Variant Hirschsprung's disease

A novel mouse model of intestinal neuronal dysplasia: visualization of the enteric nervous system

PURPOSE

Intestinal neuronal dysplasia (IND) is a congenital anomaly affecting gastrointestinal neural innervation, but the pathogenesis remains unclear. The homozygous Ncx/Hox11L.1 knockout (Ncx-/-) mice exhibit megacolon and enteric ganglia anomalies, resembling IND phenotypes. Sox10-Venus transgenic mouse were used to visualize enteric neural crest cells in real time. This study aims to establish a novel mouse model of Sox10-Venus+/Ncx-/- mouse to study the pathogenesis of IND.

METHODS

Sox10-Venus+/Ncx-/- (Ncx-/-) (n = 8) mice and Sox10-Venus+/Ncx+/+ controls (control) (n = 8) were euthanized at 4-5 weeks old, and excised intestines were examined with fluorescence microscopy. Immunohistochemistry was performed on tissue sections with neural marker Tuj1.

RESULTS

Ncx-/- mice exhibited dilated cecum and small intestine. Body weight of Ncx-/- mice was lower with higher ratio of small intestine length relative to body weight. The neural network (Sox10-Venus) was observed along the intestine wall in Ncx-/- and control mice without staining. Ectopic and increased expression of Tuj1 was observed in both small intestine and proximal colon of Ncx-/- mice.

CONCLUSION

This study has established a reliable animal model that exhibits characteristics similar to patients with IND. This novel mouse model can allow the easy visualization of ENS in a time- and cost-effective way to study the pathogenesis of IND.

Translational research in Hirschprung's disease at the National Children's Research Centre in Dublin

Hirschsprung's disease (HD) is a congenital condition characterised by aganglionosis in the distal bowel. Over the years, at the National Children's Research Centre (NCRC), HD has been one of the most prominent and successful research areas for Prof. Prem Puri's research team. Research fellows from around the world came to the NCRC to work on both animal and human studies of HD and, cumulatively, made important discoveries in this field, publishing a total of 144 HD articles in peer-reviewed journals. Through their published work, the NCRC has been recognised as the leading international centre for the investigation of HD and its allied disorders. In this review, I will summarise the main findings from this work.

Outcome of Santulli enterostomy in patients with immaturity of ganglia: single institutional experience from a case series

Background

Immaturity of ganglia (IG) is an extremely rare disease and always requires surgical intervention in the neonatal period, but without guidelines to choose the ideal enterostomy procedure, the timing of stoma closure remains controversial. The aim of this study was to report our experience using Santulli enterostomy for the treatment of nine infants diagnosed with IG.

Methods

Patients who underwent Santulli enterostomy and were diagnosed with IG in our center between 2016 and 2021 were retrospectively studied. Temporary stoma occlusion and a 24-h delayed film of barium enema (BE) were performed to evaluate intestinal peristalsis function to determine the timing of stoma closure. The demographic data, clinical and radiological findings, stoma occlusion and stoma closure results were explored.

Results

A total of 9 infants underwent Santulli enterostomy and were diagnosed with IG postoperatively. Their median gestational age at birth was 36 weeks (range 31–42), and their median birth weight was 2765 g (range 1300–3400). All patients had symptom onset in the neonatal period, including abdominal distension and biliary vomiting. Eight patients showed obvious small bowel dilatation in the plain films, except for one patient’s films that suggested gastrointestinal perforation with free gas downstream of the diaphragm. BE was performed in 6 patients, all of which had microcolons. The median age at operation was 3 days (range 1–23). Seven patients had an obvious transitional zone (TZ) during laparotomy, and the position of the TZ was 25–100 cm proximal above the ileocecal (IC) valve. Immature ganglion cells were present in the colon in 7 patients and the terminal ileum in 6 patients. The median age of successful stoma occlusion was 5 M (range 2–17) and 8 M (range 4–22) at ostomy closure. There was little or no barium residue in the 24-h delayed film of BE before stoma closure, and all patients were free of constipation symptoms during the follow-up.

Conclusion

Santulli enterostomy appears to be a suitable and efficient procedure for IG, combined with temporary stoma occlusion and 24-h delayed film of BE to evaluate the recovery of intestinal peristalsis function.

Palisading-like arrangement of immature ganglion cell in myenteric ganglia is a unique pathological feature of immaturity of ganglia

BACKGROUND

Immaturity of ganglia (IG), an allied disorder of Hirschsprung disease (AD-HSCR), develops as neonatal ileus, but the dysmotility spontaneously resolves after several months. The diagnosis of IG using HE staining is often difficult. We herein report a new pathological finding of IG called the 'palisading-like pattern', which may be helpful for improving the diagnostic accuracy.

METHODS

Cases of IG that were managed over the past 28 years were retrospectively reviewed. We investigated the clinical course and pathological findings for Hematoxylin-Eosin (HE) staining. The conventional diagnostic criteria for IG were (1) a normal or slightly increased number of ganglion cells and (2) ganglion cells with small nuclei.

RESULTS

Among the 155 cases, 28 were diagnosed with IG, and 10 were retrospectively confirmed by HE staining. A palisading-like pattern was confirmed at the time of the initial ileostomy (median age, 2.5 days), and the palisading-like pattern had completely disappeared by the time of stoma closure (median age, 215 days) in all 10 cases. A palisading-like pattern is not present in other diseases.

CONCLUSIONS

Even if immunostaining data are not available for a further analysis, the detection of a palisading-like pattern on HE staining makes an accurate diagnosis possible.

LEVEL OF EVIDENCE

LEVEL IV.

Comparison of clinical features and prognosis between ultrashort-segment and short-segment hirschsprung disease

OBJECTIVE

To compare the differences in clinical features, postoperative complications, and long-term bowel function outcomes of ultrashort-segment Hirschsprung disease (USHD) and short-segment Hirschsprung disease (SHD).

METHODS

A retrospective study was conducted to compare patients with USHD or SHD who underwent transanal endorectal pull-through (TEPT) at Beijing Children's Hospital between January 2014 and June 2021. Clinical details were collected from medical records. A long-term bowel function questionnaire (age > 4 years old) was completed by the patients' parents.

RESULTS

A total of 84 patients (USHD = 15, SHD = 69) were included. Age at diagnosis and radical surgery in the USHD group were significantly older than the SHD group (46 [38, 66] vs. 34 [6, 55] months, p = 0.002; 51 [39, 68] vs. 37 [10, 68] months, p = 0.001, respectively). Compared with the SHD group, patients with USHD are more likely to suffer anastomosis leakage and postoperative enterocolitis after TEPT ([3/15, 33.3%] vs. [1/69, 1.4%], p = 0.017; [5/15, 33.3%] vs. [6/69, 8.7%], p = 0.023). In addition, patients in the USHD group are inclined to suffer lower bowel function scores (12.0 [7.5, 18.3] vs. 17 [15, 19], p = 0.018).Patients in the USHD group were more likely to suffer poorer ability to hold back defecation (p = 0.023), soiling (p = 0.011), fecal accidents (p = 0.004), and social problems (p = 0.004).

CONCLUSION

Compared with patients with SHD, patients with USHD are diagnosed and performed TEPT at an older age. and they are inclined to suffer postoperative enterocolitis, anastomosis leakage, and poorer long-term bowel function following TEPT.

Efficacy of Sox10 Promoter Methylation in the Diagnosis of Intestinal Neuronal Dysplasia From the Peripheral Blood

OBJECTIVES

Intestinal neuronal dysplasia (IND) is a common malformation of the enteric nervous system. Diagnosis requires a full-thickness colonic specimen and an experienced pathologist, emphasizing the need for noninvasive analytical methods. Recently, the methylation level of the Sox10 promoter has been found to be critical for enteric nervous system development. However, whether it can be used for diagnostic purposes in IND is unclear.

METHODS

Blood and colon specimens were collected from 32 patients with IND, 60 patients with Hirschsprung disease (HD), and 60 controls. Sox10 promoter methylation in the blood and the Sox10 expression level in the colon were determined, and their correlation was analyzed. The diagnostic efficacy of blood Sox10 promoter methylation was analyzed by receiver operating characteristic curve.

RESULTS

The blood level of Sox10 promoter methylation at the 32nd locus was 100% (90%-100%; 95% confidence interval [CI], 92.29%-96.37%) in control, 90% (80%-90%; 95% CI, 82.84%-87.83%) in HD, and 60% (50%-80%; 95% CI, 57.12%-69.76%) in IND specimens. Sox10 promoter methylation in the peripheral blood was negatively correlated with Sox10 expression in the colon, which was low in control, moderate in HD, and high in IND specimens (r = -0.89). The area under the curve of Sox10 promoter methylation in the diagnosis of IND was 0.94 (95% CI, 0.874-1.000, P = 0.000), with a cutoff value of 85% (sensitivity, 90.6%; specificity, 95.0%). By applying a cutoff value of 65%, promoter methylation was more indicative of IND than HD.

DISCUSSION

The analysis of Sox10 promoter methylation in the peripheral blood can be used as a noninvasive method for IND diagnosis.

Recurrent ACTG2 gene variation in African degenerative visceral leiomyopathy

INTRODUCTION

Visceral myopathies remain difficult and frustrating clinical entities, a distinctive form of acquired degenerative visceral myopathy, African degenerative leiomyopathy, a myogenic functional intestinal obstruction without aganglionosis which affects smooth muscle of the intestine, in young indigenous African children. The Actin G2 gene is the main gene encoding smooth muscle actin found in enteric tissues. Recent research has identified Actin G2 alpha gene variation as an important causative biomarker in visceral myopathies and megacystis microcolon. This study of the Actin G2 gene (ACTG2) in an African population explores a possible molecular basis abnormal muscle function in a visceral myopathy.

PATIENTS AND METHODS

Following ethical permission and informed consent, DNA was extracted from whole blood samples in five patients with histologically proven African degenerative leiomyopathy. PCR amplification of ACTG2 alpha gene products by semi-automated bi-directional sequencing analysis. Results were analysed using FinchTV Sequence Alignment Software and predicting bioinformatic investigation by PolyPhen 2 software.

RESULTS

Five new patients with the ADL phenotypes were prospectively investigated for variation in the Actin G2 gamma gene (ACTG2). ACTG2 gene variation occurred in exon 5 (c.463 A>G K119R), in three (60%). In addition, intronic variation t > c-IVS3 was identified in three with the K119 mutation plus further g >  c -IVS12 and t > c + IVS16(2), suggesting a possible haplotype. Bioinformatic modelling showed that these ACTG2 gene variations are highly non-conservative altering protein expression.

CONCLUSIONS

Recurrent Actin G2 smooth muscle gene variation in African degenerative visceral leiomyopathy is associated with abnormal muscle actin development.

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

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

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

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

Introduction

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

Presentation of a case

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

Discussion

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

Conclusion

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

Abundance and Significance of Neuroligin-1 and Neurexin II in the Enteric Nervous System of Embryonic Rats

Aim. To investigate the abundance of neuroligin-1 and neurexin II in the enteric nervous system (ENS) of rats on different embryonic days and to explore their potential significance. Methods. The full-thickness colon specimens proximal to the ileocecal junction of rats on embryonic days 16, 18, and 20 and of newborns within 24 hours (E16, E18, E20, and Ep0) were studied, respectively. qRT-PCR was applied for detecting the expressions of neuroligin-1 and neurexin II on mRNA, and western blotting was employed for detecting their further expressions on the whole tissue. Finally, the histological appearance of neuroligin-1 and neurexin IIα was elucidated using immunohistochemical staining. Results. qRT-PCR showed that the neuroligin-1 and neurexin II mRNA expressions of groups E16, E18, E20, and Ep0 increased gradually with the growth of embryonic rats (P < 0.05). Western blotting confirmed the increasing tendency. In immunohistochemical staining, proteins neuroligin-1 and neurexin IIα positive cells concentrated mostly in the myenteric nerve plexus of the colon and their expressions depend on the embryonic time. Conclusion. Neuroligin-1 and neurexin II were both expressed in the ENS and have temporal correlation with the development of ENS, during which neuronal intestinal malformations (NIM) may occur due to their disruptions and consequent abnormal ENS development.

Long-term outcome of neonates with suspected Hirschsprung's disease, but normal rectal biopsy

BACKGROUND AND OBJECTIVES

Hirschsprung's disease (HD) must always be considered in very early-onset constipation. Although HD has a well-described clinical course, little is known about those neonates in whom HD was excluded. We aimed to describe the long-term clinical outcomes of neonates with a clinical suspicion of HD that was excluded by rectal suction biopsy.

METHODS

This is a single-center double-cohort comparative study. Neonates who underwent rectal mucosa biopsy for suspected HD were age and sex matched with healthy controls. A survey on clinical outcomes, stooling patterns, and other gastrointestinal (GI)-related conditions was sent to parents. Pathology slides were re-reported by an experienced histopathologist blinded to the clinical data.

RESULTS

A total of 51 neonates were included [25 cases, 26 controls; 41% males, median time of follow-up 4.25 years (interquartile range 2.7-6.9)]. Nine (36%) of patients in the case group required prolonged laxative use for constipation during the first year of life compared with 0 (0%) controls (P<0.001). This difference was maintained at the end of follow-up, with 5 (20%) versus 0 (0%), respectively (P=0.02). Case neonates were significantly more likely to be hospitalized or to be diagnosed with a chronic GI-related condition than the controls (33 vs. 12%, P=0.01; and 19 vs. 8%, P=0.04, respectively).

CONCLUSION

Neonatal constipation is associated with long-term GI-related disorders and should be considered clinically significant even when the diagnosis of HD is excluded. Neonates with early-onset abnormal stooling patterns should be monitored with adequate pediatrician or pediatric gastroenterologist follow-up.

Isolated intestinal neuronal dysplasia Type B (IND-B) in Japan: results from a nationwide survey

PURPOSE

Intestinal neuronal dysplasia Type B (IND-B) has been proposed to be an allied disorder of Hirschsprung's disease (ADHD). The original histological criteria included hyperganglionosis, giant ganglia, ectopic ganglion cells and an increased AChE activity in the lamina propria. The criteria for IND-B have been gradually revised. The present diagnostic criteria are [1] more than 20 % of the submucosal ganglia contain nine or more ganglion cells and [2] the patient is older than 1 year. To clarify the current status of IND-B in Japan, a nationwide retrospective cohort study was performed.

METHODS

Questionnaires were sent to 161 major institutes of pediatric surgery and gastroenterology in Japan.

RESULTS

A total of 355 cases of ADHD were collected, including 18 cases of IND-B (5 %). Based on original criteria, 13 out of 18 cases were diagnosed as IND-B. However, only four cases met the current criteria. Three of the four patients (75 %) required pull-through operation. All of the patients exhibited giant ganglia and ganglioneuromatosis-like hyperplasia of the myenteric plexus.

CONCLUSIONS

IND-B cases matching the current criteria are thought to be quite rare and they are associated with marked hyperplasia of the myenteric plexus. "True" IND-B is a rare and intractable disease.

Intestinal neuronal dysplasia type B in adults: a controversial entity

Intestinal neuronal dysplasia (IND) is a well-defined entity which raises controversy among authors, described as a congenital malformation of gastrointestinal innervation and caused by dysplastic embryonal development of the enteric nervous system. It is potentially associated with mild and chronic gastrointestinal motility disturbances. IND is rarely reported in adults and especially elderly patients. The present study reports on the case of a 71-year-old man suffering from longstanding idiopathic constipation and who was misdiagnosed for more than 60 years, despite several hospital admissions and a sigmoidectomy in the meantime. On the last admission, the patient presented with megacolon, abdominal pain and X-ray finding of bowel obstruction. Due to massive large bowel dilatation, an exploratory laparotomy failed to reveal any obvious mechanical cause, and a subtotal colectomy and Hartmann's procedure was performed. Bowel continuity was performed 3 months later. Analysis of full-thickness biopsies revealed enlarged myenteric and submucosal neurons as well as an increased number of giant cells and increased acetylcholinesterase activity in the mucosa. The diagnosis of IND was established. The main diagnostic criteria, the underlining pathophysiology and the recommended therapeutic approach of this rare entity are extensively reviewed.

Classification and diagnostic criteria of variants of Hirschsprung's disease

"Variants of Hirschsprung's disease" are conditions that clinically resemble Hirschsprung's disease (HD), despite the presence of ganglion cells in rectal suction biopsies. The diagnosis and management of these patients can be challenging. Specific histological, immunohistochemical and electron microscopic investigations are required to characterize this heterogeneous group of functional bowel disorders. Variants of HD include intestinal neuronal dysplasia, intestinal ganglioneuromatosis, isolated hypoganglionosis, immature ganglia, absence of the argyrophil plexus, internal anal sphincter achalasia and congenital smooth muscle cell disorders such as megacystis microcolon intestinal hypoperistalsis syndrome. This review article systematically classifies variants of HD based on current diagnostic criteria with an additional focus on pathogenesis, epidemiology, clinical presentation, management and outcome.

A new diagnostic scoring system to differentiate Hirschsprung's disease from Hirschsprung's disease-allied disorders in patients with suspected intestinal dysganglionosis

PURPOSE

To create a simple diagnostic scoring system to differentiate Hirschsprung's disease (HD) from Hirschsprung's disease-allied disorders (HAD) in patients with suspected intestinal dysganglionosis (IDs).

METHODS

Between 1998 and 2008, 967 patients with suspected intestinal dysganglionosis underwent surgical treatment at the pediatric surgery department of Tongji Hospital. The diagnosis of HD or HAD was confirmed by postoperative pathological examination. All patients underwent preoperative work-up including barium enema, anorectal manometry, and histochemical acetylcholinesterase staining of rectal mucosa. Known risk factors for IDs were recorded. The predicting score was calculated by summing the scores of the risk factors and three preoperative tests. The sensitivity, specificity, accuracy, positive predictive values, negative predictive values, positive likelihood ratios, and negative likelihood ratios of the predicting score were calculated. The cutoff score for predicting HD was determined using receiver operating characteristic (ROC) analysis. The accuracy of the predicting score was measured by the area under the ROC curve.

RESULTS

Failed or delayed passage of meconium, age <3 years and male gender were risk factors associated with HD. The area under the ROC curve of the predicting score was 0.927 (95 % confidence interval, 0.910-0.944). A predicting score of more than 5 was used as a cutoff for predicting HD. The scoring system achieved 83.1 % sensitivity, 89.5 % specificity, and 85.9 % accuracy in predicting HD.

CONCLUSION

Patients with a predicting score of more than 5 are more likely to be diagnosed with HD, whereas a score less than 5 are mostly indicative of HAD.

RET promoter variations in familial African degenerative leiomyopathy (ADL): first report of a possible genetic-environmental interaction

African degenerative leiomyopathy (ADL, DL, Bantu pseudo-Hirschsprung's disease) is a distinctive visceral myopathy, of unknown etiology, occurring in Africa. It has a classical clinical and histologic picture in young indigenous African children. It presents as intestinal pseudo-obstruction with a massive megacolon due to degeneration of smooth muscle without aganglionosis. Because of its late presentation and geographical and ethnic distribution, it is thought to be an acquired degenerative hollow visceral myopathy. Only one previous report of familial recurrence exists. The main Hirschsprung susceptibility gene RET is a potential candidate gene in this condition, because of its role in the development of the intrinsic innervation and ganglia of the smooth muscle layers of the gastro-intestinal tract. We report a second case of familial ADL recurrence and explore possible etiologic causes including variations of the RET gene. Multiple variations in the RET promoter were identified in this case which leads to the possibility of a genetic-environmental predisposition for this condition. We therefore hypothesize that RET may play a modulating role in ADL susceptibility (and possibly other visceral myopathies). It is possible that subtle malformations in the ENS may result from RET dysfunction which then predisposes the individual to environmental influences which initiate the later onset of muscle degeneration.

Variants of Hirschsprung disease

Variants of Hirschsprung disease are conditions that clinically resemble Hirschsprung disease, despite the presence of ganglion cells in rectal suction biopsies. The characterization and differentiation of various entities are mainly based on histologic, immunohistochemical, and electron microscopy findings of biopsies from patients with functional intestinal obstruction. Intestinal neuronal dysplasia is histologically characterized by hyperganglionosis, giant ganglia, and ectopic ganglion cells. In most intestinal neuronal dysplasia cases, conservative treatments such as laxatives and enema are sufficient. Some patients may require internal sphincter myectomy. Patients with the diagnosis of isolated hypoganglionosis show decreased numbers of nerve cells, decreased plexus area, as well as increased distance between ganglia in rectal biopsies, and resection of the affected segment has been the treatment of choice. The diagnosis of internal anal sphincter achalasia is based on abnormal rectal manometry findings, whereas rectal suction biopsies display presence of ganglion cells as well as normal acetylcholinesterase activity. Internal anal sphincter achalasia is either treated by internal sphincter myectomy or botulinum toxin injection. Megacystis microcolon intestinal hypoperistalsis is a rare condition, and the most severe form of functional intestinal obstruction in the newborn. Megacystis microcolon intestinal hypoperistalsis is characterized by massive abdominal distension caused by a largely dilated nonobstructed bladder, microcolon, and decreased or absent intestinal peristalsis. Although the outcome has improved in recent years, survivors have to be either maintained by total parenteral nutrition or have undergone multivisceral transplant. This review article summarizes the current knowledge of the aforementioned entities of variant HD.

Histochemical staining for intestinal dysganglionosis: over 30 years experience with more than 1,500 biopsies

PURPOSE

Intestinal dysganglionosis are a group of anomalies of the enteric nervous system that constitute infrequent but severe forms of constipation. Histochemical stainings are the gold standard diagnostic procedure for intestinal dysganglionosis. This study describes our experience with histochemistry in a large series of patients.

METHODS

Between 1977 and 2010, 1,589 biopsies from children with persistent chronic constipation were studied. The specimens were snap frozen, sectioned and stained with acetylcholinesterase (AChE), acetylcholinesterase counterstained with hematoxilin and succinic dehydrogenase (SDH) histochemical stainings.

RESULTS

Among the 1,589 biopsies, 946 (59.5%) were rectal biopsies, 242 (15.2%) were internal sphincter biopsies, 346 (21.8%) were intestinal mapping studies and 42 (2.7%) of them were colon specimens from surgical resections. From the rectal biopsy group, 544 (57.5%) patients were reported as normal. Hirschsprung disease was found in 163 (17.2%) patients with a median age at diagnosis of 8 months and a male to female ratio of 3:1. Intestinal neuronal dysplasia was found in 162 (17.2%) patients, hypoganglionosis in 3 (0.3%) of them and ganglioneuromatosis in 1 (0.1%). In 73 (7.7%) patients, the biopsy was not conclusive for different reasons. 34 out of the 42 resected colon specimens were Hirschsprung disease. Intestinal neuronal dysplasia was found in the proximal segment of the aganglionic bowel in 15 out of 34 (44%) patients. All the aganglionic resected colon specimens had a previous aganglionic rectal biopsy. There were no false positive results in this group.

CONCLUSIONS

Histochemical stainings continue to be the gold standard in the diagnosis of intestinal dysganglionosis. The combination of two histochemical staining techniques provides a high level of accuracy in the diagnosis of intestinal dysganglionosis.

Ganglia/nerve fibers ratio correlates with the need for surgery in patients diagnosed with Hirschsprung's disease allied disorder (HAD)

Treatment in Hirschsprung's disease allied disorder (HAD) is surgical. In HAD, surgery is always a question. We investigated the value of ganglia/nerve fibers ratio in prediction of the need for invasive procedures in HAD. Sections of full thickness bowel specimens of 14 patients were stained with antibodies marking ganglia (Anti-Neuron-Specific Enolase, Anti-NSE) and marking nerve fibers (S-100). Six out of seven patients indicated for surgery had low ganglia/nerve fibers ratio. Five out of seven patients, not showing the need for surgery, had high ganglia/nerve fibers ratio. We propose that a lower ganglia/nerve fiber ratio can be used as a predictor of increased need for surgery in HAD.

Isolated hypoganglionosis: systematic review of a rare intestinal innervation defect

PURPOSE

Isolated hypoganglionosis (IH) is rare and resembles Hirschsprung's disease. The diagnosis by suction biopsy is difficult. A full-thickness biopsy is essential. Histological features of IH include sparse, small myenteric ganglia, low acetylcholinesterase activity in the lamina propria, and hypertrophy of muscularis mucosae and circular muscle. This review investigates the epidemiology, symptoms, diagnosis, and outcome of patients with IH.

METHODS

A systematic review, using the keywords "isolated hypoganglionosis" and "intestinal hypoganglionosis" was performed. Publications were reviewed for epidemiology, histological methods, operative procedures, follow-up, and patient's outcome.

RESULTS

Eleven publications from 1978 to 2009 reported 92 patients with IH (69 males and 23 females, age 4.85 years), presenting with constipation or enterocolitis. Diagnosis of IH was made by full-thickness biopsy and AChE staining in 91% of patients with additional staining in 82%; 54 patients had bowel resection and pull-through procedures; 11 patients had ileostomy or colostomy, and 2 had sphincter myectomy. Complications reported were enterocolitis, constipation, and residual disease. Seven patients (8%) died due to enterocolitis or short-bowel complications.

CONCLUSION

This review confirms that diagnosis of IH is only possible by histochemical examination of a full-thickness biopsy. Despite advanced age at diagnosis of IH, epidemiological and clinical data are similar to aganglionosis.

Increased incidence of Hirschsprung's disease in patients with hypoplastic left heart syndrome--a common neural crest-derived etiology?

BACKGROUND

The enteric ganglions and the outflow tract of the heart originate from the neural crest. Impaired migration or differentiation of the neural crest cells causes Hirschsprung's disease (HD) and results in the development of cardiac outflow tract malformations. We hypothesize that the incidence of HD and bowel disorders associated with HD are increased in patients with hypoplastic left heart syndrome (HLHS) including left cardiac outflow tract obstruction.

METHODS

All consecutive patients treated for HLHS at our institution during 1969 to 2005 were retrospectively reviewed. The number of patients with histologically confirmed HD or clinical findings characteristic of HD such as constipation and delayed meconium were recorded from the patient records.

RESULTS

A total of 113 patients (65 males) were identified. At the time of survey, 57 patients (51%) were alive. Overall, there were 26 (23%) patients with constipation, and 9/23 (39%) had delayed passage of meconium after 48 hours. Despite frequent bowel disorders only 4 (3.5%) patients had undergone histologic examination of the rectum. Hirschsprung's disease was detected in 3 patients (95% confidence interval, 0.62-8.77). The expected number of HD cases in the study population was 0.026 giving 117-fold significant increase in the incidence of HD among patients with HLHS when compared to general Finnish population.

CONCLUSIONS

The incidence of HD is increased in patients with HLHS. These results point to a common neural crest-derived embryologic origin of HD and HLHS and warrant further studies.

Histochemical staining of rectal suction biopsies as the first investigation in patients with chronic constipation

Rectal suction biopsy (RSB) is the gold standard diagnostic procedure for disorders of bowel motility. This study describes our experience with RSB stained with histochemistry as the first diagnostic approach in a large series of patients presenting with chronic constipation. Between 1993 and 2005, 766 children underwent RSB for persistent chronic constipation. The specimens were snap frozen, sectioned and stained with conventional hematoxylin and eosin (H&E) and with nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) and acetylcholinesterase (AChE) histochemical stainings. Adequate amount of submucosa was present in 655 (85.5%) out of 766 cases and formed the basis of this study. RSB in 540 (82%) patients were reported as normal. Hirschsprung's disease was found in 47 (7.2%) patients with characteristic features of absence of ganglion cells, increased AChE activity in the lamina propria and muscularis mucosae, thick nerve fibers in the submucosa, and a lack of NADPH-d-positive fibers in muscularis mucosae. RSB in 59 (9%) patients presented features of intestinal neuronal dysplasia such as submucosal hyperganglionosis, giant ganglia, ectopic ganglia and increased AChE activity in lamina propria. Hypoganglionosis was suspected in nine (1.3%) children because of sparse or absent ganglion cells and low AChE and NAPDH-d activity in muscularis mucosae. Three patients (0.4%) developed bleeding following RSB, requiring diathermy of the bleeding point. Thus, we conclude that RSB is a simple and safe method when used as the first diagnostic approach in patients with chronic constipation. The combination of two histochemical stainings techniques provides a high level of accuracy in the diagnosis of intestinal dysganglionosis.

Interstitial cells of Cajal in the normal gut and in intestinal motility disorders of childhood

Interstitial cells of Cajal (ICCs) are pacemaker cells which are densely distributed throughout the whole gastrointestinal tract. ICCs have important functions in neurotransmission, generation of slow waves and regulation of mechanical activities in the gastrointestinal tract, especially for the coordinated gastrointestinal peristalsis. Therefore, a loss of ICCs could result in gastrointestinal motor dysfunction. In recent years c-kit labeling has been widely used to study pathological changes of ICCs in gastrointestinal motility disorders. Paediatric gastrointestinal motility disorders such as hypertrophic pyloric stenosis, Hirschsprung's disease, total colonic aganglionosis, hypoganglionosis, intestinal neuronal dysplasia, internal anal sphincter achalasia, megacystis microcolon intestinal hypoperistalsis syndrome have been reported to be associated with loss or deficiency of ICCs networks. This review describes the distribution of ICCs in the normal gastrointestinal tract and its altered distribution in intestinal motility disorders of childhood.

The effect of age on colocalization of acetylcholinesterase and nicotinamide adenine dinucleotide phosphate diaphorase staining in enteric neurons in an experimental model

PURPOSE

Cholinergic and nitrergic neurons form 2 main subpopulations of the myenteric neurons, and they have been the targets of detailed morphological investigations in bowel motility disorders. However, little is known regarding the colocalization of neurotransmitters within the same enteric neurons. The aim of this study was to determine the histochemical colocalization of cholinergic and nitrergic neurons in the porcine distal large bowel myenteric plexus from fetal to adulthood.

METHODS

Distal large bowel specimens were taken from 6 randomly selected age groups (3 animals in each group) from midway of gestation to adulthood. The myenteric plexus was exposed using whole-mount technique. After nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) staining, cells per ganglion were counted. Then the specimens were stained with acetylcholinesterase (AChE), and the cells that were stained with individual enzymes and with both enzymes were counted.

RESULTS

Colocalization of AChE and NADPH-d was seen in all age groups, and it was highest during the mid part of gestation (30%) and decreased steadily thereafter into adulthood (8%). The individual number of NADPH-d- and AChE-positive neurons per ganglion remained constant till 4 weeks of age and significantly increased thereafter into adulthood.

CONCLUSION

The use of double-labeling histochemical technique shows for the first time the colocalization of cholinergic and nitrergic activity in a large population of enteric neurons in the late fetal and newborn period. Age-related loss of cholinergic and nitrergic colocalization in the myenteric plexus is most likely a maturational process.

Enteric nervous system and developmental abnormalities in childhood

ENS consists of a complex network of neurons, organised in several plexuses, which interact by means of numerous neurotransmitters. It is capable of modulating the intestinal motility, exocrine and endocrine secretions, microcirculation and immune and inflammatory responses within the gastrointestinal tract, independent of the central nervous system. Though the embryological development of various plexuses are completed by mid-way of gestation, the maturation of neurons and nerve plexuses appear to continue well after birth. Therefore, any histological or functional abnormalities related to the gastrointestinal function must be investigated with the ongoing maturational processes in mind.