Surgery, Surgical Pathology, and Postoperative Management of Patients With Hirschsprung Disease

Pitfalls and considerations in the diagnosis of Hirschsprung's disease: A focus on pathological assessment

Hirschsprung's disease (HSCR) is a congenital disorder of the intestine characterized by the absence of ganglion cells (GCs) in the myenteric and submucosal plexuses of the distal colon, leading to functional obstruction. The diagnosis of HSCR relies heavily on histopathological examination, yet pitfalls abound. Underdiagnosis can lead to delayed diagnosis, the need for reoperation, or risk of complications; conversely, overdiagnosis can lead to unnecessary surgery and its associated side effects. This comprehensive pictorial review addresses common diagnostic challenges using cases from our hospital, a tertiary pediatric facility and referral center for HSCR patients, and emphasizes the need for close cooperation among pathologists, surgeons, pediatric gastroenterologists, and radiologists to achieve optimal management for patients with HSCR.

Anorectal Malformations and Hirschsprung Disease: A 30-Year Retrospective Outreach Review

Objective This study analyses the indications for and outcomes of primary and redo surgeries for anorectal malformations (ARMs) and Hirschsprung disease (HD) in developing, resource-limited countries. The study seeks to identify trends in primary surgery complication rates, evaluate the indications for reoperation and explore potential strategies to improve surgical management and long-term outcomes for children with ARM and HD in these settings. Methodology A retrospective cohort analysis was conducted on data collected by the Kind Cut for Kids (KCFK) surgical outreach program, a charitable initiative that provides paediatric surgical care in under-served regions. Data was collected over a 30-year period across 22 developing countries. The dataset contained 2,498 observations linked to ARM or HD, which was filtered to include those with primary surgeries, reoperations for prior complications and management of complications of any surgery done by the visiting team. Clinical data included demographics, pathology classification, surgical details, and postoperative outcomes. Results The final cohort included 496 ARM patients and 224 HD patients, with 65% and 41%, respectively, undergoing primary corrective surgeries. Among ARM cases, 25% required redo surgeries, with malposition (33%), strictures (24%), or prolapse (8%) being the most common indications. In HD, 45% of patients required redo procedures, primarily for strictures (19%), prolapse (9%), or acquired fistulas (4%). The most common redo procedures for ARMs were the posterior sagittal anorectoplasty (PSARP) (58%) or anorectal angle plication (10%). For HD patients, PSARP (11%) and the Swenson procedure (10%) were the most common corrective redo procedures. Due to the focus of KCFK visits, there are significant data gaps pertaining to primary surgical details, reoperation indications and follow-up data. This reflects the challenges of managing these conditions in resource-limited environments and with an outreach program. Conclusion This study highlights high rates of complications from primary surgeries in ARM and HD cases treated in resource-limited settings, which emphasises the need for enhanced surgical precision, structured postoperative care, and consistent follow-up protocols, as well as education of surgeons in the countries visited. Targeted interventions such as capacity-building initiatives, tailored consensus guidelines, and telemedicine integration are critical to addressing disparities in care. Future prospective studies with standardised data collection and outcome metrics are essential to validate these findings and improve care delivery for children with ARM and HD in underserved regions.

Histopathologic Concerns and Diagnostic Challenges in Hirschsprung's Disease: An Eastern European Single-Center Observational Study

BACKGROUND

We proposed a comprehensive clinicopathological study involving the characterization of the study cohort and a comparative analysis of biopsies and surgical specimens from patients with Hirschsprung's disease. The study was complemented by the diagnostic value of calretinin, CD56, and S-100 immunohistochemistry.

METHODS

Descriptive statistical analysis of diagnostic variables in the group of biopsy specimens (n = 32) and bowel resection specimens (n = 16) was performed. The pattern of calretinin and CD56 expression in Meissner's plexus elements was analyzed and the maximum thicknesses of the nerve fibers were measured using morphometry with S100-immunostained sections.

CONCLUSIONS

Coupled calretinin-CD56 immunohistochemistry is useful in diagnosing ganglion cell paucity biopsies or specimens with incomplete submucosa. In cases where there are no ganglion cells but there are calretinin-positive nerve fibrils in the lamina propria without nerve trunk (NT) hypertrophy, re-biopsy is the best solution. The significant differences in NT size between biopsies and surgical specimens highlight the importance of assessing NT diameter in all tissue samples examined.

Scientific evolution from the definition of Hirschsprung disease to the present: a bibliometric analysis (1980-2023)

BACKGROUND

The primary objective of this study is to define the global productivity of Hirschsprung disease (HSCR), identify influential studies, determine research directions focused on both historical and contemporary perspectives.

METHODS

The study obtained 2816 articles published between 1980 and 2023 related to HSCR from the Web of Science database, and comprehensive bibliometric analysis were conducted.

RESULTS

The top three most productive countries were the USA (n = 1283), China (n = 1167), and Japan (n = 587). The most productive institution was Université Paris Cité (n = 149), and the most productive author was Prem Puri (n = 99). The most frequently used keywords in the articles were enterocolitis (n = 191), enteric nervous system (n = 136), and transanal endorectal pull-through (n = 129).

CONCLUSION

Academic interest in HSCR began in 1887-1888, significantly increased in 1948 and 1964, and reached its highest peak in 1994. The findings indicate that key topics such as enterocolitis, enteric nervous system, surgical techniques, and genetic factors have been prominent in HSCR research. Previous studies, which often focused on molecular and genetic mechanisms, have shifted towards clinical and surgical applications in the last decade. Factor analysis reveals the complexity and diversity of HSCR research, with various topics examined, including clinical features, surgical treatments, pathological findings, and genetic bases.

IMPACT STATEMENT

This study presents a comprehensive bibliometric analysis of global research trends and future directions in Hirschsprung disease, revealing significant changes and developments in the study of the disease. The study provides an important contribution to the existing literature by detailing the historical development, main research topics, and thematic evolution of Hirschsprung disease research. The findings indicate that future research focus in Hirschsprung disease may increasingly prioritize innovative approaches, such as stem cell therapy, alongside clinical and surgical advancements. These advancements have the potential to enhance patient quality of life and guide future research strategies.

The Future of Surgical Diagnostics: Artificial Intelligence-Enhanced Detection of Ganglion Cells for Hirschsprung Disease

Hirschsprung disease, a congenital disease characterized by the absence of ganglion cells, presents significant surgical challenges. Addressing a critical gap in intraoperative diagnostics, we introduce transformative artificial intelligence approach that significantly enhances the detection of ganglion cells in frozen sections. The data set comprises 366 frozen and 302 formalin-fixed-paraffin-embedded hematoxylin and eosin-stained slides obtained from 164 patients from 3 centers. The ganglion cells were annotated on the whole-slide images (WSIs) using bounding boxes. Tissue regions within WSIs were segmented and split into patches of 2000 × 2000 pixels. A deep learning pipeline utilizing ResNet-50 model for feature extraction and gradient-weighted class activation mapping algorithm to generate heatmaps for ganglion cell localization was employed. The binary classification performance of the model was evaluated on independent test cohorts. In the multireader study, 10 pathologists assessed 50 frozen WSIs, with 25 slides containing ganglion cells, and 25 slides without. In the first phase of the study, pathologists evaluated the slides as a routine practice. After a 2-week washout period, pathologists re-evaluated the same WSIs along with the 4 patches with the highest probability of containing ganglion cells. The proposed deep learning approach achieved an accuracy of 91.3%, 92.8%, and 90.1% in detecting ganglion cells within WSIs in the test data set obtained from centers. In the reader study, on average, the pathologists' diagnostic accuracy increased from 77% to 85.8% with the model's heatmap support, whereas the diagnosis time decreased from an average of 139.7 to 70.5 seconds. Notably, when applied in real-world settings with a group of pathologists, our model's integration brought about substantial improvement in diagnosis precision and reduced the time required for diagnoses by half. This notable advance in artificial intelligence-driven diagnostics not only sets a new standard for surgical decision making in Hirschsprung disease but also creates opportunities for its wider implementation in various clinical settings, highlighting its pivotal role in enhancing the efficacy and accuracy of frozen sections analyses.

Postoperative Hirschsprung's associated enterocolitis (HAEC): transition zone as putative histopathological predictive factor

AIMS

Hirschsprung's-associated enterocolitis (HAEC) is the most severe complication of Hirschsprung disease (HD), and its pathogenesis is still unknown. Length of transition zone (TZ) interposed between aganglionic and normal bowel has been poorly explored as predictor for postoperative HAEC (post-HAEC). This study aimed to identify potential predictive factors for post-HAEC, with a particular focus on histopathological findings.

METHODS

Data from Hirschsprung patients treated in a single Italian centre between 2010 and 2022 with a follow-up >6 months were collected. Thorough histopathological examination of the resected bowel was conducted, focusing on length of TZ and aganglionic bowel.The degree of inflammatory changes in ganglionic resected bowel was further obtained. Ultra-long HD, total colonic aganglionosis and ultra-short HD were excluded. Bivariate and multivariate regression analysis were performed.

RESULTS

Thirty-one patients were included; 5 experienced preoperative HAEC (pre-HAEC) and later post-HAEC (16.1%), further 10 patients developed post-HAEC (total post-HAEC 48.38%). Pre-HAEC-history and a TZ<2.25 cm correlated with an early development of post-HAEC. Multivariate analysis identified a TZ<2.25 cm as an independent post-HAEC predictive factor (p=0.0096). Inflammation within the ganglionic zone and a TZ<2.25 cm correlated with higher risk of post-HAEC (p=0.0074, 0.001, respectively). Severe post-HAEC more frequently occurred in patients with pre-HAEC (p=0.011), histological inflammation (p=0.0009) and short TZ (p=0.0015).

CONCLUSIONS

This study suggests that TZ<2.25 cm predicts the risk of post-HAEC. Preoperative clinical and histopathology inflammation may predispose to worst post-HAEC. Readily available histopathological findings might help identifying patients at higher risk for HAEC and implementing prevention strategies.

Treatment of Persistent Soiling in Hirschsprung Disease With Antegrade Continence Enemas

INTRODUCTION

Patients with Hirschsprung disease (HD) can experience soiling after their pull-through. We evaluated the use of antegrade continence enema (ACE) for this patient population and investigated the timing and factors associated with getting the patient clean.

METHODS

We performed a single-institution retrospective review (from January 2020 to January 2023) of patients with HD and prior pull-through who had persistent soiling, failed laxative treatment or rectal enemas, and were treated with antegrade enemas. The primary outcome was time to become "clean of stool" which was defined as at least one bowel movement per day, no more than one stool accident per week, and no significant stool burden radiographically. Kaplan-Meier survival analysis was performed, and univariate cox proportional hazard regression was used to assess factors associated with time to continence.

RESULTS

Thirty patients who met the criteria underwent ACE creation at a median age of 6.5 y (interquartile range 5.3-9.8) with a median follow-up time of 11.5 mo (interquartile range 5.6-16.5). Most patients became clean by 4 mo (13 of 20, 65%) with similar results at 1-y follow-up (16 of 21, 76%). The median time to becoming clean was 4.3 mo (95% confidence interval: 1.7-15.0. Patients with hypermotility were more likely to continue to soil at 1 y (80% versus 13%, P = 0.01). There were no additional factors significantly associated with time to cleanliness.

CONCLUSIONS

ACE is a useful modality for HD patients with soiling. Most became clean of stool in 4 mo. The presence of hypermotility was associated with a higher incidence of persistent soiling at 1 y.

Can the diameter of nerve fibers be effectively utilized to enhance the accuracy of determining the length of the aganglionic segment compared to intraoperative biopsy in patients with Hirschsprung's disease?

OBJECTIVE

The aim of this study is to investigate the accuracy of utilizing neural fiber trunk diameter in accurately diagnosing the length of the aganglionic segment in patients definitively diagnosed with Hirschsprung's disease.

RESULTS

In this study, 40 patients (19 males, 21 females; mean age 2.5 ± 2.2646 years) were assessed for Hirschsprung's disease. Constipation was the main symptom (75%), followed by abdominal issues. All underwent contrast enema and rectal suction biopsy for diagnosis, followed by surgery (predominantly Soave and Swensen techniques). Majority (85%) had rectosigmoid involvement. Neural fiber diameter was measured, with 52.5% ≤40 μm and 47.5% >40 μm. Statistical analysis showed 40% sensitivity(CI:95%) and 47% specificity(CI:95%) with a cutoff of 40.5 μm. Cohen's kappa index for aganglionic segment size was 0.7.

Hirschsprung's disease. Management

BACKGROUND

Hirschsprung's disease (HD) is a rare congenital disease that is characterised by the absence of ganglion cells in the myenteric plexus starting in the distal bowel. This results in distal functional obstruction and may lead to complications like enterocolitis. The treatment is surgical and requires the resection of the aganglionic segment, and the pull-through of normal intestine into the anal opening. However, even after successful surgery, patients may continue to have symptoms.

AIM

Discuss current surgical techniques and management strategies for patients with postoperative symptoms after surgical correction of Hirschsprung's disease.

METHODS

A review of the literature was done through PubMed, with a focus on clinical management and approach.

RESULTS

We describe the clinical problems that can occur after surgical correction. These include obstructive symptoms, enterocolitis, or faecal incontinence. A systematic approach for the evaluation of these patients includes the exclusion of anatomic, inflammatory, behavioural or motility related factors. Depending on the severity of the symptoms, the evaluation includes examination under anaesthesia, the performance of contrast studies, endoscopic studies, measurement of anal sphincter function and colonic motility studies. The treatment is focused towards addressing the different pathophysiological mechanisms, and may include medical management, botulinum toxin to the anal sphincter or rarely redo-operation.

CONCLUSIONS

Patients with Hirschsprung's disease need to have surgical correction, and their postoperative long-term management is complex given a variety of associated problems that can occur after surgery. A systematic evaluation is necessary to provide appropriate therapy.

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

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

Virtual Staining of Nonfixed Tissue Histology

Surgical pathology workflow involves multiple labor-intensive steps, such as tissue removal, fixation, embedding, sectioning, staining, and microscopic examination. This process is time-consuming and costly and requires skilled technicians. In certain clinical scenarios, such as intraoperative consultations, there is a need for faster histologic evaluation to provide real-time surgical guidance. Currently, frozen section techniques involving hematoxylin and eosin (H&E) staining are used for intraoperative pathology consultations. However, these techniques have limitations, including a turnaround time of 20 to 30 minutes, staining artifacts, and potential tissue loss, negatively impacting accurate diagnosis. To address these challenges, researchers are exploring alternative optical imaging modalities for rapid microscopic tissue imaging. These modalities differ in optical characteristics, tissue preparation requirements, imaging equipment, and output image quality and format. Some of these imaging methods have been combined with computational algorithms to generate H&E-like images, which could greatly facilitate their adoption by pathologists. Here, we provide a comprehensive, organ-specific review of the latest advancements in emerging imaging modalities applied to nonfixed human tissue. We focused on studies that generated H&E-like images evaluated by pathologists. By presenting up-to-date research progress and clinical utility, this review serves as a valuable resource for scholars and clinicians, covering some of the major technical developments in this rapidly evolving field. It also offers insights into the potential benefits and drawbacks of alternative imaging modalities and their implications for improving patient care.

Establishment and identification of an animal model of Hirschsprung disease in suckling mice

BACKGROUND

Hirschsprung disease (HSCR) is a congenital intestinal malformation. Previous HSCR animal model needs invasive operation on adult animal. The aim of this study is to establish an early-onset animal model which is consistent with the clinical manifestation of HSCR patients.

METHODS

The neonatal mice were randomly divided into the benzalkonium chloride (BAC) group, treated with BAC via enema, and the control group, treated with saline. Weight changes, excretion time of carmine, CT scan, hematoxylin-eosin staining and immunofluorescence staining were used to evaluate the effect of the model. Differentially expressed genes (DEGs) in the HSCR mice were analyzed by using DAVID 6.8 database and compared with DEGs from HSCR patients.

RESULTS

The weight of mice was lower and the excretion time of carmine was longer in the BAC group. Moreover, distal colon stenosis and proximal colon enlargement appeared in the BAC group. Neurons in the distal colon decreased significantly after 4 weeks of BAC treatment and almost disappeared completely after 12 weeks. Transcriptome profiling of the mouse model and HSCR patients is similar in terms of altered gene expression.

CONCLUSIONS

An economical and reliable HSCR animal model which has similar clinical characteristics to HSCR patients was successfully established.

IMPACT

The animal model of Hirschsprung disease was first established in BALB/c mice. This model is an animal model of early-onset HSCR that is easy to operate and consistent with clinical manifestations. Transcriptome profiling of the mouse model and HSCR patients is similar in terms of altered gene expression.

Hirschsprung disease

Hirschsprung disease (HSCR) is a rare congenital intestinal disease that occurs in 1 in 5,000 live births. HSCR is characterized by the absence of ganglion cells in the myenteric and submucosal plexuses of the intestine. Most patients present during the neonatal period with the first meconium passage delayed beyond 24 h, abdominal distension and vomiting. Syndromes associated with HSCR include trisomy 21, Mowat-Wilson syndrome, congenital central hypoventilation syndrome, Shah-Waardenburg syndrome and cartilage-hair hypoplasia. Multiple putative genes are involved in familial and isolated HSCR, of which the most common are the RET proto-oncogene and EDNRB. Diagnosis consists of visualization of a transition zone on contrast enema and confirmation via rectal biopsy. HSCR is typically managed by surgical removal of the aganglionic bowel and reconstruction of the intestinal tract by connecting the normally innervated bowel down to the anus while preserving normal sphincter function. Several procedures, namely Swenson, Soave and Duhamel procedures, can be undertaken and may include a laparoscopically assisted approach. Short-term and long-term comorbidities include persistent obstructive symptoms, enterocolitis and soiling. Continued research and innovation to better understand disease mechanisms holds promise for developing novel techniques for diagnosis and therapy, and improving outcomes in patients.

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.

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.

Hirschsprung Disease for the Practicing Surgical Pathologist

OBJECTIVES

Hirschsprung disease (HD) is a congenital condition defined by the absence of ganglion cells in the distal-most portion of the gastrointestinal tract. Biopsies and resections for HD can be adrenaline inducing for the general surgical pathologist because specimens are infrequent; HD is 1 of only a few neuroanatomic diseases that general surgical pathologists diagnose; numerous preanalytic factors (eg, biopsy adequacy, surgeon sampling protocol, processing artifacts) can affect histologic interpretation; and most importantly, the diagnosis has high stakes.

METHODS

We provide a comprehensive overview of the background, relevant clinical procedures, and pathologic assessment of HD. Grossing and frozen section protocols, an algorithmic approach to diagnosis, and histologic pearls and pitfalls are also discussed.

RESULTS

Evaluation and recognition of the features of HD have evolved significantly in the past 2 decades with the discovery of the value of calretinin immunohistochemistry in the late 2000s and the recent development of straightforward and reproducible histologic criteria for identification of the HD transition zone.

CONCLUSIONS

These advancements have substantially improved the pathologist's ability to reliably evaluate for HD. Nonetheless, as with any high-stakes surgical pathology specimen, clear communication with the clinical team is essential.

Reconstructing the anal sphincters to reverse iatrogenic overstretching following a pull-through for Hirschsprung disease. One-year outcomes

BACKGROUND

In patients with Hirschsprung disease (HSCR), soiling may be related to anal sphincter damage following the initial pull-through. No optimal treatment has been developed for such patients, although enemas (rectal or antegrade) have been applied with some success. We present the one-year outcomes of a new technique for anal sphincter reconstruction.

METHODS

All patients with HSCR referred from other institutions for post pull-through soiling were studied. Seven patients with patulous sphincters underwent sphincter reconstruction. Six had a full preoperative evaluation and were included in the study. Their 12-month outcomes were assessed.

RESULTS

All six patients had soiling without voluntary bowel movements (VBMs). One patient was clean on Malone flushes when referred. Three underwent pre- and post-reconstruction non-sedated three-dimensional anorectal manometry, and objectively were able to close their sphincters following the reconstruction. All patients without Down syndrome (4 of 6) showed improvement in the abbreviated Baylor Continence Scale (4.5 vs. 0.75). One patient has achieved total bowel control without antegrade flushes, three now have VBMs which they did not have before but have occasional accidents and use antegrade flushes intermittently. They reported higher productivity, the ability to participate in sports and be away from home with confidence in their regimen. Two of 6 patients have Down syndrome and required a redo pull-through for other indications and underwent empiric sphincter reconstruction. For these two patients we do not have an outcomes assessment.

CONCLUSIONS

A new technique for sphincter reconstruction shows promising results in improvement of bowel control at one year.

LEVEL OF EVIDENCE

IV.

The role of stomas in the initial and long-term management of Hirschsprung disease

AIM

To review the role of stomas in the initial and long-term management of Hirschsprung disease (HD).

METHODS

Patients treated for HD at our institution between January 2004 and August 2021 were identified. Data were collected regarding: demographics, indication/bowel location/type of stomas performed and outcomes, pull-through (PT) procedure, and follow-up duration.

RESULTS

Ninety-five patients (78 male) were identified including one early unrelated death. Forty-four of 94 (47%) required a stoma before PT procedure. Of these 44, 38 (86%) had ileostomies and the remaining six (14%) colostomies; one ileostomy remains long-term. The commonest indication for initial stomas was washout failure (41%). Ninety-one patients had undergone primary PT or secondary PT with stoma closure at the time of the study. A further new stoma was required after primary PT or three-stage management in 20/91 (22%). The commonest indications were constipation/soiling (25%) and anastomotic leak (20%). Seven out of 20 (35%) were performed within 30 days of a previous procedure and all were closed; three patients required further long-term stomas. Thirteen (65%) required a stoma >30 days, nine remain long-term. Surgical revision of stomas was required in 14/56 (25%) - prolapse and retraction being the commonest indications. Overall, 56/94 (60%) patients required stomas (pre- and/or post-PT) to manage their condition and 13/94 (14%) have a long-term stoma in place. Mean follow-up was 7.8 years (0.5 - 17.6).

CONCLUSIONS

Stomas remain an integral part of HD management both initially (47%) and long-term (14%); they carry a considerable associated morbidity. Ileostomy is preferred for initial management.

LEVEL OF EVIDENCE

Level III.

The transition zone in Hirschsprung's bowel contains abnormal hybrid ganglia with characteristics of extrinsic nerves

The aganglionic bowel in short-segment Hirschsprung's disease is characterized both by the absence of enteric ganglia and the presence of extrinsic thickened nerve bundles (TNBs). The relationship between the TNBs and the loss of enteric ganglia is unknown. Previous studies have described decreasing numbers of ganglia with increasing density of TNBs within the transition zone (TZ) between ganglionic and aganglionic gut, and there is some evidence of spatial contact between them in this region. To determine the cellular interactions involved, we have analysed the expression of perineurial markers of TNBs and enteric ganglionic markers for both neural cells and their ensheathing telocytes across four cranio-caudal segments consisting of most proximal ganglionic to most distal aganglionic from pull-through resected colon. We show that in the TZ, enteric ganglia are abnormal, being surrounded by perineurium cells characteristic of TNBs. Furthermore, short processes of ganglionic neurons extend caudally towards the aganglionic region, where telocytes in the TNB are located between the perineurium and nerve fibres into which they project telopodes. Thus, enteric ganglia within the TZ have abnormal structural characteristics, the cellular relationships of which are shared by the TNBs. These findings will help towards elucidation of the cellular mechanisms involved in the aetiology of Hirschsprung's disease.

Calretinin Staining in Anorectal Line Biopsies Accurately Distinguished Hirschsprung Disease in a Retrospective Study

INTRODUCTION

The absence of submucosal ganglion cells does not reliably distinguish Hirschsprung disease from non Hirschsprung disease in anorectal line biopsies. Calretinin staining might be helpful in these biopsies. To determine its value, we analyzed calretinin positive mucosal neurites in anorectal line biopsies.

METHODS

Two pediatric pathologists, without access to patient data, evaluated calretinin positive mucosal neurites in anorectal line junctional mucosa in archival rectal biopsies contributed by 17 institutions. A separate investigator compiled patient information and sent data for statistical analysis.

RESULTS

Biopsies with anorectal junctional mucosa from 115 patients were evaluated for calretinin positive mucosal neurites. 20/20 Hirschsprung disease biopsies were negative. 87/88 non Hirschsprung disease biopsies and 7/7 post pullthrough Hirschsprung disease neorectal biopsies were positive. Statistical analysis of the 108 non pullthrough biopsies yielded an accuracy of 99.1% (sensitivity 100%, specificity 98.9%). Age range was preterm to 16 years. Biopsy size was less than 1 mm to over 1 cm.

CONCLUSIONS

Absence of calretinin positive mucosal neurites at the anorectal line was highly accurate in distinguishing Hirschsprung disease from non Hirschsprung disease cases in this blinded retrospective study. Calretinin staining is useful for interpreting biopsies from the physiologic hypoganglionic zone up to the anorectal line.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

TYPE OF STUDY

clinical research paper.

Total Colonic Aganglionosis in Hirschsprung disease

Total Colonic Hirschsprung Disease (HD) can be challenging from a diagnostic and management standpoint and occurs in around 8% of cases of HD. Long term outcomes are difficult to compare due to variation in length of aganglionosis, chosen surgical techniques, and terminology utilized in the literature. In this review we highlight some of the management controversies and clinical challenges and emphasize future areas of suggested collaboration and research.

Hirschsprung's Disease in Adults Revealed by an Occlusive Syndrome

Hirschsprung's disease (HD) in adults is rare, occurring before the age of five years in 90% of cases. It is characterized by the absence of ganglion cells in a colorectal segment, resulting in functional obstruction and an upstream colonic dilatation.

HD should be considered in front of any history of chronic constipation. The diagnosis is based on a combination of clinical, manometric, radiological, and histological findings. Surgery is the basis of the treatment and consists of the resection of the aganglionic segment, followed by restoration of continuity between the two healthy segments.

We report here the case of a 20-year-old man who presented to the ER with an occlusive syndrome, which initially required a loop colostomy for decompression. History, clinical presentation, and radiological findings were suggestive of HD, but additional diagnostic methods including manometry and biopsy were employed but proved negative. Given the available data, the patient underwent a colectomy with a latero-terminal ileorectal anastomosis. Histological findings of the surgical specimen confirmed the diagnosis of HD.

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.

Neurons populating the rectal extrinsic nerves in humans express neuronal and Schwann cell markers

BACKGROUND

In mice, Schwann cell (SC) progenitors give rise to autonomic ganglion cells and migrate into the gut to become enteric neurons. It is unknown whether SC progenitors have a similar fate in humans. In search of evidence for human SC-derived neurogenesis in the gastrointestinal (GI) tract, we studied the rectums from cadaveric controls and children with anorectal malformations (ARM).

METHODS

We analyzed distal rectal tissue taken at autopsy from 10 children with normal GI tracts and resected rectal specimens in 48 cases of ARM. Of these specimens, 6 had neurons within the extrinsic rectal innervation. These were further investigated with immunohistochemistry for neuronal and SC/glial markers.

KEY RESULTS

Perirectal tissue from control and ARM contained GLUT1-positive extrinsic nerves, many containing neurons. SC/glial markers (SOX10, CDH19, and PLP1) were expressed by glia in the enteric nervous system and perirectal nerves, while MPZ predominated only in glia of perirectal nerves, in both control and ARM. Neurons in perirectal nerves were 61% larger in ARM samples and co-expressed SOX10 (81%), PLP1 (73%), and CDH19 (56%). In ARM, cytoplasmic SOX10 was co-expressed with neuronal antigens in ~57% of submucosal and myenteric neurons, vs. ~3% in control. Furthermore, intrinsic gut neurons in ARM specimens co-expressed PLP1 (18%) and CDH19 (18%); however, neuronal co-expression of PLP1 and CDH19 was rarely (<2%) observed in controls.

CONCLUSIONS & INFERENCES

Dual expression of glial and neuronal markers in rectal and perirectal neurons support a model of Schwann cell-derived neurogenesis in the innervation of the human GI tract.

PHOX2B Immunostaining: A Simple and Helpful Tool for the Recognition of Ganglionic Cells and Diagnosis of Hirschsprung Disease

Hirschsprung disease (HD) is a congenital disorder of the enteric nervous system that occurs in ∼1 in 5000 live births. It is characterized by the absence of ganglionic cells (GCs) in the distal intestine. The diagnosis relies on the thorough analysis of a rectal suction biopsy (RSB), which must show a complete absence of GCs after careful examination of at least 100 serial sections. Such a negative characteristic explains the difficulty of this diagnosis. Moreover, GCs may be immature in very young or preterm born children, making them hard to recognize. Therefore, ancillary techniques have been developed as diagnostic help, such as acetylcholinesterase histochemistry and calretinin immunostaining. These techniques reveal only indirect clues, focusing mainly on the changes in nerve fibers, but not on GCs themselves. As PHOX2B has been shown to be a very specific transcription factor in GCs and in progenitor enteric nerve cells, we have assessed (i) PHOX2B immunostaining in immature enteric ganglia and (ii) the use of PHOX2B immunostaining for the recognition of GCs on RSBs for suspicion of HD. We have observed PHOX2B expression in all GCs, both mature and immature, and its complete absence in Hirschsprung cases. We suggest that the use of PHOX2B immunostaining is of great help (i) in the recognition of GCs on RSBs regardless of their differentiation and therefore (ii) in the diagnosis of HD.

Advances and Pitfalls in the Diagnosis of Hirschsprung Disease

Surgical pathology for Hirschsprung disease (HSCR) occasionally is difficult, especially for those who encounter the disorder infrequently. This article reviews pathologic features of HSCR, considers various specimens the pathologist is required to evaluate, and discusses useful ancillary tests. Potential diagnostic pitfalls are highlighted, and helpful hints are provided to successfully navigate challenging situations. Finally, the article looks forward to new ancillary tests on the horizon and future topics for HSCR research.