Donald R. Fischer

Carotid artery approach for balloon dilation of aortic valve stenosis in the neonate: A preliminary report

Balloon valvuloplasty in neonates with severe aortic valve stenosis is limited by difficulties in catheter manipulation around the arch and across the valve and by the risk of femoral artery complications. A right common carotid artery cutdown was utilized for balloon aortic valvuloplasty in five neonates 1 to 20 days of age, weighing 3.1 to 3.9 kg. Standard balloon valvuloplasty was performed through a 6F sheath inserted in the right carotid artery. The arteriotomy was repaired at the end of the procedure. Mean left ventricular systolic pressure was reduced from 142 to 97 mm Hg, with a decrease in mean peak systolic pressure gradient from 76 to 33 mm Hg. Only one patient developed mild aortic regurgitation. One patient with a hypoplastic left ventricle died, and one patient required open valvotomy. All four survivors have a normal carotid pulse and no neurologic sequelae. Two of these patients required repeat balloon dilation to treat residual aortic valve stenosis at 8 and 10 months of age, respectively. Balloon valvuloplasty using a carotid artery approach is feasible and was safe in five neonates with severe aortic valve stenosis.

Extracorporeal membrane oxygenation for postcardiotomy cardiogenic shock in children

Size limitations and technical barriers prohibit the use of many conventional mechanical circulatory support systems for postcardiotomy ventricular dysfunction in pediatric populations. Extracorporeal membrane oxygenation (ECMO), frequently used to treat neonatal respiratory failure, can provide cardiac support and is effective treatment of postoperative myocardial failure in children. From 1981 to 1987, 10 patients aged 2 days to 5 years were maintained on ECMO for 15 to 144 hours (mean duration, 92 +/- 16 hours) after cardiotomy. Operative procedures included repair of tetralogy of Fallot (2 patients), closure of a ventricular septal defect (2), the Senning procedure for transposition of the great arteries (1 patient), repair of interrupted aortic arch with closure of a ventricular septal defect (1), repair of a partial atrioventricular septal defect (2), closure of a ventricular septal defect with excision of an anomalous muscle bundle (1), and the Fontan procedure (1). Venoarterial ECMO was established in all 10 children. Six patients underwent transthoracic right atrium-ascending aorta cannulation, 3 had right internal jugular vein-right common carotid artery cannulation through a cervical incision, and 1 had right internal jugular vein-left axillary artery cannulation. Eight of the 10 patients were successfully weaned from ECMO, and 7 are long-term survivors. There were 3 deaths; 1 was caused by cardiac and acute renal failure complicated by sepsis two days after decannulation, another occurred 19 days after atrioventricular septal defect repair, and 1 was caused by massive pulmonary hemorrhage. Major hemorrhage developed in 3 patients while on ECMO; 2 required premature decannulation for mediastinal bleeding from operative sites and ultimately survived, and 1 died of respiratory failure as a result of endobronchial bleeding. We conclude that the use of ECMO in pediatric populations for transient postoperative ventricular dysfunction improves survival with limited overall morbidity.

Tetralogy of Fallot with absent pulmonic valve: analysis of 17 patients.

Seventeen patients with tetralogy of Fallot (TF) and absent pulmonic valve were seen at Childrens Hospital of Pittsburgh from 1958 to 1981. In 7 patients, severe respiratory symptoms developed due to bronchial compression by an aneurysmal pulmonary artery, and 6 died. In 4 patients, moderate respiratory symptoms developed. Six patients remained free of respiratory distress. Medical and surgical management of patients with respiratory distress in infancy has been frustrating and frequently unsuccessful. A 4-month-old infant with respiratory distress underwent complete intracardiac repair with valve insertion and has subsequently survived with relief of symptoms. Considering the high mortality rate in this group of patients, further attempts at aggressive surgical repair in infancy for patients with severe respiratory symptoms is warranted. An anatomic review of pathologic specimens with this anomaly confirmed previous reports of the frequent association of absence of the ductus arteriosus in patients with tetralogy of Fallot and absent pulmonary valve. The exception is noted in patients with discontinuity between the right and left pulmonary arteries in which a ductus arteriosus may be present supplying the isolated left pulmonary artery.

Ventricular septal defect associated with aneurysm of the membranous septum

The most common variety of ventricular septal defect, a perimembranous defect, is frequently associated with a so-called aneurysm of the membranous septum. Previous studies have suggested that ventricular septal defects associated with an aneurysm of the membranous septum tend to spontaneously decrease in size or close more than defects without such an aneurysm. To better define the natural history of this entity, clinical and catheterization data from 87 patients with ventricular septal defect and aneurysm of the membranous septum were reviewed. The initial evaluation was made at a median age of 0.3 years (range 0.1 to 11), with the final evaluation at a median age of 10 years (range 1.5 to 20) and a median duration of follow-up of 8.6 years (range 1.2 to 18.8). Approximately 75% of the ventricular septal defects had a small or no left to right shunt at last evaluation. Overall, 48 patients (55%) had no significant change in the size of the defect, and 39 (45%) showed improvement during the period of observation. Only four patients (5%) had spontaneous closure of the defect. Of the 49 patients who presented with a large left to right shunt, with or without congestive heart failure, 23 (47%) had persistence of a shunt large enough to warrant surgery. When spontaneous improvement occurred, it did so by 6 years of age in all but one patient. Therefore, a continued tendency for a ventricular septal defect associated with an aneurysm of the membranous septum to spontaneously decrease in size or close after this age may be less likely than previously suggested.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemodynamic function after the mustard operation for transposition of the great arteries

Pre- and postoperative cardiac catheterization data and cinenangiocardiograms of 82 patients who survived the Mustard operation for transposition of the great arteries (TGA) were reviewed. The post-operative catheterizations were performed 20 days to 10 years after operation (mean 2.5 years). Forty-six patients (56%) had no or insignificant associated cardiac lesions, whereas 36 (44%) had ventricular septal defect, pulmonary stenosis, or both, and required surgical intervention at the time of the Mustard operation. Postoperatively, 11 patients (13%) had significant systemic venous obstruction. Of the 11 patients, 6 required reoperation, and 2 patients had evidence of restenosis or complete obstruction in the superior vena cava after reoperation. In most patients, superior vena caval obstruction was well tolerated even in the presence of high pressure in the superior vena cava. Pulmonary venous obstruction occurred in 5 patients (6%), 3 of whom had no clinical symptoms despite severe pulmonary venous obstruction, although all had radiographic evidence of pulmonary venous congestion. The incidence of obstruction was drastically reduced after the Mustard operation was modified to include routine enlargement of the pulmonary venous atrium. Tricuspid regurgitation was uncommon (10%), but did occur in patients who had transatrial closure of a ventricular septal defect. Preoperatively, left ventricular outflow obstruction occurred in 38%. In 12 patients an attempt was made to relieve the obstruction at surgery. The 6 patients who had localized obstruction had a good result, but patients with more diffuse narrowing of left ventricular outflow had little or no relief of obstruction. Mild to moderate left ventricular outflow gradients regressed spontaneously in most patients after the Mustard operation.

Echocardiographic findings before and after liver transplantation

Echocardiographic studies were performed in 73 patients with various types of chronic liver disease. They were 0.5 to 19 years old (mean 5). Thirteen patients underwent follow-up echocardiography 1 to 13 months (mean 6) after liver transplantation. Preoperatively 60 patients (82%) showed evidence of high cardiac output (cardiac index greater than 4 liters/min/m2); these patients manifested increased left ventricular (LV) and left atrial dimensions and a thickened LV posterior wall. Transvenous contrast echocardiographic study confirmed the presence of intrapulmonary arteriovenous shunting in 4 patients. Studies after liver transplantation revealed a reduced LV end-diastolic dimension in 12 patients. Cardiac index was reduced a mean of 35% after transplantation (p less than 0.001). This study suggests that liver transplantation improves common hemodynamic abnormalities in chronic liver disease.

Exercise studies after the mustard operation in transposition of the great arteries

Twenty-one postoperative patients with transposition of the great arteries (TGA) underwent graded exercise testing 4 to 15 years (mean 9) after the Mustard operation. No patient had subjective exercise intolerance before testing, although some had symptomatic resting arrhythmias. Correlations were made between cardiac catheterization data and 24-hour ambulatory monitoring. Exercise tolerance was diminished in nearly half of the patients. No statistically significant differences were found in heart rate or blood pressure responses, but maximal oxygen consumption values were lower than the control values (p less than 0.001) in the larger patients. Arrhythmias were present or provoked in most patients during exercise testing. Only 28% remained in normal sinus rhythm during and after exercise. Multifocal premature contractions were the most serious arrhythmias demonstrated. Some long-term survivors of the Mustard operation may have abnormal exercise dynamics, even though they may be asymptomatic and have normal physical activities and endurance. Mean maximal systolic blood pressure, heart rate, oxygen consumption, and maximal treadmill times were consistently in the low-normal range or were statistically lower than normal.

Arrhythmias in transposition of the great arteries after the mustard operation

Disorders of rhythm or conduction in patients with transposition of the great arteries (TGA) after the Mustard operation have been widely reported. This study provides a systematic evaluation of the electrophysiologic function of 87 survivors of the Mustard operation at a single institution. Surface electrocardiograms were reviewed in all 87 patients, Holter monitoring data in 26 patients, exercise electrocardiograms in 21 patients, and invasive electrophysiologic data in 61 patients. Surface electrocardiograms showed normal sinus rhythm in 52%, sinus node dysfunction in 27%, and atrioventricular block in 16%. Holter monitoring was obtained in an unselected subgroup of 26 patients who had a mean age of 12 years and a mean interval from operation of 9 years. Sinus node dysfunction was found in 58%, atrioventricular block in 27% ventricular ectopy in 50%, supraventricular ectopy in 27%, and no abnormalities in only 8%. Intracardiac electrophysiologic evaluation showed a high frequency of abnormal sinus node recovery times and suboptimal response of the atrioventricular-conduction system to rapid atrial pacing. When all modalities used in this study were considered, sinus node dysfunction occurred in 47%, ectopy in 34% and atrioventricular block in 23%. Although only 30% of patients had no evidence of arrhythmia, symptoms of rhythm or conduction disturbances were rare.

Unilateral pulmonary vein atresia: Clinical and radiographic spectrum

SummaryThree cases of unilateral pulmonary vein atresia are presented to illustrate part of the clinical and radiographic spectrum of this anomaly. One patient had major associated cardiovascular abnormalities and pulmonary hypertension, one had recurrent hemoptysis, and the other patient was asymptomatic with normal pulmonary artery pressure and no associated abnormalities. In one case, serial catheterizations indicated that the pulmonary vein atresia was acquired. This report stresses the radiographic, hemodynamic, and angiographic findings in patients with unilateral severe pulmonary venous obstruction. The embryology, pathology, and surgical approach are also discussed. The diagnosis should be strongly suspected before cardiac catheterization when typical features are present on the chest radiograph and isotopic ventilation perfusion scan.

Cardiac catheterization in children on extracorporeal membrane oxygenation

There are limited reports in the literature that address the unique issues related to cardiac catheterization on extracorporeal membrane oxygenation. Since 1990, cardiac catheterization has been performed on nine patients on extracorporeal membrane oxygenation. The median age was 10 months (range four days to 18 years) and the median weight was 4 kg (range 2.3–73.8 kg). The indications for catheterization were to relieve pulmonary edema in five patients with severe left ventricular dysfunction, and in one instance each, evaluation of probable anomalous left coronary artery, tetralogy of Fallot associated with a diaphragmatic hernia, possible pulmonary venous abnormalities, and postoperative evaluation after an arterial switch. Venous access was obtained through a preexisting femoral venous line in six patients, and through a cutdown of the saphenous or femoral vein in the other three. Interventional catheterization procedures were performed in six of the nine patients in this group. These consisted of blade atrial septostomy followed by balloon septostomy or dilation of the atrial septum in four patients, balloon septostomy alone in one, and placement of a catheter from the left atrium to the circuit used for extracorporeal oxygenation in another. A transseptal puncture was performed in five of them. Adequate decompression of the left atrium with relief of pulmonary edema was achieved in five patients. Six of the nine children in this group died, although there were no complications or deaths related to the catheterization. Children in cardiopulmonary failure on extracorporeal support represent a population at high risk. Diagnostic cardiac catheterization and atrial septostomy to decompress the left heart, when indicated, can be performed safely in such patients.