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Biomedical subjects

K E Fellows

Publications and source records attributed to K E Fellows.

At least 37 records · Page 2Linked to original sources
PubMed1994

Vascular imaging in children.

Advances in technology have brought about the wide variety of imaging modalities that are presently available. The development of digital subtraction angiography, computed tomography, ultrasonography, and magnetic resonance imaging have had a particular impact on vascular imaging. These modalities, general principles of study selection, and imaging approaches for specific entities are reviewed.

Adolescent↗
PubMed1994

Contemporary interventional procedures for vascular disorders in children.

Pediatric interventional radiology offers new treatment options not possible a few years ago. Interventional radiologists treat not only certain causes of hemorrhage but also symptomatic arteriovenous malformations, renovascular hypertension, and portal hypertension. Interventionalists help maintain liver and renal transplants, increasing transplant patient survival. In addition to these selected disorders and types of radiological intervention, specific procedures such as thrombolysis, transjugular intrahepatic portosystemic shunts, and maintenance of hemodialysis access are discussed.

Adolescent↗
PubMed1993

Magnetic resonance imaging of constant total heart volume and center of mass in patients with functional single ventricle before and after staged Fontan procedure.

It has been previously demonstrated that total heart volume (contents of pericardium) throughout the cardiac cycle varies by < 5% and location of center of mass by < 3 mm. The hypothesis has thus developed that for maximal efficiency, the heart should expend minimal energy in displacing extracardiac structures by maintaining a constant intracycle total heart volume and center of mass. This is achieved in the normal heart mainly by a piston-like movement of the atrioventricular valve plane toward the ventricular apex. As this has never been studied in the single ventricle heart or at various stages of Fontan reconstruction, it is conceivable that these patients may not exhibit the constancy of total heart volume and location of center of mass, which may lead to a poor outcome in some. The total heart volume and center of mass relationship was therefore evaluated in 25 children (0.4 to 237 months) with functional single ventricles at all stages of Fontan reconstruction using multiphase, multislice spin-echo or cine-magnetic resonance imaging. No significant difference was seen in variation between total heart volume and maximal volume between patients before bilateral cavopulmonary anastomosis (hemiFontan) (5.1 +/- 2.9%), after hemiFontan (3.6 +/- 1.6%) and after Fontan (8.2 +/- 7.7%); however, in 4 of 10, 1 of 8 and 5 of 7 patients, respectively, the total heart volume varied by < 5%. Across surgical subgroups, significant differences were found in the center of mass displacement (total, anteroposterior and superoinferior planes) but not in directionality of displacement.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1992

Evaluation of congenital heart disease with MR imaging: current and coming attractions.

Nearly 10 years of experience in the use of MR imaging for the diagnosis of congenital heart disease has accumulated. Although MR imaging is superior to other techniques in showing certain structures and abnormalities such as small central pulmonary arteries in tetralogy of Fallot, aortic coarctations, and venous connections in heterotaxia syndromes, it remains an ancillary tool to echocardiography and cardiac catheterization. In this review, we examine present limitations and advantages of conventional MR in the evaluation of congenital anomalies of the heart and great vessels and explore future developments that might bring MR imaging into the diagnostic mainstream. Key improvements now in development are ultrafast MR systems for acquisition of multiple real-time MR images (in 30 msec or less) and on-line three-dimensional computer reconstruction of the heart and great vessels. Improved display and understanding of complex anatomy, as well as more extensive functional analysis of hearts before and after surgery, should be the benefits of such developments.

Adolescent↗
PubMed1991

Multiple collaterals to hepatic infantile hemangioendotheliomas and arteriovenous malformations: effect on embolization.

Hemangioendotheliomas and arteriovenous malformations (AVMs) of the liver often cause congestive heart failure in babies, but embolization of the hepatic artery is not always effective. Six newborns and infants (four with hemangioendotheliomas and two with AVMs) underwent abdominal aortography, hepatomesenteric arteriography, and angiography of arterial and portal collateral vessels prior to embolization of the hepatic artery for heart failure (n = 5) and portal hypertension (n = 1). In addition, extrahepatic arteries were embolized in one patient and a portal vein branch in another. Extrahepatic arterial collaterals from the superior mesenteric, intercostal, phrenic, and adrenal arteries were seen in five patients; portal vein connections, in two patients. Embolization was therapeutically most effective in the baby with the least collateral supply and in the two patients in whom arterial collaterals or portal venous connections were embolized. Angiographic documentation and possibly embolization of collateral flow is required to improve treatment planning and success in these severely ill patients.

Angiography↗
PubMed1990

Long follow-up (to 43 years) of ventricular septal defect with audible aortic regurgitation.

From 1946 to March 1989, 92 patients (33 women and 59 men) were seen with ventricular septal defect (VSD) and audible aortic regurgitation (AR). The VSD was subcristal in 62 patients, subpulmonary in 21 and unknown in the remaining 9. The median age of onset of AR was 5.3 years. The risk of developing AR was 2.5 times greater in those with a subpulmonary VSD. The aortic valve was tricuspid in 90% and bicuspid in 10%. Prolapse was seen in 90% of those with subcristal VSD and in all with subpulmonary VSD. Pulmonary stenosis was seen in 46% of the patients with gradients ranging from 10 to 55 mm Hg. The incidence of infective endocarditis was 15 episodes/1,000 patient years. Among 20 patients followed medically, for 297 patient years, 1 died (1959) and most have been stable, including 2 followed for greater than 30 years. In the 72 patients operated on, there were 15 perioperative and 5 late deaths. Operations consisted of VSD closure alone in 7, VSD closure and valvuloplasty in 50 and VSD closure and aortic valve replacement in the other 15. Valvuloplasty was more effective in those operated on under age 10 compared to those older than 15 years (46 vs 14%). The durability of the valvuloplasty was 76% at 12 years and 51% at 18 years.

Actuarial Analysis↗
PubMed1990

Bronchial artery embolization for severe hemoptysis in cystic fibrosis.

We studied the long-term outcome after BAE for life-threatening hemoptysis in patients with CF. Data from pulmonary function tests were available for 18 of the 25 patients followed. A case-control comparison revealed that these 18 patients died sooner than hemoptysis-free patients with CF matched for age, sex, and pulmonary function (p less than 0.02), with the excess mortality occurring within the first three months after BAE. Of all 25 patients followed, six died of cardiorespiratory failure within three months of BAE; in two of them, hemoptysis was a contributing cause of death. The 19 patients who lived more than three months after BAE had a mean survival after embolization of 3.5 years (five were still alive at the end of the study). Most patients experienced long intervals (greater than 1 year) free of major hemoptysis. Extended follow-up (mean, 35 months) revealed a higher incidence of recurrent severe bleeding than previously reported for 13 of these patients followed a mean of 11 months. Repeat BAE for severe recurrence was performed successfully in eight of nine patients, without complication.

Adult↗
PubMed1989

The association of congenital neuroblastoma and congenital heart disease. Is there a common embryologic basis?

Several authors have reported an association between neuroblastoma and congenital heart disease; others contend that, unlike specific well-known associations between malignancy and congenital defects (Wilm's tumor and aniridia, leukemia and Down's syndrome), no real relationship exists. We present three cases of cyanotic congenital heart disease in which subclinical neuroblastoma was found. We speculate that abnormal neural crest cell migration and development may be a common link between cardiac malformations and congenital neuroblastoma.

Cell Movement↗
PubMed1989

Coil embolization to occlude aortopulmonary collateral vessels and shunts in patients with congenital heart disease.

Gianturco coils were used to embolize 77 vessels in 54 patients: 58 aortopulmonary collateral vessels, 14 Blalock-Taussig shunts, 3 arteries involved in pulmonary sequestrations and 2 venae cavae. Embolization resulted in total occlusion in 53 (69%), subtotal occlusion in 19 (25%) and partial occlusion in 3 (1 intentional). Two embolizations failed to reduce flow. Thus, 72 (95%) of 76 embolizations in which complete occlusion was the intended result resulted in total or subtotal occlusion. Analysis of the results demonstrates that completely occluded collateral vessels were longer and had a smaller diameter than did incompletely occluded vessels. Complications included six cases of inadvertent embolization to the pulmonary arteries (n = 5) or the aorta (n = 1); three were retrieved and three were left without symptoms. In addition, there was a case of severe hemolysis after intentional partial occlusion of a Blalock-Taussig shunt. The results demonstrate that coil embolization can be an effective procedure for managing a wide variety of aorto-pulmonary collateral vessels and shunts in children with congenital heart disease.

Adolescent↗
PubMed1988

Comparison of digital with conventional ventriculography for quantitative right ventricular studies.

To assess the feasibility of quantitative central venous digital angiocardiography, right ventricular spatial orientation, size, and shape were compared with measurements based on conventional angiocardiography, both obtained during routine cardiac catheterization in 21 children with various congenital heart defects. Without systematic error, correlations for end-diastolic and end-systolic volumes were excellent, at r = 0.986 and 0.969, respectively. Ejection fractions were similarly closely correlated. Premature ventricular contractions were common in conventional angiocardiography and absent in digital and angiocardiography. The amount of contrast medium was 36% of that used for conventional angiocardiography. Digital angiocardiography using reduced amounts of contrast medium given through a central venous catheter allows accurate assessment of right ventricular size and function.

Adolescent↗
PubMed1988

Balloon dilation of critical pulmonary stenosis in the first week of life.

Although balloon dilation of valvular pulmonary stenosis is established in infants and children, the techniques for and results of balloon dilation in neonates with critical pulmonary stenosis remain largely unreported. Since January 1, 1985, six successive neonates with critical pulmonary stenosis (aged 1 to 6 days) underwent attempted balloon dilation. Each was cyanotic and three of the six were on prostaglandin E1 therapy and three required tracheal intubation and ventilation. All had suprasystemic right ventricular pressures (mean 122.8 +/- 6.8 mm Hg). After hemodynamic evaluation and right ventricular angiography, the valve was crossed in five patients, and was first dilated with a low profile, 5 or 6 mm diameter, 2 cm long balloon. At least one more balloon was used in each patient, the largest being 95 to 133% of the diameter of the pulmonary valve anulus. The anulus size was 6.8 +/- 1.1 mm and the largest balloon size used was 6 to 10 mm. Right ventricular pressure decreased to nearly systemic level or less in five of five patients (58.8 +/- 6.7 mm Hg). Pressure gradients, measured in four infants, were 7, 12, 16 and 35 mm Hg, respectively, but were unreliable indicators of obstruction because of a patent ductus arteriosus. The five patients were discharged 3 to 8 days after balloon dilation. All are currently symptom free 10.6 +/- 11.7 months later, and all but one are believed clinically to have mild obstruction. Complications included iliac vein occlusion (n = 1) and complete right bundle branch block (n = 1). Although follow-up has been brief, neonates with critical pulmonary stenosis can safely undergo balloon dilation, usually with good short-term results.

Catheterization↗
PubMed1987

Acute complications of catheter therapy for congenital heart disease.

Although therapeutic catheter procedures for congenital heart disease are still developing, the number of procedures being performed allows statistically relevant review of the acute complications. Between January 1, 1984, and February 1, 1987, 417 such procedures were performed at The Children's Hospital, Boston; the age range of the patients was 1 day to 51 years (median 4 years, 6 months). Catheter procedures consisted predominantly of vascular dilations (peripheral pulmonic stenosis, 97; valvular pulmonic stenosis, 67; valvular aortic stenosis, 62; recurrent coarctation, 49) and embolizations (double umbrella device, 36; steel coils, 45). Overall, there were 50 acute complications (12%); 24 (6%) were major and 26 (6%) were minor. The mortality rate was 3 of 417 (0.7%). Complication rates varied between 4% for dilation of recurrent coarctation and 40% for dilation of aortic stenosis. The age of the patients was a factor in complications of vascular access (11 patients), 8 of which occurred in patients younger than 6 months (median 5), and in cardiac arrest and ventricular fibrillation (4 patients, 3 of whom were younger than 6 months [median 3]). No statistically significant trend toward diminishing overall complication rates was discerned over the 37 months of this study.

Acute Disease↗
PubMed1987

Nonutility of cineurograms in children with congenital heart disease.

Cineurography is often performed after cineangiocardiography to look for occult congenital urinary tract disease. The accuracy of cineurography was investigated in 171 patients by comparing cineurograms with renal sonograms. One hundred fifteen cineurograms (67%) showed both kidneys well enough to allow assessment of renal structure and function and the results were confirmed in 112 by ultrasonography; 3 cineurograms yielded false-positive results. Limited or no information was obtained from cineurograms of 56 patients (33%) because of nonvisualization or poor visualization of 1 or both kidneys. Of the 11 patients (6%) with urinary tract disease, only 3 were correctly assessed by cineurography. Ultrasonography discovered all 11 renal abnormalities and produced only 1 false-positive result. These data indicate that cineurography is a poor screening test and should be abandoned. When uroradiologic screening is necessary for high-risk patients, sonography is recommended.

Adolescent↗