Design of a virtual data shelf to effectively explore a large database of 3D medical surface models in VR.

PURPOSE: Medical researchers deal with a large amount of patient data to improve future treatment decisions and come up with new hypotheses. To facilitate working with a large database containing many patients and parameters, we propose a virtual data shelf, displaying the 3D anatomical surface models in an immersive VR environment. METHODS: Thereby, different functionalities such as sorting, filtering and finding similar cases are included. To provide an appropriate layout and arrangement of 3D models that optimally supports working with the database, three layouts (flat, curved and spherical) and two distances are evaluated. A broad audience study with 61 participants was conducted to compare the different layouts based on their ease of interaction, to get an overview and to explore single cases. Medical experts additionally evaluated medical use cases. RESULTS: The study revealed that the flat layout with small distance is significantly faster in providing an overview. Applying the virtual data shelf to the medical use case intracranial aneurysms, qualitative expert feedback with two neuroradiologists and two neurosurgeons was gathered. Most of the surgeons preferred the curved and spherical layouts. CONCLUSION: Our tool combines benefits of two data management metaphors, resulting in an efficient way to work with a large database of 3D models in VR. The evaluation gives insight into benefits of layouts as well as possible use cases in medical research.

Optimized signal deduction procedure for the MIEZE spectroscopy technique.

A method is reported to determine the phase and amplitude of sinusoidally modulated event rates, binned into four bins per oscillation, based on data generated at the resonant neutron spin-echo spectrometer RESEDA at FRM-II. The presented algorithm relies on a reconstruction of the unknown parameters. It omits a calculation-intensive fitting procedure and avoids contrast reduction due to averaging effects. It allows the current data acquisition bottleneck at RESEDA to be relaxed by a factor of four and thus increases the potential time resolution of the detector by the same factor. The approach is explained in detail and compared with the established fitting procedures of time series having four and 16 time bins per oscillation. In addition the empirical estimates of the errors of the three methods are presented and compared with each other. The reconstruction is shown to be unbiased, asymptotic and efficient for estimating the phase. Reconstructing the contrast increases the error bars by roughly 10% as compared with fitting 16 time-binned oscillations. Finally, the paper gives heuristic, analytical equations to estimate the error for phase and contrast as a function of their initial values and counting statistics.

Cost-effectiveness of gastrostomy placement for children with neurodevelopmental disability.

INTRODUCTION: Malnutrition and growth deficiency are common in neurologically impaired children. Gastrostomy placement has been shown to result in significant catch-up growth, improved health of the child and reduction in family stress; its cost-effectiveness has not been investigated. AIMS: Costs related to gastrostomy placement are estimated here from a prospective controlled study of children referred to a tertiary paediatric centre in the UK. METHODS: Costs of inpatient stay, medication, tests, general practitioner consultations, community healthcare, equipment, and parents' indirect costs were estimated at baseline and follow-up. Costs of the different types of gastrostomy surgery are given. RESULTS: Results for both time periods were available for 54 of the 76 children recruited to the study. Five-day food diaries were kept at baseline and follow-up. Costs of food increased slightly but not significantly post surgery from pound sterling 33 to pound sterling 40 (Euro 44 to Euro 54, US$65 to US$78) per week. Variation in cost between cases was considerable but the mean net cost difference of pound sterling 20.80 (CI - pound sterling 43.79 to pound sterling 85.35) (Euro 28 (CI Euro-59 to Euro 115), US$41 (CI US$-86 to US$167)) per week per child including for food and surgery, was also not significant. Community service costs were significantly lower post surgery. Few parents reported personal costs at either time point, although many had reduced or stopped paid work to care for the child. CONCLUSION: As gastrostomy placement for these children resulted in significant clinical benefit at no significant extra cost, it is concluded that the procedure is cost-effective.

Successful resection of a congenital superior mesenteric arteriovenous malformation.

A 15-month-old male presented with severe gastrointestinal bleeding and heart failure. Imaging revealed a superior mesenteric artery arteriovenous malformation, associated with a congenital portosystemic shunt. The heart failure was cured by resection of the arteriovenous malformation.

Congenital alveolar capillary dysplasia and associated gastrointestinal anomalies.

Congenital alveolar capillary dysplasia is a rare cause of irreversible pulmonary hypertension with 100% mortality. We present three cases of congenital alveolar capillary dysplasia with associated gastrointestinal abnormalities. Three full-term neonates presented with pulmonary hypertension needing ventilatory support by oscillation. Of the three, two neonates subsequently needed extracorporeal membrane oxygenation. Abdominal distension associated with bilious aspirates was the gastrointestinal manifestation. One child had duodenal atresia and anorectal anomaly, one with intestinal malrotation and the other with a rare combination of intestinal malrotaion and total colonic Hirschsprung's disease. All three infants succumbed to pulmonary hypertension at mean age 34 days. The etiopathogenesis and pathology of this condition are discussed with a comprehensive review of the literature.

Medical, surgical, and health outcomes of gastrostomy feeding.

A prospective controlled study with repeated measures before and after surgery examined the medical, surgical, and health outcomes of gastrostomy for children with disabilities at a tertiary paediatric referral centre in the North Thames area, UK. Anthropometric measures included weight, mid-upper-arm and head circumference. Five-day prospective food diaries were completed and data on physical health and surgical outcomes recorded. Seventy-six children participated and underwent gastrostomy (44 males, 32 females; median age 3 y 4 mo, range 4 mo-17 y 5 mo), and 35/76 required an anti-reflux procedure. Categories of disability were: cerebral palsy (32/76), syndrome of chromosomal or other genetic origin (25/76), slowly progressive degenerative disease (11/76), and unconfirmed diagnosis (8/76). Most children had gross motor difficulties (99%) and were non-ambulant (83%). Oromotor problems were identified in 78% of children, 69% aspirated, and 65% were fed nasogastrically before surgery. The mean weight before surgery was -2.84 standard deviation score (SDS; SD 2.21, range -9.8 to 3.4). Two-thirds of children achieved catch-up growth postoperatively: weight-for-age (mean difference 0.51 SDS, 95% CI 0.23-0.79, p=0.001) and mid-upper arm circumference (mean difference 1.12 cm, 95% confidence interval 0.50-1.75, p=0.001). Health gains included a reduction in drooling, secretions, vomiting, and constipation. Major surgical complications were found in 13/74 children. The study provides evidence that catch-up growth and health gains are possible following gastrostomy.

Laparoscopic surgery in children is associated with an intraoperative hypermetabolic response.

BACKGROUND: Laparoscopic surgery is thought to be associated with a reduced metabolic response compared to open surgery. Oxygen consumption (VO2) and energy metabolism during laparoscopic surgery have not been characterized in children. METHODS: We measured respiratory gas exchange intraoperatively in children undergoing 19 open and 20 laparoscopic procedures. Premature infants and patients with metabolic, renal, and cardiac abnormalities were excluded. Anesthesia was standardized. Unheated carbon dioxide was used for insufflation. VO2 was measured by indirect calorimetry. Core temperature was measured using an esophageal temperature probe. RESULTS: We found a steady increase in VO2 during laparoscopy. The increase in VO2 was more marked in younger children and was associated with a significant rise in core temperature. Open surgery was not associated with significant changes in core temperature or VO2. CONCLUSIONS: Laparoscopy in children is associated with an intraoperative hypermetabolic response characterized by increased oxygen consumption and core temperature. These changes are more marked in younger children.

Ex vivo liver surgery for extraadrenal pheochromocytoma.

A case of a 15-year-old girl with a malignant extraadrenal pheochromocytoma situated between the inferior vena cava and the portal triad is described. Using ex vivo technique, the tumour was successfully resected on the bench, as a previous attempt to remove the tumour in situ had been abandoned. The surgical aspects and implications of ex vivo surgery are discussed, highlighting the increased operative risk, perioperative mortality, and poor long-term results in patients with malignant tumours.

Echocardiographic assessment of conjoined twins.

OBJECTIVE: To determine the accuracy of prenatal and postnatal echocardiography in delineating the degree of cardiac fusion, intracardiac anatomy (ICA), and ventricular function of 23 sets of conjoined twins with thoracic level fusion presenting to a single centre over a 20 year period. METHODS: 13 thoracopagus, 5 thoraco-omphalopagus, and 5 parapagus pairs presenting to the authors' institution between 1985 and 2004 inclusive were assessed. Echocardiographic data were analysed together with operative intervention and outcome. Twins were classified according to the degree of cardiac fusion: separate hearts and pericardium (group A, n = 5), separate hearts and common pericardium (group B, n = 7), fused atria and separate ventricles (group C, n = 2), and fused atria and ventricles (group D, n = 9). RESULTS: The degree of cardiac fusion was correctly diagnosed in all but one set. ICA was correctly diagnosed in all cases, although the antenatal diagnosis was revised postnatally in three cases. Abnormal ICA was found in one twin only in two group A pairs, one group B pair, and both group C pairs. All group D twins had abnormal anatomy. Ventricular function was good in all twins scanned prenatally, and postnatally function correlated well with clinical condition. Thirteen sets of twins in groups A-C were surgically separated; 16 of 26 survived. None from groups C or D survived. CONCLUSIONS: Prenatal and postnatal echocardiography accurately delineates cardiac fusion, ICA, and ventricular function in the majority of twins with thoracic level fusion. It is integral in assessing feasibility of separation. The outcome in twins with fused hearts remains dismal.

Resection and primary anastomosis is a valid surgical option for infants with necrotizing enterocolitis who weigh less than 1000 g.

HYPOTHESIS: Primary anastomosis following intestinal resection is a valid surgical option in the treatment of infants with necrotizing enterocolitis (NEC) who weigh less than 1000 g. DESIGN: Retrospective case series. SETTING: Tertiary neonatal surgery referral center. PATIENTS: All infants with confirmed NEC weighing less than 1000 g admitted to our intensive care unit over 4 years. INTERVENTION: For infants requiring laparotomy and intestinal resection, primary anastomosis was performed whenever the clinical condition permitted. MAIN OUTCOME MEASURES: Short- and long-term survival, length of intensive care unit stay, and complications. RESULTS: Fifty-one infants with NEC who weighed less than 1000 g were admitted during the study period. Twelve infants underwent intestinal resection and primary anastomosis (median weight at surgery, 0.83 kg; range, 0.6-0.96 kg). One infant developed recurrent NEC, requiring further surgery, but there were no anastomotic leakages and no strictures. The median postoperative stay on our intensive care unit was 14 days (range, 2-49 days). All 12 infants survived their episode of acute NEC, and 8 are alive, with a median follow-up of 34.2 months (range, 4.7-48.4 months). Only 1 death was related to NEC. During the same period, 14 infants underwent intestinal resection and stoma formation. Ten survived the acute episode, and 6 are alive at a median follow-up of 24.0 months (range, 13.1-33.9 months). The median postoperative intensive care unit stay was 18 days (range, 2-74 days). Necrotizing enterocolitis-related complications occurred in 8 of these infants. CONCLUSIONS: The outcome of infants with NEC who weigh less than 1000 g and undergo primary anastomosis is comparable to that of infants treated using alternative techniques. It is, therefore, a valid surgical option in selected infants. The mortality in this group of infants is high.

Peritoneovenous shunting is an effective treatment for intractable ascites.

AIM AND METHODS: A retrospective review was carried out of children undergoing peritoneovenous shunting for intractable ascites. RESULTS: 11 children, aged 3 months to 12 years (median 31 months) underwent peritoneovenous shunting over the past 17 years. The duration of ascites ranged from one month to 2.5 years (median two months). The primary pathology consisted of previous surgery in eight (three neuroblastoma, one renal carcinoma, one hepatoblastoma, one adrenal teratoma, one renal artery stenosis, and one diaphragmatic hernia), and cytomegalovirus hepatitis, lymphatic hypoplasia, and lymphohistiocytosis in one patient each. All patients had failed to respond to previous treatment including peritoneal drainage in six patients, diuretics in five, and parenteral nutrition in five. There were no intraoperative problems. Postoperative complications included pulmonary oedema in three patients, shunt occlusion in three, infection in two, and wound leakage in one. Ascites resolved after shunting in 10 patients. Five shunts were removed one to three years after insertion without recurrence of ascites. Three others are free of ascites with shunts in place for less than one year postoperatively. Three children died from their underlying disease: two after resolution of ascites (neuroblastoma) and one in whom the ascites failed to resolve (lymphohisticytosis). CONCLUSIONS: Peritoneovenous shunting is an effective treatment for symptomatic intractable ascites in children (10 of 11 successful cases in this series). Elective removal of the shunt after one year is recommended.

H-type tracheo-oesophageal fistula with congenital oesophageal stenosis.

H-type tracheo-oesophageal fistula (H-TOF) and congenital oesophageal stenosis (COS) are both rare anomalies. Only six cases of H-TOF in association with COS have been described in the literature. Characteristically, diagnosis is delayed, often well beyond the neonatal period. We report a patient who was accurately diagnosed on day 12 of life, and outline several of the key clinical dilemmas encountered in managing a neonate with this combination of rare congenital anomalies.

A histological study of the hph-1 mouse mutant: an animal model of phenylketonuria and infantile hypertrophic pyloric stenosis.

AIM: To quantify the chronological sequence of changes in the morphology and immunoreactivity for neurotransmitters in the pylorus of an animal model of infantile hypertrophic pyloric stenosis and phenylketonuria. METHOD: Thirty specimens of pylorus from hph-1 mice and age/sex matched controls (age range: 10-180 days) were examined using conventional histology and immunohistochemistry for a variety of antigens: protein gene product 9.5, a pan neuronal marker; vasoactive intestinal polypeptide; nitric oxide synthase two antigens coalesced to the same inhibitory neurons in humans; substance P, a potent excitatory neurotransmitter; and calcitonin gene related peptide, a neurotransmitter implicated in the somatic afferent innervation of the stomach. The changes in the morphology of the muscle layers were quantified and statistically analysed for each age group (10, 20, 40, 90 and 180 days). RESULTS: Between 10 and 90 days of age, all muscle layers of the hph-1 mice were hypertrophied, for example, 10 days, hph-1 longitudinal muscle mean diameter = 3.4, control = 1.8; hph-1 circular muscle width = 11.5, control = 4.7. The hph-1 mice were significantly smaller during this period (40 days, hph-1 weight = 10 g, control = 25 g). There was no change in the pattern of expression of the antigens examined within the hph-1 mice compared with the controls. CONCLUSION: Hph-1 mice develop a transient smooth muscle hypertrophy of the pylorus attended by gastric distension and failure to gain weight. These changes resolve as the pyloric muscle hypertrophy resolves.

Seamless management of biliary atresia in England and Wales (1999-2002).

BACKGROUND: Before 1999, infants born in the UK with suspected biliary atresia were investigated in regional centres, and, if confirmed, a Kasai operation was done there. Since 1999, all infants with suspected biliary atresia in England and Wales, UK, have been referred to one of three designated centres where both the Kasai operation and liver transplantation (if necessary) could be done. METHODS: We assessed clearance of jaundice (bilirubin <20 micromol/L) as an early outcome in all cases of biliary atresia referred from one of the three centres. We then estimated survival using the Kaplan-Meier method with endpoints of liver transplantation or death. FINDINGS: 148 infants with biliary atresia were treated between January, 1999, and June, 2002. A primary portoenterostomy was done in 142 (96%) infants and a primary liver transplant in five (3%). One child died before any intervention. Early clearance of jaundice after portoenterostomy was achieved in 81 of 142 (57%) infants. Liver transplantation was done in 52 (37%) of those undergoing portoenterostomy. 13 (9%) infants died. Of the 135 children who survived, 84 (62%) still have their native liver and 51 (38%) had transplantation. The median follow-up of survivors was 2.13 (range 0.5-4.1) years. The overall 4-year estimated actuarial survival was 89% (95% CI 82-94). The 4-year estimated actuarial survival with native liver was 51% (42-59%). INTERPRETATION: Our early results suggest that surgical outcome can be improved by centralisation of care to supra-regional centres.

Outcome and complications after resection of hepatoblastoma.

PURPOSE: The aim of this study was to review the outcome and complications after resection of hepatoblastoma treated over 2 decades in our institution. METHODS: Clinical, radiologic, and pathologic data were reviewed retrospectively, focusing on the outcome and complications. RESULTS: Between January 1978 and December 2002, 56 children were treated for hepatoblastoma. The age range was 0.08 to 8.74 years (median, 1 year). The right lobe was involved in 48%, the left lobe in 22%, and in 29% the main bulk of the tumour was centrally located. Surgical procedures included the following: hemihepatectomy in 62%, trisegmentectomy in 18%, extended hemihepatectomy in 16%, and liver transplantation and laparotomy in one patient each. Intraoperative complications occurred in 5(9%)--rupture of the tumour (1), haemorrhage from the contralateral lobe (1), a defect in the left hepatic duct (1), cardiac arrest from tumour embolus (1), and bleeding from the inferior vena cava (1). The mean blood loss was 280 mL (50 to 2,000 mL). Postoperative complications occurred in 12 patients (22%) including subphrenic abscess (3), adhesion obstruction (2), ischaemic stenosis of the bile duct (1), abdominal wound dehiscence (1), pyloric obstruction (1), and pleural effusion (2). Fifteen patients died, 14 as a result of tumour recurrence (mortality rate, 27%).

Myocardial carnitine palmitoyltransferase I as a target for oxidative modification in inflammation and sepsis.

CPT I (outer membrane carnitine palmitoyltransferase I) is a crucial enzyme in myocardial substrate selection. Two isoforms exist in the heart, the liver (L-) and muscle (M-) isoforms, which have different kinetic characteristics and alter in relative amounts during the neonatal/weaning/adult transition. CPT I is a point for control and regulation of fatty acid oxidation via modulation of its activity by malonyl-CoA, the concentration of which is set by acetyl-CoA carboxylase, AMP-activated protein kinase and malonyl-CoA decarboxylase in response to, for example, alterations in glucose supply. Systemic inflammatory responses and sepsis lead to myocardial dysfunction as part of multiple system organ failure. We have shown that: (i) myocardial CPT I activity is inhibited during neonatal sepsis; (ii) on the basis of inhibitor studies this inhibition appears to be of M-CPT I rather than L-CPT I; (iii) nitration of M-CPT I occurs, probably by peroxynitrite, and this may be responsible for the decrease in CPT I activity; (iv) myocardial CPT I activity is also inhibited in another model of systemic inflammatory response, namely intestinal ischaemia/reperfusion injury, but this can prevented by whole-body moderate hypothermia. Inhibition of M-CPT I would be predicted to alter myocardial substrate selection but there are several questions that remain to be answered.

Gastroesophageal reflux.

Gastroesophageal reflux is common in infants and generally resolves spontaneously within the first year of life as the lower esophageal sphincter mechanism matures. The reflux is only considered a "disease" (GERD) when it becomes symptomatic or causes pathological consequences. GERD is commonly associated with esophageal atresia and there is a high incidence in neurologically impaired children; in both groups conservative treatment is notoriously ineffective. The diagnosis of GER is made on upper gastrointestinal contrast studies, endoscopy and pH monitoring. Medical management comprises antacids, reduction of gastric acid production and prokinetic agents. The indications for antireflux surgery include an established esophageal stricture, associated anatomical defect and failure of medical therapy. Apnoeic episodes secondary to documented GER in the infant, constitute an absolute indication for early surgery.

Dysphagia caused by a foreign body.

A boy with a long history of dysphagia attributed to neurological impairment was shown to have a large oesophageal foreign body. It had remained undetected for five years as a central lumen allowed the passage of liquids and semisolids. Foreign bodies must be excluded in children with dysphagia.

Neonatal intrathoracic stomach in Marfan's syndrome: report of two cases.

The authors report experience with 2 neonates with the unusual combination of intrathoracic stomach and Marfan's syndrome.

The association of anorectal leiomyomatosis and diffuse oesophageal leiomyomatosis.

Anorectal leiomyomatosis is exceedingly rare in children. Its association with the more common diffuse oesophageal leiomyomatosis has been documented in only two previous cases. This report describes the presentation, diagnosis and treatment of two further cases of diffuse oesophageal combined with anorectal leiomyomatosis.