Kenneth E. Fellows

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.

Late ventricular geometry and performance changes of functional single ventricle throughout staged fontan reconstruction assessed by magnetic resonance imaging

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.

A Study in Ventricular–Ventricular Interaction Single Right Ventricles Compared With Systemic Right Ventricles in a Dual-Chamber Circulation

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.

A Study in Ventricular–Ventricular Interaction

Background Ventricular–ventricular interaction is known to occur in the 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 st...

Balloon dilation angioplasty of postoperative aortic obstructions

Balloon dilation angioplasty (BDA) was attempted 29 times in 27 patients, aged 3 months to 22 years, with postoperative aortic obstructions. Previous operations included end-to-end anastomosis (n = 10), subclavian flap angioplasty (n = 7) and patch angioplasty (n = 3) for aortic coarctation, end-to-end anastomosis for interrupted aortic arch type B (n = 4) and aortic arch reconstruction for hypoplastic left heart syndrome (n = 3). Two of the patients with interrupted arch had multiple areas of obstruction. Balloon sizes were between 2 and 6 times the diameter of the lesion and up to twice the diameter of the proximal transverse arch (mean 1.1). BDA was at least partially successful (more than 50% decrease in gradient and more than 30% increase in diameter) in 26 of the 29 procedures (90%). BDA failed in the 2 lesions with an initial diameter of more than 8 mm. No differences were apparent in the success rate among any of the clinical groups. Peak systolic gradient decreased from 42 +/- 14 to 14 +/- 15 mm Hg (p less than 0.01) and mean diameter increased from 4.1 +/- 2.6 to 6.8 +/- 3.2 mm (p less than 0.01). There was no mortality or significant acute morbidity associated with the procedure. After 1 to 24 months of follow-up, restenosis has occurred in only 1 patient. Aneurysm formation was found in 2 of 5 patients who had undergone repeat catheterization; both aneurysms occurred in patients with repaired interruption of the aortic arch.(ABSTRACT TRUNCATED AT 250 WORDS)

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 Childrens 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.

Results of routine preoperative coronary angiography in tetralogy of Fallot.

In the surgical repair of tetralogy of Fallot, morvidity and mortality are increased by certain coronary anomalies, in particular, an anterior descending branch originating from the right coronary artery or a single coronary artery in which a large coronary branch runs across the pulmonary outflow tract. In series of 94 patients with tetralogy of Fallot who underwent cardiac catheterization, coronary artery visualization was attempted routinely, most often by flush aortography using a venous catheter. Diagnostic coronary visualization was obtained in 84 patients (89%). In these, the incidence of recognized coronary anomalies was 5%; anterior decending from the right coronary artery in four patients (4%), and singly left coronary in one patient (1%). In 195 autopsied cases of tetralogy, the incidence of coronary anomalies was also 5%. Routine preoperative demonstration of the coronary artery anatomy in tetralogy patients usually can be accomplished satisfactorily and conveniently by transvenous flush aortography.

Fibrinolytic therapy for femoral arterial thrombosis after cardiac catheterization in infants and children

The charts of 79 patients who required femoral arterial (FA) thrombectomy after cardiac catheterization were reviewed. Fifteen patients (19%) had poor pulses after thrombectomy and 2 had an extremity amputated. One thousand consecutive patients undergoing cardiac catheterization were also studied to prospectively determine the safety and efficacy of systemic fibrinolytic therapy for treatment of FA thrombosis. Among these, 771 patients underwent retrograde arterial catheterization, including 31 patients with left-sided obstructive lesions who had undergone transarterial balloon dilation procedures with large catheters. All patients were given heparin at the time of arterial cannulation. Patients who had a pulseless extremity 4 hours after catheterization continued to receive heparin therapy for 24 to 48 hours. If the extremity continued to have no palpable pulse and the systolic blood pressure was less than 50% of that in the contralateral leg, intravenous streptokinase infusion was begun. The overall incidence of FA thrombosis was 3.6% (28 of 771), including 39% (12 of 31) of all patients undergoing transarterial balloon dilation procedures; 97% (27 of 28) of patients weighed less than 14 kg and the majority weighed less than 10 kg. After an average treatment period of 33 hours, 16 patients continued to have a pulseless extremity and were treated with streptokinase for an average duration of 13 hours. Normal pulses and systolic blood pressure returned in 14 (88%) and were nearly normal in 1 other patient (6%). The incidence of bleeding at the arterial puncture site was 25% and was highest in the patients who had a transarterial balloon dilation procedure. No serious complications occurred.

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.

Balloon dilation of the aortic valve: Studies in normal lambs and in children with aortic stenosis

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)