Cerebral Hemodynamics in Symptomatic and Asymptomatic Patients with Severe Unilateral Carotid Stenosis before and after Carotid Endarterectomy

Telman, Gregory; Kouperberg, Efim; Nitecki, Sami; Karram, T.; Schwarz, Henry; Sprecher, Elliot; Hoffman, Aaron; Yarnitsky, David

doi:10.1016/j.ejvs.2006.04.031

Cited by 29 publications

(24 citation statements)

References 20 publications

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“…However, patients with symptomatic carotid artery stenosis may lack adequate collateral circulation and experience strokes or transient ischemic attacks; 4,21,25–27 these patients rely more heavily on reducing peripheral cerebral resistance to maintain adequate perfusion of the cerebral hemispheres. 20,34,36 …”

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confidence: 99%

“…22 The PI is often documented to be ≥ 1.0 in asymptomatic CEA patients and < 1.0 in symptomatic CEA patients, indicating reduced peripheral cerebral resistance and likely a degree of cerebral autoregulatory exhaustion. 31,34,36,38 Symptomatic patients with a baseline PI < 1.0 prior to CEA often demonstrate increased CBF after plaque removal and flow restoration. 5,6,19,20,30,31,34,36–38 …”

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confidence: 99%

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Middle cerebral artery pulsatility index and cognitive improvement after carotid endarterectomy for symptomatic stenosis

Heyer

Mergeche²,

Connolly

2014

JNS

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Object Transcranial Doppler (TCD) is frequently used to evaluate peripheral cerebral resistance and cerebral blood flow (CBF) in the middle cerebral artery prior to and during carotid endarterectomy (CEA). Patients with symptomatic carotid artery stenosis may have reduced peripheral cerebral resistance to compensate for inadequate CBF. The authors aim to determine whether symptomatic patients with reduced peripheral cerebral resistance prior to CEA demonstrate increased CBF and cognitive improvement as early as 1 day after CEA. Methods Fifty-three patients with symptomatic CEA were included in this observational study. All patients underwent neuropsychometric evaluation 24 hours or less preoperatively and 1 day postoperatively. The MCA was evaluated using TCD for CBF mean velocity (MV) and pulsatility index (PI). Pulsatility index ≤ 0.80 was used as a cutoff for reduced peripheral cerebral resistance. Results Significantly more patients with baseline PI ≤ 0.80 exhibited cognitive improvement 1 day after CEA than those with PI > 0.80 (35.0% vs 6.1%, p = 0.007). Patients with cognitive improvement had a significantly greater increase in CBF MV than patients without cognitive improvement (13.4 ± 17.1 cm/sec vs 4.3 ± 9.9 cm/sec, p = 0.03). In multivariate regression model, a baseline PI ≤ 0.80 was significantly associated with increased odds of cognitive improvement (OR 7.32 [1.40–59.49], p = 0.02). Conclusions Symptomatic CEA patients with reduced peripheral cerebral resistance, measured as PI ≤ 0.80, are likely to have increased CBF and improved cognitive performance as early as 1 day after CEA for symptomatic carotid artery stenosis. Revascularization in this cohort may afford benefits beyond prevention of future stroke. Clinical trial registration no: NCT00597883 (ClinicalTrials.gov).

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Middle cerebral artery pulsatility index and cognitive improvement after carotid endarterectomy for symptomatic stenosis

Heyer

Mergeche²,

Connolly

2014

JNS

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“…These observations are in line with previously published results by Telman and Reinhard. 18,20, 21 It may be argued that abrogation of carotid artery stenosisevoked cerebral hypoperfusion by CEA is critically involved in the improvement of cerebral autoregulation. However, the improvement of autoregulation was independent of changes in cerebral blood flow indicating differential mechanistic and etiological effects of CEA on cerebral function and hemodynamics.…”

Section: Cea and Baroreflex Sensitivitymentioning

confidence: 99%

“…15 Cerebral autoregulation is impaired in carotid artery stenosis [16][17][18][19] and is partly restored by CEA. 20, 21 In the present study, we aimed to verify the short-term effect of CEA on BRS using a novel statistical algorithm specifically validated for baroreflex calculation. 22, 23 Furthermore, we assessed cerebral autoregulation in patients with carotid artery stenosis before and after CEA.…”

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confidence: 99%

Autonomic Function and Cerebral Autoregulation in Patients Undergoing Carotid Endarterectomy

Mense¹,

Reimann²,

Rüdiger³

et al. 2010

Circ J

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Background: Carotid endarterectomy (CEA) is the first-line treatment in severe carotid stenosis to prevent stroke. Because of methodological limitations, the acute impact of CEA on baroreflex function and cerebral autoregulation is not well defined and was therefore investigated by applying a novel algorithm. Methods and Results:Systemic arterial blood pressure, ECG and respiration during metronomic breathing and Valsalva maneuver were continuously recorded in 18 patients with carotid stenosis before and after CEA, and in 10 healthy controls. Baroreflex sensitivity, frequency spectra of RR intervals and indices for cerebral autoregulation were evaluated by trigonometric regressive spectral analysis. Compared with the controls, patients had impaired baroreflex sensitivity. Baroreflex sensitivity and frequency spectra were not changed by CEA. Cerebral autoregulation of patients with carotid stenosis as calculated by phase shift was reduced compared with controls but it improved significantly after CEA. Improvement of cerebral autoregulation was independent of changes in cerebral blood flow velocity. Conclusions:Baroreflex sensitivity and cerebral autoregulation are impaired in patients with carotid stenosis, conferring a high stroke risk. CEA improves cerebral autoregulation, but does not affect baroreflex sensitivity. For further risk reduction, interventional approaches targeting baroreflex function need to be considered. (Circ J 2010; 74: 2139 - 2145

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“…Many authors reported that the identification of a given degree of stenosis alone is no longer sufficient to identify patients at high risk for developing stroke [16,17,18,19]. Ultrasound can determine the so-called vulnerable plaque by estimation of its echolucency or the presence of an irregular surface.…”

Section: How Should the Degree Of Carotid Stenosis Be Assessed?mentioning

confidence: 99%

Endarterectomy, Best Medical Treatment or Both for Stroke Prevention in Patients with Asymptomatic Carotid Artery Stenosis

Cardona¹,

Rubio²,

Martínez-Yélamos³

et al. 2007

Cerebrovasc Dis

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Carotid endarterectomy (CEA) is currently frequently performed in subjects with asymptomatic carotid artery stenosis over 70%, as clinical trials like the Asymptomatic Carotid Atherosclerosis Study and Asymptomatic Carotid Surgery Trial demonstrated a significant benefit for stroke prevention. A low risk reduction in the long-term prevention of stroke or death and the required lower than 3% of surgical risk are associated with surgery. That means that an important number of patients needs to be operated to prevent 1 stroke over 5 years (number needed to treat: 21) with an absolute risk reduction of 5.4%. It is reasonable to consider CEA for patients aged 40–75 years and with asymptomatic stenosis of 60–99%, for patients with a life expectancy of at least 5 years, and in centres with a surgical morbidity-mortality of less than 3%. Therefore, it is of interest to identify high-risk patients with asymptomatic carotid stenosis who will more likely benefit from surgery. Techniques such as ultrasound or magnetic resonance imaging may identify plaque morphology or detect clinically asymptomatic embolization. CEA combined with the best medical treatment and good management of modifiable risk factors might be superior to medical management alone or surgery in preventing stroke. There is no level I evidence to support carotid artery stenting in asymptomatic carotid stenosis even in a subgroup of patients with a high surgical risk.

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Cerebral Hemodynamics in Symptomatic and Asymptomatic Patients with Severe Unilateral Carotid Stenosis before and after Carotid Endarterectomy

Abstract: The exhausted ability of cerebral autoregulation is an important factor differentiating between symptomatic and asymptomatic patients with severe carotid stenosis. Successful surgery provides good recovery of cerebral hemodynamics in both symptomatic and asymptomatic patients.

Cited by 29 publications

References 20 publications

Middle cerebral artery pulsatility index and cognitive improvement after carotid endarterectomy for symptomatic stenosis

Middle cerebral artery pulsatility index and cognitive improvement after carotid endarterectomy for symptomatic stenosis

Autonomic Function and Cerebral Autoregulation in Patients Undergoing Carotid Endarterectomy

Endarterectomy, Best Medical Treatment or Both for Stroke Prevention in Patients with Asymptomatic Carotid Artery Stenosis

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