Eeg Monitoring During Carotid Endarterectomy

Abstract

One hundred and thirty‐one patients undergoing 142 carotid endarterectomy procedures were randomized to have their operation performed either with or without intra‐operative electroencephalographic (EEG) monitoring. Patients with EEG monitoring were shunted if both the internal carotid back pressure (ICBP) was less than 50 mmHg and ipsilateral change was evident on the EEG after clamping. Patients without EEG monitoring were shunted if ICBP was less than 50 mmHg. There was one postoperative death (0.7%) with neurological deficits occurring in five patients (3.5%). There were significantly fewer neurological deficits (P = 0.02) in patients with no EEG change (one of 59) compared with those with EEG change (two of 13). There was a highly significant increase (P = 0.005) in incidence of neurological deficit (two of five patients) when ICBP was considered ‘adequate’ at 50 mmHg or greater but EEG change occurred. No neurological deficit occurred in 14 patients who were not shunted with ICBP < 50 mmHg but with no EEG change. There was no difference in the incidence of neurological deficit in patients with low and high ICBP when both 50 and 55 mmHg were used as the cut‐off points. It is concluded that EEG monitoring is useful in identifying patients requiring shunting during carotid endarterectomy. Use of a shunt is recommended if there is EEG change regardless of ICBP; conversely, if ICBP is low but there is no EEG change it would appear safe to proceed without shunting.

Routine or Selective Carotid Artery Shunting for Carotid Endarterectomy (and Different Methods of Monitoring in Selective Shunting)

“…10 The treatment groups were comparable, but the method of randomization, blinding of outcome assessment, and duration of follow-up were unclear. Three of 72 (4.1%) patients in the combined monitoring group had ipsilateral strokes within 24 hours of surgery compared with 2 out of 70 (2.9%) in the stump pressure alone group (ORϭ1.47, 95% CIϭ0.25 to 8.68, Pϭ0.7).…”

Prospective randomized trial of routine versus selective shunting in carotid endarterectomy based on stump pressure

“…34 They also cite the advantage of shunting in helping carotid artery closure. 7,10,29 Because most patients undergoing carotid surgery do not require a shunt to maintain adequate cerebral perfusion, the use of selective shunting has been advocated.…”

“…10,11,16,17,[19][20][21] Some surgeons also believe that shunting aids in closure of the carotid arteries, whereas others believe the presence of shunt makes closure more difficult. 7,10,29 It has also been suggested that for those surgeons who use shunts only selectively, the relative infrequent use of the shunt makes its use more hazardous than with experienced surgeons.…”

“…[9][10][11]14,16,17 Some have suggested a systolic stump pressure of Ͻ50 mm Hg and Ͻ40 mm Hg, and others selected a mean stump pressure of 50, 45, 40, or 25 mm Hg. A few randomized trials have compared routine vs selective shunting during CEA, 8,13,29 but none were based on stump pressure. This is the first randomized CEA trial to compare the results of routine shunting vs selective shunting based on carotid stump pressure.…”

Routine or Selective Carotid Artery Shunting for Carotid Endarterectomy and Different Methods of Monitoring in Selective Shunting

“…7 The treatment groups were comparable, but the method of randomization, blinding of outcome assessment, and duration of follow-up were unclear. Three of 72 patients in the combined monitoring group had ipsilateral strokes …”