Features of portal hemodynamics in patients with fatty liver disease: mechanisms of formation, clinical significance

Abstract

There are few data in the literature on the state of portal and hepatic blood flow in patients with fatty liver disease, and portal hemodynamics at the pre-cirrhotic stage is practically not covered. The aim of the study was to study the features of portal hemodynamics in patients with fatty liver disease at the pre-cirrhotic stage. Materials and methods. The study included 43 patients (25 - patients with fatty liver disease and 18- a comparison group who applied to outpatient clinics of therapeutic profile aged 18-89 years (41.9% of men, 58.1% of women). The average age of the patients was 45.1± 19.4 years. Criteria for inclusion in the study: age 18 years and older; presence of fatty liver disease associated with metabolic conditions. Criteria for not being included in the study: the presence of viral hepatitis, alcoholic liver disease, autoimmune liver diseases, pregnancy, lactation, taking any medications, narcotic drugs, the presence of acute or exacerbation of chronic diseases. The anthropometric indicators of patients were evaluated: waist circumference (OT), body mass index (BMI), steatotic indices (St-index, Fatty Liver Index), liver fibrosis index (Fib 4). Portal hemodynamics was assessed using ultrasound Dopplerography on a Philips Affiniti 50 device. Sensor C5-1. The following criteria were evaluated: vessel diameter (mm), its cross-sectional area (PPP, cm2), time-averaged maximum velocity (TAMX, cm/s), time-averaged average blood flow velocity (TAV, cm/s), Doppler perfusion index was calculated using the formula: V vol SPA / V vol SPA + V vol BB), the stagnation index was calculated using the formula: PPP/TAV. The results obtained. In patients with fatty liver disease, structural and hemodynamic shifts in the portal blood flow system are recorded: an increase in the diameter of the portal and inferior vena cava, a larger cross-sectional area, a low time-averaged maximum blood flow velocity and time-averaged average blood flow velocity, an increase in the stagnation index for these vessels, which reflects the process of remodeling the liver as a target organ in fatty liver disease and its vascular bed, forming a “stagnant liver”. Patients have lower values of the time-averaged average blood flow rate through the splenic vein, which indicates the initiation of collateral blood flow. Portal hemodynamics indicators correlate with metabolic parameters (anthropometric characteristics of patients (OT, BMI), steatotic indices (St index, FLI), but not with the liver fibrosis index (Fib 4). These hemodynamic features at the pre-cirrhotic stage of the disease, correlating with the severity of metabolic disorders, exacerbate structural changes in the liver and necessitate their correction in patients with fatty liver disease.