Beyond image defined risk factors (IDRFs): a delphi survey highlighting definition of the surgical complexity index (SCI) in neuroblastoma

PURPOSE

Preoperative evaluation of Image Defined Risk Factors (IDRFs) in neuroblastoma (NB) is crucial for determining suitability for upfront resection or tumor biopsy. IDRFs do not all carry the same weighting in predicting tumor complexity and surgical risk. In this study we aimed to assess and categorize a surgical complexity (Surgical Complexity Index, SCI) in NB resection.

METHODS

A panel of 15 surgeons was involved in an electronic Delphi consensus survey to identify and score a set of shared items predictive and/or indicative of surgical complexity, including the number of preoperative IDRFs. A shared agreement included the achievement of at least 75% consensus focused on a single or two close risk categories.

RESULTS

After 3 Delphi rounds, agreement was established on 25/27 items (92.6%). A severity score was established for each item ranging from 0 to 3 with an overall SCI range varying from a minimum score of zero to a maximum score of 29 points for any given patient.

CONCLUSIONS

A consensus on a SCI to stratify the risks related to neuroblastoma tumor resection was established by the panel experts. This index will now be deployed to critically assign a better severity score to IDRFs involved in NB surgery.

Impact of neoadjuvant chemotherapy on thrombus viability in patients with Wilms tumour and caval extension: systematic review with meta-analysis

BACKGROUND

Inferior vena cava (IVC) tumour thrombus in children with Wilms tumour is typically managed with neoadjuvant chemotherapy with the intention of achieving thrombus regression in order to minimize the risks associated with complex vascular surgery.

METHODS

A systematic review of Medline and Embase databases was undertaken to identify all eligible studies with reference to thrombus viability in Wilms tumour index cases with caval/cardiac extension. A meta-analysis of proportions was utilized for pooled thrombus viability data across studies. Logistic regression was used to analyse the relationship between thrombus viability and duration of chemotherapy.

RESULTS

Thirty-five eligible observational studies and case reports met inclusion criteria describing a total of 236 patients with thrombus viability data. The pooled proportion of patients with viable tumour thrombus after neoadjuvant chemotherapy was 0.53 (0.43-0.63). Logistic regression analysis of 54 patients receiving either a standard (4-6 weeks) or extended (more than 6 weeks) course of neoadjuvant chemotherapy resulted in an odds ratio of 3.14 (95 per cent c.i. 0.97 to 10.16), P = 0.056, with extended course therapy trending towards viable tumour thrombus.

CONCLUSION

Preoperative chemotherapy is successful in achieving non-viability of caval and cardiac thrombi in around 50 per cent of children, without added benefit from extended cycles of neoadjuvant chemotherapy. Risks versus benefits of extirpative vascular surgery must be considered, therefore, for these high-risk patients.

Fetal surgery

Fetal medicine is a super-specialty enterprise and a technology-driven field. The growth and interest in fetal surgery can be largely attributed to advances in fetal imaging and bespoke instruments for in utero intervention. Previously fatal fetal conditions are now being treated using open surgery, minimally invasive procedures, and percutaneous fetal technologies. Several fetal conditions, including myelomeningocele and twin-to-twin transfusion syndrome, have been tested rigorously in RCTs. However, as the specialty of fetal surgery grows, a robust evidence base with long-term follow-up is obligatory for every procedure. This article offers an overview of fetal surgery and antenatal intervention. As more cutting edge therapies come into clinical practice, growing public opinion and medical ethics will play a significant role in the future of this multidisciplinary specialty.

Posterior urethral valves masquerading as neuropathic bladder following sacrococcygeal teratoma resection

Neuropathic bladder may be a co-associated morbidity in newborn babies following resection of a sacrococcygeal teratoma. We report a case of a male newborn showing features of incomplete urinary voiding requiring intermittent catheterisation after operation for bladder emptying. Videourodynamic assessment excluded neuropathic bladder and posterior urethral valves were demonstrated on micturating cystography. Urology outcomes have been excellent following curative valve ablation. This report highlights the crucial importance of being aware of the rare coexistence of lower urinary tract pathology in male babies with sacrococcygeal teratoma. Routine urodynamic assessment should be considered in all children following sacrococcygeal teratoma resection.

Ovarian tumors in children: how common are lesion recurrence and metachronous disease? A UK CCLG Surgeons Cancer Group nationwide study

BACKGROUND

Ovarian tumors in children are rare, mature teratoma being the most common histological entity. Robust guidelines to aid patient follow-up after resection are distinctly lacking. Although mature teratoma has a very good prognosis following complete resection, small studies have reported the occurrence of metachronous disease and recurrence to a variable degree (2.5-23% of patients). Nevertheless, there are surgeons who recommend no follow-up is required for these children after primary tumor resection. We investigated the incidence of (i) recurrence and (ii) metachronous disease in pediatric patients following ovarian tumor resection.

METHODS

Retrospective multicenter study amongst UK pediatric surgical oncology centers. Females <16 years with diagnosis of ovarian tumor from 2006 to 2016 were included. Functional/neonatal ovarian cysts were excluded.

RESULTS

Three hundred ten patients with ovarian tumors treated at 12 surgical oncology centers were identified. Mean age at surgery was 11 years [IQR 8-14]. Most common diagnosis were mature teratoma (57%, 177 cases), immature teratoma (10.9%, 34 cases) and serous cystadenoma (7.7%, 24 cases). 8.1% (25 cases) of all females were identified with tumor recurrence/ metachronous disease. 5.1% (9 cases) of patients with mature teratoma had recurrent/ metachronous disease. Most of these patients were diagnosed at routine clinic follow-up.

CONCLUSION

Our study clearly shows that ovarian tumor recurrence(s) and metachronous disease occur, even in "benign" ovarian tumors. We recommend female pediatric patients should have robust follow-up care plans after primary diagnosis and resection of ovarian tumor(s).

LEVEL OF EVIDENCE STATEMENT

This is a level II evidence study. It is a retrospective multicentre collaborative study which summarizes data from a national cohort of children.

Efficacy of antireflux surgery in children with or without neurological impairment: a systematic review

BACKGROUND

Antireflux surgery is commonly performed in children, yet evidence for its efficacy is limited. The aim of this review was to determine the effect of antireflux surgery with regard to objective measures of quality of life (QoL) and value of upper gastrointestinal investigations in neurologically normal (NN) and neurologically impaired (NI) children.

METHODS

A systematic review was conducted of articles reporting children undergoing antireflux surgery in whom preoperative and postoperative objective testing was performed. Primarily, Embase, CINAHL, MEDLINE and PubMed were searched from inception to April 2019. Methodological Index for Non-randomized Studies (MINORS) criteria were used to assess article quality.

RESULTS

Of 789 articles, 14 met the eligibility criteria, 12 prospective observational and 2 retrospective studies. The median MINORS score was 59·4 (i.q.r. 39 to 62·5) per cent. Seven studies reported assessment of validated QoL measures before and after antireflux surgery in 148 children. Follow-up ranged from 1 to 180 months. All studies confirmed significant improvements in QoL measures among NN and NI children at all follow-up points. Eleven studies reported on preoperative and postoperative investigations in between 416 and 440 children children. Follow-up ranged from 0·5 to 180 months. Nine studies confirmed improvements in gastro-oesophageal reflux using 24-h oesophageal pH monitoring with or without manometry, but conflicting results were identified for four studies reporting gastric emptying. No studies reported fluoroscopy or endoscopy adequately.

CONCLUSION

Based on the results of studies of low-to-moderate quality, antireflux surgery improved QoL and reduced oesophageal acid exposure in NN and NI children in the short and medium term. Although antireflux surgery is a common elective operation, the lack of rigorous preoperative and postoperative evaluation(s) in the majority of patient-reported studies is striking.

Aortopexy for the management of paediatric tracheomalacia - the Alder Hey experience

BACKGROUND

Whilst aortopexy is an accepted and established procedure, there remains considerable heterogeneity within the literature, with inconsistencies in both the approach taken and the technique employed. Furthermore, limited data exist on both patient selection and long-term outcomes. This study aimed to report the experience of managing severe tracheomalacia by way of aortopexy in a large UK paediatric centre.

METHOD

A retrospective case note review was conducted. Mean follow up was five years.

RESULTS

Twenty-five patients underwent aortopexy for severe tracheomalacia caused by external vascular compression. Acute life-threatening events precipitated investigation in 72 per cent of cases. Twenty-one patients initially presented to ENT services for investigation, which comprised upper airway endoscopy and imaging with computed tomography angiography. Post-operatively, the majority of patients demonstrated complete resolution of symptoms and were discharged from all associated services. Only four patients required a tracheostomy.

CONCLUSION

Aortopexy offers an effective method of treating severe tracheomalacia due to vascular compression.

The challenges of surgical research in children

Trials in children needed

Transitional care and paediatric surgery

Merits urgent attention

Outcomes following prosthetic patch repair in newborns with congenital diaphragmatic hernia

Background

The anatomical defect in congenital diaphragmatic hernia (CDH) can usually be closed primarily but prosthetic patch repair may be required in newborns with a deficient diaphragm. High rates of patch failure and hernia recurrence (up to 50 per cent) have been reported. This study evaluated contemporary outcomes following patch repair of CDH at a UK paediatric surgical centre.

Methods

Medical records of newborns undergoing surgery for CDH between 1 February 1990 and 1 November 2010, and attending a multidisciplinary follow-up clinic, were examined. Operative details and patch utilization are reported.

Results

Of 118 newborns with CDH, 37 required a patch to the diaphragmatic defect. Gore-Tex® patches were used in 35 and biological Surgisis® patches in two. Eight babies additionally required an abdominal wall patch. Seven infants had an abdominal patch alone with primary diaphragm repair. A total of 102 infants (86·4 per cent) survived after surgery. Two early recurrences were both related to the use of biological patches, leading to revisional surgery with Gore-Tex® patch reconstruction. Diaphragmatic patch use was associated with a greater requirement for intensive cardiovascular and respiratory support, although there was no significant difference in mortality between patch versus primary diaphragm repair. The mortality rate was significantly higher among infants requiring abdominal wall patching (with or without a diaphragmatic patch): 40 per cent (6 of 15) versus 9·7 per cent (10 of 103) (P = 0·006). Postoperative survival rates for infants with a diaphragmatic patch alone, abdominal wall patch alone, and both abdominal and diaphragmatic patches were 86 per cent (25 of 29), 57 per cent (4 of 7) and 63 per cent (5 of 8) respectively.

Conclusion

Prosthetic diaphragmatic hernia repair at this centre has a good outcome and low rate of recurrence (5 per cent). The recognition of an inadequate abdominal domain prenatally may additionally prove to be a useful marker for predicting increased mortality in newborns with CDH.

Use of a tissue expander as a radio-protective spacer with a latissimus dorsi flap in the management of a peripheral primitive neuroectodermal tumour (pPNET)

Peripheral primitive neuroectodermal tumours (pPNET) are aggressive neoplasms that require radical surgical resection with adjuvant chemotherapy and radiotherapy. A pPNET of the posterior chest wall was resected with wide soft tissue margins in a 14 year old male. Following tumour excision a spacer device was positioned in the retroperitoneum adjacent to the ipsilateral left kidney displacing it from the planned radiotherapy field. A pedicled latissimus dorsi myocutaneous flap was used to achieve robust soft tissue cover. Ultrasound demonstrated anteromedial displacement of the left kidney with no hydronephrosis and renal function remained normal during subsequent radiotherapy. This report highlights the usefulness of a tissue expander in providing protection for vital structures during radiotherapy.

Randomized clinical trial of glutamine-supplemented versus standard parenteral nutrition in infants with surgical gastrointestinal disease

BACKGROUND

Addition of glutamine to parenteral nutrition in surgical infants remains controversial. The aim of this trial was to determine whether glutamine supplementation of parenteral nutrition in infants requiring surgery would reduce the time to full enteral feeding and/or decrease the incidence of sepsis and septicaemia.

METHODS

A prospective double-blind multicentre randomized clinical trial was performed in surgical infants less than 3 months old who required parenteral nutrition. Patients were allocated to treatment or control groups by means of minimization. Infants received either 0·6 g per kg per day alanyl-glutamine (treatment group) or isonitrogenous isocaloric parenteral nutrition (control group) until full enteral feeding was achieved. Primary outcomes were time to full enteral feeding and incidence of sepsis. Cox regression analysis was used to compare time to full enteral feeding, and to calculate risk of sepsis/septicaemia.

RESULTS

A total of 174 patients were randomized, of whom 164 completed the trial and were analysed (82 in each group). There was no difference in time to full enteral feeding or time to first enteral feeding between groups, and supplementation with glutamine had no effect on the overall incidence of sepsis or septicaemia. However, during total parenteral nutrition (before the first enteral feed), glutamine administration was associated with a significantly decreased risk of developing sepsis (hazard ratio 0·33, 95 per cent confidence interval 0·15 to 0·72; P = 0·005).

CONCLUSION

Glutamine supplementation during parenteral nutrition did not reduce the incidence of sepsis in surgical infants with gastrointestinal disease.

REGISTRATION NUMBER

ISRCTN83168963 (http://www.controlled-trials.com).

Value of liver herniation in prediction of outcome in fetal congenital diaphragmatic hernia: a systematic review and meta-analysis

OBJECTIVES

Intrathoracic liver herniation (ILH) is being used to estimate prognosis and hence guide antenatal interventions in fetal congenital diaphragmatic hernia (CDH). However, the literature regarding its utility in this role is conflicting. This review systematically examines the currently available evidence of ILH use in fetal CDH.

METHODS

MEDLINE and EMBASE databases were searched for the terms ((congenital diaphragmatic hernia) OR CDH) AND liver. Inclusion criteria were human case series of fetuses diagnosed with CDH using either ultrasound or magnetic resonance imaging. Included studies were required to have reported the antenatal liver position and the outcome (survival or not). Case reports, reviews and eventration series were excluded. Studies reporting similar cases from the same center over an overlapping time period were considered duplicates; only the larger of the studies were therefore included. Absolute totals were extracted and sums calculated. Fisher's exact test (FET) was used to compare survival rates in different groups.

RESULTS

The original search retrieved 338 studies. Applying inclusion/exclusion criteria and removing duplicates left 21 case series in 20 studies. Retrieved studies differed in the definitions of liver herniation, survival and treatment modality. In total, there were 407 fetuses in the liver-up (herniated) and 303 in the liver-down (not herniated) groups. Survival rates were 45.4% and 73.9%, respectively. The difference was statistically significant (FET = 56.4, P < 0.005). Sensitivity analysis for cases that had only conventional postnatal treatment was still significant (FET = 52.8, P < 0.005).

CONCLUSIONS

Liver herniation is associated with poorer prognosis in fetal CDH. Grading liver herniation or using it as part of a panel of markers may enhance the value of liver herniation as a prognostic test in fetal CDH.

Phaeochromocytoma in children

Phaeochromocytoma is a rare clinical entity in children. Contrary to traditional teaching, which suggested that 10% of phaeochromocytomas are "familial", a germline mutation has been identified in up to 59% (27/48) of apparently sporadic phaeochromocytomas presenting at 18 years or younger and in 70% of those presenting before 10 years of age. The inherited predisposition may be attributable to a germline mutation in the Von Hippel-Lindau gene, the genes encoding the subunits B and D of succinate dehydrogenase, the RET proto-oncogene predisposing to multiple endocrine neoplasia type 2, or the neurofibromatosis type 1 gene. Of these, the Von Hippel-Lindau gene is the most commonly mutated gene in children presenting with a phaeochromocytoma. Genetic counselling is recommended before gene testing and investigation of the wider family. This review provides guidance on the aetiology, investigation, management, histopathology, genetics and follow-up of children with a phaeochromocytoma.

Infections in gastroschisis: organisms and factors

This study aimed to define the incidence, causative organisms and predisposing factors leading to infection related morbidity in newborns with gastroschisis. All gastroschisis patients admitted over the 5-year period (1999-2004) were retrospectively reviewed. Surveillance samples, wound, blood, urine and fecal cultures were analyzed. Duration of total parenteral nutrition, antibiotic therapy, feeding regimes and demographic data were also analyzed. Multiple logistic regression was employed using the SPSS system and p < 0.05 was considered as significant. Seventy-two neonates were identified with 53% having abnormal gut carriage mostly due to Enterobacter and Klebsiella. Wound infection occurred in 20% of cases. Abnormal gut carriage predisposed to the development of wound infection. Line sepsis occurred in 21% of neonates. Endogenous coagulase negative Staphylococcus caused 74% of septic episodes. There was no correlation between abnormal gut carriage and the development of line sepsis. Overall survival was 96%. The cause of infections in gastroschisis patients appears to be multifactorial. A multidisciplinary team can play an important role in reducing the incidence of infections. Strict aseptic protocols and auditing practice can be the invaluable tools in decreasing morbidity rates.

Infantile myofibromatosis of the craniovertebral junction

Infantile myofibromatosis (IM) is a rare pathological entity characterized by solitary or multiple nodular skin, soft tissues or bony lesions. Craniovertebral (CV) junction lesions are rare. We report the successful management of a solitary IM involving the posterior elements of the CV junction in a 6-month-old child.

Oesophageal atresia with cleft lip and palate: a marker for associated lethal anomalies?

An adverse association between oesophageal atresia (OA) and cleft lip-palate (3% incidence) has been reported. The present study analyses outcomes of this rare association at a UK paediatric surgical centre. Hospital charts of newborns diagnosed with OA were reviewed. Demographics, associated anomalies and prognostic classification (after Spitz 1994) were recorded. Mortality rates and causes of death were examined in OA babies with cleft lip-palate. Of 152 patients treated for OA, five babies (3%) had cleft lip-palate. All of these newborns had common variant OA-TEF and were Spitz group II category. Deaths occurred in 3 of 5 patients (60%) in the OA-cleft group compared to only 8 of 147 patients (5%) without clefts (p < 0.005; Fisher's exact test). OA-cleft non-survivors succumbed to tetralogy of Fallot (n = 2) and trisomy 18 (n = 1; treatment withdrawn). Both survivors with cleft lip-palate had features of the VACTERL sequence: one baby also had Goldenhaar syndrome, the other aortic coarctation. These children now attend mainstream school. Although high-quality survival is possible in OA with cleft lip-palate, this rare phenotype is associated with a substantially decreased survival. Rather than causing death directly, the combination of OA and cleft lip-palate appears to be a marker for further lethal anomalies.

How useful is the lung-to-head ratio in predicting outcome in the fetus with congenital diaphragmatic hernia? A systematic review and meta-analysis

OBJECTIVE

Fetal surgery to improve lung growth comprises tracheal occlusion in selected 'high-risk' fetuses with congenital diaphragmatic hernia (CDH). Sonographically measured fetal lung-to-head ratio (LHR) is utilized to recruit candidates for fetal surgery. This study provides a meta-analysis of the evidence regarding the prognostic use of lung-to-head ratio measurements in fetal CDH.

METHODS

MEDLINE, SCOPUS and ISI PROCEEDINGS databases were searched for MeSH terms: lung, head, hernia and ratio. References in retrieved studies were also searched. Studies were categorized as follows: Phase I studies measured normal fetal LHR; Phase II studies compared fetal LHR in CDH survivors and non-survivors (if LHR informed therapy decisions or LHR was not measured during the window for intervention (< 32 weeks' gestation), studies were excluded); Phase III studies used LHR to guide selection for fetal surgery (non-randomized trials were excluded); Phase IV studies measured CDH survival before and after LHR application in clinical practice.

RESULTS

The one Phase I study showed that LHR varied substantially with gestation and technique. No complete studies met the selection criteria for Phase II: meta-analysis of subgroups revealed similar LHR in CDH survivors and non-survivors. A single Phase III study revealed no benefit for LHR-directed fetal surgery. No Phase IV studies were identified.

CONCLUSION

The prognostic use of LHR in fetal CDH entered clinical practice prior to publication of robust normal data and is not supported by current evidence. Application of a structured approach to any 'new' prognostic test could improve its validity and clinical application.

Novel 'phage display antibodies identify distinct heparan sulfate domains in developing mammalian lung

Heparan sulfate proteoglycans (HSPGs) are essential to respiratory morphogenesis in species as diverse as Drosophila and mice; they play a role in the regulation of numerous HS-binding growth factors, e.g. fibroblast growth factors. Moreover, an HS analogue, heparin, modulates lung growth in vitro. However, it has been difficult to assess the roles of specific HS structures in lung development due to technical barriers to their spatial localisation. Lungs from Sprague-Dawley rats were harvested between E15.5 and E19.5 and immediately fixed in 4 % (w/v) paraformaldehyde (in 0.1 M phosphate-buffered saline (PBS), pH 7.4). Lungs were washed in PBS, cryoprotected with 20% (w/v) sucrose (in PBS), gelatin embedded [7.5% (w/v) gelatin, 15% (w/v) sucrose in PBS], before being covered in Cryo-M-Bed (Bright, Huntingdon, UK) and snap frozen at -40 degrees C. Cryosections were cut at 8 microm and stained with the HSPG core protein specific antibody 3G10 and a HS 'phage display antibody, EW4G2V. 3G10 and EW4G2V immunohistochemistry highlighted the presence of specific HS structures in lungs at all gestational ages examined. 3G10 strongly labelled airway basement membranes and the surrounding mesenchyme and showed weak staining of airway epithelial cells. EW4G2V, however, was far more selective, labelling the airway basement membranes only. Mesenchymal and epithelial cells did not appear to possess the HS epitope recognised by EW4G2V at these gestational ages. Novel 'phage display antibodies allow the spatial distribution of tissue HS to be analysed, and demonstrate in situ that distinct cellular compartments of a tissue possess different HS structures, possibly on the same proteoglycan core protein. These probes offer a new opportunity to determine the role of HS in the pathogenesis of congenital defects such as congenital diaphragmatic hernia (CDH), where lung development is aberrant, and the resulting pulmonary hypoplasia and hypertension are a primary cause of mortality.

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.

Oesophageal atresia and tracheo-oesophageal fistula

Oesophageal atresia-tracheo-oesophageal fistula has featured in paediatric surgery since its beginnings. The first successful primary repair was in 1941. With overall survival now exceeding 90% in dedicated centres, the emphasis has changed to reducing morbidity and achieving improvements in the quality of life. An overview of current and emerging strategies in managing patients with this condition is presented. Advances in developmental biology and molecular genetics reflecting improved understanding of the pathogenesis are highlighted.

Morphological and molecular assessment of apoptotic mechanisms in peripheral neuroblastic tumours

Multiple defects in apoptotic pathways have been described in peripheral neuroblastic tumours (NTs). Mitosis–karyorrhexis index (MKI) is a reliable morphological marker identifying favourable and unfavourable NTs. The extent to which apoptotic processes contribute to determine the clinical significance of MKI is still undefined. Apoptosis was investigated in a series of 110 peripheral NTs by comparing MKI to immunohistochemical and molecular apoptotic features. High MKI was found in 55 out of 110 NTs (50%) and was associated with advanced stage (P=0.007), neuroblastoma (NB) histological category (P=0.024), MYCN amplification (P<0.001), and poor outcome (P=0.011). Overall survival probability was 45% in patients with high MKI compared to 73% in patients with low MKI. In the same 110 NTs, the expression of Bcl-2, Bcl-X_L, Bax and Mcl-1 was studied by immunohistochemistry, but no significant associations were found with clinicohistological features. Microarray analysis of apoptotic genes was performed in 40 out of 110 representative tumours. No significant association was found between the expression of apoptotic genes and MKI or clinicohistological features. Proliferative activity was assessed in 60 out of 110 representative tumours using Ki67 immunostaining, but no significant correlations with MKI or clinicobiological features were found. In NTs, the combination of apoptosis and proliferation as expressed by MKI is a significant prognostic parameter, although neither of them is per se indicative of the clinicobiological behaviour and outcome.

Peristalsis of airway smooth muscle is developmentally regulated and uncoupled from hypoplastic lung growth

Prenatal airway smooth muscle (ASM) peristalsis appears coupled to lung growth. Moreover, ASM progenitors produce fibroblast growth factor-10 (FGF-10) for lung morphogenesis. Congenital diaphragmatic hernia (CDH) is associated with lung hypoplasia, FGF-10 deficiency, and postnatal ASM dysfunction. We hypothesized ASM dysfunction emerges in tandem with, and may contribute toward, the primordial lung hypoplasia that precedes experimental CDH. Spatial origin and frequency of ASM peristaltic waves were measured in normal and hypoplastic rat lungs cultured from day 13.5 of gestation (lung hypoplasia was generated by nitrofen dosing of pregnant dams). Longitudinal lung growth was assayed by bud counts and tracing photomicrographs of cultures. Coupling of lung growth and peristalsis was tested by stimulation studies using serum, FGF-10, or nicotine and inhibition studies with nifedipine or U0126 (MEK1/2 inhibitor). In normal lung, ASM peristalsis is developmentally regulated: proximal ASM becomes quiescent (while retaining capacity for cholinergic-stimulated peristalsis). However, in hypoplastic lung, spontaneous proximal ASM activity persists. FGF-10 corrects this aberrant ASM activity in tandem with improved growth. Stimulation and inhibition studies showed that, unlike normal lung, changes in growth or peristalsis are not consistently accompanied by parallel modulation of the other. ASM peristalsis undergoes FGF-10-regulated spatiotemporal development coupled to lung growth: this process is disrupted early in lung hypoplasia. ASM dysfunction emerges in tandem with and may therefore contribute toward lung hypoplasia in CDH.

Abnormal lung development precedes oligohydramnios in a transgenic murine model of renal dysgenesis

PURPOSE

Renal development regulates prenatal lung growth by maintaining fetal urine output and liquor volume. However, shared signaling pathways underpinning renal and lung morphogenesis indicate that lung hypoplasia in the presence of renal dysgenesis may not result from oligohydramnios alone. We used a transgenic model of renal agenesis/anuria to test whether lung hypoplasia precedes any possible influence of oligohydramnios.

MATERIALS AND METHODS

E12 lung primordia from normal and gamma1III4 deficient murine embryos (fetal anuria and renal agenesis-dysgenesis) were cultured for 72 hours. Morphological lung development was measured at 24, 48 and 78 hours by bud counting and tracings of lung epithelial contour using image analysis software and photomicrographs. Genotyping was performed by a separate blinded investigator.

RESULTS

E12 homozygous mutant lungs branched but had significant decreases in bud count, epithelial area and perimeter compared to heterozygous or WT controls. These changes presented prior to oligohydramnios and persisted in isolation from the developing renal tract throughout the 72-hour culture period.

CONCLUSIONS

Lethal lung hypoplasia seen at term in this model is present from the earliest stages of development, persists in vitro and, therefore, it is not consequent on renal dysfunction. These data implies that 1) fetal interventions for severe prenatal uropathies may have variable success for protecting future lung function and 2) patients with fetal uropathies may warrant greater scrutiny of prenatal lung growth and long-term postnatal lung function.

Sex and congenital diaphragmatic hernia

BACKGROUND AND PURPOSE

Human studies note sex reversal syndromes and sex difference(s) in the incidence of congenital diaphragmatic hernia (CDH). Epidemiology surveys record a higher incidence of CDH in females, whilst other reports cite a higher frequency in males. Nitrofen, a teratogen, produces experimental CDH. This agent is speculated to interfere with retinoid acid-steroid signalling pathways and may also be linked with sexual differentiation. This study was designed therefore to test the hypothesis that nitrofen may influence sexual phenotype and frequency of CDH.

METHODS

Time mated Sprague Dawley rats were dosed with nitrofen at day 9.5 to generate predominantly left sided CDH. Fetuses were delivered by caesarean section on days 20 or 21 of gestation (term=day 22). External genitalia were examined to define external genital phenotype. The abdominal cavity was opened and the genito-urinary system carefully examined. The internal genital organs were assigned a phenotype and findings correlated with external appearances. The diaphragm of each fetus was studied for the absence or presence of CDH and the laterality of defect recorded. Controls (non nitrofen fed) were used for all comparative analysis.

RESULTS

Control (n=600) and nitrofen exposed offspring (n=504) had equal frequencies of males and females. CDH occurred with similar incidence in male and female nitrofen treated pups. In all nitrofen exposed fetuses and normal controls, internal and external genitalia concorded without evidence of significant genital tract malformations or intersex states.

CONCLUSIONS

Prenatal nitrofen exposure is not associated with significant gender differences (or prenatal loss) in the risk of CDH. Genital tract malformations do not appear to accompany CDH in the nitrofen model.

Recent advances in congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a common birth defect which continues to challenge paediatric surgeons and intensivists. Affecting approximately 1:2500 births, a baby with CDH is born every 24-36 hours in the UK.

Emergent embolisation to control severe haematuria in Wilms' tumour

Wilms' tumour commonly presents with an abdominal mass and gross haematuria. Here, we present the novel application of paediatric renal arterial embolisation to control life-threatening haematuria in Wilms' tumour.

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.

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.

Outcome of hypospadias fistula repair

Objectives To examine the long-term results of hypospadias fistula repair, the factors involved in recurrence and the outcome in cases where this has occurred. Patients and methods The study comprised 113 children undergoing urethrocutaneous fistula repair between 1984 and 1996. Most of the fistulae were closed in two to three layers, with or without a transpositional skin flap. Tunica vaginalis or a scrotal dartos flap was used in patients with inadequate vascularized tissue adjacent to the fistula. Success rates were calculated for each attempt at fistula repair until the patient was cured. Results The median (range) age at primary fistula repair was 40 (18-169) months and the median follow-up after the most recent repair 7.5 (2.3-17) years. The overall success rate of primary fistula repair was 71%. Fistulae which were >2 mm (11 of 21, 52%) were more likely to recur than were those < or = 2 mm (22 of 92, 24%). Recurrence did not relate to the initial form of hypospadias repair, to the means of skin closure nor, with the exception of multiple lesions, to the location of the fistula. The success rates of subsequent repairs were 70% at the second and 50% at the third, fourth and fifth repairs. One child was cured at the sixth attempt. The use of tunica vaginalis or scrotal dartos as a 'waterproofing' layer was limited to the third or subsequent repairs and was successful in five of six cases. Conclusion A simple layered closure with or with no transpositional skin flap is effective in 71% of repairs. For recurrent fistulae, tissues from an unscarred area (tunica vaginalis or scrotal dartos layer) should be used to cover the fistula.

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.

Use of the gonadal vein in children with difficult central venous access: a novel technique

In children who require multiple central venous catheterization, the commonly used veins can become thrombosed making central venous access a challenging problem. The authors report on a patient with a rare metabolic disorder who had extensive thrombosis of the superior vena cava and iliofemoral veins, in whom the right ovarian vein was cannulated using a retroperitoneal approach for the placement of a SILASTIC((R)) (Dow Corning, Midland, MI) catheter with an implantable port. This is a useful and reliable technique in children who have difficult venous access.

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.

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.

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.

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.