Aortic Disease

What?

 

The aorta is the main blood vessel in the body, running from the heart to the pelvis. It supplies blood to the organs via several smaller branches. When the aorta enters the abdomen from the chest, it is referred to as the abdominal aorta.

Sometimes, due to degenerative changes in the vessel wall, the aorta begins to expand. When this occurs it is called an aneurysm. If the vessel continues to expand, the vessel wall becomes thinner and exposed to more tension. This can lead to the vessel rupturing, a life threatening emergency. Surgery is performed to reduce the risk of the vessel rupturing.

The majority of abdominal aortic aneurysms or AAA are found incidentally, having been picked up on a scan performed for another reason. They generally go unnoticed by the patient and are not painful. If you have new abdominal pain and you know you have a AAA, you should present to the emergency department immediately.

Why?

 

The degenerative process that results in a AAA is caused by a variety of risk factors:

  • Smoking

  • High blood pressure

  • High cholesterol

  • Connective tissue disorders - Rare

Furthermore, having a AAA makes it more likely to have an aneurysms elsewhere, specifically the aorta in the chest and the artery behind the knee - the popliteal artery. In those with known AAA these arteries should also be screened to exclude disease.

AAA tend to run in families. Those with a first degree relative who has had a AAA should undergo a screening ultrasound when they are 50 years of age..

Once they reach 65 years of age, all female smokers and all males also benefit from a one-off abdominal ultrasound to rule out AAA.

What can be done?

 

Aneurysms progressively increase over time. There is currently no medication that can reverse this process. Surgery is the only way to repair the vessel and reduce the risk of rupture. Good evidence however, shows that the risk of an AAA rupturing is relatively small if it is smaller than 5-5.5cm in diameter. Current guidelines and practice dictate that AAAs that are discovered are monitored with surveillance until they reach this size. Once this size threshold is reached, surgery is considered. Adjustments to medications may reduce the risk of expansion and improve overall cardiovascular health.

Currently there are two methods for treating AAA - open repair and endovascular repair.

Endovascular repair is keyhole surgery where a stent graft (synthetic fabric on a metallic scaffold) is inserted through the arteries in the groin. This is placed across the aneurysm and diverts blood flow through the graft. This excludes the aneurysm from the blood flow, reducing the pressure on the aneurysm and therefore reducing the risk of rupture. This procedure is well tolerated and most people are discharged after 2-3 days.

Open Repair is surgery where a synthetic fabric tube is directly stitched in place in the aorta through an incision in the abdominal wall. It is a larger procedure with greater procedural risks and longer recovery time. Long term outcomes are no different to those of endovascular repair.

Not all patients are suitable for endovascular repair as due to unfavourable anatomy of their vessels. Dr Werner-Gibbings undertook a year long fellowship at St Thomas’ Hospital in London. This is a world leading centre at using advanced techniques to allow more patients to have their aneurysms treated in this keyhole manner, even if their anatomy is unsuitable for a standard endovascular repair. During this time he gained significant experience and skills in this type of surgery, enabling him to offer this type of complex aneurysm repair to his patients.

The best course of treatment for you will be discussed at your consultation, taking into account your health circumstances and lifestyle needs.

A detailed description of aortic disease and treatment is available from the ANZ Society of Vascular Surgery via the link below