Vascular surgeries involving blood supply to the brain or spinal cord may place these structures at risk. IONM is useful in carotid endarterectomy (CEA) - a surgical procedure used to prevent stroke -, by correcting narrowing in the common carotid artery (arteries that provide the main blood supply to the brain, located on each side of your neck under the jawline). In these cases, it helps to show adequate blood supply to the brain from adjacent arteries during the surgery or alerts the surgeon to place a bypass tube (shunt) to improve blood flow when needed. IONM has also been able to predict spinal cord injury from reduced blood flow during aortic aneurism resection (repairing an abnormal widening or ballooning of the major artery in the chest and abdomen), where it may also help to identify major arterial feeders to the spinal cord during their selective temporary obstruction. Several authors support use of monitoring of one type or another to guard against injuries caused by decrease blood flow to the brain during cardiac bypass procedures.

Selected References
Halsy, JH. Risks and benefits of shunting in carotid endarterectomy. The international Transcranial Doppler Collaborators. Stroke 1992;23;1583-87 Quinones-Baldrich WJ, Moore WS.Intraoperative monitoring and use of the internal shunt during carotid endarterectomy. Int Surg. 1984 Jul-Sep;69(3):207-13.

Prokop A, Meyer GP, Walter M, Erasmi H. Validity of SEP monitoring in carotid surgery. Review and own results. J Cardiovasc Surg (Torino). 1996 Aug;37(4):337-42.