Ross procedure in congenital patients: results and left ventricular function.

METHODS: From April 1990 to August 1995, 121 patients (median age 42 years) underwent aortic valve replacement with allografts (69 patients) or autografts (52 patients). In this latter group, 24 Ross procedures have been performed in congenital patients since November 1991 (median age 10 years, range five months to 27 years): aortic incompetence (n = 17), isolated aortic stenosis (n = 5), small stenotic prosthesis (n = 2). Transthoracic echocardiography was obtained preoperatively in all patients and serially after surgery with the aim of measuring aortic and pulmonary annuli and evaluate gradients and incompetence and to study the left ventricular function. Intraoperative transoesophageal echocardiography was routinely used. Complete root replacement was performed in all patients. RESULTS: One patient died in the early postoperative period (4%). There was no late death. All survivors remained in NYHA class I and were free of complications and medications. No gradient nor any significant aortic incompetence could be demonstrated. In 17 patients with predominant aortic incompetence before surgery, the left ventricular function was followed prospectively, end-diastolic left ventricular dimensions diminished drastically from 2 +/- 3.4 S.D. above normal to -0.63 +/- 2.4 S.D. at one week postoperatively (day 10) to reach a normal value one to three months after surgery. Left ventricular mass remained abnormal at day 10 (from 4.7 +/- 3.3 S.D. to 5.3 +/- 3.8 S.D.) and diminished more progressively to reach a normal value (0.14 +/- 1.4 S.D.) at three months. This resulted in a significant decrease of end-systolic wall stress (-3.6 +/- 2.1 S.D.) and in a hyperdynamic function in the immediate postoperative days except in two patients. These two patients were characterized preoperatively by more severely dilated left ventricle (end diastolic dimension 5.3 +/- 0.03 versus 1.6 +/- 3 S.D.) with decreased left ventricular wall thickness (1.19 +/- 0.7 versus 3.44 +/- 1.9 S.D.), decreased ratio between end diastolic wall thickness and end diastolic dimension (0.14 +/- 0.06 versus 0.2 +/- 0.06) and a decreased velocity of shortening. Unlike the other 15 patients, the left ventricular function did not recover completely at mid term follow-up in those two patients. CONCLUSION: The Ross operation is a safe procedure and allows us to suppress completely the abnormal loading conditions of the left ventricle, resulting in a complete recovery of left ventricular function in most patients.

Early balloon dilatation of the pulmonary valve in infants with tetralogy of Fallot. Risks and benefits.

BACKGROUND: Balloon dilatation, an established treatment for pulmonary valve stenosis, remains a controversial procedure in tetralogy of Fallot. METHODS AND RESULTS: Balloon dilatation of the pulmonary valve was performed in 19 infants with tetralogy of Fallot. Its effects on the severity of cyanosis, the growth of the pulmonary valve and pulmonary arteries, and the need for transannular patching were evaluated. Clinical, echographic, angiographic, hemodynamic, and operative data were analyzed. The procedure was safe in all, without significant complications. After balloon dilatation, systemic oxygen saturation increased from a mean value of 79% to 90%. This increase proved to be short-lasting in 4 patients, who required surgery before the age of 6 months. Balloon dilatation increased pulmonary annulus size in each case, from a mean value of 4.9 to 6.9 mm (P < .001). This gain in size remained stable over time, with a mean Z score of -4.8 SD before dilatation, -3.1 SD immediately after the procedure, and -2.7 SD at preoperative catheterization (P < .001). Pulmonary artery dimensions remained unchanged immediately after balloon dilatation but increased at follow-up from a Z score mean value of -2.5 to -0.06 SD and from -2.2 to 0.04 SD for right and left pulmonary arteries, respectively (P < .001). At the time of corrective surgery, the pulmonary annulus was considered large enough to avoid a transannular patch in 69% of the infants. This represented a 30% to 40% reduction in the need for a transannular patch compared with the incidence of transannular patch expected before balloon dilatation. CONCLUSIONS: Pulmonary valve dilatation in infants with tetralogy of Fallot is a relatively safe procedure and appears to produce adequate palliation in most patients. It allowed the growth of the pulmonary annulus and of the pulmonary arteries, resulting in a mean gain of 2 SD for those structures.

Pulse oximetry versus measured arterial oxygen saturation: a comparison of the Nellcor N100 and the Biox III.

Pulse oximetry is noninvasive, fast, and simple, making it a very popular way of assessing oxygenation in pediatric patients. However, there are few studies that establish the accuracy of this technology over a wide range of oxygen saturations in children. This study, done in 47 children aged from 1 day to 16 years with congenital heart disease and undergoing cardiac catheterization, compared the direct measurement of arterial oxygen saturation to values from pulse oximetry. Oxygen saturation was measured by an IL-282 Co-oximeter, which also measured carboxyhemoglobin and methemoglobin, and was compared to values obtained from both a Biox III and Nellcor N100. Both pusle oximeters gave values that closely correlated with the actual saturation (r = 0.91 and 0.93, respectively) with standard errors of the estimate of 4.1 and 3.2%, respectively. For both devices, the error increased with decreasing saturations, being progressively larger below a saturation of 80%. The difference between the actual saturation and that measured by pulse oximetry bore no relationship to the presence of carboxyhemoglobin, methemoglobin, fetal hemoglobin, bilirubin, cardiac index, or age of the patient. In conclusion, pulse oximetry, while a very useful technology in pediatrics, must be interpreted with some caution in children with severe cyanosis.