MSCT PERFUSION IN ASSESSMENT OF BRAIN HEMODYNAMICS AND IN ANALYSIS OF SURGICAL TREATMENT RESULTS IN PATIENTS WITH CHRONIC BRAIN ISHEMIA

Background: Stenoses of the brachiocephalic arteries (BCA) are ones of the main causes of ischemic defects of cerebral circulation. From the end of the former century to the current time, the surgical cerebral revascularization in steno-occlusive BCA disturbances occupies the topical place in prevention of acute brain circulation defects. Carotid endarterectomy (CEAE) remains till now a basic method of surgical revascularization. As a result of chronic hypoperfusion, autoregulation of the cerebral circulation can be disturbed with a persistent capillary dilatation which enables development of hyperperfusion syndrome after surgical intervention. Aim: A quantitative assessment of the cerebral tissue perfusion disturbances depending on the variants of the brachiocephalic vessels lesions before and after surgical reconstructions as well as revealing possible prerequisites for hyperperfusion syndrome development during preoperative multislice computed tomography (MSCT) perfusion. Materials and methods: The results of examination and treatment of 65 patients (mean age 64.2±5.0 years) with chronic cerebrovascular IV stage insufficiency were analyzed as well as the hemodynamically significant lesion of the inner carotid arteries. CEAE was planned for all patients. All patients underwent cerebral MSCT angiography and MSCT perfusion in preoperative and early postoperative periods. Results: The majority of patients in preoperative period showed decrease of perfusion parameters at the side of the most expressed defects. The mean circulation deficiency varied from 12 to 15%. Improvement of circulation at the side of surgical intervention formed, on the average, about 12%. The best outcome was noted in patients with bilateral stenoses of the inner carotid arteries (ICA). In one case, in critical unilateral ICA stenosis in preoperative period, MSCT perfusion demonstrated persisting dilatation of the small cerebral arteries of the disturbed hemisphere which led to autoregulation defects of these arteries with a high risk of hyperperfusion syndrome development. On the second day of the postoperative period, the said hyperperfusion syndrome developed but was successfully arrested using hypotensive therapy. Conclusion: CEAE provides circulation improvement in patients with ischemic stroke. MSCT perfusion favors circulation improvement in ischemic stroke patients. MSCT perfusion allows revealing patients with high risk of hyperperfusion syndrome development in postoperative period.