Cerebral microembolism and ischemic changes associated with carotid endarterectomy

Cantelmo, Nancy L.; Babikian, Viken L.; Samaraweera, Ranji; Gordon, Jonathan K.; Pochay, Val E.; Winter, Michael

doi:10.1016/s0741-5214(98)70005-9

Cited by 89 publications

(66 citation statements)

References 26 publications

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“…The rate of postoperative silent infarction was higher than in CT-based reports and ranged from 0% to 24%. 8,12,13,33 Still higher rates of silent ischemia would probably have been demonstrated in these MRI studies if they had been supplemented by diffusion-weighted sequences. In the present series, the probability of missing postoperative ischemic lesions was particularly small because DWI was performed in the first 24 hours after the operation to detect any short-lived cerebral changes.…”

Section: Discussionmentioning

confidence: 94%

“…Very high percentages (up to 95%) have been reported by several groups of investigators. 5,[7][8][9][10][11][12][13] Exclusion of the sonographic signals that occur at and immediately after declamping greatly reduces the overall rate of detected microemboli. In one study considering only emboli occurring at flow restoration, a rate as low as 5% was reported along with what were considered to be flow turbulence signals in 40% of cases.…”

Section: Discussionmentioning

confidence: 99%

“…Several studies using transcranial Doppler (TCD) monitoring have measured a prevalence of embolic signals as high as 95% during CEA. 5,[7][8][9][10][11][12][13] It has been suggested that increased cerebral microembolization may positively correlate with postoperative deterioration of cognitive function or the appearance of lacunar infarcts on MRI. 7,8 However, the clinical relevance of sonographic embolic signals remains unclear because most of them are not associated with focal neurological deficits.…”

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confidence: 99%

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Silent Cerebral Ischemia Detected by Diffusion-Weighted MRI After Carotid Endarterectomy

Barth

Remonda

Lövblad

et al. 2000

Stroke

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Background and Purpose-Small emboli arising from a friable plaque during carotid endarterectomy (CEA) constitute an important risk of perioperative ischemic complications. To evaluate the incidence and significance of silent cerebral ischemic lesions of embolic origin after CEA, we prospectively examined a series of surgical patients with high-grade carotid stenosis by using diffusion-weighted MRI (DWI). We also tried to correlate postoperative ischemic lesions with the occurrence of sonographic cerebral embolic signals, the presence of plaque ulcerations, and the use of intraoperative shunting. Methods-Of a consecutive series of 53 patients undergoing elective CEA for high-grade carotid stenosis, 48 patients with unchanged postoperative neurological status were prospectively studied with DWI of the brain the day before and the day after the operation. The magnetic resonance images were analyzed by 2 neuroradiologists blinded to the clinical result of the operation. Any new hyperintense signal was interpreted as a postoperative ischemic lesion. Results-Forty-six (95.8%) of 48 patients had unchanged postoperative brain DWI. In 2 patients (4.2%), a new single asymptomatic hyperintense signal was observed on the side of the operation. Both lesions were small and presumably of embolic origin. They were not related to sonographic embolic signals, plaque ulcerations, or intraoperative shunting. Conclusions-These results suggest that the incidence of silent ischemic brain lesions of embolic origin after CEA is low and does not correlate with the occurrence of intraoperative sonographic microemboli. They confirm that CEA is a safe procedure that carries a low risk of postoperative cerebral events. (Stroke. 2000;31:1824-1828.)

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Section: Discussionmentioning

confidence: 94%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

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Silent Cerebral Ischemia Detected by Diffusion-Weighted MRI After Carotid Endarterectomy

Barth

Remonda

Lövblad

et al. 2000

Stroke

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“…3,[5][6][7][8] The actual number of patients with high-grade embolization is Ͻ5%, 4 but of these 30% to 60% will progress to thrombotic stroke. 3,5 Postoperative TCD monitoring and selective administration of dextran-40 has been successful in reducing embolization and progression to stroke.…”

Section: See P 1442mentioning

confidence: 99%

Beneficial Effects of Clopidogrel Combined With Aspirin in Reducing Cerebral Emboli in Patients Undergoing Carotid Endarterectomy

et al. 2004

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Background-Postoperative thromboembolic stroke affects 2% to 3% of patients undergoing carotid endarterectomy (CEA) and is preceded by 1 to 2 hours of increasing cerebral embolization. Previous work has demonstrated that high rates of postoperative embolization are associated with increased platelet reactivity to adenosine 5Ј-diphosphate (ADP). Our hypothesis was that preoperative administration of the platelet ADP antagonist clopidogrel could reduce postoperative embolization. Methods and Results-One hundred CEA patients on routine aspirin therapy (150 mg) were randomized to 75 mg clopidogrel (nϭ46) or placebo (nϭ54) the night before surgery. Platelet response to ADP was assessed by whole-blood flow cytometry. The number of emboli detected by transcranial Doppler within 3 hours of CEA was independently quantified. Time taken from flow restoration to skin closure was used as an indirect measure of the time to secure hemostasis. In comparison with placebo, clopidogrel produced a small (8.8%) but significant reduction in the platelet response to ADP (PϽ0.05) while conferring a 10-fold reduction in the relative risk of those patients having Ͼ20 emboli in the postoperative period (odds ratio, 10.23; 95% CI, 1.3 to 83.3; Pϭ0.01, Fisher's exact test). However, in the clopidogrel-treated patients, the time from flow restoration to skin closure (an indirect marker of hemostasis) was significantly increased (Pϭ0.04, Fisher's exact test), although there was no increase in bleeding complications or blood transfusions. Conclusions-This is the first study to show that a CEA patient's postoperative thromboembolic potential can be significantly reduced by targeted preoperative antiplatelet therapy without increasing the risk of bleeding complications.

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“…4,9,13) Most perioperative neurological complications are ischemic complications caused by hemodynamic hypoperfusion, which is considered to be relatively rare, and emboli released from the fragile plaque during arterial dissection or cross-clamping. 3,10,12) Therefore, the most common strategy to prevent ischemia during CEA is selective shunt usage based on the findings of electroencephalography (EEG), stump pressure, or transcranial Doppler sonography, to reduce the risk of embolic complication resulting from shunt device insertion or removal, 2,11,16) as shunting carries the risk of embolus release. 6,12,17) However, the intraoperative decisionmaking for selective shunt usage following monitoring changes during cross-clamping requires vast experience.…”

Section: Introductionmentioning

confidence: 99%

Incidence of Ischemic Lesions by Diffusion-Weighted Imaging After Carotid Endarterectomy With Routine Shunt Usage

Inoue

Tsutsumi

Maeda³

et al. 2006

Neurol. Med. Chir.(Tokyo)

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Temporary intraluminal shunt was used during 72 consecutive carotid endarterectomies (CEAs) in 61 patients (bilateral CEA in 11 patients) during October 2001 and September 2005. The medical records of these patients were retrospectively reviewed. All procedures were performed with routine shunt insertion without monitoring such as electroencephalography. Pre-and postoperative diffusion-weighted magnetic resonance (MR) imaging was used to detect ischemic complications. Postoperative angiography was performed in 70 cases to detect abnormalities such as major stenosis or dissection of the distal end. Symptomatic ischemic complication occurred in one patient at 1 month. Postoperative diffusion-weighted MR imaging detected new hyperintense lesions in three patients including the symptomatic patient. Postoperative angiography confirmed that the distal end was satisfactory in all cases. The incidence of ischemic lesions of embolic origin after CEA with routine shunt usage is acceptably low if the procedure of shunt device insertion and removal is meticulously conducted.

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Cerebral microembolism and ischemic changes associated with carotid endarterectomy

Abstract: Ischemic changes on MRI after CEA are related to postoperative MS.

Cited by 89 publications

References 26 publications

Silent Cerebral Ischemia Detected by Diffusion-Weighted MRI After Carotid Endarterectomy

Silent Cerebral Ischemia Detected by Diffusion-Weighted MRI After Carotid Endarterectomy

Beneficial Effects of Clopidogrel Combined With Aspirin in Reducing Cerebral Emboli in Patients Undergoing Carotid Endarterectomy

Incidence of Ischemic Lesions by Diffusion-Weighted Imaging After Carotid Endarterectomy With Routine Shunt Usage

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