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Between March 1995 and February 2000, 10 children with major thromboses were treated with local pharmacomechanical thrombolysis. Clinical improvement was found in 8 patients: follow-up angiography showed complete thrombus resolution in 5 patients and subtotal resolution in 4.

Objectives: To identify infants with hyperinsulinism caused by defects of the beta-cell adenosine triphosphate-dependent potassium channel complex and to distinguish focal and diffuse forms of hyperinsulinism caused by these mutations., Study Design: The acute insulin response to intravenous calcium stimulation (CaAIR) was determined in 9 patients <20 years with diffuse hyperinsulinism caused by defective beta-cell sulfonylurea receptor (SUR1(-/-)), 3 patients with focal congenital hyperinsulinism (6 weeks to 18 months), a 10-year-old with insulinoma, 5 with hyperinsulinism/hyperammonemia syndrome caused by defective glutamate dehydrogenase (6 months to 28 years), 4 SUR1(+/-) heterozygotes with no symptoms, and 9 normal adults. Three infants with congenital focal disease, 1 with diffuse hyperinsulinism, and the child with insulinoma underwent selective pancreatic intra-arterial calcium stimulation with hepatic venous sampling., Results: Children with diffuse SUR1(-/-) disease and infants with congenital focal hyperinsulinism responded to CaAIR, whereas the normal control group, patients with hyperinsulinism/hyperammonemia syndrome, and SUR1(+/-) carriers did not. Selective arterial calcium stimulation of the pancreas with hepatic venous sampling revealed selective, significant step-ups in insulin secretion that correlated anatomically with the location of solitary lesions confirmed surgically in 2 of 3 infants with congenital focal disease and in the child with insulinoma. Selective arterial calcium stimulation of the pancreas with hepatic venous sampling demonstrated markedly elevated baseline insulin levels throughout the pancreas of the infant with diffuse hyperinsulinism., Conclusions: The intravenous CaAIR is a safe and simple test for identifying infants with diffuse SUR1(-/-) hyperinsulinism or with focal congenital hyperinsulinism. Preoperative selective arterial calcium stimulation of the pancreas with hepatic venous sampling can localize focal lesions causing hyperinsulinism in children. The combination of these calcium stimulation tests may help distinguish focal lesions suitable for cure by local surgical resection.

Pediatric thoracic vascular abnormalities include many anatomic variants and pathologic conditions. Although some vascular variants are inconsequential and are discovered incidentally on imaging studies, several anomalies have profound effects on the airway and pulmonary parenchyma. Imaging plays a key role in evaluating the chest and its vasculature. The chest radiograph is usually the first screening study performed during the course of evaluation for a vascular abnormality. Cross-sectional imaging with CT and magnetic resonance imaging provides precise anatomic information and has in most cases replaced invasive diagnostic angiographic procedures. We describe common thoracic vascular abnormalities that occur in children and the imaging techniques currently used in their evaluation.

Abnormal ventricular systolic torsion is present during histological rejection in adult cardiac transplant patients. Because biomechanical properties of transplanted hearts in the baseline state have not been studied in children, pediatric patients were evaluated to quantify ventricular wall motion and strain. Eight transplant studies and eight normal controls were evaluated. Magnetic resonance tagging was performed to determine radial shortening, twist, and strain in four ventricular anatomic areas at two short-axis levels. Controls had counterclockwise twist. Six transplant studies had clockwise twist, six had akinetic regions, and all had regions of no twist. One demonstrated paradoxical motion of the septum. A comparison between transplant patients and controls revealed strain to be similar in all regions except one (superior wall at the atrioventricular valve level) and strain distribution to be different only in two of eight regions. Pediatric transplant patients demonstrate regional wall motion abnormalities in the absence of rejection. Compared with normal controls, the transplanted left ventricle maintains normal strain in the presence of abnormal twist. This may be a compensatory mechanism and have clinical implications.

The alterations in anatomy and physiology, which often accompany congenital heart disease, may have a major impact on the child's lungs. These changes in pulmonary blood flow and ventilation are usually demonstrable on chest radiography and should be recognized as manifestations of the underlying lesion and not mistaken for primary lung disease. Correlation with the clinical history and physical examination are essential for correct interpretation, but radiological findings should be viewed objectively and without bias to provide accurate and valuable information to the treating physician.

Objective: In order to achieve more "timely" interpretation of radiologic examinations, a 3 to 11 p.m. attending radiologist slot was incorporated into the daily schedule utilizing existing staff. Our purpose was to assess the effectiveness of this practice by measuring report generation times., Material and Methods: Using a radiology information system (DecRAD), the time between completion of the technical examination and dictation of the official report for general (plain film) studies was determined for a 2-month period and compared to similar periods 1 and 2 years prior to instituting extended hours. Emergency and portable (ICU) exams were similarly analyzed., Results: The number of examinations reported within 2 h of technical completion increased by 8.5% (mean); reporting within 4 h increased by 20%; reporting within 6 and 12 h of completion each increased by 24%. Over 80% of cases were dictated within 12 h after the change in practice occurred; whereas, it took up to 24 h in preceding years. Analysis of emergency and portable ICU exams showed similar trends, and the number of next day "call-backs" to the emergency department was significantly reduced., Conclusion: By extending attending coverage, more plain film examinations, especially emergency cases and ICU portables, were read and reported within a shorter time providing prompt communication with clinicians and more opportunity to influence management decisions.

Objectives: Our objectives were twofold: (1) to determine cardiac and respiratory dependency of systemic venous pathway flow of patients having the Fontan operation with a total cavopulmonary connection and (2) to describe the velocity profile. Systemic venous pathway flow is hypothesized to be mostly respiratory dependent, to be laminar, and to have a smooth velocity profile., Methods: Twenty-two patients having the Fontan operation (aged 8.6 +/- 4.7 years) underwent magnetic resonance blood tagging (bolus tagging). Systemic venous pathway spin-echo images parallel to the blood flow were used as a localizer. A saturation pulse labeled the blood, and a cine image was acquired at the inferior and superior venae cavae and midportion of the baffle in the systemic venous pathway, triggered to the electrocardiogram and gated to both end-expiration and end-inspiration. Repetition time was 50 msec., Results: Flow in the systemic venous pathway was laminar throughout its course and was found to be phasic to both cardiac and respiratory cycles. Approximately 70% of flow was cardiac dependent, and the rest was respiratory. Highest flow occurred near end-systole and early diastole and in inspiration. Lowest flow occurred in diastasis. Velocity was highest and flow least "pluglike" in the mid-baffle area during cardiac or respiratory imaging (45 +/- 17 and 32 +/- 11 cm/sec, respectively)., Conclusion: A substantial amount of pulmonary blood flow in patients who have undergone a total cavopulmonary connection type of Fontan operation has a cardiac component. Furthermore, we confirm that this flow is laminar but nonuniform across the systemic venous pathway. Highest flows occurred near end-systole and early diastole, as well as in inspiration, and the lowest flow occurred in diastasis. This information may help in designing the systemic venous pathway and optimizing medical management.

Background: The aorta that has undergone an aorta-pulmonary artery anastomosis may not exhibit the same velocity profile as the nonreconstructed aorta, whose velocity profile is thought to be uniform across the vessel diameter (plug flow). This may have an impact on fluid dynamics and will alter Doppler flow calculations. Our objective was to determine the impact of surgical reconstruction on the velocity and flow profiles of the reconstructed ascending and descending aorta., Methods: Using a magnetic resonance imaging tagging technique that labels flowing blood (bolus tagging), we studied 22 patients (mean age, 8.6 +/- 4.7 years) who had had a Fontan procedure. A cine sequence labeled the blood and acquired the image after 20 ms in the middle of the ascending aorta and behind the left atrium in the descending aorta. The repetition time was 50 ms., Results: The reconstructed ascending aorta displayed a velocity profile skewed anteriorly, whereas in the nonreconstructed aorta, the velocity profile was flat. Reconstructed aortas also displayed flows that were higher anteriorly, took a longer time to reach maximum velocity, and were less like "plug" flow than the nonreconstructed aorta. The descending aorta, regardless of whether aortic reconstruction was present, displayed velocity profiles (at various phases of systole) skewed posteriorly., Conclusions: The reconstructed aorta displays disturbed flow, and the velocities across the ascending aortic diameter are more varied than those in aortas without reconstruction and are skewed anteriorly. The descending aortic velocity profile in children is skewed posteriorly, regardless of whether aortic reconstruction is present. This information may help design and build a "better" aortic reconstruction.

Objectives: We sought to test the hypothesis that late ventricular geometry and performance changes occur in functional single ventricles as they progress through staged Fontan reconstruction., Background: Indexes of ventricular geometry and performance are important in evaluating the functional state of the heart. Magnetic resonance imaging determines these indexes in complex ventricular shapes with minimal geometric assumptions. Previous studies have shown that 1 week after hemiFontan, the mass/volume ratio markedly increases., Methods: Multiphase, multislice, spin echo (n = 5) and cine (n = 30) magnetic resonance imaging was performed in 35 patients with a functional single ventricle (1 week to 12 years old) at various stages of Fontan reconstruction (15 in the pre hemiFontan stage, 11 after [6 to 9 months] the hemiFontan procedure and 9 after [1 to 2 years] the Fontan procedure). Volume and mass were calculated at end-systole and end-diastole. Ventricular output was then obtained. Ventricular centroid motion was also calculated., Results: No difference was noted (power > 72%) from the pre hemiFontan stage to 6 to 9 months after the hemiFontan procedure in (mean +/- SD) end-diastolic volume (104 +/- 24 vs. 123 +/- 40 cc/m2), mass (171 +/- 46 vs. 202 +/- 61 g/m2), ventricular output (7.9 +/- 2.2 vs. 6.6 +/- 2.4 liters/min per m2) or centroid motion (6.9 +/- 2.8 vs. 6.7 +/- 2. mm/m2). Patients in the Fontan group demonstrated a marked decrease in all indexes, indicating significant volume unloading and decrease in mass and ventricular performance. Mass/volume ratio was not significantly different among all three groups., Conclusions: No geometric and performance changes from the volume-loaded stage are noted 6 to 9 months after the hemiFontan procedure; however, major changes occur 1 to 2 years after the Fontan procedure. The dramatic changes in the mass/volume ratio seen early after the hemiFontan procedure were not detected at 6 to 9 months. Furthermore diminution of mass, volume and ventricular performance are present at least 2 years after the Fontan procedure.

Background: Ventricular-ventricular interaction is known to occur in normal human heart. To determine whether it plays a role in the function of single right ventricles, systemic right ventricles were compared with and without a left ventricle mechanically coupled to it., Methods and Results: A noninvasive magnetic resonance tagging technique (spatial modulation of magnetization [SPAMM]) that lays intersecting stripes down on the myocardium was used to examine 18 patients with systemic right ventricles: 7 with a single right ventricle who have undergone the Fontan procedure (age, 38.8 +/- 8.9 months) and 11 with transposition of the great arteries who have undergone an atrial inversion operation (age, 16.3 +/- 3.9 years). The motion of the intersection points was tracked through systole to determine regional twist and radial shortening. Shortening rates also were evaluated. Finite strain analysis was applied to the grid lines using Delaunay triangulation, and the two-dimensional strain tensor and principal E1 strains were derived for the various anatomic regions. Basal and apical short-axis planes through the ventricular wall were categorized into four distinct regions spaced equally around the circumference of the slice. We observed the following results. (1) Strain was greatest and heterogeneity of strain was least in patients with transposition of the great arteries who were status post atrial inversion operation (six of eight regions). Marked differences were noted in the distribution of strain within a given region, from endocardium to epicardium, and from atrioventricular valve to apical plane between patient subtypes and those with a normal left ventricle. (2) Contrary to the normal subject studied by the use of the same method, for both patient subtypes, there was counterclockwise twist in one region, clockwise twist in the posterior or inferior wall, and a transition zone of no twist at which the two regions of twist met. Normal human adult left ventricles studied in short-axis twist uniformly counterclockwise as viewed from apex to base. (3) Radial inward motion was greatest in the superior wall of both types of systemic right ventricle. The inferior walls of Fontan patients and the posterior (ie, septal) walls of patients with transposition of the great arteries, status post atrial inversion, moved paradoxically in systole. The shortening rate at the atrioventricular valve of patients with transposition of the great arteries, status post atrial inversion, was significantly lower than at the apex or in Fontan patients., Conclusions: Marked differences in regional wall motion and strain were demonstrated in systemic right ventricles, depending on whether a left ventricle was present to augment its function. Ventricular-ventricular interaction appears to play an important role in affecting the biomechanics of systemic right ventricles. These observations were markedly different from those in the normal systemic left ventricle. These techniques demonstrate tools with which we can begin to evaluate surgical outcomes using regional myocardial mechanics and may provide a clue to single right ventricle failure.

We describe a technique of direct puncture and catheterization of the hepatic veins for cardiac catheterization and radiologic intervention in children who lack conventional access routes. Four patients underwent eight direct hepatic vein punctures to allow cardiac catheterization (3 patients) and 5-12 F sheath insertions for balloon dilatation of hepatic vein stenoses (1 liver transplant patient). Gelfoam was injected in the sheath tract for hemostasis. All procedures were successful, including five hepatic vein dilatations and right heart access for three cardiac catheterizations. There were no complications. When conventional venous access is precluded, direct percutaneous catheterization of hepatic veins is easy, effective, and probably low risk.

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.

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.

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)

The purpose of this article is to provide an update of pediatric interventional procedures for the interventionalist, and especially for those who treat children infrequently. Most pediatric interventional procedures are modifications of techniques devised for adults, in that some are unique to pediatrics. These are stressed in the presentation.

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.

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.

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.

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.

Thirty specially designed 4 French pigtail white Teflon catheters 50 cm in length were utilized for angiography using the retrograde arterial approach in 26 infants and children. Angiographic opacification was considered very satisfactory. Apart from one episode of temporary occlusion of the right coronary artery ostium, there were no other significant complications. The catheters were introduced percutaneously in 21 instances and distal pulses were palpable in 18 patients by the second day after catheterization. At postcatheterization testing with increasing volumes and flow rates, the first rupture occurred, delivering 13 ml at 13 ml/second. On testing an additional 15 catheters using fixed volumes of 5, 10, and 15 ml at increasing flow rates, rupture first occurred at 34, 22, and 18 ml/second, respectively. We conclude that this small catheter is relatively safe and satisfactory for the retrograde arterial approach in the study of infants and children.

Nine cases are reported of perimembranous ventricular septal defect associated with left ventricular to right atrial shunting. Cineangiographic findings included an aneurysm of the membranous septum in all patients; two patients had obvious adherence of deformed tricuspid valve leaflets to the membranous septum. The location of the ventricular septal defect was confirmed at surgery or cardiac endoscopy in seven patients. In the presence of a perimembranous ventricular septal defect, left ventricular to right atrial shunting is usually the result of tricuspid valve abnormalities, including clefts or perforations of the septal leaflet, deformity or adherence of valve tissue to the margins of the septal defect and widening of the anteroseptal commissure. Biplane left ventriculography, using the long axial oblique and reciprocal right anterior oblique projections, may best demonstrate the pathologic anatomy, although the hepatoclavicular projection is a useful alternative, particularly when an atrioventricular canal defect is a diagnostic consideration.

The radio- and angiocardiographic characteristics of 19 infants with an interrupted aortic arch were reviewed. There were three with type A (distal to the left subclavian artery), 15 with type B (between the left carotid and subclavian arteries), and one with type C (between the innominate and left carotid arteries). Associated cardiovascular anomalies were numerous, a ventricular septal defect (19/19) and a patent ductus arterisous (18/19) being the most common. Plain film signs of aortic interruption were nonspecific. Left ventriculography using angled oblique views was diagnostic of the interruption and most other abnormalities. The constant presence of a ventricular septal defect and frequent occurrence of left ventricular outflow obstruction in these infants lends support to the theory that decreased flow in the fetal ascending aorta predisposes to interruption of the aortic arch.

Nine cases of combined double-chambered right ventricle (DCRV) and discrete subaortic stenosis (DSAS) are presented. A review of 1077 consecutively catheterized patients indicates an association of these two uncommon anomalies nine times greater than expected. One or both obstructive lesions may be hemodynamically significant and require surgery. Whenever DCRV or DSAS is suspected or identified, the cardiac catheterization should include studies of both the right and left ventricles.

Retrograde arterial catheterization was performed in 105 infants and small children (median age 6 mo) using a 3.2 French pigtail catheter made of ultrathin walled white Teflon. Three catheter lengths were used, (40, 50, and 65 cm). Pressure recordings and ease of sampling were judged excellent in all. All 118 angiograms (60 ventricular) were performed without complication except for two episodes of external catheter rupture. Angiographic quality was rated excellent in 41%, good in 39%, fair in 18%, and poor in only 2%. Among the 81 patients in whom only this catheter was used percutaneously, pedal pulses were lost in 5%. Postcatheterization testing identified ranges of volume and flow-rate characteristics which included 8 ml at 15 ml/sec (40 cm length), at 11 ml/sec (50 cm length), and at 9 ml/sec (65 cm catheter). We conclude that this small catheter is relatively safe and satisfactory for retrograde catheterization of infants and small children.

To evaluate the risks of and optimal method for valve dilation in aortic stenosis, balloons of different sizes were used to dilate the normal aortic root in 16 lambs and then stenotic valves in 15 children. In the lambs, inflated balloon to aortic anulus diameter ratios ranged from 0.9 to 1.5. These hearts were examined immediately after the procedure. Ratios of 0.9 to 1.1 did not produce significant damage to the left ventricular outflow tract, whereas those of 1.2 to 1.5 produced tears or hematomas, or both, of the aortic valve leaflets (n = 3), mitral valve leaflets (n = 4) and interventricular septum (n = 4). The 15 patients, aged 10 days to 15 years, underwent 16 balloon aortic valvotomy procedures. The balloon-aortic anulus ratio ranged from 0.67 to 1.1 (mean 0.90). The average pressure gradient decreased 69% and, overall, the peak systolic gradient decreased from 86 +/- 21 to 28 +/- 14 mm Hg (p less than 0.01) and the aortic valve area increased from 0.44 +/- 0.11 to 0.73 +/- 0.22 cm2/m2 (p less than 0.01). Immediately after the procedure an increase in aortic regurgitation was noted in 8 (57%) of 14 patients, but was never greater than 3+ and has been well tolerated. Other early complications encountered consisted of transient left bundle branch block in two patients, temporary femoral artery occlusion in three and femoral artery rupture requiring operative management in one infant. Balloon valvotomy can reduce the transvalvular gradient in most patients with valvular aortic stenosis when a balloon less than 1.1 times the aortic root diameter is used.(ABSTRACT TRUNCATED AT 250 WORDS)