Biomedical subjects
Publications and source records attributed to S E Fletcher.
We report on successful transcatheter therapy of congenital pulmonary arteriovenous malformation resolving persistent cyanosis and obviating the need for surgical pneumonectomy or lobectomy.
OBJECTIVE: Our goal was to determine whether CT angiography can reveal complications in pediatric patients and young adults treated with intravascular stents for obstructive vascular lesions. CONCLUSION: CT angiography can reveal complications in pediatric patients treated with intravascular stents for obstructive lesions. Potentially, CT angiography could replace the more invasive conventional angiography currently used for intravascular stent placement and follow-up examinations.
Development of a mycotic aneurysm or pseudoaneurysm after subacute bacterial endarteritis is uncommon. Nonetheless, patients with coarctation of the aorta are more likely to develop this complication. We describe a case of a large pseudoaneurysm discovered in a child with a previously undiagnosed aorta coarctation. Successful repair was performed with the aid of partial left heart bypass and the use of an interposition graft. A high index of suspicion is necessary to accurately diagnose this rare but life-threatening entity.
Children with congenital heart disease present major problems with venous access, eliminating conventional routes for cardiac catheterization. Although the transhepatic approach has recently gained popularity, we describe here an alternative approach using percutaneous translumbar approach for cardiac catheterization and/or in-dwelling central line insertion in three children with congenital heart disease. Diagnostic hemodynamic studies, transcatheter delivery of an intravascular stent for left pulmonary artery (LPA) stenosis, and chronic central venous line insertion were performed using this technique. Disadvantages include interventionalist's unfamiliarity with technique, awkward patient positioning, technically more difficult than transhepatic, and potential injury to kidney and bowel. Advantages include avoidance of vascular-rich hepatic parenchyma, thus reducing risk of hemorrhage; providing an alternative where transhepatic entry may be contraindicated; avoidance of bile duct, portal vein, and hepatic artery injury; and providing another alternative for not only transvenous, but also transarterial access that may be required for intravascular aortic stent delivery. The interventional radiologist should be utilized as a valuable resource to the cardiologist to help teach and supervise this technique in selected infants and children with limited vascular access.
OBJECTIVE: To determine the accuracy of expert examination for pulmonary stenosis (PS) among children with murmur. STUDY DESIGN: Five hundred twenty-one consecutive, previously unevaluated, pediatric patients were enrolled. The investigators prospectively recorded their diagnosis and level of confidence, categorizing any PS suspected as mild or severe. After echocardiography, PS was categorized by severity with peak systolic flow velocity. Receiver operating characteristic curves described accuracy of clinical examination. RESULTS: Sixty-two patients had PS (mild, 29; moderate, 27; and severe, 6). Receiver operator characteristic curve areas were: total, 0.834 +/- 0.033; mild, 0.862 +/- 0.044; and moderate to severe, 0.809 +/- 0.046 (P =.20). Specific difficulties in discrimination of PS from small ventricular septal defect, aortic valve disease, atrial septal defect, and innocent murmur were identified. All cases of severe PS in which PS was suspected were thought possibly severe. CONCLUSIONS: Although expert clinical examination is highly accurate for distinguishing PS from non-PS cardiac murmurs in pediatric patients, it is imperfect.
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The new 2 French Coe radiofrequency (RF) end hole catheter was first used to successfully perforate the atretic pulmonary valve membrane using an antegrade approach in a newborn with intact ventricular septum (IVS). Nine watts of energy for 8 sec was required with simultaneous delivery of a 0.014 in. coronary guidewire coaxially through the end hole RF catheter for balloon valvuloplasty. This new ringed-tip end hole RF catheter offers considerable advantages to the pediatric interventionalist in the transcatheter therapy in neonates with pulmonary atresia (PA) and IVS.
OBJECTIVES: This study was undertaken to determine the accuracy of expert examination for ventricular septal defect (VSD) among children with a heart murmur. BACKGROUND: Because the frequency and nature of errors that might be made by reliance solely on expert examination for diagnosis of VSD are speculative, the role of echocardiography in such diagnosis is controversial. METHODS: Two hundred eighty-seven consecutive previously unevaluated pediatric subjects were enrolled in the study. For each child, the pediatric cardiologists prospectively recorded a working diagnosis and their level of confidence in the diagnosis, categorizing any VSD diagnosed as small or moderate to large. After echocardiography, VSDs were subcategorized by location and requirement for treatment as minor, intermediate or major. Receiver-operating characteristic (ROC) curves described the accuracy of the clinical examination. RESULTS: Seventy-three subjects had a VSD (minor in 52, intermediate in 10 and major in 11). ROC areas (1.0 = perfect discrimination, 0.5 = indiscriminate) were minor VSD 0.92 +/- 0.02 and major/intermediate VSD 0.69 +/- 0.07 (p = 0.0016). Four of 52 minor VSDs were not identified at any level of suspicion; the clinical diagnoses were moderate to large VSD in two patients and atrial septal defect and unlimited differential diagnosis in one patient each. Fourteen of 235 patients without a minor VSD were believed with confidence to have a small VSD, but the final diagnosis was intermediate VSD in 4, innocent murmur in 3, major VSD in 2, pulmonary stenosis in 2 and subaortic membrane, atrial septal defect and mitral regurgitation in 1 patient each. CONCLUSIONS: Almost all minor VSDs are recognized without echocardiography; however, errors can occur even when an expert examiner is confident. Clinical recognition of an intermediate or major VSD is less accurate than clinical recognition of a minor VSD. Failure to distinguish VSDs of major or intermediate importance from minor VSDs is a weakness of the expert clinical examination.
Improved catheter and device technology has allowed the practice of pediatric interventional catheterization to expand in recent years. One such example of technologic advancement has been the development of an intravascular snare by Microvena (White Bear Lake, MN). We present three patients in which the snare was effectively used to perform definitive transcatheter therapy and avoid the need of more invasive surgical treatment. We believe that the snare device significantly decreased our fluoroscopic and procedural time and facilitated the effectiveness of the specific procedure.
Moderate to severe aortic stenosis in children requires an initial procedure to improve the stenosis and often additional procedures for recurrent stenosis or aortic insufficiency before adulthood. The purpose of this study was to evaluate children who underwent balloon valvuloplasty and were followed with a specific management plan. Twenty-two children with aortic stenosis underwent balloon valvuloplasty and were followed on a regular basis. Repeat valvuloplasty was performed if indicated. The initial gradient was reduced from 63 +/- 9 mmHg to 28 +/- 8 mmHg (P < 0.001). There were no deaths and only one major complication, which had no sequelae. Average follow-up was 61 +/- 23 months. Three patients required valve replacement 39-76 months after valvuloplasty for progressive insufficiency. Seven patients underwent successful repeat valvuloplasty. The overall probability of survival without surgical intervention was 75% at 100 months. Balloon valvuloplasty is an effective intermediate palliation for aortic stenosis and is an acceptable alternative to surgical valvotomy. Repeat valvuloplasty is successful without additional risk. In a subgroup of patients, aortic insufficiency is progressive and will require surgical intervention.
UNLABELLED: OBJECTIVES, This retrospective analysis was designed to examine the intermediate and long-term effects of balloon angioplasty for native coarctation of the aorta and to determine whether any factors are predictive of outcome. BACKGROUND: Balloon angioplasty for native coarctation of the aorta is controversial. Concerns exist over lack of long-term follow-up and possible formation of aneurysms. The role of transverse arch and isthmus hypoplasia after balloon dilation is unknown. METHODS: Included in the study were all patients 3 days to 29 years old (mean age 4.6 years) referred for possible balloon dilation to the pediatric cardiac catheterization laboratory with evidence of a discrete coarctation of the aorta. The hemodynamic data, angiograms and clinical records of 102 patients were examined, with follow-up data from 2 to 117 months (median 36.2) available in 92 patients. RESULTS: Immediate success with balloon angioplasty was achieved in 93 (91.2%) of the 102 patients. Seventy-one patients (77.2%) with intermediate follow-up data (range 12 to 117 months) available are asymptomatic and normotensive, with insignificant arm to leg blood pressure gradients (< or = 20 mm Hg). Twenty-one patients (22.8%) with an initial successful result developed an increase in gradient 2 at 86 months after angioplasty, requiring reintervention in 18. Follow-up > 72 months is available in 17 patients, 16 of whom are normotensive and have not required additional intervention. No additional intervention was needed in 88.4% of older children and infants > 7 months old. Ten of the 13 surviving neonates who initially had a successful dilation required reangioplasty or operation 14 days to 10 months (median 4.6 months) after angioplasty. Transverse arch hypoplasia had minimal effect on follow-up blood pressure gradient, whereas isthmic hypoplasia was associated with reintervention in 50%. A small aneurysm was noted in 2 (1.9%) of 102 patients. CONCLUSIONS: Balloon angioplasty of native aortic coarctation is effective in infants and older children. In neonates, balloon angioplasty provides effective palliation only. Aneurysm formation is rare; however, lifetime follow-up is warranted.
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Because imipramine and desipramine have been implicated in sudden death in children, noninvasive electrophysiologic data were accumulated in 25 patients. Two children were excluded on the basis of resting electrocardiographic and Holter abnormalities. The remaining 23 patients received imipramine to a maximum dose of 5 mg/kg or a serum level of 150 to 250 ng/ml. Consistent but clinically insignificant resting electrocardiographic changes occurred during treatment. Ambulatory electrocardiographic monitoring may be useful when one is assessing the cardiovascular risks of imipramine therapy.
Radiofrequency catheter ablation is fast becoming the procedure of choice for the nonpharmacological treatment of atrioventricular connections that are responsible for debilitating tachycardias. We, herein, present a case of reentrant supraventricular tachycardia secondary to an atrioventricular connection in a Fontan patient that was successfully treated with radiofrequency catheter ablation.
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We report a case of myocardial necrosis in a newborn after treatment of the mother with long-term subcutaneous terbutaline. No such serious side effects in the fetus have previously been reported. We speculate that this myocardial damage was due to beta-sympathomimetic therapy.
The cytotoxic effects of cis-diamminedichloroplatinum(II) (cis-DDP) were shown to be strongly potentiated by hyperthermia. The molecular mechanisms responsible for this potentiation were investigated by assaying the degree of DNA cross-linking produced under the different drug treatment conditions by the technique of alkaline elution. The results showed that the cells treated with the drug at 43 degrees had a greater amount of DNA cross-linking immediately after treatment than did cells treated with the drug at 37 degrees, indicating a possible thermal enhancement of drug uptake by the cells. Whereas the hyperthermia potentiated the cytotoxicity of cis-DDP by a factor of nearly 10, the degree of DNA cross-linking was only enhanced by a factor of 6.5, suggesting that while a large portion of the enhanced cytotoxicity may be attributed to the increased cross-linking other factors may also play some role. The possible influence of hyperthermia on the repair of the DNA damage induced by cis-DDP was investigated; however, no significant differnence in the rate of disappearance of cross-links between cells treated at 37 or 43 degrees was observed. Advantageous combination of chemotherapy with cis-DDP and hyperthemia for the treatment of cancer is implied by these results.