Balloon dilation catheters

Does mild pulmonary stenosis progress during childhood? A study of its natural course

BACKGROUND

Increase in the gradient in congenital pulmonary valvular stenosis during follow-up is a subject of controversy and could determine the need for treatment in pediatric patients.

HYPOTHESIS

It is postulated that a gradient <50 mmHg shows a stable or decreasing tendency at follow-up for congenital pulmonary valvular stenosis.

METHODS

Thirty-five patients with pulmonary stenosis, isolated and not treated, were followed for 7 years (interquartilic rank 5.7 years) at 1.5-year intervals. Clinical and complementary tests (electrocardiogram, x-ray, Doppler echocardiogram) were undertaken. The gradient was measured by Doppler and by using the clinical formula derived from the New England Study (Ellison). The changes observed from the initial to the final consultation were analyzed by means of the Student's t-test, paired Wilcoxon, and Pearson correlation coefficient.

RESULTS

No significant changes were noted on symptoms or physical examination. Signs of cardiac enlargement diminished on both ECG (R wave in V1, p<0.0001) and x-ray (cardiothoracic ratio, p<0.0007), with a decreasing gradient trend during the follow-up period (p<0.026) as well.

CONCLUSIONS

The gradient trend confirms the stable nature of mild pulmonary stenosis. In our study, we found that patients aged >6 months, whose gradients were below 40 mmHg at the time of diagnosis, remained stable and required no treatment. Furthermore, the follow-up control and clinical management of these patients may then be performed at intervals of 2 years or more.

Acute dissection of the right ventricular outflow tract after balloon dilatation in a patient with previously corrected tetralogy of Fallot

Percutaneous balloon dilatation has been used successfully to dilate various stenoses occurring after repair of congenital heart disease. Acute dissection of a stenotic right ventricular outflow tract occurred after attempted balloon dilatation in a patient with previously corrected tetralogy of Fallot.

Balloon nitinol device: a new possibility for the fixation of balloons in large arteries

We propose a balloon with nitinol needles for the closure of large vessels avoiding the risk of embolisation. To demonstrate the possibility of application, we utilised a prototype consisting of a polyurethane balloon with one nitinol needle which reached the shape for securing the balloon to the vessel wall after changing the temperature of the device. If further research and experimentation in animals are favorable, it will be possible for the interventional cardiologist to occlude large vessels and perhaps intracardiac shunts easily without danger of embolisation.

Applications of intravascular scanning and transesophageal echocardiography in congenital heart disease: tradeoffs and the merging of technologies

This chapter will review the evolving role of intravascular ultrasound imaging and transesophageal echo in the care of children, infants and adults with congenital heart disease. The technologies relevant to congenital heart disease applications differ from those involving coronary disease since the intravascular structures imaged often involve visualization of large vessels and cardiac chambers. On the other hand, the requirements for transesophageal echo in children with congenital heart disease involve intraoperative (surgical) and imaging procedures in the catheterization laboratory which are performed for monitoring interventional catheterization therapy. As such, whereas the intravascular devices needed for pediatric cases involve lower frequency and sometimes larger catheters, the requirements for transesophageal echocardiography require higher frequency and smaller esophagoscopes. Applications of intravascular imaging including sizing of congenital stenoses, dilation of coarctation and valvular stenoses, imaging of intrapulmonary thrombi and monitoring of placement of ASD 'button' devices in the heart will be reviewed. The intraoperative transesophageal uses for monitoring infant surgery include procedures for tetralogy repair, transposition repair and repair of AV septal defects and other complex congenital heart disorders. Both of these 'invasive' methods of echocardiography have an important and evolving role in the management of congenital heart disease in children and infants.