Development, implementation and prospective evaluation of guidelines for transfer of severely injured children to specialist centres

BACKGROUND

Most injured children are appropriately treated at a district general hospital (DGH), but some require transfer to a specialist centre. The objectives of this study were to develop, implement and evaluate triage guidelines for the rapid recognition of injured children who require transfer.

METHODS

This was a prospective, interventional cohort study of the 592 seriously injured children who presented to five regional DGHs during a 51-month period. A multispecialty steering group representing all participating DGHs developed and implemented the guidelines. Data were collected for 24 months before the guidelines were introduced, over the 3-month implementation period and for 24 months afterwards. Outcome measures were referral and management patterns before and after introduction of the guidelines.

RESULTS

For level I (unstable) patients, after the implementation of guidelines there was a 29 per cent increase in the proportion of transfers to a specialist centre (from 40 (68 per cent) of 59 to 32 (97 per cent) of 33; P = 0.003), no admissions to a DGH intensive care unit and all 12 operations were performed at a specialist centre. Guideline users indicated that they were familiar with the guidelines.

CONCLUSION

The introduction of triage guidelines within an effective communication network was associated with changes in the management of severely injured children.

High quality acute care for the severely injured is not consistently available in England, Wales and Northern Ireland: report of a survey by the Trauma Committee, The Royal College of Surgeons of England

INTRODUCTION

A survey was undertaken to determine the extent to which acute hospitals in England, Wales and Northern Ireland were meeting the acute trauma management standards published in 2000 by The Royal College of Surgeons of England and the British Orthopaedic Association.

METHODS

A questionnaire comprising 72 questions in 16 categories of management was distributed in July 2003 to all eligible hospitals via the link network of the British Orthopaedic Association. Data were collected over a 3-month period.

RESULTS

Of 213 eligible hospitals, 161 (76%) responded. In every category of acute care, failure to meet the standards was reported. Only 34 (21%) hospitals met all the 13 indicative standards that were considered pivotal to good trauma care, but all hospitals met at least 7 of these standards. Failures were usually in the organisation of services rather than a lack of resources, with the exception of the inadequate capacity for admission to specialist neurosurgery units. A minority of hospitals reported an inability to provide emergency airway control or insertion of chest tube. The data have not been verified and deficiencies in reporting cannot be excluded.

CONCLUSIONS

The findings of this survey suggest that high quality care for the severely injured is not available consistently across England, Wales and Northern Ireland, and appear to justify concerns about the ability of the NHS to deal effectively with the current trauma workload and the consequences of a major incident.

Primary peritoneal drainage in necrotising enterocolitis: an 18-year experience

Primary peritoneal drainage (PPD) was initially introduced as a method for the pre-operative resuscitation of critically ill infants with complicated necrotising enterocolitis (NEC). Some have recommended it as definitive strategy for a select group of extremely low birth weight babies. The role of laparotomy in neonates who do not respond to initial PPD has also been challenged. With this background, we analysed our experience with the use of PPD in babies with NEC over an 18-year period. We retrospectively reviewed all patients with NEC who had PPD as their initial surgical management over an 18-year period. A total of 122 babies with NEC were treated surgically, of whom 42 had PPD as the initial procedure. There were 28 survivors (67%) in the PPD group, of whom 7 recovered without laparotomy. Twenty-nine infants (69%) had a good clinical response to PPD with 80% (23/29) survival, compared to a 27% survival (3/11) in those who did not respond to drainage. Six patients underwent rescue laparotomy after a poor response to PPD and three of these survived. Six of the 28 pts who underwent laparotomy had isolated intestinal perforation and their clinical characteristics were no different from those with typical NEC. PPD is a useful option in the management of complicated NEC. It is difficult to recognise with certainty those infants who will not require a subsequent laparotomy and therefore we do not support the concept of PPD solely as a definitive strategy. The response to PPD is a good prognostic indicator for ultimate survival. Despite a low salvage rate of 27% in non-responders compared to 80% in responders, there is a role for early laparotomy for those infants who do not respond to PPD.

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.

Gut overgrowth with abnormal flora: the missing link in parenteral nutrition-related sepsis in surgical neonates

BACKGROUND AND AIMS

Patients receiving parenteral nutrition are at risk of septicaemia. Intestinal dysmotility and impaired gut immunity due to parenteral nutrition promote bacterial overgrowth. Gut overgrowth with aerobic Gram-negative bacilli (AGNB) impairs systemic immunity. The aim of this study was to determine the potential role of gut overgrowth with AGNB in the pathogenesis of septicaemia related to parenteral nutrition.

METHODS

A prospective 5 y study of surgical infants less than 6 months of age was undertaken. Surveillance samples of the oropharynx and gut were obtained at the start of parenteral nutrition and thereafter twice weekly, to detect AGNB carriage. Blood cultures were taken on clinical indication only.

RESULTS

Two-hundred and eight infants received parenteral nutrition for 6271 days (median 13 days, range 1-512 days). The incidence of AGNB carriage was 42%, whilst the septicaemia rate was 15%. Eighty-four percent of septicaemic infants carried AGNB, whilst 16% never carried AGNB (P<0.005). Carriage developed significantly earlier than septicaemia.

CONCLUSIONS

The incidence of septicaemia was significantly greater in the subset of abnormal carriers. Although gut overgrowth with abnormal flora reflects illness severity, the fact that it preceded septicaemia implicates AGNB overgrowth, per se, as a contributory factor in the development of septicaemia related to parenteral nutrition. Prevention is unlikely to be successful if it ignores the abnormal flora.

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.

Infection rates in surgical neonates and infants receiving parenteral nutrition: a five-year prospective study

We performed a prospective, observational, cohort study on 208 surgical neonates and infants between 1992 and 1997. Surveillance cultures of the oropharynx and rectum were obtained at the start of parenteral nutrition and thereafter twice weekly. Blood cultures were taken on clinical indication only. Microbial translocation was diagnosed when the micro-organisms in the blood were not distinguishable from those carried in the oropharynx and/or rectum. Liver function was monitored weekly and when septicaemia was suspected. The incidence of septicaemia was 15%. The predominant micro-organisms (86%) were the low-level pathogens, coagulase-negative staphylococci and enterococci. Potential pathogens, including aerobic Gram-negative bacilli, were responsible for the remainder. Microbial translocation was responsible for 84% of septicaemic episodes in 76% of patients. The potential pathogens caused septicaemia significantly later than coagulase-negative staphylococci, at a time when liver function was significantly more impaired. In neonates and infants receiving parenteral nutrition, septicaemia is mainly a gut-derived phenomenon and requires novel strategies for prevention.

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.

Trends in the management and outcome of jejuno-ileal atresia

The aim of this study was to evaluate contemporary patterns of presentation and trends in the management and outcome of newborn infants with jejuno-ileal atresia at a regional paediatric surgical centre in the United Kingdom. The hospital neonatal surgical registry was used to identify patients with jejuno-ileal atresia (n = 83) admitted between 1976 - 1998, excluding those associated with gastroschisis. The clinical records were reviewed and antenatal information, patient demographics, associated anomalies, operative treatment, post-operative management and outcomes were analysed in three time periods to identify trends in management and survival: Group 1 1976 - 1982 (n = 32), Group 2 1983 - 1990 (n = 21), and Group 3 1991 - 1998 (n = 30). Overall survival was 90 %. The number of patients with associated anomalies were Group 1, 10 (31 %); Group 2, 7 (33 %); and Group 3, 11 (37 %). Cystic fibrosis was encountered in 4 (13 %), 1 (5 %) and 4 (13 %) patients, respectively. Resection with primary anastomosis was the definitive management in most of patients: Group 1, 25 (78 %); Group 2, 17 (81 %); and Group 3, 27 (90 %). Initial stoma followed by delayed primary anastomosis was performed in 14 infants; eight patients had divided stomas while 6 had Bishop-Koop stoma. Tapering was used in 10 patients (12 %) with proximal jejuno-ileal atresia. Parenteral nutrition was increasingly utilised over the three time periods studied. There were no deaths in Group 3 compared to 6 deaths in Group 1 and 2 in Group 2 (P = 0.02). Most of the deaths were due to overwhelming sepsis. Mortality did not correlate significantly with the TYPE of atresia, presence of associated anomalies or the need for long-term total parenteral nutrition. The overall complication rate in survivors was 18 %. In the infants undergoing Bishop-Koop operation the complication rate was 50 %. This study has shown a significant reduction in mortality from jejuno-ileal atresia, which may be attributed primarily to advances in perioperative management, including parenteral nutrition. Generous resection of the atretic segment with primary anastomosis is more frequently employed in preference to initial stoma formation. Cystic fibrosis remains an important co-morbid condition that must be excluded promptly in all newborns.

Magnetic resonance venography in assessing venous patency after multiple venous catheters

BACKGROUND/PURPOSE

Venous thrombosis is a well-recognised complication of central venous catheters (CVC). The aim of the study was to assess the value of magnetic resonance venography (MRV) in assessing venous patency in children with suspected venous thrombosis.

METHODS

Contrast studies through the CVC (linogram) and Doppler ultrasonography were the initial investigations performed in children with suspected CVC-related thrombosis. Two-dimensional gated inflow and phase contrast MRV also was performed to assess the extent of venous thrombosis and to locate patent veins for replacement CVC. When the MRV identified a suitable patent vein, the CVC was reinserted by direct venous cut down or the percutaneous method under a general anaesthetic.

RESULTS

A total of 25 children (median age, 5 years; range, 2 months to 17 years) who had multiple CVC insertions (median, 3; range, 1-9), underwent MRV for suspected venous thrombosis. Of 10 patients in whom the catheter was completely occluded, MRV identified extensive thrombosis of the central veins in 6. In 7 other children the linogram showed adherent thrombus at the tip of the CVC only. In 5 of these 7 children MRV showed extensive thrombosis of the vein in which the catheters were placed. Doppler ultrasonography diagnosed thrombotic occlusion of the neck veins in 7 children. The MRV studies showed more extensive thrombosis in 4 of these 7 patients. Additionally, MRV showed thrombosis of the intrathoracic veins in 11 patients who had patent neck veins on ultrasound scan. MRV identified a patent vein for reinsertion of CVC in 22 of 25 children. At operation, venous patency was confirmed in 20 patients (91%).

CONCLUSION

MRV in children with suspected CVC-related thrombosis is more accurate than Doppler ultrasonography, and contrast studies for defining the extent of venous thrombosis. MRV correctly shows venous anatomy and patency for reinsertion of CVC.

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.

Phenotypic presentation and outcome of esophageal atresia in the era of the Spitz classification

PURPOSE

The aim of this study was to investigate contemporary patterns of presentation and outcome in newborns with esophageal atresia with or without tracheoesophageal fistula (OA) using modern prognostic criteria to appraise survival.

METHODS

Over a 12-year period (1986 through 1997), 134 patients with OA were admitted to a single institution. Patient demographics, the presence of cardiac defects, other associated abnormalities (VACTERL), surgical intervention, and patient outcome were recorded. To identify and evaluate changes in the pattern of clinical presentation, frequency of associated anomalies and outcome, patients were analyzed during 4 consecutive time periods, 1986 to 1988, 1989 to 1991, 1992 to 1994, and 1995 to 1997.

RESULTS

A primary repair or delayed primary repair was performed in 113 (84%) patients, with a staged procedure in 19 (14%). Two babies with trisomy 18 did not undergo surgery. Thirty-eight newborns (28%) had a major cardiac malformation (excluding patent ductus arteriosus, unless needing ligation), and 25 (19%) had recognized VACTERL associations. There was a significant increase in the proportion of infants with major cardiac defects diagnosed over the study period, 5 of 34 patients between 1986 and 1988 to 19 of 41 patients between 1995 and 1997 (chi(2) test, P <.001), but the incidence of VACTERL associations remained unchanged. Overall survival rate was 86% in those who underwent surgery. The relative risk of mortality in patients with major cardiac disease and VACTERL associations was 3.47 (95% CI; 1.51 to 7.96) and 2.54 (95% CI; 1.14 to 4.86), respectively. Birth weight was significantly higher in infants who survived (2.68 kg) compared with those who died (2.16 kg, P =.003). Thirty percent of infants with more than one system abnormality died compared with 8% of infants with 1, system abnormality (P =.004).

CONCLUSIONS

This study has found a significant increase in the frequency of cardiac abnormalities encountered in a cohort of OA patients during the period under review. Cardiac disease and multiple abnormalities carried a substantial increased risk of mortality. In the era of the Spitz classification, the phenotypic presentation is important to accurately assess caseload severity and prognosis.

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.

Does the developing liver inhibit early lung growth in congenital diaphragmatic hernia?

It has been hypothesised that the liver induces lung hypoplasia in congenital diaphragmatic hernia (CDH) by non-compressive intrathoracic growth rather than traditional mass herniation. Utilising a co-culture system, we tested the capacity of liver cells to inhibit lung growth by contact rather than compression. Heart, liver, and lungs were microdissected from normal rat embryos (n > 20 from at least three litters) on day 13.5 of gestation. Monolayer cultures of enzymatically dispersed livers and hearts were established at the same cell density. Lung primordia were cultured in direct contact with hepatic cells or partitioned from them by a permeable polytetrafluoroethylene membrane. This permits the contributions of diffusable factors and cell contact to be distinguished. Lungs were similarly cultured in direct contact with or partitioned from cardiac cells. Lungs cultured in isolation served as further controls. Daily inspection permitted assessment of in-vitro lung growth. Growth of lungs in direct contact with hepatic cells was equivalent to that of lungs partitioned from liver cells. Lungs in direct contact with cardiac cells and lungs partitioned from cardiac cells were also not inhibited compared to lungs cultured in isolation. Early lung development is thus not inhibited by humoral or contact-mediated interactions with embryonic liver cells. Lung hypoplasia in CDH is therefore unlikely to originate from contact inhibition with the developing liver. An intrinsic pulmonary defect may better explain hypoplastic lung development in CDH.

Umbilical pyloromyotomy--an alternative to laparoscopy?

AIMS

To evaluate the utility of umbilical pyloromyotomy for infantile hypertrophic pyloric stenosis (IHPS) compared to published series promoting laparoscopy.

METHODS

Eighty-six babies with IHPS had pyloromyotomy using an umbilical skin fold incision. Operating times, post-operative hospital stay and cosmetic appearance of the umbilical wound were studied. Data extracted from recent series promoting laparoscopy were identified using a MEDLINE search strategy and used for comparative analysis.

RESULTS

Mean operating time for umbilical pyloromyotomy was 30 min (range 15-50 min). All patients went home at an average period of 58 h (range 48-72 h) following surgery. The umbilical scar was barely visible in the post-operative period. Laparoscopic pyloromyotomy operating times ranging from 18-41 min (mean overall 30 min) are recorded in the literature. Post-operative stay following laparoscopy has been variable (23-91 h), where reported. In contrast with umbilical pyloromyotomy, "pox" marks observed following port insertions for laparoscopy can give an unsightly scar.

CONCLUSIONS

This study has found that umbilical pyloromyotomy can be performed with minimal morbidity and equivalent operating times to laparoscopy. The shorter hospital stay reported in some series promoting laparoscopy must be balanced against local practice influencing hospital stay, the financial implications of offering a laparoscopic service, the skills needed for laparoscopy, and the short learning curve required by paediatric surgical trainees to become proficient at umbilical pyloromyotomy. The cosmesis of the umbilical incision is excellent. These findings suggest that umbilical pyloromyotomy is a reliable alternative to laparoscopy.

Classification and risk-factor analysis of infections in a surgical neonatal unit

BACKGROUND/PURPOSE

Nosocomial infection may result in significant morbidity in surgical neonates. Traditionally, nosocomial infections are classified using time cut-off points. Gastrointestinal carriage of microorganisms has not been used as a criterion for classifying infection in surgical neonates. The aims of the study were to (1) determine the overall infection rate, (2) distinguish between nosocomial and community acquired infections using a 48-hour postadmission cutoff and the carrier state criterion, and (3) determine risk factors for clinical infection.

METHODS

A 1-year prospective observational cohort study was undertaken in a regional neonatal surgical unit between 1997 and 1998. All infants residing for >/=3 days in the unit were included in the study (n = 167). Patient demographics, including illness severity (PRISM score), were recorded for all infants. Surveillance throat and rectal swabs were obtained on admission and twice weekly thereafter to determine carrier status. Carriage was defined as isolation of the same microorganism from at least 2 consecutive surveillance samples. Infective episodes were diagnosed if a clinical diagnosis of local or general inflammation was microbiologically proven.

RESULTS

A total of 167 infants responsible for 174 admissions were studied. Median gestational age was 38 weeks (range, 24 to 42), median birth weight was 3 kg (range, 1 to 3.6), median age on admission was 8 days (range, 0 to 142), median length of hospital stay was 8 days (range, 3 to 95). The diagnoses were gastrointestinal disorders (n = 96), abdominal wall defects (n = 22), neural tube defects and hydrocephalus (n = 17), thoracic disorders (n = 16), urologic disorders (n = 12), and abdominal tumours (n = 4). Twenty-five infants had 33 episodes of infection giving an overall infection rate of 14.9%. The predominant infecting organism was Stapylococcus aureus (n = 11); others were enterococcus, coagulase negative staphylococcus, Candida spp, Gram-negative bacilli, and anaerobes. A total of 27 of 33 infective episodes were caused by microorganisms carried by the infants on admission (primary endogenous). Only 6 children had "true" nosocomial infections. Using a traditional 48 hour cutoff, 87% of the infections were classed as nosocomial. Birth weight, presence of central venous line, PRISM score, and length of stay were identified as significant risk factors for developing clinical infection.

CONCLUSIONS

(1) Carriage allowed us to identify the true nosocomial infection rate (microorganisms acquired in the unit), which was only 18%. In contrast, using a traditional 48 hour cutoff, 87% of the infections would have been classed as nosocomial and warranted unnecessary cross-infection investigations. (2) The results of this study confirm that birth weight, illness severity (PRISM score), presence of central venous catheter, and length of hospital stay were independent risk factors associated with clinical infection in surgical neonates.

A stratified response system for the emergency management of the severely injured

A decade ago, there were justifiable criticisms of the delivery of emergency care for injured patients in accident and emergency departments in the UK. To address this, a trauma management system was developed in 1991 at Alder Hey Hospital, Liverpool. This includes a trauma team, communication system, management guidelines and quality assurance. On admission to the accident and emergency department, injured patients are triaged to one of three levels of injury severity, and a multidisciplinary team lead by a paediatric surgeon or senior accident and emergency department physician is activated. The level of injury severity determines the composition of the trauma team. A care pathway based on ATLS/APLS principles has been developed. The response process as well patient management are documented and reviewed at a monthly audit meeting. Currently, more than 80% of eligible patients are managed using the trauma system, with an over-triage rate of about 25%. Regular modifications to the trauma system since its inception in 1991 have resulted in an efficient and effective management structure. Stratification of the trauma response has minimised unnecessary use of the multidisciplinary trauma team and ensures that mobilisation and use of hospital staff and resources are tailored to the needs of the injured patient. Although developed in a specialist children's hospital, the system could be adapted for any acute hospital.

Transanal endorectal coloanal surgery for Hirschsprung's disease: experience in two centers

BACKGROUND/PURPOSE

Transanal mucosal proctectomy with low coloanal anastomosis has been used widely in the treatment of rectal malignancies, ulcerative colitis, and familial polyposis. The use of this technique for Hirschsprung's disease is a relatively new concept. The aim of this study was to evaluate and compare the results of transanal endorectal coloanal anastomosis (TECA) for Hirschsprung's disease from 2 centers.

METHODS

All children who underwent TECA for Hirschsprung's disease at Alder Hey Children's Hospital, Liverpool, England from January 1995 to December 1998 (n = 41) and the Children's Hospital, Helsinki, Finland from June 1988 to December 1998 (n = 95) were evaluated. Patient demographics, age at diagnosis, initial management, length of aganglionic segment, and age at operation were documented. Postoperative complications and functional outcome were analyzed.

RESULTS

Patient demographics were similar in the 2 centers. Age at diagnosis was less than 1 month in 71% of children at Liverpool, compared with 53% at Helsinki. Sixteen (39%) patients in Liverpool and 75 (79%) patients in Helsinki underwent primary TECA without colostomy. Postoperative enterocolitis occurred in 14 of 136 patients (10%). An ischemic stricture of the colon was documented in 4 children in the Liverpool series, 2 of whom had TECA as a salvage procedure after a previously failed Duhamel pull-through operation. Frequency of bowel movements, seen in the immediate postoperative period in most patients gradually improved with time from a median of 5 (range, 2 to 12) bowel movements a day at 3 months after TECA to 2 (range, 1 to 6) bowel movements a day at 2 years' follow-up. Assessment of continence was possible in 51 of 136 patients (37%) over the age of 4 years. Thirty-nine children had normal bowel function giving an overall success rate of 76%.

CONCLUSIONS

Transanal endorectal coloanal anastomosis is a good technique for treatment of Hirschsprung's disease with few operation-related complications. Based on the data emerging from these 2 centers the functional outcome is highly satisfactory and comparable with other established procedures.

In vitro effects of growth factors on lung hypoplasia in a model of congenital diaphragmatic hernia

BACKGROUND/PURPOSE

Pulmonary hypoplasia, a leading contributor to the lethality of congenital diaphragmatic hernia (CDH), precedes diaphragmatic malformation in the nitrofen model and persists to allow experimental manipulations in organ culture. Fibroblast growth factors (FGFs) are crucial to early lung development. Acidic FGF (FGF-1) binds to all FGF receptors and enhances in vitro branching morphogenesis. Basic FGF (FGF-2) is localized to developing airway epithelium, basement membrane, and extracellular matrix. Heparin (HEP) modulates FGF kinetics and inhibits smooth muscle proliferation in lung primordia. The aim of this study was to examine the morphological effects of fibroblast growth factors and heparin on lung hypoplasia in an organ culture model.

METHODS

Sprague-Dawley rats were fed nitrofen on day 9.5 of pregnancy to induce lung hypoplasia and CDH in newborns. Control rats received olive oil. Normal and hypoplastic lung primordia were microdissected on day 13.5 of gestation and cultured up to 78 hours in plain media with or without FGF-1 or FGF-2, with or without HEP. In vitro morphological development was studied by serial measurements of terminal bud count, lung area, and lung perimeter.

RESULTS

Over 120 fetal lung specimens were studied (n > or = 4 per group). Significant increases in area, perimeter, and bud count were seen in normal lungs cultured with FGF-1 plus HEP compared with control media (P < .05). In the nitrofen lungs, FGF1 plus HEP yielded reductions in all parameters compared with those in control media (P < .05), whereas FGF-2 produced significant expansion in lung area but marked reductions in bud count and lung perimeter divided by square root of area (P < .05). Heparin did not produce substantial or sustained alteration of morphology in normal or hypoplastic lungs.

CONCLUSIONS

These observations may indicate an intrinsic abnormality of FGF processing in the hypoplastic nitrofen lung before diaphragmatic malformation. Heparin did not rescue abnormal lung development. Mechanisms underlying the differential effects of these agents now need to be explored to target fetal lung growth and improve the dismal prognosis of human CDH.

Reduced endothelin-3 expression in sporadic Hirschsprung disease

BACKGROUND

Enteric aganglionosis in Hirschsprung disease has been linked to genes coding for endothelin-3 (EDN3) and the endothelin B receptor (EDNRB), but there is no such linkage in most patients with sporadic Hirschsprung disease. However, the similarity between the distal colonic aganglionosis in Hirschsprung disease and that due to EDN3 or EDNRB mutations led to the hypothesis that levels of expression of these genes might be affected in the absence of mutation, thus causing the Hirschsprung disease phenotype. The aim of this study was to determine EDN3 and EDNRB messenger RNA (mRNA) levels in tissue samples from patients with sporadic Hirschsprung disease.

METHODS

RNA and DNA were isolated from the ganglionic and aganglionic colonic segments of ten children with sporadic Hirschsprung disease, and from the colon of ten age-matched controls. The DNA was analysed for mutations in the genes coding for endothelin-3 (ET-3) and endothelin B receptor (ET-B) proteins. Relative levels of EDN3 and EDNRB mRNA were determined by semi-quantitative transcriptase-polymerase chain reaction.

RESULTS

Three children had sequence variants in EDN3 and EDNRB. In the remaining seven patients, EDN3 mRNA levels were reduced in both the ganglionic and aganglionic colon compared with levels in controls; there was no difference in expression of EDNRB between groups.

CONCLUSION

In the absence of mutation, EDN3 is downregulated in short-segment Hirschsprung disease, suggesting that this may be a common step leading to aganglionosis.

Evolving experience in the management of empyema thoracis

The optimal management of paediatric empyema thoracis remains controversial. The objective of the study was to analyse evolving experience in clinical presentation, management, outcome and factors contributing to adverse morbidity in thoracic empyema. Forty-seven patients presenting to a paediatric surgical centre were studied in three consecutive 6-y periods during 1980-97 to compare any change in the pattern of disease influencing diagnosis and management. Patients were categorized into two treatment groups: (i) conservative management (antibiotics and/or tube thoracostomy), (ii) thoracotomy. The median duration of illness prior to hospital admission was 10 d (range 1-42 d). Ultrasound was increasingly utilized in the diagnosis and staging of empyema and played an important role in directing definitive management. The presence of loculated pleural fluid determined the need for thoracotomy. Sixteen of 20 patients (80%) who were initially treated with thoracocentesis or tube thoracostomy eventually needed thoracotomy. There was a positive shift in management towards early thoracotomy resulting in prompt symptomatic recovery. Significant complications were noted in seven children who had delayed thoracotomy. These included recurrent empyema with lung abscess (n = 2), scoliosis (n = 2), restrictive lung disease (n = 1), bronchopleural fistula (n = 1) and sympathetic pericardial effusion (n = 1). An unfavourable experience with delayed thoracotomy during the study period has led us to adopt a more aggressive early operative approach to empyema thoracis. The decision to undertake thoracotomy has been influenced by the ultrasound findings of organized loculated pleural fluid. Delayed surgery was associated with adverse outcome. Whilst fibrinolytics and thoracoscopy may provide attractive options for early empyema, thoracotomy can hasten patient recovery regardless of the stage of disease. Prospective randomized trials are required to assess the ideal therapy for childhood empyema.

Time-dependent effects of endothelin-3 on enteric nervous system development in an organ culture model of Hirschsprung's disease

BACKGROUND/PURPOSE

Terminal colonic aganglionosis (Hirschsprung disease) results from incomplete rostrocaudal colonisation of the embryonic gut by neural crest cells (NCC). Mutations in the genes encoding endothelin-3 (EDN3) or its receptor (EDNRB) have been shown to result in a similar aganglionosis. This article describes the development of an organ culture model using embryonic murine gut to determine how endothelin-3 regulates development of the enteric nervous system.

METHODS

Gut explants from mice of different gestational ages were cultured for up to 3 days in the presence or absence of 5 micromol/L of the specific endothelin-B receptor antagonist BQ788. EDN3 and EDNRB mRNA expression were analysed by reverse-transcription polymerase chain reaction (RT-PCR) and whole-mount in situ hybridisation. NCC were localised using immunoreactivity for PGP 9.5, a specific neuronal marker.

RESULTS

EDN3 mRNA continued to be expressed by caecal mesenchymal cells and EDNRB mRNA by the migrating NCC in culture. Embryonic day (E)11.5 explants were already colonised by NCC up to the terminal ileum. Complete colonisation occurred in organ culture over the next 72 hours (equivalent to E 14.5). Explants of E 12.5 and E 13.5 showed complete colonisation after 48 and 24 hours culture, respectively. Terminal aganglionosis resulted from treatment of E 11.5 and E 12.5 gut explants with 5 micromol/L BQ788, whereas there was no inhibitory effect on E 13.5 explants.

CONCLUSIONS

An organ culture model has been developed in which NCC colonisation of embryonic gut mirrors that described in vivo. Blockade of the EDN3/EDNRB receptor pathway shows that the interaction of endothelin-3 with its receptor is only necessary for NCC colonisation at early time-points, despite the continued expression of endothelin-3 mRNA in the gut.

Cell proliferation and apoptosis in experimental lung hypoplasia

BACKGROUND/PURPOSE

Current treatment for lethal pulmonary hypoplasia in congenital diaphragmatic hernia (CDH) may be hampered by uncertainty over its origin. Herniation of abdominal organs into the chest was thought to produce lung hypoplasia by compression. Experimental CDH models suggest that disturbed lung growth precedes these events. Mammalian development comprises cell differentiation, proliferation and programmed cell death or apoptosis. Could lung hypoplasia in CDH result from alterations in these processes well before visceral herniation takes place? The aim of this study was to compare cell proliferation and apoptosis in normal and hypoplastic embryonic lungs before normal diaphragmatic closure using a CDH model.

METHODS

Sprague-Dawley rats were given 100 mg of nitrofen on day 9.5 of pregnancy to create lung hypoplasia and CDH in newborns (term, 22 days). Control rats received olive oil. Cell proliferation in embryonic lung specimens was measured by bromodeoxyuridine (BrdU) incorporation at 13.5 to 15.5 days' gestation, before normal diaphragmatic closure in this species (day 16.5). Apoptosis was measured by the in situ end-nick labelling (TUNEL) method in lung sections obtained from rat embryos of 13.5 to 16.5 days' gestation.

RESULTS

High levels of cell proliferation were seen in both normal control and nitrofen-exposed lungs. However, 24 hours before normal diaphragmatic closure, nitrofen-exposed lungs had significant reductions in cell proliferation on day 15.5 of gestation (P = .009 v controls). Apoptosis occurred at low levels throughout the developmental stages examined (< 0.3%) without significant differences encountered between the study groups.

CONCLUSIONS

These findings have shown high rates of cell division during normal lung development before diaphragmatic closure. Decreased levels over this critical period in gestation may contribute to early lung anomalies in the nitrofen CDH model. Strategies to promote cell proliferation in the fetal lung may therefore hold future promise in human CDH. Apoptosis appears not to play a major role in hypoplastic lung development. Therapies to inhibit apoptosis would seem unlikely to improve this early lung growth.

Heparin and in-vitro experimental lung hypoplasia

Pulmonary hypoplasia (PH) is a leading contributor to the lethality of congenital diaphragmatic hernia (CDH). Studies now suggest that PH arises prior to visceral herniation. Growth factors (GF) are pivotal to this embryonic lung growth. With striking in-vitro effects on lung morphogenesis, GF are under investigation as therapies for PH. Heparin modulates the kinetics of heparan-sulphate binding ligands that drive lung development. We hypothesised that heparin may rescue PH by favourable alteration of endogenous pulmonary GF activity. Normal and hypoplastic lung primordia were microdissected on day 13.5 of gestation and cultured for up to 78 h in plain media with and without heparin. In-vitro morphological development was studied by serial measurements of terminal bud count, lung area, and lung perimeter. Nitrofen-exposed lungs cultured with heparin showed no significant improvements in terminal bud count, lung area, and lung perimeter at 30, 54, and 78 h compared to untreated hypoplastic lungs maintained in vitro. In normal lungs heparin demonstrated no sustained significant morphological effects compared to untreated control lungs. In this study, heparin did not stimulate branching morphogenesis of normal or hypoplastic lungs in our organ culture system. Known at higher concentrations to inhibit smooth-muscle proliferation, heparin may ameliorate pulmonary vascular hypermuscularisation with the prospect of benefiting CDH infants on extracorporeal membrane oxygenation. Future studies will address the impact of exogenous GF on hypoplastic lung development in organ culture.

The effects of intravenous epidermal growth factor on bacterial translocation and central venous catheter infection in the rat total parenteral nutrition model

Sepsis is a major complication of total parenteral nutrition (TPN) in children. Gut mucosal atrophy (GMA) and bacterial translocation (BT) occur in patients receiving TPN, and the translocated enteric organisms may cause central venous catheter (CVC) infection. Epidermal growth factor (EGF) has a trophic effect on the gut mucosa and may reduce BT, thereby reducing catheter infection. Using a rat TPN model, the relationship between GMA, BT, and catheter sepsis was examined and the effect on these of intravenous EGF was studied. There were four experimental groups. Group 1 had no CVC, Groups 2, 3, and 4 had a continuous central venous infusion as follows: group 2, saline; group 3, TPN; group 4, TPN with EGF. Groups 1 and 2 had free access to chow, groups 3 and 4 had no enteral feeds. After killing at 1 week, blood, tissue, and catheter specimens were cultured and mucosal morphology analysed. BT was defined as the presence of the same organism in cultures from the gut lumen and mesenteric lymph nodes (MLN). TPN only (group 3) resulted in GMA and BT, and 5 of 12 animals with BT had the same gut bacteria in blood and/or catheter cultures. The addition of EGF to the TPN significantly reduced GMA, BT to the MLN, and blood and/or catheter infections (P = <0.05). In animals carrying enterococci, there was a significant reduction in translocation of enterococci (group 3: 8/14; group 4: 0/11; P<0.05) and catheter infection by enterococci was prevented (group 3: 3/14; group 4: 0/11). EGF thus reduced GMA, BT, and blood and/or catheter infection when given IV to rats receiving TPN. Enterococcal translocation and subsequent blood and/or catheter infection was completely prevented, suggesting a selective effect of EGF.

Early lung malformations in congenital diaphragmatic hernia

BACKGROUND/PURPOSE

Lung hypoplasia, a leading contributor to the lethality of congenital diaphragmatic hernia (CDH), has been attributed to compression of the fetal lung by herniated abdominal viscera. Contested findings in experimental CDH suggest that lung malformation may precede diaphragmatic hernia. To address this unresolved question, we studied the pattern and progress of embryonic lung development in vivo and in vitro before diaphragmatic herniation in the nitrofen CDH model.

METHODS

Sprague-Dawley rats were fed nitrofen on day 9.5 of pregnancy to induce pulmonary hypoplasia and CDH in newborns (term, day 22). Control rats received olive oil. Embryonic lungs were microdissected on day 13.5 gestation, 24 hours after lung primordia bud from the foregut (normal diaphragmatic closure, day 16.5). In vivo airway branching was measured by counting terminal lung buds at this stage. Lungs were cultured for up to 78 hours and longitudinal in vitro development studied by serial measurements of terminal bud count, area, and perimeter.

RESULTS

At 13.5 days of gestation in vivo, nearly 99% of normal lungs (n = 130) had > or = 6 terminal lung buds. In contrast, 36% of the nitrofen-exposed lungs (n = 170) fell short of this developmental milestone with less than 6 terminal buds (P < .001). In vitro, the nitrofen lungs had reduced area compared with controls after 6, 30, and 54 hours (P = .001, P < .001, and P = .001, respectively). Bud count and epithelial perimeter were reduced in the nitrofen lungs after 6 and 30 hours in vitro (P < .001 and P = .01 v normal terminal bud count; P < .001 and P= .002 v normal perimeter).

CONCLUSIONS

Before diaphragmatic herniation, nitrofen-exposed embryos in vivo have a 36% frequency of reduced airway branching that strikingly parallels the 30% to 40% term incidence of CDH in this model. The authors propose that this early lung anomaly is restricted to a subset of nitrofen-exposed embryos in which it is integral to an emerging CDH phenotype. In vitro data confirm that nitrofen-induced pulmonary hypoplasia precedes visceral herniation and persists to allow experimental manipulation in culture. The developmental biology underlying lung hypoplasia in CDH may now be addressed using this organ culture system.

A longitudinal study of electrogastrography in normal neonates

BACKGROUND/PURPOSE

Gastric motility is partly regulated by an inherent electric control activity (ECA). Electrogastrography (EGG) measures gastric ECA through cutaneous electrodes. Little is known about EGG in neonates. A slow wave frequency of 3 cycles per minute (cpm) accounts for 85% to 100% of gastric ECA in normal adults and children. However, the authors have shown previously a lower percentage of 3 cpm activity in neonates. Abnormal EGG patterns (tachygastria and bradygastria) have been described in adults and children with gastric motility disorders. In neonates, especially premature infants, disorders of gastrointestinal motility are common, especially after gastrointestinal operations. It is necessary to characterise normal ECA before the pathophysiology of these disorders can be studied. The aim of this study was to investigate the pattern of ECA in the developing neonate.

METHODS

Nine healthy neonates born at 34 weeks' gestation were studied using Synectics EGG sampling at 4 Hz. Each subject underwent 4 hourly EGG recordings at fortnightly intervals from birth until age 8 weeks, and then every 2 months until age 2 years. The paired sample t test (95% Confidence Interval [CI]) was used to compare recordings.

RESULTS

Between birth and age 2 years, 3 cpm activity increased from 38% to 57% of recorded time. The mean percentage recorded time of tachygastria decreased from 47% to 35%, and bradygastria decreased from 15% to 8%. Statistically significant differences were seen between birth, 6 months, and 2 years of age.

CONCLUSIONS

The pattern of ECA in the normal neonatal stomach differs from that seen in adult studies. Tachygastria and bradygastria are seen more frequently, with fewer periods of 3 cpm. There is an increase in the percentage of 3 cpm activity over time, with statistically significant differences from the ECA pattern at birth first seen at the age of 6 months. The authors suggest that neonatal ECA undergoes a maturation process and that larger longitudinal and normal range studies are required to investigate this phenomenon.

The stress process and the social distribution of depression

Mental health generally and depression in particular have been repeatedly shown to vary in relation to gender, socioeconomic status, marital status, and age. These status differences may be linked to mental health because they tend to define important differences in stress exposure and in the availability of coping resources. This paper examines the capacity of the stress-process model to account for the social distribution of depression. We employ mediation analyses using data from a 1990-1991 survey of Toronto community residents. In general, we found hypothesized risk factors to vary across these statuses with depressive symptoms and disorder and the distribution of protective factors to vary inversely. Results indicate that the model as expressed in our analyses accounts for a substantial minority of observed depression differences across individuals and for a considerable portion of reliably observed variation across social statuses. Our findings with respect to major depressive disorder parallel those for depressive symptomatology. Most compelling is the nearly total explanation of the socioeconomic status association with depressive symptoms and the substantial contribution toward explaining the socioeconomic status-disorder relationship when stress process mediators are accounted for.

Personal resources and the social distribution of depression

This paper addresses the hypothesis that gender, age, marital status, and SES matter for depression partly because of associated differences in the availability and/or impact of the personal resources of mastery and self-esteem. It is argued that findings indicating that the social distributions of these resources complement those for depression would provide preliminary support for this hypothesis. Based on a large urban community sample (n = 1,390), our findings fail to support the availability hypothesis in relation to marital status, provide only modest support in reference to age and gender, but yield compelling support in relation to socioeconomic status (SES). Indeed, variations in the availability of these resources, especially mastery, provide a largely, if not entirely, adequate explanation for the SES-depressive symptoms relationship and accounts for nearly half of the SES-Major Depressive Disorder relationship. Although the significance of mastery was more pronounced among women and unmarried persons, such differences did not contribute to understanding observed gender or marital status variations in depression.

Oral contrast with computed tomography in the evaluation of blunt abdominal trauma in children

BACKGROUND

The use of oral contrast in evaluating children by computed tomography (CT) following blunt trauma is controversial. The aim of this study was to evaluate retrospectively the use of oral contrast with abdominal CT in children with suspected abdominal injury.

METHODS

The medical records of 101 children who underwent CT for abdominal trauma between 1993 and 1997 were reviewed for data pertaining to the mechanism of injury, clinical findings and management. Scans were reviewed by a paediatric radiologist and criteria of intestinal injury on CT described by Cox and Kuhn were used: (1) extraluminal air or contrast material, (2) focal area of thickening of bowel wall and mesentery, and (3) free intraperitoneal fluid in the absence of solid organ injury.

RESULTS

CT was performed within a median time of 2.4 (range 1-48) h after the injury. On 37 (62 per cent) of 60 scans in children who had oral contrast, the duodenum was not opacified after a mean delay of 30 min. Intestinal injury was suspected on CT in four children. In two children with CT evidence of intestinal injury (with/without oral contrast) rupture of the duodenojejunal flexure (n = 1) or ileal perforation (n = 1) was found at laparotomy. Two children had a false-positive scan, leading to negative laparotomy; one scan with oral contrast incorrectly suggested a duodenal leak and in another child CT without oral contrast showed thickening of bowel wall with free intraperitoneal fluid but no specific intestinal injury was identified at laparotomy. One patient had two negative CT scans (with and without oral contrast) and underwent laparotomy for clinical suspicion of bowel injury; rupture of the splenic flexure of the colon was found at laparotomy.

CONCLUSION

CT is not reliable for diagnosing intestinal injuries and this is not improved by use of oral contrast. Omission of oral contrast was not associated with delay in the diagnosis of intestinal injury. Since intestinal injuries are uncommon in children, a prospective multicentre study would determine more precisely the role of the routine use of oral contrast.

Ontogeny of interstitial cells of Cajal in the human intestine

BACKGROUND/PURPOSE

Interstitial cells of Cajal (ICC) recently have been identified as intestinal pacemaker cells. Abnormalities in ICC are increasingly recognized in a number of neonatal disorders such as infantile hypertrophic pyloric stenosis, Hirschsprung's disease, and transient intestinal pseudo-obstruction. The aim of this study was to determine the fetal and postnatal differentiation and development of ICC in the human gastrointestinal tract to aid interpretation of pathological specimens.

METHODS

Specimens of human gastrointestinal tract from (1) fetuses (9 to 17 weeks' gestation; n = 12), (2) premature and full-term neonates with non-gut motility-related disorders, (age 26 to 59 weeks' gestation; n = 13), and (3) children (age 4 months to 13 years; n = 7) were immunohistochemically stained with antibodies to c-kit(a marker for ICC) and protein gene product 9.5 (PGP9.5, a marker for neural tissue).

RESULTS

(1) C-kit-positive ICC were present throughout the gut in all specimens including those from the earliest gestational ages. C-kit and PGP9.5 immunoreactivities were present in different cell populations. (2) The distribution of ICC varied with gestational age and with region of the gut. (3) Maturation of ICC networks continues postnatally in a region-specific manner.

CONCLUSIONS

ICC are present from an early stage in human gut development. Interpretation of apparent abnormalities in ICC distribution as being of pathological significance should be tempered by the knowledge that ICC networks continue to develop postnatally and that ICC development varies throughout the gut.

Cardiovascular malformations in experimental congenital diaphragmatic hernia

BACKGROUND/PURPOSE

Newborns with congenital diaphragmatic hernia (CDH) frequently have associated anomalies that have a major impact on survival rate independent of pulmonary hypoplasia and pulmonary hypertension. Cardiovascular malformations (CVM) represent a major group of lethal extrapulmonary abnormalities that often assume greatest prognostic significance in most CDH studies. Animal models resembling human CDH may aid knowledge of the basic embryology that leads to the coexpression of CDH and CVM. This study, therefore, analyzed the incidence and spectrum of CVM in fetal rats with CDH.

METHODS

Left-sided CDH (LCDH) was induced in fetal rats by the maternal administration of 100 mg of nitrofen by gavage on day 9.5 gestation (term, day 22). Control animals received olive oil (OO) and were used for comparative analysis. Fetal rats were harvested by cesarean section on day 21.5 or day 22, histologically processed and examined for CVM.

RESULTS

A significant number of CVM were observed in 15 of 60 (25%) LCDH rats compared with 4 of 60 (6.7%) nitrofen non-CDH rats (P = .01). The spectrum of abnormalities in CDH included ventricular septal (VSD) defects (n = 6), vascular rings (n = 4), anomalous subclavian arteries (n = 3), atrioventricular septal defects (n = 1) and Fallot's tetralogy (n = 1). A VSD (n = 1), double-outlet right ventricle VSD (n = 1) and Fallot's tetralogy (n = 2) were noted in nitrofen non-CDH rats. Control (OO) fetal rats (n = 60) displayed no malformations.

CONCLUSIONS

These results confirm a significant incidence and spectrum of CVM in a teratogenic CDH model similar to that seen in humans with CDH. The findings of this study reinforce the validity of the nitrofen model as a research tool to uncover the genetic and molecular mechanisms responsible for the genesis of CDH and allied malformations.

Long-term outcome and colonic motility after the Duhamel procedure for Hirschsprung's disease

BACKGROUND/PURPOSE

The aim of this study was to investigate long-term functional outcome and colonic motility in children who had undergone the Duhamel-type operation for Hirschsprung's disease (HSCR).

METHODS

All patients (n = 91) who underwent the Duhamel or Lester Martin Modified Duhamel operation for HSCR from 1980 to 1991 were included in the study. Twenty-two healthy age-matched children were used as controls. Functional outcome was assessed by questionnaire (response rate 100%). Total and segmental colonic transit time (CTT) was determined using the saturation method (80% participation rate).

RESULTS

Outcome scores were significantly worse in the study group for patients with rectosigmoid (RS, P < .001), long segment (LS, P < .001), and total colonic (TC) aganglionosis (P < .05), when compared with controls. The CTT was significantly prolonged in the RS group (P = .01) compared with LS, TC, and control groups; this was caused by prolonged "rectosigmoid" transit in the RS group compared with controls (P = .012). There was a positive linear correlation (P = .0002) between age and outcome score in patients with RS disease unrelated to CTT. Nine patients required a late long-term enterostomy. A satisfactory outcome (defined as outcome score > or = 10th percentile of the control group, and absence of stoma or requirement for major revisional surgery) was seen in only 42% of patients overall and in 79% of patients over 14 years of age.

CONCLUSIONS

The Duhamel procedure, in common with other pull-through procedures, is associated with significant long-term morbidity, the aetiology of which is poorly understood.

Intravenous glutamine or short-chain fatty acids reduce central venous catheter infection in a model of total parenteral nutrition

BACKGROUND/PURPOSE

In children receiving total parenteral nutrition (TPN) translocated enteric organisms are a possible cause of central venous catheter infection. The aim of this study was to determine the relationship between gut mucosal atrophy, bacterial translocation, and catheter sepsis in rats receiving TPN alone or supplemented with intravenous short chain fatty acids (SCFA) or glutamine.

METHODS

Mature Wistar rats were studied. Groups 2 to 5 had a central venous catheter inserted. Group 1 (n = 12) had enteral feeds only, group 2 (n = 14) had enteral feeds and intravenous saline, group 3 (n = 15) had TPN only, group 4 (n = 13) had TPN with SCFA, and group 5 (n = 15) had TPN with glutamine. At 1 week, blood, tissue, and catheter specimens were obtained for culture and mucosal morphometry.

RESULTS

Villus height and crypt depth were reduced significantly in group 3 compared with group 1 (P < .05). Glutamine and SCFA significantly ameliorated the mucosal atrophy. Significant bacterial translocation and catheter infection occurred in group 3. Reduced translocation with SCFA was not significant, but catheter infection was (P < .05). Glutamine significantly reduced translocation and catheter infection.

CONCLUSIONS

There is an association between bacterial translocation and central venous catheter infection. The risk of catheter infection is reduced by supplementing TPN with SCFA or glutamine.

Expression of endothelin 3 by mesenchymal cells of embryonic mouse caecum

BACKGROUND

Mutations in endothelin 3 (EDN3) and endothelin B receptor (EDNRB) genes cause terminal colonic aganglionosis in mice, and mutations in these genes have also been linked to the terminal aganglionosis seen in human Hirschsprung's disease. However, details of EDN3 expression during embryogenesis are lacking, and consequently the cellular mechanism by which EDN3 regulates innervation of the terminal gut is unclear.

AIMS

To localise the expression of EDN3 and EDNRB in the embryonic mouse gut.

METHODS

Expression of EDN3 and EDNRB mRNA was analysed by reverse transcription polymerase chain reaction and in situ hybridisation.

RESULTS

High levels of EDN3 mRNA expression were restricted to mesenchymal cells of the caecum before and after the arrival of neural crest cells. In contrast, EDNRB expression along the gut displayed a time dependent pattern similar to those of the protein tyrosine kinase ret and the neural crest cell marker PGP9.5.

CONCLUSIONS

Mesenchymal cells of the caecum express high levels of EDN3 mRNA during embryogenesis and hence the production of EDN3 at the caecum is likely to act on neural crest cells as a paracrine factor necessary for subsequent innervation of the terminal gut.

Pulmonary neuroendocrine cells in nitrofen-induced diaphragmatic hernia and the effect of prenatal glucocorticoids

The high mortality associated with congenital diaphragmatic hernia (CDH) is due to pulmonary hypoplasia and hypertension, structural and functional abnormalities which can to some extent be ameliorated by prenatal administration of glucocorticoids. In the hypoplastic, hypertensive lungs of neonatal rats in which CDH has been induced by nitrofen, those pulmonary neuroendocrine cells (PNCs) containing calcitonin gene-related peptide (CGRP) increase in number, and it has been suggested that this might be due to inhibition of secretion of the peptide, the consequent decrease in its vasodilatory effects contributing to the hypertension. Whether this increase affects the entire population of PNCs, however, and how these cells are affected by administration of prenatal glucocorticoids, is unknown. As revealed by immunolabelling for protein gene product (PGP) 9.5, a general marker of NCs and expressed per cm2 tissue section, the total PNC population in rats with nitrofen-induced CDH was significantly greater than in controls receiving only olive oil (672 vs 375/cm2, P = 0.03) and was further increased (824 per cm2) in animals treated prenatally with dexamethasone (n = 8 in all groups). The increase in the total PNC population in rats with CDH is similar in magnitude to that described for the CGRP-containing subpopulation. Since the major role of the products of PNCs is now thought to be the regulation of development of pulmonary tissues and their response to injury, it is probable that the expansion of their population in the abnormal lungs associated with CDH is an adaptive response to pulmonary maldevelopment, a response possibly augmented by exogenous corticosteroids.

Abscess after appendicectomy in children: the role of conservative management

BACKGROUND

Intra-abdominal abscess remains a significant cause of morbidity following appendicectomy. In children, little emphasis has been placed on the non-invasive management of this complication using antibiotic therapy alone. This study reviews the experience of a paediatric surgical department in managing abscess arising after appendicectomy.

METHODS

Hospital records of all children undergoing appendicectomy between January 1992 and January 1997 were reviewed retrospectively.

RESULTS

Some 1024 children underwent appendicectomy over a 5-year period. Twenty three patients (2.2 per cent) developed abscesses after appendicectomy. Non-operative management with intravenous or oral antibiotics alone was successful in 21 patients, with complete clinical and radiological resolution of the abscess. Drainage of the septic collection was performed in only two patients: by laparotomy (n=1) and by the transrectal route (n=1).

CONCLUSION

Antibiotic therapy alone is an efficacious and safe first-line treatment modality in children who develop this complication. Drainage of an abscess developing after appendicectomy is rarely necessary in children.

Functional results following the antegrade continence enema procedure

BACKGROUND

Forty children who underwent the antegrade continence enema (ACE) procedure for faecal soiling were studied to determine factors predictive of outcome.

METHODS

There were four patient groups: (1) ambulant with spinal dysraphism (n = 13), (2) wheelchair bound with spinal dysraphism (n = 14), (3) ambulant with miscellaneous disorders (n = 11) and (4) wheelchair bound with miscellaneous disorders (n = 2). Effectiveness of the procedure was assessed using technical evaluation and quality-of-life improvement (QOLI) scores (0-5). Objective assessment included colonic transit time (CTT) and anorectal manometry. Median follow-up was 21 (range 5-37) months.

RESULTS

Some 28 of 40 children achieved continence. The procedure was reversed in four of 40 children. Of the other 36 children with a functioning ACE stoma, all reported improvement in quality of life (mean QOLI score 3.5). There were no significant differences in technical evaluation score, QOLI score, CTT, manometry findings or continence between ambulant groups and the wheelchair-bound group with miscellaneous disorders. QOLI score, anorectal squeeze pressure and continence were significantly poorer in those who were wheelchair bound with spinal dysraphism. Absent squeeze pressure was associated with poor outcome.

CONCLUSION

Wheelchair-bound children with spinal neuropathy have a poorer outcome following the ACE procedure. Although ACE is an effective method of promoting faecal continence, it is essential to determine the aetiology of incontinence and sphincter function before operation.

Effect of dexamethasone on endothelial nitric oxide synthase in experimental congenital diaphragmatic hernia

AIMS

To study the effect of prenatal glucocorticoid treatment on endothelial nitric oxide synthase (eNOS) expression in rats with congenital diaphragmatic hernia (CDH).

METHODS

CDH was induced in fetal rats by the maternal administration of nitrofen on day 9.5 of gestation. Dexamethasone was administered on days 18.5 and 19.5 before delivery of the fetuses on days 20.5 and 21.5. Pulmonary eNOS protein expression was studied by western immunoblotting and immunohistochemistry.

RESULTS

On day 20.5, eNOS expression was significantly reduced in CDH pups compared with normal control rats. Dexamethasone treated CDH pups had eNOS concentrations equivalent to those of normal animals. By day 21.5, however, there was no detectable difference in eNOS expression between the experimental groups.

CONCLUSIONS

eNOS is deficient in near term (day 20.5) CDH rats. Dexamethasone restores eNOS expression in these animals to that seen in normal rat lungs. At term, the precise role of eNOS in the pathophysiology of CDH remains uncertain.

Clinical impact of abnormal gut flora in infants receiving parenteral nutrition

OBJECTIVE

Illness is associated with the carriage of abnormal flora (aerobic Gram-bacilli except E. coli) in the oropharynx and rectum. The aim of this study was to investigate whether carriage of abnormal flora is associated with increased risk of sepsis and septicemia in surgical newborn infants.

METHODS

A 2-year prospective study was carried out on 94 consecutive newborn infants requiring parenteral nutrition (PN) for gastrointestinal abnormalities. Throat and rectal swabs were taken on day 1 of PN and twice weekly. Patients were divided into two groups: abnormal flora (AF; n = 41) and normal flora (NF; n = 53). Sepsis was defined as clinical features of generalized inflammation requiring blood culture. Septicemia was the combination of sepsis and positive blood culture.

RESULTS

Among the infants carrying abnormal flora Pseudomonas and Enterobacter spp. predominated. Duration of PN (AF median 30 days; NF median 9 days), incidence of sepsis (AF 29%; NF 6%), and septicemia (AF 22%; NF 2%) were significantly greater in the group of infants with abnormal flora. Surveillance cultures allow the detection of a subset of infants on PN at high risk of sepsis and septicemia. The degree of gut dysfunction related to the severity of underlying disease determines the duration of PN and the development of abnormal flora. The association between abnormal carriage and increased risk of sepsis and septicemia may be because of the intestinal endotoxin pool known to cause liver impairment and consequent suppression of systemic immunity.

The value of early postoperative oesophagography following repair of oesophageal atresia

The aim of the study was to examine the relationship between anastomotic leaks and the development of symptomatic anastomotic strictures after primary repair of oesophageal atresia (OA) with or without tracheo-oesophageal fistula (TOF) and the prognostic value of the anastomotic appearance on postoperative oesophagography. The records and X-ray films of 49 patients with OA with or without TOF admitted between January 1990 and June 1995 were reviewed retrospectively. Of these, 37 had a primary repair (34 immediate and 3 delayed) and a postoperative contrast swallow was done between day 5 and day 30 (median day 7). Radiological leaks were documented. In addition, the maximum transverse diameters of the upper pouch and anastomotic region and the length of the anastomotic narrow segment were measured; the ratio of upper-pouch diameter to that of the anastomosis was calculated (anastomotic index, AI). The need for dilatation of symptomatic anastomotic strictures and for repeat dilatation as a separate episode were documented. Of the 37 patients, 4 developed an anastomotic leak (11%), 3 radiological and 1 clinical. A symptomatic stricture occurred in 55% of patients. There was no correlation between a leak and later development of a symptomatic stricture, although the small number of patients with leaks precluded definite conclusions. No radiological leak progressed to a clinical leak. There was no correlation between the AI or the length of the anastomotic narrow segment and the need for dilatation, the need for repeat dilatation, or the number of dilatations. In this study, the presence of a leak, the AI, and the length of the narrow segment on early postoperative contrast swallow did not correlate with the later development of a symptomatic stricture. A radiological leak was of no clinical significance. Since major leaks are apparent clinically, an early routine contrast study did not influence management and is not necessary.