The primary objective of this study is to evaluate if the motor-evoked potentials/motor action potential amplitude ratio and motor action potential amplitude measurement are useful in detecting spinal cord ischemia during thoracoabdominal aortic aneurysms surgery.

The secondary objective is to evaluate the presence of a correlation between neurophysiological changes and other factors (such as surgical maneuvers, anesthetic and physiologic changes) in order to find which factor is the most important in determining spinal cord ischemia.

This study is an observational, single-center, prospective study on patients with thoracoabdominal aortic aneurysms undergoing surgical repair with intraoperative motor-evoked potentials and somatosensory evoked potentials monitoring.

Inclusion Criteria:

• satisfied criteria for Intraoperative neurophysiological monitoring;
• sign a written informed consent to participate in the study.

Exclusion Criteria:

• No exclusion criteria

The study population will consist of all consecutive patients with thoracoabdominal aortic aneurysms who will be subjected to neuromonitoring-guided open repair of the aortic aneurysm at the Department of Vascular Surgery of San Raffaele Hospital.