Ozaki Operation

The aortic valve is one of four heart valves. It is located between the left ventricle and the aorta and controls the flow of blood from the heart into the body.

There are two basic types of aortic valve disease:

1. Aortic valve stenosis: The valve has narrowed making the valve opening area smaller and obstructs/prevents blood flow from the heart.
2. Aortic valve regurgitation: The valve is leaking, preventing the valve from closing completely and allowing blood to flow back into the heart.
3. There is often a combination of both aortic valve diseases.

Aortic valve diseases can be successfully treated with the Ozaki method, especially in the case of congenital aortic valve malformations as two or one aortic leaflets instead of three exists or in the case of damaged aortic valve through infection (endocarditis).

Whenever possible, the aortic valve repair is the best option with a long-term prognosis. However, the long-term results depend on several factors, including age, pathology of the diseased aortic valve (existence of calcification, infection), the need of foreign material, which reduces the functionality of repair rapidly as well surgical expertise.

The decision must therefore be made for each patient individually.

In the case of impossibility of aortic valve repair most of the patients undergo aortic valve replacement using either mechanical or biological valve prosthesis.

1. Mechanical aortic valve: it is made of titanium and is especially recommended for younger patients. However, anticoagulation medication should be used livelong to prevent the formation of blood clots.
2. Biological aortic valve: it is usually made from either pig or cow tissue. Biological implants adapt better to the natural blood flow so that a lifelong anticoagulation therapy is not required. However, most biological heart valves must be replaced after 8 - 15 years due to degeneration over time and possibly even faster in young patients or those with chronic kidney disease. So far, biological replacement has been recommended for older patients over 65 years of age. Another recommendation for biological aortic valve prosthesis might be for young women trying to get pregnant, as anticoagulation is associated with risks during pregnancy.

Aortic valve construction, so called Ozaki procedure, goes back to the Japanese cardiac surgeon Prof. Shigeyuki Ozaki (Tokyo). In this procedure all cusps of the diseased aortic valve are removed and replaced using body's own tissue (autologous pericardium), which is treated with glutaraldehyde solution to prevent calcification in future and sewn in using special technique. Thereby, the patient’s natural valve ring is preserved as far as possible and there is no need of postoperative anticoagulation such as with mechanical prosthesis. 

In the case of not suitable pericardium (e.g. due to repeated operations, existence of adhesions) or by use of a minimally invasive procedure, an animal equivalent pericardial tissue can be used as an alternative material.

1. Like a healthy aortic valve, Ozaki valve adapts to current needs during exercise. This is particularly beneficial for children and young, active patients.
2. In patients with a relatively small aortic annulus in relation to their body mass, the risk of inadequate opening (patient-prosthesis mismatch) can be avoided.
3. There is no need of anticoagulation postoperatively.
4. Ozaki valve might be the better alternative in case of valve infection (endocarditis).
5. The larger surface of coaptation with the Ozaki valve in comparison to the artificial valve ensures a better performance of the valve (will be proven by studies).
6. The procedure offers a longer long-term function with a very low risk of calcium deposits even in young patients (will be proven by studies).