Detecting endothelial dysfunction by hemostasis testing in acute appendicitis

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INTRODUCTION

Endothelial dysfunction (ED) is defined as an imbalance in the synthesis of biologically active substances by endothelial cells, characterized by the overproduction of vasoconstrictive, prothrombotic, and proinflammatory agents [1]. In addition, there is evidence linking ED to the development of various thrombotic conditions [1]. Thus, ED is a crucial component of the inflammatory process, including in acute abdominal conditions [2]. Urgent surgical diseases of the abdominal organs remain highly prevalent [3]. The incidence of acute appendicitis and its complicated forms is also high [4]. Therefore, a deeper understanding of the pathogenetic aspects of acute inflammatory diseases of the abdominal organs, particularly the assessment of thrombotic readiness within the framework of ED, is critical. Identifying latent thrombotic potential, which is undetectable by routine coagulation testing, enables a more detailed study of ED and facilitates timely correction of its manifestations in patients with acute appendicitis (AA).

At present, acute abdominal condition remains highly prevalent [5]. One of the most common diseases in this category is AA [3, 4]. Endothelial injury is a key mechanism in the pathogenesis of acute inflammation of the vermiform appendix [1]. The main mediators of the inflammatory process simultaneously act as factors contributing to ED [2].

The development of the disease and its complications is determined by its etiology and pathogenesis. Currently, when discussing the mechanisms of AA, the obstruction factor is most frequently mentioned. Obstruction of the appendiceal lumen disrupts the passage of its contents, which is a key event in pathogenesis [5, 6]. Impaired outflow of secretions from the lumen of the vermiform appendix leads to infection. Microbial agents release bacterial toxins that form a focus of primary alteration [7]. Primary alteration begins when the pathogen interacts with the host organism. The boundaries of this focus correspond to the site of the pathogen’s initial impact. Secondary alteration develops later and is caused by the spread of virulence factors of pathogens (bacteria and viruses) and inflammation mediators produced in response to the pathogen from the focus of primary alteration into the surrounding perifocal tissues [7]. Thus, the secondary alteration zone forms around the primary one. Inflammation mediators produced within primary and secondary alteration sites promote the activation of lipoxygenase and cyclooxygenase enzymes. These enzymes initiate cascades that form leukotrienes and prostaglandins in the damaged area. Therefore, alteration is significant because it results in the formation of an inflammatory focus with the development of cellular and humoral immune factors [8].

The second stage of inflammation that is, exudation, is characterized by the development of vascular reactions and increased vascular wall permeability [5, 6]. These reactions include vasospasm, arterial and venous hyperemia, and local blood stasis [6]. Vasoconstriction induced by vasoactive substances is followed by arterial hyperemia, during which the appendix and its mesentery become hyperemic and local tissue temperature increases [7, 8]. In the microcirculatory bed, vasodilation develops and blood flow increases. As inflammation progresses, arterial hyperemia is replaced by venous hyperemia, during which regional blood flow slows down, cyanosis develops, and edema of the appendicular process and its mesentery (mesenteriolum) increases [8].

The development of venous hyperemia is promoted by hemoconcentration, which results from the escape of the fluid component of blood into local tissues under the influence of proinflammatory mediators, which is accompanied by microthrombus formation [8, 9]. Hageman factor (Factor XII) also plays a critical role, because it is activated during the alteration stage and participates in thrombogenesis. Microthrombosis of the vascular bed in the inflammatory focus is of great importance, as it results in blood flow retardation in the area of inflammation, accumulation of crucial inflammation mediators, and restriction of pathogen dissemination [5, 6].

Factor XII, which acts on the plasminogen–plasmin system, activates fibrinolysis at a certain stage of inflammation. This results in thrombus lysis and may promote the spread of the pathological process [10]. During venous hyperemia, the sequence of phases includes an initial pre-stasis state characterized by pendulum-like blood flow [8, 9]. This is followed by stasis, which is the final stage of vascular reactions, when blood circulation in the microvessels ceases. Stasis is manifested by the sludge phenomenon: erythrocytes lose their shape and form a homogeneous mass that obstructs the microvessels. These processes are largely mediated by the complement and kallikrein–kinin systems, prostaglandins, and other substances contributing to ED. Thus, stasis in the microvessels stimulates exudation [8, 11].

The role of vascular reactions in the inflammatory process includes confining it around the focus of alteration, concentrating inflammation mediators, and decreasing their systemic effects on the body. Owing to the organism’s ability to form an inflammatory response and isolate the focus of alteration, the systemic effects of proinflammatory and procoagulant mediators are minimized [9, 11].

In addition to fluid, exudation mainly involves immunocompetent cells. Leukocytes enter the focus of inflammation in three stages: first, under the influence of cytokines, they undergo margination and rolling toward the endothelium; then, they migrate through the endothelium and other vascular layers; and finally, the white cells move into the inflammatory site by chemotaxis [9, 11].

In complicated, diffuse inflammation, the limiting mechanisms of the process are largely lost [10, 12]. Overproduction of cytokines, complement components, and other proinflammatory mediators results in a pronounced systemic effect. As circulating blood volume decreases, cytokine and bacterial endo- and exotoxin concentrations in the body increase. In this case, the inflammatory process may become uncontrolled [13]. Large amounts of substances with proinflammatory and procoagulant effects enter the systemic circulation (Table 1).

 

Table 1. Substances with proinflammatory and procoagulant effects as endothelial dysfunction components

Target for toxins	Released or activated substance	Pathophysiological effect
Phagocytes	Interleukin-1 and interleukin-6 Tumor necrosis factor-α Interferons NO	Activation of macrophages PGI₂ release Vasodilation
Complement system	C3a C5a	Vasodilation Increased vascular permeability Activation of phagocytes
Platelets	PAF Thromboxane A2 PDGF	Platelet aggregation Thrombotic readiness
Hageman factor	Prekallikrein and kininogens Factor XI Fibrinolytic enzymes	Release of kallikrein and kinins Activation of coagulation and fibrinolysis
Neutrophils	Cationic proteins Kallikrein Lysosomal enzymes	Mast cell degranulation Activation of the complement system

 

However, the complex cytokine mechanism of the inflammatory response is regulated by the organism itself. Moreover, Hageman factor, which triggers the kallikrein–kinin system, can initiate fibrinolytic processes that simultaneously occur with clot formation, resulting in hypocoagulation. The mechanism underlying this type of hypocoagulation resembles the stages of disseminated intravascular coagulation, but is expressed to a much lesser degree [10, 14, 15]. Loss of immune system control over the effects of various cytokines is a life-threatening condition, in which the inflammatory response may be complicated by sepsis, disseminated intravascular coagulation, and other severe disorders [14, 15].

Thus, vascular endothelial damage occurs, and the endothelium releases large amounts of prothrombotic and proinflammatory mediators (Table 1). ED encompasses these processes [16].

ENDOTHELIAL DYSFUNCTION IN INFLAMMATION

In urgent surgical condition, ED develops as a result of acute inflammation. That is, the inflammation mediators involved in the pathogenesis of AA largely coincide with the main endothelial factors that play a crucial role in the development of ED [16].

The significant contribution of the endothelium to the regulation of the hemostatic system has been well-established [17]. Endothelial cells are capable of regulating the vascular–platelet and coagulation pathways of hemostasis, thereby performing thromboresistant and thrombogenic functions [17]. These functions are mediated by thrombo-regulators, which are substances released by endothelial cells that exert thrombotic and antithrombotic effects [17]. An equally critical role of endothelial factors is their influence on vascular wall permeability, vessel growth, and smooth muscle tone. These include arachidonic acid derivatives and plasminogen activator inhibitor [18]. Furthermore, endothelial factors can exert local and systemic effects [19].

The procoagulant activity of endothelial cells becomes pronounced when they are damaged or exposed to proinflammatory mediators, primarily tumor necrosis factor-α and interleukins. These mediators stimulate endothelial cells to release tissue thromboplastin, which is normally undetectable in the bloodstream, but appears following endothelial injury [17, 20].

During inflammation, the vascular endothelium produces plasminogen activator inhibitors. Their prothrombotic activity manifests under the influence of cytokines (tumor necrosis factor-α and interleukins), which increase the synthesis of these inhibitors and suppress fibrinolytic activity [17, 21].

Thromboxane A2 is one of the most active endothelial factors produced during endothelial injury. Its thrombogenic effect consists in increasing the concentration of Ca2+ ions in platelets and promoting their adhesion and aggregation. Furthermore, calcium metabolism is influenced by adenosine diphosphate, which is released from endothelial cells, leukocytes, and other cell types. Similar to thromboxane, adenosine diphosphate and calcium ion levels increase during acute inflammation and endothelial injury. In addition, thromboxane A2 can contribute to vasospasm. However, its effect is confined to the site of production because of its extremely short half-life [11, 22].

Notably, the thromboresistance of the vascular wall is one of the key aspects of ED. During the development of processes such as hypoxia or inflammation, endothelial thromboresistance markedly decreases [19]. Moreover, the procoagulant activity of endothelial cells may increase due to the presence of various endo- and exotoxins [22, 23].

Several studies have investigated ED in various pathological processes causing acute inflammation. Vlasova considered ED as a typical pathological process that underlies various diseases and serves as a universal mechanism of endogenization and generalization of the pathological process [19]. Loktionova et al. studied ED in different infectious diseases. They particularly focused on the role of infectious agents in the development of ED [23]. Sergienko et al. examined ED in experimental biliary peritonitis by measuring the levels of von Willebrand factor and endothelin-1 and the number of desquamated endothelial cells. The results demonstrated the influence of ED on the severity and outcome of the inflammatory process [24]. Zagorodskikh investigated endothelial injury in severe pancreatitis by determining the levels of endothelial growth factor and endothelial nitric oxide synthase gene expression and the number of circulating endothelial cells. The study revealed a correlation between the degree of endothelial damage and severity of pancreatitis [25]. Vlasov reported cellular damage caused by endotoxinemia accompanied by lipid peroxidation and phospholipase activation. A clinical and experimental study was conducted using lipid fractionation by chromatography followed by molecular analysis on a densitometer [26]. Saveliev determined ED in abdominal catastrophe but described differences in its pathogenesis. His monograph compared acute ED developing during peritonitis with chronic ED occurring in the postoperative period, referring to these changes as acute and chronic endotoxin aggression, respectively [27].

The above studies confirmed the association between endothelial injury and the development of acute inflammation. In AA, ED has been investigated only in isolated studies. Fikri et al. examined this phenomenon by assessing vascular endothelial growth factor expression; however, they found no significant differences between the groups [28]. Taşlıdere et al. studied the relationship between nitric oxide synthase activity and the course of AA and also found no significant differences [29].

These studies are extremely critical for understanding ED in acute inflammatory processes; however, almost all of the research methods used have major limitations. Methods such as determining the levels of endothelin-1 or vascular endothelial growth factor require considerable time to perform,¹ and time is a critical factor in conditions such as peritonitis and severe pancreatitis. Techniques for detecting endothelial nitric oxide synthase gene mutations and quantifying circulating endothelial cells are costly, difficult to access, and time-consuming.² Therefore, faster, more accessible, and reliable methods for assessing ED are warranted. Additionally, the method sought should be pathophysiologically justified.

Endothelial injury, including acute inflammation, may lead to a prothrombotic state. This is explained by the fact that various proinflammatory mediators are endothelial factors that determine the development of ED (Table 1) [31, 32]. That is, endothelial injury (along with other factors) defines the organism’s tendency toward thrombosis.

Momot et al. described the state of thrombotic readiness as a phenomenon characterized mainly by laboratory signs of accelerated blood coagulation in the absence of overt thrombus formation [33]. Blazhko et al. studied this condition using thromboelastometry in laboratory rats exposed to various physical factors. They examined the state of hemostasis after a 4-hour physical load. Rotational thromboelastometry revealed changes toward hypercoagulation, including a 25% decrease in clot formation time, a 9% increase in maximum clot firmness, and enhanced platelet aggregation [34].

Levshin et al. investigated methods for correcting the state of thrombotic readiness in patients with cardiovascular diseases by evaluating the proinflammatory and thrombogenic properties of the endothelium: the thrombin–antithrombin complex, platelet aggregation induced by adenosine diphosphate, D-dimer levels, and acute-phase proteins. During treatment with bemiparin, hemostatic parameters improved and inflammatory markers (C-reactive protein and fibrinogen) decreased [35].

The association between ED and hemostatic disorders has been demonstrated in several studies. Sizikov et al. examined the relationship between ED and hemostatic abnormalities by assessing nitric oxide metabolites, platelet aggregation, fibrinogen concentration, and von Willebrand factor levels [36]. They revealed a correlation between increased platelet aggregation and ED. Furthermore, Kotovshchikova et al. identified an association between ED and hypercoagulation in patients with myocardial infarction, before and during treatment with thrombovazim. In their study, indicators of ED (vascular endothelial growth factor and fibroblast growth factor) were compared with hemostatic parameters (coagulation test, antithrombin, and platelet aggregation induced by various agents). After therapy, significant decreases were observed in both groups of indicators, confirming a direct relationship between endothelial injury and coagulation disorders [37].

Gulyaeva et al. also demonstrated a correlation between ED and alterations in the blood coagulation system. In their study, increased endothelin-1 levels were associated with hypercoagulation, whereas decreased nitric oxide levels corresponded to a tendency toward hypocoagulation [38]. Considering these findings, the possibility of determining ED through the assessment of the hemostatic system cannot be excluded.

HEMOSTASIS SYSTEM ASSESSMENT

Several studies have examined hemostatic system parameters in patients with various forms of AA. Razin et al. investigated coagulation parameters in children with destructive forms of AA and demonstrated the low diagnostic value of classical tests, including activated partial thromboplastin time (APTT), international normalized ratio, prothrombin time (PT), and thrombin time [39].

Morandi et al. established that routine coagulation parameters (APTT and PT) enable the assessment of inflammation severity only in complicated cases of AA [40]. Contradictory results were reported by Li et al., who found that PT and APTT values significantly changed in patients with AA; however, PT correlated negatively with factor VII activity, whereas APTT showed a positive correlation. The authors also noted that fibrinogen levels could serve as a factor for excluding complicated AA [41].

In addition to classical methods for assessing the blood coagulation system, more advanced approaches exist [42]. However, because of their high cost, limited diagnostic value, or long turnaround time, immunological and molecular genetic methods for evaluating hemostasis are not practical in acute abdominal conditions. Integral methods for assessing the hemostasis and fibrinolysis systems, which can rapidly provide a comprehensive picture, are available. Among the most informative and modern techniques is rotational thromboelastometry, although the range of such tests is relatively broad and diverse [42].

At present, thromboelastographic studies make it possible to differentiate the nature of hypercoagulable and hypocoagulable states, thereby determining the appropriate treatment strategy. Their principle is based on measuring the elastic properties of the clot from its formation to the stage of fibrinolysis [43].

The parameters obtained from integral methods show changes across all components of the hemostasis and fibrinolysis systems. The functional range of thromboelastographic studies is quite broad, and the availability of additional reagent-based tests expands their diagnostic capabilities. Rotational thromboelastometry enables the identification of various causes of hypo- and hypercoagulable states, allowing for their differentiation [43]. Sheyranov et al. used thromboelastography to diagnose endogenous intoxication in patients with obstructive jaundice. In their study, thromboelastography revealed abnormalities undetectable by routine tests, which varied depending on the stage of jaundice. Signs of hypercoagulation were determined at the cytolytic stage, whereas signs of hypocoagulation emerged with cholangitis progression [44]. The study by Razin et al. also reported data obtained using the integral Thrombodynamics assay and demonstrated hypercoagulation in the early postoperative period in children with destructive AA [39]. Vlasov et al. employed thromboelastography to identify differences in the vascular–platelet and coagulation components of hemostasis and fibrinolysis in patients with mild and severe acute pancreatitis. Furthermore, they emphasized another distinctive advantage of integral methods that is, their high speed in obtaining results [45].

There are studies in which ED has been assessed using thromboelastometry. Bryushkov et al. found a positive correlation between ED factors and thromboelastogram changes in patients with phlebothrombosis [46]. Manoj Job et al. investigated ED using multiple methods, including thromboelastography [47]. That study revealed a positive relationship between disease severity, thrombomodulin levels, and von Willebrand factor concentration. In turn, Nava et al. demonstrated an association between selectin levels and thromboelastometry parameters [48].

The findings of these studies indicate the potential usefulness of rotational thromboelastometry in diagnosing latent hemostatic disorders caused by endothelial injury resulting from acute inflammation [49–51]. The degree of ED determined by thromboelastometry may reflect the severity of the acute inflammatory process in the abdominal cavity [52]. Therefore, assessing the extent of ED in AA appears suitable for predicting complications through hemostasis system analysis [52].

CONCLUSION

Accumulated theoretical and practical data over years of research on hypercoagulation indicate that the state of thrombotic readiness may develop in various forms of acute inflammation, particularly in AA. In such cases, ED develops under the influence of proinflammatory factors and serves as a process mediating the relationship between acute inflammation and hypercoagulation.

Owing to the body’s ability to localize the inflammatory process, it is almost impossible to detect the systemic effects of proinflammatory and procoagulant mediators using routine laboratory methods. However, the use of integral methods for assessing the blood coagulation system, such as rotational thromboelastometry, makes it possible to determine the heightened activity of the hemostatic system.

Further investigation of coagulation system parameters in acute abdominal condition appears promising. Of particular relevance is the establishment of correlations between the inflammatory response and findings of viscoelastometric hemostasis assessment methods, as latent hemostatic disorders identified in this way may be a criterion for evaluating the severity of the inflammatory process and course of the disease.

ADDITIONAL INFORMATION

Author contributions: I.A.O.: conceptualization, formal analysis, supervision, writing—review & editing; Zh.Zh.B.: methodology, validation, investigation, writing—original draft; K.T.B.: supervision, writing—review & editing; B.S.V.: visualization, writing—review & editing. All authors approved the version of the manuscript to be published and agree to be accountable for all aspects of the work, ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Acknowledgments: The authors express their gratitude to A.I. Chiryev, Associate Professor of the Department of Theoretical Surgery, Siberian State Medical University, for his support in manuscript preparation and review.

Funding sources: No funding.

Disclosure of interests: The authors have no relationships, activities, or interests for the last three years related to for-profit or not-for-profit third parties whose interests may be affected by the content of the article.

Statement of originality: No previously published material (text, images, or data) was used in this work.

Data availability statement: The editorial policy regarding data sharing does not apply to this work, as no new data was collected or created.

Generative AI: No generative artificial intelligence technologies were used to prepare this article.

Provenance and peer review: This paper was submitted unsolicited and reviewed following the standard procedure. The peer review process involved three external reviewers, a member of the editorial board, and the in-house scientific editor.

 

¹ Laboratory for the Diagnosis of Autoimmune Diseases. 2008–. Available at: https://autoimmun.ru/guide/sistema-komplementa-tsitokiny-i-biomarkery/kontsentratsiya-vegf-faktor-rosta-endoteliya-sosudov-v-syvorotke-krovi/. Accessed on: July 3, 2025.

² DNKOM Laboratory. 2025–. Available at: https://dnkom.ru/analizy-i-tseny/molekulyarno-geneticheskie-issledovaniya-bez-zaklyucheniya-genetika/endotelialnaya-sintaza-oksida-azota-nos3-c-786t/. Accessed on: July 3, 2025.

About the authors

Andrei O. Ivchenko

Siberian State Medical University

Author for correspondence.
Email: a.o.ivchenko@yandex.ru
ORCID iD: 0000-0002-3697-1816
SPIN-code: 3979-6802

MD, Dr. Sci. (Medicine), Assistant Professor, Head, Depart. of Faculty Surgery

Russian Federation, Tomsk

Zhan B. Zhamaliev

Siberian State Medical University

Email: zhan.zhamaliev@gmail.com
ORCID iD: 0009-0000-8937-5754

surgeon, Assistant Lecturer, Depart. of Faculty Surgery

Russian Federation, Tomsk

Tatyana B. Komkova

Siberian State Medical University

Email: tatyana.bkomkova@gmail.com
ORCID iD: 0000-0002-4164-6823
SPIN-code: 4365-8633

MD, Dr. Sci. (Medicine), Professor, Head, Surgical Diseases Depart. with the Course of Traumatology and Orthopedics

Russian Federation, Tomsk

Sergei V. Bystrov

Siberian State Medical University

Email: bystrovtomsk@yandex.ru
ORCID iD: 0000-0002-3425-0310
SPIN-code: 9878-4347

MD, Cand. Sci. (Medicine), Assistant Professor, Depart. of Faculty Surgery

Russian Federation, Tomsk

References

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