Objective: To evaluate immediate and midterm results with percutaneous aortic valvoplasty. Material and Methods: We reviewed the records of 141 patients undergoing percutaneous aortic valvopasty over a period of 13 years. Results: The patients were aged from 2 months to 40 years, with a mean of 10.9 ± 9.9 years. Of the total, 90 (63%) were male. The initial systolic peak-to-peak gradient decreased from 163 ± 52 mmHg to 32 ± 18 mmHg (p > 0.01) after valvoplasty in all 141 patients, while the proportional reduction ranged from 0 to 100%, with a mean of 72 ± 27%. The index of the size of the balloon to the diameter of the valvar orifice was 0.88 ± 0.19 in 128 patients. The follow-up ranged from 6 to 168 months, with a mean 51 ± 48 months in 70 patients. A significant difference was found in those failing after dilation when the initial evaluation was compared to the final evaluation of patients with follow-up. In those failing, the number of patients rose from 12 (17%) to 21 (30%) (p > 0.01). In contrast, in those in whom we achieved success, there was not such a great difference between the initial and final evaluation: 58 (83%) versus 49 (70%) (p > 0.1). The actuarial freedom curve of patients not needing new percutaneous aortic valvoplasty or surgery, by 182 months, was at 87% and 82% respectively. Conclusion: We have reviewed the largest series of patients in Latin-America reported thus far after undergoing percutaneous aortic valvoplasty, concentrating on mid term follow-up and limitations. New prospective and multicentric studies are needed from our region.

We evaluated the clinical significance of the configuration of right ventricular pressure curves after balloon valvoplasty in 35 patients with pulmonary valvar stenosis. Right ventricular pressures were measured with a fluidfilled catheter. We divided the subjects into two groups according to the pressure curves seen after balloon valvoplasty. In eight patients, two peaks were found in the curves, with the higher peak occurring at late systole. The remaining 27 patients had a single peak observed during early to mid systole. In all patients in the group with a single peak, the ratio of ventricular pressures decreased by more than half, and no residual narrowing was seen in right ventricular outflow tract, the diameter after valvoplasty increasing by more than half over the diameter before the procedure. In contrast, in five of eight patients in the group with double peaks in the pressure curves, the ratio between ventricular pressures remained higher than 0.5, and the diameter of the right ventricular infundibulum was reduced to less than half the diameter prior to balloon valvoplasty. In three of these patients with double peaked pressure contours, to whom propranolol was administered intravenously, the pressure configuration changed to one with a single peak and the ventricular pressure ratio fell to below 0.5. The degree of obstruction of the right ventricular infundibulum also decreased. These data suggest that a high right ventricular pressure and two peaks in the pressure curve with the higher peak at late systole after balloon valvoplasty indicate, first, the presence of a significant narrowing in the right ventricular outflow tract and, second, effective balloon valvoplasty.

Balloon dilation of the pulmonary valve was performed in 54 patients with tetralogy of Fallot with severe cyanosis, high haematocrit and severe valvar pulmonary stenosis. Clinical, echocardiographic, angiographic, and haemodynamic data were analyzed before and after the procedure. After balloon dilation, the systemic oxygen saturation increased from a mean value of 66% to 85<%. The mean value of the haematocrit before dilation was 55 + 13, and decreased to 47 after dilation (p < 0.002) in 2 months follow-up. Balloon dilation increased the size of the pulmonary valvar orifice from a mean value of 9 + 5mm to 11.5 + 2mm (p < 0.005). The mean Z score of the pulmonary valves, which was -3 + 1.3 before dilation, increased to -1.1 + 1.1 immediately after the procedure (p < 0.05).

The size of the right and left pulmonary arteries increased after dilation from 9mm to 10 mm, and from 8.7 + 2.4mm to 9.8 + 2.3mm, respectively (p <0.05). The comparable mean Z scores increased from -2.8 + 1.9 SD to -1.8 + 1.4 SD, and from -2.4 + 1.9 SD to -1.5 + 1.6 SD for the right and left branches, respectively (p < 0.05).

In patients with stenosis at the bifurcation of the pulmonary trunk and hypoplasia of the left artery, successful dilation of the pulmonary valve lead to an increase of flow and improvement in size of the hypoplas-tic segment.

In conclusion, initial balloon dilation of the pulmonary valve in tetralogy of Fallot resulted in increase of the Z score for the pulmonary valve and improved antegrade pulmonary blood flow, inducing growth of the pulmonary arteries and ameliorating the anatomic and physiologic preoperative condition.

CRITICAL STENOSIS OF BOTH PULMONARY AND AORTIC valves is an exceedingly rare congenital combination.1−3 In recent years, balloon dilation of these valves in isolation has been reported with good results in children, infants and even newborns.4−6 We now report successful concurrent percutaneous balloon dilation for severe congenital pulmonary and aortic valvar stenosis in an 18-month-old child.

Balloon pulmonary valvoplasty was performed in a patient with congenitally corrected transposition, aged 28 years, who had already undergone surgical closure of a ventricular septal defect and implantation of a conduit between the pulmonary arteries and the right-sided morphologically left ventricle. The patient developed stenosis of the conduit 22 years after the procedure as confirmed by cardiac catheterization and angiocardiography, which also showed stenosis of the native pulmonary valve. A balloon valvoplasty of the native valve was carried out with improvement of the gradient from the ventricle to the pulmonary arteries. The patient developed complete heart block immediately after the procedure, which reverted to first degree block in one week and to the previous cardiac rhythm within 21 days.

Two neonates with severe pulmonary stenosis deteriorated immediately after successful balloon valvoplasty as a result of increased infundibular obstruction. They were treated with β-adrenoceptor blockers and intravascular expansion with limited success. Phentolamine was then given, resulting in dramatic improvement. The children could be weaned from the ventilator within hours of starting this new therapeutic modality.

The diameter of the pulmonary outflow tract was measured from the right ventricular cineangiogram at different phases of the cardiac cycle prior to balloon valvoplasty in 54 patients with congenital pulmonary valvar stenosis. Measured at the level of the hinge point of the valvar leaflets, the pulmonary outflow tract was found to be largest at end-diastole and smallest at end-systole. The mean increase in diameter from systole to diastole was 25.3% (range 6–53%) for 47 patients with typical valvar stenosis, and 24.3% (range 14–41%) for seven patients with dysplastic valvar leaflets (p>0.5). Dilatation using balloons less than 1.2 times the size of the maximal end-diastolic diameter produced a mean reduction in the pressure gradient from right ventricle to pulmonary trunk of 71.1%, compared to 76.2% with bigger balloons (p>0.3). Two patients with an initial ratio between balloon and outflow tract of 0.9 required a second dilatation. The timing of measurement of the diameter of the pulmonary outflow tract should be standardized. Oversized balloons probably are not necessary for pulmonary valvoplasty.