Selenium homocholic acid taurocholate scanning, selenium-75-labeled bile acid, a novel method for testing the function of the terminal ileum in small bowel transplant recipients: a pilot study.

INTRODUCTION: The terminal ileum (TI) is important for the active reabsorption of bile salts and is the site of allograft rejection; disruption of enterohepatic circulation (EHC) may give insights to inflammatory and other physiologic processes at the TI. SUBJECTS AND METHODS: Four children aged 5 to 12 years who had received small bowel transplantation (SBTx), 3 recovering from post-transplant lymphoproliferative disease (PTLD) and 1 with acute rejection, were studied. Two of the 4 had stoma reversal. Another child (15 years) with progressive familial intrahepatic cholestasis (PFIC) and pruritus, despite liver transplantation and biliary diversion, was studied. Selenium homocholic acid taurocholate scanning ((75)SeHCAT) capsule was given orally (n = 3) or via introducer during endoscopy (n = 2); a baseline whole-body gamma camera scan was done 4 hours later and on days 1 to 5. RESULTS: The normal 3-day bile salt retention is 30% to 70% of baseline and normal adult biological half-life, t½ is 62 ± 17 hours. The results in children with a stoma were very low (0.1% at 7.6 hours; 5% at 17 hours). The children with reversed stoma had retention and t½ closer to the reference range (18% at 29 hours; 22% at 33 hours). The child with PFIC + biliary diversion had an initial very high gamma emission from the stoma bag suggesting excellent reabsorption of bile salts from his TI, but retention was 0.6% and t½ 9.8 hours, demonstrating efficient biliary diversion. CONCLUSION: These results confirm children with stomas malabsorb bile acids, which can be ameliorated after stoma closure. SeHCAT demonstrated that the biliary diversion was working well and may be helpful in preoperative assessment of abnormal EHC. The role of SeHCAT in SBTx requires further evaluation.

Pneumonia in the immunocompetent patient.

Pneumonia is an acute inflammation of the lower respiratory tract. Lower respiratory tract infection is a major cause of mortality worldwide. Pneumonia is most common at the extremes of life. Predisposing factors in children include an under-developed immune system together with other factors, such as malnutrition and over-crowding. In adults, tobacco smoking is the single most important preventable risk factor. The commonest infecting organisms in children are respiratory viruses and Streptoccocus pneumoniae. In adults, pneumonia can be broadly classified, on the basis of chest radiographic appearance, into lobar pneumonia, bronchopneumonia and pneumonia producing an interstitial pattern. Lobar pneumonia is most commonly associated with community acquired pneumonia, bronchopneumonia with hospital acquired infection and an interstitial pattern with the so called atypical pneumonias, which can be caused by viruses or organisms such as Mycoplasma pneumoniae. Most cases of pneumonia can be managed with chest radiographs as the only form of imaging, but CT can detect pneumonia not visible on the chest radiograph and may be of value, particularly in the hospital setting. Complications of pneumonia include pleural effusion, empyema and lung abscess. The chest radiograph may initially indicate an effusion but ultrasound is more sensitive, allows characterisation in some cases and can guide catheter placement for drainage. CT can also be used to characterise and estimate the extent of pleural disease. Most lung abscesses respond to medical therapy, with surgery and image guided catheter drainage serving as options for those cases who do not respond.

Sirolimus-related pulmonary toxicity mimicking 'asthma like' symptoms.

Sirolimus is an immunosuppressant with expanding use in pediatric organ transplantation, dermatology and rheumatology. We report two cases of children who developed asthma like symptoms and were diagnosed with interstitial lung disease, which responded to discontinuation of sirolimus. Pediatricians should be aware about the pulmonary side effects of sirolimus.

A case of pituitary adenoma: Thomas Willis revisited.

Thomas Willis (1621-1675) was the founder of modern clinical neuroscience. His habit of taking detailed histories with acute clinical observation often accompanied by post mortem studies has left a body of work which still provokes thought and debate. While we were considering a case of pituitary tumour described by Willis, a similar case presented coincidentally at our hospital. The two cases are compared and contrasted.

Imaging of paediatric mediastinal abnormalities.

The mediastinum in children can be a difficult area to assess on the chest radiograph: even the normal thymus can give the impression of a mediastinal mass lesion. When there is suspicion of a mediastinal mass, its location within the mediastinum helps to limit the differential diagnosis. Further imaging with ultrasound, computed tomography and magnetic resonance imaging helps to characterise the lesion, define its extent and detect complications. Abnormal mediastinal contours may also be caused by congenital anomalies of the mediastinal vessels, which can be demonstrated non-invasively using magnetic resonance imaging. The main purpose of this article is to review the anatomy of the mediastinum and imaging of mediastinal mass lesions in children together with some vascular anomalies that can simulate a mediastinal mass.

Pulmonary vascular imaging.

This article is a pictorial review of the major abnormalities of the pulmonary vessels in children. Vascular, including lymphatic malformations have been covered in previous issues of this journal and so will not be described in detail. Many pulmonary vascular abnormalities are associated with complex intracardiac disorders. This article, however, focuses on extra cardiac abnormalities, particularly those causing pulmonary parenchymal problems.

Microscopic polyarteritis with renal and cerebral involvement.

We report a 15-year-old girl who presented with renal failure requiring dialysis and a diagnosis of p-ANCA-associated vasculitis. She subsequently developed cerebral vasculitis during treatment with oral cyclophosphamide and prednisolone. Treatment with intravenous cyclophosphamide and plasma exchange produced a complete recovery.

Myocardial perfusion scanning in patients considered for late arterial switch.

BACKGROUND: Our aims were to evaluate left ventricular uptake of radionuclide in patients with Mustard's or Senning's procedure, comparing them with patients who had undergone banding of the pulmonary trunk and conversion to the arterial switch. METHODS: Technetium perfusion scans were performed on 27 patients (25 male), aged from 10 to 28 years with a mean of 17.8 years and a standard deviation of 5.8 years, who had undergone Mustard's or Senning's procedure for correction of complete transposition. Of the 27 patients, six had been accepted for staged conversion to an arterial switch. At the time of the study, two of the six patients had undergone completion to the switch and four had undergone banding of the pulmonary trunk with two then proceeding to the arterial switch. Cardiac catheterisation to measure left ventricular pressure was performed in all six patients and scores for left ventricular uptake of isotope were compared with echocardiographic index of the thickness of the left ventricular posterior wall and measurements of left ventricular pressure. RESULTS: Uptake of isotope by the left ventricle was generally poor, but was higher in patients following banding and conversion to the arterial switch, as well as in two patients with native obstruction of the left ventricular outflow tract, and one other who subsequently was found to have pulmonary venous obstruction. There was a positive correlation between the thickness of the left posterior wall in diastole and left ventricular uptake of isotope (r = 0.74, p < 0.05). There also a positive correlation between left ventricular pressure and uptake of the isotope (r = 0.68, p < 0.05). CONCLUSIONS: Uptake of radionuclide by the left ventricle after Mustard's or Senning's procedure for complete transposition appears to reflect ventricular pressure and myocardial mass. A prospective study would be required to determine the predictive ability of such scans regarding the ultimate outcome of conversion to arterial switch, but our initial findings suggest that the technique provides an additional non-invasive method of monitoring left ventricular response to pulmonary arterial banding.

Spontaneous rupture of the diaphragm.

A 2.5 year old girl with metachromatic leukodystrophy presented with acute respiratory distress and was initially wrongly diagnosed with pneumothorax. Barium meal showed bowel loops in the left hemithorax, which prompted surgical intervention; spontaneous rupture of the diaphragm was diagnosed at surgery.

Evaluation of mebrofenin hepatoscintigraphy in neonatal-onset jaundice.

BACKGROUND: The prognosis of infants with prolonged neonatal jaundice is dependent on early diagnosis because of the need for prompt surgical management of biliary atresia. OBJECTIVE: To evaluate the usefulness of 99 mTcm-trimethylbromo-iminodiacetic acid (TBIDA, mebrofenin) in the investigation of infantile jaundice. MATERIALS AND METHODS: A retrospective study was undertaken of 58 patients with unexplained prolonged neonatal jaundice. Sixty-eight scans were reviewed. RESULTS: Mebrofenin scintigraphy confirmed the presence of a choledochal cyst in three of the four cases with that diagnosis. There were no false negative results in the nine patients with extrahepatic biliary atresia (EHBA). Three further infants had an incorrect histological diagnosis of EHBA. A gall bladder was identified by US in each case and in one of these, scintigraphy showed gut excretion. In the 16 patients with no gut excretion by 24 h, the final diagnoses were intrahepatic cholestasis (n = 7), Alagille's syndrome (n = 3), neonatal hepatitis (n = 3), alpha-1-antitrypsin deficiency (n = 2) and juvenile xanthogranuloma (n = 1). Seven infants had repeat scintigraphy after the administration of ursodeoxycholic acid (URSO). This changed five non-excretors with hepatitis into excretors. Two infants with hepatitis continued to show non-excretion after URSO, but a gallbladder was identified by US in both. CONCLUSIONS: Mebrofenin scintigraphy is accurate in confirming the presence of a choledochal cyst and in refuting the diagnosis of EHBA. While histology and scintigraphy are each 100 % sensitive for the diagnosis of EHBA, neither, individually, is accurate and the investigation of prolonged neonatal jaundice requires a multi-modality imaging strategy.

Combined percutaneous lung biopsy and high-resolution computed tomography in the diagnosis and management of lung disease in children.

Computed tomography-guided percutaneous lung biopsy is a well-recognized procedure for obtaining tissue for diagnosis in adults with interstitial lung diseases. Recently this methodology has been extended to pediatric practice. We have further refined this technique by employing high-resolution computed tomography (HRCT) under general anesthesia to obtain maximum anatomical detail. High-quality images are obtained that accurately define the extent of disease, and percutaneous biopsies are then taken from a suitable area of radiological abnormality using an 18G Monopty needle. Twenty-six investigations have been performed on 24 patients. The diagnosis was established from 14 biopsies, and histological and/or radiological information that contributed to patient management was obtained from a further 4 procedures. In 4 patients the histological findings were inconclusive, and the final diagnosis was only confirmed by open lung biopsy and/or other investigations. The procedure was generally well tolerated, although chest drainage for pneumothorax was required in two patients. HRCT-guided percutaneous lung biopsy is a useful initial approach to the diagnosis of interstitial lung disease in selected patients; the necessity of more invasive procedures such as open, thoracoscopic, or transbronchial lung biopsy can thus generally be avoided.

Hypercalciuria and ultrasound abnormalities in children with cystinosis.

We noted microscopic haematuria in children with cystinosis. To investigate this we studied urinary calcium excretion and undertook renal ultrasound scans. Most patients had elevated urinary calcium excretion and all had abnormal appearances on ultrasound scan, ranging from increased cortical echogenicity only to those with increased cortical and medullary echogenicity. The ultrasound scan appearance was graded and correlated with laboratory parameters. It remains unclear as to the aetiology of the ultrasound findings and whether they are a consequence of treatment or a hitherto unrecognised feature of the disease.

Duplex Doppler detection of hepatic artery thrombosis following liver transplantation.

Hepatic artery thrombosis is a major cause of morbidity and mortality following liver transplantation. We assessed the value of prospective duplex Doppler ultrasound in detecting hepatic artery thrombosis. One hundred consecutive transplants in 90 patients were studied. Duplex Doppler detected all 10 proven cases of hepatic artery thrombosis. No case of hepatic artery thrombosis was found with a normal duplex study. All arteriograms performed following an abnormal ultrasound demonstrated hepatic arterial occlusion or anastomotic stenosis or a segment of irregular arterial narrowing. We conclude that duplex Doppler is a practical and sensitive method of selecting patients with a presumptive diagnosis of hepatic artery thrombosis for further investigation by angiography.

Aspiration of foreign materials in children while under general anesthesia for dental extractions.

Airway aspiration of foreign materials in children and adults is probably more common than has been supposed. This study investigated the possibility of such aspiration in children while under general anesthesia for dental extractions. A radiopaque fluid was used to coat the oral tissues and showed that a significant number of children did aspirate material into the trachea, bronchi, and occasionally even lung tissue. The notion that safety may be improved by operating with the patient in the supine position was not confirmed. While careful placement of an oropharyngeal pack may prevent solid material from entering the trachea and bronchi, it should be realized that fluids such as blood, saliva, and pus could still contaminate the airway.

Cavopulmonary anastomosis as long-term palliation for patients with tricuspid atresia.

Prior to 1970, most patients with tricuspid atresia (TA) and reduced pulmonary blood flow were palliated by means of a systemic to pulmonary artery shunt (SPAS). In Birmingham between 1967 and 1988, 19 patients with TA (aged 16 days to 23 years, mean 3.8 years) have undergone side-to-side cavopulmonary anastomosis (CPA) with preservation of pulmonary artery continuity. One had undergone a previous right Blalock-Taussig shunt and in 1 patient with left and right SVCs, bilateral CPAs were performed. Nine patients were less than 1 year old at the time of operation. There were no operative deaths. One late death occurred due to pneumonia. Immediate clinical improvement occurred in all cases. Six symptomatic patients subsequently required further surgery (mean interval between operations 8.9 years, range 4.6-14.2 years). The remaining 12 patients have recently been reviewed. Mean follow-up was 9.5 years (range 5 weeks to 21 years). Exercise tolerance remains good (9 in NY-HA Class 1 or 2) and resting transcutaneous oxygen saturations are higher (mean 85%, range 70%-89%) compared with preoperative values (P less than 0.01). In small children, CPA avoids the complications of SPAS and, in some patients, may itself achieve adequate long-term definitive palliation.