Abstract WP123: Determinants Of Cerebral Hyperperfusion Syndrome After Extracranial-intracranial Artery Bypass In Severe Intracranial Steno-occlusive Disease
Background: Patients with intracranial stenoses are at considerable risk for ischemic events. Recent trials on stenting for intracranial stenoses and external carotid-internal carotid (EC-IC) bypass in carotid occlusions failed to show benefit over best medical therapy. We perform EC-IC bypass in patients with severe steno-occlusive disease of intracranial internal carotid (ICA) or middle cerebral artery (MCA) with impaired cerebral vasodilatory reserve (CVR). EC-IC bypass may lead to cerebral hyperperfusion syndrome (HPS) in some cases, presenting as neurological deficits during early post-operative period. We evaluated possible predictors of HPS.
Methods: Patients with severe intracranial ICA or MCA stenosis and impaired CVR on transcranial Doppler (TCD) derived breath-holding index (BHI) were evaluated with acetazolamide-challenged 99Tc-HMPAO-SPECT. Patients with significantly impaired CVR on SPECT were offered EC-IC bypass with close post-operative monitoring.
Results: Of the 112 patients with severe intracranial ICA/MCA stenosis, 77 (69%) showed impaired CVR and 46 (41%) underwent STA-MCA bypass. Transient neurological deficits, mainly contralateral weakness within 7-days of surgery, were noted in 8 (17%). HPS was confirmed by CT perfusion and/or SPECT in 7 cases. Strong correlation was observed between HPS and pre-operative TCD-BHI (0% cases with BHI 0.3-0.69; 6.3% with BHI 0-0.3 and 41% with BHI <0, p=0.012). HPS patients showed more than 50% increase in the MCA mean flow velocity on TCD (compared to pre-operative values) on the operated side (63.3% vs 3.3% on control side, p<0.0005). Meticulous control of blood pressure and hydration led to complete resolution of neurological deficits in all cases (mean 3-days, range 1-6days).
Conclusion: Symptomatic cerebral HPS is common in early post-operative period after EC-IC bypass surgery. Early diagnosis and appropriate management might prevent the complications of this syndrome
- © 2012 by American Heart Association, Inc.