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Biomedical subjects

T R Karl

Publications and source records attributed to T R Karl.

68 records · Page 4Linked to original sources
PubMed1992

Absent pulmonary valve syndrome: operation in infants with airway obstruction.

From 1979 through 1991, 19 infants with absent pulmonary valve syndrome and airway obstruction were seen for surgical treatment. All patients underwent extensive pulmonary artery aneurysmorrhaphy using cardiopulmonary bypass. Fourteen patients had simultaneous transatrial ventricular septal defect (VSD) closure, infundibular resection, and placement of a short transannular patch; 2 had transventricular VSD closure and infundibular resection without a transannular patch; 1 underwent transventricular VSD closure and transannular patching; and 2 underwent pulmonary artery aneurysmorrhaphy alone with the VSD left open. All 19 infants had good hemodynamics when taken from the operating theater, but 3 died postoperatively of severe airway obstruction, despite further tracheobronchopexy procedures in 2 (hospital mortality rate, 16%; confidence limits, 7% to 29%). Among the 16 patients discharged from the hospital, there was one late death. Five other patients have required reoperation for branch pulmonary artery stenosis (n = 2), residual airway obstruction resulting from persistent pulmonary artery dilatation (n = 1), closure of VSD (n = 1), and homograft valve insertion for pulmonary incompetence and right ventricular dysfunction (n = 1). There are 15 long-term survivors. Eight of them have episodic bronchospasm of mild to moderate severity, and all are responsive to sympathomimetic bronchodilator aerosols. The remaining 7 are asymptomatic.

Airway Obstruction↗
PubMed1992

Tetralogy of Fallot: favorable outcome of nonneonatal transatrial, transpulmonary repair.

This report describes our experience with 366 patients who had a transatrial, transpulmonary repair of tetralogy of Fallot between December 1980 and December 1991. Included in this group are patients with tetralogy of Fallot plus atrioventricular septal defect as well as patients displaying all degrees of aortic override (in the presence of subaortic ventricular septal defect and right ventricular outflow tract obstruction). Median age was 15.3 months and median weight, 12.3 kg. Of the 366 patients, 72% required a pericardial patch to reconstruct the main pulmonary artery or right ventricular outflow tract. Serious coronary anomalies were seen in 11 patients, without influencing surgical approach. There were two hospital deaths (0.5%; 70% confidence limits, 0.2% to 1.2%). Actuarial survival was 97.5% at 42 months (95% confidence limits, 95% to 99%) reflecting four late deaths over 1,129 patient-years of follow-up. Postoperative cardiac catheterization studies were performed in 61 patients at a mean follow-up interval of 23 months. Mean right ventricular/left ventricular systolic pressure ratio after repair was 0.46 (standard deviation, 0.28), and mean gradient across the right ventricular outflow tract was 15 mm Hg (standard deviation, 24 mm Hg). Actuarial freedom from reoperation for any reason has been 95% (95% confidence limits, 92% to 97%) at 5-year and 10-year follow-up. These early and medium-term results encourage us to continue with transatrial, transpulmonary repair of tetralogy of Fallot. We believe that this approach has an operative risk similar to or lower than transventricular repair, and that it will result in better preservation of right ventricular function in the long term.

Child, Preschool↗
PubMed1992

Repair of hypoplastic or interrupted aortic arch via sternotomy.

Herein we describe our experience with repair of interrupted aortic arch and coarctation plus hypoplastic aortic arch in 55 consecutive infants (1984 to 1990). Median age at operation was 6 days and median weight 3.1 kg. Associated severe intracardiac anomalies were the rule. All patients had significant congestive cardiac failure, and the majority required prostaglandin E1 resuscitation and inotropic support (with or without ventilation) before the operation. All operations were performed via sternotomy with core cooling and circulatory arrest. Isolated myocardial perfusion was used in 13 patients during arch repair. A complete intracardiac (biventricular) repair was performed except in patients expected to require a Fontan operation as definitive treatment. The operative mortality overall was 14.5% (confidence limits 10% to 22%). For arch repair plus biventricular intracardiac repair, the operative mortality was 9% (confidence limits 5% to 15%), and for arch repair plus palliative intracardiac repair, 40% (confidence limits 22% to 60%). The mortality in the isolated myocardial perfusion group was 0% (confidence limits 0% to 14%), which may be related to reduced myocardial ischemic time (p less than 0.05). Actuarial survival was 75% (confidence limits 65% to 83%) at 12 months, with no subsequent deaths over 1294 patient-months (mean 28 months) of follow-up. Actuarial freedom from recurrent arch obstruction was 69% (confidence limits 48% to 85%) at 46 months' follow-up. Primary repair of interrupted aortic arch and coarctation plus hypoplastic arch compares favorably with a staged approach and is recommended even when complex intracardiac anatomy is present.

Aorta, Thoracic↗
PubMed1991

Operations for subaortic stenosis in univentricular hearts.

Optimal prevention and treatment of subaortic stenosis (SAS) in the univentricular heart with subaortic outlet chamber and high pulmonary blood flow remains controversial, especially when complicated by aortic arch obstruction. Herein we analyze our surgical results. Group 1 consisted of 11 infants (mean age, 10 days) with univentricular heart and SAS. Ten required repair of interrupted aortic arch (n = 7) or coarctation with hypoplastic arch (n = 7). Four patients had relief of SAS by either Damus-Kaye-Stansel connection (n = 2) or aortopulmonary window (n = 2), with three operative deaths and one late death. Six had one-stage arterial switch and atrial septectomy with arch repair (5/6) with one operative death and one late death. Two survivors have progressed to bidirectional cavopulmonary shunt, a third has had a Fontan operation, and a fourth awaits Fontan. In group 2, 11 children required operation for acquired SAS after pulmonary artery banding. Nine have progressed to Fontan operation with either staged (n = 3) or concurrent (n = 6) relief of SAS by Damus-Kaye-Stansel connection or subaortic resection. Fontan mortality was 11% (70% confidence limits, 2% to 32%). Group 3 consisted of 3 patients without pulmonary artery banding who had SAS diagnosed at Fontan evaluation. All 3 survived Fontan operation and relief of SAS by Damus-Kaye-Stansel connection or subaortic resection. Group 4 consisted of 1 patient with previous pulmonary artery banding (no SAS) who underwent Fontan operation but required Damus-Kaye-Stansel connection 30 months later for SAS.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormalities, Multiple↗
PubMed1991

Very small pulmonary arteries: central end-to-side shunt.

Between 1980 and 1989, 28 patients with pulmonary atresia, ventricular septal defect, and very small pulmonary arteries with major aortopulmonary collateral arteries underwent direct central end-to-side shunts as staging procedures. Age range was 2 months to 32 years, with 19 patients less than 1 year of age. Pulmonary artery diameters ranged from 1 to 4 mm, with 24 less than 3 mm. Two patients (7%; 70% confidence limits, 2% to 16%) died after the shunt, and there were two further deaths after subsequent staging or correction. Acute shunt complications included congestive cardiac failure (mild to moderate, n = 8; severe, n = 3) and endocarditis (n = 1). Proximal right pulmonary artery stenoses have occurred in 75% of patients and left pulmonary artery stenoses, in 50%. Satisfactory pulmonary artery growth was achieved, however, in 16 of 24 hospital survivors investigated postoperatively. Twelve patients have proceeded through unifocalization to biventricular repair (in 2 the ventricular septal defect patch was subsequently fenestrated) with one death (8.3%; 70% confidence limits, 1% to 25%). Eight patients are still in staging, and 4 have been excluded from the program because of inadequate unifocalization. The direct central end-to-side shunt has proven satisfactory in attaining pulmonary artery growth in patients with very small central pulmonary arteries.

Adult↗
PubMed1991

Extracardiac valved conduits in the pulmonary circuit.

Extracardiac valved conduits represent one of the weakest facets of reconstructive surgery for congenital heart disease in that they invariably need to be replaced because of growth of the patient or because of valve or conduit failure. Between 1979 and 1989, 141 patients had 169 valved conduits placed between the heart and the pulmonary artery circuit. There were 81 male and 60 female patients, aged 2 days to 35 years (mean age, 5.9 years), with 46 patients less than 1 year of age. We performed primary repair in 117 patients; in this group, there have been 28 conduit replacements in 27 patients. In 17 patients initial repair with a conduit was performed elsewhere and we replaced these conduits in 15 and removed them in 2. A further group of 9 patients were seen after repair of tetralogy of Fallot or double-outlet right ventricle, with severe pulmonary incompetence or right ventricular outflow tract aneurysm. All had valved conduits inserted as secondary procedures. The types of valved conduits used were xenograft (n = 126) and homograft (n = 43). There were six hospital deaths (3.6%; 70% confidence limits [CL], 2% to 6%) and seven late deaths (4.1%; CL, 2.5% to 6.5%) in a total of 169 conduit insertions. Forty-five conduits have been removed and 43 reinserted without early or late mortality (0%; CL, 0% to 4%). Actuarial survival after conduit insertion was 87% at 5 years (CL, 80% to 92%), including operative mortality. Actuarial freedom from conduit replacement was 37% at 5 years (CL, 20% to 56%). Conduit insertion in infants and small children ensures subsequent replacement, but this can be done at low risk.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Centrifugal pump left heart assist in pediatric cardiac operations. Indication, technique, and results.

Twelve children aged 6 days to 12 years had left or common atrial to aortic extracorporeal support with a centrifugal pump after cardiac operations. Left ventricular assist time ranged from 38 to 190 hours. Ten patients were successfully weaned from left ventricular assist device support; four hospital deaths occurred afterward. All six survivors were discharged from the hospital with improved left ventricular function. Although the follow-up time is short and the experience limited, we consider the centrifugal pump type of left ventricular assist device to be a potentially lifesaving treatment modality for selected pediatric patients having cardiac operations.

Cardiac Output, Low↗
PubMed1990

Critical aortic stenosis in the first month of life: surgical results in 26 infants.

Between 1980 and 1989, 26 infants aged less than 1 month underwent open aortic valvotomy for critical aortic stenosis. All had congestive heart failure requiring inotropic agents (58%), ventilation (42%), and/or prostaglandin E1 (35%) preoperatively. Nine patients with isolated aortic stenosis had an operative mortality of 0%, whereas 17 patients with other anatomical lesions had a 47% mortality (p less than 0.01). Univariate analysis failed to identify additional risk factors other than year of operation (p less than 0.05). There were four late deaths, three probably related to arrhythmia (actuarial survival at 113 months = 0.53). Two patients have required late reoperation; neither required valve replacement.

Actuarial Analysis↗
PubMed1989

Left heart assist for ischemic postoperative ventricular dysfunction in an infant with anomalous left coronary artery.

A baby weighing 6.2 kg with anomalous origin of the left coronary artery from the pulmonary artery developed profound left ventricular failure during surgical repair. He was supported for 41 hours with centrifugal pump left heart assist. Recovery following cessation of ventricular assist was uneventful and ventricular function was improved compared to preoperative status.

Cardiac Output, Low↗
PubMed1988

A technique for concurrent repair of pectus excavatum and intracardiac defects.

Pectus excavatum deformity may present problems when median sternotomy is required for repair of intracardiac defects. We have used a partial median sternotomy extending from the manubrium to the level of the second intercostal space with extension into that space. The perichondral sheaths are disconnected from the sternum on the right side after removing the deformed costal cartilages. Exposure is thus provided for the cardiac procedure. Following this, the upper sternal fragments are sutured together and the repair is completed in a manner similar to the Ravitch technique.

Funnel Chest↗
PubMed1986

Surgical treatment of absent pulmonary valve syndrome.

The absent pulmonary valve syndrome includes agenesis of the pulmonary valve, annular stenosis, and pulmonary insufficiency. The pulmonary arteries are aneurysmal and usually compress the tracheobronchial tree. These features are associated with a ventricular septal defect and right ventricular hypertrophy. Nineteen children aged 5 days to 11 years were treated between 1976 and 1983. Nine were younger than 1 year. Intractable respiratory symptoms and heart failure were the main features in the infant group; five required preoperative assisted ventilation. Older children had decreased exercise tolerance and repeated respiratory infections. Several surgical techniques were used in this series. The best results were achieved when the size of the main, right, and left pulmonary arteries was reduced by extensive anterior resection; the ventricular septal defect was closed; and an aortic homograft was interposed between the right ventricle and the pulmonary artery. Four infants and four children treated in this way survived the operation. Five of the nine operated infants died (56%); all older children survived the operation. At follow-up, six children were asymptomatic and one was in New York Heart Association Class II. All four infants were progressing satisfactorily although all had some residual pulmonary symptoms. Closure of the ventricular septal defect, reduction of the size of the pulmonary arteries, and insertion of an aortic homograft was the optimal treatment in our series.

Aneurysm↗
PubMed1983

Zollinger-Ellison syndrome with esophagitis and Barrett mucosa.

Although esophageal disease in Zollinger-Ellison syndrome is being recognized with increasing frequency, Barrett esophagus is seen only rarely. Basal lower esophageal sphincter pressure is probably not different in Zollinger-Ellison syndrome and non-Zollinger-Ellison syndrome patients. Circulating gastrin, therefore, cannot be the major determinant of lower esophageal sphincter pressure in vivo. Total gastrectomy and resection of all metaplastic esophagus, when feasible, is the treatment of choice for patients with Zollinger-Ellison syndrome and Barrett mucosa.

Barrett Esophagus↗