ИСТИНА

Background: Assessment of perioperative complication risks of carotid endarterectomy (CEA) for patients with contralateral internal carotid artery (ICA) occlusion can affect surgical tactics, but still remains controversial. Especially it is important for patients with neurological symptoms and persistent severe cerebrovascular insufficiency (CVI) on the side of ICA occlusion, who are candidates for staged STA-MCA bypass surgery. This study is devoted to perioperative risk evaluation of CEA considering the severity of CVI on the side of symptomatic contralateral ICA occlusion. Methods: Since 2006 overall 97 patients with severe ICA stenoses and symptomatic contralateral carotid occlusions underwent CEA - it is 6% of all performed CEA at this period. Staged STA-MCA bypasses were performed for 43 patients (44%) with persistent CVI according to ultrasound and CT perfusion (CTP) studies - hemispheric MTT > 10sec (>180% MTT increase over intact hemisphere) with exhausted cerebrovascular reserves. For cerebral protection during carotid clumping we used temporary indwelling shunt in 32 cases (33%) according to selective criteria, based on multimodality neuromonitoring techniques(TCD, EEG and cerebral oximetry) and neurological testing (by regional anesthesia). Results: We distinguished all patients in to groups according to severity of CVI on the side of occlusion. Patient with signs of blood flow compensation on the side of contralateral occlusion had significantly less rate of carotid clamping intolerance – 11% of shunt use as during usual CEA despite no morbidity during surgery. No additional cerebral revascularization was performed. Nevertheless severe perfusion deficit on the side of ICA occlusion (>180% MTT increase over intact hemisphere, ore more than 10sec.) increased the risk of CEA – indications for shunt use were revealed in 51% of cases, especially for patients without severe carotid stenosis (<80%) on the side of CEA – carotid clamping intolerance was up to 73% . All patients in this group underwent staged STA-MCA bypass surgery. Overall 3 patients with moderate carotid stenoses in this group (6,9%) had ischemic complications after CEA – in one case - contralateral ischemic stroke (on the side of occlusion), in 2 cases - minor strokes on the side of CEA. Wherein patients with preventive STA-MCA bypass before CEA didn’t suffered from any complications. Conclusions: Surgical risk of CEA for patients with symptomatic contralateral ICA occlusion depends probably on the severity of perfusion deficit. For patients with moderate carotid stenoses (<80%) and symptomatic subacute contralateral carotid occlusion CTP is recommended. For patients with severe perfusion deficit on the side of carotid occlusion STA-MCA bypass can decrease possible CEA complication rates.