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Purpose: Down syndrome (DS) is a common abnormality associated with anorectal malformation (ARM) and Hirschsprung's disease (HD). However, quality of life (QOL) in ARM and HD patients with DS is under-researched. This study compares parent-reported QOL and bowel function in ARM and HD patients with DS to those without., Methods: Between December 2020 to February 2023, parents of ARM and HD patients with and without DS aged 3-17 years who had undergone surgery > 12 months prior at four tertiary referral centers were recruited. We used the Pediatric Quality of Life Inventory™ (PedsQL™) Generic Core Scales, General Well-Being (GWB) Scale and Family Impact (FI) Module questionnaires, and the Rintala bowel function score (BFS)., Results: There were 101 ARM, 9 (8.9%) of whom had DS; and 87 HD, of whom 6 (6.9%) had DS. Parent-reported Core scores in ARM and HD with DS were comparable to those without DS. However, ARM and HD with DS had worse scores in the FI Module and bowel function than those without DS., Conclusion: Although parent-reported QOL in ARM and HD with DS is similar to those without DS, family impact and BFS are worse. Our findings are limited by small sample size in proportion of DS patients., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: The long-term impact of anorectal malformations (ARM) and Hirschsprung disease (HD) on sexual function is well recognized but understudied. This study evaluated self-reported sexual and fertility outcomes in adult males with ARM and HD., Methods: This was an IRB approved, prospective study of males in the Adult Colorectal Research Registry who completed surveys between October 2019 and March 2022. Electronic surveys were administered after consenting to being contacted for research. Patients completed the International Index of Erectile Function (IIEF) questionnaire and provided information on fertility outcomes., Results: Sixty-five patients completed outcome questionnaires: 11 (16.9%) had HD and 54 (83.1%) had an ARM. Nineteen patients reported some degree of erectile dysfunction per IIEF criteria, a greater proportion of whom have ARM (p = 0.046). Twenty (30.7%) have reported having children; there were no differences in rates between HD and ARM patients. Most patients had not attempted to conceive, but eight patients, all of whom have ARM, have pursued fertility investigation or treatments., Conclusion: More patients with ARM reported some degree of erectile dysfunction compared to those with HD. Additionally, some have required fertility treatments. Further investigation is warranted to ensure true low rates of sexual and fertility dysfunction in patients with HD., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Aim of the Study: Mowat Wilson syndrome (MWS) is a complex genetic disorder due to mutation or deletion of the ZEB2 gene (ZFHX1B), including multiple clinical features. Hirschsprung disease is associated with this syndrome with a prevalence between 43 and 57%. The aim of this study was to demonstrate the severe outcomes and the high complication rates in children with MWS, focusing on their complicated follow-up., Methods: A retrospective comparative study was conducted on patients referred to Robert-Debré Children's Hospital for MWS from 2003 to 2018. Multidisciplinary follow-up was carried out by surgeons, geneticists, gastroenterologists, and neurologists. Data regarding patient characteristics, surgical management, postoperative complications, and functional outcomes were collected., Results: Over this period of 15 years, 23 patients were diagnosed with MWS. Hirschsprung disease was associated with 10 of them (43%). Of these cases, two patients had recto-sigmoïd aganglionosis (20%), three had aganglionic segment extension to the left colic angle (30%), two to the right colic angle (20%), and three to the whole colon (30%). The median follow-up was 8.5 years (2 months-15 years). All patients had seizures and intellectual disability. Six children (60%) presented with cardiac defects. At the last follow-up, three patients still had a stoma diversion and 7 (70%) were fed orally. One patient died during the first months. Eight (80%) of these children required a second surgery due to complications. At the last follow-up, three patients reported episodes of abdominal bloating (42%), one recurrent treated constipation (14.3%), and one soiling (14.3%). Genetic analysis identified three patients with heterozygous deletions, three with codon mutations, and three with frameshift mutations., Conclusions: MWS associated with Hirschsprung disease has a high rate of immediate surgical complications but some patients may achieve bowel function comparable with non-syndromic HD patients. A multidisciplinary follow-up is required for these patients., Level of Evidence: Retrospective observational single cohort study, Level 3.

The clinical association between Trisomy 21 (Down syndrome) and aganglionosis (Hirschsprung disease; DS-HSCR) is well-established, being of the order of 5% and remains the most common congenital association with Hirschsprung disease. However, little consensus exists as to the possible etiologic and genetic factors influencing this association. Recent research has identified a number of levels at which development of the enteric nervous system is potentially affected in Trisomy 21. These include a decreased central pool of available neuroblasts for migration into the enteric nervous system, abnormal neuroblast type, poor synaptic nerve function and early germline gene-related influences on the migrating neuroblasts due to genetic mutations of a number of important developmental genes, and possible somatic mutations resulting from alterations in the local tissue microenvironment. In this paper, we review available evidence for this association. In addition, we provide evidence of both germline and somatic gene mutations suggesting causation. Although the picture is complex, recent associations between specific RET proto-oncogene variations have been shown to be significant in Down syndrome patients with Hirschsprung disease, as they probably interfere with vital RET functions in the development of the autonomic and enteric nervous systems, increasing the risk of disturbed normal function. In addition, we explore potential role of other facilitatory influence of other susceptibility genes as well as potential other chromosome 21 gene actions and the microenvironment on the Down syndrome gastro-intestinal tract. The various ways in which trisomy of chromosome influences the enteric nervous system are becoming clearer. The sum of these effects influences the outcome of surgery in Down syndrome patients with Hirschsprung Disease.

Aim: Detailed implications of age at laparoscopic transanal pull-through (LTAPT) on postoperative bowel function (POBF) in Hirschsprung's disease (HD) are somewhat obscure because of a spectrum of factors., Methods: Age at surgery was used to categorize 106 consecutive postoperative HD cases treated by our modified LTAPT (JLTPAT) between 1997 and 2015; group A: < 3 months old (n = 31); group B: 3-11 months old (n = 44); group C: 1-3 years old (n = 19); and group D: ≥ 4 years old (n = 12). POBF was assessed by reviewing outpatient records 1, 3, 5, 7, and 10 years after JLTAPT prospectively and scoring each of 5 criteria on a scale of 0-2; best score = 10., Results: Only operative time was statistically longer in group D versus groups A, B, and C. Differences in gender ratios, blood loss, duration of follow-up, and POBF scores were not statistically significant. Mean POBF scores over time were: group A: 6.8, 7.6, 8.4, 8.6, and 8.4; group B: 7.1, 7.8, 8.3, 8.5, and 9.0; group C: 6.9, 7.9, 8.1, 8.3, and 8.6; group D: 7.0, 7.4, 8.2, 8.1, and 8.5, respectively., Conclusion: Age at JLTAPT was not correlated with POBF in HD.

Aim and Objectives: Hirschsprung-associated enterocolitis (HAEC) continues to be an important cause of morbidity in patients with Hirschsprung's disease (HSCR). HAEC can occur at any time during the course of the disease. The reported incidence of HAEC before surgery ranges from 6 to 50%, and after surgery, it ranges from 2 to 35%. HAEC and inflammatory bowel disease (IBD) have similar clinical presentation including diarrhea, hematochezia, and abdominal pain. In recent years, isolated cases of IBD have been reported in patients who had surgical treatment for HSCR. The exact pathogenesis of HAEC or IBD is not known. However, both conditions are characterized by an abnormal intestinal mucosal barrier function, which may be a common pathway. The purpose of this meta-analysis was to determine the clinical presentation and outcome in patients with HSCR who developed IBD after pull-through operation., Materials and Methods: A systematic literature search for relevant articles was performed in four databases using the combinations of the following terms "inflammatory bowel disease", "Crohn/Crohn's disease", "ulcerative colitis", and "Hirschsprung disease/Hirschsprung's disease" for studies published between 1990 and 2017. The relevant cohorts of HSCR associated with IBD were systematically searched for clinical presentation and outcomes., Results: 14 studies met defined inclusion criteria, reporting a total of 66 patients who had HSCR associated with IBD. Mean age at first operation for HSCR was 5.8 months, mean age at diagnosis of IBD was 7.7 years, and the majority of patients were male (73%). The extent of aganglionosis was total colonic aganglionosis in 41% of patients, long segment in 45%, and rectosigmoid in 14%. The majority of patients underwent a Duhamel procedure (84%) for HSCR. The distribution of IBD was Crohn's disease in 72.3% of patients, ulcerative colitis in 16.9%, and others in 10.8%. Eight articles (47 patients) reported about HAEC, and 22 patients (47%) had experienced HAEC after surgery for HSCR., Conclusion: Male patients with extensive colonic aganglionosis who continue to suffer from postoperative HAEC after a Duhamel procedure are more susceptible to develop IBD. Recognition of IBD may be important in the long-term follow-up of HSCR patients who have had postoperative HAEC.

Hirschsprung disease (HSCR) is a fairly well understood congenital, genetically based functional obstruction due to the congenital absence of ganglion cells in the distal bowel. However, although over 90% of Hirschsprung cases conform to the normally accepted histological diagnostic criteria, it has become increasingly clear that in addition to HSCR, there is a group of functional disturbances relating to a number of other congenital neurodysplastic conditions causing some degree of gastrointestinal tract malfunction. Although these represent a variety of possibly separate conditions of the enteric nervous system, this spectrum it would appear to be also influenced by similar developmental processes. The term "variant Hirschsprung" is commonly used to describe these conditions, but ganglion cells are mostly present if abnormal in number and distribution. These conditions are a problem group being amongst the most difficult to diagnose and treat with possible practical and legal consequences. The problem appears to be possibly one of definition which has proven difficult in the relative paucity of normal values, especially when correlated to age and gestation. It is the purpose of this paper to review the current position on these conditions and to explore possible shared common pathogenetic and genetic mechanisms. This article explores those conditions where a similar pathogenetic mechanisms to HSCR can be demonstrated (e.g. hypoganglionosis) as well as other neural features, which appear to represent separate conditions possibly linked to certain syndromes.

Background/aim: The behavior of enteric neural crest-derived cells (ENCC) during enteric nervous system (ENS) development is being gradually understood with the introduction of live-cell imaging. However, many of the analyses to date are two-dimensional and the precise multidirectional migration of ENCC has been challenging to interpret. Mice lacking the endothelin-B receptor gene, Ednrb (-/-) mice, are widely used as a model for Hirschsprung's disease (HD). We have recently developed a Sox10 transgenic (Tg) mouse to visualize ENCC with enhanced green fluorescent protein (Venus). By breeding these two models, we have created a Venus-positive, Sox10 Tg mouse with a deletion of the Ednrb gene, Sox10-Venus(+)/Ednrb (-/-) mouse, to investigate the ENS in HD. The aim of this study was to investigate the behavior of migrating ENCC in the hindgut of the Sox10-Venus(+)/Ednrb (-/-) mouse using three-dimensional and four-dimensional image analysis software., Methods: To compare the ENCC behavior when the wavefront of ENCC reaches the mid-hindgut between HD mouse and control, we harvested the fetal hindguts of Sox10-Venus(+)/Ednrb (-/-) mice on embryonic day 15.5 (E15.5) and Sox10-Venus(+)/Ednrb (+/+) mice on E12.5, which was used as control. Dissected hindguts were cultured for 360 min and the time-lapse images were obtained using a confocal laser-scanning microscope. Each ENCC at the wavefront was tracked after adjusting the longitudinal axis of the gut to the Y axis and analyzed using Imaris software., Results: Track displacement (TD)-Y indicates ENCC advancement in a rostral-caudal direction. TD-X and TD-Z indicate ENCC advancement perpendicular to the rostral-caudal axis. Mean TD-Y was 34.56 µm in HD, but 63.48 µm in controls. TD-Y/TD-XZ was not significantly different in both groups. However, the mean track speeds were significantly decreased in HD (72.87 µm/h) compared to controls (248.29 µm/h)., Conclusions: Our results showed that the track speed of ENCC advancement was markedly decreased in the HD mice compared to controls. This technique provides added information by tracking ENCC with depth perception, which has potential for further elucidating the altered behavior of ENCC in HD.

Purpose: The pathophysiology of Hirschsprung's disease (HSCR) is not entirely understood. There is no clear explanation for the occurrence of the spastic or tonically contracted aganglionic segment of bowel. Kv11.1 (hERG) channels play a critical role in the regulation of the resting membrane potential as well as affecting either the force or frequency of contraction of smooth muscles. We designed this study to investigate the expression and distribution of hERG channels in the normal colon and the colon of patients with HSCR., Methods: We investigated hERG protein expression in both the ganglionic and aganglionic regions of HSCR patients (n = 10) versus normal control colon (n = 10). Protein distribution was assessed using immunofluorescence and confocal microscopy. Gene and protein expressions were quantified using real-time polymerase chain reaction, western blot analysis and densitometry., Results: Confocal microscopy of the normal colon revealed strong hERG channel expression in interstitial cells of Cajal, platelet-derived growth factor-alpha receptor- (PDGFRα(+)) positive cells and enteric neurons. hERG expression was markedly decreased in aganglionic bowel, whereas colonic hERG gene expression levels were significantly decreased in aganglionic compared to ganglionic bowel and controls (p < 0.05). Western blotting revealed decreased colonic hERG protein expression in aganglionic HSCR specimens compared to controls., Conclusions: We demonstrate, for the first time, the expression and distribution of hERG channels in the human colon. The decreased expression of hERG in the aganglionic colon may be responsible for the increased tone in the aganglionic narrow spastic segment of bowel.

Total colonic aganglionosis is a relatively uncommon form of Hirschsprung's disease (HSCR). It occurs in approximately 2-13 % of HSCR cases and involves the entire colon which is aganglionic but may extend proximally into varying lengths of small bowel. As a result, it should be separated into Total colonic aganglionosis (TCA) [defined as aganglionosis extending from the anus to at least the ileocaecal valve but no more than 50 cm small bowel proximal to the ileocaecal valve] and total colonic and small bowel aganglionosis (TCSA) which may involve very long segments of small bowel aganglionosis. Clinically, TCA appears to represent a different spectrum of disease in terms of presentation and difficulties which may be experienced in diagnosis suggesting a different pathophysiology from the more common forms of HSCR. It is therefore not yet clear whether TCA merely represents a long form of HSCR or a different expression of the disease. A number of differences exist between TCA and other forms of HSCR which require explanation if its ubiquitous clinical features are to be understood. In addition to the usual explanations for the aganglionosis of HSCR, there is some evidence suggesting that in place of being purely congenital, it may represent certain different pathophysiologic mechanisms, some of which may continue to be active after birth. This study reviews what is known about the clinical, radiological and histopathologic differences between TCA and the more frequently encountered recto-sigmoid (or short-segment; S-HSCR) and correlates them with what is currently known about the genetic and molecular biologic background to find possible pathogenetic mechanisms.

Hirschsprung disease (HD) is the most prevalent congenital gastrointestinal motility disorder. The pathogenesis of HD is defined as a functional intestinal obstruction resulting from a defect in the intrinsic innervation of the distal bowel. In addition to the enteric nervous system, the interstitial cells of Cajal (ICC) play an important role in the generation of coordinated gastrointestinal peristalsis. The major function of the ICCs is the generation of slow waves that allow these cells to act as specialised pacemaker cells within various tissues. ICCs have additional functions in the gastrointestinal tract as regulators of mechanical activity and neurotransmission. Due to the central role of ICCs in gastrointestinal peristalsis, it has been suggested that defects or impairments of the ICCs may contribute to motility dysfunction in several gastrointestinal motility disorders. This review describes the distribution and functions of ICCs in the normal gut and in Hirschsprung disease.

Introduction: There is accumulating evidence that "skip" lesions or zonal aganglionosis do occur in HSCR disease, albeit rarely. They are of interest because it may cause confusion in interpreting surgical margins as well as understanding the pathophysiology of HSCR disease. Normally described as "a skip area" of normally ganglionated bowel, surrounded proximally and distally by aganglionosis with variations may occur., Case Reports: We report two cases of infants with unusual types of "skip lesions", identified within the last 5 years., Results: One patient had an area of zonal aganglionosis in the transverse colon and recto-sigmoid, bordered by areas of normally enervated bowel in the right and descending colon. In the second patient, the terminal ileum, transverse, descending and sigmoid colons and rectum were histologically aganglionic, but focal patches of ganglion cells were identified in 21 cm of the right ascending colon and the appendix, suggesting some ENS plasticity and possible incomplete apoptosis., Conclusion: These cases illustrate the point that the presence of ganglion cells at the resection line is not sufficient to guarantee postoperative function and "skip" lesions may uncommonly confuse the picture. In addition, they raise questions as to its pathophysiology and favor an alternate hypothesis of local changes promoting neuroblast apoptosis as the possible cause.

Background: Hirschsprung's disease (HD) presenting late is not unusual in developing nations., Aim: To study surgical procedures and postoperative outcome in Hirschsprung's disease (HD) presenting after infancy., Method: Records of 112 cases of confirmed HD who presented after infancy were analyzed for clinical presentations, investigations, surgical procedures and postoperative outcome. A Boley Scot pull through procedure was performed in all with or without a preliminary transverse colostomy., Results: The ages varied from 1 to 35 years. The rectosigmoid region was involved in all. Five cases presented with enterocolitis. Open biopsy and a diverting colostomy was performed in 91 cases (82%) with a colotomy in 4 for removal of fecalomas due to bowel dilatation on Barium study. This was followed by Boley Scot abdominal perineal pull through in 80 and Classical Soave in 11. Only 21 cases (18%) underwent single-stage endorectal pull through. Postoperative complications were encountered in 11/112 (9.8%)., Conclusion: 82% children with HD presenting late required staged procedures due to dilated bowel. Single-stage pull through was feasible only in 18% cases. The postoperative complications were uncommon and managed successfully.

Purpose: The enteric nervous system (ENS) is a network of neurons and glia that lies within the gut wall. It is responsible for the normal regulation of gut motility and secretory activities. Hirschsprung's disease (HD) is a congenital defect of the ENS, characterised by an absence of ganglia in the distal colon. Intestinal neuronal dysplasia (IND) is a condition that clinically resembles HD, characterised by hyperganglionosis, giant and ectopic ganglia, resulting in intestinal dysmotility. Intestinal ganglioneuromatosis is characterised by hyperplasia and hypertrophy of enteric neuronal cells and causes chronic intestinal pseudo-obstruction (CIPO). Phosphatase and tensin homolog deleted on chromosome 10 (Pten) is a phosphatase that is critical for controlling cell growth, proliferation and cell death. A recent study of Pten knockout mice showed evidence of ganglioneuromatosis in the ENS suggesting a role for this protein in ENS development. Ganglioneuromatosis patients have also been shown to have a decreased level of Pten expression in the colon. The aim of our study was to investigate Pten expression in the ENS of HD and IND patients compared to normal controls., Methods: Resected tissue from 10 HD and 10 IND type B patients was fixed and embedded in paraffin wax. Normal control colon tissue was obtained from ten patients who underwent a colostomy closure for imperforate anus. Sections were cut and immunohistochemistry was carried out using a Pten antibody. Results were analysed by light microscopy., Results: Staining showed that Pten was strongly expressed in ganglia of both the submucosal and myenteric plexus of normal and HD specimens from the ganglionic colon. Pten expression was significantly reduced in the giant ganglia in IND patients in both the myenteric and submucosal plexuses compared to the normal controls. Specimens from the aganglionic region of HD did not show Pten expression., Conclusion: To the best of our knowledge, this is the first study demonstrating a marked reduction of Pten expression in the myenteric and submucous plexuses of IND patients. Neuronal Pten deficiency in IND may disrupt the chemical pathway associated with the proliferation and development of neuronal cells forming mature ganglia and thus cause motility dysfunction.

Purpose: The definitive surgical management of Hirschsprung's disease (HD) depends on an unambiguous histological diagnosis of bowel aganglionosis, as well as an accurate assessment of its proximal extent from the rectum or 'leveling'. This study aimed to evaluate and compare the transition zone in rectosigmoid and long segment colonic forms of HD., Methods: One hundred and fifteen cases of rectosigmoid Hirschsprung's disease (RSHD) and 20 cases of long segment colonic Hirschsprung's disease (LScHD) managed from 1998 to 2008 with a consensus prospective protocol were included in this clinicopathological analysis., Results: In RSHD, the radiologic transition zone (rTZ)/gross appearance at laparotomy correlated with the histological 'leveling' in the majority (96%); the histologic transition zone was also short and predictable. In contrast, the rTZ in LScHD was conclusive in only 53%; overall the radiologic and histological transition zones concurred in only 26%. The histologic transition zone extended proximally for an unpredictable length before normal circumferential innervation was noted., Conclusions: A stringent intraoperative histological evaluation of the colon as outlined is more helpful than radiology to establish the distal level of normally innervated bowel in LScHD and achieve an accurate leveling during a colostomy/pull through.

Purpose: Lack of ganglion cells is the main cause of bowel movement disorder in Hirschsprung's disease. Because smooth muscle is the primary organ, the properties of intestinal smooth muscle need to be investigated. We therefore investigated the reactivity of the contractile system and the mechanism of contraction in aganglionic intestinal smooth muscle., Methods: Colonic smooth muscle strips from endothelin-B receptor gene-deficient [EDNRB(-/-)] rats were loaded with the Ca(2+) indicator dye fura-PE3/AM and changes in fluorescence intensity were monitored. The intracellular calcium concentration ([Ca(2+)]i) and force development in the strips were measured simultaneously., Results: The force induced by 10 microM substance P (SP) was higher than that induced by 60 mM K(+) depolarization (control), whereas [Ca(2+)]i elevation induced by 10 microM SP was less than that induced by 60 mM K(+) in all segments. Pretreatment with the Rho-kinase inhibitor Y-27632 inhibited force development more strongly in EDNRB(-/-) aganglionic segments than in EDNRB(+/+) ganglionic segments. However, [Ca(2+)]i was higher in EDNRB(-/-) aganglionic segments than in EDNRB(+/+) ganglionic segments., Conclusions: The Ca(2+)-independent pathway involving Rho-kinase was hyperactivated in EDNRB(-/-) aganglionic segments. This phenomenon is assumed to compensate for Ca(2+) channel downregulation and Ca(2+)-dependent contraction. From a clinical point of view, the motility of aganglionic intestine would be controllable with the control of Ca(2+)-independent contraction before definitive operations in Hirschsprung's disease.

Introduction: The enteric nervous system is an intrinsic network of nerve cells and glia within the gastrointestinal wall, which originates in the vagal and sacral neural tube. The vagal neural tube is known to supply the colorectum with the majority of its nerve cells, and its ablation during early development produces a hypoganglionic colorectum. We hypothesized that the cholinergic nerve activity in the chick embryo hypoganglionic colorectum is decreased similar to the human situation and, therefore, this study is designed to investigate cholinergic innervations in the chick embryo hypoganglionic colorectum., Materials and Methods: Chicken eggs were incubated until embryos reached the 10-12 somite stage. The vagal neural tube was microsurgically ablated and eggs were returned to the incubator until embryos reached E12 and E14. Whole embryos were fixed and embedded in paraffin wax. Transverse sections were cut and immunohistochemistry was performed using a neural crest cell antibody, human natural killer-1 (HNK-1), and a choline acetyltransferase antibody (ChAT)., Results: The results showed that in normal embryos, the colorectum contained many nerve cells (HNK-1) and ChAT-positive nerve cells and fibres, while in embryos with a hypoganglionic colorectum, the number of nerve cells (HNK-1) and ChAT-positive nerve cells and fibres was decreased., Conclusion: Cholinergic nerve activity is decreased as a result of a reduction in nerve cell numbers in the chick embryo colorectum. These results suggest that the cholinergic activity in the hypoganglionic chick model resembles that of human hypoganglionosis.

Total colonic aganglionosis is a relatively uncommon form of Hirschsprung's disease (HSCR) occurring in approximately 2-13% of cases. It can probably be divided into total colonic aganglionosis (TCA; defined as aganglionosis extending from the anus to at least the ileocaecal valve, but no more than 50 cm proximal to the ileocaecal valve) and total colonic and small bowel aganglionosis, which may involve a very long segment of aganglionosis. Clinically, they appear to represent a different spectrum of disease in terms of presentation and difficulties in diagnosis which may be experienced, suggesting a different pathophysiology from the more common forms of HSCR. It is not yet clear whether TCA merely represents a long form of HSCR or a different expression of the disease. There are a number of differences between TCA and other forms of HSCR, which require an explanation if its ubiquitous clinical features are to be understood. There is some evidence suggesting that instead of being purely congenital, it may represent certain different pathophysiologic mechanisms, some of which may continue to be active after birth. This study reviews all that is known about the clinical, radiological and histopathologic differences between TCA and the more frequently encountered recto-sigmoid (or short-segment) and correlates them with what is currently known about the genetic and molecular biologic background to find possible pathogenetic mechanisms.

The transanal endorectal pull-through (TAEPT) procedure is now widely performed for Hirschsprung's disease (HD), however, the colorectal function after TAEPT has not yet been adequately assessed. We evaluated the postoperative clinical outcome and colorectal function based on lower colonic manometry after TAEPT. Twenty-one cases of HD underwent TAEPT from 1998 to 2005. We examined the clinical outcome based on the requirement of enemas/suppositories, the number of defecations per day, the severity of perianal erosion, and the incidence of enterocolitis requiring hospital stay. Using a three-channel Dentsleeve catheter and UPS-2020 measuring device, we performed postoperative colonic manometry at three locations: (1) the anal canal, (2) 5 cm proximal to the anal canal, and (3) 10 cm proximal to the anal canal, during defecation, and then we measured the appearance of high-amplitude contraction (HAC) (duration >/=10 s, amplitude >/=100 cmH(2)O). Four of 21 cases were treated with enemas/suppositories no longer than 1 year. The number of defecations decreased gradually from 4 to 5 per day in the early postoperative period, reaching 2 to 3 per day about 1 year postoperatively. Perianal erosion was noted in 3 of 21 cases but it disappeared within three postoperative years. Two cases had enterocolitis. Lower colon manometry was performed in eight cases. Manometry during defecation was successfully monitored in six cases. HAC occurred in five of six cases (83.3%). The clinical outcomes after TAEPT were satisfactory in almost all cases. These good outcomes were possibly due to the occurrence of HAC during defecation, though HAC did not fill the definition of high amplitude propagated contractions (HAPCs). The occurrence of HAC after TAEPT might be caused by keeping any damage to the mesenteric ascending cholinergic nerve to a minimum during surgery. Further long-term observations are still required to make an adequate assessment of such cases.

We examined the interaction between the sacral neural system and the anorectal activity using a technique comprising repetitive magnetic stimulation. Thirteen control children without any bowel dysmotility (age range; 3 month old to 15 year old), 20 patients with chronic constipation (1 month old to 14 year old), and nine pre-operative patients with Hirschsprung's disease (1 month old to 6 year old) were examined. Magnetic stimulation was applied at the S3 level using the MagPro (Medtronic) device while simultaneously performing manometric recordings of the anorectal activity. In the 13 controls and the 20 patients with chronic constipation, the rectoanal reflex was demonstrated by balloon rectal dilatation. The sphincter response to magnetic stimulation was biphasic in the controls, consisting of an initial rise followed by a decrease in the sphincter pressure, while it varied among the patients with chronic constipation including a biphasic response in 16 patients, no response in three patients, and only a transient rise in pressure in one patient. In nine pre-operative patients with Hirschsprung's disease, no rectoanal reflex was observed, however, the sphincter pressure increased due to magnetic stimulation in six patients, while three patients exhibited no recordable responses. These results suggest that the repetitive magnetic stimulation technique is a valuable modality for investigating the neural interaction between the sacral nervous system and the anorectum.

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.

Although various surgical procedures have been described to treat Hirschsprung's disease (HD), few studies have evaluated the long-term results of these children. The purpose of this study was to assess the long-term clinical outcome and bowel function of patients with HD. The hospital records of 259 consecutive patients with a confirmed histological diagnosis of HD during 1975-2003 were examined. Data was assessed for age at presentation, sex, clinical presentation, associated anomalies, level of aganglionosis, surgical procedures, complications and bowel function. Follow up was carried out by personal/telephone interviews with patients or their parents. Of the 259 patients with HD, 200 were males (77.2%) and 59 females (22.8%). Intestinal obstruction was the presenting feature in 147 patients (56.8%), intestinal perforation in 5 (1.9%), enterocolitis in 30 (11.6%) and constipation in 77 (29.7%). Thirty-nine patients (15.1%) had associated Down's syndrome. Two hundred and nine patients (80.7%) had rectosigmoid disease, 31 (12%) had long segment disease and 19 (7.3%) had total colonic aganglionosis. Forty-three patients (16.6%) had preoperative enterocolitis. Primary colostomy was performed in 160 patients and a primary pull through in 90. Seven patients had a sphincteromyectomy for ultrashort HD. Two patients died prior to treatment. Various pull through procedures were performed in these patients. Postoperative complications included: pelvic abcess in 2, rectal stricture in 10, perianal excoriation in 7, anastomotic leak in 8, intestinal obstruction in 3, wound dehiscence in 1, stomal prolapse/stenosis in 5, rectovesical fistula in 2 and enterocolitis in 56. Five patients underwent a redo pull through and 46 required a post pull through sphincterectomy. At the time of follow-up, 27 were lost to follow-up, 9 died, 18 had permanent stomas and 4 were too young to assess bowel function. Of the remaining 194 patients, bowel function was normal in 132 (68%). Twenty patients (10.3%) had soiling and 42 (21.7%) had constipation requiring laxatives or enemas. There was no difference in bowel function in relation to type of pull through operation. Only 34% of patients with Down's syndrome had normal continence. The majority of patients with HD continue to have disturbances of bowel function for many years before attaining normal continence.

The management of Hirschsprung's disease (HD) has made dramatic strides over the last 20 years. Research into the embryological development and migration of ganglion cell has enabled a greater understanding of the pathogenesis of the disease. Coupled with new techniques in surgery, such as laparoscopy-assisted pull-through and the transanal pull-through, this knowledge has led to improved outcomes for children with HD. However, although our appreciation of Hirschsprung's associated enterocolitis and its aetiology has increased, there are continued references in the literature to a multitude of theories of pathogenesis. The purpose of this review is to delineate the theories and demonstrate the evidence supporting or otherwise contradicting each other.

The association between the congenital absence of colonic ganglion cells and an increased acetylcholinesterase (AChE) expression in the affected tissue is of diagnostic importance in Hirschsprung's disease (HSCR). Investigation of AChE's function in development may also help unravel some of the complex pathophysiology in HSCR. Normal nerves do not stain for AChE, but increased AChE expression is associated with the hypertrophied extrinsic nerve fibres of the aganglionic segment in HSCR. Although a high degree of histochemical diagnostic accuracy exists, results are not always uniform, and false positives and false negatives are reported. False negative results are primarily related to age, and an absence of AChE reaction does not exclude HSCR in neonates within the first 3 weeks after birth. AChE staining results may lack uniformity, resulting in a number of technical modifications that have been made to improve standardization of AChE staining. At least two distinct histological patterns are described, types A and B. The interpretation of increased AChE staining patterns in ganglionated bowel at the time of surgical pull-through remains a problem in patients with HSCR. The development of rapid staining techniques has helped to identify normal ganglionated bowel with greater certainty. The presence of fine AChE neurofibrils in the ganglionated segment has contributed to the debate surrounding intestinal neuronal dysplasia. Quantitative assay of cholinesterase activity confirms the pattern of histochemical staining. AChE is particularly increased in relation to butrylcholinesterase, with one molecular form, the G4 tetrameric form, predominating. It is likely that the raised levels of AChE in aganglionic tissue are the transcriptional consequence of the abnormalities in signalling molecules that characterize HSCR. Evidence suggests that this AChE is functioning in a nonenzymatic capacity to promote cell adhesion and differentiation and that the hypertrophied nerves and neurofibrils may be the result of this increased AChE expression.

Intestinal neuronal dysplasia is a controversial form of dysganglionosis that has been described both as an isolated disorder and in association with Hirschsprung's disease. It has been blamed for the bad outcome of bowel function in patients operated on for Hirschsprung's disease. According to various authors, intestinal neuronal dysplasia could be a primary disorder or secondary to other diseases of the bowel. The aim of this study was to assess the plasticity of the enteric nervous system in patients with Hirschsprung's disease-associated intestinal neuronal dysplasia and its ability to evolve spontaneously to normal innervation patterns. Since we prospectively introduced the assessment of the enteric nervous system of the ganglionated bowel in patients operated on for Hirschsprung's disease, 31 patients have been operated on for Hirschsprung's disease in our institution between 1995 and 2002. Among these patients, nine suffered postoperatively from severe constipation and five from bouts of entocolitis. IND was found in eight of them. We studied the evolution of the innervation in three of these patients by repeated serial full-thickness biopsies of the colon. All three patients underwent a colostomy before or after the pull-through procedure. Histopathological assessment of the enteric nervous system was made with conventional acetylcholinesterase histochemistry, rapid acetylcholinesterase histochemistry and immunohistochemistry for the Protein Gene Product 9.5 and the antigen CD56. This evolution was compared with the clinical outcome of bowel function. In our three patients with Hirschsprung's disease-associated intestinal neuronal dysplasia, this form of dysganglionosis evolved to normal innervation patterns within a period ranging from 9 to 18 months. This evolution was accompanied by an improvement of bowel function in all. We conclude that Hirschsprung's disease-associated intestinal neuronal dysplasia can evolve to a normal innervation, at least under certain circumstances such as a colostomy. Specific histopathological techniques are required to assess accurately the enteric nervous system.

Surgery for Hirschsprung's disease is often complicated by post-operative bowel motility disorders. The impact of intestinal neural histology on the surgical outcome has been previously studied, but no information is available concerning the influence of the distribution of interstitial cells of Cajal (ICC) on these complications. These cells are considered to be pacemakers in the gastrointestinal tract. The aim of this study was to assess the distribution of ICC in the proximal segment of resected bowel in Hirschsprung's disease and confront these results with the clinical outcome. Using immunohistochemistry for light microscopy, we compared the pattern of distribution of ICC in the proximal segment of resected bowel in Hirschsprung's disease with that in normal colon. We correlated these results with the corresponding neural intestinal histology determined by CD56 and the protein gene product 9.5 immunohistochemistry. The distribution of ICC in the proximal segment of resected bowel is identical to that of normal colon, regardless of normal or abnormal colon innervation. ICC distribution does not seem to contribute to post-operative bowel motility disorders in patients operated for Hirschsprung's disease

Total colonic aganglionosis (TCA) is a severe form of ultra long Hirschsprung's disease with an incidence of 2 to 14% among all forms of intestinal aganglionosis. C-kit positive interstitial cells of Cajal (ICCs) are pacemaker cells that play a key role in the motility function of the bowel. The aim of this study was to compare the innervation and ICCs distribution in total colonic and recto-sigmoid HD. Full thickness colonic specimens were obtained from four children with TCA, ten with recto-sigmoid HD and four controls. Single immunohistochemistry using peripherin, neuronal nitric oxide synthase (nNOS) and c-kit antibody was performed and analysed in light microscopy. Additionally, whole-mount preparations were stained using anti c-kit immunohistochemistry and NADPH-diaphorase. In the ganglionic bowel of TCA, recto-sigmoid HD and control patients there was a strong nNOS and peripherin immunoreactivity (IR) in ganglia of myenteric and submucous plexus and in thin nerve fibres in the muscle layers. In the TCA there was weak or lack of nNOS IR in the sparse, short nerve trunks of the myenteric and submucous plexuses and muscle layers, whereas nNOS weakly positive nerve trunks were observed in the recto-sigmoid HD bowel. Peripherin IR was markedly reduced in the TCA specimens compared to recto-sigmoid HD. In the TCA specimens there was a lack of ICCs-MY in the smooth muscle layer in all the specimens, whereas in the recto-sigmoid aganglionic bowel ICCs-MY were markedly reduced. Whole-mount preparations showed lack of ICCs-MY and a markedly reduced number of NADPH-positive nerve trunks in TCA. Our findings demonstrate clear histopathological differences between rectosigmoid Hirschsprung's disease and total colonic aganglionosis.

Surgery for Hirschsprung's disease is associated with high rate of morbidity, in the form of either constipation or incontinence or a combination of the two. This study investigates the mechanisms responsible for incontinence and/or constipation following the pull-through operation for Hirschsprung's disease. There were 19 children (15 boys and 4 girls), who at the time of study; 16 had undergone Duhamel, 1 Rehbein, and 2 Soave operation. We classified patients according to their symptoms into 3 groups: Group A was incontinent of faeces; Group B was constipated and incontinent of faeces, and Group C was constipated only. The median age at referral was 6 years, and the median period after operation was 5 years. All patients were investigated by intestinal transit study, endoanal sonography and anorectal manometry. Group A had normal or rapid transit study, as opposed to Groups B and C, who had delayed-transit study. On endoanal sonography, all children had an intact internal and an external anal sphincter, below the level of pull-through operation. The anorectal manometry showed a significantly lower resting anal pressure in the incontinent Group A as compared to the constipated children with or without incontinence in Group B or C (38 mmHg versus 57 or 66 mmHg respectively). The rectal pressure was also significantly higher in children in Group A as compared to those in Group B or C (71 mmHg versus 42 or 36 mmHg). The ratio of rectal/anal pressure was higher in incontinent children in Group A, as compared to constipated children in Group B or C. Therefore, constipation can be caused by high anal resting pressure and a weak rectal peristalsis, while faecal incontinence can be secondary to poor compliance and elevated rectal pressure in the presence of normal or low anal sphincter resting pressure. Aperients are the mainstay of treatment of constipation, however, children with incontinence are more difficult to treat. We did not attempt to define the pattern of nerve plexus because of poor results of revision operation for residual hypoganglionic segment and intestinal neuronal dysplasia. Treatment of these children can become more rational, if furnished with detailed functional studies. We advocate investigation of the anorectal function at an early stage in symptomatic children after surgery for Hirschsprung's disease, and less invasive treatment should be considered before embarking on major surgery.

Vasoactive intestinal peptide (VIP) is the most important peptidergic transmitter in intestinal relaxation. VIPergic nerves are reduced in aganglionosis (AG). Corresponding findings in intestinal neuronal dysplasia (IND) are sparse. It is unknown whether superficial mucosal VIP receptors are reduced in AG, IND, or hypoganglionosis (HYP) compared to concentrations in morphologically normal innervated colon (MNIC). Cryostat sections from 38 colonic biopsies (23 patients with AG, IND, or HYP, 15 with MNIC) were incubated with radioactive iodinated (125)I-VIP. Receptors were analyzed by autoradiography. Radioactive-marked receptors trigger the precipitation of metallic silver as silver grains within a photographic emulsion. Grains were quantified by image analysis, calculating the percent covered cell surface. Statistical analysis was done by Mann-Whitney and Kruskal-Wallis tests (significance #E5/E5#<0.05). VIP receptors covered 4.31% of the cell surface in MNIC. The values were significantly reduced in AG (2.72%; #E5/E5#=0.012) and IND (2.93%; #E5/E5#=0.008). The two HYP biopsies showed the lowest values (1.83%). Aganglionic colon could be distinguished from healthy proximal segments and IND from habitual constipation. In AG and IND, even the superficial mucosal VIPergic innervation seems to be impaired. The reduction of mucosal VIP receptors in developmental faults of the enteric nervous system may thus be an indicator of a sensomotor disturbance.

Hirschsprung's disease (HD) is characterised by the absence of ganglion cells and the presence of hypertrophic nerve trunks in the distal bowel. It has been suggested that aganglionosis may be caused by failure of differentiation as a result of microenvironmental change after neuronal migration has occurred. Recently, it was reported that cell-adhesion molecules (CAMs) and fibroblast growth factors (FGFs) stimulate neurite outgrowth through activation of FGF receptors (FGFRs) in neurons. The aim of this study was to investigate the expression of CAMs FGFs, and FGFRs in ganglionic (NG) and aganglionic (AG) segments of HD in order to understand the role of CAM-FGF signalling in the pathogenesis of HD. Specimens from NG and AG segments of bowel from 11 patients with HD were obtained at the time of definitive pull-through operation, snap-frozen in OCT compound, and stored at -70 degrees C. Aganglionosis was confirmed by Haematoxylin and eosin staining and acetylcholinesterase histochemistry; 8-micron cryosections were immunostained using the standard streptavidinbiotin-immunoperoxidase method. The following antibodies were used as the first antibody; FGF2 and FGF7 for FGFs, FGFR1 and FGFR2 for FGFRs, NCAM, L1CAM, and N-cadherin for CAMs. FGF2, FGF7, and FGFR2 were expressed in neuronal tissue of NG segments as well as in hypertrophic nerves of AG segments. There was a lack of FGFRI expression in neuronal tissue of both NG and AG bowel. Immunoreactivity with all three CAMs was detected in ganglion cells in NG bowel and in hypertrophic nerve trunks in AG bowel. In contrast the numbers of CAM-positive nerve fibres in muscle layers were markedly decreased in AG bowel compared to NG bowel. The markedly decreased expression of CAMs on nerve fibres within the muscle of AG bowel suggests that CAM-FGF signalling is altered in HD, resulting in failure of enteric neuroblast migration.

Internal anal sphincter achalasia (IASA) is a condition with a clinical presentation similar to Hirschsprung's disease, but with the presence of ganglion cells on rectal biopsy. The diagnosis of IASA is made on anorectal manometry, which demonstrates the absence of a rectosphincteric reflux on rectal balloon inflation. In order to understand the nature of neuronal abnormalities in this condition, we performed immunohistochemistry using PGP 9.5 (a general neuronal marker) and synapsin I (a presynaptic marker) in IAS specimens from 10 patients with IASA and 8 normal controls. In the IAS of normal controls, there were many PGP 9.5 and synapsin I-positive nerve fibers. In IASA PGP 9.5-immunoreactive fibers were markedly reduced and synapsin I-positive fibers were either absent or markedly reduced. Our findings demonstrate that the IAS in achalasia patients has defective intramuscular innervation as well as defective innervation of the neuromuscular junction, thereby contributing to the motility dysfunction.

Long-term functional results, anal endosonography (AES), and anal canal manometry were recorded in 48 patients aged 10 to 24 years (median 18) operated upon with the Duhamel technique for Hirschsprung's disease; 60.4% had perfect fecal control, 31.3% occasional staining and/or gas incontinence, and 8.3% constant fecal soiling, and 10.4% complained of constipation. Compared to normals, the patients had significantly reduced anal canal resting and squeeze pressures. AES visualized scar tissue in both the internal and external anal sphincter.