Repair of Aortic Dissection (Tear in the wall of the Aorta)

The aorta is the largest artery in the body. It arises from the left ventricle (one of the four chambers of the heart) and supplies oxygenated blood to the entire body. The aorta is divided into the ascending aorta (first part that arises from the heart), aortic arch (middle curved region) and the descending aorta (last section that travels down the chest). The aortic wall is made up of three layers. Weakness in the aortic wall can cause a tear in the inner layer, allowing blood to leak into the middle layer, and separating or dissecting the two layers. This is called aortic dissection. The dissection can sometimes cause a rupture in the outer wall, which can be fatal. An aortic dissection is a rare condition that is most frequently observed in men aged 60 to 70 years of age.

Aortic dissections are divided into two types, depending upon the part of the aorta affected:

• Type A: The tear occurs in the ascending aorta. It is more common and dangerous.
• Type B: The tear occurs in the descending aorta.

Diagnosis

As the symptoms of aortic dissection are similar to that of other heart problems, your doctor diagnoses aortic dissection by the following specific signs and symptoms:

• Difference in pulse between the left and right arms
• Fainting
• Sudden weakness, difficulty in speaking, loss of vision or paralysis on one side of your body
• Sudden stabbing chest pain
• A widened aorta on an X-ray image of the chest

A few sensitive imaging tests may also be performed that include computerized tomography (CT) scan, magnetic resonance angiogram (MRA) and transesophageal echocardiogram (TEE).

Treatment

An aortic dissection is a life-threatening condition that requires immediate treatment in the form of medical therapy or surgery depending upon the region of the aorta affected. Type A dissection would require emergency surgery, while type B dissection is usually monitored and managed with medication until it gets severe.

Open Surgery

The repair of aortic dissection is performed under general anaesthesia. In an open surgery, your surgeon makes an incision in the centre of the chest and separates the breastbone to access the chest cavity. Your heart would be connected to a heart-lung bypass machine (that takes over your heart’s pumping action and moves blood away from your heart) to keep your heart still while performing the surgery. Your surgeon then examines the aorta and sutures the layers of the dissected aorta and repairs the tear. The aorta is then reinforced with a graft (a tube made up of a synthetic material). The graft is then sutured in its place so that the blood flows through the graft. If the valve controlling the unidirectional flow of blood from the heart to the aorta is damaged, it is repaired or replaced. The heart is disconnected from the heart-lung machine and restarted. The breast bone is joined and the chest incision is closed.

Endovascular Aortic Repair

Endovascular aortic repair is a minimally invasive procedure that requires only a small surgical incision in the groin. With specially designed instruments, your surgeon repairs the aortic wall and introduces a stent graft (a polyester tube within a metal cylinder). Under the guidance of X-rays, your surgeon inserts a catheter (thin long tube) with the stent attached at its end into the femoral artery in the groin and advances it to the weakened portion of the aorta. The stent is expanded at the region of the defect, so that the blood flows through the stent graft avoiding the dissection. This repairs the leakage and avoids pressure on the aorta.

Following an open surgery, you are required to stay in the hospital for a week or two, or 2 to 3 days for an endovascular procedure. Complete recovery takes about 6-8 weeks.