Search PubMed⌕ Search

Biomedical subjects

A R Castaneda

Publications and source records attributed to A R Castaneda.

At least 55 records · Page 3Linked to original sources
PubMed1990

Mitral valve replacement in the first year of life.

From 1973 through 1987 25 patients underwent mitral valve replacement in the first year of life for mitral stenosis and mitral regurgitation. The patients with mitral stenosis included two with mitral arcade, two with supravalvular mitral stenosis with hypoplastic mitral valve, and one with parachute mitral valve. Included in the group of patients with mitral regurgitation were 12 with atrioventricular canal defect, six with chordal and leaflet defects, one with Marfan's syndrome, and one with bacterial endocarditis. Prostheses included 12 Björk-Shiley (17 mm), seven St. Jude Medical (19 mm in four, 21 mm in three), five stent-mounted dura mater valves (12 mm to 16 mm), and one porcine xenograft (19 mm). In four patients the valves were placed in the left atrium in a supraannular location. There were nine operative (atrioventricular canal defect seven, mitral regurgitation two) and five late (atrioventricular canal defect four, mitral stenosis one) deaths, giving actuarial 1- and 5-year survival rates of 52% and 43%, respectively. All 6 patients with tissue valves died; the four with supraannular mitral valve replacement survived. Since 1983 operative mortality has been reduced to 0% (70% confidence limits 0% to 24%). Nine patients required a second mitral valve replacement for prosthetic stenosis 5 to 69 (mean 30) months after the original mitral valve replacement (one operative death). Because of improvements in repair of atrioventricular canal defect in infancy, the need for mitral valve replacement at atrioventricular canal defect repair has decreased. Although valvuloplasty has been advocated for repair of congenital mitral valve disease and is applicable in some infants with mitral regurgitation, mitral valve replacement is frequently unavoidable for congenital mitral disease and can now be accomplished at a low operative risk, even when the prosthesis has to be positioned supraannularly.

Age Factors↗
PubMed1990

Orthotopic heart transplantation for complex congenital heart disease.

Orthotopic heart transplantation has become standard therapy for end-stage cardiomyopathy in children and adults, but there has been much less experience with transplantation for complex congenital heart disease. In this report experience with orthotopic transplantation in seven children with various forms of complex congenital heart disease is reviewed. Diagnoses included hypoplastic left heart syndrome in two (after stage I palliation), left ventricular diverticulum in one, single ventricle in two (dextrocardia, atrial situs inversus, and total anomalous pulmonary venous return in one patient and post-Fontan repair in the second), D-transposition of the great arteries and ventricular septal defect (post-Senning repair and ventricular septal defect closure) in one, and Ebstein's anomaly with biventricular dysplasia in one. Six of the seven were hospital survivors and there has been one late death at 2 1/3 years. Modifications of the standard operative technique to fit the anatomic variations in these defects are reviewed.

Adolescent↗
PubMed1989

Truncus arteriosus.

Explore the source record for details and available documents.

Abnormalities, Multiple↗
PubMed1989

Neonatal critical valvar aortic stenosis. A comparison of surgical and balloon dilation therapy.

Balloon aortic valvotomy (BAV) is an alternative to surgical valvotomy in infants and children. We compared BAV in 16 consecutive neonates (1985-1988) to surgical valvotomy in a prior group of 16 consecutive neonates (1978-1984). Both groups were comparable in terms of age, weight, hemodynamic data, left ventricular size, and associated lesions. There were six early and one late deaths after surgery. Five out of six neonates requiring a second operation died. Left ventricular size (measured in 13 neonates) had some influence on survival after surgery: three of three with small or hypoplastic left ventricles and three of 10 with normal-sized left ventricles died. After BAV, there were three early deaths, two patients who underwent stage I palliation of hypoplastic left heart syndrome, and two late deaths. As with surgical valvotomy, left ventricular size seemed to influence survival after BAV: five of six with small or hypoplastic left ventricles died or underwent stage I palliation for hypoplastic left heart syndrome and two of nine with normal-sized left ventricles died. At follow-up (26 +/- 17 months) in six patients in the surgical group, the peak systolic ejection gradient (PSEG) was 52.2 +/- 23 mm Hg and left ventricular end-diastolic pressure (LVEDP) 18.2 +/- 5.2 mm Hg. Aortic regurgitation was mild in five and moderate in the sixth patient. At follow-up (17.6 +/- 7.8 months) in nine patients in the balloon dilation group, the PSEG was 45.6 +/- 11 mm Hg in five patients at catheterization and 43.8 +/- 22.9 mm Hg in four patients by echocardiography-Doppler. Aortic regurgitation was mild in three and absent in the other six patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve↗
PubMed1989

Transposition of the great arteries: the arterial switch operation.

Primary arterial switch operation in neonates for repair of transposition of the great arteries with an intact ventricular septum or with a ventricular septal defect has become the operation of choice in our institution. By now, the surgical risk has been decreased to approximately 2 per cent. Early in our experience, postoperative supravalvar pulmonary stenosis was the only late hemodynamic complication of significance. Postoperative left ventricular function, including echocardiographic indices of left ventricular function, including echocardiographic indices of left ventricular systolic and diastolic function, have been within normal range in all patients. Almost all patients are in sinus rhythm as late as 6 years of the operation. It is our contention that primary arterial switch operation in infants with transposition of the great arteries results in improved left ventricular performance; the potential hazard of late coronary insufficiency and of aortic valve dysfunction requires continued monitoring of these patients.

Aorta, Thoracic↗
PubMed1989

Comparison of technetium-99m MIBI and thallium-201 chloride myocardial scintigraphy in infants.

Myocardial perfusion scintigraphy was performed with both 201Tl and a new six coordinate monocationic isonitrile complex of 99mTc, [99mTc]2-methoxyisobutylisonitrile (MIBI), on 11 infants who had undergone the arterial switch procedure for transposition of the great arteries. Unlike 201Tl which can show rapid and variable rates of washout from myocardium, 73% of the initial first-pass activity of the isonitrile complex in the myocardium remains 1 hr after intravenous administration. The images obtained with [99mTc]MIBI required a shorter recording time, entailed less radiation exposure to the patient, and were qualitatively at least as good as those obtained with 201Tl. No infant had perfusion abnormalities. The potential applications of the isonitrile complexes for myocardial perfusion scintigraphy in children are discussed.

Female↗
PubMed1989

Rapid, two-stage arterial switch for transposition of the great arteries and intact ventricular septum beyond the neonatal period.

Optimal management of dextrotransposition of the great arteries with intact ventricular septum is currently an arterial switch procedure performed in the first 2 weeks of life. However, a subgroup of patients presents for surgery beyond this time for reasons of sickness, size, or late referral. Experience with 11 such patients (mean age at first-stage procedure, 4.5 months) has revealed that the left ventricle can be prepared by a surprisingly short interval period (median, 9 days) between a first-stage preparatory operation (pulmonary artery band with or without a shunt) and a subsequent second-stage arterial switch procedure. Serial two-dimensional echocardiography showed that left ventricular mass increased by a mean of 85% during this short interval. Mean left ventricular-right ventricular-pressure ratio as measured by cardiac catheterization increased from 0.5 +/- 0.08 a median of 7 days before the first stage to 1.04 +/- 0.29 a median of 7 days after the first stage. One patient underwent a Senning procedure because of an intramural left coronary artery. The other 10 patients underwent an arterial switch, with no early deaths. Median hospitalization after the arterial switch was 8 days. There has been one late death at 5 months. No patient has been detected to have abnormal ventricular function, although trivial to mild aortic regurgitation has been commonly observed with color flow mapping. These results have encouraged us to offer a two-stage arterial switch procedure to appropriate infants with an interval period of approximately 1 week. Both stages can be performed at one hospitalization, with important psychosocial, logistic, and financial advantages.

Cardiac Catheterization↗
PubMed1989

The neonate with critical congenital heart disease: repair--a surgical challenge.

Primary neonatal repair of congenital heart defects offers a number of potential advantages over a two-stage approach, but the application of this principle has been limited by the perceived increased risk of neonatal repair. However, the patient with palliative CHD continues to suffer from secondary effects on the central nervous system, the pulmonary arteries, the airways, and the heart itself. Because these consequences have been increasingly recognized, we have undertaken primary repair of a variety of defects within the first months of life. From January 1983 through August 1988, 304 neonates with a critical congenital heart defect underwent primary repair with deep hypothermic circulatory arrest or low flow perfusion techniques. The total mortality rate was 11.8%. The largest number of patients had transposition of the great arteries--167 neonates--with a total hospital mortality of 8.9%. Aspects of preoperative evaluation and management, intraoperative care, including anesthesia and cardiopulmonary bypass, and deep hypothermia (with or without circulatory arrests), as well as postoperative management, are discussed. These data suggest that many forms of complex congenital heart defects may be successfully repaired during the neonatal period. Improved methods of preoperative resuscitation and postoperative care have contributed to these results. Follow-up hemodynamic and electrophysiologic studies have confirmed the advantages of early repair. Elective repair of the neonate with a complex congenital heart defect looms as a goal in the not-too-distant future.

Cardiopulmonary Bypass↗
PubMed1989

Aortic atresia with normal left ventricle. Single-stage repair in the neonate.

Four to seven percent of infants born with aortic atresia have a normal-sized left ventricle in association with a ventricular septal defect and a normal mitral valve. In contrast to the more common group of infants with aortic atresia whose left ventricle is hypoplastic, this important subgroup has potential for complete operative correction involving both the right and left ventricles. Previous reports of surgical management of these infants have described early palliative procedures to control systemic and pulmonary blood flow. Our approach has been to perform complete repair at one stage in the neonate. Continuity between the proximal main pulmonary artery and aorta is established, a patch on the ventricular septal defect baffles left ventricular blood to the pulmonary valve, and a homograft conduit achieves right ventricular-pulmonary artery continuity. Three of four neonates who underwent single-stage repair were discharged from the hospital in good condition. Achieving a physiologically normal circulation simplifies the postoperative management of this condition and is to be preferred over neonatal palliation.

Aortic Valve↗
PubMed1988

A new sealant for knitted Dacron prostheses: minimally cross-linked gelatin.

There has been a resurgence of interest in the concept of presealing high-porosity knitted Dacron prostheses with an absorbable biologic material. Such a material should provide reliable porosity control, preferably reducing water porosity from 2000 ml/cm2/min to less than 50 ml/cm2/min. It should not interfere with the fibrous and vascular ingrowth that securely anchors the developing pseudointima. In previous studies, we have examined fibrin glue and two forms of aldehyde cross-linked insoluble collagen used as Dacron sealants. We concluded that delayed resorption of the sealant as seen with glutaraldehyde cross-linked insoluble collagen results in undesirable healing characteristics, particularly lack of adhesion between pseudointima and the luminal surface of a prosthesis. This study examines a new sealant. Soluble collagen (gelatin) is treated to reduce the number of free amino groups available for aldehyde cross-linking. It is then weakly cross-linked with an aldehyde mixture and applied to a knitted Dacron prosthesis. Water porosity studies have confirmed satisfactory porosity control. Both rat subcutaneous and canine circulatory implants for 6 months reveal relatively rapid and complete sealant resorption without undesirable modification of the normal healing process of knitted Dacron.

Animals↗
PubMed1988

Modified Fontan procedure: atrial baffle and systemic venous to pulmonary artery anastomotic techniques.

Two technical modifications to the modified Fontan procedure are presented. Systemic venous to pulmonary artery continuity is achieved by superior vena cava (SVC) division and end to side anastomosis to the right pulmonary artery (RPA), particularly following a right Blalock shunt, or by RPA division and anastomosis to the SVC, particularly in the presence of RPA stenosis. Intra-atrial partitioning is achieved by a systemic venous baffle rather than a pulmonary venous baffle. This is particularly useful in the presence of left atrioventricular valve atresia, but may be a preferable technique with double-inlet single ventricle or single ventricle with common AV valve. These techniques were applied successfully to 10 of 12 children with various forms of single ventricle, including 5 with left AV valve atresia or stenosis.

Adult↗
PubMed1988

Late results in patients with tetralogy of Fallot repaired during infancy.

Between 1973 and 1985, 220 infants (age 1 day to 18 months, mean = 7 months) underwent repair of tetralogy of Fallot (TOF) or TOF/pulmonary atresia with 17 early deaths. Follow-up status was ascertained for 184 of 203 survivors (91%) at a postoperative interval of 2 to 185 months (mean = 60 months). Significant residual hemodynamic lesions included ventricular septal defect in three, and right ventricular outflow gradient in excess of 40 mm Hg in 24. Reoperation or interventional catheter procedures were performed in 31 of 184 (17%) patients. All postoperative electrocardiograms were reviewed; only two of 184 patients had ventricular ectopy on any tracing. Holter data from 41 patients revealed one with sinus node dysfunction, 12 with Lown grade 1 ectopy, and one with Lown grade 2 or greater. Conduction defects, evaluated by electrocardiographic and electrophysiologic measurements, were not different from those reported for TOF patients undergoing repair at later ages. No study patient received antiarrhythmic medication, although one required a pacemaker for sinus node dysfunction. There were three late deaths, all unrelated to arrhythmia. TOF repair in infancy appears to be associated with an acceptable hemodynamic outcome, and a low incidence of ventricular ectopy and sudden death at 5 year follow-up.

Arrhythmias, Cardiac↗
PubMed1988

Myocardial performance after arterial switch operation for transposition of the great arteries with intact ventricular septum.

Left ventricular dimensions, wall thickness, wall stress, and indexes of afterload, preload, contractility, and early diastolic function, as well as regional wall motion, were determined by echocardiographic methods in patients with transposition of the great vessels after arterial switch operation and in age-matched normal controls. In patients evaluated early after surgery, body surface area-adjusted left ventricular dimensions were smaller, and wall thickness was increased compared with controls. Ventricular performance (fractional shortening) was normal in most patients but was abnormally low in 10%. Nevertheless, contractility was normal or augmented in all subjects, with a mean value higher than the control group. The reduction in systolic function was related to altered loading conditions with a combination of reduced afterload and preload combined with augmented contractility. These altered myocardial mechanics appeared to be secondary to routine therapy with digitalis and diuretics. Diastolic function was also normal with differences in the rate of peak filling and rate of wall thinning entirely attributable to differences in ventricular size and function, and normalized indexes of diastolic function were not different between patients and controls. Patients evaluated late after repair were found to have normal regional wall motion with no evidence to suggest regional dysfunction as might be seen with regional ischemia. Ventricular size, wall thickness, systolic function, afterload, preload, contractility, and early diastolic function were indistinguishable from control values. Indexes of diastolic function demonstrated the same relation to age, body surface area, and ventricular size and function in both patients and controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗