Objective. To study the results of pre-differentiated MSCs application in the treatment of femoral head necrosis in young patients. Methods. The developed high-tech approach included: exfusion of 50-70 ml of patient’s bone marrow 4 weeks prior to implantation; osteogenic differentiation and obtaining a biomedical cell product; surgical decompression and introduction of pre-differentiated MSCs in fibrin gel; postoperative rehabilitation. Surgeries were performed in 25 patients at stages I and II according to the ARCO classification. The average age of patients is 34 [29; 45], men - 20 (80%), women - 5 (20%). Theassessment scaleis avisual analogue scale (VAS), Harris scale, radiography, MRI. Results. Observation period was 41 [19; 59] month. Average Harris score before surgery was 76 [68.8; 79] points, after treatment - 90 [78.9; 92] points. In 15 (60%) cases an excellent results were obtained, in 5 (20%) - good, in 3 (12%) - satisfactory, in 2 (8%) - unsatisfactory (collapse progression). The level of pain syndrome was reduced from 40 [30; 50] to 10 [5; 25] points. There were no complications. Preservation of the femoral head sphericity and the width of the joint space, relief of bone marrow edema, reduction of the necrosis zone size and synovitis according to MRI data were found in 92% of cases. Conclusion. The treatment method of femoral head necrosis with the use of pre-differentiated MSCs in the absence of infectious triggers in the lesion focus made it possible to preserve 95 % of cultured cells in the cell product composition and to introduce it minimally invasively, avoiding the need for bone graft collection. The introduction of the cellular technologies in practice made it possible to obtain positive treatment results in 92% of cases due to an improvement clinical condition by the Harris scale and reduce of pain syndrome compared to the initial state; it did not lead to infectious, allergic or other complications within the 41 [19; 59] month follow-up. What this paper adds A method of cell therapy of femoral head necrosis affected young patients using pre-differentiated mesenchymal stem cells (MSCs) has been firstly developed. The use of a new method of treatment made it possible to obtain positive results and preserve the structures of the hip joints in 92% of cases due to the optimization of the osteoregeneration process has been demonstrated.

Objective. Development of a non-invasive assessing diagnostic and severity grading accuracy of portal hypertension in cirrhosis of the liver. Methods. To identify diagnostically significant indicators, a statistical analysis of the data of laboratory and instrumental diagnostics was carried out in 60 patients with liver cirrhosis. The followingbiochemical indicators weredetermined: general and biochemical blood tests, coagulogram, general urine analysis; the level of interleukin-6 (IL-6), matrix metalloproteinases 1 and 9 (MMP-1, MMP-9), tissue inhibitor of matrix metalloproteinase 1 (TIMP-1), hepatocyte growth factor (HGF); abdominal ultrasound examination, esophagogastroscopy. The index of the ratio of the number of blood platelets (N×10<sup>9</sup> / L) to the transverse size (D) of the spleen in millimeters (PSR - Platelet count to Spleen diameter Ratio) was calculated: PSR = NTr / D spleen. Results. The following indicators turned out to be diagnostically significant (predictive values based on ROC analysis are presented): blood levels of IL-6 (>19.9 pg/ml), MMP-1 (>8.06 ng/ml), cholesterol (≤4,5mmol/L), portal vein diameter (>13 mm), PSR (≤1.89). Diagnosticmethods for cirrhosis and portal hypertension was developed, based on a point assessment of a set of laboratory and instrumental criteria (AUC = 0.931; p <0.001). The method can be used in a complex of medical services aimed at diagnosis of portal hypertension severity in patients with cirrhosis of the liver, as well as medical prevention of life-threatening complications of the disease. Conclusion. The developed method makes it possible to identify patients with a «severe» form of portal hypertension, to recommend an unscheduled FEGDS with an endoscopic assessment of the risk of bleeding, and to carry out preventive and therapeutic procedures. If a low probability of a “severe” form of PH is identified, FEGDS should be refrained from if the patient has absolute or relative contraindications to the use of this diagnostic method. The method can be used in a complex of medical services aimed at diagnosing the severity of portal hypertension against the background of liver cirrhosis. What this paper adds For the first time, a method for diagnosis of portal hypertension in liver cirrhosis has been developed. It is based on a score assessment of a set of laboratory and instrumental criteria, including blood levels of interleukin-6, matrix metalloproteinase-1, cholesterol, platelet count, portal vein diameter and transverse size of the spleen. The method can be used in a complex of medical services aimed to estimate the severity of portal hypertension in cirrhosis of the liver, as well as medical prevention of life-threatening complications of the disease.

Objective. To determine the minimum inhibitory concentration of Ag nanoparticles in relation to clinical pathogenic strains of microorganisms. Methods. The minimum inhibitory concentration of Ag nanoparticles, obtained by metal vapor synthesis was studied on six strains of pathogenic bacteria, including representatives of gram-positive and gram-negative groups. The microbiological analyzer Vitek 2 Compact was used to identify each strain and to determine the antibiogram. The metal nanoparticles used in the study were synthesized by the method of metalvapor synthesis. Ag nanoparticles were studied by transmission electron microscopy(TEM) and X-ray photoelectron spectroscopy (XPS) methods. Determination of the minimum inhibitory concentration was performed by the method of serial dilution using sterile 96-well plates with using the tests of positive and negative control. The concentration of microorganisms was controlled by the turbidity standard. Results. All pathogenic strains of bacteria used in the study were characterized by pronounced polyantibiotic resistance, and the percentage of antibiotics against which the strain was resistant ranged from 12.5 to 93.3%. The minimum inhibitory concentration of silver nanoparticles ranged from 7.81 to 31.25 μg/ml, depending on the type of microorganism. Gram-positive microorganisms, in contrast to gram-negative ones, were characterized by lower values of the minimum inhibitory concentration. The data of transmission electron and X-ray photoelectron spectroscopy showed that the size of the studied nanoparticles is in the range of 2-15 nm. Conclusion. Silver nanoparticles (2-15 nm in size) have antimicrobial action against clinically significant, polyantibiotic-resistant strains of microorganisms. The minimum inhibitory concentration of silver nanoparticles, depending on the strain of the microorganism, varies from 7.81 to 31.25 μg/ml. Silver nanoparticles have an inhibitory impact on microorganisms and to a greater extent inhibit the growth of gram-positive versus gram-negative. The obtained materials based on silver nanoparticles represent an effective alternative to the currently used antibacterial drugs. What this paper adds The quantitative indices of the antibacterial action of silver nanoparticles have been firstly studied on pathogenic polyantibioticresistant strains of microorganisms The impact of the antibacterial resistance of bacteria does not affect the degree of antimicrobial action of these nanoparticles has been demonstrated Determination of the minimum inhibitory concentration of silver nanoparticles is considered to be a significant step in the development of a scientifically based method of using this class of substances in surgery

Objective. To substantiate the methods of surgical treatment in patients with postoperative ventral hernias and created intestinal fistulas based on the comparison of the outcomes of one-stage and two-stage operations. Methods. The analysis of patients (n=40) with postoperative ventral hernias and created intestinal fistulas imposed for therapeutic purposes or created as the treatment outcomes of uncreated fistulas has been performed. Jejunal fistulas were present in 7 patients (17.5%), ileal fistulas in 18 (45%), and colonic fistulas in 15 (37.5%) patients. The patients of group 1 (n=15, 37.5% ) underwent the two-stage operations. First, the fistula was closed with the access to the site of its location, and then after 3-6 months, the excision of hernia was performed. In patients of group 2 (n=25, 62.5%) fistula was simultaneously removed and hernia was excised. The «tension-free»techniquesinhernia orifice repair in those groups was performed. The outcomes were evaluated by the number of local and general complications in the period from 10 days to 6 months. Results. Wound complications after the first operation developed in 2 (13.3%) patients in the 1<sup>st</sup> group. There were no complications after the second stage of hernioplasty. In group 2, wound complications developed in 3 (12%) patients. There was no anastomotic failure in the groups. In the long terms, good results were obtained in 15 patients in group 1 and in 25 patients in group 2. The use of anterior prosthetic «tension-free»techniques of plastic surgery by the combined methods in one-stage allows obtaining results comparable to two-stage operations. Conclusion. In patients with hernias and intestinal fistulas, the method of treatment in one-stage or two-stages depends on the possibility of the gastrointestinal restoring patency from minimally invasive access in the site of the fistula location. What this paper adds For the first time, the indications for performing operations with postoperative ventral hernias and intestinal fistulas in one-stage and two-stage operations have been substantiated. Treatment option for patients with hernias and intestinal fistulas has been found to depend on the possibility of the gastrointestinal patency restoring from minimally invasive access in the site of the fistula location.

Objectives. To develop optimal postoperative wound care tactics for boys with hypospadias. Methods. The patients (128) with hypospadias aged from 11 months to 7 years were examined. The main group A consisted of 83 (64.8%) patients in whom we used a special bandage. It includes layer by layer of soft polyamide net two-sided onlay coated with soft silicone and adhesive properties, abundantly treated with an antimicrobial ointment containing an osmotic agent, sterile absorbent wipes with non-woven material, a circularly applied elastic bandage and an adhesive plaster with porous non-woven material. The dressing usually held up to 5 days. Group B included 45 (35.2%) patients with hypospadias, in whom we used a conventional sterile circular gauze bandage with antimicrobial ointment. The gauze bandage changed daily. For all clinical symptoms the groups were comparable in age. Postoperative wound healing had been monitored for 10 days after urethroplasty. The emphasis was made on such criteria as bleeding with hematoma formation, copious exudate excretion, penis skin hyperemia, «soft» and «dense» edema, drying crust (scab), skin sutures dehiscence, hypergranulation and necrosis. Results. In group A, problems with the skin flap and postoperative wound were detected only in 17 (20.5%) boys on the second or third day after removal of the special bandage. In the postoperative period, 41 (91.1%) patients in group B had «painful» skin changes in the area of the postoperative wound, which appeared almost the next day after surgery. Conclusion. The use of special bandage delays in time the contact of microbiota penis tissues compromised by surgery and the external environment, which, no doubt, improves the healing of skin grafts in the early postoperative period, and therefore reduces the number of urethroplasty complications. What this paper adds For the first time in patients with hypospadias, the process of postoperative wound healing was analyzed depending on the type of dressing. It was established that the use of a long-term bandage with a soft polyamide mesh doublesided pad with a silicone contact layer and adhesive properties compared to a traditional gauze bandage, which was changed daily, optimized the tactics of postoperative wound care in boys with hypospadias and minimized the number of urethroplasty complications.

Objective. To evaluate the effectiveness of platelet-rich plasma injections in the treatment of wounds in experimental animals with burns. Materials and methods. The experiment was carried out on 30 sexually mature male Wistar rats, which, after simulation of infected burn wound with boiling water and excision of necrotic tissue to pinpoint bleeding, hemostasis, on the second day, were divided into the main and control groups, depending on the chosen strategy of subsequent treatment. Wound defect of the animals in the control group (15 rats) was treated and bandages soaked in 0.02% decamethoxin solution were applied. Platelet-rich plasma was additionally injected into the wound area of the animals in the main group (15 rats) on the 1<sup>st</sup>, 3<sup>rd</sup>, 5<sup>th</sup> day after necrectomy. The remaining plasma was applied to the wound surface followed by closure with a polyvinyl chloride film and gauze bandage. Wound dressings were performed daily. The study involved a histological examination of the wound site and surrounding tissues the collection of which was carried out on the 1<sup>st</sup>, 3<sup>rd</sup>, 7<sup>th</sup>, 14<sup>th</sup> day after the removal of necrotic tissues. Results. In animals of the main group, the treatment of which involved the use of platelet-rich plasma, on the 3rd day after necrectomy in the wound area a decrease in the depth of injury that extended only of to subcutaneous tissue, a decrease in the activity of the inflammatory reaction in the tissues, followed by the proliferation of new epidermis and almost complete healing of wound defect up to 14 days were determined. For comparison, pathological changes in the tissues of the injured area of the animals in the control group were more pronounced with signs of muscle injury. In addition, during the entire observation period in this group of animals, an intense inflammatory reaction with low proliferative activity persisted. Conclusion. The effectiveness of platelet-rich plasma injections as an element of complex local treatment of burn wounds in rats has been experimentally confirmed. What this paper adds The expediency and effectiveness of platelet-rich plasma in the treatment of burns was histologically substantiated in the work on a specific experimental model of rats. In particular, its ability to positively influence the paranecrotic zone, reduce the intensity of inflammatory reaction in tissues, actively restore skin appendages, and stimulate the processes of proliferation and epithelization was established.

The failure of intestinal anastomotic suture is one of the urgent and dangerous problems in abdominal surgery. This problem not only complicates the course of the early postoperative period and increases financial costs, but it is also the main cause of deaths, the rate of which remains quite high with generalized peritonitis. The problem of the intestinal anastomotic leakage in the postoperative period forces researchers to develop various methods of preoperative preparation of patients, ways to strengthen the line of stitched ends of the intestine, new protocols for managing patients in the postoperative period. Despite the use of atraumatic and minimally invasive techniques as well as various stapling devices, and biopolymers of various compositions, the morbidity rate for ananastomotic leak remains quite high. The literature analysis demonstrates a tendency of preservation high rates of the suture failure of intestinal anastomosis. The actuality of this problem is especially clearly observed in case of emergency and urgent resection of the intestine against the background of acute intestinal obstruction, cancer intoxication and generalized peritonitis. The risk of anastomotic failure is believed to be caused by the age and general condition of a patient, the nature of the underlying disease, the presence of concomitant chronic diseases, the type of surgical operation, as well as the method and localization of the anastomosis being created. Despite the fact that there are a lot of sources devoted to the analysis of the causes of this problem, there is no consensus on the significance of risk factors and the effectiveness of the preventive methods used. In a number of publications there are contradictory data concerning the effectiveness of some preventive methods. Therefore, the solution of this problem requires new fundamental researches.

Literature searches were carried out on the Pubmed information platform and in the elibrary and Cyberleninka libraries by Keywords. Inclusion criteria are the following: availability of the full-text version of the original article, full compliance with the topic, publication period no more than 5 years. From 144 publications received, those completely duplicated and not meeting the inclusion criteria, were excluded. A total of 36 articles are included in the review. The epidemiology of biliary fistula after pancreatoduodenal resection, modern views on pathogenesis, classification, preventive measures and therapeutic and diagnostic tactics during its development are considered. In the postoperative period of pancreatoduodenal resection, biliary fistula is formed with a frequency of 1-24%. Non-modifiable risk factors include male gender, thin common bile duct, benign biliopancreatoduodenal pathology, and cancer with previous neoadjuvant therapy. Modifiable risk factors include obesity, hypoalbuminemia, obstructive jaundice, duration of hepaticojejunostomy, and prior endoscopic biliary drainage. Nowadays, effective and safe procedures are available in modern interventional radiology for the diagnosis and treatment of postoperative biliary fistula, which can be used as an alternative to endoscopic manipulations and revision interventions when the latter are associated with high risks of complications. Timely detection and treatment ensures the prevention of severe biliary fistula and repeated interventions and favorable prognosis, as well as saving medical and financial resources.

Objective. Optimization of treatment and diagnostic tactics for blunt injury of the pancreas, gall bladder and extrahepatic bile ducts. Methods. This current review was undertaken by Russian and foreign literature (2015-2020 yrs) search according to the following themes: pancreatic injury, traumatic pancreatitis, gall bladder injury, extrahepatic bile ducts injury, damage control surgery tactics, blunt abdominal trauma, therapeutic and diagnostic algorithm, conservative (non-operative) management, with subsequent exception from the request of experimental studies and cases of open trauma in the Internation scientific datebase PubMed, Cochrane Library, Scopus, Embase, ScienceDirect, Google Scholar Search, eLibrary. Multicenter studies, systematic reviews, meta-analyses, large case series, original articles, and randomized controlled trials were analyzed, indicating the levels of evidence and effectiveness of recommendations. An original algorithmfor thediagnosis and management is proposed, the concept of damage control is described, and indications for diagnostic methods, conservative treatment, and types of surgical, endovascular, and minimally invasive interventions are specified depending on the severity of organ injury according to the classification of the American Association of the Surgery of Trauma (AAST) (table). Results. The algorithmfor thediagnosis and management for combined blunt trauma of the pancreas, gallbladder, and extrahepatic bile ducts is standardized, and indications for minimally invasive and open interventions in this category of patients are clarified. Conclusion. Accurate knowledge of the algorithm for the diagnosis and management, indications for endovascular, minimally invasive techniques and open interventions, the choice of tactics based on the patient’s condition, the time of the injury, and possible complications can improve the results of treatment.

The case report of a patient with post-sternotomy mediastinitis is presented. A successful case of treatment of such a formidable complication after cardiac surgery was demonstrated. Success in the treatment of such patients depends on the complete cupping inflammatory process in the site of operation, as well as chest wall reconstruction. The positive clinical effect of vacuum-assisted dressings in the treatment of post-sternotomy mediastinitis is shown. The vertical rectus abdominis myocutaneous flap was used as a plastic material to cover a defect in the chest wall. The course of surgery and the result of treatment are described in details. To date, the surgical society has not developed a generally accepted tactic in the treatment of poststernotomy mediastinitis, both at the stage of arresting the infectious process, and in the process of reconstructive and restorative intervention. In practice, along with alloplastic materials, synthetic and metal implants are used. The autologous tissues include muscle flaps and the greater omentum. In thoracic surgery, the rectus abdominis can serve as an alternative to omentoplasty for extended chest wall defects.