Which artificial heart valves are available?
An artificial heart valve basically consists of two elements. On the one hand, there is a framework which is surrounded by polyester (plastic). This framework forms the transition between the valve and the human heart.
Inside the scaffold is a metal valve. There are different types of valves. A distinction must be made between three different models.
The different types of valves each have advantages and disadvantages due to their sizes and different mechanical properties and are therefore suitable for different patient groups. All three types of valves trigger the typical prosthesis click, where you hear the valve leaflet hitting the valve ring.
- There is the artificial heart valve, which consists of a tilting disc. The most prominent representative of this valve type is the Björk-Shiley prosthesis.
- There are also double-wing flaps such as the St. Jude Medical.
- The third type of flap is called ball flap. The best known of these is the Rigid Edwards ball valve.
OP – Inserting the heart valve
There are now various ways of inserting an artificial heart valve. One option is still major open-heart surgery, in which the chest and heart are opened to remove the affected valve and insert the new artificial heart valve. During the major open surgery, the patient is under general anesthesia.
The chest is opened by cutting through the sternum to access the heart behind it. Most operations are performed on a non beating heart. Instead, the so-called heart-lung machine takes over the function.
As soon as the new artificial valve is inserted, the heart is made to beat again. Another method is the so-called minimally invasive procedure, in which the artificial valve is inserted like a stent via the inguinal arteries into the vascular system and then advanced to the heart. However, this is only possible when replacing the aortic valve, as this is located at the exit of the heart, which is reached via the arterial vascular system.
The non-invasive method in which the valve is inserted via the inguinal artery is called TAVI. TAVI stands for transcatheter aortic valve implantation. The new artificial aortic valve is inserted via a cardiac catheter.
The catheter is advanced over the vascular system up to its point of insertion, where it unfolds the artificial heart valve. This is done while the heart is beating. The new valve presses the old, defective valve against the wall.The operation for artificial heart valves is performed under general anesthesia.
This results in a fundamental health risk, independent of the surgical procedure, which also increases with age and an increasing number of previous illnesses (especially in the cardiovascular system). In addition, the thorax must be opened during the operation to ensure access to the heart. In order to insert the artificial heart valve, the heart has to stop for a certain period of time.
For this purpose, the affected person is connected to a heart-lung machine, which performs the pumping function of the heart. The heart can then be immobilized with medication. Since the heart-lung machine is a very common procedure, the risks here are rather small, even though it is a very severe intervention in the body’s own functions.
Sawing or cutting open the chest is also a great strain on the body. There is also the risk of bleeding or infection in the area of the wound and around the heart. Infections can also occur later, when bacteria attach themselves to the artificial heart valve.
The time spent in the hospital initially consists of the admission day, which is usually one day from the operation. The operation is followed by two to three days in the intensive care unit to monitor heart function. This is followed by a stay in a normal cardiological ward of about two weeks.
In most cases, the hospital stay is immediately followed by inpatient rehabilitation, which in turn lasts another three to four weeks. All in all, a hospital stay of six to seven weeks must be assumed. The rehabilitation after an artificial heart valve usually takes place directly after the stay in hospital.
There are various focal points that are dealt with in the course of rehabilitation. Physical therapy, gymnastics and fitness training are used to improve physical performance. There is an educational program on nutrition and medication. Psychological problems such as anxiety, depression and prolonged pain are also treated.
