What is an aortic prosthesis?
An aortic prosthesis is a vascular prosthesis that is inserted into the aorta. It is an implant that is inserted permanently into the body for therapeutic reasons. It replaces sections of vessels that have been damaged, for example, by aortic dissection, aneurysm or trauma. This repairs the defect and prevents the damage from worsening, e.g. a life-threatening rupture of an aortic aneurysm.
Indications for an aortic prosthesis
The most common indication for an aortic prosthesis is an aortic aneurysm. In the case of an aneurysm, the wall of the vessel is dilated. If the diameter of the aneurysm becomes too large, an aortic prosthesis must be inserted.
This is because the larger the aneurysm becomes, the greater the pressure on the vessel wall and thus the risk of a life-threatening aortic rupture increases. The affected area of the aorta is then replaced by the prosthesis, which can be inserted using various methods. Aortic dissection is a special form of aneurysm which is also treated with an aortic prosthesis.
A tear in the inner vessel wall causes the vessel wall layers to split. Here too, there is a risk of aortic rupture. Another indication is trauma, such as an accident. In this case, external forces can cause injuries or even a complete rupture of the aorta. An operation should then be performed as soon as possible, during which the prosthesis is inserted to keep blood loss to a minimum.
How is an aortic prosthesis implanted?
There are basically two options for using an aortic prosthesis: vascular surgery or catheter surgery. Surgery is mainly used to treat aneurysms in the thoracic cavity, especially in the ascending aorta and the aortic arch, but also in the abdominal cavity. The affected part of the aorta is replaced by a tissue tube.
During the procedure, a heart–lung machine is used to enrich the blood with oxygen and pump it back into circulation while the aorta is disrupted. In addition, the blood is cooled down to slow down the circulation and protect the brain. Interventions via catheter are much gentler than surgery.
They are mainly suitable for abdominal aneurysms. A vessel in the groin is punctured and the stent is advanced to the affected area via catheter. There it unfolds and thus surrounds the aorta from inside and the aneurysm is removed from the bloodstream.
What material is an aortic prosthesis made of?
Aortic prostheses are artificial tissue tubes. They are usually made of plastics such as polyethylene terephthalate (PET). PET is generally used for large vessels, such as the aorta.
PET prostheses are tubular and have a folded surface, making them more flexible and better able to mimic the properties of real vessels. Some time after implantation, the inner layer of the prosthesis is naturally covered by platelets. This creates a layer similar to the inner layer of natural vessels.