Search PubMed⌕ Search

Biomedical subjects

A R Castaneda

Publications and source records attributed to A R Castaneda.

At least 109 records · Page 6Linked to original sources

Normothermic caval inflow occlusion. Application to operations for congenital heart disease.

The technique of normothermic caval inflow occlusion was introduced primarily for relief of pulmonary valve stenosis and continues to be used for this purpose with excellent results. However, the technique may also be applied to a number of other lesions such as aortic valve stenosis in neonates and infants, for placement of outflow patches or valve excision for pulmonary atresia with intact ventricular septum, for atrial septectomy in children with restrictive atrial septum, and for other conditions wherein a period of up to 2 minutes of intracardiac exposure is sufficient. This report examines the early and long-term results in 140 children who underwent normothermic caval inflow occlusion at The Children's Hospital, Boston, Massachusetts, over the past 11 years. Ninety-four children underwent pulmonary valvotomy (early mortality 0%), 21 had aortic valvotomy (19%), 10 with pulmonary atresia and intact ventricular septum underwent various procedures (50%), 11 had atrial septectomy (9%), and there were four miscellaneous procedures (50%). Apart from avoiding many of the potential complications of cardiopulmonary bypass, inflow occlusion has provided as good or better short-term and long-term results as those obtained with cardiopulmonary bypass, particularly in infants and neonates, and also has proved more cost effective.

Adolescent↗

Measurement of extravascular lung water in infants and children after cardiac surgery.

Extravascular lung water (EVLW) was measured in 17 patients with congenital heart disease by the cold-green-dye, double indicator-dilution technique. In 5 control patients, EVLW was 4.7 +/- 0.5 ml/kg (111 +/- 13 ml/m2) (mean +/- standard deviation). Twelve patients were studied immediately after correction of their heart defects. In 6 patients with normal or decreased pulmonary blood flow preoperatively (Group I), EVLW was 6.2 +/- 1.9 ml/kg (122 +/- 46 ml/m2). This value is not significantly different from that of the control patients. In 6 patients with increased pulmonary blood flow and congestive heart failure preoperatively (Group II), EVLW was 15.7 +/- 3.8 ml/kg (270 +/- 60 ml/m2), which is significantly different from both control and Group I patients (p less than 0.01). There was no correlation of EVLW with pre- or postoperative left atrial pressure, length of cardiopulmonary bypass or deep hypothermic circulatory arrest, postoperative serum protein, albumin, hematocrit or cardiac index. Thus, EVLW in the immediate postoperative period is determined by preoperative pathophysiologic characteristics rather than by intraoperative management, and patients with congestive heart failure resulting from left-to-right shunts have increased EVLW despite normal left atrial pressures.

Blood Pressure↗

Transposition of the great arteries and intact ventricular septum: anatomical repair in the neonate.

Fourteen neonates 18 hours to 32 days old with transposition of the great arteries (TGA) and virtually intact ventricular septum (IVS) underwent arterial switch operations under deep hypothermic circulatory arrest. Preoperative left ventricular to right ventricular peak systolic pressure ratios ranged from 0.7 to 1.0 (mean, 0.92), and the echocardiogram showed a centrally positioned ventricular septum in 10 patients and a rightward displaced ventricular septum in 4. One patient died twelve hours after operation. Postoperative complications included bleeding from the left coronary artery-pulmonary artery anastomosis (1 patient), stenosis of the pulmonary artery-aorta anastomosis requiring reoperation (2 patients), transient ST segment and T wave abnormalities consistent with ischemia (3), and development of pathological Q waves suggestive of clinically silent infarction (2). The capacity of the left ventricle in a neonate to effectively take over the systemic circulation was clearly demonstrated. A longer follow-up period is needed to assess late ventricular function, coronary ostial growth, growth of the aorta-pulmonary artery anastomosis, late aortic valve (anatomical pulmonary valve) function before definitive recommendations about the superiority of the arterial switch operation in neonates with TGA plus IVS can be formulated.

Aorta↗

Primary surgical closure of ventricular septal defect in the first year of life: results in 128 infants.

Between January 1973 and July 1981, 128 patients less than 1 year of age with failure to thrive, congestive heart failure or pulmonary artery hypertension underwent primary repair of a ventricular septal defect. The hospital mortality rate was 7.8% (10 of 128), and the late mortality rate was 2.3% (3 of 128). Mortality was highest among younger infants with preexisting respiratory problems or a hemodynamically significant residual lesion postoperatively. Complications included a large residual shunt in eight (6.2%), transient neurologic problems in five (3.9%) and persistent complete heart block in three (2.3%). Lung biopsy specimens obtained from 49 patients showed pulmonary vascular abnormalities in all. Complete right bundle branch block developed in 74 (64%) and bifascicular block appeared in 11 (9%). Recatheterization in 70 patients (55%) showed normal pulmonary artery pressures in all but 2 patients with a large residual shunt. Complete closure of the defect had been achieved in 49 (70%), and a hemodynamically insignificant shunt remained in 19 (27%). Patients without significant hemodynamic residua were asymptomatic and tended to accelerate in growth after surgery.

Age Factors↗

Is routine preoperative cardiac catheterization necessary before repair of secundum and sinus venosus atrial septal defects?

Between January 1976 and July 1983, 217 patients with atrial septal defect underwent surgical repair at Children's Hospital. Thirty with a primum atrial septal defect and 26 who underwent cardiac catheterization elsewhere before being seen were excluded from analysis. Of the 161 remaining patients, 52 (31%) underwent preoperative cardiac catheterization, 38 because the physical examination was considered atypical for a secundum atrial septal defect and 14 because of a preexisting routine indication. One hundred nine (69%) underwent surgery without catheterization, with the attending cardiologist relying on clinical examination alone in 5, additional technetium radionuclide angiocardiography in 5, M-mode echocardiography in 13 and two-dimensional echocardiography in 43; both M-mode echocardiography and radionuclide angiography were performed in 24 and two-dimensional echocardiography and radionuclide angiography in 19. Since 1976, there has been a trend toward a reduction in the use of catheterization and use of one rather than two noninvasive or semiinvasive techniques for the detection of atrial defects. Of the 52 patients who underwent catheterization, the correct anatomic diagnosis was made before catheterization in 47 (90%). Two patients with a sinus venosus defect and one each with a sinus venosus defect plus partial anomalous pulmonary venous connection, partial anomalous pulmonary venous connection without an atrial septal defect and a sinoseptal defect were missed. Of 109 patients without catheterization, a correct morphologic diagnosis was made before surgery in 92 (84%). Nine patients with a sinus venosus defect, three with sinus venous defect and partial anomolous pulmonary venous connection, four with partial anomalous pulmonary venous return without an atrial septal defect and one with a secundum defect were incorrectly diagnosed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Vascular structure in lung tissue obtained at biopsy correlated with pulmonary hemodynamic findings after repair of congenital heart defects.

At the time of surgical repair, a lung biopsy was performed on patients with congenital heart defects who either had pulmonary hypertension or in whom it would be likely to develop if the lesion were not corrected. Pulmonary vascular changes, assessed morphometrically and also according to the classification of Heath and Edwards (Circulation 18: 533, 1958), were correlated with the postoperative pulmonary hemodynamic findings: mean pulmonary arterial pressure the day after correction and mean pulmonary arterial pressure and pulmonary vascular resistance measured 1 year later. On the first postoperative day, increased mean pulmonary arterial pressure was uncommon in patients with morphometric grade A or B (mild) biopsy findings and Heath-Edwards grade N (normal), and if it was present it was of a mild degree. Mean pulmonary arterial pressure was commonly elevated in those with grade B (severe) or C (mild or severe) and Heath-Edwards grade I biopsy results and was more frequently elevated in those with grade II findings. Moderate-to-severe elevation of mean pulmonary arterial pressure was invariable in patients with Heath-Edwards grade III changes regardless of the morphometric grade. One year after repair, mean pulmonary arterial pressure and/or pulmonary vascular resistance were normal in all patients whose conditions were corrected surgically before 9 months of age regardless of the severity of the pulmonary vascular changes. Values were normal in patients whose conditions were repaired surgically at 9 months of age or later who had grade A or B (mild) morphometric findings with any Heath-Edwards grade or grade B (severe) morphometric findings with Heath-Edwards grade I but were increased in half of the patients with grade B (severe) morphometric findings and Heath-Edwards grade II or with grade C (mild or severe) and Heath-Edwards grade I or II changes. Pulmonary arterial pressure and pulmonary vascular resistance were increased in all patients whose conditions were repaired after 2 years of age with grade C morphometric findings and to a severe degree if associated with Heath-Edwards grade III. Thus, although the Heath-Edwards grade can usually be used to identify patients at risk for pulmonary hypertension in the early postoperative period, both the morphometric and the Heath-Edwards grades as well as the age of the patient at the time of repair can be used to determine whether pulmonary arterial pressure and resistance eventually return to normal or remain elevated.

Autopsy↗

Hemodynamic response to high-frequency ventilation in infants following cardiac surgery.

The hemodynamic response to high-frequency ventilation was compared with conventional ventilation in six infants following cardiac surgery. While undergoing high-frequency ventilation, adequate gas exchange was maintained in all infants. High frequency ventilation allowed a reduction of peak ventilatory pressure at the airway opening by 19%, and peak tracheal pressure by 42%. No clinically important changes in heart rate, systemic and pulmonary arterial pressure, cardiac index, or systemic and pulmonary vascular resistance were noted when high-frequency ventilation was compared with conventional ventilation.

Blood Pressure↗

Anesthetic complications in surgery for congenital heart disease.

Anesthetic complications in 500 consecutive operations for congenital heart disease were studied and their contribution to mortality and morbidity were assessed. The great majority of the cases were young and sick children in ASA Class III, IV, or V with complex congenital heart disease. Anesthetic mortality was zero and hospital mortality was 6.3%. Anesthetic complications occurred in 2% of the cases. Four major complications were seen, including two tension pneumothoraces, one episode of severe hypotension on induction, and a breathing circuit malfunction on induction leading to bradycardia and hypotension. Six minor complications included two cases of premature extubation that required reintubation postoperatively, one case of subglottic edema, airway obstruction from inadvertent tracheal insertion of an esophageal temperature probe, one corneal abrasion, and one case of erosion of the nasal ala secondary to a nasotracheal tube. Half of the complications were probably preventable, but the other half of the complications occurred despite specific attempts at their prevention.

Adjuvants, Anesthesia↗

Fixed subaortic stenosis in the young: medical and surgical course in 83 patients.

Eighty-three patients aged 11 months to 25 years were followed up a median of 6.1 years (range 8 days to 24 years) after diagnosis of fixed subaortic stenosis (SAS). Fourteen (17%) had significant noncardiac defects and 47 (57%) had additional cardiac malformations. The left ventricular (LV) outflow gradient increased in 25 of 26 patients catheterized more than once before surgery. Of 15 patients less than 12 years old with gradients less than or equal to 40 mm Hg, 10 ultimately underwent operation after developing severe obstruction; another has progressed to a gradient of 45 mm Hg at 6 years of age. Before surgery (at a median age of 12 years), 55% had aortic regurgitation (AR), which was usually mild. Infective endocarditis occurred in 12% of the group, with a frequency of 14.3 cases per 1,000 patient-years. Seventy-four patients were operated on, with 6 early (8%) and 7 late (9%) deaths. Twelve underwent reoperation to relieve residual obstruction. Surgery reduced gradients in patients with discrete SAS from 83 +/- 33 to 29 +/- 30 mm Hg, but in 6 patients with tunnel SAS the reduction was less satisfactory. AR was absent or mild in most patients postoperatively. When the gradient was reduced to less than 80 mm Hg, infective endocarditis did not occur unless there were other residual lesions. These data suggest that it is reasonable to resect discrete SAS in children less than 10 to 12 years old with LV outflow gradients greater than or equal to 30 mm Hg.

Adolescent↗

Two-dimensional echocardiographic assessment of caval and pulmonary venous pathways after the senning operation.

This study reports the 2-dimensional echocardiographic appearance of the caval and pulmonary venous pathways after the Senning procedure in 28 patients and establishes normal values for the caval and pulmonary venous pathway dimensions. Eighteen patients had no caval or pulmonary venous obstruction or tricuspid regurgitation at catheterization; 2 had isolated superior vena caval obstruction, 3 had isolated pulmonary venous obstruction, 4 patients had severe tricuspid regurgitation, and 1 had a large residual ventricular septal defect. The caval and pulmonary venous pathways were imaged in modified 4-chamber and transverse views, and the narrowest dimension of each pathway in each view was measured by 2 independent observers. Dimension measurements were then normalized to the cube root of body surface area. Caval and pulmonary venous pathway "dimension products" were obtained by multiplying the normalized dimension in the 4-chamber view by the normalized dimension in the transverse view. All patients with catheterization-proven caval or pulmonary venous obstruction or tricuspid regurgitation had caval or pulmonary venous pathway dimension products outside the normal range, defined by our measurements in the 18 patients with no caval or pulmonary venous obstruction or tricuspid regurgitation. Thus, 2-dimensional echocardiography can provide both quantitative and qualitative information about the caval and pulmonary venous pathways after the Senning procedure.

Child↗

Reoperation for isthmic coarctation of the aorta: follow-up of 26 patients.

Twenty-six patients underwent reoperation for coarctation of the aorta (C of A) between 1972 and 1980. Most patients (73%) had undergone primary repair in infancy. The interval to reoperation was 5 months to 18 years (mean 8.2 years). Indications for reoperation included symptoms in 4, exercise systemic hypertension in 1, electrocardiographic changes of left ventricular strain in 1, arm hypertension in 21, and a C of A gradient at rest greater than 30 mm Hg in all. Surgical procedures included patch aortoplasty (16 patients), bypass graft (6 patients), left subclavian angioplasty (3 patients), and end-to-end anastomosis (1 patient). There were no operative complications or mortality. There was 1 late death from aortic valve disease. Duration of follow-up in the remaining 25 patients was 2 weeks to 7 years (mean 2.5 years). All patients are asymptomatic. C of A gradients were significantly reduced from 30 to 132 mm Hg (mean 56) preoperatively to 0 to 48 mm Hg (mean 15) postoperatively. Right arm systolic blood pressure also was significantly improved from 120 to 237 mm Hg (mean 153) preoperatively to 100 to 160 mm Hg (mean 124) postoperatively. Systemic systolic hypertension persisted in 5 of 25 (20%). It is concluded that C of A reoperation is a low risk procedure that improves symptoms and reduces C of A gradient and arm blood pressure. However, systolic hypertension does not always resolve postoperatively. Patch aortoplasty appears to be a safe and effective surgical approach.

Adolescent↗

Subxyphoid 2-dimensional echocardiographic identification of left ventricular papillary muscle anomalies in complete common atrioventricular canal.

Mitral valve dysfunction is probably the major cause of operative mortality from total repair of complete common atrioventricular (AV) canal in infancy. The presence of a solitary left ventricular (LV) papillary muscle appears to be 1 anatomic factor influencing the success of mitral reconstruction because suturing of the cleft between the superior and inferior components of the anterior mitral leaflet creates a parachute mitral valve deformity, which may result in stenosis or in unduly high tension on the components of the repair. This study reports on (1) the 2-dimensional (2-D) echocardiographic appearance of the LV papillary muscle architecture in patients with complete common AV canal compared with that in normal subjects, and (2) the incidence of solitary LV papillary muscle in patients with complete common AV canal. Two-dimensional echocardiography was performed in 31 infants with complete common AV canal, 14 normal infants, and 9 infants with a large ventricular septal defect not involving the AV canal region. Of 31 infants with complete common AV canal, 26 (80%) had 2 LV papillary muscles on 2-D echocardiography, 3 (10%) had 3 LV papillary muscles, and 3 (10%) had 1 LV papillary muscle. In patients with 2 LV papillary muscles, the anterolateral papillary muscle was displaced posteriorly compared with that in normal subjects and in patients with ventricular septal defect, whereas the posteromedial papillary muscle was in its normal location. Among the 25 patients with complete common AV canal with 2 LV papillary muscles, there was 1 operative death. Among the 6 infants with complete common AV canal with LV papillary muscle anomalies, 5 underwent surgical repair with 4 early deaths. Subxyphoid 2-D echocardiography is a useful technique for evaluating LV papillary muscle architecture in complete common AV canal and permits identification of patients who may be at higher risk for unsuccessful mitral reconstruction.

Echocardiography↗

Transposition of the great arteries and ventricular septal defect: results with the Senning operation and closure of the ventricular septal defect in infants.

From May, 1978, to July, 1982, 46 infants ranging in age from 12 days to 12 months and in weight from 2.1 to 8.4 kg underwent repair of dextrotransposition of the great arteries (D-TGA) and ventricular septal defect (VSD) using a Senning repair and closure of the VSD. Ventricular septal defects were classified as membranous (47.8%), malaligned (28.3%), atrioventricular (AV) canal type (13.0%), subarterial (2.2%), muscular (2.2%), and multiple (6.5%). Hospital mortality was 15.2% and late mortality, 5.1%. Postoperative complications included tricuspid regurgitation (mild in 3 and severe, requiring tricuspid valve replacement, in 3), residual VSD (pulmonary/systemic flow ratio of greater than 2:1) in 3 patients (2, AV canal type and 1, multiple VSDs), pulmonary venous obstruction in 3 patients, and permanent complete heart block in 4 patients (2, AV canal type of VSD also requiring tricuspid valve replacement). Lung biopsy studies showed reversible Heath-Edwards and morphometric changes. No patient was seen with Heath-Edwards III or greater changes. In 10 patients, right ventricular end-diastolic pressures and pulmonary artery pressures at rest were within normal limits one year after operation. As the operative mortality of atrial inversion and arterial switch operations for D-TGA with VSD tends to become comparable, more extensive follow-up data, including cardiac catheterization and coronary arteriography in a large number of patients, will be necessary to establish the superiority of one approach over the other.

Abnormalities, Multiple↗

Reparative operations for interrupted aortic arch with ventricular septal defect.

From January, 1975, through September, 1982, 24 infants underwent primary or staged repair of interrupted aortic arch (IAA) with ventricular septal defect (VSD). Seven patients had IAA type A and 17 patients had type B. Eleven of the patients, median age 5 days, underwent staged operations and 13 infants, median age 6 days, underwent primary repair. Palliation was by tube graft interposition (six), subclavian-aortic anastomosis (three), left carotid-aortic anastomosis (one), or end-to-side aortic anastomosis (one) combined with pulmonary artery banding (eight) or early VSD closure. With palliation, there were three (27%) early deaths among the eleven patients and one (13%) late death among the eight remaining. Delayed repair at 5 days to 14 months (median 7 months) in seven patients incurred three (43%) early and no late deaths. Primary repair in 13 patients consisted of VSD closure combined with graft interposition (12) or end-to-side aortic anastomosis (one), with three (23%) early and no late deaths. Nine of 14 survivors had hemodynamic evaluation by catheterization 1 to 3 years following repair. None had a significant residual VSD or pressure gradients between the ascending and thoracic aorta. Six had subaortic stenosis, two mild (gradient less than 20 mm Hg) and four severe (gradient greater than 50 mm Hg), necessitating operation. Results of operations in neonates with IAA continue to improve. Essential in management is an awareness that subaortic stenosis and hypocalcemia may be accompaniments of this anomaly. Based on these data, we prefer primary repair for IAA with VSD.

Aorta, Thoracic↗

Management of infants with left ventricular outflow obstruction by conduit interposition between the ventricular apex and thoracic aorta.

On the basis of experience with older children, creation of a double-outlet ventricle by interposition of a valved conduit between the apex of the left ventricle and the thoracic aorta appeared to be an option for treating life-threatening left ventricular outflow tract obstruction even in the small heart of the infant. Over the recent 3 year period, nine infants ranging in age from 3 days to 13 months with various forms of left ventricular outflow tract obstruction underwent placement of an apical-aortic conduit to decompress the hypertensive left ventricle. There were two early and two late deaths. Five patients are clinically well and developing normally 5 to 23 months following the operation. This series demonstrates that this operation permits normal growth and development in infants previously failing to thrive. Echocardiographic and cardiac catheterization data suggest that left ventricular function need not be adversely affected by placement of a stent in the small infant ventricle; rather, ventricular function can be markedly improved. Although the mortality in this series is appreciable, it appears that apical-aortic conduit interposition can provide significant palliation for infants with otherwise lethal left ventricular outflow tract obstruction.

Aorta, Thoracic↗