Emergency transcatheter balloon recanalization of acutely thrombosed modified Blalock-Taussig shunts.

BACKGROUND: Modified Blalock-Taussig shunts are used to palliate a variety of cyanotic heart diseases associated with reduced pulmonary blood flow. Acute shunt thrombosis in patients with shunt-dependent pulmonary blood flow can result in life-threatening hypoxia. We describe our experience of emergency transcatheter recanalization in 5 severely hypoxic children with acute shunt occlusion. METHODS AND RESULTS: Five patients with ages ranging between 5 and 24 months (median 11 months) and weight ranging from 4 to 8 kg (median 5 kg) presented with severe hypoxia, acidosis and hypotension following acute occlusion of modified Blalock-Taussig shunts placed 11 days to 12 months ago. As severe hypoxia (saturation range 3 5%-5 0%), acidosis and a state of shock in all the patients increased the risk for a redo surgical procedure, they were taken up for emergency transcatheter recanalization within 2-6 hours of hospitalization. This was done by positioning a Judkin's right coronary catheter at the mouth of the thrombosed shunt, crossing the shunt with a guidewire and serial dilatations with coronary and/or peripheral angioplasty balloons to the size of the graft. This technique was immediately successful in 4 of the 5 patients, thereby avoiding a repeat palliative operation. In 2 patients with residual stenosis, stents were used to restore luminal patency. One patient with acute stent thrombosis was managed successfully with local delivery of thrombolysis for 36 hours, which resulted in good luminal patency. At follow-up after 6 and 12 months, the shunts in both the stented patients are patent, with an oxygen saturation of 78% and 80%, respectively. In 2 other patients who had undergone plain balloon angioplasty, the shunts remained patent for 11 days (died of bronchopneumonia and septicemia) and 3 months, respectively. The procedure was unsuccessful in one very sick patient in whom the shunt had a tortuous course. CONCLUSIONS: Transcatheter recanalization of an acutely thrombosed Blalock-Taussig shunt is feasible. It can offer satisfactory short-term palliation in selected patients. Stents may play a role in patients with residual narrowing after dilatation. The procedure can be expeditiously accomplished in an emergency situation in a severely hypoxic child and may be a realistic alternative to surgery or thrombolysis.

Operative outcome and intermediate term follow-up of neonatal Blalock-Taussig shunts.

BACKGROUND: The neonatal age group is considered to be one of the important risk factors for perioperative morbidity and mortality as well as poor long-term patency following Blalock-Taussig shunts. METHODS AND RESULTS: Out of a total of 190 patients who underwent Blalock-Taussig shunts in our institute between July 1998 and July 2000, 20 patients were aged less than 30 days and this neonatal cohort was studied retrospectively. The mean age was 18+/-11 days (range: 3-30 days). The mean weight of the babies was 3.1+/-0.7 kg, the smallest weighed 2.1 kg. The cardiac anatomy was tetralogy of Fallot with pulmonary atresia in 6, pulmonary atresia with intact ventricular septum in 3, tricuspid atresia in 5 and complex single ventricle physiology in the rest. All patients were deeply cyanotic and preoperative prostaglandin E1 was needed in 10 patients to ensure ductal patency and maintain oxygen saturations prior to the shunt operation. The mean hilar right and left pulmonary artery sizes were 3.99+/-0.44 mm and 3.69+/-0.79 mm, respectively. Three patients (15%) had significant stenosis at the site of duct insertion. The shunts were accomplished with 3.5 mm polytetrafluoroethylene grafts in 7 patients (35%) and 4 mm in the rest. The mean duration of mechanical ventilation was 2.0+/-2.83 days, one patient who developed bronchopneumonia needed prolonged ventilation for 14 days. The mean intensive care unit stay was 4.79+/-2.66 days. The mean hospital stay was 11.7+/-6.4 days. Five patients who developed sepsis stayed beyond 14 days. There were 3 deaths (immediate post-operative shock and possibly shunt malfunction in 1, bronchopneumonia in 1 and late shunt thrombosis at 3 months in 1). Two patients had late shunt block, one of those mentioned above and the other at 3 months secondary to infective endarteritis of the right pulmonary artery. All these infants received 4 mm grafts. All the 3.5 mm grafts were patent at follow-up. Seventeen patients were alive and well at follow-up (mean: 9 months, range: 3-21 months) with a mean resting systemic oxygen saturation of 77% (66%-95%). CONCLUSIONS: The overall shunt patency rate after neonatal Blalock-Taussig shunt is about 80% on intermediate term follow-up. A smaller graft size (3.5 mm) does not appear to be an incremental risk factor for shunt blockade and operative mortality.

Bronchial asthma: recent advances.

Asthma is one of the oldest diseases about which there are lots of myths in most parts of the world. The exact cause of this global disease still eludes scientists. The recent knowledge about the pathogenesis of the disease, led to rationalise the medications into different groups. Parallel to the increasing incidence of this disease, is the knowledge about the trigger factors and steps to reduce their exposure. Childhood asthma is a lot different from asthma in adults, as many children won't be able to use the inhalers like adults and most children will not be able to do lung function tests until they are about 6 years of age. Unlike for any other diseases, research has helped year after year in developing new strategies for management of asthma. Starting from definition of the disease to inventing newer medications, management of asthma has revolutionised in the last few years and has also accounted for the decreasing mortality in many countries. This article tries to give an overview of bronchial asthma in children including recent advances and possible future developments.

Neonatal cerebral infarction: USS or CT for imaging?

Neonatal cerebral infarction or neonatal stroke is the second most common cause of neonatal seizures in term new born babies. It remains one of the least recognised entities in the neonatal text books and the awareness of its existence among general practitioners and practising paediatricians is very low. Cranial Ultrasound Scan (USS) is the standard imaging used by neonatologists and many neonatal intensive care units have their own scanners. However, USS may give a false sense of security especially in the term neonates and we report a case of neonatal cerebral infarction here and the need for computerised tomography (CT) for imaging.

Thrombolytic therapy in infants for femoral artery thrombosis following cardiac catheterisation.

Little information is available on the use of thromobolytic therapy in infants for femoral artery thrombosis after cardiac catheterisation. We report 12 cases (mean age: 4 months; range: 1-9 months) who received intravenous streptokinase (3000 U/kg bolus, 1000 U/kg/h) infusion. Five of them had undergone transarterial balloon dilatation procedures. Streptokinase was administered 48 h after catheterisation and continued for 4-20 h (mean 11.5 h). No detailed haematologic monitoring was done during therapy. Distal pulses were restored in all the patients. No complications were seen except a minor local ooze in two patients. We found that intravenous streptokinase is a safe and effective therapy for femoral artery thrombosis following cardiac catheterisation in infants.

Collateral arteries in the presence of obstructive coronary disease.

BACKGROUND. The clinical importance of coronary collaterals in the presence of obstructive coronary artery disease is not clearly defined. METHODS. We retrospectively analysed the clinical and angiographic features of 100 patients with > or = 90% luminal diameter stenosis involving at least one major coronary artery. Coronary collaterals were graded 0 to 4 (Nitzberg's classification) and studied to determine their influence on clinical parameters. RESULTS. Thirty patients had no collaterals (group I) and 70 showed collaterals (group II). There were no significant differences between groups I and II in age and sex distribution, prevalence of risk factors of coronary artery disease (hypertension, diabetes, smoking, hypercholesterolaemia), duration of symptoms of coronary artery disease and prior myocardial infarction. Groups I and II had similar types (left anterior descending 73% v. 71%; left circumflex 50% v. 50% and right coronary 37% v. 56%) and numbers of arteries involved (one 47% v. 41%; two 47% v. 40%; three 7% v. 19%). Group II had a significantly lower prevalence of rest angina (14% v. 47%, p = 0.002). This difference was also evident when the patients were re-classified according to the extent of flow through the collaterals. Those with good collateralization (Nitzberg grades 3 and 4) had a lower prevalence of rest angina (13%) compared to those with poor collateralization (Nitzberg grades 0 to 2; 35%, p = 0.02). CONCLUSION. Coronary artery collaterals may reduce the incidence of rest angina in patients with obstructive coronary artery disease.