Coarctation of aorta is a localized narrowing of the largest blood vessel of the body supplying oxygenated blood (aorta). It usually occurs in the upper part of the chest and is a birth defect, although similar narrowings of lower part of aorta can occur as an acquired defect. The narrowing leads to higher pressure in the upper extremities than in the lower extremities. The growth of the lower half of the body is also reduced due to the decrease in blood supply.
Coarctation of the aorta can be suspected when the pulses in the lower limb are weaker than that in the upper limbs. Similar changes in blood pressure are also noted with a high blood pressure in the upper limbs and low blood pressure in the lower limbs, depending on the severity of narrowing.
Investigations to confirm coarctation of aorta
The narrowing of aorta can be confirmed by different imaging studies:
- Ultrasound imaging – Echocardiography
- CT scanning – computerized tomographic scanning using X-rays
- MRI – magnetic resonance imaging
- Angiography – injection of iodinated contrast into the aorta and imaging using X-rays
Treatment of coarctation of aorta
Treatment is either by surgery or enlargement of the narrowed region using balloon catheters. Balloon catheters are small tubes with a balloon at the tip, introduced into blood vessels. Recoil of the vessel enlarged by balloon dilatation can be prevented by implanting a metallic scaffold known as stent. The procedure is usually done through a skin puncture in the groin, under local anaesthesia. There is a small risk of vessel rupture if high pressure balloon inflation is used. This risk is more in new cases rather than in recurrences after surgery.
Surgery for coarctation of aorta is done under general anaesthesia and requires opening up of the chest. Recurrence of coarctation of aorta after surgery can occur in a small number of cases. These can be tackled by balloon dilatation.