Lily George

Balloon dilatation of porcine bioprosthetic valves in the pulmonary position.

Balloon dilatation (BD) of bioprosthetic valves was investigated in vivo and in vitro. Four children with stenotic bioprosthetic porcine valves in the pulmonary position underwent BD of the valve 10 to 24 months after its insertion. Average valve gradient was reduced from 47.5 to 27 mm Hg. Obstruction at the conduit-branch pulmonary artery connection became apparent after dilatation of the valve. These distal stenoses were also dilated. BD technique was tested in vitro with the use of nonstenotic valves in fresh conduits. No damage to the valve or to the conduit was found when oversized balloons were used in a standard fashion or intentionally inflated until rupture. It is concluded that conduit replacement may be deferred by balloon dilatation of obstructed biological valves and/or a stenotic conduit-pulmonary artery anastomosis.

Percutaneous use of stents to correct pulmonary artery stenosis in young children after cavopulmonary anastomosis

Pulmonary artery distortion is a risk factor among candidates for the Fontan procedure. In 57 patients evaluated by catheterization after successful cavopulmonary anastomosis, 8 had proximal left pulmonary artery (LPA) stenosis, either discrete (4 patients) or long segment (4 patients). Median age was 27 months (range 19 to 60 months). Median weight was 11.4 kg (range 9.1 to 20.0). Mean diameter at LPA stenosis was 4.4 +/- 0.4. Proximal right pulmonary artery mean diameter was 10.4 +/- 1.0 mm. After angiographic and hemodynamic assessment, short 11F sheaths were placed in the right internal jugular (6 patients) or subclavian veins (2 patients). Pulmonary artery angioplasty and stent placement were performed. LPA stenoses were enlarged using 10 Palmaz stents dilated to 10 mm (7 patients) or to 12 mm (3 patients). Poststent angiograms showed that narrowest LPA dimensions were significantly enlarged to 9.9 mm +/- 1.0 mm, p < 001). There were no complications. Follow-up studies (catheterizations in 4 patients, echocardiograms in 8 patients) were performed 4 to 9 months after stent implantation. No restenosis was observed. Five patients had completion of their Fontan procedures; three patients are pending Fontan completion. This study demonstrates the efficacy and safety of the percutaneous use of Palmaz stents to correct pulmonary artery stenosis in young children after cavopulmonary anastomosis.

Surgical closure of the tricuspid valve for pulmonary atresia, intact ventricular septum, and right ventricle to coronary artery communications

SummaryA surgical approach is reported for a patient with pulmonary atresia, intact ventricular septum, and right ventricle to coronary artery communications through sinusoids. A shunt procedure was performed at two days of age; the right ventricular outflow tract was not opened. At subsequent catheterization, the tricuspid valve was temporarily closed with a balloon catheter and no change was seen in the ECG. At five months of age, the right ventricle was plicated and a patch was sewn over the tricuspid valve. One year after surgery, neither the right ventricular cavity nor the sinusoids could be demonstrated at angiocardiography; ECG changes of left ventricular ischemia have resolved, and the child is growing normally.

The Damus-Fontan procedure

The Damus-Kaye-Stansel operation is a useful technique for the treatment of complex cyanotic congenital heart disease when there is obstruction between the systemic ventricle and the aorta. Modifications of the technique include transection of the aorta and the pulmonary artery, anastomosis of the contiguous aortic and pulmonary walls, and connection of the distal aorta to the perimeter of the new bivalved proximal great artery. In addition, the bidirectional cavopulmonary shunt technique can be used with or without the Fontan procedure. Six patients underwent a Damus-Fontan operation, and all survived. Two patients underwent the Damus-cavopulmonary shunt (hemi-Fontan) procedure, and 1 survived. The postoperative status of the 7 survivors is good to excellent. Follow-up ranges from 2 months to 7 1/2 years.

Congenital heart disease and pulmonary artery hypertension. I. pulmonary vasoreactivity to 15% oxygen before and after surgery

Pulmonary vasoreactivity at sea level was studied in 22 children before and in 15 children after corrective cardiac surgery for congenital heart disease and pulmonary artery hypertension; 8 children were studied both before and after cardiac surgery. During cardiac catheterization in 28 children, pulmonary and systemic hemodynamics were determined in room air and during breathing of 15% oxygen, which corresponds to a maximal hypoxic level commonly encountered during airplane travel. Before surgery, 19 of 22 children tolerated 15% oxygen (O2), which caused the following hemodynamic changes from room air status: the ratio of pulmonary to systemic arterial pressure increased from 0.70 to 0.78 (p less than 0.05), the ratio of pulmonary to systemic flow decreased from 2.2 to 2.0 (p greater than 0.05) and the ratio of pulmonary to systemic vascular resistance increased from 0.33 to 0.40 (p less than 0.02). In two children, severe pulmonary vasoconstriction developed within 5 minutes of 15% oxygen administration, requiring immediate discontinuation of hypoxia; neither patient had lasting deleterious effects. There was no evidence of increased pulmonary vasoreactivity in children with Downs syndrome compared with genetically normal children. After corrective surgery in 15 children (including both of the hyperreactors), no significant pulmonary vascular response to 15% oxygen was found. It is concluded that, in a small number of children with unrepaired congenital heart disease and pulmonary artery hypertension, pulmonary vascular hyperreactivity can be induced by breathing 15% oxygen; this reaction is life-threatening but reversible with the administration of 100% oxygen.(ABSTRACT TRUNCATED AT 250 WORDS)

Umbilical vascular catheters: localization by two-dimensional echocardio/aortography.

SummaryUmbilical vascular catheters are often necessary in the care of critically ill neonates. Position of the catheter tip is usually determined by roentgenography. Location of the umbilical arterial or venous catheter was determined by 2-dimensional echocardio/aortography in 55 consecutive infants and was compared to localization by thoraco-abdominal roentgenography. Most of the infants (76%) had respiratory distress syndrome or congenital heart disease.Echoaortographic localization of the umbilical arterial catheter correlated very closely (N = 50, r = .90) with roentgenographic determination. For localization of the tip of the umbilical venous catheters, echocardiography was more accurate than roentgenography (employing contrast echocardiography for confirmation of cardiac chamber position).Two-dimensional echocardio/aortographic localization of the tip of indwelling umbilical vascular catheters is as accurate as roentgenography in the arterial system and more accurate than x-ray for umbilical venous catheters. Echocardio/aortography is superior to roentgenography (in localizing the catheter tip) because it 1) avoids ionizing radiation, 2) makes positioning of the patient unnecessary, 3) allows visualization of the catheter in relation to cardiovascular structures, and 4) may allow demonstration of intraarterial thrombo-emboli.

Partial anomalous left pulmonary artery: new evidence on the development of the pulmonary artery sling.

Clinical and angiographic data of a child with a unique form of partial anomalous left pulmonary artery are reported. Because the anomalous pulmonary artery does not run posterior to the trachea, this malformation is not associated with airway obstruction, as are all other forms of anomalous left pulmonary artery described to date. This case strengthens our understanding of the development of the pulmonary artery sling.

Shared coronary arteries and coronary venous drainage in thoracopagus twins

A pair of type B thoracopagus twins with complex cyanotic heart disease had shared coronary arteries and coronary venous drainage. Surgical separation was not attempted and the twins died at 10.5 months of age. Antemortem angiography demonstrated that Twin As right coronary artery supplied Twin Bs diaphragmatic and anterior ventricular myocardial free wall. A midline communication existed between each twins right atrium at a common coronary sinus. The crossing coronary artery coursed alongside this connection and was visualized echocardiographically. At postmortem examination, the great cardiac vein of Twin A drained into the orifice of the common coronary sinus on Twin Bs side of the midline. In five of six previously reported cases, the children died at attempted separation shortly after ligation of the interatrial communication. This may have been because of occlusion of a coronary artery or acute obstruction of a coronary vein. Consideration of separation of type B thoracopagus twins requires anatomic delineation of the coronary arteries and veins.