Role of tenecteplase (rtPA) to re-establish flow in intraprocedural stent thrombosis in infants undergoing ductal stenting for duct-dependent pulmonary circulation—a case series

Ductal stenting in patients with duct-dependent pulmonary circulation has allowed growth of pulmonary arteries prior to definitive surgical procedures. Intraprocedural stent thrombosis (IPST) of the arterial duct is a life-threatening complication as it leads to total circulatory collapse. Previous reports have described use of tissue plasminogen activators in infants for less emergent settings. We report three infants with IPST and the use of tenecteplase to overcome this. Also discussed are the predisposing mechanisms in each scenario and a possibility of direct catheter-guided tenecteplase administration. Judicious use of tenecteplase can be life-saving and rapid access to this drug may obviate the need for emergency extracorporeal life support.     

Growth performance of selected taxa as candidate species for productive tree plantations in Borneo

ABSTRACT

The establishment of commercial tree plantations in Malaysian Borneo began with a progression of various species, including Pinus caribea, Acacia mangium, Gmelina arborea, Falcataria moluccana (formerly Albizia falcataria) and Eucalyptus deglupta. Ultimately, A. mangium, intended for the production of pulplogs, dominated the plantation landscape. However, recent widespread devastation of A. mangium by the Ceratocystis pathogen in Sabah has led to a shift in plantation species, which has also necessitated a review of downstream end products. This paper analyses growth data and estimates productivity for species in a taxa trial as well as a F. moluccana progeny trial in a single trial area in Sabah. A eucalyptus hybrid (Eucalyptus urophylla x Eucalyptus grandis (UG)), Eucalyptus pellita, F. moluccana, Acacia crassicarpa and A. mangium exhibited high productivity after three years, with an average mean annual increment of approximately 35 m³ ha^?1 y^?1 or better. Mean annual increment curves show that productivity declined slightly for the eucalypts and F. moluccana after three years. Acacia species experienced a sharper decline associated with disease-caused mortality, with A. mangium the most seriously affected. The mean basic density of the UG hybrid and F. moluccana was 560 kg m^?3 and 252 kg m^?3 at six and five years of age, respectively, and E. pellita had a mean basic density of 629 kg m^?3 at six years of age. The importance of growth and wood properties in the selection of species suitable for planted forest development in the wet tropics is discussed.     

The Amplatzer duct occluder: experience in 209 patients

OBJECTIVES: The aim of the study was to assess the safety and efficacy of the Amplatzer ductal occluder (ADO) in transcatheter occlusion of patent ductus arteriosus (PDA). BACKGROUND: Transcatheter closure of small to moderate sized PDAs is an established procedure. The ADO is a self-expandable device with a number of salutary features, notably its retrievability, ease of delivery via small 5F to 7F catheters and a range of sizes suitable even for the larger PDAs. METHODS: Between November 1997 and August 1999, the ADO was successfully implanted in 205 of 209 patients with PDA. The inclusion criteria for this device occlusion method were patients with clinical and echocardiographic features of moderate to large PDA, weighing > or =3.5 kg as well as asymptomatic adolescents and adults with PDA measuring > or =5.0 mm on two-dimensional (2D) echocardiogram. Occlusion was achieved via the antegrade venous approach. Follow-up evaluations were performed with 2D echocardiogram, color-flow mapping and Doppler measurement of the descending aorta and left pulmonary artery velocity at 24 h and 1, 3, 6 and 12 months after implantation. RESULTS: Two hundred and five patients had successful PDA occlusion using this device. The patients were between two months and 50 years (median 1.9) and weighed between 3.4 kg and 63.2 (median 8.4). Infants made up 26% of the total patients. The PDA measured from 1.8 to 12.5 mm (mean 4.9) at the narrowest diameter. Forty-four percent of patients achieved immediate complete occlusion. On color Doppler the closure rates at 24 h and 1 month after implant were 66% and 97%, respectively. At 6 and 12 months all except one patient attained complete occlusion. Device embolization occurred in three patients; in two this was spontaneous, and in the other it was due to catheter manipulation during postimplant hemodynamic measurement. Mild aortic narrowing was seen in an infant. CONCLUSIONS: Patent ductus arteriosus occlusion using ADO is safe and efficacious. It is particularly useful in symptomatic infants and small children with relatively large PDA. Embolization can be minimized by selection of appropriate sized devices, and caution should be exercised in infants <5 kg.     

Initial results and medium-term follow-up of stent implantation of patent ductus arteriosus in duct-dependent pulmonary circulation

OBJECTIVES: This study was designed to assess the safety, efficacy, medium-term outcome, and complications of patent ductus arteriosus (PDA) stenting in duct-dependent pulmonary circulation. BACKGROUND: Patent ductus arteriosus stenting has been proposed as an alternative to surgical shunt on account of postoperative morbidity and complications of surgical shunting. METHODS: Between April 2000 and February 2003, 69 patients with duct-dependent pulmonary circulation underwent cardiac catheterization with the intent of PDA stenting as first palliative procedure. Patients with critical pulmonary stenosis and pulmonary atresia with intact ventricular septum post-radiofrequency valvotomy who had PDA stenting were excluded. Thirteen more patients were excluded because of branch pulmonary artery (PA) stenosis. The follow-up was by clinical examination, echocardiography, and repeat cardiac catheterization at six to nine months following the procedure. RESULTS: Patent ductus arteriosus stenting was successful in 51 patients (91.1%) and failed in 5 patients (8.9%). The mean narrowest PDA diameter was 1.9 +/- 0.6 mm. The mean procedure and fluoroscopy time were 95.7 min and 29.4 min, respectively. In one patient the stent dislodged and migrated to the left femoral artery and another patient developed transient intravascular hemolysis. There was no procedure-related mortality. Three patients (5.9%) died one day to two months after the procedure. At follow-up (3.2 months to 2.4 years), 8 patients developed significant stent stenosis requiring reintervention. Seven patients developed worsening of preexisting branch PA stenosis. The freedom from reintervention was 89% and 55% at 6 months and 1 year, respectively. CONCLUSIONS: Patent ductus arteriosus stenting is an attractive alternative to surgical shunt in a majority of patients with duct-dependent circulation. An absolute contraindication to this technique is the presence of branch pulmonary stenosis.     

Management algorithm in pulmonary atresia with intact ventricular septum.

Pulmonary atresia with intact ventricular septum (PAIVS) is a disease with remarkable morphologic variability, affecting not only the pulmonary valve but also the tricuspid valve, the RV cavity and coronary arteries. With advances in interventional techniques and congenital heart surgery, the management of PAIVS continues to evolve. This review is an attempt at providing a practical approach to the management of this disease. The basis of our approach is morphologic classification as derived from echocardiography and angiography. Group A, patients with good sized RV and membranous atresia, the primary procedure at presentation is radiofrequency (RF) valvotomy. Often it is the only procedure required in this group with the most favourable outcome. Patients with severely hypoplastic RV (Group C) are managed along the lines of hearts with single ventricle physiology. The treatment at presentation is patent ductus arteriosus (PDA) stenting with balloon atrial septostomy or conventional modified Blalock Taussig (BT) shunt. Bidirectional Glenn shunt may be done 6-12 months later followed by Fontan completion after a suitable interval. Patients in Group B, the intermediate group, are those with borderline RV size, usually with attenuated trabecular component but well developed infundibulum. The treatment at presentation is RF valvotomy and PDA stenting +/- balloon atrial septostomy. Surgical re-interventions are not uncommonly required viz. bidirectional Glenn shunt when the RV fails to grow adequately (11/2 - ventricle repair) and right ventricular outflow tract (RVOT) reconstruction for subvalvar obstruction or small pulmonary annulus. Catheter based interventions viz. repeat balloon dilatation or device closure of patent foramen ovale (PFO) may also be required in some patients.     

Session 1.2: national health perspectives of the Tsunami crisis

This is a summary of the presentations and discussion of Session 1.2 of the Conference, Health Aspects of the Tsunami Disaster in Asia, convened by the World Health Organization (WHO) in Phuket, Thailand, 04-06 May 2005. The topics discussed included issues related national health perspectives as pertaining to the responses to the damage created by the Tsunami. It is presented in the following major sections: (1) key questions; (2) discussion; (3) what was done well?; (4) what could have been done better?; and (5) what can be done to prepare for the future?.