Aortic stenosis | MedUni Vienna

Aortic valve stenosis (balloon valvuloplasty)

Aortic valve stenosis in children is congenital and not caused by degeneration as in adults.

Treatment of aortic valve stenosis is either surgical or catheter-interventional. The surgeon can make targeted incisions in the narrowed valve sections (commissures), but a heart-lung machine is required for this operation.

Balloon dilatation (valvuloplasty) has established itself as an alternative procedure, particularly for critically ill newborns.

Indication

When an aortic valve needs to be treated depends on its severity. The following threshold values and indications correspond to international guidelines:

Critical aortic stenosis of the newborn
Severe aortic stenosis with heart failure regardless of the pressure gradient
Doppler gradient in ultrasound ≥ 64 mmHg (instantaneous gradient)
Doppler gradient in ultrasound > 40 mmHg (mean gradient)
Any symptomatic aortic stenosis (syncope, angina pectoris, arrhythmia)
Moderate aortic stenosis, if there are also ECG changes

Simultaneous leaks that are more than second degree no longer permit balloon valvuloplasty.

Technics

Balloon dilatation is safe to perform with today's technology and can delay surgical intervention until adulthood.

The inguinal artery (femoral artery) is usually used as the access route, but transvenous dilatation can also be performed, although it is technically somewhat more difficult.

A guide wire is used to probe the aortic valve against the blood flow in the aorta and this is placed in the left ventricle. The actual balloon catheter can now be positioned in the valve via this guide wire. The diameter of the balloon in relation to the diameter of the aortic valve should not exceed 0.8-0.9.

For the duration of the balloon filling, the heart is simultaneously stimulated to a high heart rate (usually 250-280 beats/min) using a pacemaker (rapid ventricular pacing). This ensures that the balloon catheter does not slip out of position. As soon as the balloon is deflated again, the pacemaker stimulation is stopped and the heart beats normally again.

Course

It has been shown that pacemaker stimulation during aortic valve dilation results in significantly fewer leaks in the aortic valve. Nevertheless, an increase in aortic valve insufficiency up to adulthood must be expected with both balloon dilatation and surgery.