). Bowel perforation occurred most frequently (n = 9, 7%) wherefrom six caused by TAI (5%), including three patients with total colon aganglionosis (TCA) (2%) counting one life-threatening and one lethal perforation. The other perforations were caused by meconium ileus (n = 2) and Hirschsprung associated enterocolitis (HAEC) (n = 1). Other frequent complications were: sepsis (5%), ileus (4%) and persistent obstruction (4%). Predictive factor for developing complication was TCA (OR 9.905, CI 2.994-32.772, p < 0.001).

CONCLUSION

We found a complication rate of 17% in patients while awaiting surgery, reporting bowel perforation most frequently. We found this complication in patients with TCA being highly dangerous causing one life-threatening and one lethal perforation. Therefore, we advise in patients with (suspected) TCA to limit the time awaiting surgery.

LEVEL OF EVIDENCE

level III.

One-stage transanal endorectal pull-through for Hirschsprung disease: experience with 229 neonates

OBJECTIVE

To evaluate the safety and efficacy of transanal endorectal pull-through (TEPT) and the long-term outcomes in newborns with Hirschsprung disease (HD).

METHODS

A total of 229 newborns with HD underwent one-stage TEPT between 2007 and 2020, and the diagnoses were confirmed by rectal biopsy. The perioperative clinical course for all patients was reviewed, and the postoperative short- and long-term outcomes were assessed.

RESULTS

A total of 229 neonates (187 male and 42 female) had a median age at TEPT of 17 days (range 6-28 days). Sixty-eight patients (29.7%) underwent TEPT combined with an abdominal approach or laparoscopy. Early postoperative complications (using the Clavien-Dindo grading system) were documented in 36 patients (15.7%), and late postoperative complications were noted in 9 patients (3.9%). The follow-up period in the remaining 165 children ranged from 1.2 to 14.0 years (median 5.0 years). A total of 106 of the patients older than four years old took part in an interview about bowel function, and 85 patients (80.2%) had bowel function scores (BFS) ≥ 18.

CONCLUSION

TEPT is effective and safe for HD in the neonatal period and presents with a low rate of complications and an acceptable outcome.

Associations of Mucosal Nerve Fiber Innervation Density with Hirschsprung-Associated Enterocolitis: A Retrospective Three-Center Cohort Study

OBJECTIVE

 Hirschsprung's disease (HSCR) is a congenital intestinal neurodevelopmental disorder characterized by the absence of enteric ganglion cells in the distal colon. Although Hirschsprung-associated enterocolitis (HAEC) is the most frequent life-threatening complication in HSCR, to date reliable biomarkers predicting the likelihood of HAEC are yet to be established. We established a three-center retrospective study including 104 HSCR patients surgically treated between 1998 and 2019.

MATERIALS AND METHODS

 Patient-derived cryopreserved or paraffin-preserved colonic tissue at surgery was analyzed via βIII-tubulin immunohistochemistry. We subsequently determined extrinsic mucosal nerve fiber density in resected rectosigmoid specimens and classified HSCR patients accordingly into nerve fiber-high or fiber-low groups. We compared the distribution of clinical parameters obtained from medical records between the fiber-high (n = 36) and fiber-low (n = 68) patient groups. We assessed the association between fiber phenotype and enterocolitis using univariate and multivariate logistic regression adjusted for age at operation.

RESULTS

 Enterocolitis was more prevalent in patients with sparse mucosal nerve fiber innervation (fiber-low phenotype, 87%) compared with the fiber-high phenotype (13%; p = 0.002). In addition, patients developing enterocolitis had a younger age at surgery (3 vs. 7 months; p = 0.016). In the univariate analysis, the odds for enterocolitis development in the fiber-low phenotype was 5.26 (95% confidence interval [CI], 1.67-16.59; p = 0.005) and 4.01 (95% CI, 1.22-13.17; p = 0.022) when adjusted for age.

CONCLUSION

 Here, we showed that HSCR patients with a low mucosal nerve fiber innervation grade in the distal aganglionic colon have a higher risk of developing HAEC. Consequently, histopathologic analysis of the nerve fiber innervation grade could serve as a novel sensitive prognostic marker associated with the development of enterocolitis in HSCR patients.

Hirschsprung-Associated Enterocolitis: Transformative Research from Bench to Bedside

Hirschsprung disease (HSCR) is a congenital disease that is characterized by the absence of intrinsic ganglion cells in the submucosal and myenteric plexuses of the distal colon and is the most common cause of congenital intestinal obstruction. Hirschsprung-associated enterocolitis (HAEC) is a life-threatening complication of HSCR, which can occur either before or after surgical resection of the aganglionic bowel. Even though HAEC is a leading cause of death in HSCR patients, its etiology and pathophysiology remain poorly understood. Various factors have been associated with HAEC, including the mucus barrier, microbiota, immune function, obstruction of the colon, and genetic variations. In this review, we examine our current mouse model of HAEC and how it informs our understanding of the disease. We also describe current emerging research that highlights the potential future of HAEC treatment.

Social determinants of health and Hirschsprung-associated enterocolitis

BACKGROUND

Hirschsprung-associated enterocolitis (HAEC) is the most common cause of morbidity and mortality in patients with Hirschsprung disease (HD). The objective of this study was to examine the association of social determinants of health (SDOH) with HAEC.

METHODS

A review of patients who underwent primary pull through for HD at our institution from 2014 to 2021 was performed. Clinical, surgical, and SDOH data were collected. HAEC was defined by an international scoring system. Categorical variables were analyzed via Fisher's exact tests and continuous variables with Mood's median tests.

RESULTS

One hundred patients were identified with 29 patients (29%) having at least one episode of HAEC during a median follow-up of 31 months (IQR: 11.7-55.7). Children who utilized public transportation for clinic visits, had one or more missed appointments, had any reported safety concerns, were involved with Child Protective Services, had parents/guardians who were not married, lived with people other than their immediate family, or had mothers who reported drug use or lack of prenatal care were found to have a higher likelihood of developing HAEC (p<0.04 for all). Age at HD diagnosis, age at pull through, operative approach, length of aganglionic colon, and Trisomy 21 were not significant predictors of HAEC.

CONCLUSIONS

In our series of 100 patients undergoing primary pull through, there was a significant correlation of HAEC with several social determinants of health elements while anatomical and clinical factors were not associated with HAEC. Attention to social determinants of health and identifying high-risk patients may serve to prevent morbidity and mortality from HAEC.

LEVEL OF EVIDENCE

III.

Systematic appraisal of the guidelines for the diagnosis and treatment of Hirschsprung's disease

BACKGROUND

Some guidelines for management of Hirschsprung's disease (HSCR, HD) have been developed, but their quality is vague. This study will systematically assess the quality of guidelines and analyze the key recommendations and the best evidence for guidelines.

METHODS

Applicable guidelines were retrieved using a systematic search of databases. The Appraisal of Guidelines for Research and Evaluation II (AGREE II) tool was used to assess the quality of the guidelines. Then, the recommendations and evidence for the included guidelines were extracted and compared.

RESULTS

A total of nine guidelines were included in this study, and only one had an overall standardized score of more than 60%, indicating that it is worthy of recommendation. The problems identified included ambiguous and low-quality evidence; obvious distributional heterogeneity among the recommendations; a lack of in-depth discussion on the interpretation of staging, diagnostic methods, conservative treatment, and surgical staging of disease.

CONCLUSION

The quality of guidelines varies widely, and there is a lack of high-quality professional opinions and supporting evidence for the main recommendations. At present, only comprehensive guidelines can be considered high-quality and there is still room for improvement.

Routine botulinum toxin injection one month after a Swenson pull-through does not change the incidence of Hirschsprung associated enterocolitis

PURPOSE

Patients with Hirschsprung disease (HD) are at risk of Hirschsprung associated enterocolitis (HAEC) following pull-through. The purpose of this study was to determine if routine Botulinum toxin (BT) injected one-month post pull-through decreases the incidence of HAEC.

METHODS

We reviewed patients who underwent a primary (not redo) pull-through operation for HD between April 2014 to December 2019. Over the most recent 18 months, BT was administered routinely one-month post-pull-through procedure; these patients were compared to the prior group that did not receive routine BT. A HAEC episode was defined as one that required initiation of treatment for obstructive symptoms in the inpatient or outpatient setting with antibiotics and irrigations. Categorical variables were compared using the nonparametric chi-square test or Fisher's exact test. Continuous variables were compared using the two-tailed Student's t-test. P-value <0.05 was determined to be statistically significant.

RESULTS

A total of 70 patients underwent Swenson pull-through during the study period (52% male). There were no statistically significant differences in demographics in the BT vs. non-BT group. Routine post-pull-through BT was given in 28 patients and did not significantly change HAEC incidence compared to the non-BT group (12/28, 43% vs. 16/42, 38%. P = 0.691). Of note, the BT group patients developed HAEC significantly sooner than the patients in the non-BT group (37.5 days vs. 253 days, p = 0.029). More patients in the BT group (n = 18, 64%) required at least one subsequent BT injection compared to the patients in the non-BT group (n = 11, 26%. P = 0.001).

CONCLUSIONS

We conclude that routine postoperative botulinum toxin injection given one month postoperatively from Swenson pull-through did not change the incidence of HAEC. A prospective controlled study is necessary to confirm these findings.

Management of Hirschsprung associated enterocolitis-How different are practice strategies? An international pediatric endosurgery group (IPEG) survey

INTRODUCTION

Hirschsprung's-associated enterocolitis (HAEC) is a common post-operative problem for patients with Hirschsprung disease (HSCR). However, treatment strategies remain variable among providers, institutions, and even nations. The purpose of this study was to identify differences in treatment patterns for HAEC.

METHODS

A questionnaire was distributed to members of the International Pediatric Endoscopic Group (IPEG) community that focused on HSCR and HAEC management strategies. Questionnaire responses were collected via the Research Electronic Data Capture (RedCap).

RESULTS

178 responses were obtained: 30% from North America, 20% South America, 20% Europe, 26% Asia, and 4% from Australia. 37% had a dedicated pediatric colorectal center. After diagnosis, 53% send patients home with irrigations, while 29% perform a primary PT before discharge; the type of PT varied between Soave (50%), Swenson (25%) and Duhamel (13%). Only 29 respondents (17%) stated their institution had guidelines for HAEC management; however, inpatient treatments were fairly consistent: 95% performed rectal irrigations, 93% obtained an abdominal radiograph, and 72% held feeds; 55% taught families irrigations before discharge. Utilization of Botulinum (BT) injections was mixed: 36% never utilized BT injections, 33% only used BT if irrigations were not tolerated, and 16% only injected BT for recurrent episodes. Preventative HAEC measures were also varied and included anal dilations (44%), prophylactic antibiotics (34%), probiotics (29%), and routine home irrigations (22%).

CONCLUSION

There is wide variation of care in managing enterocolitis episodes in patients with Hirschsprung disease. Further research leading to consensus guidelines and standardization practices can help improve the care for these patients.

LEVEL OF EVIDENCE

V TYPE OF STUDY: Treatment study/ survey.

Overabundance of Veillonella parvula promotes intestinal inflammation by activating macrophages via LPS-TLR4 pathway

Hirschsprung’s disease-associated enterocolitis (HAEC) is the most common complication of Hirschsprung’s disease (HSCR). The microbiome pattern of intestinal flora in HAEC patients was significantly abnormal compared to that in HSCR patients. The overabundance of V. parvula was detected in the gut of HAEC patients. To elucidate the pathological mechanisms of the overabundance of V. parvula, we established and analyzed inflammatory models induced by LPS or single-bacterial strain transplantation in vivo. The transplantation of V. parvula induced inflammatory response in the colon of mice. Besides, we found that LPS from V. parvula can significantly impair the barrier function of colonic epithelial cells and then activate macrophages which impaired pacemaker function of interstitial cells of Cajal (ICCs). It was thus a vicious cycle, where the macrophage-related inflammation caused by V. parvula via LPS-TLR4 pathway damaged the intestinal motility, which further aggravated the intestinal flora dysbiosis and promoted the development of HAEC. Itaconic acid could break the vicious cycle by inhibiting the activation of macrophages. It could be a potential therapeutic strategy for HAEC patients with intestinal flora dysbiosis.

Diagnostic accuracy of calretinin and acetylcholinesterase staining of rectal suction biopsies in Hirschsprung disease examined by unexperienced pathologists

Rectal suction biopsy (RSB) is a gold standard for diagnosing Hirschsprung disease (HD). Calretinin staining of RSB is increasingly used by experienced pathologists due to non-complex examination and comparable diagnostic accuracy with acetylcholinesterase (AChE). However, the diagnostic accuracy of calretinin examined by unexperienced pathologists remains to be elucidated. Therefore, we aim to compare diagnostic accuracy of calretinin with AChE on RSB for diagnosing HD when examined by unexperienced pathologists. We prospectively analyzed sections from RSB stained with AChE + HE and calretinin. Blinded examination was done by five unexperienced pathologists (pathology residents) and three experienced pathologists (senior pediatric gastro-enterology pathologists) assessing for the presence of HD. Cases for the study included ones proven to be HD on resection specimens and cases without HD. Diagnostic accuracy was determined calculating area under the curve (AUC), sensitivity, specificity, likelihood ratio, and posttest probability. Fleiss’ kappa analysis was performed to assess interobserver agreement between reviewers. Eleven of 18 included patients (61%) were diagnosed with HD. Comparing the diagnostic accuracy of unexperienced pathologists, calretinin versus AChE + HE showed sensitivity of 80.0% versus 74.5% and specificity of 100% versus 65.4%, AUC of 0.87 (0.78–0.96) versus 0.59 (0.45–0.72). Unexperienced pathologists showed substantial agreement with calretinin (kappa 0.72 [0.61–0.84]) and fair agreement with AChE + HE (kappa 0.34 [0.23–0.44]). We found calretinin having higher diagnostic accuracy in diagnosing HD compared to AChE + HE when examined by unexperienced pathologists. Therefore, we recommend to use calretinin as the standard technique for staining RSB in diagnosing HD.

Probiotics for the prevention of Hirschsprung-associated enterocolitis

BACKGROUND

Hirschsprung-associated enterocolitis (HAEC) is a leading cause of serious morbidity and potential mortality in children with Hirschsprung's disease (HD). People with HAEC suffer from intestinal inflammation, and present with diarrhoea, explosive stools, and abdominal distension. Probiotics are live microorganisms with beneficial health effects, which can optimise gastrointestinal function and gut flora. However, the efficacy and safety of probiotic supplementation in the prevention of HAEC remains unclear.

OBJECTIVES

To assess the effects of probiotic supplements used either alone or in combination with pharmacological interventions on the prevention of Hirschsprung-associated enterocolitis.

SEARCH METHODS

We searched CENTRAL, PubMed, Embase, the China BioMedical Literature database (CBM), the World Health Organization International Clinical Trials Registry, ClinicalTrials.gov, the Chinese Clinical Trials Registry, Australian New Zealand Clinical Trials Registry, and Clinical Trials Registry-India, from database inception to 27 February 2022. We also searched the reference lists of relevant articles and reviews for any additional trails.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing probiotics and placebo, or any other non-probiotic intervention, for the prevention of HAEC were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias of the included studies; disagreements were resolved by discussion with a third review author. We assessed the certainty of evidence using the GRADE approach. We calculated odds ratios (ORs) with 95% confidence intervals (CIs) for dichotomous outcomes.

MAIN RESULTS

We included two RCTs, with a total of 122 participants. We judged the overall risk of bias as high. We downgraded the evidence due to risk of bias (random sequence generation, allocation concealment, and blinding) and small sample size. The evidence is very uncertain about the effect of probiotics on the occurrence of HAEC (OR 0.58, 95% CI 0.10 to 3.43; I² = 74%; 2 studies, 120 participants; very low-certainty evidence). We found one included study that did not measure serious adverse events and one included study that reported no serious adverse events related to probiotics. Probiotics may result in little to no difference between probiotics and placebo in relation to the severity of children with HAEC at Grade I (OR 0.66, 95% CI 0.14 to 3.16; I² = 25%; 2 studies, 120 participants; low-certainty evidence). The effects of probiotics on the severity of HAEC at Grade II are very uncertain (OR 1.14, 95% CI 0.01 to 136.58; I² = 86%; 2 studies, 120 participants; very low-certainty evidence). Similarly, the evidence suggests that probiotics results in little to no difference in relation to the severity of HAEC at Grade III (OR 0.43, 95% CI 0.05 to 3.45; I² = 0%; 2 studies, 120 participants; low-certainty evidence). No overall mortality or withdrawals due to adverse events were reported. Probiotics may result in little to no difference in the recurrence of episodes of HAEC compared to placebo (OR 0.85, 95% CI 0.24 to 3.00; 1 study, 60 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

There is currently not enough evidence to assess the efficacy or safety of probiotics for the prevention of Hirschsprung-associated enterocolitis when compared with placebo. The presence of low- to very-low certainty evidence suggests that further well-designed and sufficiently powered RCTs are needed to clarify the true efficacy of probiotics.

The utilization of botulinum toxin for Hirschsprung disease

Patients with Hirschsprung disease (HD) can struggle with persistent obstructive symptoms even after a successful pull-through. These symptoms lead to stasis of stool and can result in Hirschsprung associated enterocolitis (HAEC). Recurrent episodes of HAEC warrant further workup; if there are no signs of mechanical obstruction or an aganglionic pull-through, the use of botulinum toxin injections to the internal anal sphincter has been utilized to relieve these symptoms. In this review, we describe the variations in botulinum toxin injection use and describe ongoing studies to prevent obstructive symptoms and Hirschsprung-associated enterocolitis (HAEC). Botulinum toxin injection utilization has been described for obstructive symptoms after HD pull-through, in the setting of active HAEC, and has been proposed to be part of the treatment algorithm for prevention of HAEC after pull-through. Dosing utilized for the injections, along with the complications, are also described. Prospective, multi-institutional trials are needed to identify the effectiveness of botulinum toxin injections in the outpatient/prophylactic setting as current data suggest some benefits in preventing future obstructive symptoms; however, other studies have conflicting results.

Prevalence of Hirschsprung-associated enterocolitis in patients with Hirschsprung disease

PURPOSE

Hirschsprung's associated enterocolitis (HAEC) is a complication of Hirschsprung's Disease (HD) with considerable morbidity and mortality. The variability in presentation leads to a wide variety of the reported prevalence pre-and postoperatively. This systematic review aimed to clarify the prevalence of HAEC in short-(S-HD), long (L-HD), TCA and the type of operation used.

METHODS

A systematic literature-based search for relevant cohorts was performed using Pubmed/Medline, Cochrane Library from its inception to May 2021. Studies reporting on pre-and postoperative enterocolitis, segment length, and surgical procedure (Soave, Swenson, Duhamel) were included. Pooled prevalence and subgroup analysis have been calculated for pre-and postoperative HAEC.

RESULTS

4738 articles were identified from the literature search, among which 57 studies, including 9744 preoperative and 8568 postoperative patients, were included. The groups were sorted by length of the aganglionic segment for further analysis. The pooled prevalence for preoperative HAEC was 18.3% for all types, 15.2% for S-HD and 26.1% for TCA. The pooled prevalence for postoperative HAEC was in total 18.2% for all segment lengths and used techniques. Subgroup analysis showed no significant difference in the occurrence of postoperative enterocolitis between the three techniques.

CONCLUSION

The prevalence of preoperative HAEC increases with segment length. However, pooled data suggest that the postoperative risk for developing HAEC, independently of the employed method and segment length, is comparable to the preoperative risk.

Enterocolitis Is a Risk Factor for Bowel Perforation in Neonates With Hirschsprung's Disease: A Retrospective Multicenter Study

BACKGROUND AND AIM

We evaluated the clinical features of neonatal Hirschsprung's disease (HD)-associated bowel perforation (perforated HD) and investigated risk factors related to it.

METHODS

We retrospectively collected clinical data of neonates (<1 month of age) with perforated HD from multicenters in China from January 2006 to December 2019. A total of 142 patients (6.7%) with perforated HD were enrolled in the study. A 1:2 matching method was used to compare the clinical information of HD patients with and without bowel perforation during the neonatal period. The risk factors for bowel perforation were identified using univariate and multivariate logistic risk regression analyses.

RESULTS

Perforation site was present in the proximal ganglionic bowel in 101 (71.1%) cases and the distal aganglionosis segment in 41 (28.9%) cases. Adjacent marginal tissue from the perforated intestine revealed varying degrees of inflammatory cell infiltration, and the severity of enterocolitis was higher in the proximal ganglionic bowel than in the distal aganglionosis segment (p < 0.05). In the univariable and multivariable logistic analyses, clinical symptoms, such as vomiting (adjusted OR = 2.06, 95% CI: 2.01-2.88, p < 0.05), and inflammation index in hematologic tests, such as neutrophil proportion (adjusted OR = 1.09, 95% CI: 1.05-1.33, p < 0.05) and CRP (adjusted OR = 2.13, 95% CI: 1.01-3.27, p < 0.05) were associated with increased risk for perforated HD.

CONCLUSION

Clinical Hirschsprung disease-associated enterocolitis (HAEC) highly correlated with perforated HD. Timely treatment of HAEC should be appropriate therapeutic approaches to prevent perforated HD.

Probiotic supplementation in neonates with congenital gastrointestinal surgical conditions: a pilot randomised controlled trial

OBJECTIVE

To evaluate whether probiotic supplementation attenuates gut-dysbiosis in neonates with congenital gastrointestinal surgical conditions (CGISC).

METHODS

Sixty-one neonates (≥35 weeks gestation) with CGISC were randomised to receive daily supplementation with a triple-strain bifidobacterial probiotic (n = 30) or placebo (n = 31) until discharge. Stool microbiota was analysed using 16S ribosomal RNA gene sequencing on samples collected before (T1), 1 week (T2), and 2 weeks (T3) after supplementation and before discharge (T4). The primary outcome was the sum of the relative abundance of potentially pathogenic families of Clostridiaceae, Enterobacteriaceae, Enterococcaceae, Pseudomonaceae, Staphylococcaeae, Streptococcaceae, and Yersiniaceae at T3.

RESULTS

The median gestational age [38 weeks (IQR: 37.1-38.9)] was similar in both groups. The probiotic group had lower rates of caesarean deliveries (40% versus 70%, p = 0.02). The relative abundance of potentially pathogenic families was lower in the probiotic group compared to placebo at T3 [(median: 50.4 (IQR: 26.6-67.6) versus 67.1 (IQR: 50.9-96.2); p = 0.04). Relative abundance of Bifidobacteriaceae was higher in the probiotic group at T3 [(median: 39.8 (IQR: 24.9-52.1) versus 0.03 (IQR 0.02-2.1); p < 0.001). Stratified analysis continued to show a higher abundance of Bifidobacteriaceae in the probiotic group, irrespective of the mode of delivery.

CONCLUSIONS

Probiotic supplementation attenuated gut dysbiosis in neonates with CGISC.

TRIAL REGISTRATION

http://www.anzctr.org.au (ACTRN12617001401347).

IMPACT

Probiotic supplementation attenuates gut dysbiosis and improves stool short-chain fatty acid levels in neonates with congenital gastrointestinal surgical conditions. This is the second pilot RCT of probiotic supplementation in neonates with congenital gastrointestinal conditions. These findings will pave the way for conducting multicentre RCTs in this area.

Clinical Efficacy of an Indwelling Transanal Tube for the Prevention of Anastomotic Leakage After Hirschsprung's Disease: A Single Center Experience with Chinese Patients

Background: The aim of this study was to investigate the clinical effectiveness of an indwelling transanal tube for the prevention of anastomotic leakage (AL) after a radical operation for Hirschsprung's disease (HD). Methods: We retrospectively analyzed the clinical data from 158 patients who had undergone laparoscopic-assisted Soave procedures for HD at our hospital from May 2015 to May 2019. Patients were divided into two groups depending upon whether the anal drainage tube was retained or not retained: an indwelling group (group A, n = 86) and a no-indwelling group (group B, n = 72). Results: All 158 children had a successful operation by a laparoscopic technique. There was no significant difference in the duration of the operation, the length of the incision, the amount of bleeding, or the postoperative hospitalization time between the two groups. Compared with the no-indwelling group, maintaining the transanal tube had significant advantages for preventing incidences of AL (P < .05). The 4-year follow-up showed that the incidence of postoperative enterocolitis with the indwelling transanal tube was significantly lower than in the group without the drainage tube (P < .05). Conclusions: The laparoscopic-assisted Soave procedure with an indwelling transanal tube is a safe and feasible method for the treatment of HD in children. This method can not only drain intestinal contents but also reduce the occurrence of AL.

Outpatient Botulinum Injections for Early Obstructive Symptoms in Patients with Hirschsprung Disease

INTRODUCTION

Botulinum toxin (BT) injections may play a role in preventing Hirschsprung associated enterocolitis (HAEC) episodes related to internal anal sphincter (IAS dysfunction). Our aim was to determine the association of outpatient BT injections for early obstructive symptoms on the development of HAEC.

METHODS

A retrospective review of children who underwent definitive surgery for Hirschsprung disease (HSCR) from July 2010 - July 2020 was performed. The timing from pull-through to first HAEC episode and to first BT injection was recorded. Primary analysis focused on the rate of HAEC episodes and timing between episodes in patients who did and did not receive BT injections.

RESULTS

Eighty patients were included. Sixty patients (75%) were male, 15 (19%) were diagnosed with trisomy 21, and 58 (72.5%) had short-segment disease. The median time to pull-through was 150 days (IQR 16, 132). Eight patients (10%) had neither an episode of HAEC or BT injections and were not included in further analysis. Forty-six patients (64%) experienced at least one episode of HAEC, while 64 patients (89%) had at least one outpatient BT injection. Compared to patients who never received BT injections (n = 9) and those who developed HAEC prior to BT injections (n = 35), significantly fewer patients who received BT injections first (n = 28) developed enterocolitis (P < 0.001), with no patient developing more than one HAEC episode.

CONCLUSION

Outpatient BT is associated with decreased episodes of HAEC and increased interval between HAEC episodes requiring inpatient treatment. Scheduling outpatient BT injections to manage obstructive symptoms may be beneficial after pull-through for HSCR.

Persistent bowel dysfunction after surgery for Hirschsprung’s disease: A neuropathological perspective

Hirschsprung’s disease (HD) is a congenital disorder, characterized by aganglionosis in the distal part of the gastrointestinal tract. Despite complete surgical resection of the aganglionic segment, both constipation and fecal incontinence persist in a considerable number of patients with limited treatment options. There is growing evidence for structural abnormalities in the ganglionic bowel proximal to the aganglionosis in both humans and animals with HD, which may play a role in persistent bowel dysfunction. These abnormalities include: (1) Histopathological abnormalities of enteric neural cells; (2) Imbalanced expression of neurotransmitters and neuroproteins; (3) Abnormal expression of enteric pacemaker cells; (4) Abnormalities of smooth muscle cells; and (5) Abnormalities within the extracellular matrix. Hence, a better understanding of these previously unrecognized neuropathological abnormalities may improve follow-up and treatment in patients with HD suffering from persistent bowel dysfunction following surgical correction. In the long term, further combination of clinical and neuropathological data will hopefully enable a translational step towards more individual treatment for HD.

Reoperative techniques and management in Hirschsprung disease: a narrative review

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

Enteric glia in homeostasis and disease: From fundamental biology to human pathology

Glia, the non-neuronal cells of the nervous system, were long considered secondary cells only necessary for supporting the functions of their more important neuronal neighbors. Work by many groups over the past two decades has completely overturned this notion, revealing the myriad and vital functions of glia in nervous system development, plasticity, and health. The largest population of glia outside the brain is in the enteric nervous system, a division of the autonomic nervous system that constitutes a key node of the gut-brain axis. Here, we review the latest in the understanding of these enteric glia in mammals with a focus on their putative roles in human health and disease.

Lack of Mucosal Cholinergic Innervation Is Associated With Increased Risk of Enterocolitis in Hirschsprung's Disease

BACKGROUND & AIMS

Hirschsprung's disease (HSCR) is a congenital intestinal motility disorder defined by the absence of enteric neuronal cells (ganglia) in the distal gut. The development of HSCR-associated enterocolitis remains a life-threatening complication. Absence of enteric ganglia implicates innervation of acetylcholine-secreting (cholinergic) nerve fibers. Cholinergic signals have been reported to control excessive inflammation, but the impact on HSCR-associated enterocolitis is unknown.

METHODS

We enrolled 44 HSCR patients in a prospective multicenter study and grouped them according to their degree of colonic mucosal acetylcholinesterase-positive innervation into low-fiber and high-fiber patient groups. The fiber phenotype was correlated with the tissue cytokine profile as well as immune cell frequencies using Luminex analysis and fluorescence-activated cell sorting analysis of colonic tissue and immune cells. Using confocal immunofluorescence microscopy, macrophages were identified in close proximity to nerve fibers and characterized by RNA-seq analysis. Microbial dysbiosis was analyzed in colonic tissue using 16S-rDNA gene sequencing. Finally, the fiber phenotype was correlated with postoperative enterocolitis manifestation.

RESULTS

The presence of mucosal nerve fiber innervation correlated with reduced T-helper 17 cytokines and cell frequencies. In high-fiber tissue, macrophages co-localized with nerve fibers and expressed significantly less interleukin 23 than macrophages from low-fiber tissue. HSCR patients lacking mucosal nerve fibers showed microbial dysbiosis and had a higher incidence of postoperative enterocolitis.

CONCLUSIONS

The mucosal fiber phenotype might serve as a prognostic marker for enterocolitis development in HSCR patients and may offer an approach to personalized patient care and new therapeutic options.

Intestinal proinflammatory macrophages induce a phenotypic switch in interstitial cells of Cajal

Interstitial cells of Cajal (ICCs) are pacemaker cells in the intestine, and their function can be compromised by loss of C-KIT expression. Macrophage activation has been identified in intestine affected by Hirschsprung disease-associated enterocolitis (HAEC). In this study, we examined proinflammatory macrophage activation and explored the mechanisms by which it downregulates C-KIT expression in ICCs in colon affected by HAEC. We found that macrophage activation and TNF-α production were dramatically increased in the proximal dilated colon of HAEC patients and 3-week-old Ednrb-/- mice. Moreover, ICCs lost their C-KIT+ phenotype in the dilated colon, resulting in damaged pacemaker function and intestinal dysmotility. However, macrophage depletion or TNF-α neutralization led to recovery of ICC phenotype and restored their pacemaker function. In isolated ICCs, TNF-α-mediated phosphorylation of p65 induced overexpression of microRNA-221 (miR-221), resulting in suppression of C-KIT expression and pacemaker currents. We also identified a TNF-α/NF-κB/miR-221 pathway that downregulated C-KIT expression in ICCs in the colon affected by HAEC. These findings suggest the important roles of proinflammatory macrophage activation in a phenotypic switch of ICCs, representing a promising therapeutic target for HAEC.

Zebrafish: A Model Organism for Studying Enteric Nervous System Development and Disease

The Enteric Nervous System (ENS) is a large network of enteric neurons and glia that regulates various processes in the gastrointestinal tract including motility, local blood flow, mucosal transport and secretion. The ENS is derived from stem cells coming from the neural crest that migrate into and along the primitive gut. Defects in ENS establishment cause enteric neuropathies, including Hirschsprung disease (HSCR), which is characterized by an absence of enteric neural crest cells in the distal part of the colon. In this review, we discuss the use of zebrafish as a model organism to study the development of the ENS. The accessibility of the rapidly developing gut in zebrafish embryos and larvae, enables in vivo visualization of ENS development, peristalsis and gut transit. These properties make the zebrafish a highly suitable model to bring new insights into ENS development, as well as in HSCR pathogenesis. Zebrafish have already proven fruitful in studying ENS functionality and in the validation of novel HSCR risk genes. With the rapid advancements in gene editing techniques and their unique properties, research using zebrafish as a disease model, will further increase our understanding on the genetics underlying HSCR, as well as possible treatment options for this disease.

Correlation analysis of IL-11 polymorphisms and Hirschsprung disease subtype susceptibility in Southern Chinese Children

BACKGROUND

Hirschsprung disease (HSCR) is a hereditary defect, which is characterized by the absence of enteric ganglia and is frequently concurrent with Hirschsprung-associated enterocolitis (HAEC). However, the pathogenesis for HSCR is complicated and remains unclear. Recent studies have shown that pro-inflammatory cytokines such as interleukin-11 (IL-11) are involved in the enteric nervous system's progress. It was found that IL-11 SNPs (rs8104023 and rs4252546) are associated with HSCR in the Korean population waiting for replication in an independent cohort. This study evaluated the relationship between IL-11 and the susceptibility of patients to HSCR by performing subphenotype interaction examination, HAEC pre-/post-surgical patient-only association analysis, and independence testing.

METHODS

In this study, a cohort consisting of children from Southern China, comprising 1470 cases and 1473 controls, was chosen to examine the relationship between two polymorphisms (rs8104023 and rs4252546 in IL-11) and susceptibility to HSCR by replication research, subphenotype association analysis, and independence testing.

RESULTS

The results showed that IL-11 gene polymorphisms (rs8104023 and rs4252546) are not associated with the risk of HSCR in the Chinese population. The results of both short-segment and long-segment (S-HSCR and L-HSCR) surgery (3.34 ≤ OR ≤ 4.05, 0.02 ≤ P ≤ 0.04) showed that single nucleotide polymorphisms (SNP) rs8104023 is associated with susceptibility to HAEC.

CONCLUSIONS

This study explored the relationship between genetic polymorphisms and susceptibility to HAEC in HSCR subtypes for the first time. These findings should be replicated in a larger and multicentre study.

Colonoscopic Diagnosis of Postoperative Gastrointestinal Bleeding in Patients With Hirschsprung's Disease

Aim: Postoperative lower gastrointestinal bleeding in children with Hirschsprung's Disease (HSCR) is a non-specific symptom, which may be caused by various etiologies. Our current study aims to utilize colonoscopy to diagnose the causes of postoperative hematochezia and to analyze its feasibility, accuracy, and safety. Methods: Twenty-four patients with HSCR with postoperative lower gastrointestinal bleeding or occult blood in the stool were enrolled in this study. The postoperative onset duration, age at examination, accompanied anomalies were recorded. After bowel preparation, all patients underwent colonoscopy. According to visual findings, mucosal biopsy was performed, followed by pathological diagnosis. Further treatment was determined according to the visual findings and pathological diagnosis. All patients were followed up for 6 months including therapeutic outcomes and recurrence of symptoms. Results: The mean onset duration was (221.3 ± 216.8) days postoperatively (ranging from 25 to 768 days). The mean age at examination was (41.0 ± 29.4) months. There was no significant difference in the onset days among each group (all, p > 0.05). Based on visual and pathological findings, there were 11 cases of HSCR associated enterocolitis (HAEC), 4 cases of anastomotic leakage, 7 cases of anastomotic inflammation, 1 case of juvenile polyp, and 1 case of inflammatory pseudopolyp. Intraluminal saline irrigation, thrombin treatment or colorectal polyp electrocision was performed according to intraoperative diagnosis. Patients with HEAC and anastomotic inflammation underwent antibiotics therapy and colorectal irrigation. Patients with leakage underwent reoperation. The highest incidence of accompanied symptoms of diarrhea existed in HEAC group (p = 0.02) and fever in leakage group (p = 0.02), respectively. No perforation or aggravated bleeding occurs in any patients. All patients gained uneventful recovery during follow-up period. Conclusions: Colonoscopy is a safe, accurate and timely examination for HSCR patients with postoperative lower gastrointestinal bleeding. The visual findings and biopsy may provide accurate diagnosis and guide treatment for this subset of patients.

Comparison of Two Different Cut-Off Values of Scoring System for Diagnosis of Hirschsprung-Associated Enterocolitis After Transanal Endorectal Pull-Through

Background: Hirschsprung-associated enterocolitis (HAEC) is a major contributor in the mortality of Hirschsprung disease (HSCR) patients that can occur both preoperatively and post-operatively. Several cut-off values of HAEC score have been used, i.e., ≥10 and ≥4. Here, we compared the HAEC frequency after transanal endorectal pull-through (TEPT) using two cut-offs of scoring system and associated them with the risk factors. Methods: Cross-sectional analysis was conducted using medical records of HSCR patients who were aged ≤18 years old and underwent TEPT at our institution, Indonesia between 2009 and 2016. HAEC was determined using the scoring system with cut-off values of ≥10 and ≥4. Results: Seventy subjects were used in the final analysis, consisting of 44 males and 26 females. There was a significant difference in one HAEC finding between the ≥10 and ≥4 cut-off groups; diarrhea with explosive stools (p = 0.002). The HAEC frequency was 5/70 (7.1%) and 49/70 (70%) patients using cut-off values of ≥10 and ≥4 (p < 0.0001), respectively. We found that patients with anemia (i.e., iron deficiency anemia) had a higher risk of HAEC after TEPT than patients with normal hemoglobin level with OR of 3.77 (95% CI = 1.28-11.1; p = 0.027), while no associations were found between other variables, including sex, age at diagnosis, age at definitive therapy, albumin level, and nutritional status and HAEC following TEPT (p = 0.87, 0.15, 0.33, 0.26, and 0.60, respectively). Also, no associations were observed between maternal education level, mother's age at pregnancy and gestational age and HAEC after definitive surgery (p = 0.10, 0.46, and 0.86, respectively). Conclusions: This report is the first study comparing two different cut-off values of scoring system to evaluate the HAEC frequency after TEPT and results suggest further using cut-off of ≥4 to expand the diagnosis of HAEC. Moreover, we also show for the first time that hemoglobin level is a strong risk factor for the HAEC development after TEPT.

Postoperative enterocolitis assessment using two different cut-off values in the HAEC score in Hirschsprung patients undergoing Duhamel and Soave pull-through

Background

Hirschsprung-associated enterocolitis (HAEC) is the most severe and potentially lethal complication of Hirschsprung disease (HSCR) which might occur following definitive surgery. Our objectives were: 1) to compare the incidence of HAEC after Duhamel and Soave procedures using different cut-off values of the HAEC scoring method; and 2) to associate them with the risk factors, including sex, aganglionosis type, mothers’ age at childbirth, gestational age, and mothers’ educational level.

Methods

Medical records of patients with HSCR who underwent Soave and Duhamel procedures in our institution, Indonesia (January 2012 – December 2016) were reviewed retrospectively. Two cut-off values of the HAEC scoring system (i.e., ≥10 and ≥ 4) were utilized.

Results

Eighty-three patients with HSCR were recruited in this study (Soave: 37 males and 7 females vs. Duhamel: 28 males and 11 females; p = 0.18). The incidence of HAEC after surgery was 14/83 (16.9%) and 38/83 (45.8%) for cut-off values of ≥10 and ≥ 4, respectively (p = 0.00012), and tended to have an association with sex (p = 0.09). Although it was not statistically significant (p = 0.07), the frequency of HAEC after Soave procedure tended to be higher in patients with their mother’s age of ≤35 years at childbirth than those with their mother’s age of > 35 years (OR = 7.9; 95% CI = 0.9–72.1). Multivariate analysis indicated none of the risk factors were associated with the frequency of HAEC after definitive surgery.

Conclusions

The lower cut-off value of ≥4 might increase the possibility to diagnose HAEC, particularly the mild cases. The incidence of HAEC after definitive surgery was not associated with any risk factors in our cohort patients. Further multicenter studies with a larger sample size are necessary to confirm our findings.

Lipopolysaccharide upregulates miR-132/212 in Hirschsprung-associated enterocolitis, facilitating pyroptosis by activating NLRP3 inflammasome via targeting Sirtuin 1 (SIRT1)

Hirschsprung disease (HSCR) is a congenital disorder attributed to the failure of the neural crest derivatives migrating and/or differentiating along the hindgut. The most frequent complication in Hirschsprung disease patients is Hirschsprung-associated enterocolitis (HAEC). However, its pathogenesis has not been fully understood. This study investigated miRNAs influenced by Lipopolysaccharide (LPS) in postoperative HAEC patients, their effect on enterocolitis and the underlying mechanism. MiR-132 and miR-212 were up-regulated in HAEC dilated tissues and LPS-treated mice enteritis samples. LPS-stimulated HT29 cells showed a high expression of miR-132 and miR-212. QRT-PCR analysis, western blotting, luciferase reporter assay, and flow cytometric analysis were carried out in vitro, showing that miR-132 and miR-212 could directly inhibit Sirtuin 1 (SIRT1) expression. Consequently, SIRT1 deficiency in LPS-stimulated HT29 cell line and LPS-treated mice activated NLRP3 inflammasome and Caspase-1-mediated pyroptosis. Furthermore, the above inflammation activation was reversed by miR-132/212 inhibitor or SIRT1 overexpression plasmid transfection.In conclusion, LPS upregulated miR-132 and miR-212 expression in HAEC, suppressing SIRT1 and facilitating NLRP3 inflammasome activation, which induced pyroptosis. Our findings illustrated the role of LPS/miR-132/-212/SIRT1/NLRP3 regulatory network in the occurrence and progression of HAEC and proposed a new molecular pathway for LPS-mediated cell pyroptosis.

Increased protease activated receptors in the colon of patients with Hirschsprung's disease

PURPOSE

The pathophysiology of Hirschsprung's associated enterocolitis (HAEC) is not understood. Abnormal intestinal motility and altered intestinal epithelial barrier function have been suggested to play a key role in the causation of HAEC. Protease-activated receptors (PARs) 1 and 2, have been implicated in inflammatory reactions, intestinal permeability and modulation of motility in the gut.

METHODS

We investigated PAR-1 and PAR-2 protein expression in aganglionic and ganglionic regions of patients with Hirschsprung's Disease (HSCR) (n = 10) versus normal control colon (n = 10). Protein distribution was assessed by using immunofluorescence and confocal microscopy. Gene and protein expression were quantified using quantitative real-time polymerase chain reaction (qPCR), western blot analysis, and densitometry.

RESULTS

qPCR and Western blot analysis revealed that PAR-1 and PAR-2 expression was significantly increased in ganglionic and aganglionic bowel in HSCR compared to controls (p < 0.003). Confocal microscopy revealed strong PAR-1 and PAR-2 expression in smooth muscles, interstitial cells of Cajal (ICCs), platelet-derived growth factor-alpha receptor-positive (PDGFRα⁺) cells, enteric neurons and epithelium in the ganglionic and aganglionic bowel compared to controls.

CONCLUSION

Increased PAR-1 and PAR-2 expression in the colon of patients with HSCR suggests that excessive local release of PAR activating proteases may trigger inflammatory responses leading to HAEC.

Total colonic aganglionosis: multicentre study of surgical treatment and patient-reported outcomes up to adulthood

Background

Surgery for total colonic aganglionosis (TCA) is designed to preserve continence and achieve satisfactory quality of life. This study evaluated a comprehensive group of clinical and social outcomes.

Methods

An international multicentre study from eight Nordic hospitals involving examination of case records and a patient‐reported questionnaire survey of all patients born with TCA between 1987 and 2006 was undertaken.

Results

Of a total of 116 patients, five (4·3 per cent) had died and 102 were traced. Over a median follow‐up of 12 (range 0·3–33) years, bowel continuity was established in 75 (73·5 per cent) at a median age of 11 (0·5–156) months. Mucosectomy with a short muscular cuff and straight ileoanal anastomosis (SIAA) (29 patients) or with a J pouch (JIAA) (26) were the most common reconstructions (55 of 72, 76 per cent). Major early postoperative complications requiring surgical intervention were observed in four (6 per cent) of the 72 patients. In 57 children aged over 4 years, long‐term functional bowel symptoms after reconstruction included difficulties in holding back defaecation in 22 (39 per cent), more than one faecal accident per week in nine (16 per cent), increased frequency of defaecation in 51 (89 per cent), and social restrictions due to bowel symptoms in 35 (61 per cent). Enterocolitis occurred in 35 (47 per cent) of 72 patients. Supplementary enteral and/or parenteral nutrition was required by 51 (55 per cent) of 93 patients at any time during follow‐up. Of 56 responders aged 2–20 years, true low BMI for age was found in 20 (36 per cent) and 13 (23 per cent) were short for age.

Conclusion

Reconstruction for TCA was associated with persistent bowel symptoms, and enterocolitis remained common. Multidisciplinary follow‐up, including continuity of care in adulthood, might improve care standards in patients with TCA.

Clinical Outcomes After Staged and Primary Laparotomy Soave Procedure for Total Colonic Aganglionosis: a Single-Center Experience from 2007 to 2017

PURPOSE

To compare the clinical outcomes of the staged laparotomy Soave procedure (SLSP) and primary laparotomy Soave procedure (PLSP) for patients with total colonic aganglionosis (TCA), including some patients who underwent surgical treatment after the age of 1 year.

METHODS

A retrospective, comparative study of TCA patients who underwent SLSP or PLSP at Beijing Children Hospital from 2007 to 2017 was conducted. The primary outcomes were height-for-age (HFA), weight-for-age (WFA), and bowel function score (BFS); the major types of postoperative complications were also analyzed.

RESULTS

Thirty-five patients (SLSP = 14, PLSP = 21) were included. The patients in the SLSP group underwent an enterostomy at a median age of 47 (14, 104) days. The median age at the time of the Soave procedure showed no significant difference between the two groups ([181 (131,346) vs 55 (29, 343)] days, p = 0.072). No significant differences between groups were noted in terms of presenting symptoms, perioperative results, and postoperative outcomes. Twenty-three patients (SLSP = 8, PLSP = 15) were followed for more than 1 year. Both the SLSP and PLSP groups showed similar operative mortality ([1/14, 7.1%] vs [3/21, 14.3%], p = 0.635) and complication rates ([postoperative enterocolitis, (5/8, 62.5%) vs (5/15, 33.3%), p = 0.221] [perianal excoriation, (7/8, 87.5%) vs (10/15, 66.6%), p = 0.369]). Nineteen patients (19/23, 82.6%) had normal growth according to the median percentage of HFA or WFA. Mean BFS was 15.9 ± 3.3 in the 15 patients aged older than 4 years who were followed up. Six patients (SLSP = 1, PLSP = 5) who underwent surgical treatment aged older than 1 year were all alive with good outcomes.

CONCLUSION

PLSP and SLSP had equivalent clinical outcomes, but enterocolitis and perianal excoriation after the Soave procedure need to be managed carefully. PLSP is a feasible option for older TCA patients after conservative treatment.

Epithelial changes of congenital intestinal obstruction in a rat model

Introduction

Intestinal atresia is a rare congenital affliction that is often associated with severe bacterial infections despite adequate neonatal surgery. Previous studies have focused on enteric nervous system variations. We hypothesized that epithelial systems (ES) may also be involved in the pathophysiology of postnatal disorders.

Materials and methods

Global gene expression was measured by transcriptomic analysis in a rat model of induced intestinal atresia. The analyses then focused on genes involved in ES (enterocytes and goblet cells). Rat fetus small intestines at various stages of development (ED15, ED17, ED19, and ED21, n = 22), were used as non-operated controls and compared to the upper and lower segments of rat fetus small intestines with an induced atresia (n = 14; ligature at ED18). The pattern of gene expression was then confirmed by histochemistry, electron microscopy, and RT-qPCR.

Results

From ED15 to ED21, the expression of several genes exhibited a physiological increase of ES markers, with a significant increase at the end of gestation. The operated embryos exhibited significantly higher variations of gene expression in the proximal segment than in the distal segment in terms of absorption and the epithelial barrier. An increase in goblet cells and markers was observed in the proximal segment compared to the controls.

Conclusion

Fetal intestinal obstruction accelerates maturation in the proximal segment and disrupts the intestinal wall in the distal segment, with a decrease in the number of mucosal cells. Moreover, the epithelial cells underwent significant changes, supporting the notion that intestinal disorders involve more than the ENS.

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.

Comparison of pre-operative Hirschsprung-associated enterocolitis using classical criteria and Delphi method: A diagnostic study

Background

Hirschsprung-associated enterocolitis (HAEC) is the most common complication of Hirschsprung disease (HSCR) that may happen pre-operatively. Several methods have been reported to determine HAEC. Because the diagnosis of pre-operative HAEC might change the surgical plan, we aimed to determine the accuracy of the classical criteria for diagnosis of pre-operative HAEC and using the Delphi method as a gold standard.

Methods

Medical records of HSCR children who were admitted to our hospital from January 2009 to December 2015 were retrospectively analyzed.

Results

Ninety-six subjects were involved in this study, consisting of 74 males and 22 females. The most common findings of the Delphi score were abdominal distension (100%) and dilated loops of bowel (100%), followed by leucocytosis (78.6%), lethargy (71.4%), cutoff sign in rectosigmoid with absence of distal air (71.4%), and shift to left (71.4%). The frequency of pre-operative HAEC was 4.2% and 14.6% using the classical criteria and Delphi method, respectively (p = 0.016). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy rates of the classical criteria for diagnosis of pre-operative HAEC were 14.3% (95% CI: 1.8-42.8%), 97.6% (95% CI: 91.5-99.7%), 50% (95% CI: 13.3-86.7%), 87% (95% CI: 84.3-89.2), and 85.4% (95% CI: 76.7-91.8%), respectively.

Conclusions

The frequency of pre-operative HAEC is low in our hospital. The accuracy of the classical criteria is considered relatively moderate for diagnosis of pre-operative HAEC.

Postoperative Pullthrough Obstruction in Hirschsprung Disease: Etiologies and Diagnosis

Some patients continue to have obstructive symptoms and/or incontinence after pullthrough surgery for Hirschsprung disease. Incontinence can be due to injury to the anal sphincter and/or dentate line, abnormal colonic motility (nonretentive), or a chronic large stool burden (retentive). A diagnostic algorithm based on clinical and pathological evaluations can be applied to distinguish potential etiologies for obstructive symptoms, which segregate into anatomic (mechanical or histopathological) or physiologic subgroups. Valuable clinical information may be obtained by anorectal examination under anesthesia, radiographic studies, and anorectal or colonic manometry. In addition, histopathological review of a patient's original resection specimen(s) as well as postoperative biopsies of the neorectum usually are an important component of the diagnostic workup. Goals for the surgical pathologist are to exclude incomplete resection of the aganglionic segment or transition zone and to identify other neuromuscular pathology that might explain the patient's dysmotility. Diagnoses established from a combination of clinical and pathological data dramatically alter management strategies. In rare instances, reoperative pullthrough surgery is required, in which case the pathologist must be aware of histopathological features specific to redo pullthrough resection specimens.