Protection from postischemic spinal cord injury by perfusion cooling of the epidural space during most or all of a descending thoracic or thoracoabdominal aneurysm repair

Objective: It is reported that hypothermia has some protective effect against ischemia of the spinal cord during thoracoabdominal aneurysm repair. However, it has not been elucidated clinically whether regional spinal cord hypothermia by epidural perfusion cooling is effective and safe. The purpose of this study was to assess the effect and safety of perfusion cooling of the epidural space during most or all of descending thoracic or thoracoabdominal aneurysm repair. Methods: From January 1998 to December 2007, a total of 102 patients with a mean age of 61 years underwent replacement of most or all of the descending thoracic aorta or thoracoabdominal aorta with the aid of mild hypothermia via epidural perfusion cooling and cerebrospinal fluid (CSF) drainage. Risk factors for spinal cord injury and hospital death were analyzed using univariate and multivariate analyses. The actuarial survival rate was calculated by the Kaplan-Meier method. Results. The mean lowest CSF temperature was 23.3°C during epidural perfusion cooling. The mean temperature difference between the nasopharynx and CSF was 8.4°C. The incidence of spinal cord injury was 3.9% (4/102), and that of hospital death was 5.9% (6/102). There was no significant risk factor associated with spinal cord injury. Type III aneurysm and postoperative cerebrovascular accident, respiratory failure, liver failure, and infection were predictors of hospital death. The actuarial survival rates at 3 and 5 years were 82.1% and 75.9%, respectively. Conclusion: Epidural perfusion cooling is a safe method to employ in clinical situations. Our contemporary management strategies enabled patients to undergo thoracoabdominal aneurysm repair with excellent early and late survival and acceptable morbidity.