15. REDUCTION OF CERVICAL SURGICAL MORBIDITY AND MORTALITY WITH INTRAOPERATIVE SOMATOSENSORY EVOKED POTENTIAL (SEP) MONITORING

Abstract Objective Clamping of the internal carotid artery (ICA) during carotid endarterectomy (CEA) is a critical step. In our neurosurgical department, CEAs are performed with transcranial Doppler (TCD) and somatosensory evoked potential (SEP) monitoring with a 50% flow velocity/amplitude decrement warning criteria for shunting. The aim of our study was to evaluate our protocol with immediate neurologic deficits after surgery for the primary end point. Methods This is a single-center retrospective cohort study of symptomatic and asymptomatic ICA stenosis patients from January 2012 to June 2015. Only those cases in which CEA was performed with both modalities (TCD and SEP) were included. The Mann-Whitney U test was applied to evaluate TCD and SEP ratios based on immediate postoperative neurologic deficits. Results A total of 144 patients were included, 120 (83.3%) with symptomatic ICA stenosis. The primary end point was met by six patients (4.2%); all of them were patients with a symptomatic ICA stenosis. The stroke and death rate was 1.4%. Ratios of SEP amplitudes demonstrated significant differences between patients with and without an immediate postoperative neurologic deficit at the time of ICA clamping (p = 0.005), ICA clamping at 10 minutes (p = 0.044), and ICA reperfusion (p = 0.005). Ratios of TCD flow velocity showed no significant difference at all critical steps. Conclusion In this retrospective series of simultaneous TCD and SEP monitoring during CEA surgery of predominantly symptomatic ICA stenosis patients, the stroke and death rate was 1.4%. SEP seemed to be superior to TCD in predicting the need for an intraoperative shunt and for predicting temporary postoperative deficits. Further prospective studies are needed.

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Observations on intraoperative somatosensory evoked potential (SEP) monitoring in the semi-sitting position

Clinical Neurophysiology ◽

10.1016/s1388-2457(02)00302-4 ◽

2002 ◽

Vol 113 (12) ◽

pp. 1993-1997 ◽

Cited By ~ 11

Author(s):

Helmut Wiedemayer ◽

Heike Schaefer ◽

W Armbruster ◽

M Miller ◽

Dietmar Stolke

Keyword(s):

Evoked Potential ◽

Somatosensory Evoked Potential ◽

Sitting Position ◽

Sep Monitoring

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Intraoperative monitoring of blood flow insufficiency during surgery of middle cerebral artery aneurysms

Journal of Neurosurgery ◽

10.3171/jns.2005.103.2.0275 ◽

2005 ◽

Vol 103 (2) ◽

pp. 275-283 ◽

Cited By ~ 102

Author(s):

Kazuomi Horiuchi ◽

Kyouichi Suzuki ◽

Tatsuya Sasaki ◽

Masato Matsumoto ◽

Jun Sakuma ◽

...

Keyword(s):

Blood Flow ◽

Middle Cerebral Artery ◽

Cerebral Artery ◽

Evoked Potential ◽

Control Level ◽

The Other ◽

Somatosensory Evoked Potential ◽

Content Type ◽

Sep Monitoring ◽

Fine Print

Object. The usefulness of motor evoked potential (MEP) monitoring to detect blood flow insufficiency (BFI) in the cortical branches of the middle cerebral artery (MCA) and lenticulostriate arteries (LSAs) during MCA aneurysm surgery was investigated based on the correlation between MEP and somatosensory evoked potential (SEP) monitoring. Methods. Fifty-three patients with MCA aneurysms underwent surgery accompanied by intraoperative MEP and SEP monitoring. There was no postoperative motor paresis in 43 patients in whom MEP and SEP results remained unchanged. In the other 10 patients, nine manifested transient MEP changes; in five of these, SEP changes did not occur. The transient MEP changes were thought to be attributable to BFI of the MCA cortical branches in two patients, the LSA in three, and either the MCA branches or the LSA in four patients. Of these nine patients, six did not present with postoperative motor paresis; transient motor paresis was recognized in the other three. In the 10th patient, MEP waves disappeared and did not recover. This patient's SEPs remained at 70% of the control level, and he developed severe hemiparesis. A postoperative computerized tomography scan revealed a new low-density area in the corona radiata and putamen. Conclusions. Blood flow insufficiency in both the LSA and MCA cortical branches that perfuse the corticospinal tract can be detected by intraoperative MEP monitoring. Somatosensory evoked potential monitoring is not reliable enough to detect BFI in the MCA branches and the LSAs.

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Comparison of time–frequency analysis techniques in intraoperative somatosensory evoked potential (SEP) monitoring

Computers in Biology and Medicine ◽

10.1016/s0010-4825(01)00026-9 ◽

2002 ◽

Vol 32 (1) ◽

pp. 13-23 ◽

Cited By ~ 13

Author(s):

Yong Hu ◽

Keith Dipkei Luk ◽

William Weijia Lu ◽

John Chiyan Leong

Keyword(s):

Frequency Analysis ◽

Evoked Potential ◽

Somatosensory Evoked Potential ◽

Time Frequency Analysis ◽

Time Frequency ◽

Analysis Techniques ◽

Sep Monitoring

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Reversible Somatosensory Evoked Potential Changes with Neodymium: Yttrium-Aluminum-Garnet Laser Use

Neurosurgery ◽

10.1227/00006123-198710000-00004 ◽

1987 ◽

Vol 21 (4) ◽

pp. 465-467 ◽

Cited By ~ 5

Author(s):

Randall R. Long ◽

Fremont P. Wirth

Keyword(s):

Nd:Yag Laser ◽

Evoked Potential ◽

Yttrium Aluminum Garnet ◽

Tissue Injury ◽

Foramen Magnum ◽

Dorsal Column ◽

Somatosensory Evoked Potential ◽

Tissue Temperature ◽

Yttrium Aluminum ◽

Sep Monitoring

Abstract Reversible prolongation and dissolution of the tibial somatosensory evoked potential (SEP) was observed with operative use of the neodymium:yttrium-aluminum-garnet (Nd:YAG) laser during extirpation of a foramen magnum meningioma. Rapid normalization of the SEP followed irrigation with cool saline. The absence of postoperative dorsal column deficit suggests that heat-related physiological changes occurred before the point of irreversible tissue injury. Should intraoperative SEP monitoring prove a reliable index of tissue temperature, it could enable safer use of the Nd:YAG laser in the vicinity of the spinal cord and brain stem.

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