Utility of intraoperative Motor Evoked Potential monitoring in thoracic endovascular aortic repair

P0371 

Abstract Submission 

Shinichi Imai (1), Hiroyuki Otsuka (1), Seiji Onitsuka (1), Atsutoshi Tanaka (1), Ryo Kanamoto (1), Yusuke Shintani (1), Takahiro Shojima (1), Kazuyosi Takagi (1), Toru Takaseya (1), Shinichi Hiromatsu (1), Eiki Tayama (1)

(1) Department of Surgery, Division of Cardiovascular Surgery, Kurume University School of Medicine, Kurume, 67 Asahi-machi

Shinichi Imai    -  Contact Me
Department of Surgery, Division of Cardiovascular Surgery, Kurume University School of Medicine

Hiroyuki Otsuka    -  Contact Me
Department of Surgery, Division of Cardiovascular Surgery, Kurume University School of Medicine

Seiji Onitsuka    -  Contact Me
Department of Surgery, Division of Cardiovascular Surgery, Kurume University School of Medicine

Atsutoshi Tanaka    -  Contact Me
Department of Surgery, Division of Cardiovascular Surgery, Kurume University School of Medicine

Ryo Kanamoto    -  Contact Me
Department of Surgery, Division of Cardiovascular Surgery, Kurume University School of Medicine

Yusuke Shintani    -  Contact Me
Department of Surgery, Division of Cardiovascular Surgery, Kurume University School of Medicine

Takahiro Shojima    -  Contact Me
Department of Surgery, Division of Cardiovascular Surgery, Kurume University School of Medicine

Kazuyosi Takagi    -  Contact Me
Department of Surgery, Division of Cardiovascular Surgery, Kurume University School of Medicine

Toru Takaseya    -  Contact Me
Department of Surgery, Division of Cardiovascular Surgery, Kurume University School of Medicine

Shinichi Hiromatsu    -  Contact Me
Department of Surgery, Division of Cardiovascular Surgery, Kurume University School of Medicine

Eiki Tayama    -  Contact Me
Department of Surgery, Division of Cardiovascular Surgery, Kurume University School of Medicine

Shinichi Imai    -  Contact Me
N/A

Objective:
Thoracic endovascular aortic repair (TEVAR) has emerged as an alternative to traditional open repair. However, neurologic complications remain a risk. Spinal cord ischemia (SCI) is the most devastating complication after TEVAR. Although motor evoked potential (MEP) monitoring is used to assess intraoperative spinal cord viability, it is not clear whether perioperative MEP monitoring decreases SCI. We retrospectively investigate patients who had undergone TEVAR in our institution to assess the association of intraoperative MEP monitoring with postoperative paraplegia.

Methods:
We retrospectively examined 81 patients (64 males, mean age of 74.2 ± 7.8 years old) who underwent TEVAR with MEP monitoring, excluding cases of emergency surgery, at Kurume University Hospital between 2015 and 2022. MEP was recorded on the skin overlying the abductor pollicis brevis muscle and tibialis anterior muscles. A significant reduction in MEP amplitude was defined as a decrease in the peak-to-peak amplitude of at least 10% relative to the baseline. MEP changes occurred in 11 patients (14%) during TEVAR. We compared the 11 patients with MEP changes to the 71 patients without MEP changes.

Results:
Underlying pathologies included descending thoracic aortic aneurysm in 41 (51%) patients, and type B aortic dissection in 20 (25%) patients. No significant differences in patient characteristics were observed between the two groups, except for males. The proportion of past abdominal aortic repair and bleeding during TEVAR were higher in patients with MEP changes than those in patients without MEP changes. The two groups had no differences in the proportion of artery of Adamkiewicz (AKA) coverage, left subclavian artery (LSCA) coverage, and internal iliac artery (IIA) occlusion. Three (3.7%) of the patients who underwent TEVAR had delayed paraplegia, and two of them had MEP changes. One of the patients without MEP changes had delayed paraplegia. Preoperative cerebrospinal fluid (CSF) drainage caused spinal cord compression by subdural hematoma. The incidence of SCI was significantly higher in patients with MEP changes than in patients without MEP changes (18% vs 1%, p=0.0293).
Six (17%) of the 36 patients who underwent TEVAR with AKA coverage had MEP changes, and one of them had delayed paraplegia. Five (11%) of 45 patients who underwent TEVAR without AKA coverage had MEP changes, one of which had delayed paraplegia. Nine (82%) of 11 patients who had MEP changes showed reduction of MEP after stent graft deployment, and two of them had delayed paraplegia. In all patients with MEP changes, raising blood pressure using dopamine and administration of blood transfusion resulted in spontaneous recovery of MEP.

Conclusions:
MEP changes during TEVAR had high sensitivity and specificity for SCI. Therefore, intraoperative MEP monitoring may be a useful tool in detecting spinal cord ischemia in TEVAR patients.

Spinal Cord Protection