Hirschsprung's disease

Hirschsprung's disease (HSCR) is characterized by absence of the enteric nervous system in a variable portion of the distal gut. Affected infants usually present in the days after birth with bowel obstruction. Despite surgical advances, long-term outcomes remain variable. In the last 2 decades, great advances have been made in understanding the genes and molecular biological mechanisms that underlie the disease. In addition, our understanding of normal enteric nervous system development and how motility develops in the developing fetus and infant has also increased. This review aims to draw these strands together to explain the developmental and biological basis of HSCR, and how this knowledge may be used in the future to aid children with HSCR.

After the honeymoon comes divorce: long-term use of the antegrade continence enema procedure

BACKGROUND

Having reported that 18% of children discontinue use of the antegrade continence enema (ACE) after 5 years, we aimed to determine long-term use after an ACE procedure.

METHODS

A postal/telephone questionnaire was conducted. Subjects were consecutive children undergoing an ACE between 1993 and 1999. Outcome measures were use of ACE, reasons for nonuse, complications, and overall satisfaction.

RESULTS

Of 84 eligible subjects, data were available on 61 (73%) aged 22.4 years (15.5-35.1 years). Underlying diagnoses included spina bifida (n = 27), anorectal malformations (n = 18), constipation (n = 11), Hirschsprung's disease (n = 1), sacral agenesis (n = 2), and trauma/tumor (n = 2). Follow-up was 11.02 years (8.34-14.39 years). Thirty-six (59%) of 61 patients were still using their ACE. Reasons for nonuse were lack of effectiveness (n = 14), complications (n = 5), psychologic issues (n = 2), and poor compliance (n = 2). There was no association between diagnosis and nonuse (chi(2), P = .63). In those still using ACE, the overall satisfaction score was 4.1 (1-5). Several individuals reported feeling abandoned on becoming adults and losing the support they had in childhood.

CONCLUSION

There is a late "failure" rate for the ACE procedure. However, satisfaction was high among those still using the ACE. This study further emphasizes the need for robust transitional care arrangements.

Properties of secondary and tertiary human enteric nervous system neurospheres

Advances in enteric nervous system (ENS) stem cell biology have raised the possibility of treating Hirschsprung's disease with ENS stem/progenitor cell (ENSPC) transplantation. This study aimed to expand ENSPC numbers by the growth and redissociation of neurospheres and assess their differential potential.

METHODS

Human ENS neurospheres were cultured as previously described and redissociated to generate secondary and tertiary neurospheres. Neurospheres were assessed for the presence of neuronal (PGP9.5), glial (S100), and stem cell (p75, nestin markers). The degree of immunofluorescence was quantified using the ImageJ program. Secondary/tertiary neurospheres were transplanted into mouse distal colon grown in tissue culture.

RESULTS

Secondary/tertiary neurospheres could be generated with exponentially increasing numbers. Tertiary neurospheres showed a significant increase in the proportion of p75 staining but a significant decrease in the proportion of S100 staining. After transplantation, secondary/tertiary neurosphere-derived cells positive for PGP9.5 and S100 could be identified.

CONCLUSIONS

It is possible to exponentially expand neurosphere and therefore ENSPC numbers by repeated dissociation and culture. There is a loss of S100-positive cells in secondary/tertiary neurospheres, but the ENSPCs remain capable of differentiating into neurons and glia when transplanted into an embryonic gut environment.

Negative exploration for pyloric stenosis--is it preventable?

BACKGROUND

The diagnosis of infantile hypertrophic pyloric stenosis (IHPS), although traditionally clinical, is now increasingly dependent on radiological corroboration. The rate of negative exploration in IHPS has been reported as 4%. The purpose of our study was to look at elements of supportive clinical evidence leading to positive diagnosis, and to review these with respect to misdiagnosed cases undergoing negative exploration.

METHODS

All infants undergoing surgical exploration for IHPS between January 2000 and December 2004 were retrospectively analysed with regard to clinical symptoms, examination findings, investigations and operative findings.

RESULTS

During the study period, 343 explorations were performed with a presumptive diagnosis of IHPS. Of these, 205 infants (60%) had a positive test feed, 269 (78%) had a positive ultrasound scan and 175 (55%) were alkalotic (pH >or=7.45 and/or base excess >or=2.5). The positive predictive value for an ultrasound (US) diagnosis was 99.1% for canal length >or=14 mm, and 98.7% for muscle thickness >or=4 mm. Four infants (1.1%) underwent a negative surgical exploration; Ultrasound was positive in 3, and negative in 1(who underwent surgery on the basis of a positive upper GI contrast). One US reported as positive had a muscle thickness <4 mm. Two false positive US were performed at peripheral hospitals. One infant had a false positive test feed following a positive ultrasound diagnosis. Two infants had negative test feeds.

CONCLUSION

A 1% rate of negative exploration in IHPS compares favourably with other studies. However potential causes of error were identified in all 4 cases. Confident diagnosis comprises a combination of positive test feed and an 'in house US' in an alkalotic infant. UGI contrast study should not be used in isolation to diagnose IHPS. If the test feed is negative, strict diagnostic measurements should be observed on US and the pyloric 'tumour' palpated on table under anaesthetic before exploration.

Human and mouse enteric nervous system neurosphere transplants regulate the function of aganglionic embryonic distal colon

BACKGROUND & AIMS

Recent advances have raised the possibility of treating enteric nervous system (ENS) disorders with transplanted progenitor cells (ENSPC). Although these cells have been shown to migrate and differentiate after transplantation, no functional effects have been demonstrated. We therefore aimed to investigate whether embryonic mouse and neonatal human ENSPC can regulate the contractility of aganglionic bowel.

METHODS

Embryonic mouse and neonatal human ENSPC were grown as neurospheres before transplantation into aganglionic embryonic mouse hindgut explants and culture for 8-12 days. Engraftment and neural differentiation were confirmed using immunofluorescence and transmission electron microscopy. The contraction frequency of transplanted bowel was measured and compared with that of embryonic day 11.5 embryonic ganglionic and aganglionic bowel cultured for the same period. Calcium movement was measured at spatially defined points in bowel wall smooth muscle. Neural modulation of bowel contractility was assessed using tetrodotoxin.

RESULTS

Both mouse and human ENSPC migrated and differentiated after neurosphere transplantation. Transmission electron microscopy demonstrated the existence of synapses. Transplantation restored the high contraction frequency of aganglionic bowel to the lower rate of ganglionic bowel. Calcium imaging demonstrated that neurosphere transplantation coordinates intracellular free calcium levels. Both these effects were reversed by the addition of tetrodotoxin, indicating the functional effect of neurosphere-derived neurons.

CONCLUSIONS

Neonatal human gut is a source of ENSPC that can be transplanted to restore the contractile properties of aganglionic bowel by a neurally mediated mechanism. This may aid development of a stem cell-based treatment for Hirschsprung's disease.

Neonatal testicular torsion--a lost cause?

Twenty-four neonates presented with signs of testicular ischaemia over a 13-year period. They had a mean birth weight of 3.706 kg. The right testicle was affected in 13, the left in 9 and there was bilateral torsion in 2 babies. Two babies had no twist in the cord, but the testicles were nonviable macroscopically and microscopically. Twenty-one babies had primary exploration revealing necrotic testes in all patients and they underwent orchidectomies. The other three babies had conservative management and the affected testes had atrophied on follow-up. Sixteen babies had contralateral orchidopexy. Doppler ultrasound scans were reported as normal in 2 of 13 babies who had scans. No testes were salvaged following surgery.

CONCLUSION

The incidence of testicular torsion in the neonatal period was calculated as 6.1 per 100,000 live births. No testis was salvaged following surgery in our series of 24 patients. This dismal outcome underlines that immediate surgical exploration, although commonly performed, rarely saves torted testes.

Orchidopexy for undescended testis in England: is it evidence based?

BACKGROUND

Current evidence-based recommendations are that orchidopexy for undescended testis should be performed before 18 months of age. We examined hospital episode statistics data for all orchidopexies performed in England over a 9-year period to see how well this guideline was implemented in current practice and examine trends.

METHODS

Hospital episode statistics data were extracted from 1997 to 2005. Boys with both an Office of Population, Census and Surveys Fourth Revision code for orchidopexy and an International Classification of Diseases, 10th Revision code for undescended testis were included.

RESULTS

Four thousand ninety-four (+/-21) orchidopexies were performed annually. Between 1997 and 2005, the proportion of boys who were younger than 2 years at the time of orchidopexy increased from 15.8% to 28.5% (P < .005, chi(2) test). When adjusted for age and population, there was a secondary peak of incidence at 8 to 10 years. Overall, 46.0% of procedures were performed by paediatric surgeons, 32.1% by general surgeons, and 21.2% by urologists. Over the 9-year study period, an increasing proportion of orchidopexies were performed by paediatric surgeons (P < .001, chi(2)).

CONCLUSIONS

Only 1 in 5 boys is operated on at an "evidence-based" age. The trend has been for more boys to receive surgery at an appropriate age, although the level remains unacceptably low. The reasons are likely to be multifactorial but may partly be explained by secondary testicular ascent.

Early adult outcome of the Duhamel procedure for left-sided Hirschsprung disease--a prospective serial assessment study

PURPOSE

To assess both early adult functional outcome and change in long-term functional outcome over time after the Duhamel procedure (DP) for left-sided Hirschsprung disease (HSCR).

METHODS

The study population consisted of 78 children (aged 19.9 +/- 3.6 years) who previously underwent objective outcome assessment after DP was performed for HSCR during the period of 1980 to 1991. Inclusion criteria were previous evaluation of functional outcome and either rectosigmoid or left-sided HSCR. Outcome measures were assessed twice within the cohort, in 1997 and in 2005. The primary outcome measure was the Rintala (J Ped Surg. 1995;30:491-494) functional outcome score (FOS; maximum, 20). Controls consisted of 20 age-matched healthy children. Satisfactory functional score was defined as an FOS at or above the 10th percentile of controls (FOS, > or = 17). Secondary outcome measures were the operation failure rate (defined by requirement for a stoma or major reoperative surgery), and enterocolitis rates (defined by intention to treat). Consecutive outcome scores were compared by paired t test. Data were expressed as mean +/- SD, and P < .05 was considered significant.

RESULTS

Operation failure occurred in 9 (11.5%) of 78. Consecutive FOSs were obtained in 40 (57%) of 69. A satisfactory functional score was observed in 23 (58%) of 40 adults as opposed to 33 (47%) of 70 children 8 years previously (P = .02). Satisfactory outcome (defined by satisfactory functional score and lack of enterostomy or major revision pull-through procedure) was observed in 23 (47%) of 49. Previously, this figure was 34 (44%) of 78. Individual paired FOSs showed a significant improvement with time (1997: 14.9 +/- 4.1; 2005: 16.4 +/- 2.8; P = .02).

CONCLUSIONS

At early adult follow-up, the operation failure rate has not changed from that of the same cohort 8 years earlier. However, a significant improvement in individual FOSs was demonstrated.

A prospective randomized trial of the effect of a soluble adhesive on the ease of dressing removal following hypospadias repair

AIM

To determine whether the use of a novel dressing removal technique resulted in shorter removal times, reduced the child's experience of pain and/or reduced parental anxiety when compared to a standard approach.

METHODS

This prospective unblinded randomized controlled trial of 53 consecutive boys undergoing primary hypospadias repair was powered using data from a prior feasibility study. Children were randomized to a standard control dressing (A) or standard dressing plus Cavilontrade mark (B) group. Removal was by (A) soaking the child and dressing in the bath or (B) application of an adhesive remover to the dressing. The primary outcome measure was dressing removal time. Secondary measures were: child pain scores on a visual analogue scale measured by the parent and nurse, and parental anxiety using the self-evaluative state anxiety measure. Data are expressed as median (range); P<0.05 is significant.

RESULTS

Dressing B was significantly quicker to remove than A: B 30 min (5-86 min) vs A 40 min (17-105 min), P=0.01, Mann-Whitney. No differences in parent/nurse pain scores between the two groups were seen. There was a strong correlation between parent and nurse reporting of pain scores at the time of dressing removal (Spearman 0.79, P<0.000). No significant differences in pre- and post-dressing removal parental anxiety scores were seen (P=0.159, Mann-Whitney). Several parents had high anxiety levels at both times.

CONCLUSION

The novel dressing removal approach (B) was significantly shorter than the standard one (A). There were no significant differences in child's pain or parental anxiety score between the two approaches.

Characterisation and transplantation of enteric nervous system progenitor cells

AIMS

Enteric nervous system (ENS) progenitor cells have been postulated to be an appropriate source of cells for the treatment of Hirschsprung's disease. In order for this to be successful, the techniques previously used for the isolation of rodent ENS progenitor cells need to be adapted for postnatal human tissue. In this paper, we describe a method suitable for the preparation of both mouse and human postnatal ENS progenitor cells and assess their transplantation potential.

METHOD

Single cell suspensions were isolated from 11.5 days post-coitum embryonic mouse caecum and postnatal human myenteric plexus. These cells were cultured under non-adherent conditions to generate neurospheres which were implanted into aganglionic embryonic mouse hindgut explants. Cell proliferation, migration and differentiation were observed using immunofluorescence microscopy.

RESULTS

Neurospheres generated from both mouse and human tissues contained proliferating neural crest-derived cells that could be expanded in tissue culture to generate both glial cells and neurons. When implanted into aganglionic murine gut, cells migrated from the neurospheres using pathways appropriate for cells derived from the neural crest, and differentiated to become glia and neurons expressing neuronal phenotypic markers characteristic of the ENS including nitric oxide synthase and vasoactive intestinal polypeptide.

CONCLUSION

We have developed a technique for the isolation and expansion of ENS progenitor cells from human neonates. These cells have the ability to differentiate into neurons and glia when transplanted into aganglionic gut, this demonstration being a necessary first step for their autologous transplantation in the treatment of Hirschsprung's disease.

Umbilical pyloromyotomy: comparison of vertical linea alba and transverse muscle cutting incisions

BACKGROUND

Pyloromyotomy is commonly performed through a supraumbilical skinfold incision. Entry into the peritoneal cavity can be achieved via a vertical linea alba incision or a transverse muscle cutting approach. The aim of this study was to compare the morbidity associated with these 2 operative techniques.

METHODS

Case records of all babies undergoing umbilical pyloromyotomy between January 2000 and December 2004 were retrospectively compared for postoperative dehiscence, mucosal perforation, and wound infection (defined by the need for antibiotics or wound exploration). Data were analyzed with GraphPad Prism contingency tables and results were compared by Fisher exact test (P < .05).

RESULTS

During the study period, 341 umbilical pyloromyotomies were performed at our institution. The surgeon was permitted choice of either operative approach (219 vertical linea alba, and 122 transverse muscle cutting). There were no significant differences between the 2 groups regarding age at presentation, sex, duration of symptoms, biochemical derangement, and operator seniority. No significant differences in morbidity were encountered with either of these 2 operative strategies.

CONCLUSIONS

This study demonstrates that the vertical linea alba and transverse muscle cutting incisions have equivalent postoperative morbidity. These findings indicate that neither technique is demonstrably superior.

Less is best? The impact of urokinase as the first line management of empyema thoracis

To assess the impact of intrapleural urokinase and small tube thoracostomy on the management of childhood empyema thoracis. The study population included 38 children presenting consecutively to a regional surgical unit with empyema thoracis from January 2001 to December 2003. Children with malignancy, immunodeficiency and complex intercurrent illness were excluded. Primary outcome variables were the need for second intervention and duration of stay, with other variables including duration of antibiotics, serial CRP and amelioration of pyrexia. Interventions were: tube thoracostomy (16-20 Fr) alone (n=2), tube thoracostomy (6-10 Fr)+urokinase (n=17), thoracoscopy (tube: 20-24 Fr) (n=9), thoracotomy (tube: 16-24 Fr) (n=10). There were no differences in age, weight or length of prodromal symptoms, between treatment groups. There were no differences in primary outcome variables, although no child undergoing thoracotomy required further intervention. The duration of intravenous antibiotics was similar in all groups. Amelioration of pyrexia was more rapid in children undergoing thoracotomy. There were no differences seen with regard to decline in CRP level. Small tube thoracostomy and intrapleural urokinase had a similar outcome to more invasive therapies such as thoracotomy or thoracoscopy thereby supporting the evidence base for urokinase and tube drainage as first line intervention.

Laparoscopic repair of late presenting congenital diaphragmatic hernia

Congenital diaphragmatic hernia usually presents in the neonatal period, with delayed presentation being uncommon. Traditionally repair was performed by laparotomy or thoracotomy. We have performed laparoscopic repair of a previously undiagnosed congenital diaphragmatic hernia that presented acutely in a 10-year-old male. Laparoscopic repair of late-presenting congenital diaphragmatic hernia is a safe and effective approach even in an emergency. The laparoscopic approach has advantages including reduced hospital stay, excellent visualisation of the defect even for obese patients, and improved cosmesis.

Two brothers with Goldberg-Shprintzen syndrome

Goldberg-Shprintzen syndrome is a rare autosomal recessive condition that describes the association of Hirschsprung disease with microcephaly, developmental delay and characteristic facies. We describe two brothers from a non-consanguineous family who have classical features of Goldberg-Shprintzen syndrome. The novel findings in this instance are of foot anomalies including camptodactyly and clinodactyly of the 2nd to 4th toes, which have not been previously described in Goldberg-Shprintzen syndrome.

Trends in paediatric circumcision and its complications in England between 1997 and 2003

BACKGROUND

It has been suggested that too many English boys undergo circumcision. This report describes how circumcision rates have changed in England between 1997 and 2003, including data on complication rates and on how age, medical indication and surgical specialty affect postoperative haemorrhage rates.

METHODS

Data were extracted from the Hospital Episode Statistics database of admissions to National Health Service hospitals in England. Patients were included in the study if an Office of Population Censuses and Surveys version 4 code for circumcision was present in any of the operative procedure fields of the database; 75 868 boys below 15 years of age were included in the study.

RESULTS

Circumcision rates declined by about 20 per cent, from 2.6 per 1000 boys per year in 1997 to 2.1 in 2003. Between 2000 and 2003, circumcision rates remained static at 2.1 per 1000 boys per year. Circumcision rates fell by 31.2 per cent for boys aged 0-4 years, 9.3 per cent for boys aged 5-9 years and increased by 7.7 per cent in boys aged 10-14 years; 90.2 per cent of circumcisions were done for phimosis and 1.2 per cent of boys experienced a complication.

CONCLUSION

Circumcision rates in England continued to fall up until 2000, particularly in those aged under 5 years, in whom pathological phimosis is rare. The circumcision rate remains five times higher than the reported incidence of Phimosis.

Functional outcome and quality of life in anorectal malformations

BACKGROUND/PURPOSE

The aim of this study was to assess the early functional outcome and quality of life (QOL) in children with anorectal malformations.

METHODS

Children treated for anorectal malformations (ARMs) from 1994 to 2000 were evaluated if 4 years or older. Primary outcome measures were bowel function score, assessed by functional outcome questionnaire, and QOL using the Pediatric Quality of Life Inventory (PedsQL 4). The secondary outcome measure was age at potty training. Twenty healthy children were used as controls for functional outcome and age at potty training. Data are reported as mean (SD) unless otherwise stated.

RESULTS

Eighty children were evaluated during the study period. The mean age at follow-up was 82 months (18.7). The response rate was 76.3% (58/76) for bowel function and 77.5% (62/80) for QOL questionnaires. Functional outcome score (maximum 20) decreased significantly with increasing severity of the ARM (male perineal fistula, 16 [3]; female perineal fistula, 15 [3]; rectourethral fistula, 12 [4]; vestibular fistula, 13 [3.5]; bladder neck fistula, 6 [2]; analysis of variance, P = .001). However, there was no difference in QOL between patients with ARM and controls. There was no correlation between age and either bowel function score (Pearson r2 = 0.06) or QOL (Pearson r(2) = 0.12). Affected children took significantly longer to achieve potty training for bladder (35 [13.8] months vs 26 [8.7] months for controls [t test, P = .005]) and bowels (38 [16] months vs 25 [7] months [t test, P = .001]).

CONCLUSION

Children with ARMs have significantly worse bowel function than their peers, depending on the type of lesion. Despite these findings, QOL was not significantly impaired. No correlation was demonstrated between age and either functional outcome or QOL.

Comparison of functional outcomes of Duhamel and transanal endorectal coloanal anastomosis for Hirschsprung's disease

PURPOSE

The aim of this study was to determine the morbidity and medium-term functional outcome of the Duhamel operation and laparotomy and transanal endorectal coloanal anastomosis (TECA) for Hirschsprung's disease (HSCR).

METHODS

The study populations were 34 consecutive children who underwent the Duhamel operation (or Lester Martin modification) and 37 who had the TECA. Demographic details were obtained by case note review, and functional outcome was determined by a combination of outpatient interview, questionnaire, and telephone enquiry.

RESULTS

There was no difference between the groups with respect to age, gender, and length of aganglionic segment. Seventy percent presented as neonates (Duhamel, 24 of 34; TECA, 26 of 37). A single-stage primary pull-through was performed in 17 of 37 children in the TECA group, and in 1 of 34 from the Duhamel group. There was a single perioperative death in the Duhamel group and an unrelated, late death in the TECA group. Postoperative enterocolitis was seen in 13 of 37 TECA children and in a single child from the Duhamel group. A stricture of the pull-through segment was seen in 7 of 37 children after TECA and required temporary diversion in 2 of 9. Late division of a rectal spur was required in 6 of 33 Duhamel children. Requirement for late myectomy was the same in both groups (Duhamel 3 of 33, TECA 4 of 37). Complications requiring stoma formation occurred in 5 of 37 after TECA and 2 of 33 after the Duhamel operation. Two children from the TECA group and 1 from the Duhamel group remain diverted. One child from each group required a re-pull-through procedure. Two patients were lost to follow-up in the TECA group, leaving 34 children in this group and 33 in the Duhamel group in whom functional outcome could be assessed. Functional outcome was similar in the 2 groups.

CONCLUSIONS

TECA and Duhamel procedures have similar medium-term functional outcomes. TECA has a high incidence of postoperative enterocolitis and transient stricture formation but is suitable for single-stage neonatal treatment of HSCR.

Analysis of the effects of endothelin-3 on the development of neural crest cells in the embryonic mouse gut

BACKGROUND/PURPOSE

Mutations in the endothelin-3 (ET-3) and endothelin-B receptor (EDNR-B) genes cause terminal colonic aganglionosis in mice and are linked to Hirschsprung's disease. These experiments are designed to determine if the development of terminal enteric ganglia depends on changes in proliferation, apoptosis, or differentiation of enteric neural crest (NC) cells in response to ET-3.

METHODS

Gut from embryonic lethal-spotted mice (lacking ET-3) and controls were investigated in vivo. NC-derived cells were identified immunohistochemically and their proliferation, apoptosis and differentiation monitored by bromodeoxyuridine incorporation, the terminal deoxytransferase poly dU nick end labelling (TUNEL) reaction, and appearance of neuronal nitric oxide synthase (NOS), respectively.

RESULTS

No differences in apoptosis or proliferation of NC cells were apparent between lethal-spotted embryos and controls. Although no temporal differences in the differentiation of NOS neurones were evident, these cells appeared more cranially in the gut in the absence of ET-3 than in controls.

CONCLUSIONS

ET-3 has no detectable influence on proliferation, apoptosis, or timing of differentiation of NC-derived cells in the gut. However, the more proximal location of differentiated neurones in the absence of ET-3 is consistent with a restricted role in migration of NC-derived cells.

After the honeymoon--medium-term outcome of antegrade continence enema procedure

PURPOSE

The aim of this study was to determine medium-term outcomes of the antegrade continence enema (ACE) procedure.

METHODS

A retrospective casenote review plus telephone questionnaire was conducted. The study was performed at a regional paediatric surgical centre. The subjects were consecutive children undergoing the ACE procedure over a 5 year period. Main outcome measures were use of the ACE; reversal rates; complications, ease of use, effectiveness, and satisfaction scores. Data are expressed as median (range).

RESULTS

Thirty-two (52%) of 62 children undergoing the ACE procedure were girls. The age at the time of operation was 11.5 (3.8 to 17.6) years. Underlying diagnoses included spina bifida (n = 31), anorectal malformations (n = 15), slow-transit constipation (n = 9), Hirschsprung's disease (n = 2), sacral agenesis (n = 2), and trauma/tumour (n = 2). Median follow-up was 5.4 (3.25 to 8.25) years. Eleven of 62 (18%) children were no longer using the ACE (n = 5) or had it surgically reversed (n = 6; 14.1 +/- 9.3 months postprocedure). Reasons for disuse/reversal were lack of effectiveness (n = 4), complications (n = 2), noncompliance (n = 3), independent continence (n = 1), and pain (n = 1). Five (8%) children currently have a colostomy. Gender (P =.31; Fisher's Exact), age (Pearson), and underlying diagnoses (P =.07, Chi2) were not predictors of failure. Overall, stomal stenosis was the most common complication, affecting 26 of 62 (41%) children. Of 32 questionnaire respondents to linear scores, ease of use was rated as 2 (0 to 8, 0, very easy; 10, very difficult), discomfort on use as 3 (0 to 9; 0, no pain; 10, very painful), overall satisfaction as 9 (0 to 10; 0, completely dissatisfied; 10, completely satisfied). Eighty-four percent were completely continent or had soiling less than once a month. There was a significant correlation between the level of continence and satisfaction with the procedure (P =.04; Pearson).

CONCLUSIONS

The ACE procedure offers significant benefits to some children with incontinence or intractable constipation. However, it is not universally successful, and other continence promoting strategies may need to be considered.

Location of stem cells for the enteric nervous system

Hirschsprung disease is the result of aganglionosis of a variable length of the terminal bowel, which arises from the incomplete colonisation of the embryonic gut by vagal neural crest-derived cells (NCC) that migrate caudally from the pharyngeal gut to the rectum. We have previously shown that a very small group of NCC, at the leading edge of this wave of migration, can proliferate and differentiate to innervate the entire distal gut. It remains unknown if this capability is unique to those cells at the leading edge of NCC migration. The hypothesis tested was that NCC capable of acting as stem cells are found throughout the developing enteric nervous system (ENS). Gut was taken from mice at embryonic day 11.5 as the leading edge of NCC migration enters the colon. Terminal colon was separated as aganglionic recipient gut and its rostral end juxtaposed to the caudal end of the small intestine or caecum. The explants were cultured on nitrocellulose filters for up to 120 h, after which time the apposed segments had fused. The gut was then fixed and examined by immunohistochemistry to detect the neuronal markers PGP9.5 and nitric-oxide synthase (NOS) to assess development of enteric ganglia. NCC migrated from the proximal gut into the terminal colon, colonising it along its entire length. The pattern of NCC colonisation and differentiation of NOS-positive neurons was the same, regardless of whether the NCC were derived from the leading edge of migration in the caecum or from more proximal regions of the small intestine. Vagal NCC have the capacity to migrate into separated aganglionic terminal colon and differentiate into neurons. NCC at the leading edge of migration and those located more proximally within the gut demonstrate equivalent ability to migrate to and differentiate in the terminal rectum. Further studies are required to confirm which of these migrating NCC have the properties of ENS stem cells.

Localization and endothelin-3 dependence of stem cells of the enteric nervous system in the embryonic colon

BACKGROUND/PURPOSE

The aganglionosis in a variable length of the distal gut found in Hirschsprung's disease results from the abnormal prenatal development of neural crest-derived stem cells of the enteric nervous system. The cytokine endothelin-3 is necessary for successful colonization of the distal gut, but the location of this interaction with neural crest-derived stem cells remains to be established. The hypothesis tested here is that the stem cells of the enteric nervous system (ENS) in the colon are located at the leading edge of the migrating wave of neural crest-derived stem cells and that these cells require colonic endothelin-3 for complete colonization of the gut.

METHODS

Explants of 11.5-day-old embryonic intact mouse gut and isolated colon were cultured for 72 hours in the presence and absence of the endothelin-B receptor antagonist, BQ788. Specimens then were sectioned and stained by immunohistochemistry to assess enteric nervous system development.

RESULTS

Isolated colon contained a very low number (mean, 73 cells; range, 37 to 106; n = 8) of neural crest-derived stem cells, which had just entered its proximal end at the leading edge of neural crest cell migration. After 72 hours of culture, progeny of these few neural crest-derived stem cells had colonized the colon at an equivalent ganglionic density to those in intact gut. Furthermore, neuronal differentiation, as shown by the appearance of nitric oxide synthase positive neurons, also was equivalent to intact gut. Blockade of the endothelin-B receptor produced terminal aganglionosis in both isolated colons and intact gut.

CONCLUSIONS

The very small number of cells that first enter the proximal colon at the leading edge of neural crest cell migration have the ability to colonize the entire colon normally in an ET-3-dependent manner. These cells therefore have the functional characteristics expected of the stem cells of the colonic enteric nervous system. Furthermore, the normal development of these cells is dependent on the endothelin-3 expressed by the mesenchymal cells of the colon itself.

Double blind randomised controlled trial of topical glyceryl trinitrate in anal fissure

AIMS

To determine the effectiveness and safety of topical glyceryl trinitrate (GTN) in the management of acute anal fissure in children.

METHODS

Individual children were randomised to receive GTN paste or placebo for six weeks in addition to oral senna and lactulose. Patients took laxatives alone for a further 10 weeks. Each week a research nurse telephoned families to assess pain scores and give advice. Main outcome measures were validated standardised pain scores and time to painless defaecation.

RESULTS

Forty subjects were recruited from 46 eligible children; 31 children completed the trial (13 in the GTN group and 18 in the placebo group). No differences in the proportion of those achieving pain free defaecation with relation to time were seen between the two groups. Similarly, there were no significant differences in pain scores between the two groups over the 16 week study period. However, in both groups pain scores had decreased significantly. There were no differences in the incidence of rectal bleeding, faecal soiling, presence of visible fissure, skin tag, or faecal loading at outpatient review at the time of recruitment, or at 6 weeks and 16 weeks. No serious adverse effects were observed.

CONCLUSIONS

This study suggests that 0.2% GTN paste is ineffective in the treatment of acute anal fissures in childhood. However the overall fissure healing rate is high (84%) with associated reduction in pain scores, suggesting that a nurse based treatment programme can achieve a high rate of fissure healing.

Assessment of protein gene product 9.5 as a marker of neural crest-derived precursor cells in the developing enteric nervous system

The neurons and glial cells of the enteric nervous system (ENS) are derived from the neural crest. To study the developmental events involved in congenital abnormalities of the ENS, it is essential to identify all neural-crest cells (NCC) in the prenatal gut. The low-affinity neurotrophin receptor p75 is currently considered to be a gold-standard marker, but because it is a membrane protein, it is lost during procedures that permeabilise cells that are necessary to identify intracellular components and in apoptosis and cell-proliferation assays. We have therefore assessed the potential of the intracellular neuronal marker protein gene product (PGP) 9.5 as a label for neural-crest-derived precursor cells during gut development. Gut was taken from mouse embryos at 11.5 days post-coitum, at which time NCC had reached the proximal colon. Cellular p75 and PGP9.5 expression was determined by double-labelling immunofluorescence. The leading edge of neural-crest migration was defined as the 10 most distal p75-labelled cells. The neuronal marker PGP9.5 labelled NCC as they migrated along the gut at day 11.5. At the leading edge of migration, over 95% of p75-positive cells also expressed PGP9.5, and all PGP9.5-positive cells were also labelled for p75. PGP9.5 is expressed by at least 95% of neural-crest-derived precursor cells at the leading edge of migration along the gut. Thus, it can be used as a robust marker for developing NCC in the gut.