Transcatheter occlusion of large pulmonary arteriovenous fistula.

We describe the compound transcatheter occlusion of a large and symptomatic pulmonary arteriovenous malformation in a 58-yr-old man. Pre- and postintervention clinical and laboratory data support the impression of an excellent outcome.

Significant pulmonary valve incompetence following oversize balloon pulmonary valveplasty in small infants: A long-term follow-up study.

Oversized dilatation balloons are recommended for relief of valvar pulmonic stenosis in infants and children during cardiac catheterization. Little information exists about the long-term outcome of this practice. Six of 107 consecutive patients undergoing balloon pulmonary valveplasty developed increasing pulmonary valve incompetence during follow-up periods of 0.5-10 years (mean, 7.2 years). Secondary right ventricular dilatation prompted insertion of a bioprosthetic pulmonary valve in one patient 6.8 years after intervention; valve replacement is pending in two additional patients, 4.3 and 10 years after intervention, respectively; and the three remaining subjects are thought likely to require valve replacement during childhood. The six reported subjects differ from the pulmonary valveplasty group as a whole in that they are younger (median age, 3 days vs. 11 months), had a higher degree of obstruction (right/left ventricular systolic pressure ratio prior to valveplasty 1.28 vs. 0.92), and underwent dilatation with relatively oversized balloons (balloon diameter to pulmonary valve annulus ratio 1.44 vs. 1.08). The balloon diameter to valve annulus ratio did not exceed 1.5 in any subject. Caution is advised in the use of oversized dilatation balloons in neonates or young infants with severe or critical pulmonic stenosis. Long-term consequences of substantial pulmonary valve incompetence outweigh, in our opinion, the limited gradient relief achieved with smaller balloons, sometimes requiring a second dilatation of the valve at an older age and larger size. Cathet. Cardiovasc. Intervent. 48:61-65, 1999.

Vessel-sparing technique for coil occlusion of the very small patent ductus arteriosus.

A technique is described for coil occlusion of the small patent ductus arteriosus through a 4 French arterial catheter. The need for a 5 French sheath and catheter to stabilize the 3 French size delivery catheter system is obviated. The method is proposed as a way to minimize arterial vascular injury in the small patient undergoing transcatheter occlusion of the small ductus.

Great vein and right atrial thrombosis in critically ill infants and children with central venous lines.

We performed a retrospective review of echocardiographic data files of infants and children hospitalized in the Newborn and Pediatric Intensive Care Units. Echocardiograms were examined to detect the presence and evolution of great vein and right atrial thrombosis in patients with central venous lines. Thirty-seven patients were identified over a five-year period. Echocardiograms were performed, not routinely, but in response to specific indications including catheter malfunction, thrombocytopenia, persistent chylothorax, bacterial or fungal sepsis, and superior vena cava syndrome. Fifteen of 37 patients died, 13 of them during the hospitalization in which the thrombus was discovered. Thrombolytic agents and surgery were used to treat selected patients, with mixed results. Two of the 22 survivors have significant disability related to the thrombus or complications arising from it. We conclude that great vein and/or right atrial thrombosis is a common complication of central venous catheterization in small infants and children; moreover, the morbidity and mortality relating to this complication is substantial.

Hemodynamic effects of ketamine in children undergoing cardiac catheterization.

Ketamine is used to supplement sedation during cardiac catheterization. We studied ketamine-induced circulatory changes in 28 acyanotic children (18 of whom had left-to-right shunts), aged 4-161 months (mean, 33 months). Oxygen consumption (VO2) was measured continuously. In the 18 patients with shunts, the pulmonary to systemic flow ratio fell slightly (2.3 +/- 1.1 to 1.8 +/- 0.4, p less than 0.05). In all patients, the ratio of pulmonary (PVR) to systemic vascular resistance (SVR) rose from 0.16 +/- 0.09 to 0.28 +/- 0.21, p less than 0.001. Ketamine increases VO2, heart rate, cardiac output, and pulmonary arterial pressure (PAP). The rise in PAP is more consistent than the rise in PVR; resistance changes were greatest in patients with elevated resting PVR (r = 0.54). Caution should be used in administering ketamine to selected subjects; moreover, ketamine can confuse interpretation of cardiac catheterization data, especially if VO2 is assumed and not measured.

Medical management of three asymptomatic infants with severe valvar aortic stenosis.

We report on the clinical course and serial hemodynamic studies of three patients with severe valvar aortic stenosis diagnosed in the neonatal period. None of the children were symptomatic in the first year of life. In each case, a conservative initial management approach was adopted. Between the time of initial study (mean age, 1.8 months) and the follow-up at 12-27 months of age (mean, 14.3 months), mean left ventricular systolic pressure decreased from 151 to 125 mmHg, the mean peak systolic pressure gradient across the aortic valve decreased from 61 to 33 mmHg, and the mean calculated aortic valve area index increased from 0.24 to 0.60 cm2/m2. One patient was operated on for symptoms that appeared at 14 months of age. The patient followed longest is now 5 years old, is growing well, has a normal electrocardiogram and an echo-predicted left ventricular systolic pressure of 128 mmHg. This experience suggests that not all asymptomatic neonates with severe valvar aortic stenosis require surgical intervention early in life. In some, the aortic valve orifice may increase in size with somatic growth and obviate the need for surgery in infancy or early childhood.