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Biomedical subjects

W E Hellenbrand

Publications and source records attributed to W E Hellenbrand.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of the AMPLATZER vascular plug for embolization of peripheral vascular malformations associated with congenital heart disease.

OBJECTIVE: The purpose of this study is to evaluate the recently FDA-approved AMPLATZER Vascular Plug in the embolization of vascular lesions associated with congenital heart disease (CHD). BACKGROUND: Fistulas and arteriovenous malformations have been occluded using various devices. The AMPLATZER Vascular Plug is a self-expandable, cylindrical device, used for embolization in the peripheral vasculature. METHODS: A total of 84 vessels in 52 patients with CHD from 11 centers were occluded with 89 AMPLATZER Vascular Plugs, delivered through a coronary guide catheter in various vascular sites, including collaterals, pulmonary arterio-venous and coronary artery fistulas, transhepatic tracts, central shunts, patent ductus arteriosus (PDA), and excluded hepatic vein. Complete vessel occlusion was demonstrated within 10 min in 94% of patients. RESULTS: There was no device embolization, vascular disruption, or procedure-related complication. One vascular plug implanted in a large type C PDA required surgical removal followed by PDA ligation, after 5 weeks from successful implant because of significant residual flow through the device. CONCLUSIONS: The AMPLATZER Vascular Plug is an effective transcatheter occlusion device in the embolization of a wide variety of vascular lesions associated with CHD. Based on our early experience, caution should be used when considering the Vascular Plug as a closure device for large PDA.

Adolescent↗
PubMed2001

Endovascular stents for coarctation of the aorta: initial results and intermediate-term follow-up.

OBJECTIVES: The aim of this study was to evaluate the use of endovascular stents in native and recurrent coarctation of the aorta (CoA). BACKGROUND: Stents have been used successfully in various locations. Their use in CoA can be an alternative to surgery or balloon angioplasty (BA). METHODS: Thirty-four patients with CoA (13 native and 21 re-coarctation after surgery or BA) with a mean age of 16 +/- 8 years (range 4 to 36 years) underwent attempted stent implantation between 1993 and 1999. Successful outcome was defined as peak systolic pressure gradient after stent implantation < 20 mm Hg. RESULTS: Stents were implanted in 33/34 patients, and successful outcome occurred in 32/33 patients. Peak systolic pressure gradient decreased from 32 +/- 12 mm Hg to 4 +/- 11 mm Hg (p < 0.001). Coarctation site to descending aorta diameter ratio increased from 0.46 +/- 0.16 to 0.92 +/- 0.16 (p < 0.001). Two patients underwent successful stent re-dilation 16 and 21 months after initial implantation. Six patients (18%) developed complications, including two patients who underwent surgery. Follow-up for 29 +/- 17 months (range: 5 to 81 months) demonstrated no evidence of re-coarctation, aneurysm formation, stent displacement or fracture. Systolic blood pressure (SBP) decreased from 136 +/- 21 mm Hg before stent placement to 122 +/- 19 mm Hg at follow-up (p = 0.002). The SBP gradient decreased from 39 +/- 18 mm Hg to 4 +/- 6 mm Hg, and peak Doppler gradient decreased from 51 +/- 26 mm Hg to 13 +/- 11 mm Hg at follow-up (p < 0.001). CONCLUSIONS: Intravascular stent placement for native and recurrent CoA has excellent results in the short and intermediate terms. Long-term outcome remains to be evaluated.

Adolescent↗
PubMed2000

Pulmonary thrombosis, homocysteinemia, and reperfusion edema in an adolescent.

Deep vein thrombosis, pulmonary embolism, and pulmonary thrombosis in situ are rare in childhood and adolescence [1,2]. Unfortunately, these diagnoses may be unsuspected in a pediatric patient with dyspnea and chest pain. This article illustrates the diagnostic and therapeutic challenges that arose from unrecognized chronic thrombotic disease in an adolescent.

Adolescent↗
PubMed2000

Balloon angioplasty of postsurgical recoarctation in infants: the risk of restenosis and long-term follow-up.

OBJECTIVES: This study was undertaken to evaluate the long-term results of balloon angioplasty (BA) for postsurgical recoarctation in infants. BACKGROUND: Balloon angioplasty is a well-accepted modality for the treatment of recoarctation. However, infants remain a group of concern because of their size, risk for complications and the potential for restenosis with growth. Age <12 months has been determined to be a risk factor for the development of recoarctation after angioplasty for native coarctation. Although studies on postsurgical coarctation have found no relationship between age at angioplasty and the development of recoarctation, few studies specifically addressing infants have been performed. METHODS: Clinical, echocardiographic, hemodynamic and angiographic data on 22 consecutive children <1 year of age who underwent BA between 1986 and 1996 were reviewed. RESULTS: A successful result, defined as a postprocedure gradient of < or =20 mm Hg, was achieved in 20 of 22 (91%) infants with a reduction in the systolic peak pressure gradient from 48 +/- 27 to 9 +/- 10 mm Hg (p < 0.001) and an increase in coarctation diameter from 2.7 +/- 1.1 to 5.2 +/- 1.5 mm (p < 0.001). At long-term follow-up of a median of 56 months (0.6 to 12 years), the restenosis rate after an initial optimal result was 16% (3 of 19). Five (24%) infants required reintervention (2 initially unsuccessful; 3 recoarctation), with a success rate of 95% after two procedures. Suboptimal long-term outcome correlated with a lower infant weight. CONCLUSIONS: Balloon angioplasty can be safely performed in infants, with good long-term results. The risk of restenosis is low and can be successfully managed with repeat angioplasty.

Angioplasty, Balloon↗
PubMed1999

Recent advances in interventional pediatric cardiovascular disease.

Transcatheter therapy in children with congenital or acquired heart disease is a challenging, innovative, and constantly evolving field. In this article we review the various "nonsurgical" techniques that are currently available, with a discussion of their applications and an update on the recent advances in the field of interventional cardiology.

Angioplasty, Balloon↗
PubMed1998

Transcatheter closure of an anomalous venous connection by a novel method.

Left superior vena cavae draining to the left atrium have traditionally been treated with surgical ligation. Advances in cardiac catheterization have made transcatheter closure a viable alternative to surgery. We report on an innovative method using a Greenfield filter and Gianturco coils for closure of a persistent left superior vena cava.

Abnormalities, Multiple↗
PubMed1998

Recent advances in interventional pediatric cardiovascular disease.

Transcatheter therapy in children with congenital or acquired heart disease is a challenging, innovative, and constantly evolving field. In this article we review the various "nonsurgical" techniques that are currently available, with a discussion of their applications and an update on the recent advances in the field of interventional cardiology.

Angioplasty, Balloon, Coronary↗
PubMed1996

Implantation of balloon-expandable stents for coarctation of the aorta: implantation data and short-term results.

We report the immediate results and the short-term follow-up in a group of selected patients with coarctation of the aorta who underwent endovascular stent implantation. Balloon-expandable stents were implanted in 6 patients (mean age 19.8 +/- 5.1 years) with coarctation of the aorta (4 recurrent and 2 native) who underwent a total of 7 procedures (6 implantation and 1 further expansion). The systolic peak pressure gradient was decreased from 36.7 +/- 16.9 to 13.3 +/- 23.2 mm Hg (P < 0.005). There was a 66% increase in the mean coarctation diameter from 9.3 +/- 1.7 to 15.6 +/- 3.1 mm (P = 0.001) with the ratio of the coarctation to descending aorta diameter, measured at the level of the diaphragm, increasing from 0.49 +/- 0.1 to 0.81 +/- 0.2 (P < 0.005). The dilatation was successful in expanding the stent to an acceptable diameter in 5 of 6 patients. One patient underwent successful further expansion of a stent implanted 22 months previously. There were no immediate complications during balloon expansion and stent implantation. One patient suffered a femoral arterial bleed requiring surgical repair. There was one unrelated death. All patients were hypertensive (systolic blood pressure > 140 mm Hg) prior to stent implantation. At mean follow-up of 8 months, 3 patients are normotensive. There was no recurrence of coarctation, aortic dissection, or aneurysm formation in the patients in whom stent implantation was successful. These findings indicate that balloon-expandable stent implantation for coarctation of the aorta in selected patients is a safe and effective alternative approach for relieving the obstruction with a low complication rate and no recoarctation at short-term follow-up.

Adolescent↗
PubMed1996

Transcatheter closure of the patent ductus arteriosus: a comparative study between occluding coils and the Rashkind umbrella device.

This study was performed to evaluate the efficacy of transcatheter coil closure of the patent ductus arteriosus in comparison to our experience with the Rashkind umbrella device. Transcatheter coil closure of the patent ductus arteriosus has been reported with encouraging results. We present our experience with ducti up to 5.0 mm in diameter and report the short-term follow-up. We compare the results with our previous experience with the Rashkind umbrella device. Seventy-one patients underwent transcatheter coil closure. Median age was 3.1 years, and median weight was 13.6 kg. Mean ductus diameter was 2.0 +/- 1.1 mm. These were compared with 105 patients who underwent transcatheter closure using a single Rashkind umbrella device. The median age was 3.2 years and the median weight was 14.0 kg. The mean ductus diameter for this group was 2.1 +/- 0.6 mm. The ductus murmur in the coil group disappeared in all patients. Immediate (< or = 24h), complete closure was achieved in 89% of the coil group as compared to 71% for the Rashkind umbrella device group (P < 0.005). Closure rate for the coil group was 97% at the 6-month follow-up, vs. 82% for the Rashkind umbrella device group at the 6-12 month follow-up (P < 0.05). In almost all patients requiring more than one coil, the ductus was crossed serially from the aortic end. All patients with ductus diameter > or = 3.0 mm required two or more coils. Eleven coils in six patients embolized to the pulmonary arteries. All coils except one were retrieved with subsequent successful foil placement. Sixty-seven patients (94%) in the coil group were discharged in < or = 24 h. Transcatheter closure of the patent ductus arteriosus using multiple coils is a more effective technique than the Rashkind umbrella closure and has excellent short-term results. This can be performed safely as an outpatient procedure.

Adolescent↗
PubMed1995

Thromboembolic complications after Fontan operations.

BACKGROUND: Despite the increasing recognition of thromboembolic complications of the Fontan procedure, data characterizing such events are limited. The total cavopulmonary connection is believed to be less prone to this complication than other modifications of Fontan operations. We examined our experience with thromboembolism after Fontan operations to better characterize these events and their relation to the type of Fontan operation performed. METHODS AND RESULTS: We retrospectively identified 70 patients who underwent a Fontan operation between January 1978 and March 1994. Patients were divided into three groups: (1) total cavopulmonary connection, (2) atriopulmonary connection, and (3) conduit interposition. Fourteen patients (20%) developed a thromboembolic complication during a mean (+/- SD) follow-up of 5.2 +/- 4.7 years. The rate of thrombosis was similar in each group. The time from Fontan operation to thrombosis averaged 6.1 +/- 5.0 years. The overall rate of thromboembolic events was 3.9 per 100 patient-years. Twelve of the 14 thrombi were located within the venous circulation, 1 was in the left ventricle, and the location of 1 was undetermined. Six of the patients (43%) were asymptomatic, 3 (21%) presented with cerebrovascular events, and 5 (36%) presented with other symptoms. Thromboembolic events occurred from the perioperative period to 15 years after surgery. CONCLUSIONS: Thromboembolic complications occur frequently after the Fontan operation and its modifications and are a cause of significant morbidity. The time of presentation varies greatly. The rate of thrombosis appears to be similar in all modifications of the Fontan operation.

Adolescent↗
PubMed1992

Anomalous left coronary artery from the main pulmonary trunk: physiologic and clinical importance of its association with persistent ductus arteriosus.

Anomalous left coronary artery (ALCA) from the pulmonary trunk presents in early infancy with a clinical picture of failure to thrive, congestive heart failure (CHF), angina-like episodes, and mitral insufficiency. These manifestations which are due to myocardial ischemia may change in the presence of an associated lesion. We present a case and review two previous reports of a patent ductus arteriosus (PDA) associated with this anomaly. Although signs and symptoms are not as clear due to the less impaired coronary perfusion and the presence of a PDA, the presence of mitral insufficiency should raise the possibility of an anomalous coronary artery and, therefore, a cardiac catheterization and angiocardiography are recommended in anticipation of reparative surgery.

Aortography↗
PubMed1992

Hemodynamic evaluation before and after closure of fenestrated Fontan. An acute study of changes in oxygen delivery.

BACKGROUND: Acute changes in hemodynamics and oxygen delivery accompanying temporary occlusion of atrial defects in 14 patients after a fenestrated Fontan procedure were evaluated at a median interval of 32 days after surgery to identify candidates for permanent transcatheter closure of their defects. METHODS AND RESULTS: Patients ranged in age from 9 months to 33 years and in weight from 7.9 to 69 kg. Right atrial (RA), left atrial (LA), and aortic pressures, mixed venous (SmvO2) and aortic (SaO2) oxygen saturation, and whole-body oxygen consumption (VO2) were measured, and systemic blood flow (Qs), systemic oxygen transport (SOT), and oxygen extraction were calculated before and after occlusion. SmvO2, VO2, and RA pressures did not change, but SaO2 increased from 84 +/- 6% to 95 +/- 3% (p less than 0.05), and LA pressures fell from 5.1 +/- 3.6 to 3.7 +/- 2.2 mm Hg (p less than 0.05). Qs fell from 2.4 +/- 0.7 to 1.8 +/- 0.41.min-1.m-2 (p less than 0.05), SOT fell from 425 +/- 154 to 366 +/- 112 ml.O2.min-1.m-2 (p less than 0.05), and oxygen extraction increased from 0.40 +/- 0.12 to 0.46 +/- 0.13 (p less than 0.05). Only one patient did not undergo definitive closure of his defect because of a marked decrease in Qs and SOT with a significant rise in RA pressure. CONCLUSIONS: Although delayed closure of an atrial defect in these patients improved morbidity and mortality, the complete separation of the venous and systemic circulations was accomplished at the expense of decreased Qs and oxygen delivery despite the improved level of arterial oxygenation. The resting levels of oxygen extraction are elevated and will be associated with decreased exercise capability. The long-term benefits of closure of these fenestrations are yet to be shown.

Adolescent↗
PubMed1992

The right ventricle in congenital heart disease.

An increasing number of children with congenital heart disease are surviving into adulthood, creating new, unusual patients with different physiologic and anatomic problems for the adult cardiologist. This article discusses those lesions affecting primarily the right ventricle.

Heart Defects, Congenital↗