Paraplegia caused by spinal cord ischemia remains a devastating complication after surgical repair of thoracoabdominal aortic aneurysms. Cerebrospinal fluid (CSF) drainage has been advocated as a protective adjunct to reduce the incidence of postoperative neurologic deficits. Studies in animals have shown that CSF drainage during thoracic aortic clamping reduces CSF pressure, improves spinal cord blood flow, and prevents paraplegia. Previous retrospective and randomized clinical studies, however, have been inconclusive because of confounding factors and other limitations. A recent prospective randomized trial focusing solely on CSF drainage during repair of extent I and II thoracoabdominal aortic aneurysms indicated an 80% reduction in the relative risk of paraplegia and paraparesis in patients who received this adjunct. Consequently, CSF drainage has emerged as an important addition to the multimodality strategy for preventing postoperative spinal cord deficits.