Royal North Shore Hospital
North Shore Private Hospital
Suite 3.04 Level 3
North Shore Health Hub
7 Westbourne Street
St Leonards NSW 2065
P: 02 9449 1559
F: 02 9185 3559
The aorta is the main artery coming out of the heart and it distributes the blood and oxygen throughout the body. If the aorta is sufficiently enlarged it is termed an aneurysm and may require surgery. This is because as the aorta grows in size there is a risk of rupture with catastrophic consequences. Aortic aneurysms are often picked up as incidental findings on CT scans or in someone who is being assessed for other cardiac surgery.
Patients generally require surgery if the aorta in the chest has reached 5.5cm in diameter. Additionally, if patients require an aortic valve replacement, then the aorta should be replaced if it has reached 4.5cm in diameter. This is measured on ultrasound (echocardiogram) or CT scans. These are guidelines and not clear-cut rules as it will depend on the individual patient circumstances – for instance, an aorta of 5.5cm is not as much of a problem for a patient who is very tall as opposed to a patient who is shorter – we expect the taller patient to have a larger aorta.
The aorta distributes blood and oxygen throughout the body.
The aim of the operation is to remove the aortic aneurysm and replace it with an artificial aorta usually constructed from a woven fabric called Dacron.
It is major open heart surgery and is performed under general anaesthetic through a vertical incision down the middle of the breastbone (sternum) to expose the heart.
The patient is connected to a heart-lung machine which pumps blood through the body whilst the heart is stopped to operate on it. In many cases the body is cooled down to allow for a decrease in blood flow to the brain whilst the aorta is replaced. This is because it is impossible to replace the arteries to the brain whilst they have a continuous flow of blood.
A Bentall Procedure is an operation for an aortic aneurysm where the first portion of the aorta is replaced. This entails replacing the aortic valve, the aorta itself and reimplanting the coronary arteries. This is reserved for patients with an aortic root aneurysm.
An aortic dissection occurs when the aortic wall splits, which creates two passages for blood to flow – the true lumen and the false lumen. This can be a complication of an aortic aneurysm or of genetic diseases which result in a weaker aorta. This is a major emergency and if it occurs in the first part of the aorta after it emerges from the heart (ascending aorta), requires urgent surgery, usually within the first few hours following diagnosis. Surgery for aortic dissection involves replacing the affected section of the aorta and it carries significant risks that would be explained in detail.
The operation can take between 5 and 12 hours depending on the extent of the aneurysm. Aortic aneurysm surgery is major open heart surgery. The hospital stay and recovery period are usually similar to other open heart surgeries. After experiencing an aortic aneurysm patients will be monitored life-long with CT or MRI scans to ensure that any remaining aorta is not enlarging.
Aortic aneurysm surgery has been performed since the 1960s with excellent results. The risks depend on the extent of the aneurysm with replacement of the ascending aorta being lower risk and replacement of the aortic arch being higher risk. For patients who are otherwise well the risks of surgery on the ascending aorta include: death (3%), stroke (3%), significant wound infection (1%), kidney injury (5%), requirement for a permanent pacemaker (3%) and blood transfusion (50%). The risk is higher for more extensive aortic aneurysms and if the patient has other co-morbidities including advanced age, previous heart disease or stroke, lung disease or having undergone previous cardiac surgery. Dr Bassin will explain these risks to you in person as they pertain to your condition.
You may drive 4 weeks following surgery, according to the national guidelines.