Coronary artery stenosis after radiofrequency catheter ablation of accessory atrioventricular pathways in children with Ebstein's malformation.

BACKGROUND: Complications concerning the coronary arteries that are directly related to radiofrequency catheter ablation procedures have not been reported in children. Coronary artery lesions, however, have been demonstrated after the endocardial application of radiofrequency current in young animals. METHODS AND RESULTS: Two boys with Ebstein's anomaly of the tricuspid valve developed clinically asymptomatic coronary artery stenosis after radiofrequency catheter ablation of right-sided accessory atrioventricular pathways with standard catheter technology. CONCLUSIONS: The complication of coronary artery stenosis demonstrates a substantial risk after right atrial free wall radiofrequency current application in children. The risk of late coronary alterations should be considered when the use of catheter ablation procedures to young patients is proposed.

Percutaneous transluminal angioplasty for the treatment of complete arterial occlusion after retrograde cardiac catheterization in infancy.

Nine patients with arterial thrombosis were treated with transcatheter recanalization and subsequent balloon dilation of the occluded vessel. Repeat angiography or duplex sonography 3 to 14 months after intervention showed completely patent arteries without restenosis in 7 patients; there was residual narrowing of the vessel in the remaining 2 patients.

Balloon valvuloplasty in the treatment of congenital aortic valve stenosis--a retrospective multicenter survey of more than 1000 patients.

BACKGROUND: The value of balloon valvuloplasty of the aortic valve in childhood is still under debate. OBJECTIVE: To evaluate the results of the procedure in a retrospective multicenter survey of a large cohort over a long time interval. METHODS: Retrospective analysis of 1004 patients with balloon valvuloplasty of the aortic valve performed between 9/1985 and 10/2006 at 20 centers in Germany, Austria and Switzerland. Amongst others, the following parameters were evaluated before and after the procedure as well as at the end of follow-up or before surgery: clinical status, left ventricular function, transaortic pressure gradient, degree of aortic regurgitation, freedom from re-intervention or surgery. PATIENTS: Patients from 1 day to 18 years of age with aortic valve stenosis were divided into four groups: 334 newborns (1-28 days); 249 infants (29-365 days); 211 children (1-10 years), and 210 adolescents (10-18 years). RESULTS: Median follow-up was 32 months (0 days to 17.5 years). After dilatation the pressure gradient decreased from 65 (± 24)mm Hg to 26 (± 16)mm Hg and remained stable during follow-up. The newborns were the most affected patients. Approximately 60% of them had clinical symptoms and impaired left ventricular function before intervention. Complication rate was 15% in newborns, 11% in infants and 6% in older children. Independently of age, 50% of all patients were free from surgery 10 years after intervention. CONCLUSIONS: In this retrospective multicenter study, balloon valvuloplasty of the aortic valve has effectively postponed the need for surgery in infants, children and adolescents up to 18 years of age.

A novel implantation technique for closure of an atypical fenestration connecting the right atrial appendage to an extracardiac conduit by use of a 15 mm Helex device in a patient with total cavopulmonary connection.

We report on a 7-years old patient after total cavopulmonary anastomosis with an extracardiac conduit. An atypical fenestration was created during the operation connecting the right atrial appendage to the extracardiac conduit. Because of arterial desaturation, the fenestration connecting the anterior wall of the extracardiac conduit to the posterior wall of the right atrial appendage was successfully occluded with a 15 mm Helex device by use of a modified implantation technique.

Endovascular stenting as an emergency treatment for neonatal coarctation.

We describe a neonate with critical coarctation of the aorta. Since treatment with Prostaglandin E1 had failed to reopen the arterial duct, and surgery was deemed to be associated with an unacceptably high risk in this unstable neonate, it was decided to perform balloon dilation of the coarctation as a palliative procedure to stabilize the patient. Balloon angioplasty failed to reduce the pressure gradient across the coarctation, so a stent was implanted retrogradely as an emergency procedure. Subsequently, the stented segment was resected surgically and end-to-end anastomosis created without complications at seven months of age.

Anterograde double-balloon valvoplasty for treatment of severe valvar aortic stenosis in a preterm baby weighing 1400 grams.

We describe our treatment of a premature baby born weighing 1400 g with severe aortic stenosis, with a gradient of 80 mmHg across the valve. Efforts to advance a 6 mm angioplasty catheter into the stenotic aortic valve via the left ventricle failed. Anterograde angioplasty, instead, was performed using two 4 mm coronary angioplasty catheters. Six months subsequent to the intervention, the pressure gradient measured 25 mmHg, and there was no hemodynamically significant aortic insufficiency.

[Percutaneous transcardiac intraluminal balloon angioplasty for reopening an arterial thrombosis after percutaneous arterial heart catheterization in a 19-month-old patient with tetralogy of Fallot]. / Perkutane transkardiale intraluminale Ballonangioplastie zur Wiedereröffnung einer arteriellen Thrombose nach perkutaner arterieller Herzkatheteruntersuchung bei einem 19 Monate alten Patienten mit Fallotscher Tetralogie.

Cardiac catheterization is a common cause of arterial thrombosis in children. Besides heparin therapy, fibrinolysis plays a major role in the therapeutic approaches to arterial thrombosis while surgery is rarely performed in pediatric patients. We report on a 19 month old patient with tetralogy of fallot, who developed thrombosis of the right femoral artery after a retrograde interventional cardiac catheterization. We performed an antegrade balloon angioplasty of his thrombosed femoral artery using a transvenous, transcardial approach via a ventricular septal defect. There were no complications. Doppler sonography showed no residual stenosis after 4 months.

A novel method for transcatheter closure of atrial septal defect within an aneurysm of the fossa ovalis: double sheath technique.

An aneurysm of the fossa ovalis is frequently associated with an atrial septal defect. Intervention with transcatheter closure of such defects may be difficult since it bears the risk of inadvertent deployment of the device with both umbrellas in the right or left atrium. A novel technique for the closure of such multiperforated aneurysms of the fossa ovalis, which allows central positioning and controlled deployment of the device, is reported.

[Infantile hemangioendothelioma of the liver--sonographic diagnosis and follow-up]. / Das infantile Hämangioendotheliom der Leber - sonographische Diagnostik und Verlaufskontrolle.

OBJECTIVE: Hepatic haemangioendothelioma is the most frequently observed hepatic tumour of early infancy. Lesions may cause life-threatening disease due to av-shunt-related cardiac failure, Kasabach-Merritt syndrome or encroachment on surrounding tissue. In this paper, the value of ultrasonography at initial work-up as well as during follow-up under various management strategies is discussed. METHOD: Retrospective analysis of sonographic and clinical data as well as outcome of 14 patients. RESULTS: The tumours may present initially with a typical sonographic pattern of a roundish solitary lesion consisting predominantly of massively perfused, tortuous cavities. In these cases, histological verification of the diagnosis is not mandatory, provided serological tumour markers are negative. Multifocal haemangioendotheliomata with a solid appearance, however, cannot be reliably distinguished from other entities sonographically. Tumour development - with or without therapy - can be followed up precisely using repeated ultrasound evaluations of tumour volume and sono-morphology as well as Doppler examination of tumour perfusion. CONCLUSIONS: Guidelines for the management of these patients are discussed, based on our experience and a review of the literature. Sonography proves to be of outstanding importance.

Transcatheter recanalization of the left main pulmonary artery after four years of complete occlusion.

A technique for transcatheter "reconstruction" of a completely occluded left pulmonary artery using radiofrequency perforation with subsequent balloon dilation and stent implantation is reported in a 7-year-old child. It is shown that transcatheter radiofrequency perforation can still be effective years after the occlusion of a vessel.

Transcatheter retrieval and repositioning of an Amplatzer device embolized into the left atrium.

A transcatheter technique is described for stabilization and retrieval of an embolized Amplatzer device, which was inadvertently deployed in the left atrium of a 2-year-old girl with hemodynamically significant atrial septal defect within the fossa ovalis. Since surgery was not available for immediate device retrieval, transcatheter means were chosen to prevent embolization of the device into the mitral valve. After stabilizing the device by creating a guidewire circuit through the wire mesh of the right atrial disk, the Amplatzer device was repositioned through the interatrial defect by snaring the microscrew. No residual shunting and perfect device position was recorded during Doppler echocardiography directly after the procedure as well as 1, 2, and 120 days after the intervention. Cathet. Cardiovasc. Intervent. 51:297-300, 2000.

[Transcatheter closure of atrial septal defects with the CardioSEAL occluder]. / Katheterinterventioneller Verschluss von Vorhofseptum-Defekten mit dem CardioSEAL-Okkluder.

Data on mid- and long-term follow-up for the recent devices for closure of secundum-type atrial septal defects are limited. The purpose of our retrospective study was to report the effectiveness of transcatheter closure in patients with various morphological types of atrial septal defect other than centrally located defects within the oval fossa using the CardioSEAL and CardioSEAL-Starflex occluder. A total of 91 patients (age 1.5-71 years, median 6 years) underwent transcatheter closure. On the transesophageal echocardiogram, defect size varied from 6 to 18 mm with an estimated stretched diameter of 11 to 24 mm, median 15 mm; the ratio of the stretched diameter to septal length ranged from 0.28 to 0.68. Mean follow-up was 28.7 +/- 11,9 months (range 3-46 months). Isolated secundum-type defects were present in 59 patients (65%), multiple septal defects including patients with perforated atrial septal aneurysms and defects with deficient atrial rim in 32 patients (35%). Occlusion rate using device diameters from 23 to 40 mm increased from 66% (60/91 patients) immediately after implantation to 86% (48/56 patients) 24 months after implantation. Patients with isolated secundum-type defects presented with a significantly higher primary closure rate (45/59 patients, 76%) compared to patients with various defect morphology. Closure rate did not depend on the type of implanted device modification. No thrombus formation, sustained atrial arrhythmia or infective endocarditis occurred. Serial transthoracic echocardiographic findings revealed protrusion of one left-sided arm onto the right atrial aspect in 5 patients; malposition of one right-sided superior arm of the device was observed in 7 patients. Fluoroscopy showed single fatigue fracture in 7 patients (7.7%) within the first 6 months after implantation. These results demonstrate that transcatheter closure with the double umbrella device was effective and safe on medium-term follow-up and could be extended to atrial septal defects of various morphology.

Transcatheter PFO closure with a prominent Eustachian valve.

We report the successful PFO closure in a 57-year old woman with complex atrial anatomy. To avoid the risk of interfering with the occluder device due to a prominent Eustachian valve, a Helex Septal Occluder was implanted. Differential therapeutic considerations and specific device characteristics are outlined.

[Early postoperative dysfunction of a modified Blalock-Taussig shunt: successful therapy with angioplasty and stent implantation in the subclavian artery]. / Frühe postoperative Dysfunktion eines modifizierten Blalock-Taussig-Shunts: Erfolgreiche Therapie mit Angioplastie und Stentimplantation in die Arteria subclavia.

A newborn with pulmonary atresia with ventricular septal defect and transposition of the great arteries was palliated with a modified Blalock-Taussig shunt at 5 days of age. Three days postoperatively arterial oxygen saturations dropped significantly. Thrombosis of the shunt was suspected. Angiography revealed stenosis of the proximal subclavian artery related to the creation of the shunt. The patient was successfully treated with angioplasty and stent implantation into the stenotic subclavian artery. Follow-up angiography 3 months after stent deployment showed a completely patent subclavian artery and unobstructed blood flow across the modified Blalock-Taussig shunt.

Transcatheter recanalization and subsequent stent implantation for the treatment of early postoperative thrombosis of modified Blalock-Taussig shunts in two children.

Two babies with duct-dependent cyanotic congenital heart disease were palliated with modified Blalock-Taussig shunts. One patient was diagnosed to have tetralogy of Fallot, and the other patient, tricuspid atresia type Ia. Early postoperative arterial oxygen saturations dropped significantly due to shunt thrombosis. Both patients were successfully treated with angioplasty and stent implantation.

[Interventional therapy for hemangioendothelioma of the liver in a newborn infant using a central venous approach]. / Interventionelle Therapie eines Hämangioendothelioms der Leber bei einem Neugeborenen über einen venösen Zugang.

We report on a newborn (birth weight 3600 g) with high-output cardiac failure due to a large hepatic hemangioendothelioma requiring mechanical ventilation. One day post-partum therapy with steroids, furosemide, and digitalis was initiated. Despite this, the clinical condition deteriorated. Therefore, selective coil-embolization of the arterial vessels supplying the hemangioendothelioma was performed using a venous approach with passage to the arterial side via the ductus arteriosus. After the embolization the patient improved quickly and he was extubated 4 days postinterventionally. Follow-up sonography 4 months postinterventionally showed dramatic regression of the hepatic tumor. We conclude that the coil-occlusion of hepatic hemangioendothelioma should be performed early in symptomatic newborns as arterial puncture and its associated complications can be avoided by using a venous approach with passage to the arterial side via the ductus arteriosus. In addition, in this age group, access to the portal system can be gained through the umbilical vein to occlude portal venous supplies to the hepatic hemangioendothelioma.

Radiofrequency current application on immature porcine atrial myocardium: no evidence of areas of slow conduction after 12-month follow-up.

INTRODUCTION: Radiofrequency current (RFC) application is a widely used procedure for treatment of supraventricular arrhythmias. The purpose of this study was to investigate late electrophysiologic sequelae of RFC lesions at immature atrial myocardium in pigs, as they have not yet been systematically investigated in vitro. METHODS AND RESULTS: RFC application (temperature guided) was performed in seven piglets (mean age 6 weeks) by a steerable 6-French electrode catheter positioned at the lateral aspect of the tricuspid valve annulus. After 12 months, hearts were removed, and lesions with surrounding tissue were isolated. The viable tissue at the border of the specimen was paced with a cycle length of 500 and 600 msec. One hundred fifty impalements were performed on each specimen using capillary microelectrodes to record action potential characteristics from the lesion's surface and the surrounding tissue. In all seven specimens, no transmembrane action potentials from the fibrotic surface of each of the lesions could be recorded. The surrounding viable tissue was sharply demarcated electrically. No areas of slow conduction were detected. Action potential characteristics as mean maximum diastolic transmembrane potential, mean action potential duration at 90% repolarization, and upstroke velocity of phase 0 of the action potential were all normal. CONCLUSION: No evidence of areas of slow conduction 12 months after RFC application at immature atrial myocardium suggests that this technique is safe regarding occurrence of late atrial tachyarrhythmias after the procedure.

[Mechanical recanalization of venous thrombosis and pulmonary embolism with the Clotbuster thrombectomy system in a 12-year-old boy]. / Mechanische Rekanalisation einer Venenthrombose und Lungenembolie mit dem Clotbuster-Thrombektomie-System bei einem 12 Jahre alten Jungen.

The treatment of patients with deep vein thrombosis and pulmonary embolism with contraindications for a thrombolytic therapy is a therapeutic challenge. We report on a 12 year old patient who was treated for large cell lymphoma according to NHL-BFM 95: Block AA protocol. During his therapy, he developed a thrombosis of his right femoral vein and pulmonary embolism affecting the left segments 4, 5, 8, and 9. Because of cerebral metastasis a fibrinolytic therapy was contraindicated. Therefore, we performed a mechanical thrombectomy using the Amplatz thrombectomy device. The postinterventional scintigraphy showed a markedly improved pulmonary perfusion; dopplersonography 4 months postinterventionally showed a patent right femoral vein.

Transcatheter closure of various types of defects within the oval fossa using the double umbrella device (CardioSEAL)--feasibility and echocardiographic follow-up.

Data on long-term follow-up for closure of so-called secundum type" atrial septal defects within the oval fossa using recently developed devices are limited, and results focused on presence of residual shunting. The purpose of our study was to report the experience from a single center establishing the effectiveness of transcatheter closure in patients with various types of defect other than those located centrally within the oval fossa. A total of 72 patients was included in this study. On transesophageal echocardiography, the size of the defects varied from 6 to 18 mm, with estimation of the stretched diameter from 11 to 21 mm. The ratio of stretched diameter to the extent of the residual septum ranged from 0.28 to 0.54. Mean follow-up was 30.5+7.4 months, with a range from 13 to 42 months. The rate of closure using devices with diameters from 28 to 40 mm increased from 80% immediately after implantation to 93% in the 57 patients examined 24 months after implantation. For further analysis, we compared the 44 patients with a solitary, centrally located, defect to 28 having morphological variations, including superiorly located defects with deficient superior and aortic rims, multifenestrated and aneurysmal defects, or isolated additional defects. There was no incidence of formation of thrombus, sustained atrial arrhythmia, or infective endocarditis. Residual shunting was not influenced by location or morphology of the defects, but increased with size, stretched diameter, and the ratio of pulmonary to systemic flows. Serial transthoracic echocardiographic findings revealed malposition of one right-sided superior arm of the device in 8 patients, while protrusion of one left-sided arm onto the right atrial aspect was observed in 3 patients. Fluoroscopy showed fatigue fracture of a single arm in 7 patients (9.7%) within the first 6 months after implantation. These results demonstrate that transcatheter closure with the non self-centering double umbrella device was effective and safe on medium-term follow-up, and could be extended to defects within the oval fossa having various morphologies. Residual shunting resolved with time, and was not related to either morphology or the position of the device.