What does surgery involve?
Sometimes arch and descending aneurysms can be repaired by open surgery. Depending on the location of the aneurysm, the incision is either through the breastbone (median sternotomy) or into the left chest, between the ribs (left posterolateral thoracotomy).
Cardiopulmonary bypass (heart-lung bypass) is used to divert blood around the aneurysm, and then clamps are placed above and below the aneurysm. Then the aneurysm is cut out and replaced with a synthetic tube of the appropriate size. This tube is sewn to the ‘stumps’ of normal aorta above and below the aneurysm.
There are procedural risks that are specific to surgery, and these centre around the fact that the blood flow to major organs (the brain, spinal cord, kidneys, liver, bowels etc) may have to be interrupted as the aneurysm is excised and replaced. Therefore your surgeon will counsel you about the risks of death, stroke, paraplegia, organ dysfunction and so on.
It is also true that the operation is long and there is a significant risk of major blood loss, necessitating transfusion of blood or clotting products. These risks have to be balanced against the risk of death, stroke, paraplegia and so on if the aneurysm were to dissect or rupture without treatment. Your surgeon will help to advise you on the balance of risk.