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Biomedical subjects

M Peuster

Publications and source records attributed to M Peuster.

At least 19 recordsLinked to original sources

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.

Atrial Appendage↗

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.

Cardiac Catheterization↗

[Transcatheter closure of atrial septal defects with the CardioSEAL occluder].

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.

Adolescent↗

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.

Atrioventricular Node↗

[A new combined surgical interventional method for univentricular palliation of congenital heart defects].

UNLABELLED: Total cavo-pulmonary anastomosis is frequently performed to palliate patients with a broad variety of congenital heart defects with functionally univentricular hearts precluding biventricular circulation. In patients with risk factors for primary repair a stepwise approach is frequently chosen with initial creation of an aorto-pulmonary shunt followed by a Glenn anastomosis or hemifontan procedure. Finally a total cavo-pulmonary connection is completed surgically. The aim of this feasibility study was to develop a combined surgical-interventional approach for creation of a total cavo-pulmonary anastomosis which reduces the number of surgical interventions, precludes extracorporeal circulation and intracardiac sutures, putting the patients at risk for subsequent rhythm disturbances. METHODS: A Glenn anastomosis was created in 10 sheep without cardio-pulmonary bypass. The superior vena cava was banded superior to the cavo-atrial junction leaving a minimal lumen for subsequent interventional balloon dilatation and implantation of a stent graft. A 15 mm Gore-Tex tube was sutured around the inferior vena cava intrapericardially to provide resistance for subsequent interventional stent implantation. Total cavo-pulmonary anastomosis was completed interventionally by dilating the banded vena cava superior and connection of the inferior vena cava to the superior vena cava by implanting an Aneurx covered stent graft. RESULTS: All animals survived the combined surgical-interventional procedure. Stent deployment was possible without causing obstruction to the hepatic veins. Neither stent dislocation nor rhythm disturbances were encountered. CONCLUSIONS: Total cavo-pulmonary anastomosis can be achieved without intracardiac sutures and cardio-pulmonary bypass by use of a combined surgical-interventional approach using the Aneurx covered stent graft.

Animals↗

Abbreviated combined anatomical/electrophysiological approach for catheter ablation of atrioventricular nodal reentrant tachycardia in children.

Atrioventricular nodal reentrant tachycardia was proven during electrophysiologic study in 41 children, aged from 3.7 to 16 years, who were referred for catheter ablation of symptomatic supraventricular tachycardia. Using an abbreviated combined anatomical and electrogram-guided approach for selective ablation of the slow pathway, a steerable ablation catheter was placed at the inferior region of the vestibule of the tricuspid valve close to the orifice of the coronary sinus, with the intention of recording a multicomponent local atrial electrogramm during sinus rhythm. If application of radiofrequency current of 500 kHz at 70 degrees C at this site did not result in a slowly accelerated junctional rhythm, at a rate of less than 120 beats per minute, the catheter was stepwise advanced up to a position midway towards the apex of the triangle of Koch for additional applications of energy. Ablation was achieved in 35 of the patients. In 6 patients, the slow pathway was modulated such that the tachycardia could no longer be induced. The number of applications of energy ranged from 1 to 19, with a median of 6 applications. The mean period of fluoroscopy was reduced to 15.6 (4.3 to 39.8) minutes, while the overall duration of the catheterization procedures ranged from 88 to 280 (mean 173.2) minutes. In none of the patients did we observe permanent high grade atrioventricular block. During follow-up over a mean of 4.1 years, two patients had recurrence of tachycardia, corresponding to a 95% rate of success in the midterm. We conclude that selective radiofrequency ablation of the slow pathway using the abbreviated anatomical and electrophysiological approach is a safe and curative therapeutic approach in children with atrioventricular nodal reentrant tachycardia. Periods required for fluoroscopy can be significantly reduced, and mid-term results are excellent.

Adolescent↗

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.

Adolescent↗

[Infantile hemangioendothelioma of the liver--sonographic diagnosis and follow-up].

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.

Female↗

A novel approach to temporary stenting: degradable cardiovascular stents produced from corrodible metal-results 6-18 months after implantation into New Zealand white rabbits.

OBJECTIVE: To determine whether corrodible materials may be safely used as biodegradable cardiovascular implants. DESIGN: Corrodible iron stents (> 99.8% iron) were produced from pure iron and laser cut with a stent design similar to a commercially available permanent stent (PUVA-AS16). A total of 16 NOR-I stents were implanted into the native descending aorta of 16 New Zealand white rabbits (mean luminal diameter at the implantation site 3.4 mm, balloon diameter to vessel diameter ratio 1.13). RESULTS: No thromboembolic complications and no adverse events occurred during the follow up of 6-18 months. All stents were patent at repeat angiography after 6 (n = 9), 12 (n = 5), and 18 months (n = 2) with no significant neointimal proliferation, no pronounced inflammatory response, and no systemic toxicity. CONCLUSIONS: This initial in vivo experience suggests that degradable iron stents can be safely implanted without significant obstruction of the stented vessel caused by inflammation, neointimal proliferation, or thrombotic events.

Absorbable Implants↗

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.

Cardiac Catheterization↗

[Early postoperative dysfunction of a modified Blalock-Taussig shunt: successful therapy with angioplasty and stent implantation in the subclavian artery].

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.

Angiography↗

[Antegrade flow in the aorta ascendens despite aortic atresia: 2 case reports with retrograde coronary perfusion through coronary fistulas and sinusoids].

In aortic atresia, coronary perfusion normally occurs through retrograde blood flow in the ascending aorta. We report on two patients with antegrade flow in the ascending aorta despite aortic atresia. In one patient with hypoplastic left heart syndrome (aortic atresia, severe mitral stenosis), an intact interatrial septum/premature closure of the foramen ovale was found. While no other way of left atrial or ventricular decompression was found, echocardiography, angiography and the post-mortem examination showed left ventricular to coronary sinusoids as the sole pathway for systemic oxygenation. In a second patient with complex congenital heart disease, including aortic atresia, antegrade flow in the ascending aorta was through a left coronary fistula with shunt flow originating from the pulmonary trunk. This report describes systemic perfusion depending on retrograde coronary flow due to coronary-cameral (sinusoids) and coronary arterio-venous fistulas leading to the phenomenon of antegrade blood flow in the ascending aorta despite aortic atresia.

Aorta↗

[Atrioventricular nodal reentry tachycardia in children: curative treatment by high frequency catheter ablation].

BACKGROUND: Atrioventricular nodal reentrant tachycardia (AVNRT) is one of the most common forms of supraventricular tachycardia in the pediatric population. PATIENTS AND METHODS: 41 children with a mean age of 9.6 (3.7-16) years with recurrent atrioventricular nodal reentrant tachycardia (AVNRT) refractory to medical treatment (n = 38) and recurrent syncope (n = 3) underwent electrophysiologic (EP) study. In all patients dual AV-nodal physiology could be demonstrated during EP study and typical form of AVNRT (mean heart rate 220/min) could be induced by programmed atrial stimulation. A steerable 7 F ablation catheter was placed at the inferoparaseptal region of the tricuspid valve annulus close to the orifice of the coronary sinus with the intention to record a late fractionated local atrial electrogram during sinus rhythm. Starting at this point radiofrequency current (500 kHz) with a target temperature of 70 degrees C was delivered with the intention to ablate the slow pathway. If a slowly accelerated junctional rhythm (< 120/min) occurred during energy discharge, programmed atrial stimulation was repeated. Otherwise radiofrequency current was delivered step by step up to a septal position next to the tricuspid valve annulus. Slow pathway ablation was defined as lack of evidence of dual AV nodal pathways during repeated atrial stimulation. Slow pathway modulation was defined as maximal one atrial echoimpulse after ablation. RESULTS: The number of energy applications ranged from 1-19 (median 6). In 35/41 patients slow pathway ablation could be achieved; in six patients the slow pathway was modulated. In none of the patients permanent high grade AV block was observed. During follow-up (mean 4.1 years) two patients had a recurrent episode of AVNRT after slow pathway modulation. All other patients are still free of AVNRT without medical treatment. CONCLUSION: Selective radiofrequency current ablation/modulation of the slow pathway is a safe and curative treatment of AVNRT in young patients.

Adolescent↗

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.

Aortic Valve Stenosis↗