Congenital aortic stenosis
An aortic stenosis is a malformation of the heart with a narrowing ( stenosis ) of the large main artery ( aorta ), which arises from the left heart and provides the body with oxygenated blood. Congenital aortic stenoses account for about 5 to 7% of all congenital heart defects . They can be divided into three different forms depending on the height of the bottleneck. The is valvular stenosis ( aortic valve ), the most common form of 75 to about 80% of the total. There are also subvalvular aortic stenosis and the rare supravalvular aortic stenosis .
All three forms of aortic stenosis create an obstacle to flow from the left ventricle into the circulatory system . The extent of the stenosis determines how high the pressure load on the left ventricle is, which then enlarges and leads to thickening ( hypertrophy ) of the heart muscles . The complete closure or non- application of the aortic valve is called aortic valve atresia .
The hypertrophic obstructive cardiomyopathy (HOCM), in which the increase in muscle mass in the left ventricle and the septum moved the outflow channel is counted among the acquired aortic stenosis.
Forms of congenital aortic stenosis
| Classification according to ICD-10 | |
|---|---|
| Q23.0 | Congenital aortic stenosis |
| Q24.4 | Congenital subvalvular aortic stenosis |
| Q25.3 | Aortic stenosis (congenital) - Supravalvular aortic stenosis |
| ICD-10 online (WHO version 2019) | |
Aortic stenosis can be caused by three congenital constrictions:
Valvular stenosis
The valvular stenosis is the typical aortic stenosis. It can be caused by a valve ring that is too narrow or by a malformation, adhesions or thickening of the valve leaflets. It is often assumed that instead of three pockets in the aortic valve, only two are created ( bicuspid aortic valve) . Probably more common is a system with a more complex malformation ( unicuspid aortic valve ). The bicuspid aortic valve may also be the most common primary cause of aortic stenosis in adults, which only later become noticeable through secondary inflammation or calcification . In addition, this malformation leads to an increased risk of other diseases of the aorta, such as the aortic aneurysm .
Subvalvular stenosis
The subvalvular stenosis below the aortic valve in the outflow tract of the left ventricle is also called subaortic stenosis . The cause is usually a connective tissue membrane , but it can also occur as a tunnel-shaped narrowing of the outflow path of the left ventricle. Auscultatorily, a loud systolic sound can be heard over the base of the heart (loudest over the second space to the right of the sternum).
Supravalvular stenosis
The supravalvular stenosis is located above the aortic valve in the initial part of the aorta . In this rarely occurring form, there are usually hourglass-shaped constrictions in the initial part of the aorta above the outlet of the coronary vessels. The ascending part of the aorta can, however, also be narrowed over long distances.
Supravalvular aortic stenosis is a key feature of Williams-Beuren syndrome .
Symptoms
Mild aortic stenoses do not cause any disturbances in the physical development, performance or general well-being of children. Moderate and severe stenoses lead to shortness of breath and rapid fatigue during physical exertion. In older children with severe aortic stenosis, sudden exertion can cause severe cardiac arrhythmias and syncope associated with unconsciousness .
Diagnosis
The diagnosis is carried out as with acquired aortic stenosis. The heart ultrasound examination ( echocardiography ) is nowadays the method of first choice as a non-invasive examination method. Magnetic resonance tomography (MRT) is used for high-resolution and functional images of the heart . An electrocardiogram (EKG) is performed to diagnose accompanying cardiac arrhythmias . The heart shape and size are shown in an X-ray . A cardiac catheter examination may also be necessary for specific questions about the decision about the therapeutic approach .
therapy
- A balloon valvuloplasty (the "rupturing" of the narrowed aortic valves with the help of a balloon heart catheter) is only intended for unstable patients as a bridge to the final operation or for inoperable patients as a palliative measure. A newer method, the so-called percutaneous aortic valve replacement, in which a stent with artificial aortic valves (for example made from pig pericardium) is inserted via a balloon catheter, is currently the therapy of choice.
- If this is not possible, the "glued pocket flaps" can be separated in one operation by the surgeon incising the commissures ( commissurotomy ). Both procedures are carried out carefully so as not to provoke valve insufficiency (leakage due to lack of closure). In recent years, other surgical procedures have also been developed that reduce the likelihood of aortic regurgitation ( aortic valve reconstruction ).
- If an aortic valve replacement is necessary, both the use of a homograft (human donor valve ) and the use of an artificial heart valve are possible today .
While a homograft can calcify over time (especially in children) and then has to be replaced, an artificial heart valve lasts for decades. The "disadvantage", however, is that the patients are dependent on a lifelong intake of an anti-clotting drug (e.g. coumarin derivative ) with regular blood tests. There is also a risk of internal bleeding after a fall. Coumarins are teratogenic. Therefore a woman should not become pregnant while taking coumarin.
Ross operation
The Ross operation continues to gain importance in relation to aortic valve replacement. The aortic valve is removed and replaced with the patient's own pulmonary valve. A homograft is implanted in place of the pulmonary valve. This operation is an attractive solution, especially for children and young adults. The aortic valve grows normally with the patient, it is not necessary to take any anti-coagulant medication, and it is possible to exercise.
Replacing the homograft at the pulmonary position is less serious because the pulmonary valve is less stressed than the aortic valve. It can be questionable that a “one valve patient” becomes a “two valve patient”. Therefore, the decision for or against the Ross operation must be made in an intensive exchange between doctor and patient about the patient's wishes for his quality of life and expectations. In the hands of experienced cardiac surgeons who have often performed this operation on patients of all ages, it can now be seen as a very good alternative to "simple" heart valve replacement.
Ross surgery is not performed on people with Marfan syndrome , as the genetic disposition would again lead to aortic valve insufficiency (incapacity to close) or an aneurysm .
Long-term expectations
Life-long cardiac check-ups are necessary. Also on the Endokarditisprophylaxe be taken must.
See also
literature
- S2k guidelines for aortic stenosis of the German Society for Pediatric Cardiology (DGPK). In: AWMF online (as of 2013)
- S2k guideline for supravalvular aortic stenosis of the German Society for Pediatric Cardiology (DGPK). In: AWMF online (as of 2013)
- S2k guidelines for subvalvular aortic stenosis in children and adolescents of the German Society for Pediatric Cardiology (DGPK). In: AWMF online (as of 2013)
Web links
- University Clinic Bonn, Department of Pediatric Cardiology: Aortic Valve Stenosis
