Neurological complications of surgery of the aorta

Introduction. Improvement in cardiac surgery techniques has led to a considerable reduction in mortality following surgery of the aorta, dissection of the aorta and for aortic aneurysms. Although there are satisfactory vascular results following surgical repair, morbi-mortality related to neurological complications, both cerebral and spinal, is still very high. Repair of aortic lesions may lend to damage by two main mechanisms: ischemia secondary to prolonged obstruction of the aorta or to neurological lesions due to total circulatory arrest. Development. After description of the mechanisms leading to cerebral and spinal lesions and the risk factors involved we discuss methods of vascular protection and other means of neuro-protection, both spinal and cerebral. Of the vascular techniques for spinal protection, the most useful ones are short-circuits, or active or passive shunts, and cardiopulmonary by-pass. Amongst the vascular techniques for cerebral protection we describe total circulatory arrest and methods of anterograde and retrograde cerebral perfusion, and when these may be used. As general measures for nervous system protection, we describe the use of hypothermia and drugs such as corticosteroids, free radical blockers, antagonists of the excitatory amino-acids etc. Conclusions. In spite of the number of studies done the extreme sensitivity of the nervous system to ischemia has meant that in few cases have encouraging results been seen. Neurological damage continues to be the main cause of morbi-mortality in patients with dissection or aneurysm of the aorta.