Aortic stent – implanted using a minimally invasive procedure to stabilize the aorta

The aorta is the body’s main artery. It carries oxygen-rich blood from the heart to the organs. A dangerous condition is an aortic aneurysm, a pathological bulge or enlargement of the aorta.

Under certain circumstances, an aortic aneurysm can rupture, which often leads to rapid internal bleeding. The risk of rupture increases as the aneurysm’s diameter grows.

To prevent this, once the aneurysm reaches a certain diameter, it should be isolated from the bloodstream. This means that blood no longer enters the bulge.

This can be done through open or endovascular surgery.

• In open surgery, the abdominal cavity is accessed through a large, longitudinal incision in the abdomen. The aneurysm is then removed and a plastic tube is sutured directly into the site.
• Alternatively, the surgeon can advance an aortic stent graft into the aortic aneurysm via the femoral arteries (endovascular therapy). X-rays allow the graft to be visualized through the skin without having to expose the abdominal aorta.

An aortic stent graft is a small metal mesh tube (stent) covered with plastic. The difference between an aortic stent and an aortic stent graft is the plastic coating. An aortic stent refers only to the metal mesh without the plastic coating.

The aorta is the largest artery in the human body. Over time, many people develop hardening of the arteries (atherosclerosis). This also applies to the aorta. In smaller arteries, the damage usually leads to a narrowing of the vessel. In the large aorta, the weakening of the vessel wall manifests primarily as a dilation.

Arteriosclerosis is the main cause of an aortic aneurysm. A much rarer cause is a hereditary (congenital) weakness of the connective tissue known as Marfan syndrome.

The risk of arterial calcification increases gradually with age. Your blood vessel walls change over the years. They lose elasticity and become increasingly less able to withstand the high pressure exerted on them. High blood pressure is one of the risk factors that place a strain on the blood vessels.

Bacterial infections are also considered a cause associated with the development of aneurysms. Infections lead to inflammatory processes, including those affecting the blood vessel walls. Over time, this develops into a vascular bulge known as a mycotic aneurysm.

Here, too, treatment with an aortic stent graft is necessary if the bulge becomes too large.

An aortic aneurysm usually causes no problems. In particular, pain or circulatory disturbances occur only rarely. Often, the patient is completely unaware that they have an aortic aneurysm and is surprised when an ultrasound examination reveals the dilation of the abdominal aorta.

Normally, the abdominal aorta has a diameter of about 2 centimeters. If the diameter reaches 5 centimeters or more, the aneurysm should be treated surgically.

There is no one-size-fits-all answer to this question. Both procedures have their advantages, disadvantages, and limitations in terms of applicability.

Advantages and Potential Risks of the Aortic Stent Graft

The clear advantages of an aortic stent graft are

• less physical strain on the body and
• smaller incisions.

Often, an incision is no longer necessary at all—specifically when the femoral artery is accessed through the skin via a puncture. For this reason, the hospital stay is often significantly shorter, and patients can return to their normal daily routine without any problems after just a few days.

A disadvantage of the aortic stent graft is that it involves radiation exposure during the surgery. This is particularly important to consider in younger patients.

In addition, regular follow-up examinations must be performed after the surgery. These often involve computed tomography (CT) scans and, later on, ultrasound examinations.

The intervals between checkups are relatively short at first (3–6 months) and eventually become annual if the results are normal. The reason for these regular checkups is that the prosthesis is not sutured in place but is inserted into the vessel from the inside. Over time, however, the vessel may dilate again—this is a characteristic of the underlying condition, an aneurysm. If this happens, the prosthesis can shift and develop a leak.

A displaced or leaking aortic stent graft no longer provides protection: If the aneurysm ruptures while the aortic stent graft is leaking, the risk of death from hemorrhage is once again very high.

Advantages and Potential Risks of Open Surgery

After open surgery, follow-up examinations are rarely, if ever, necessary. As a result, radiation exposure is negligible both during and after the procedure. In addition, the likelihood of requiring follow-up procedures is significantly lower. 

Once the aneurysm exceeds a certain size, a CT scan is recommended. This allows physicians to accurately visualize the aneurysm and assess the surrounding vascular regions.

A careful measurement is then performed to determine whether the use of an aortic stent graft is feasible in principle. Ideally, the patient is then given a detailed explanation of the advantages and disadvantages of both procedures, and a medical recommendation is made.

The patient may also choose to forgo surgery entirely; however, in that case, they will face a certain risk of rupture.

The implantation of an aortic stent is performed using a minimally invasive technique as part of an endovascular procedure. In most cases, access is gained through the femoral arteries. After administering local or general anesthesia, the doctors puncture the artery and insert a thin catheter, which is advanced under X-ray guidance to the affected area of the aorta. The folded stent prosthesis is delivered into the aorta via this catheter.

Once the correct position is reached, the specialists unfold the aortic stent and anchor it to the inner wall of the aorta. This isolates the aneurysm or dissection from the blood flow, so that no further stress is placed on the weakened vessel wall. After verifying blood flow, the catheter is removed and the incision in the groin is closed. Since only small incisions are required, the recovery time is usually short, and most patients can be discharged after just a few days.

The experts for this type of procedure are

• specialists in vascular surgery,
• specialists in cardiac surgery (from the Greek: kardia = heart), and
• specialists in thoracic surgery (thorax = chest).

There is often close collaboration between these specialties.