Aim. The study aim was to assess the negative dynamics of the hepatic artery resistive index as a reliable predictor of early thrombosis in liver transplant recipients from a postmortem donor, to determine risk factors and to identify a group of patients with an increased risk of this complication.
Material and methods. From July 2018 to August 2021, 92 orthotopic liver transplants from a deceased donor were performed at the Surgical Clinic of the City Clinical Hospital n.a. S.P. Botkin. All liver grafts were taken from donors with brain death. Control Doppler ultrasound examination of hepatic blood flow in all patients was performed on days 1, 3, 5, 7, if necessary, daily. The hepatic arteries resistive index was considered normal at values from 0.55-0.79, high at 0.8-0.89, extremely high above 0.9. Depending on the resistive index value on the 1st postoperative day and its further dynamics, we divided the patients into 3 groups. In each group, we analyzed the incidence of hepatic artery thrombosis and assessed the impact of various risk factors on the resistive index elevation on the 1st day after surgery and on its growth during dynamic observation in the early postoperative period.
Results. Of 92 liver transplants, in three cases, we recorded hepatic artery thrombosis (3.2%), which was not associated with technical difficulties of arterial reconstruction. No mortality was recorded in all three cases. In patients with a normal or high resistive index on the 1st day, without its increase during dynamic observation, the incidence of arterial thrombosis was 0%. In patients with a normal or high resistive index on the 1st day, and its increase during dynamic observation, as well as in patients with an extremely high resistive index on the 1st day, the incidence of arterial thrombosis was 18.1% and 11.1%, respectively. The risk factors of thrombosis were the age of the recipient over 50 years old in an extremely high resistive index on the 1st postoperative day (p=0.024), and the age of the donor over 50 years old in the growth of the resistive index during follow-up (p=0.04).
Conclusion. The lack of positive dynamics in the hepatic artery resistive index reduction may be an additional predictor of arterial thrombosis after liver transplantation. This fact makes it possible to identify a high-risk group of arterial thrombosis, to take additional preventive measures in these patients and to improve the immediate results of treatment in this group of patients.

Background. The novel coronavirus infection (COVID-19) pandemic has had a significant impact on all areas of health care system, including organ donation and transplantation. Despite this, there were no large Russian studies of COVID-19 course and outcomes in liver transplant recipients.
The study purpose was to determine prevalence, clinical course, severity, outcomes of COVID-19, as well as to assess the safety and efficiency of vaccination for disease prevention in liver transplant recipients.
Material and methods. 260 recipients (71% of all patients at risk of COVID-19 disease) who underwent liver transplantation at State Research Center – Burnasyan Federal Medical Biophysical Center from May 2010 to September 2021 were included in a single-center cross-sectional study. Data collection was performed during a telephone or face-to-face interview from September 6, 2021 to September 20, 2021. If patients were hospitalized with COVID-19, we also analyzed the results of laboratory and instrumental tests, other medical documentation.
Results. By mid-September 2021, the incidence of COVID-19 after liver transplantation was 31% (75 cases in 260 recipients). Asymptomatic course was observed in 11 (15%) patients. Hospitalization was required in 18 (28%) cases. In one case, COVID-19 infection was the cause of death. Mortality and death rate in the study cohort were 1% (1/75) and 0.4% (1/260), respectively. Risk factors that statistically significantly increased the likelihood of infection with SARS-CoV-2 were contact with the patient (OR: 12.9; 95% CI: 6.6 - 25.0) and non-compliance with non-specific prophylaxis measures (OR: 2.0; 95 % CI: 1.1 - 3.7). The recipient's age of 60 years or more significantly increased the risk of severe infection (OR 5.0; 95% CI: 1.3 - 18.7). None of the immunosuppressive therapy regimens significantly increased the risk of severe disease. Tacrolimus monotherapy or in combination with other drugs reduced the risk of severe COVID-19 (OR: 0.2; 95% CI: 0.1 - 0.95). Vaccination against SARS-CoV-2, which was performed in 42 (17%) recipients, did not cause serious adverse events and significantly reduced the risk of COVID-19 disease (OR: 7.2; 95% CI: 1.7 - 31.3). The detection rate of specific IgG antibodies to SARS-CoV-2 was 94% in recipients who had undergone the disease and 45% among those vaccinated (p<0.001). The achieved level of herd immunity against COVID-19 in the analyzed cohort was 48%.
Conclusion. Adult liver transplant recipients are not at an excessive risk of COVID-19 disease. Compliance with preventive measures and vaccination can significantly reduce the risks of infection and severe infection. There is no objective evidence that immunosuppressive therapy increases the risk of severe COVID-19 in liver transplant recipients. In the context of the ongoing COVID-19 pandemic, tacrolimus monotherapy may be considered as a safe regimen of maintenance immunosuppression.

Background. Reconstructive surgery for iatrogenic injuries of the bile ducts involves the formation of a biliodigestive anastomosis. The development of anastomotic stricture is the most severe complication of this operation.
Aim of the study. To evaluate the immediate and long-term results of treatment and follow-up of patients with iatrogenic injuries of the bile ducts who underwent reconstructive surgery on the bile ducts with additional creation of gastroenteroanastomosis.
Material and methods. The study included 26 patients operated on according to the original method in the period 2010-2018.
Results. In the study group, complications in the early postoperative period developed in 3 (11.5%) patients. Endoscopic interventions using the formed gastroenteroanastomosis in the long-term period were performed in 7 patients. The results of treatment were followed in 25 (96%) patients. The median follow-up period was 90 months [81.5;110] (42-129).
Conclusion. The use of the proposed original technique of reconstructive surgery has demonstrated its effectiveness and safety, with the possibility of dynamic endoscopic control and, if necessary, the treatment of postoperative complications such as cholelithiasis and biliodigestive anastomosis strictures.

Background. The problem of pathologically increased permeability of the intestinal wall is actualized with the accumulation of information about the correlation of this phenomenon with complications of an inflammatory nature and multiple organ failure in critical conditions, including acute poisoning.
Aim of study. To assess the effect of the program of enteral correction of homeostasis disorders on intestinal permeability in acute poisoning.
Material and methods. 40 patients (67.5% of women and 32.5% of men) admitted at the Intensive Care Unit as part of the Scientific Department of Acute Poisonings and Somatopsychiatric Disorders of the N.V. Sklifosovsky Research Institute for Emergency Medicine were examined, 20 of them (group I) with severe acute oral poisoning with corrosive substances: acetic acid 35.6% and alkali (sodium hydroxide) 64.4 %, as well as 20 patients (group II) with severe acute oral poisoning with psychopharmacological agents. Both groups were divided into two subgroups: I-a and II-a – (10 patients in each), in whom an enteral correction program was used in addition to the standard treatment, and I-b and II-b comparison groups (10 patients in each each) who received only standard therapy.
Results. It was found that in all observed patients with severe acute oral poisoning with corrosive substances, as well as psychopharmacological agents, the ratio of lactulose / mannitol concentration in urine as an indicator of intestinal permeability was increased before the start of treatment in relation to its reference value of 3.8-4.9 times.
After 5 days, in patients who received the enteral correction program, the lactulose/mannitol ratio decreased by 15.4% in cases of poisoning with corrosive substances, and by 19.8% in cases of poisoning with psychopharmacological agents. At the same time, in patients with poisoning with corrosive substances, who received standard treatment, this parameter decreased by only 1%. Attention was drawn to the fact that in patients with psychopharmacological agents poisoning who received standard therapy, the intestinal permeability index after 5 days did not decrease, but continued to increase and exceeded the initial value by 11.4%.
Conclusion. With the help of the enteral correction program, it is possible to reduce the permeability of the intestinal wall in acute poisoning with corrosive substances and psychopharmacological agents.

Relevance. The United States of America is currently one of the world leaders in organ donation and transplantation. In 2020, donor activity in the United States amounted to 38.0 per 1 million of the population, even exceeding the number in Spain 37.9 per 1 million of the population. In this context, the study of the American system of organ donation and transplantation in order to develop an accessible format for interaction with the population to strategically stimulate the potential of organ donation is of particular interest.
Aim. To study the organ donation and transplantation system in Nebraska, United States of America, to develop an accessible format for interaction with the population to strategically stimulate the potential of organ donation in the Republic of Tatarstan.
Material and methods. We presented the experience of the international internship «Organ donation and transplant management » at the University of Nebraska Medical Center (USA). We described the peculiarities of the functioning of the American transplant programs, the advantages in the matter of organizing organ and tissue donation.
Results. In the USA, with a population of 327 million people, today more than 165 million (51%) people are registered as potential donors. At the end of 2018, in the United States 36,428 transplants of various organs and tissues, or 111.4 per 1 million population, were performed. At the same time, the number of deceased donors was 10,700, the number of living donors – 6,800. At the University of Nebraska Medical Center during the same period, 301 transplants (158.4 per million population) were performed from 68 deceased and 40 living donors. The analysis of the American system of organ donation and transplantation with effective interaction of the state, commercial and non-profit sectors, independent of the National Health System, made it possible to organize in 2020 the first social project in the Republic of Tatarstan on organ donation – "Donate Life Russia".
Conclusion. The experience of the Republic of Tatarstan in attracting the non-profit sector to solving problems in the development of the transplant programs, following the example of the United States of America, has high potential in the Russian Federation.

The actual problem of treatment of patients with limbal cell stem deficiency is reviewed. We summarized practical experience in various fields of medicine, aimed at tissue reconstruction using cells of the buccal mucosa. In ophthalmology, an effective method has long been searched to treat patients with the limbal stem cell deficiency causing an intense opacification and vascularization of the cornea and followed by a significant decrease in visual acuity. Recent studies have shown that the transplantation of epithelial cells of oral mucosa can significantly improve the treatment of patients with this disease. Although the mechanisms of oral mucosa epithelial cells' action are still insufficiently studied, the existing positive experience of oral mucosa using for tissue repair has great interest to practitioners, giving potential possibilities of its use, therapeutic effectiveness and ease of obtaining. A brief review of the literature presents the description of the morphological features of the. buccal mucosa and the analysis of published data about the use of buccal epithelium in various branches of medicine and in ophthalmology, in particular.

The main method of surgical treatment of patients with post-traumatic disorders of bone regeneration is the use of bone grafting. Until now, the optimal plastic material has been a bone autograft, which use involves additional trauma to the patient. Alternative materials that are used for grafting have only an osteoconductive effect, of varying effectiveness. To optimize the properties of plastic materials, giving them an osteostimulating effect, they can be used in combination with biologically active substances. A source of biologically active substances can be platelet-rich plasma, platelet lysate and red bone marrow. This literature review includes a description of three main methods to stimulate osteogenesis. The first part examines the mechanism of action of platelet-rich plasma, indications and contraindications for its use, describes the results of treatment when platelet-rich plasma is used to stimulate osteogenesis. Platelet-rich plasma is a product of a human native blood obtained by centrifugation. The output is a high concentration of platelets in a small volume of plasma, which contain growth factors and cytokines that have a direct effect on the regeneration process. Local platelet-rich plasma therapy is performed to stimulate osteogenesis. Autologous platelet-rich plasma with growth factors contained in α-granules of platelets is injected into an allogeneic graft or into a fracture zone. The aim of this article is to summarize the results of treatment using platelet-rich plasma to improve bone regenerative potential in orthopaedics.

On June 20, 1962, at the N.V. Sklifosovsky Research Institute for Emergency Medicine in Moscow, V.P. Demikhov, a biologist, physiologist, and experimental surgeon transplanted a second, additional heart together with the lung through the left thoracotomy access in the fourth intercostal space into the place of the removed two upper lobes of the left lung into the chest to the dog named Grishka. The second heart was implanted in such a way that arterial blood circulated in it and in the transplanted lung. The donor and recipient were selected according to the blood group match. The immediate postoperative period was uneventful. On day 4, the dog became active. On day 12, the sutures were removed from the skin wound. On day 15, antibiotics (penicillin and streptomycin) were discontinued. During the daily examination, general condition and physical activity were noted, rectal temperature, respiratory rate and contractions of one's own and transplanted heart were measured; electrocardiograms were taken from both hearts. On day 13, Grishka gnawed through the electrode, which helped taking the electrocardiograms from the transplanted heart during the first 2 weeks. As a result, in place of the electrode remaining in the chest, the animal developed a fistula with purulent discharge. For this reason, as well as for coughing and wheezing in the lungs on the left, Grishka was periodically administered antibiotics. After the operation and before the withdrawal from the experiment, the dog was injected with heparin. No other pharmaceuticals were given. The dog led an active lifestyle, ate well, and displayed interest in female dogs. The second heart ceased beating 142 days after the operation, on November 8, 1962. Resuscitation measures were unsuccessful. At autopsy, in the right atrial auricle of the transplanted heart, diffuse transmural hemorrhage and a thrombus from the endocardium were revealed, which blocked the blood flow to the heart. The lower lobe of Grishka's lung was in a state of hepatization. Signs of edema and inflammation were observed in the transplanted lung. There were no blood clots at the sites of vascular anastomoses. There were no visual signs of rejection. The results of histological studies are not known. This article for the first time introduced into scientific circulation an operation protocol, a diary of postoperative management and an autopsy protocol for an animal that had lived with a second, additional heart and a transplanted lung without immunosuppression for 142 days, which has been a unique observation in world transplantology. Despite the long-term survival of the animal, nursing the recipient dog in the postoperative period did not meet the complexity of the operation performed, which allows us to conclude that it was impossible at that time to implement the results obtained in the experiment into clinical heart transplantation in humans.