Neuromonitoring in vascular surgery
Vascular surgery
Vascular surgery deals with the surgical treatment of blood vessels in general and also includes the treatment of vessels supplying the brain in the case of arteriosclerosis. The forms of treatment in vascular surgery often include the use of vascular bypasses for peripheral arterial disease or the insertion of prostheses for the treatment of aneurysms.
Importance of neuromonitoring in vascular surgery
In contrast to most other application fields, neuromonitoring is used indirectly in vascular surgery to obtain information about the perfusion of the tissue to be monitored by recording mostly somatosensory evoked potentials (SEPs). In this case, signal changes in the SEP recording can provide information about the changes in the vessels.
Neuromonitoring during the treatment of carotid artery stenosis in vascular surgery
This is particularly relevant in carotid surgery during the treatment of carotid artery stenosis (carotid endarterectomy). In this case, the temporary occlusion of the carotid artery can lead to reduced perfusion of the brain, which leads to changes in the SEPs. Intraoperative neuromonitoring allows cerebral ischaemia to be detected at an early stage, enabling surgeons to adapt their surgical approach accordingly.[1]
Neuromonitoring during the treatment of thoracic and thoracoabdominal aortic aneurysms in vascular surgery
Another major application field for neuromonitoring in vascular surgery is thoracic and thoracoabdominal aortic aneurysm surgery. In advanced aneurysms, for example, a rupture or dissection may occur, which is associated with a high mortality rate for patients.[2]
Continuously recorded somatosensory evoked potentials as well as motor evoked potentials (MEPs) can efficiently indicate the beginning of spinal ischaemia during thoracic and thoracoabdominal aortic interventions within vascular surgery.[3]
The ischaemic processes that have an effect on the function of the motor and sensory pathways are reflected in changes in the MEP and SEP signals.[4] With MEP and SEP measurements, spinal neuromonitoring in vascular surgery offers better risk protection during these life-saving interventions.
References
1. Branston, N. M., Symon, L., Crockard, H. A. & Pasztor, E. Relationship between the cortical evoked potential and local cortical blood flow following acute middle cerebral artery occlusion in the baboon. Exp. Neurol. 45, 195–208 (1974).
2. Cambria, R. P. et al. A multicenter clinical trial of endovascular stent graft repair of acute catastrophes of the descending thoracic aorta. J. Vasc. Surg. 50, 1255–1264.e4 (2009).
3. Genstorfer, J. et al. Evozierte Potentiale in der Aortenchirurgie. Zeitschrift für Herz-, Thorax-, und Gefäßchirurgie 16, 149–155 (2005).
4. Hartert, M. et al. Klinische Anwendung evozierter Potentiale und neuroprotektiver Maßnahmen in der Aortenchirurgie. Zeitschrift für Herz-, Thorax- und Gefäßchirurgie 19, 239–251 (2005).