Transcranial doppler microembolus detection in the identification of patients at high risk of perioperative stroke

Levi, Christopher; Roberts, Anne; Fell, Gary; Hoare, Michael C.; Royle, John P.; Chan, Andrew K.; Beiles, Barry; Bladin, Christopher; Donnan, Geoffrey A.

doi:10.1016/s1078-5884(97)80187-6

Cited by 34 publications

(25 citation statements)

References 20 publications

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“…[3][4][5][6] Microembolic signals (MES) detected by transcranial Doppler (TCD) are associated with an increased risk of stroke and new ischemic lesions on MR scans after CEA. [7][8][9][10][11][12] In our previous study, Ͼ50 MES per hour detected during the first postoperative hour was significantly associated with new ischemic neurological deficits. 13 At present, factors involved in the generation of MES are poorly understood.…”

Section: T He European Carotid Surgery Trial (Ecst) and Northmentioning

confidence: 80%

Possible Determinants of Early Microembolism After Carotid Endarterectomy

Stork

Levi

Chambers

et al. 2002

Stroke

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Background and Purpose-High numbers of microembolic signals (MES) have been associated with increased risk of postoperative stroke after carotid endarterectomy (CEA). We sought to identify factors predictive of postoperative MES. Methods-Transcranial Doppler monitoring of the ipsilateral middle cerebral artery for MES was performed for 30 minutes during the first postoperative hour in sequential patients undergoing CEA. Stepwise binomial logistic regression analysis was performed to identify preoperative and intraoperative variables that predicted the occurrence of postoperative MES. Results-We studied 141 patients (mean age, 69 years); 102 (72%) were male, and 69 (49%) had at least 1 MES (range, 1 to 118) detected in the first postoperative hour. The risk of postoperative MES was greater in women (Pϭ0.027), patients not receiving antiplatelet therapy (Pϭ0.033), and patients undergoing left-sided CEA (Pϭ0.049). Other variables such as residual stenosis seen on completion angiography and operative technique were not associated with postoperative MES. Conclusions-Postoperative MES were most likely in women, patients not receiving preoperative antiplatelet therapy, and patients who had a left CEA. Microembolism might explain why these same factors are associated with higher rates of perioperative stroke.

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Section: T He European Carotid Surgery Trial (Ecst) and Northmentioning

confidence: 80%

Possible Determinants of Early Microembolism After Carotid Endarterectomy

Stork

Levi

Chambers

et al. 2002

Stroke

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“…Perioperative TCD monitoring has shown that cerebral microemboli are common in patients undergoing carotid surgery [6, 7, 8, 9, 10, 11]. Most of these emboli enter the cerebral circulation without producing any significant or permanent clinical deficit after the operation.…”

Section: Discussionmentioning

confidence: 99%

Temporary Occlusion of MiddleCerebral Artery by Macroembolism inCarotid Surgery

Claus

Louwerse²,

Mauser

et al. 1999

Cerebrovasc Dis

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Two patients are presented who during carotid endarterectomy (CEA) temporarily showed an obstruction of the middle cerebral artery (MCA) mainstem by a macroembolus resulting in cerebral ischaemia. Both cases are unusual examples of CEA and selected from a cohort of more than 1,500 operations. During surgery with general anaesthesia, brain function was monitored with computerized electroencephalography (EEG) and transcranial Doppler (TCD) ultrasonography. The simultaneous use of EEG and TCD monitoring allowed us to witness the development of intraoperative cerebral ischaemia and to relate these events to a temporary occlusion of the MCA mainstem by a macroembolus. This is the first life report that describes obstruction of a cerebral artery by arterial embolism resulting in cerebral ischaemia.

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“…Nineteen studies, with a total of 5570 individual patients, reported stroke as an outcome along with data for TCD recording of microembolic signals (7)(8)(9)(10)13,16,(18)(19)(20)23,(27)(28)(29)(30)(31)(32)(33)(34). The sensitivity and specificity were 73.14 (95% CI 48.16 to 88.86) and 70.27 (95% CI 58.61 to 79.78)* respectively.…”

Section: Strokementioning

confidence: 99%