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Philipp Bonhoeffer

Publications and source records attributed to Philipp Bonhoeffer.

33 records · Page 2Linked to original sources
PubMed2004

Is percutaneous implantation of a bovine venous valve in the inferior vena cava a reliable technique to treat chronic venous insufficiency syndrome?

BACKGROUND: To evaluate the feasibility and safety of percutaneous implantation of a balloon-expandable valved stent in the inferior vena cava. MATERIAL/METHODS: A valve harvested from a bovine jugular vein, preserved in glutaraldehyde and mounted in a stent, was evaluated in animals. Six lambs, weighing 30 to 40 kg, were included in the study. Under general anesthesia, a valved stent with its 18-Fr delivery system was inserted through the right jugular vein, advanced, and delivered in the inferior vena cava. Hemodynamic and angiographic evaluations were performed prior to, immediately after, and two months after implantation. RESULTS: All valved stents were successfully implanted in the desired position. No early or late migration of the stent was noted in any animal. All valves were perfectly competent at the time of implantation. At 2 months, none of the valves were functional. The inferior vena cava was occluded at the site of valve insertion and collateral circulation was present in all animals. At autopsy, the valved stent was completely occluded. CONCLUSIONS: Valve implantation is feasible in the venous system through a percutaneous approach. The function of this valve in that position is limited by the absence of a high pressure gradient. Animal models and improvements in the device are mandatory before considering this technique as a reliable procedure to treat chronic venous insufficiency syndrome in humans.

Angiography↗
PubMed2004

Nonsurgical pulmonary valve replacement: why, when, and how?

Percutaneous transcatheter interventions for valve replacement or implantation is one of the most exciting developments in the field of interventional cardiology. Valvular stenosis has been treated by balloon dilatation with early and late results; however, treatment for valvular regurgitation has remained surgical until now. Most new designs have been investigated for implantation of valves in the left or right ventricular outflow tracts. Patients with surgery on the right ventricular outflow tract for congenital heart disease constitute the most common group for reoperations during late follow-up. Surgical pulmonary valve replacement can be performed with low mortality; however, it sets up a substrate for future operations. Also, the risk of cardiopulmonary bypass, infection, bleeding, and ventricular dysfunction remains. A transcatheter technique is likely to have more acceptance and may expand the indications for early intervention for right ventricular outflow tract dysfunction.

Heart Defects, Congenital↗
PubMed2004

Percutaneous valve replacement: current state and future prospects.

Percutaneous valve implantation is the development of a foldable heart valve that can be mounted on an expandable stent delivered percutaneously through standard catheter-based techniques and implanted within a diseased valve annulus. In cases with severe aortic stenosis, the diseased valve has to be pre-dilated. To perform a true replacement the diseased valve has to be ablated and removed. In this article, we review the development of percutaneous valve replacement technology and discuss future prospects in this field.

Forecasting↗
PubMed2003

Perforation of the atretic pulmonary valve. Long-term follow-up.

OBJECTIVES: We evaluated the long-term results of perforation of the pulmonary valve in patients with pulmonary atresia with an intact ventricular septum (PA-IVS). BACKGROUND: Interventional perforation of the pulmonary valve is considered the elective first stage treatment for PA-IVS, particularly in patients with a tripartite right ventricle (RV) and normal coronary circulation. However, the long-term results of this procedure are lacking. METHODS: Between January 1991 and December 2001, 39 newborns with a favorable form of PA-IVS underwent attempted perforation of the pulmonary valve. We evaluated the early and long-term outcomes. RESULTS: Median tricuspid and pulmonary z values were -1.2 and -2.4, respectively. Perforation was successful in 33 patients. Among them, 17 needed neonatal surgery, 13 did not need any surgery, and 3 had elective surgery after the first month of life. There were two procedure-related deaths, seven nonfatal procedural complications, and four postsurgical deaths. Compared with patients needing neonatal surgery, those having no or elective surgery had a higher incidence of a tripartite RV and a higher median tricuspid z value (92% vs. 53%, p = 0.04 and -1.7 vs. -0.5, p = 0.03). At a median follow-up of 5.5 years (range 0.5 to 11.5), survival was 85% and freedom from surgery was 35%. Five patients, four of whom had neonatal surgery, underwent a partial cavo-pulmonary connection. CONCLUSIONS: Our results show that this technique, although burdened by non-negligible mortality and morbidity, is effective in selected patients with a normal-sized RV. Preselection of patients allows interventional or surgical biventricular correction in the majority of cases.

Cardiac Catheterization↗
PubMed2003

Unusual interventional management in an adult with tetralogy of Fallot.

A 53-year-old man with tetralogy of Fallot had been palliated with two classic Blalock-Taussig shunts. Cardiac catheterization in our center revealed acquired atresia of the pulmonary valve. We perforated and dilated the valve as a palliative procedure with a new system using radiofrequency energy.

Catheter Ablation↗
PubMed2003

Transcatheter reconstruction of the right heart.

We report the interventional procedures performed on a 12-year-old child with obstruction of the right ventricular outflow tract, pulmonary valvar insufficiency, pulmonary arterial stenosis, and an atrial septal defect. A staged repair of all anomalies was performed successfully using transcatheter techniques.

Cardiac Catheterization↗
PubMed2002

Percutaneous insertion of the pulmonary valve.

OBJECTIVES: We report our experience of percutaneous valve insertion in pulmonary position in humans. BACKGROUND: Over the past 40 years, prosthetic conduits have been developed to surgically establish continuity between the right ventricle and the pulmonary artery. However, stenosis and insufficiency of the conduit due to valvular degeneration or panus ingrowth frequently occur, limiting patients' lifespan. Percutaneous stenting of conduits has recently emerged as a technique for delaying surgical replacement, but it creates a pulmonary regurgitation when crossing the valve. METHODS: Seven children and one adult with stenosis and/or insufficiency of the pulmonary graft underwent percutaneous implantation of a bovine jugular valve in pulmonary position. RESULTS: Percutaneous pulmonary valve (PV) replacement was successful in all patients. No complications occurred in early follow-up. Angiography, hemodynamic studies and echocardiography after the procedure showed no significant regurgitation of the implanted valve. Implantation was effective in relieving the obstruction in five patients. All patients showed improvement in their clinical status at the latest follow-up (mean 10.1 months). CONCLUSIONS: Non-surgical insertion of the PV is possible without any major complications. This new technique may have an important role in the management of conduit obstructions and pulmonary regurgitation.

Adolescent↗
PubMed2002

Steps toward percutaneous aortic valve replacement.

BACKGROUND: To date, the surgical approach is the only option to replace the aortic valve. Percutaneous pulmonary valve replacement has recently opened new perspectives on transcatheter replacement of cardiac valves. We report our experience of aortic valve replacement through a percutaneous technique in lambs. METHODS AND RESULTS: A bovine jugular vein containing a valve was dissected and sutured into a stent. Twelve lambs were divided into 3 groups. In the first, a valved stent was implanted in the descending aorta after creation of an aortic insufficiency. In the second, the valve was implanted in the native position. In the third, we inserted a valved stent in the native position using an orientation mechanism. All valves were successfully delivered and functioned perfectly in short-term evaluation. All experiments in group 2 failed: 1 valve obstructed the coronary artery orifices, 1 stent was responsible for a major mitral valve insufficiency, and the third implant migrated prematurely. A paraprosthetic leak occurred in the last animal in this group. Animals in group 3 had successful implantation of the valved stent. The orientation mechanism allowed perfect alignment of the device without any damage to the coronary circulation or to mitral valve function. CONCLUSIONS: Nonsurgical implantation of an aortic valve is possible in lambs in the descending aorta and in the native position. An orientation mechanism is obviously needed to avoid obstruction of the coronary orifices. With further improvements, this technique should be feasible in humans.

Animals↗
PubMed2002

Age-related aspects of balloon angioplasty for postsurgical aortic recoarctation.

Balloon angioplasty is now the elective technique for relief of aortic recoarctation, since it has low mortality, low morbidity, and good results at follow-up. Some concern exists concerning the possible increased risk in young children. To investigate such age-related aspects, we examined 58 children undergoing consecutive balloon angioplasty for postsurgical recoarctation. Of the children, 30 were younger and 28 older than 1 year. Recoarctation was more frequent with ventricular septal defect or other cardiac anomalies (p < 0.001). Systolic hypertension was present in 70% of children aged less than 1 year, but in only 32% of those older than 1 year (p < 0.001). The initial gradient was inversely related with the age at dilation (r = -0.28, p < 0.05), and correlated with systolic blood pressure (r = 0.81, p < 0.01). The procedure was successful in 87% of children older than, and 86% of those under 1 year. Age was not related with residual gradient, nor with the percentage increase of diameter of the site of stenosis. After balloon angioplasty, systolic hypertension was still present in 37% of children younger than 1 year, and in 25% of those older than 1 year (p < 0.05). Three complications occurred in children younger than 1 year, and 6 in those older (p < 0.05). Our results show, first, that recoarctation occurs earlier in the setting of complex disease, second that children suffering recoarctation at a younger age are more likely to be hypertensive, either before or after balloon angioplasty, third, that balloon angioplasty has the same rate of success in children below or above the age of one year, although the procedure still carries a not negligible risk. Finally, the procedure does not carry a higher risk for those children below the age of 1 year.

Age Factors↗
PubMed2002

Transcatheter occlusion of a large aortoazygos fistula using the Amplatzer device.

This report describes the percutaneous embolization of an unusual aortoazygos arteriovenous fistula in a 22-month-old child. The large fistula (8 mm) was successfully occluded using a 12- to 10-mm Amplatzer Duct Occluder device using the arterial approach. The device was incompletely deployed into the abnormal vessel to avoid tearing of the intima by the sharp distal disk.

Aortic Diseases↗
PubMed2002

Transhepatic closure of a post-fontan hepatic veins to left atrium fenestration in visceral heterotaxia and dextrocardia.

This article reports on the transhepatic closure of post-Fontan hepatic veins to left atrium fenestration in a 13-year-old girl with left atrial isomerism, dextrocardia, azygos continuation to the left superior vena cava, and median liver. The transhepatic route seemed to be the less tortuous access to the fenestration which was previously partially occluded with a CardioSeal device. The hepatic veins were entered at the left abdominal side using fluoroscopic guidance and the fenestration was uneventfully occluded with an Amplatzer septal occluder device.

Adolescent↗
PubMed2002

Percutaneous implantation of a biological valve in the aorta to treat aortic valve insufficiency -- a sheep study.

BACKGROUND: Historically, the surgical implantation of a mechanical valve in the descending aorta permitted the reduction of regurgitant flow in chronic aortic insufficiency. Long term clinical results were excellent but with the development of the pump oxygenators, orthotopic valvar replacement has become the conventional treatment of aortic valve diseases. We wanted to reconsider the ectopic position in sheep using a new percutaneous technique. MATERIAL/METHODS: A biological valve harvested from a bovine jugular vein was sutured into a vascular stent. After the creation of a severe aortic insufficiency, the valved stent was percutaneously implanted according to standard stent placement techniques. Hemodynamic and angiographic evaluations were carried out during the procedure; finally, anatomic evaluation was performed. RESULTS: A severe aortic insufficiency was created in all animals (9/9). 3 had a single stent in the descending aorta and 3 had an additional stent in the brachiocephalic trunk. A control group of 3 animals had no valve implantation. One sheep had an additional valve implant because one overdilated stent had become insufficient. Early evaluation of the implanted valve function confirmed the perfect competence of 9 out of 10 valved stents. However, for unknown reasons all the animals died within 24 hours after the procedure. CONCLUSIONS: Percutaneously implanted valves in the thoracic aorta of sheep with massive aortic insufficiency function well in the acute study. In comparison to previous surgical results, this technique might become an alternative to surgery in patients with chronic aortic insufficiency in whom perioperative risks are high.

Animals↗