Use of endovascular stents to increase pulmonary blood flow in pulmonary atresia with ventricular septal defect.
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Child↗
Biomedical subjects
L N Benson
Publications and source records attributed to L N Benson.
Clinical impact of balloon angioplasty for branch pulmonary arterial stenosis.
The clinical impact of percutaneous balloon angioplasty on the management of patients with native or postoperative pulmonary arterial stenosis was reviewed. Seventy-four patients underwent 110 angioplasty procedures. Mean age at dilation was 6.7 +/- 5.3 years (range 0.2 to 18.1), 17 patients were aged less than 1 year, mean follow-up was 37.7 +/- 22.8 months (range 16 to 96), and 34 patients (44%) had follow-up angiography. Pulmonary artery dilation was acutely successful in 53% of patients, 17% had recurrent stenosis, and 5% had complications. The impact on subsequent care was favorably influenced in 26 of 74 patients (35%) with either complete resolution of stenosis (n = 7), optimizing future surgical conditions (n = 14), reduction in right ventricular pressure by greater than 20% (n = 3), or improvement of ipsilateral lung perfusion (n = 2). No patient previously considered inoperable was subsequently considered suitable for surgical repair owing to the intervention. No correlation was found between success and cardiac diagnosis (p = 0.48), site of stenosis (p = 0.78), balloon-vessel ratio (p = 0.42), or whether the stenotic area consisted of native or synthetic material (p = 0.22). No predictive factors for success could be defined, and often there was only a transient clinical impact. Due to the low complication risk and potential for a beneficial result, it still appears prudent to offer angioplasty as an initial therapeutic modality in this setting.
Adolescent↗
Intravascular stent prosthesis for right ventricular outflow obstruction.
OBJECTIVES: This study was designed to assess the impact of implantation of balloon-expandable stents on right ventricular outflow obstruction in children with congenital heart disease. BACKGROUND: Intravascular stenting has been established as a useful treatment in adults with coronary and peripheral vascular disease. Its application in the treatment of infants and children with pulmonary, systemic and right ventricular conduit obstruction resistant to balloon angioplasty is limited. METHODS: A total of 24 stainless steel stents were implanted in 17 patients. Five stents were placed within right ventricular to pulmonary artery conduits, 17 in branch pulmonary arteries and 1 in an aortopulmonary collateral vessel. Follow-up time has ranged from 1 to 14 months, with 6 patients having hemodynamic and angiographic studies greater than 1 year after stent placement. The mean age at implantation was 7.4 +/- 5.6 years and the mean weight 33 +/- 16 kg. RESULTS: Optimal stent position was obtained in 22 of 24 implantations. In one patient the stent slipped from the delivery balloon and was left positioned in the inferior vena cava. No embolization or thrombotic event has been documented. Among patients with right ventricular to pulmonary artery conduit obstruction, the gradient was immediately reduced from 85 +/- 30 mm Hg to 35 +/- 20 mm Hg after stent implantation; however, three patients required conduit replacement because of persistent obstruction with elevated right ventricular pressures (82 +/- 16 mm Hg). In 10 of 11 patients with pulmonary artery stenosis, clinical improvement was noted in association with enlargement of vessel diameter by 92% +/- 90% (range 17% to 355%) and the gradient reduction of 22 +/- 24 mm Hg to 3 +/- 4 mm Hg. CONCLUSIONS: These data support the view that intravascular stenting will become an important adjunct in the management of children with congenital heart disease.
Child↗
Ventricular performance before and after Fontan repair for univentricular atrioventricular connection: angiographic and radionuclide assessment.
OBJECTIVES: This study was designed to evaluate changes in ventricular volume, mass and cardiac function before and after creation of an atrial to pulmonary connection in patients with a univentricular atrioventricular connection. BACKGROUND: Intact systolic and diastolic performance is critical for successful establishment of an atrial dependent circulation, and few studies are available comparing cardiac performance before and after creation. METHODS: With the use of radionuclide blood pool imaging and ventricular cineangiography, 54 patients (mean age 6.4 +/- 3.4 years) were studied. Twenty-eight patients were investigated preoperatively and 36 greater than 1 year after repair and compared with a control population. RESULTS: Before operation, end-diastolic volume and wall mass were significantly increased compared with those of control subjects; however, the mass/volume ratio was normal (1.08 +/- 0.31 g/ml for the preoperative group; 0.97 +/- 0.19 for control subjects). Although end-diastolic volume returned to normal after the procedure, wall mass remained elevated and contributed to an elevated mass/volume ratio (1.20 +/- 0.38 g/ml). After the procedure, systemic vascular resistance index was significantly elevated compared with that before surgery or with that of control subjects (1,199 +/- 373, 2,120 +/- 645, 1,556 +/- 275 dynes.s.cm-5.m2: pre- and postrepair and control subjects, respectively). Radionuclide studies demonstrated that preoperative ejection fraction (52 +/- 9, 50 +/- 9, 60 +/- 8%), peak ejection (2.58 +/- 0.66, 2.95 +/- 0.81, 3.73 +/- 0.70 EDV/s) and peak filling rates (2.84 +/- 0.75, 2.75 +/- 0.79, 3.84 +/- 0.51 end-diastolic volumes [EDV/s]) were significantly reduced compared with those of control subjects and remained so after surgery. CONCLUSIONS: These data suggest that systolic and diastolic function is depressed preoperatively in these patients, remains unchanged after the creation of an atrial-dependent circulation and is associated with an increased systemic vascular resistance. Long-term issues addressing preservation of cardiac function need to be prospectively studied.
Child↗
Outcome of coronary artery aneurysms after Kawasaki disease.
From 1974 through 1991, a total of 583 children with Kawasaki disease were seen at the Hospital for Sick Children, in Toronto, of whom 80 (13.7%) had coronary artery involvement. There were 55 boys and 25 girls, whose mean age at onset was 2.9 +/- 2.5 years, followed for a mean period of 4.0 +/- 3.6 years. Giant aneurysms (maximum diameter > or = 8 mm) were found in 22 children, moderate-sized aneurysms (> or = 4 to < 8 mm) in 44, and dilation lesions (< 4 mm) in 14. Myocardial infarction occurred in 9 (1.5%), all of whom had giant aneurysms. The persistence rate for aneurysms was 72% at 1 year and 41% at 5 years of follow-up. In multivariate analysis, the regression of an aneurysm was significantly related to the severity of coronary artery lesions, initial treatment, and gender. Although > 80% of small or moderate-sized aneurysms regressed within 5 years, giant aneurysms did not regress during the follow-up period. In patients who received immune globulin therapy, coronary lesions tended to resolve more rapidly than in those treated with salicylate therapy alone, because 91% of the lesions in the former were small or moderate. These findings suggest that the severity of coronary artery involvement during the initial stages of Kawasaki disease influences the regression of these lesions, and that immune globulin treatment may improve outcome by reducing the incidence of severe lesions.
Adolescent↗
The relation between ventricular hypertrophy and clinical outcome in patients with double inlet left ventricle after atrial to pulmonary anastomosis.
To clarify differences between pre- and postoperative volumetric and hemodynamic variables from patients with clinically good and poor outcomes after a Fontan procedure, 40 patients with univentricular heart (double inlet left ventricle) (mean age: 5.7 +/- 3.3 years) were studied using the ventricular cineangiography. According to postoperative clinical findings, patients were classified into two groups: 26 patients with good outcomes and 14 patients with poor outcomes (including five with early and two with intermediate deaths) and compared with a control population. Age at surgery, pre-operative cardiac index, wall mass and systolic ejection phase parameters were not different between the two patient groups, however, end-diastolic volume index in poor outcomes was significantly smaller than those with good outcomes (100 +/- 24, 78 +/- 22, 64 +/- 14 ml/m2: good, poor outcomes and controls, respectively, p less than 0.05), and the mass/volume ratio in this group significantly elevated (1.00 +/- 0.18, 1.19 +/- 0.33, 0.97 +/- 0.19 g/ml, p less than 0.05). Postoperatively, both ventricular volume and mass in good outcomes returned toward the normal and the mass/volume ratio remained within normal range (1.07 +/- 0.22). In contrast, the hypertrophied ventricular mass in those patients with poor outcomes did not decrease in parallel with ventricular volume, thus contributing to a further increased ratio (1.48 +/- 0.19). Although there were no significant differences between pre-operative hemodynamic variables among the two groups, the mass/volume ratio in those with poor outcomes was increased pre-operatively and further increased after the Fontan procedure due to rapid and acute reduction of preload.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
Intraoperative placement of endovascular stents.
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Female↗
Evaluation of ventricular diastolic function in normal children using equilibrium radionuclide angiography.
Twenty children, aged 10.3 +/- 4.5 (3.3 to 17.5) years, were studied by equilibrium radionuclide angiography to establish a normal range for diastolic parameters. Ejection fraction (EF), peak ejection rate (PER) and time to peak ejection rate (TPER), peak filling rate (PFR) and time to peak filling rate (TPFR) were obtained from ventricular time-activity curves and their first derivative curves, and PFR and TPFR were considered as the diastolic parameters. Normal ranges obtained were as follows: EF, 60 +/- 8%; PER, 3.73 +/- 0.70 EDV-1; TPER, 109 +/- 25 ms; PFR, 3.84 +/- 0.51 EDVs-1; TPFR, 136 +/- 21 ms. There were significant correlations between PER and EF (P less than 0.001), PFR and EF (P less than 0.05), while age and heart rate had no influence upon these variables. Such normal ranges will be useful for evaluation of systolic and diastolic function in children with heart disease.
Adolescent↗
Percutaneous implantation of a balloon-expandable endoprosthesis for pulmonary artery stenosis: an experimental study.
Conventional therapy to treat peripheral pulmonary artery stenosis (surgery or balloon angioplasty) has been frustrating. Recently a variety of peripheral vascular stenoses, in which conventional approaches are disappointing, have become amenable to therapy with the use of a balloon-expandable endovascular stent. This experimental study was designed to assess the application of such a prosthesis in artificially created pulmonary artery stenoses. In 9 of 12 2-week old pigs, left pulmonary artery stenosis was surgically created (3.9 +/- 1.1 mm diameter and 7 +/- 1 mm Hg mean gradient). At 6.8 +/- 1 weeks of age (13 +/- 4 kg), percutaneous (femoral venous) implantation of a 3-cm long balloon-expandable (maximal diameter 18 mm) stent (three placed into normal pulmonary artery branches) using a 3-cm x 10-mm balloon dilating catheter was achieved without technical difficulties. Stenoses were enlarged to 8.3 +/- 1.4 mm with a decrease in mean gradient to 1 +/- 1 mm Hg that was maintained through 3.5 months of follow-up. Histologic and electron micrographic studies identified normal-appearing neoendothelial layering over stent struts without intraluminal or peripheral thrombus formation and nonobstructed side branching to lung subsegments. These findings support the application of this approach in the treatment of pulmonary stenosis that is not amenable to conventional therapy.
Animals↗
Ventricular function during supine bicycle exercise in univentricular connection with absent right atrioventricular connection.
Fourteen patients with univentricular connection, absent right connection (tricuspid valve atresia) and normally related great arteries underwent rest and supine bicycle exercise equilibrium radionuclide blood pool studies. Ejection fraction, heart rate, systemic blood pressure and oxygen saturation (ear oximetry) were measured. There were 6 male and 8 female patients. Mean age +/- standard error of the mean was 14.5 +/- 1.1 years (range 6.3 to 21.1). Eight patients (group 1) had systemic to pulmonary shunts placed as palliation 8.2 +/- 2.2 years before study and 6 patients (group II) had caval to pulmonary shunts placed 11.8 +/- 1.6 years previously. Ejection fraction at rest was 54 +/- 2% and an abnormal response to exercise (failure of ejection fraction to increase greater than or equal to 5% from rest to peak exercise) was found in 9 of 14 patients. When analyzed separately, ejection fraction at rest in group I was higher than in group II; however, this difference disappeared at peak exercise. There was a significant negative correlation between ejection fraction at peak exercise and the interval since palliative surgery, although it was not apparent at rest. These data suggest that ventricular function is compromised during exercise and that abnormal performance is influenced by long-standing volume overload. Importantly, this abnormal state is concealed at rest and the choice of palliative shunting procedure appears to have little effect on normalizing pump performance.
Adolescent↗
A femoral vein-femoral artery loop technique for aortic dilatation in children.
Balloon aortic dilatation is now a recognized therapy for aortic stenosis in children. Using retrograde approaches with either single or double balloons, successful dilatation can be readily achieved, but with little control of balloon position across the valve. We describe a femoral vein-femoral artery loop technique via a transseptal approach which facilitates antegrade crossing of the stenotic aortic valve and allows optimal balloon control and simultaneous pressure gradient recording during the procedure.
Adolescent↗
The subclavian artery as the first branch of the aortic arch.
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Aorta, Thoracic↗
Natural history of dilated cardiomyopathy in children.
To assess the natural history and potential risk factors in childhood dilated cardiomyopathy, we investigated 25 patients (ages 9.6 +/- 4.4 years) who presented after they were 2 years old. All patients had symptoms of congestive heart failure and reduced contractility with a dilated left ventricle at presentation. Two factors at presentation were significantly different between patients who died less than 1 year after the presentation (n = 14) and those who survived for more than 1 year (n = 9); cardiothoracic ratio (65.1% +/- 6.8% vs 57.1% +/- 6.1%, p less than 0.01) and left ventricular ejection fraction (31.3% +/- 7.0% vs 40.0% +/- 6.2%, p less than 0.05). Irrespective of intensive medical therapy, dilated cardiomyopathy in children had a poor prognosis; the actuarial survival rate was 41% at 1 year and 20% at 3 years. Other forms of therapy should be considered in the early stages of dilated cardiomyopathy in this high-risk group.
Cardiomyopathy, Dilated↗
Tissue plasminogen activator for the treatment of thromboembolism in infants and children.
We report our experience with the use of tissue plasminogen activator to treat 12 infants and children with various thromboembolic states after conventional thrombolytic agents had failed. The dosage range was between 0.1 to 0.5 mg/kg per hour. Complete clot dissolution occurred in seven cases after 2 hours to 3 days of therapy. Partial clot dissolution and clinical improvement were noted in another four patients. Bleeding complications were noted in 6 of the 12 patients and included bruising, oozing from various venipuncture sites, and bleeding; these complications were controlled by clinically available means. In all cases with bleeding the dose rate was in the higher range (0.46 to 0.50 mg/kg per hour). In one patient, restlessness, agitation, and screaming were noted during administration of tissue plasminogen activator and when it was reinstituted. We conclude that tissue plasminogen activator is effective in inducing clot lysis in children. Because the effective dose appears to overlap with those causing bleeding, we recommend that a dose of 0.1 mg/kg per hour be started and increased gradually if clot dissolution does not occur, with close monitoring for bleeding.
Adolescent↗
Immunosuppressive therapy in the management of acute myocarditis in children: a clinical trial.
To assess whether steroid therapy influenced the clinical course of myocarditis in a pediatric population, findings in 13 consecutive infants and children (8 female, 5 male) with biopsy-proved myocarditis were reviewed. The mean age was 5.7 +/- 4.8 years (range 1.1 to 14.8). Congestive heart failure was present in all as were ST-T wave changes, cardiomegaly and pulmonary edema on chest roentgenogram. Echocardiography demonstrated pericardial effusion in five patients and mitral regurgitation in eight. Mean left ventricular ejection fraction was 34 +/- 12%. Prednisone was administered to all patients; one patient also received azathioprine. There was one death. All survivors showed clinical improvement with normalization of ECG changes, heart size and systolic function. No significant side effects occurred. Repeat myocardial biopsy in eight patients demonstrated improvement in all eight and elimination of the inflammatory infiltrate in six. Immunosuppressive therapy in this pediatric population appeared useful in improving the clinical course and cardiac function in acute myocarditis with no adverse side effects.
Azathioprine↗
Repair of coarctation of the aorta in children: postoperative morphology.
To determine the morphologic sequelae after surgical repair of coarctation of the aorta, the authors retrospectively reviewed angiograms and hemodynamic and clinical data on 215 patients who underwent cardiac catheterization after surgical repair of coarctation of the aorta during a 13-year period. Ninety-seven patients (45%) underwent coarctation resection with end-to-end anastomosis; 92 (43%), subclavian-flap angioplasties; and 26 (12%), synthetic-patch repairs. Sixty-four patients (30%) had an "aneurysm," defined as a measurement ratio of repair site to diaphragmatic aorta greater than 1.5. Transverse-arch or isthmic hypoplasia or recoarctation was detected in 86 patients (40%) and was most commonly associated with septal defects or obstruction of the left ventricular outflow tract. Pullback systolic pressure gradients at catheterization were significantly higher (P = .0001) in the patients with transverse-arch hypoplasia and recoarctation than in those with ratios of transverse arch to diaphragmatic aorta greater than 0.9. Significant postoperative arch obstructions can be predicted with measurement ratios on the basis of the diameter of the abdominal aorta.
Adolescent↗
Transcatheter occlusion of the persistently patent ductus arteriosus. Forty-month follow-up and prevalence of residual shunting.
BACKGROUND: Percutaneous closure of the persistently patent ductus arteriosus with the Rashkind prosthesis is an established effective therapeutic modality, although some patients are left with residual shunting. To evaluate this, a retrospective study of the prevalence of persistent shunting over a 40-month period in the first 190 patients was undertaken. METHODS AND RESULTS: All patients (male 45, female 145; mean age, 3.9 +/- 3.6 years; range, 5 months to 20 years) had serial clinical and color-flow echocardiographic follow-up at 6-12-month intervals (range, 6-40 months). Four patients required surgical removal of an embolized device, leaving a cohort of 186 patients in whom 196 procedures were performed, resulting in successful placement of 195 devices (43 17-mm [22%] and 152 12-mm [78%]). Complications occurred in seven of 195 procedures (3.6%). Nine of 10 attempted reocclusions (all with 12-mm devices) were successful. The prevalence of residual shunting was 38% at 1 year, 18% at 2 years, and 8% at 40 months. Patients with ductus measuring less than 4 mm had a higher success of initial occlusion. Thirty-four patients were left with residual shunting determined by color-flow Doppler study, but no anatomic or echocardiographic features were found predictive for residual shunting. All remain asymptomatic with 26 (76%) having no detectable murmur, two (6%) a continuous murmur, and six (18%) a systolic murmur. CONCLUSIONS: Catheter occlusion will obviate the need for surgery in the majority of patients presenting with persistently patent ductus arteriosus. Reocclusion has been found feasible in those with continuous murmurs (nine of nine) and should be offered early because it is unlikely for spontaneous closure to occur in this group. It appears prudent to follow those with small residual shunting because further spontaneous closure can occur.
Adolescent↗
Age-related response to epinephrine-induced myocardial stress. A functional and ultrastructural study.
Left ventricular systolic and diastolic function before, during, and after a 2-hour intravenous infusion of epinephrine at either 0.5 micrograms/kg/min or 2 micrograms/kg/min were assessed by pressure-volume data obtained by conductance catheter micromanometer technique and correlated with cardiac ultrastructure and plasma levels of epinephrine in neonatal (3-5 days old, n = 12) versus adult (3-4 months old, n = 11) pigs. Administration of epinephrine at 0.5 micrograms/kg/min resulted in an increase in end-systolic elastance (Ees) only in adults, whereas at 2.0 micrograms/kg/min Ees increased in both groups. After 2-hour administration of epinephrine at 2.0 micrograms/kg/min, Ees decreased significantly (p less than 0.05) from the preinfusion baseline value of 8.9 +/- 2 (mean +/- SD) to 5 +/- 1.7 mm Hg/ml, and a significant (p less than 0.05) increase in left ventricular volume elasticity (VdP/dV) from 0.4 +/- 0.02 to 1.4 +/- 0.2 mm Hg occurred in neonates versus no change from baseline in either Ees or VdP/dV in the adults. These changes in the neonates were associated with sarcolemmal rupture and mitochondrial Ca2+ granule deposition versus normal cardiac ultrastructure in the adults. We conclude that the neonatal myocardium is more susceptible to cardiotoxicity from circulating epinephrine.
Aging↗