Extended Motor Evoked Potentials Monitoring Helps Prevent Delayed Paraplegia After Aortic Surgery

Area of Science:

• Neurosurgery
• Vascular Surgery
• Neuromonitoring

Background:

• Motor evoked potentials (MEPs) monitoring aids in detecting spinal cord ischemia (SCI) during open thoracoabdominal aneurysm repair (OTAAR).
• While MEPs monitoring during aortic clamping and absence of immediate postoperative SCI (IP-SCI) are positive indicators, they do not eliminate the risk of delayed postoperative SCI (DP-SCI).

Purpose of the Study:

• To investigate whether extending MEPs monitoring beyond the aortic clamp interval (ACI) can reduce the incidence of DP-SCI.
• To determine the independent effect of extended MEPs monitoring on DP-SCI risk.

Main Methods:

• A retrospective analysis of 150 patients undergoing OTAAR with distal aortic perfusion (DAP) and MEPs monitoring between April 2005 and October 2014 was conducted.
• Patients with no IP-SCI were analyzed for DP-SCI development.
• Logistic regression and propensity score analysis were used to assess the impact of extended MEPs monitoring, adjusting for potential confounders.

Main Results:

• Of 150 patients, 129 (86%) had no neurological deficits, while 21 (14%) developed DP-SCI.
• Nineteen of the 21 patients (90%) with DP-SCI did not have extended MEPs monitoring.
• Extended MEPs monitoring was associated with a significantly decreased risk of DP-SCI (odds ratio = 0.14; p = 0.01).

Conclusions:

• Extended MEPs monitoring is independently associated with a lower risk of developing DP-SCI after OTAAR.
• Postoperative MEPs monitoring can guide hemodynamic management to ensure adequate spinal cord perfusion, especially when neurological exams are unreliable.