Estimating Hemodynamic Significant Deformations of Brachiocephalic Arteries Using CT Perfusion

Background and Aim: The cause of most strokes is associated with the pathology of the carotid arteries. Many modern researchers suggest preventive surgery in the presence of arterial deformity to prevent strokes. The hemodynamic significance of carotid deformities is determined by morphological and functional disorders at the level of tortuosity, the reaction of cerebral blood flow is not often considered. Here, we assume that cerebral autoregulation in tortuosity can be different. Methods and Materials/Patients: A total of 64 patients (31-75 years old) with 110 carotid deformities were analyzed. Duplex color mapping, computed tomography angiography of carotid arteries, and computed tomography perfusion were performed by estimating the absolute and average values of cerebral blood flow (mL/100 g/min), cerebral blood volume (mL/100 g), Mean transit time (MTT) (s) in similar areas of the cortex. In 6 patients, the acetazolamide challenge test was used to evaluate the autoregulatory disturbances. Results: According to computed tomography angiography and duplex color mapping, 18(28.1%) patients had unilateral tortuosity, and 46(71.9%) patients had bilateral tortuo s ity. Hemodynamically significant deformities were detected in 33 cases (30% of tortuosity). In 54 cases (49% of tortuosity), the deformities were accompanied by carotid stenosis. Perfusion disorders were detected in 23 of 64 patients (35.9%). In the majority of cases (75% of all perfusion disorders), hypoperfusion was diagnosed on the side corresponding to the maximum degree of stenosis, regardless of the location of the tortuosity. Neurologically significant hypoperfusion, compensated by collateral blood flow revealed only in 7.8% of cases of hemodynamic significant internal carotid artery deformity without concomitant atherosclerosis. Conclusion: The decision on surgical correction of carotid artery tortuosity should be made while considering both local changes in hemodynamics and proven violations of autoregulation of cerebral blood flow, especially in patients with concomitant carotid stenosis

ВОЗМОЖНОСТИ ХИРУРГИЧЕСКОЙ КОРРЕКЦИИ ТРОМБОЗА ВНУТРЕННЕЙ СОННОЙ АРТЕРИИ У ПАЦИЕНТОВ С ОСТРЫМ ИШЕМИЧЕСКИМ ИНСУЛЬТОМ

Objective. To estimate the efficacy of surgical treatment of internal carotid artery (ICA) thrombosis in patients suffered from acute ischemic stroke (AIS).Material and methods. Author operated 25 patients suffered from AIS and ICA thrombosis from 01 Feb, 2014 till 31 Aug, 2016 in Neurosurgical Department of N.V. Sklifosovsky Research Institute for Emergency Medicine. Among them, 15 patients had total thrombosis of ICA and were operated on, 10 patients had partial mural thrombosis or floating thrombus (6 patients were operated on). There were 7 thrombectomies with the removal of intima, 13 superficial temporal artery (STA)-middle cerebral artery (MCA) bypasses, 1 ICA stent installation.Results. The excellent outcomes were seen in 7 (33.4%) patients, good outcomes — in 11 (52.3%) and satisfactory outcomes were observed in 3 (14.3%) patients. The improvement of functional deficit in the early post-operative period was 4.85 scores according to NIHSS, 1.2 scores according to Rankin scale and 2.3 scores according to Rivermead mobility index. The regress of neurological deficit was more significant among patients with severe focal disturbances; better outcomes were among patients operated on within first 3 days from an onset of the disease. There was no significant improvement among non-operated patients at the moment of discharge from hospital. Thrombectomy with the removal of intima performed in 2 (40%) patients with partial mural thrombosis was complicated by repeated thrombosis of ICA. The improvement of cerebral blood supply was verified in 16 (76.2%) operated patients according to the data of cerebral perfusion examination.Conclusions. The early surgical treatment is indicated for patients with acute total thrombosis of ICA. It is possible to perform STA-MCA bypass in case of inability to perform endovascular thrombextraction or open thrombectomy with the removal of intima. The conservative treatment is indicated for patients with partial mural thrombosis while urgent operation is necessary among patient with floating thrombus to decrease the risk of cerebral embolism. Цель. Оценить эффективность хирургического лечения тромбоза внутренней сонной артерии (ВСА) у пациентов с острым ишемическим инсультом (ОИИ).Материал и методы. В период с 1.02.2014 по 31.08.2016 гг. в нейрохирургическом отделении НИИ СП им. Н.В. Склифосовского пролечены 25 пациентов с ОИИ и тромбозом ВСА. У 15 больных выявлен полный тромбоз (все 15 оперированы), у 10 — неполный пристеночный или флотирующий тромб (6 оперированы). Выполнено 7 тромбинтимэктомий (ТИЭ), 13 экстра-интракраниальных микроанастомозов (ЭИКМА), одно стентирование ВСА. Результаты. Отличные исходы получены у 7 (33,4%), хорошие — у 11 (52,3%), удовлетворительные — у 3 (14,3%) больных. Снижение функционального дефицита в раннем послеоперационном периоде состави- ло 4,85 балла по шкале NIHSS, 1,2 балла по шкале Рэнкина и 2,3 балла по индексу мобильности Ривермид. Регресс неврологического дефицита был более выражен у пациентов со значительными очаговыми нарушениями; лучшие исходы имели пациенты, оперированные в первые 3 сут заболевания. У неоперированных пациентов достоверного улучшения к моменту выписки не было. ТИЭ по поводу пристеночных тромбозов в 2 наблюдениях (40%) сопровождалась ретромбозом ВСА. У 16 оперированных пациентов (76,2%) отмечено улучшение кровоснабжения головного мозга по данным исследований его перфузии.Заключение. Пациентам с острым полным тромбозом ВСА показано проведение раннего хирургического лечения. При невозможности проведения эндовазальной тромбэкстракции или открытой ТИЭ предлагается выполнить обходное шунтирование (ЭИКМА). Пациентам с неполным пристеночным тромбозом показано проведение консервативного лечения. Больным с неполным флотирующим тромбозом и высоким риском эмболии в головной мозг показано проведение экстренной операции.

POSSIBILITIES OF SURGICAL CORRECTION OF INTERNAL CAROTID ARTERY THROMBOSIS IN PATIENTS WITH ACUTE ISCHEMIC STROKE

Objective. To estimate the efficacy of surgical treatment of internal carotid artery (ICA) thrombosis in patients suffered from acute ischemic stroke (AIS).Material and methods. Author operated 25 patients suffered from AIS and ICA thrombosis from 01 Feb, 2014 till 31 Aug, 2016 in Neurosurgical Department of N.V. Sklifosovsky Research Institute for Emergency Medicine. Among them, 15 patients had total thrombosis of ICA and were operated on, 10 patients had partial mural thrombosis or floating thrombus (6 patients were operated on). There were 7 thrombectomies with the removal of intima, 13 superficial temporal artery (STA)-middle cerebral artery (MCA) bypasses, 1 ICA stent installation.Results. The excellent outcomes were seen in 7 (33.4%) patients, good outcomes — in 11 (52.3%) and satisfactory outcomes were observed in 3 (14.3%) patients. The improvement of functional deficit in the early post-operative period was 4.85 scores according to NIHSS, 1.2 scores according to Rankin scale and 2.3 scores according to Rivermead mobility index. The regress of neurological deficit was more significant among patients with severe focal disturbances; better outcomes were among patients operated on within first 3 days from an onset of the disease. There was no significant improvement among non-operated patients at the moment of discharge from hospital. Thrombectomy with the removal of intima performed in 2 (40%) patients with partial mural thrombosis was complicated by repeated thrombosis of ICA. The improvement of cerebral blood supply was verified in 16 (76.2%) operated patients according to the data of cerebral perfusion examination.Conclusions. The early surgical treatment is indicated for patients with acute total thrombosis of ICA. It is possible to perform STA-MCA bypass in case of inability to perform endovascular thrombextraction or open thrombectomy with the removal of intima. The conservative treatment is indicated for patients with partial mural thrombosis while urgent operation is necessary among patient with floating thrombus to decrease the risk of cerebral embolism