Strategies for Preventing Spinal Cord Ischemia During Descending or Thoracoabdominal Aortic Aneurysm Surgery: Preoperative Visualization of the Adamkiewicz Artery and Intraoperative Motor-Evoked Potentials

Abstract

We report here our recent strategies for preventing spinal cord ischemia during surgery for descending or thoracoabdominal aortic aneurysms. A total of 25 patients underwent replacement of the thoracoabdominal or descending aorta. The age of the patients ranged from 29 to 83 years (59.4 ± 12.8 years), and the male/female ratio was 18:7. Sixteen patients had nondissecting aneurysms and nine had aortic dissection. Twenty-one patients underwent open surgery, and four patients underwent endovascular stent-graft repair. Preoperative magnetic resonance angiography (MRA) was used to visualize the Adamkiewicz artery, and there were intraoperative recordings of myogenic motor-evoked potentials (MEP) using a transcranial stimulator. Femorofemoral bypass with a heparin-coated circuit under mild hypothermia (30°-32°C) was used. The Adamkiewicz arteries were demonstrated in 18 patients (72%); they originated from the left intercostal or lumbar arteries in 13 (72%) patients, from the right intercostal or lumban arteries in 5 (28%), and from the T8 branch in 2, T9 in 7, T10 in 2, T11 in 2, T12 in 1, and L1 in 2. The MEPs were recorded in 22 patients (88%). In 10 patients there was a transient decrease of the potentials, although the amplitude resumed after reconstructing the intercostal arteries or after rewarm-ing. Two patients died of graft infections and bowel necrosis (7.1%) after open surgery; there was no spinal cord injury among the survivors. We concluded that preoperative detection of the Adamkiewicz artery by MRA and intraoperative MEP monitoring were useful for reducing the incidence of spinal cord injury during surgery for aneurysms of the thoracoabdominal or descending aorta.