The current problem of neonatal and pediatric surgery remains the tactics of surgical treatment and postoperative management of patients with perforated peritonitis. Mortality with perforation of the stomach and intestines in children in the newborn period reaches about 40-80 %. The combination of the syndrome of increased intra-abdominal pressure and multiple organ failure causes the extremely serious condition of patients. In this connection, new approaches to the surgical treatment of such patients are currently being actively developed. For this, new medical devices are tested in experimental practice, but the problem of such studies, first of all, lies in the lack of an adequate model of the pathological process. The aim of the work is to analyze the methods of experimental modeling of intestinal perforations described in the public domain. For this, a study was conducted of the most significant scientific publications of such databases as Google Scholar, PubMed, Scopus, eLIBRARY. The present work provides a detailed description of existing options for modeling perforations of various parts of the gastrointestinal tract (stomach, small intestine and colon), depending on the goals of the experiment. Several rather rare techniques based on the introduction of microorganisms are also presented. In addition, the article describes the method proposed by the authors for modeling perforation using laparoscopic access.

BACKGROUND. The development of new samples of local hemostatic agents is an intensively developing area of the modern industrial biotechnology due to a high need of clinical bases for such products. In addition to constant search for optimal substances used as a basis (collagen, cellulose and its derivatives, gelatin, etc.) for local hemostatic agents, methods for their comprehensive testing are also being developed. AIM OF THE STUDY. To evaluate the hemostatic activity of multicomponent polymer sponge implants using the coagulometer method developed by the authors in an in vitro experiment. MATERIAL AND METHODS. As research materials, new samples of multicomponent polymer sponge implants developed within the Laboratory of Experimental Surgery and Oncology of the Kursk State Medical University were used. The samples were based on marine collagen made from deep-sea squid in different ratios by weight with carboxymethylcellulose sodium salt (15/85, 25/75, 50/50). The hemostatic activity of these products was evaluated in the in vitro experiment using our method based on coagulometric measurement of blood clotting time of volunteer donors. Statistical processing of the data was carried out using methods of descriptive and variation statistics (Me [25; 75]). The validity of the difference was determined using the Mann–Whitney test (p ≤ 0,05). RESULTS. The blood clotting time in experimental group No. 2 turned out to be 2.12 s less than in the control group (the tested samples of hemostatic agents were not added). Statistically significant differences were found when comparing the values of coagulation time in experimental groups No. 3 (2.98 s less) and No. 4 (2.37 s less) with the values of the control group (No. 1). A decrease in the blood clotting time indirectly proves the effectiveness of the products used, due to the formation of the blood clot in a shorter period of time. This suggests that when the hemostatic agents are used in bleeding conditions, the products will reduce the time and volume of bleeding due to their hemostatic activity. CONCLUSION. Within the framework of the completed study, it was established that our method for assessing the hemostatic activity of local hemostatic agents, based on the evaluation of blood clotting time using electrocoagulometry, after grinding the tested samples, is easy to perform, accessible to most laboratories, and allows researchers to investigate the effectiveness of various forms of multicomponent polymer sponge implants. The development of multicomponent polymer sponge implants based on carboxymethylcellulose sodium salt and collagen seems to be a promising direction, since these products accelerate blood clotting time in the in vitro experiment.

Leakage of intestinal anastomoses remains an issue in view of the increasing number of patients who need reconstructive interventions in different parts of the gastrointestinal tract. Researchers around the world are actively looking for methods of strengthening intestinal anastomoses. The literature presents various approaches to sealing intestinal anastomoses in experimental animals using allografts, biological sealants, polymer film materials, etc. This article classifies and analyzes innovative methods of strengthening intestinal anastomoses to prevent their leakage. We also describe a concept of developing polymer membranes for interventions on hollow organs and our experience in this field of work and making of medical devices at the premises of a university research laboratory.

Introduction. Currently, immunological research is one of the priorities in the field of tuberculosis, since the effectiveness of treatment and, consequently, the outcome of the disease in most cases are determined by the immune and genetic characteristics of the macroorganism. Aim. To study the dynamics of cytokines (IL-6, IL-8, IL-4, IL-10, TNF-α, IFN-γ) in patients with pulmonary disseminated tuberculosis (DST) and fibrous-cavernous tuberculosis (FCT) after 2 months of specific chemotherapy. Materials and methods. The study group consisted of 100 patients with pulmonary tuberculosis (DST – 48 people, FCT – 52 people) aged 40 to 69 years who received specific chemotherapy in the intensive phase. The concentration of cytokines (IL-6, IL-8, IL-4, IL-10, TNF-α, IFN-γ) was determined at baseline and after 2 months of chemotherapy, as well as the cytokine balance (IL-6 + IL-8/IL-4 + IL-10) at baseline and after 2 weeks of chemotherapy. Results. After 2 months of chemotherapy, patients with DST showed a significant decrease in the level of IFN-γ, TNF-α, IL-6, IL-10, and the level of IL-8 tended to increase, however, this dynamic was not statistically significant; in patients with FCT, there was a significant decrease in the level of IFN-γ, IL-8, IL-6, as well as IL-4 – from 5.6 to 5.11 pg/ml, TNF-α – from 3.6 to 3.1 pg/ml, however, this trend was not statistically significant. The cytokine balance values tended to decrease: in patients with DST – from 7.7 to 7.48, and in patients with FCT – from 7.69 to 4.97. Conclusion. The cytokine system plays an important role in the regulation of inflammatory processes in patients with DST and FCT of lungs.

The interrelation between the TNFα gene polymorphism and the effectiveness of the intensive phase of chemotherapy in patients with pulmonary tuberculosis, as well as the formation of diameter of the sizes of destruction cavities was studied. It was revealed that the most adverse course of the disease and a high frequency of formation of destruction cavities are associated with the GG genotype of the TNFα gene.

Background. Currently, cases of damage to parenchymal organs for various reasons remain widespread. Most often, damage results from trauma and various surgical interventions. In modern surgical practice, a wide range of application hemostatic agents is increasingly used to stop bleeding from parenchymal organs. Hemostatic sponges are most widely used for these purposes. The advantage of this technique to stop bleeding is that the porous structure provides a high degree of adhesion to the wound surface without additional fixation and trauma to surrounding tissues.The aim of research was to comparatively study the body tissue response to implantation of two-component hemostatic sodium salt of carboxymethyl cellulose (Na-CMC) sponges in a chronic in vivo test.Materials and methods. The study materials included: a two-component sponge hemostatic Na-CMC-based agent (No. 1) (an experimental sample developed in KSMU, Russia), a collagen hemostatic sponge (No. 2) (JSC "Zelenaya Dubrava", Russia), "TachoComb" ( No. 3) (Takeda, Austria), Surgicel Fibrillar (No. 4) (Johnson Johnson, USA). Rabbits were subjected to a median laparotomy under inhaled anesthesia in the laboratory of experimental surgery and oncology at the Scientific Research Institute of Emergency Medicine, Federal State Budgetary Educational Institution of Higher Education KSMU, Ministry of Health of Russia; the animals were also simulated a superficial liver injury. This was followed by the application of tested samples of hemostatic products. In 1, 3, 7, 14 days after surgery, each animal underwent control-dynamic laparoscopy with the macroscopic assessment of the following parameters: the presence/absence and nature of pathological changes in the abdominal cavity (signs of inflammation, effusion, its nature and quantity), the severity of the adhesive process, the prevalence of adhesions, and the morphology of adhesions.Results. The lowest prevalence and severity of the adhesive process were observed under hemostatic Na-CMC sponge application. Statistically significant differences were obtained when comparing the prototype with all the study groups.Conclusion. After interventions two-component Na-CMC-based sponge application results in minimal manifestations of adhesions in the abdominal cavity of laboratory animals (1.3 times lower than in all comparison groups, p0.05). In all cases, the authors detected cord-like adhesions; their morphological substrate was a strand of the greater omentum. However, in spite of the presence of adhesions in the abdominal cavity, there were no clinically supported data on the development of adhesive intestinal obstruction. No signs of local or widespread peritonitis were detected in any of the animals.

Objective: to assess the immune status of systemic and local blood flow after femoral-popliteal bypass surgery in patients with and without restenosis. Materials and methods. The analysis of the treatment of 82 patients who underwent femoral-popliteal bypass surgery was carried out. Depending on the condition of the reconstruction zone after 12 months, the patients were divided into two groups: group I - 21 patients without restenosis, group II - 61 patients with the development of restenosis. The analysis of IgA, IgM, IgG, circulating immune complexes (CIC), interleukin (IL)-6, IL-1 in the systemic and local blood flow before and after surgery was performed. Results. In patients with the development of restenosis of the reconstruction zone, the level of IgA in the systemic and IgA, IgM in the local bloodstream was initially lower, the level of CIC, IL-1, IL-6 in the systemic and IgG, IL-1, IL-6 in the local bloodstream was higher, after surgery, the level of IgA in the local bloodstream was lower, higher - IgM in systemic and IL-6 in local blood flow in comparison with patients without restenosis. The correlation between the immune status and the development of restenosis was established: before surgery in the systemic circulation - IgA (r=-0.31, p<0.01), CIC (r=0.39, p<0.001), IL-6 (r=0.25, p<0.05), IL-1 (r=0.26, p<0.05), in the local bloodstream - IgA (r=-0.26, p<0.05), IgM (r=-0.30, p<0.01), IgG (r=0.26, p<0.05), IL-6 (r=0.30, p<0.01), IL-1 (r=0.29, p<0.01); after surgery in the systemic circulation - IgM (r=0.33, p<0.01), in the local - IgA (r=-0.24, p<0.05), IL-6 (r=0.40, p<0.001). The relationship between the degree of chronic arterial insufficiency (r=0.22, p<0.05), the ankle- brachial index after surgery (r=-0.27, p<0.05) with the development of restenosis was revealed. Conclusion. The interrelation of the immune status of the systemic and local blood flow before and after surgery and restenosis in the anastomosis zone after femur-popliteal bypass surgery has been shown. The study of the immune status will make it possible to develop an algorithm for restenosis prevention.

Various local hemostatics (based on collagen, gelatin, cellulose, etc.) are used to stop bleeding from parenchymal organs of the abdominal cavity. In the context of an acute in vivo experiment, this study aimed to comparatively assess the time and volume of bleeding from a trauma of abdominal cavity's parenchymal organs covered with a new collagen-based spongy hemostatics combined with Na-CMC. We used new multicomponent polymer sponge implants (MPSI) based on marine collagen and carboxymethyl cellulose sodium salt, Na-CMC; the components were mixed in the ratios of 15/85, 25/75, 50/50. Hemostatic activity of the samples was assessed by bleeding time and blood loss volume. For the experiments, rats underwent laparotomy and resection of the left lobe of liver (series 1) and lower pole of spleen (series 2). In both series of experiments, the controlled parameters (bleeding time and blood loss volume) were smallest in group 6, where the MPSI were 50/50 Na-CMC/collagen. The hypothesis of higher efficacy of composite local hemostatic agents (namely, made of Na-CMC and deep-sea squid collagen) in cases of trauma of the parenchymal organs was confirmed experimentally, and same experiment has also shown that collagen in the composition of MPSI boosts bleeding arrest (for liver injury, the smallest blood loss and hemorrhage control time was 41 s, for spleen injury — 57 s, respectively; p ≤ 0.05).

The results of a comparative study of the dynamics of serum hydroxyproline levels in laboratory animals after liver injury during laparoscopy and the cessation of bleeding from liver wounds on application of different local hemostatic agents are presented. The effects of these agents on hydroxyproline levels, which characterizes collagen metabolism, were evaluated. The study results demonstrated significant differences in all experimental groups.

Introduction: There is no adequate and easily reproducible model of complicated necrotizing enterocolitis (NEC) that allows to study its etiopathogenesis and test various surgical treatment options in an experiment. Objective: To devise a method for in vivo modeling of complicated NEC using laparoscopy. Materials and methods: Our study was conducted at the premises of the Laboratory of Experimental Surgery and Oncology (Scientific Research Institute of Experimental Medicine, Kursk State Medical University) in compliance with international ethical standards and guidelines for humane animal treatment. Fifteen immature male rabbits underwent laparoscopy under inhalation anesthesia and then subserosal injection of damaging solutions (33% H 2 O 2 , 10% CaCl 2 , 4% KCl, 70% C 2 H 5 OH, 10% CH 2 O) into the intestinal wall. In 24 hours, we performed laparotomy, assessed pathological changes visually, and resected the section of the intestinal tube at the injection site. Then we performed a single­layer end­to­end intestinal anastomosis. Histological samples were made from a biopsy specimen. Morphological assessment of the changes was performed. Results: The most pronounced macro­ and microscopic changes were found in the animals injected with hydrogen peroxide. We assessed changes in the abdominal cavity 24 hours since the start of modeling and observed a pattern of partial intestinal obstruction and serous peritonitis. The morphological pattern was characterized by acute circulatory disorder in the intestinal wall with ulcerative necrotic defects and perforations. Conclusions: Based on morphological manifestations we devised a method for modeling complicated NEC using laparoscopy. It is easily reproducible in an in vivo experiment, close to the clinical situation, and allows to simulate typical morphological changes during severe NEC.

ИССЛЕДОВАНИЕ РЕАКЦИИ ТКАНЕЙ НА ПРИМЕНЕНИЕ МЕСТНЫХ КРОВООСТАНАВЛИВАЮЩИХ СРЕДСТВ В ФОРМЕ ПОРОШКА IN VIVOЛипатов В

Introduction: In modern clinical practice, there is no common and effective hemostatic agent for solid organs of the abdomen. Local agents such as hemostatic sponges, membranes, powders seem promising. The main advantages of hemostatic powders include relatively high efficacy, portability, versatility, as well as simplicity and low cost of manufacturing. Objective: To study the hemostatic efficacy of hemostatic powders’ samples based on the sodium salt of carboxymethylcellulose (Na-CMC) in an acute in vivo experiment. Materials and methods: The study was based at Kursk State Medical University. Fifty male Wistar rats (weighing 220-239 g) were selected as test animals. They were evenly divided into 5 groups: ARISTA AH, Cutanplast Powder, and Na-CMC hemostatic powders with 3 different dynamic viscosities: low (50-200 cP), medium (400-800 cP) and high (1500-3000 cP). Under general inhalation anesthesia, median laparotomy was performed in Wistar rats, the middle lobe of the liver was removed into the wound, and then marginal tangential resection was performed. We applied hemostatic powders of each group to the resulting wound, and then estimated the bleeding time and the volume of blood loss. We used the Mann-Whitney test (P ≤ .05) to assess the statistical significance of differences between the study groups. Results: We recorded the minimum bleeding time and the smallest volume of blood loss for the samples based on the Na-CMC and found no statistically significant differences between the viscosities groups. Conclusions: With Na-CMC hemostatic powder the bleeding time and the volume of blood loss were reduced by 3.6 and 2.2 times, respectively, comparing to the control group. These results were considered statistically significant (P ≤ .05).

INTRODUCTION: Chitosan-based local hemostatic agents are most promising in terms of effective stoppage of bleeding, additional properties (for example, antibacterial effect) and stimulation of regeneration. New forms of them are being developed for different types of organ damage. AIM: To evaluate the hemostatic effect of samples of new chitosan-based local hemostatic agents on a liver resection model. MATERIALS AND METHODS: An in vivo experiment was performed on 60 white male rats of Wistar line of 200 g250 g mass. The animals were divided to 4 study groups of 15 animals, respectively, depending on the kind of hemostatic agent and additional introduction of an anticoagulant that enhanced bleeding. As study materials, hemostatic collagen sponge (control groups No. 1.1 and 1.2) and also samples of new chitosan-based hemostatic agents Сhitocol-Hemo (Evers, Russia) were used. The rats under general anesthesia underwent midline laparotomy followed by laparopexy by dissecting the falciform ligament of the liver and placement of a gauze turunda between the diaphragm and the left liver lobule with displacement of the latter into the wound. After this, a sterile gauze turunda of the known mass was placed under the left lateral lobe of the liver, and resection of this lobe was performed at 10 mm distance from the edge. The bleeding was stopped by application of the tested materials. The mass of blood loss (gravimetric parameters) and the time of bleeding were evaluated. The reliability of the differences was determined using nonparametric Mann-Whitney test. RESULTS: In animals that were not administered the anticoagulant before modeling of the liver trauma, statistically significant differences were found only in such parameters as increase in the sample mass after impregnation with blood, in percent. Here, the value of this parameter in the group with use of hemostatic collagen sponge (2262.9) was three times that in the group using hemostatic Сhitocol-Hemo (722.7) p = 0.000003. The differences between the groups with heparin therapy were of similar character (p = 000003). CONCLUSION: The hemostatic effect of the sample of Сhitocol-Hemo hemostatic agent was confirmed in an acute experiment on a model of liver injury in rats on the basis of measurement of the mass of blood lost, of blood absorbed by the sample, and also of bleeding time. This hemostatic effect is probably provided due to positive physicochemical characteristics (porous structure, stroma/pores ratio and composition of the agent.

Objective: To analyze the role of markers of the endothelial dysfunction in the vessels of the systemic and local blood flow before and after femoropopliteal bypass surgery (FPBS) in the development of restenosis at obliterating lesions of the femoropopliteal arterial segment (FPAS). Methods: The results of the examination and treatment of 82 patients with obliterating atherosclerosis who underwent FPBS were analyzed. Before and after surgery they underwent testing for serum homocysteine, oxidized low-density lipoprotein, soluble vascular cell adhesion molecule-1 (sVCAM-1), plasminogen activator inhibitor-1 (PAI-1), tissue-type plasminogen activator (t-PA), and annexin V in the systemic and local blood flow. Based on the condition of the reconstruction zone after 12 months, all patients were divided into two groups. Group 1 included patients without restenosis (n=21), and Group 2 – with restenosis (n=61). Results: Before surgery Group 2 patients showed significant differences in the severity of adhesive and hemostatic forms of endothelial dysfunction, as well as apoptosis in comparison with Group 1. It was found that before surgery, Group 2 patients had a significantly higher level of sVCAM-1 in the local bloodstream (by 37.5%, p=0.014), PAI-1 in the systemic and local bloodstream (by 15.6%, p=0.010, and by 16.4%, p=0.008 respectively) and annexin V in the systemic and local bloodstream (by 48.9%, p=0.012 and by 60.2%, p=0.002 respectively). After surgery Group 2 patients had significantly higher levels of PAI-1 in the systemic (by 18.9%, p=0.004) and local (by 11.1%, p=0.049) blood flow, and annexin V in the systemic circulation (by 28.4%, p=0.011) compared with Group 1. Thus increased levels of sVCAM-1 in the local bloodstream, PAI-1, and annexin V – in the systemic and local bloodstream before surgery were associated with postoperative development of restenosis, while higher values of PAI-1 in the systemic and local bloodstream and annexin V in the systemic circulation after surgery were related to subsequent restenosis development. Conclusion: The results of the study indicate impairment of the adhesive and hemostatic function of the endothelium, and increased level of apoptosis in the blood vessels of systemic and local blood flow in patients with restenosis, which can be used to develop personalized approach to management of this disorder and improve the results of revascularization interventions on FPAS. Keywords: Obliterating atherosclerosis of the lower extremities, femoropopliteal bypass surgery, functional activity of the endothelium, restenosis.

Neonatal necrotizing enterocolitis (NEC) is a multifactorial disease of unspecified etiology. The lack of data on etiological factors and the complexity of pathogenetic mechanisms determine the complexity of NEC modeling. The authors involved in the study of the pathogenesis of NEC and the development of current treatments seek to model in the experiment the conditions that occur in clinical practice. Thus, this study aimed to analyze the options for the experimental modeling of neonatal NECs described in the public domain. Thus, more than 50 relevant scientific publications in databases such as Google Scholar, PubMed, Scopus (publishers Elsevier), and eLibrary (from 2000 to 2022) were reviewed. This paper describes the most current methods of modeling NEC, including in vitro (using cells and cell cultures), in vivo (in laboratory animals such as mice, rats, rabbits, and pigs), and ex vivo (using cadaver material) experiments.

Currently, purulent-inflammatory diseases of the abdominal organs are the prevalent causes of complications and mortality. Treatment of these diseases complicated by peritonitis is one of the urgent problems in modern clinical medicine. Experiment is important for testing new treatment methods. This article provides a systematic analysis of the current in vivo models of the purulent peritonitis, which are used to test the options for surgical treatment and combinations of antibacterial drugs. We describe the most common models as well as rare simulations of specific peritonitis. It should be noted that despite the wide use of minimally invasive techniques, the literature has few reports on simulation of peritonitis through the laparoscopic approach.

Currently, the effective stop of parenchymal bleeding that has developed for various reasons: trauma, planned and emergency surgical interventions, is a serious challenge for modern clinical surgery. Today, in the arsenal of doctors there are a large number of hemostatic agents that affect the coagulation process, however, local hemostatics attract much attention, since they have a significant advantage - the absence of a systemic effect on the blood coagulation system. The objective: in a comparative aspect, to study the effectiveness of two-component sponge hemostatic agents in the model of marginal liver resection in vivo. Materials and methods. In a comparative aspect, we studied the hemostatic activity of samples of local application hemostatic agents "TachoComb" (No. 1), prototypes of two-layer spongy hemostatic agents based on sodium salt of carboxymethylcellulose of various viscosities (No. 2), Surgicel Fibrillar. Rats under inhalation anesthesia underwent a median laparotomy, modeled marginal resection of the left lobe of the liver. Bleeding was stopped by applying the compared samples, while recording the amount of blood loss and bleeding time. In order to assess the statistical significance of differences between study groups, the Mann-Whitney test (p≤0.05) was used. Results. The minimum time to stop bleeding was noted in group No. 2. When comparing the volume of blood loss, no statistically significant differences were found. Conclusion. The use of samples of two-layer sponge hemostatic agents developed and tested in the experiment based on the sodium salt of carboxymethyl cellulose of various viscosities in stopping parenchymal bleeding in laboratory animals is not inferior to the currently used local hemostatics in terms of blood loss and statistically significantly accelerates the process of stopping bleeding.

Objective – Our study aimed at evaluating changes in liver tissues after simulated injury and use of novel hemostatic agents (containing tranexamic acid) in the course of in vivo experiment. Material and Methods – The following hemostatic agents were studies: TachoComb collagen plate (Group 1); samples of novel local hemostatic agents based on sodium carboxymethyl cellulose (CMC), Na-CMC (Group 2); Na-CMC + tranexamic acid (Group 3). We performed the study on 30 rabbits with simulated liver laceration via laparoscopy, and were stopping bleeding by means of the above-mentioned methods. Then, on liver tissue micrographs, we were measuring capsule thickness (μm), sizes of hepatocytes and their nuclei (px), number of binuclear hepatocytes. We were also calculating nuclear-cytoplasmic ratio (NCR) of hepatocytes, as well as identifying qualitative and quantitative capsule composition in tested samples. Results – In the collagen plate group, the capsule width was 3.2-fold and 3.6-fold of this parameter in samples from Groups 2 and 3. Indirectly, this finding implied more severe inflammatory and regenerative processes aimed at limiting injury area, and was confirmed by statistically significant differences in the cellular composition of the capsule surrounding tested samples (fibroblastic cells predominated in Groups 2 and 3, and there were fewer of them in Group 1). The highest cell index (CI) value was detected in Group 3. Conclusion – A significant boundary zone separating tested materials from the liver parenchyma was also observed due to connective tissue growth as part of inflammatory response.

Purpose of the study. Assessment of the effect of hemostatic materials on concentration of calcium of blood.Materials and methods. The following groups of local hemostatic materials were studied: collagen plate (No. 2), hemostatic sponge from medical gelatin (No. 3), oxidized cellulose material (No. 4), experimental samples of hemostatic sponge developed by the team of authors, based on the sodium salt of carboxymethylcellulose with various modifications (groups No. 5-8). In the control group (No. 1), only blood of volunteer donors was used, without introducing the test materials. Evaluation of the effect of hemostatic materials on blood calcium concentration was carried out according to the described method: «Method for comparative investigation of the effectiveness of local hemostatic agents in an in vitro experiment» Russian patent No. 2709 517. According to the results of the study, median, 25 and 75 percentiles were calculated. The validity of differences between groups was determined using the non-parametric Mann-Whitney test (p<0.05).Results. In groups using various materials, such as group No. 2 (Tachocomb) by 0.24 mmol/L and group № 4 (Surgicel Fibrillar) by 0.7 mmol/L, the serum calcium level was statistically significantly lower than the control group. Significant differences of calcium level values after blood immersion of volunteer donor samples based on cellulose derivatives were revealed, namely in group No. 5 (Na-CMC + Tranexamic acid pressed) value exceeds that in group No. 4 by 0.58 mmol/l. In other cases, comparisons of calcium concentration values in groups using experimental samples (not introduced into clinical practice) with material widely used in abdominal surgery (group No. 4) were found to be greater: in group No. 6 (Na-CMC + Tranexamic acid unsaturated) by 0.61 mmol/l, in group No. 7 (Na-CMC pressed) by 0.75 mmol/l, in group No. 8 (Na-CMC unsaturated) by 0.5 mmol/l.Conclusion. It should be noted that although there are no significant differences in the groups using experimental samples of local hemostatic agents and the control group, the calcium levels in groups No. 5-6 are close to those in the groups using widely known materials such as Tachocomb (No. 2) and Gelita-Spon Standart (No. 3). Also, among the samples developed by the authors, the greatest effectiveness was identified in group No. 8 (Na-CMC, unpressed), in which the serum calcium levels (2.14 mmol/L) are lower than in groups No. 5-7.