Changes in cerebral hemodynamic and cognitive parameters after external carotid–internal carotid bypass surgery in patients with severe steno-occlusive disease: A pilot study



      The direct impact of external carotid–internal carotid (EC-IC) bypass surgery on cognition of patients with severe steno-occlusive disease of internal carotid (ICA) or middle cerebral artery (MCA) is unknown. In this pilot study, we evaluated changes in cerebral hemodynamic and cognition in these patients.


      Patients with severe steno-occlusive disease and impaired cerebral vasodilatory reserve (CVR) with transcranial Doppler (TCD) breath holding index (BHI) and acetazolamide-challenged HMPAO-Single Photon Emission Tomographic (SPECT) imaging were offered EC-IC bypass surgery. CVR and cognitive performance using a formal neuropsychological battery were evaluated before and 3–6 months after surgery.


      Nine patients and 9 matched controls were recruited. Significant CVR improvement from TCD-BHI [median 0 (Inter-quartile range IQR 0.45) to 1.10 (IQR 0.73), p<0.001] and SPECT (p<0.001) was observed in surgery patients. EC-IC bypass patients had significant improvement in verbal memory (p=0.037) and executive function (p=0.043) and a trend of improvement in visual memory (p=0.052) compared to controls.


      EC-IC bypass surgery in carefully selected patients could improve cerebral hemodynamics and verbal memory and executive function.


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        • Wong L.K.S.
        Global burden of intracranial atherosclerosis.
        Int J Stroke. 2006; 1: 158-159
        • Wong K.S.
        • Li H.
        Long-term mortality and recurrent stroke risk among Chinese stroke patients with predominant intracranial atherosclerosis.
        Stroke. 2003; 34: 2361-2366
        • Tham W.
        • Auchus A.P.
        • Thong M.
        • Goh M.L.
        • Chang H.M.
        • Wong M.C.
        • et al.
        Progression of cognitive impairment after stroke: one year results from a longitudinal study of Singaporean stroke patients.
        J Neurol Sci. 2002; 203–204: 49-52
        • Nys G.M.
        • van Zandvoort M.J.
        • de Kort P.L.
        • Jansen B.P.
        • de Haan E.H.
        • Kappelle L.J.
        Cognitive disorders in acute stroke: prevalence and clinical determinants.
        Cerebrovasc Dis. 2007; 23: 408-416
        • Nys G.M.
        • van Zandvoort M.J.
        • van der Worp H.B.
        • de Haan E.H.
        • de Kort P.L.
        • Jansen B.P.
        • et al.
        Early cognitive impairment predicts long-term depressive symptoms and quality of life after stroke.
        J Neurol Sci. 2006; 247: 149-156
        • Yasargil M.G.
        Diagnosis and indications for operations in cerebrovascular occlusive disease.
        in: Yasargil M.G. Microsurgery Applied to Neurosurgery. Georg Thieme Verlag, Stuttgart1960: 95-119
        • Karasawa J.
        • Kikuchi H.
        • Furuse S.
        • Kawamura J.
        • Sakaki T.
        Treatment of moyamoya disease with STA-MCA anastomosis.
        J Neurosurg. 1978; 49: 679-688
        • EC/IC Bypass Surgery Group
        Failure of extracranial-intracranial arterial bypass to reduce the risk of ischemic stroke: results of an international randomized trial.
        N Engl J Med. 1985; 313: 1191-1200
        • Powers W.J.
        • Clarke W.R.
        • Grubb Jr., R.L.
        • Videen T.O.
        • Adams Jr., H.P.
        • Derdeyn C.P.
        • et al.
        Extracranial-intracranial bypass surgery for stroke prevention in hemodynamic cerebral ischemia: the Carotid Occlusion Surgery Study randomized trial.
        JAMA. 2011; 306: 1983-1992
        • Fiedler J.
        • Přibáň V.
        • Škoda O.
        • Schenk I.
        • Schenková V.
        • Poláková S.
        Cognitive outcome after EC-IC bypass surgery in hemodynamic cerebral ischemia.
        Acta Neurochir. 2011; 153: 1303-1312
        • Sharma V.K.
        • Wong K.S.
        Intracranial stenosis.
        in: Alexandrov A.V. Cerebrovaswcular ultrasound in stroke prevention and treatment. Wiley Blackwell Publishing Ltd., Oxford UK2011: 228-239
        • Rathakrishnan R.
        • Berne Y.I.
        • Quek K.K.
        • Hong C.S.
        • Ong B.K.C.
        • Chan B.P.L.
        • et al.
        Validation of transcranial Doppler with CT angiography in cerebral ischemia: a preliminary pilot study in Singapore.
        Ann Acad Med Singapore. 2008; 37: 402-405
        • Markus H.S.
        • Harrison M.J.
        Estimation of cerebrovascular reactivity using transcranial Doppler, including the use of breath-holding as the vasodilatory stimulus.
        Stroke. 1992; 23: 668-673
        • Hirano T.
        • Minematsu K.
        • Hasegawa Y.
        • Tanaka Y.
        • Hayashida K.
        • Yamaguchi T.
        Acetazolamide reactivity on 123I-IMP single photon emission computed tomography in patients with major cerebral artery occlusive disease: correlation with positron emission tomography parameters.
        J Cereb Blood Flow Metab. 1994; 14: 763-770
        • Sharma V.K.
        • Tsivgoulis G.
        • Ning C.
        • Teoh H.L.
        • Bairaktaris C.
        • Chong V.F.
        • et al.
        Role of multimodal evaluation of cerebral hemodynamics in selecting patients with symptomatic carotid or middle cerebral artery steno-occlusive disease for revascularization.
        J Vasc Interv Neurol. 2008; 1: 96-101
        • Dong Y.H.
        • Sharma V.K.
        • Chan B.P.-L.
        • Venketasubramanian N.
        • Teoh H.L.
        • Seet R.C.S.
        • et al.
        The Montreal Cognitive Assessment (MoCA) is superior to the Mini-Mental State Examination (MMSE) for the detection of Vascular Cognitive Impairment after Acute Stroke.
        J Neurol Sci. 2010; 299: 15-18
        • Dong Y.H.
        • Venketasubramanian N.
        • Chan B.P.-L.
        • Sharma V.K.
        • Slavin M.J.
        • Collinson S.L.
        • et al.
        Brief screening tests during acute admission in patients with mild stroke are predictive of vascular cognitive impairment 3-6 months after stroke.
        J Neurol Neurosurg Psychiatry. 2012;
        • Folstein M.F.
        • Folstein S.E.
        • McHugh P.R.
        “Mini Mental State”—a practical method for grading the cognitive state of patients for the clinician.
        J Psychiatr Res. 1975; 12: 189-198
        • Nasreddine Z.S.
        • Phillips N.A.
        • Bédirian V.
        • Charbonneau S.
        • Whitehead V.
        • Collin I.
        • et al.
        The Montreal Cognitive Assessment, MoCA: a brief screening tool for mild cognitive impairment.
        J Am Geriatr Soc. 2005; 53: 695-699
        • Yeo D.
        • Gabriel C.
        • Chen C.
        • Lee S.
        • Loenneker T.
        • Wong M.
        Pilot validation of a customized neuropsychological battery in elderly Singaporeans.
        Neurol J South East Asia. 1997; 2: 123
        • Dubois B.
        • Litvan I.
        The FAB: a frontal assessment battery at bedside.
        Neurology. 2000; 55: 1621-1626
        • Lee J.Y.
        • Phi J.H.
        • Wang K.C.
        • Cho B.K.
        • Shin M.S.
        • Kim S.K.
        Neurocognitive profile of children with Moyamoya disease before and after surgical intervention.
        Cerebrovasc Dis. 2011; 31: 230-237
        • Arbuthnott K.
        • Frank J.
        Trail making test: part B as a measure of executive control: validation using a set-switching paradigm.
        J Clin Exp Neuropsychol. 2000; 22: 518-528
        • Lin M.S.
        • Chiu M.J.
        • Wu Y.W.
        • Huang C.C.
        • Chao C.C.
        • Chen Y.H.
        • et al.
        Neurocognitive improvement after carotid artery stenting in patients with chronic internal carotid artery occlusion and cerebral ischemia.
        Stroke. 2011; 42: 2850-2854
        • Pendlebury S.
        • Rothwell P.
        Prevalence, incidence, and factors associated with pre-stroke and post-stroke dementia: a systematic review and meta-analysis.
        Lancet Neurol. 2009; 8: 1006-1018