AORTIC STENOSIS IN CHILDREN
- If the blood flow between left ventricle (main chamber of the heart) and aorta (main blood vessel of the heart) is blocked, it is known as Aortic Stenosis.
- This is a congenital heart defect (CHD).
- Aortic stenosis can occur in newborn, infants, children and adolescents and even in adults.
- Aorta is having a valve at its origin that is known as aortic valve.
- Blockage can occur at the level of valve, below the level of valve or above the level of valve, it is known as valvular, subvalvular or supravalvular aortic stenosis respectively.
- Aortic valves regulate blood flow to the body parts. When aortic valve opens, it allows blood to go forward then it closed down so that blood will not come back to left ventricle.
- However, if there is a problem with the aortic valve or above or below this valve, it cannot open entirely and that restricts the passage of blood into aorta. The heart has to work extra hard to ensure that the entire volume of blood flow through the faulty valve or left ventricle outflow tract.
- Sometimes babies are born with deformed aortic valve in the form of bicuspid aortic valve (bicuspid aortic valve) that is prone for obstruction as compared to normal trileaflet aortic valve.
- Aortic stenosis is more common among boys than in girls.
Cause of Aortic stenosis in children:
- If blockage is in the aortic valve itself, it is mainly in the form of deformed aortic valve (bicuspid aortic valve stenosis), it is known as Valvular aortic stenosis. Normally aortic valve has 3 leaflets; when it is having 2 leaflets then it is known as bicuspid aortic valve; when having one leaflet then known as unicuspid aortic valve.
- When there ia an obstruction beneath the aortic valve by muscular/fibrinous tissues, it is known as Subaortic stenosis.
Supravalvar aortic stenosis:
- It commonly occurs with a syndrome known as ‘Williams syndrome’.Blockage in aorta can be in the form of hourglass shape or funnel shaped type.
Symptoms of Aortic stenosis:
- Presentation of patient with any type of aortic stenosis depends on severity of obstruction at any level and age of presentation.
- In mild aortic stenosis, children are generally asymptomatic and can be detected only on routine examination by a local doctor in the form of abnormal heart sound (aortic stenosis murmur) on examination.
- As severity of obstruction increases, child can presents with easy fatigue (get tired early as compared to his/her peer groups), chest pain, loss of consciousness (syncope) and in later stages with shortness of breath (dyspnea due to heart failure).
- Neonates who born with severest form of aortic stenosis (known as Critical Aortic Stenosis), generally are in shock like state with heart failure.
Aortic Stenosis Diagnosis in children:
- Pre-natal testing in the form of fetal echocardiogram can reveal aortic stenosis during pregnancy state (even before delivery of the child). It helps in planning of delivery of the child for timely initiation of treatment as soon as newborn is delivered.
- After birth, aortic stenosis can be diagnosed by doing Pediatric Echocardiogram from the chest of the child.
- ECG, Chest X ray and sometimes CT/MRI angiogram also help in making and confirming the diagnosis.
- When we are in doubt by above diagnostic modalities, then we need to perform cardiac catheterization in cath lab.
Treatment of Aortic Stenosis in children:
- If aortic stenosis is mild to moderate in intensity then we need to do follow-up of the child at regular intervals.
- However, in severe aortic stenosis, treatment needs to be done. Treatment depends upon level of obstruction.
- In valvular aortic stenosis, treatment of choice is by doing ballooning of aortic valve (Balloon aortic valvuloplasty, BAV) in any age group. Now a day, surgical opening of aortic valve is very rarely recommended (Surgical Aortic Valvotomy).
Balloon Aortic Valvuloplasty:
- This is not an open-heart surgery. It is done in cardiac cath lab under fluoroscopic guidance by using vessels in thigh. We cross the valve with wire and catheters and we inflate a balloon across the stenosed aortic valve.
- Neonates with critical aortic valve stenosis will require urgent balloon dilatation of aortic valve soon after birth.
- Cost for aortic valve balloon dilatation is very reasonable now a day.
Aortic valve balloon dilatation risks:
- Balloon valvuloplasty of aortic valve stenosis reduces blockage with very low risk of morbidity and mortality in pediatric age group.
- Aortic Stenosis Surgery by open heart surgery method:In subvalvular and supravalvular aortic stenosis, treatment is only by doing heart surgery after opening the chest.
- Aortic valve replacement (AVR): An artificial valve or a donor valve is surgically attached at aortic valve location when valve is not amenable for ballooning. It is generally done in adolescent or adult patients.
- ROSS procedure
- Aortic homograft
Aortic Stenosis treatment Result
- Now a day, results of balloon aortic valvuloplasty (BAV) are excellent.
- However, in long term, aortic valve stenosis can recur in long term.
- If it recurs, then balloon dilatation of aortic valve may be repeated for opening the aortic valve.
- If child underwent surgery for subvalvular or supravalvular aortic stenosis then results of surgery is also good in these cases as well.
- Mortality after open heart surgery is extremely rare even after replacement of aortic valve (aortic valve replacement; AVR).
- When child requires aortic valve replacement early in life then it may be small in size for the outgrow weight and size of the child so it may also require re-implantation of aortic valve in future.
- The life expectency of artificial aortic valve is extremely good.
- It is important to understand that we cannot make normal valve by use of any treatment methods, all the treatments for aortic stenosis are palliative, not curative.
- Children affected with aortic stenosis will require long-term follow-up with a pediatric cardiologist.
Supravalvar aortic stenosis
Valvular Aortic Stenosis
Subaortic membrane with stenosis