Background: Spinal cord ischemia is one of the most serious complications after an aortic repair. To date, there is no evidence for arterial changes during an aortic dissection or for the observation of such arteries after an aortic repair. The aim of this study was to compare spinal-cord-supplying arteries in patients with an acute aortic dissection, preoperatively and postoperatively, with patients without an acute aortic dissection. Methods: Preoperative and postoperative contrast-enhanced computed tomography scans of 25 patients who had undergone the frozen elephant trunk procedure to treat an aortic dissection and 25 patients who qualified for a transcatheter aortic valve replacement without an acute aortic dissection and atherosclerosis of the analyzed vessels, treated as a control group, were reconstructed and retrospectively analyzed with the detailed medical data of the patients. The aortic branches with the ability to supply blood to the spinal cord as described in the literature were further analyzed. Results: The preoperative arterial diameters of the left internal thoracic artery, the left musculophrenic artery, and the left and right supreme intercostal arteries were significantly larger compared to the postoperative measurements. In addition, the preoperative measurements of the diameters of the left vertebral artery, right internal thoracic artery, left lateral thoracic artery, and left common iliac artery were significantly larger than in the control group. Conclusions: The internal thoracic arteries and supreme intercostal arteries may play a crucial role in providing additional blood supply to the spinal cord.