No abstract

The main aim of the study was to investigate the effect of carotid endarterectomy on the prognosis of chronic cerebral ischemia in patients with symptomatic occlusions of the contralateral internal carotid artery, assess risks of surgical complications, and substantiate the staged surgical approach for treatment of patients with this pathology. The article analyzes the experience in surgical treatment of 83 patients with symptomatic ICA occlusions who underwent surgery for contralateral carotid artery stenosis. In 40 patients, only carotid endarterectomy (CEA) was performed on the side of hemodynamically significant stenosis (group 1). In 43 (52%) cases, apart from CEA, extracranial-intracranial (EC-IC) bypass was performed at the second stage (23 cases, group 2) or the first stage (19 cases, group 3). A surgical treatment approach was chosen based on clinical symptoms, severity of contralateral carotid artery stenosis, and the magnitude of perfusion deficiency in the territory of carotid occlusion. The conducted analysis revealed that patients with symptomatic occlusions and contralateral carotid artery stenoses represented a heterogeneous group with a different efficacy of carotid endarterectomy and with risks of perioperative complications. As cerebrovascular insufficiency in the territory of carotid occlusion and a related neurological deficit worsen, the risks of complications of contralateral carotid endarterectomy increase, and its clinical efficacy decreases. In these cases, cerebral revascularization on the ICA occlusion side should be performed at the first stage.

Context: Physiological insights into blood flow alterations in cortical vessels after superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery are important for the prognosis of bypass sustainability and hemodynamic patency. Aims: This study aims to assess the impact of STA-MCA bypass on local hemodynamics for patients with symptomatic carotid occlusions and Moyamoya disease. Settings and Design: This article presents a prospective nonrandomized study of intraoperative blood flow measurements in cortical branches of MCA and donor vessel before and after cerebral revascularization. Materials and Methods: Evaluation of local hemodynamic parameters was established for 112 patients with symptomatic carotid occlusive disease and cerebrovascular insufficiency during STA-MCA bypass surgery. We used intraoperative Doppler ultrasonography (89 patients – 72%), flowmetry (56 cases – 50%), and in 33 cases both methods. For physical justification of observed facts, we performed computational simulation with OpenFOAM CFD framework using Navier-Stokes nonstationary hemodynamic model. Statistical Analysis Used: All calculations were performed with IBM SPSS Statistics version 10.0 software. We used parametric ( Z -test and Student's t -test) and nonparametric models (Wilcoxon, Mann–Whitney). For categorical values, we used Fisher's exact test. Results: Local cerebral hemodynamics after revascularization surgery significantly depended on initial perfusion deficit and the ability of bypass to reverse the blood flow in proximal parts of cortical artery (86 cases, 77%). Mechanism of cortical blood flow alteration was related to donor vessel cut flow value and potential consumption threshold of acceptor artery. Conclusions: Knowledge of hemodynamic principles of flow redistribution after STA-MCA bypass is important to improve bypass stainability and leads to better revascularization results.

No abstract

No abstract