Peculiarities of cerebral blood flow in patients with chronic diffuse liver diseases of viral etiology
Aim. To study the features of cerebral blood flow at different structural and functional levels of the brain vascular system in patients with chronic hepatitis and cirrhosis of viral etiology. Methods. A comprehensive ultrasound examination of the brain vascular system using an algorithm of cerebral arterial and venous blood flow examination based on the concept of the brain vascular system construction considering five structural and functional levels was performed in 65 chronic viral hepatitis patients and 61 patients with liver cirrhosis of viral etiology. The examination of the main brain arteries was performed using duplex scanning ultrasound SSD-5500 scanner («Aloka», Japan) with 5-12 MHz linear transducers. Examination of intracranial vessels was performed by transcranial color duplex scanning using ultrasonic SSD-5500 and «Sonoline G60» scanners («Siemens», Germany) with linear and phased 2.1-2.5 MHz transducers. Control group consisted of 50 healthy persons. Results. Remodeling of the cerebral arteries: the expansion of the lumen of the main cerebral vessels, reduction of blood flow in the carotid and middle cerebral arteries, decreased elasticity and increased vascular wall rigidity and, as a consequence, a change in vascular resistance and cerebral blood flow disturbance occurs in patients with chronic viral liver diseases. Identified changes of blood flow parameters at all levels of structural and functional brain perfusion indicate the presence of cerebral microangiopathy and arteriopathy based on the development of arteriosclerosis of main arteries and all penetrating arteries and arterioles in patients with chronic diffuse liver diseases. Conclusion. Adaptive remodeling of the vascular wall of the main cerebral arteries which provides an adequate regulatory response is found in patients with hepatitis B and C-associated liver cirrhosis. The reduction of blood supply to the brain, depletion of functional vascular reserve and development of intracranial venous circulatory distress are seen in patients with liver cirrhosis associated with viral hepatitis.