Hristo Abrashev

Chronic venous disease (CVD) is among the most common diseases in industrialized countries and has a significant socioeconomic impact. The diversity of clinical symptoms and manifestations of CVD pose major challenges in routine diagnosis and treatment. Despite the high prevalence and the huge number of venous surgical interventions performed every day, a substantial proportion of the etiopathogenesis remains unclear. There are several widely advocated and generally valid theories of “peri-capillary fibrin cuffs” and “white cell trapping hypothesis”, which consider the role of venous reflux/obstruction, inflammation, vascular remodeling, hemodynamic changes, genetic and social risk factors. There are several specific provoking factors for the development of venous reflux: incompetence of the valve system, inflammation of the vascular wall, and venous hypertension. Over the past few years, increasing scientific data has demonstrated the link between oxidative stress, endothelial dysfunction, and vascular inflammation. High levels of oxidants and persistent inflammation can cause cumulative changes in hemodynamics, resulting in permanent and irreversible damage to the microcirculation and endothelial cells. Production of reactive oxygen species and expression of inflammatory cytokines and adhesion molecules are involved in a vicious cycle of venous wall remodeling. The interaction of ROS, and in particular, the superoxide anion radical, with nitric oxide leads to a decrease in NO bioavailability, followed by the initiation of prolonged vasoconstriction and hypoxia and impairment of vascular tone. This review addresses the role of ED, oxidative, and hemodynamic stress in the CVD mediation. Based on predefined inclusion and exclusion criteria, we conducted a systematic review of published scientific articles using PubMed, PMC Europe, Scopus, WoS, MEDLINE, and Google Scholar databases in the interval from 24 April 2002 to 1 April 2025. The current review included studies (n = 197) scientific articles, including new reviews, updates, and grey literature, which were evaluated according to eligibility criteria. The selection process was performed using a standardized form according to PRISMA rules, the manual search of the databases, and a double-check to ensure transparent and complete reporting of reviews. Studies had to report quantitative assessments of the relationship between vascular endothelial dysfunction, inflammation, oxidative stress, and shear stress in a chronic venous disease.

Oxidative stress is a major source of ROS-mediated damage to macromolecules, tissues, and the whole body. It is an important marker in the severe picture of pathological conditions. The discovery of free radicals in biological systems gives a “start” to studying various pathological processes related to the development and progression of many diseases. From this moment on, the enrichment of knowledge about the participation of free radicals and free-radical processes in the pathogenesis of cardiovascular, neurodegenerative, and endocrine diseases, inflammatory conditions, and infections, including COVID-19, is increasing exponentially. Excessive inflammatory responses and abnormal reactive oxygen species (ROS) levels may disrupt mitochondrial dynamics, increasing the risk of cell damage. In addition, low serum albumin levels and changes in the normal physiological balance between reduced and oxidized albumin can be a serious prerequisite for impaired antioxidant capacity of the body, worsening the condition in patients. This review presents the interrelationship between oxidative stress, inflammation, and low albumin levels, which are hallmarks of COVID-19.

Traditional open surgery of the abdominal aorta and iliac segment is a surgical intervention with a relatively high risk and well-studied perioperative mortality. Over the last decade, there has been a constantly growing trend to reduce surgical trauma in the treatment of vascular diseases. The right choice of a vascular approach is crucial for the success of every open aorto-iliac vascular reconstruction. The mini-invasive vascular approaches offer significant advantages over classic surgery and are associated with better perioperative results.

SARS-CoV-2 infection, discovered and isolated in Wuhan City, Hubei Province, China, causes acute atypical respiratory symptoms and has led to profound changes in our lives. COVID-19 is characterized by a wide range of complications, which include pulmonary embolism, thromboembolism and arterial clot formation, arrhythmias, cardiomyopathy, multiorgan failure, and more. The disease has caused a worldwide pandemic, and despite various measures such as social distancing, various preventive strategies, and therapeutic approaches, and the creation of vaccines, the novel coronavirus infection (COVID-19) still hides many mysteries for the scientific community. Oxidative stress has been suggested to play an essential role in the pathogenesis of COVID-19, and determining free radical levels in patients with coronavirus infection may provide an insight into disease severity. The generation of abnormal levels of oxidants under a COVID-19-induced cytokine storm causes the irreversible oxidation of a wide range of macromolecules and subsequent damage to cells, tissues, and organs. Clinical studies have shown that oxidative stress initiates endothelial damage, which increases the risk of complications in COVID-19 and post-COVID-19 or long-COVID-19 cases. This review describes the role of oxidative stress and free radicals in the mediation of COVID-19-induced mitochondrial and endothelial dysfunction.

Since the beginning of the pandemic, a recommendation was made for the use of anticoagulants in high-risk hospitalized patients. This therapeutic approach has positive and negative effects regarding the outcome of the disease. Anticoagulant therapy prevents thromboembolic events, but it can also lead to spontaneous hematoma formation, or be accompanied by massive active bleeding. We present a 63-year-old COVID-19-positive female patient with a massive retroperitoneal hematoma and spontaneous left inferior epigastric artery injury.

Background and Objectives: Achenbach’s syndrome is usually a benign, self-limiting clinical condition presented with finger discoloration, pain, and edema. Etiology, pathogenesis, and incidence remain unknown due to the variety of clinical features and the diversity of disease states leading to digital ischemia. COVID-19 primarily affects microcirculation, causing endothelial damage and disseminated microthrombosis. Materials and Methods: We reviewed two cases of Caucasian women with Achenbach’s syndrome after COVID-19 infection recovery between April and May 2021. Results: Here are presented two extremely rare cases of paroxysmal finger hematoma in two female patients after COVID-19 infection recovery. Conclusions: The exact etiology and pathophysiology of Achenbach’s syndrome remain unclear. It is assumed that SARS-CoV-2 infection could be the triggering factor in the pathophysiological mechanism of paroxysmal finger hematoma. We highly recommend the implication of the synthetic prostacyclin receptor agonist (Iloprost) as a first-line conservative treatment in patients with Achenbach’s syndrome and COVID-19 infection recovery.

Among the groups of users of illicit substances, a high percentage are persons deprived of their liberty; at the same time, each social and age group is also affected, to one degree or another. The purpose of this study is to provide general data on the relationship between different psychostimulants, clinical and socio-demographic studies, and gender, both among the general population and in one of the most at-risk groups. This review identifies the use of illicit substances as gender-specific in the general population. A detailed study of the causal relationship between the use of illicit substances and gender was carried out. Electronic databases Academic Search Complete, PubMed, HealthCare, Web of Science, and Google Scholar were searched for relevant studies up to 2022 associated with drug abuse and mental and health disorders. The analysis indicated that the human population showed significant differences between the sex of the consumer as to the type of drug consumers, development of addiction, and relapse. We focus on the pathological changes caused by drug use, the personal and physiological individual traits that influence drug choice, and the extent of use in one of the most affected groups of individuals. The study may provide some guidance in developing gender-specific treatment and prevention, including response to some pharmacological and behavioral therapies. The review is intended for a wide audience of social workers, toxicologists, and pharmacologists.

Psychomotor stimulants are the most commonly used prohibited substances after cannabis. Globally, their use reaches epidemiological proportions and is one of the most common causes of death in many countries. The use of illicit drugs has negative effects on the cardiovascular system and is one of the causes of serious cardiovascular pathologies, ranging from abnormal heart rhythms to heart attacks and sudden cardiac death. The reactive oxygen species generation, toxic metabolites formation, and oxidative stress play a significant role in cocaine-induced cardiotoxicity. The aim of the present review is to assess acute and chronic cocaine toxicity by focusing on the published literature regarding oxidative stress levels. Hypothetically, this study can serve as a basis for developing a rapid and effective method for determining oxidative stress levels by monitoring changes in the redox status of patients with cocaine intoxication.