Aortic dissection occurs when a split or tear suddenly develops in the wall of the aorta, creating a second channel of blood flow within the vessel (Figure). The second channel or ‘false lumen’ can lead to complications including
- Severe pain or high blood pressure
- Dilatation (aneurysmal degeneration)
- Rupture or the false lumen (usually preceded by acute or chronic dilatation)
- Blockage of blood flow to vital organs resulting in kidney failure, lack of blood supply to the bowel, lack of blood supply to the limbs or to the spinal cord (paraplegia)
Cause: Although the development of aortic dissection may be associated with a genetically based tissue abnormality, in most cases aortic dissections occur when there is disease of the aorta as a result of atherosclerosis, often combined with high blood pressure.
Treatment: Treatment will depend on the location and the extent of the dissection, and usually on the presence or absence of complications. Dissections that arise close to the heart will usually require open heart surgery to correct, whereas dissections which do not involve the (ascending) first part of the aorta may be suitable for treatment with a Stent Graft (See interventions). All patients will need careful and intensive control of blood pressure acutely and in the long term.
A reconstructed CT Scan image of aortic dissection, illustrating the split along the length of the blood vessel, creating two channels (lumens) when there should be one.