Usefulness of Transcranial Motor Evoked Potentials During Thoracoabdominal Aortic Surgery

Kobe University, Kōbe, Hyōgo, Japan
The Annals of thoracic surgery (Impact Factor: 3.85). 03/2007; 83(2):456-61. DOI: 10.1016/j.athoracsur.2006.09.056
Source: PubMed


The purpose of this study was to evaluate the efficacy of myogenic transcranial motor evoked potentials (tc-MEPs) for spinal cord ischemia in the repair of descending thoracic or thoracoabdominal aortic aneurysms.
Intraoperative tc-MEPs was used in 72 patients who underwent the repair of descending thoracic (n = 24) or thoracoabdominal aortic aneurysms (n = 49) classed as Crawford I in 10 patients, II in 12, III in 23, and IV in 3. There were 52 men and 20 women, and their mean age was 64.9 +/- 12.8 years. Tc-MEPs were recorded by transcranial electrical stimulation and compound muscle action potentials.
The hospital mortality rate was 5.6% (n = 4), and the incidence of neurologic deficits was 11.1% (n = 8). All patients whose MEP amplitude recovered to more than 75% of the baseline showed normal spinal function, and 8 of 9 patients whose MEP amplitude decreased to below 75% of the baseline at the end of the procedure showed neurologic deficits postoperatively. The sensitivity of tc-MEPs was 100% and specificity was 98.4%. Latency in patients with postoperative paraplegia was 123% +/- 9% and was significantly prolonged at the end of the procedure.
Tc-MEPs were very sensitive and specific to spinal cord ischemia with reduced amplitude and prolongation of the latency period. Tc-MEPs are considered a useful monitor of spinal cord ischemia during descending thoracic or thoracoabdominal aortic surgery.


Available from: Hiroshi Tanaka, Feb 19, 2015
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    • "In addition, intraoperative monitoring of spinal cord potentials, such as motor-evoked potentials (MEPs), evoked spinal cord potentials (ESCPs), and somatosensory evoked potentials (SSEPs) have been used to assess spinal cord function during surgery [5—10]. However, when spinal cord potentials are monitored, the incidence of paraplegia following thoracic and thoracoabdominal aortic surgery ranges from 4.2% to 11.3% [5] [7] [8]. "
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