Prevention of spinal cord ischaemia during descending thoracic and thoracoabdominal aortic surgery

Surgery of the descending and thoracoabdominal aorta has been associated wi th post-operative paraparesis or paraplegia. Different strategies, which ca n be operative or non-operative, have been developed to minimise the incide nce of neurological complications after aortic surgery. This review serves to summarise the current practice of spinal cord protection during surgery of the descending thoracoabdominal aortic surgery. The pathophysiology of s pinal cord ischaemia will also be explained. The incidence of spinal cord i schaemia and subsequent neurological complications was associated with (1) the duration and severity of ischaemia, (2) failure to establish spinal cor d supply and (3) reperfusion injury. The blood supply of the spinal cord ha s been extensively studied and the significance of the artery of Adamkiewic z (ASA) being recognised. This helps us to understand the pathophysiology o f spinal cord ischaemia during descending and thoracoabdominal aortic opera tion. Techniques of monitoring of spinal cord function using evoked potenti al have been developed. Preoperative identification of ASA facilitates the identification of critical intercostal vessels for reimplantation, resultin g in re-establishment of spinal cord blood flow. Different surgical techniq ues have been developed to reduce the duration of ischaemia and this includ es the latest transluminal techniques. Severity of ischaemia can be minimis ed by the use of CSF drainage, hypothermia, partial bypass and the use of a djunctive pharmacological therapy. Reperfusion injury can be reduced with t he use of anti-oxidant therapy. The aetiology of neurological complications after descending and thoracoabdominal aortic surgery has been well describ ed and attempts have been made to minimise this incidence based on our know ledge of the pathophysiology of spinal cord ischaemia. However, our underst anding of the development and prevention of these complications require fur ther investigation in the clinical setting before surgery on descending and thoracoabdominal aorta to be performed with negligible occurrence of these disabling neurological problems. (C) 2001 Elsevier Science B.V. All rights reserved.