Biomedical subjects
Publications and source records attributed to Robert M Freedom.
At 24 weeks gestational age, a term female infant was diagnosed with complex congenital heart disease. The antenatal cardiac diagnosis was uncertain and included univentricular heart. Following delivery, the child remained well and was normally saturated. Echocardiography and angiocardiography revealed an unusual relationship between atria and ventricles.
OBJECTIVES: We described morphologic characteristics, particularly pulmonary anatomy, and determined the prevalence of definitive end states and their determinants in children with pulmonary atresia associated with ventricular septal defect (PAVSD). BACKGROUND: Pulmonary atresia associated with ventricular septal defect represents a broad morphologic spectrum that greatly influences management and outcomes. METHODS: From 1975 to 2004, 220 children with PAVSD presented to our institution. Blinded angiographic review (n = 171) characterized bronchopulmonary segment arterial supply. RESULTS: A total of 185 patients underwent surgery, and repair was definitive in 75%. Initial operations included systemic-pulmonary artery shunt in 57%, complete primary repair in 31%, or right ventricular outflow tract reconstruction in 12%. Based on angiographic review, 118 patients had simple PAVSD and 53 patients had PAVSD with major aortopulmonary collateral arteries (MAPCAs). Overall survival from initial operation was 71% at 10 years. Risk factors for death after initial operation included younger age at repair, earlier birth cohort, fewer bronchopulmonary segments supplied by native pulmonary arteries, and initial placement of a systemic-pulmonary artery shunt. Competing-risks analysis for initially palliated patients predicted that after 10 years, 68% achieved complete repair (with associated factors including later birth cohort and more bronchopulmonary segments supplied by native pulmonary arteries), 22% died without repair, and 10% remained alive without repair. Reoperations after complete repair occurred in 38 children (27%), with risk factors including older age at palliation, MAPCAs, and more segments supplied by collaterals. CONCLUSIONS: Outcomes in children with PAVSD have improved over time, and are better in completely repaired cases. Bronchopulmonary arterial supply is an important determinant of mortality, achievement of definitive repair, and post-repair reoperation.
BACKGROUND: There are no large series describing the morphologic spectrum and the clinical outcomes of children with ductal origin of the distal pulmonary artery (PA). METHODS: Medical records were reviewed for all children presenting between 1970 and 2001. Angiograms were reviewed at presentation and at last available follow-up. RESULTS: Forty-five patients were identified with median presenting age of 14 days (range, birth to 6.5 years). Ductal origin of the distal PA occurred as an isolated finding in 16 patients (36%), with tetralogy of Fallot in 12 (27%), with pulmonary atresia-ventricular septal defect in 13 (29%), and with heterotaxy in 4 (9%). Diagnostic pulmonary venous wedge angiography was performed in 21 patients (47%). Surgical procedures were undertaken in 31 patients, and were initial systemic-ductal PA shunt in 13 patients, interposition graft in 6, direct anastomosis to the main PA in 2, ductal PA banding in 2, unifocalization of the ductal PA with complete or staged pulmonary atresia-ventricular septal defect repair in 7, and heart transplantation in 1 patient. Surgical revision was required in 3 patients and catheter interventions in 12 patients. Overall 20-year survival was 70% and was improved among patients without congestive heart failure at presentation (p = 0.08, hazard ratio: 2.81). Reconstruction of the ductal PA decreased the prevalence of pulmonary parenchymal hypoplasia (p < 0.001) and scoliosis at last available follow-up. CONCLUSIONS: Ductal origin of the distal PA is associated with important multisystem morbidity and mortality. Early diagnosis and repair of the ductal PA, especially in children presenting with pulmonary overcirculation, may improve outcomes.
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Right aortic arch with isolation of the left subclavian artery is a rare disorder. In this entity, the left subclavian artery has its origin from the pulmonary artery via the ductus arteriosus. We report an infant with an unbalanced atrioventricular septal defect, right aortic arch, bilateral ductus arteriosi and an isolated left subclavian artery. This infant also had chromosome 22q11 deletion. The origin and course of the isolated subclavian artery were well-demonstrated using contrast-enhanced 3-D magnetic resonance angiography. This non-invasive diagnostic modality can accurately reveal detailed mediastinal vascular anatomy in a young infant and allows diagnosis of aberrant vascular connections.
BACKGROUND: Non-compaction of the left ventricular myocardium is an important cause of cardiomyopathy. There is no clear consensus about its diagnostic criteria or the diagnostic test of choice. MRI is increasingly used in the pediatric cardiac field because of its superior and objective image quality. OBJECTIVE: To compare the echocardiographic and MRI findings in four patients with recently diagnosed ventricular non-compaction. MATERIALS AND METHODS: We compared the extent of myocardial involvement shown at MRI and echocardiography in four individuals, two patients with echocardiographic diagnosis of left ventricular non-compaction, and two family members of one of the patients. RESULTS: In all patients, MRI showed wider area of involvement than echocardiography. A definite diagnosis was entertained in only two patients by echocardiography but in all by MRI. Cine imaging was diagnostic of the disease in all patients. Black-blood pool imaging with double-inversion recovery sequence also helped to visualize the abnormal areas by showing slow flow artifacts in the four- and two-chamber images. CONCLUSION: MRI provided better delineation of the extent of the abnormal trabeculation in patients with non-compaction of the left ventricular myocardium. It was particularly useful when the myocardial involvement was subtle, as in the asymptomatic family members.
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BACKGROUND: Parachute mitral valve (PMV) is defined as a unifocal attachment of the mitral valve chordae to a single or dominant papillary muscle and may cause subvalvar obstruction. We sought to determine factors associated with outcomes. METHODS AND RESULTS: Patients (n=84; 64% male) who presented between 1977 and 2001 at a median age of 3 days (range, birth to 5.4 years) were assessed with PMV (without atrioventricular septal defect). Associated cardiac anomalies in 99% included aortic coarctation in 68%, atrial septal defect in 54%, ventricular septal defect in 46%, aortic valve stenosis in 32%, subaortic stenosis in 20%, and left ventricular hypoplasia in 19%, with complex anomalies in 14%. Noncardiac anomalies were noted in 32%. Survival (n=18 deaths) was 82% at 1 year and 79% at 10 years, with independent risk factors including left ventricular hypoplasia (P<0.001) and atrial septal defect (P<0.003). Freedom from surgical mitral valvotomy (n=11 patients) was 95% at age 6 months and 80% at 10 years, with independent risk factors including the absence of aortic coarctation (P<0.02) and the presence of subaortic stenosis (P<0.04). There was no significant increase in mean gradient of the PMV over time, but higher gradient was independently associated with the presence of supravalvar mitral stenosis (P<0.001), absence of atrial septal defect (P<0.04), presence of ventricular septal defect (P<0.02), and subsequent mitral valvotomy (P<0.01). CONCLUSIONS: Outcomes for patients with PMV are dependent on the spectrum of associated cardiac lesions. The degree of mitral valve obstruction remains stable, and the majority will not require valvotomy.
The atrial switch operation was developed by the efforts of many surgeons, with the most notable contributions made by Blalock, Hanlon, Albert, Baffes, Senning, and Mustard. The atrial switch operation was the first definitive repair for patients with transposition of great arteries and produced good results. Although it is rarely performed today, the atrial switch is not merely of historical interest as there remain a few important indications for this operation. A thorough understanding of the atrial switch is still required for surgeons dealing with complex congenital cardiac malformations. Herein we summarize the history, review long-term results, and discuss the future of the atrial switch operation.
BACKGROUND: Interrupted aortic arch (IAA) continues to be associated with important mortality, both before and immediately after repair, with ongoing morbidity during follow-up. We sought to determine trends in presentation, management, outcomes and associated factors. METHODS: We reviewed all consecutive patients (n = 119) presenting from 1975 to 1999, and data were collected regarding demographics, anatomy, management and outcomes. RESULTS: Significant trends over time for patients born in three consecutive periods (1975 to 1984, 1985 to 1993, and 1994 to 1999) demonstrated a smaller proportion of patients with presentation with circulatory collapse (65%, 51%, and 25%, respectively), greater use of prostaglandins (72%, 90%, 100%), fewer deaths without IAA repair (49%, 15%, 13%) and greater use of one-stage repair (68%, 75%, 100%). Independent risk factors for death without IAA repair (p < 0.001) included absence of ventricular septal defect, and the presence of noncardiac anomaly, complex cardiac anomaly, episode of acidosis and earlier birth cohort. Overall survival after repair was 50% at age 1 month, 35% at 1 year, and 34% at 5 years. Early and constant-hazard phases were noted, with incremental risk factors for early phase mortality being cyanosis at presentation, presence of truncus arteriosus or aortic stenosis, an episode of circulatory collapse before repair, earlier date of repair, and lower weight at repair. Greatest survival occurred in those patients with uncomplicated IAA who had repair since 1993 (5 year survival, 83%). Freedom from reintervention for arch obstruction was 60% at 5 years. CONCLUSIONS: While improving, outcomes of IAA remain of concern, especially in patients with associated lesions.