[Liver transplantation program at the Burnasyan Federal Biophysical Center: experience in 500 procedures]. / Programma transplantatsii pecheni v Federal'nom meditsinskom biofizicheskom tsentre im. A.I. Burnazyana: opyt 500 operatsii.

OBJECTIVE: To analyze the features and outcomes of 500 liver transplantations in adults over a 12-year period. MATERIALS AND METHODS: The study included data on 500 liver transplantations between May 2010 and April 2023. We analyzed 483 adults who underwent transplantation and 438 candidates for this procedure. All data were obtained from local liver transplantation registry. Clinical outcomes were recorded as of June 1, 2023. Statistical analysis was performed using the Statistica 12 (StatSoft Inc., USA) and Jamovi version 2.3.21.0 software (Jamovi project). RESULTS: Among 438 patients in the waiting list between January 2012 and May 2023, liver transplantation was performed in 198 (45%) cases including 27 (6%) transplantations from living-related donors and 37 (8%) procedures in other centers. There were 109 (25%) deaths. The 1- and 3-year survival rates were 81% (95% CI 76-85%) and 50% (95% CI 42-59%), respectively. Organs from deceased donors (n=134, 27%) and living-related donors (n=366, 73%) were used for transplantations. Redo transplantations were necessary in 21 (4%) cases. The median age of recipients was 45 years (range 18-72), median MELD-Na score - 16 (range 6-43). The most common indications for transplantation were viral cirrhosis (37%), cholestatic liver disease (16%), and hepatocellular carcinoma (14%). Monotherapy with calcineurin inhibitors was performed in 39% of cases, combination of calcineurin inhibitors and glucocorticoids, antimetabolites or mTOR inhibitors - 52%, three-component schemes - 8% of cases. Annual, 5- and 7-year survival rates of recipients after primary transplantation were 87% (95% CI: 84-90%), 79% (95% CI: 75-83%) and 75% (95% CI: 70-80%), respectively. In case of liver transplantation from living-related donors, these values were 89% (95% CI: 86-92%), 84% (95% CI: 80-88%) and 80% (95% CI: 75-85%), after transplantation from deceased donors - 81% (95% CI: 74-88%), 66% (95% CI: 57-76%) and 58% (95% CI: 45-72%), respectively. CONCLUSION: Liver transplantation is highly effective for patients with diffuse and focal liver diseases. Living donors not only significantly improve availability of this technology, but also provide substantial advantages in outcomes compared to liver transplantation from deceased donors, reducing the likelihood of recipient mortality by 10% after one post-transplantation year and by more than 20% after five years.

[Vascular reconstruction and transplantation technologies in liver surgery (part II)]. / Sosudistye rekonstruktsii i transplantatsionnye tekhnologii v khirurgii pecheni (chast' II).

OBJECTIVE: To systematize tactical and technical aspects of liver resections with reconstruction of afferent and efferent blood supply and/or inferior vena cava; to study postoperative outcomes in patients with focal liver lesions using transplantation technologies. MATERIAL AND METHODS: We enrolled 413 patients with parasitic lesions, primary and secondary liver tumors involving great vessels (portal vein, hepatic artery, hepatic veins, inferior vena cava, right atrium). All ones underwent liver resections with vascular resection and reconstruction, as well as liver autotransplantation in vivo, ante situ (ex situ in vivo), extracorporeal liver resections with autotransplantation (ex vivo). RESULTS: We obtained satisfactory immediate results after liver resections using transplantation technologies. CONCLUSION: Transplantation technologies in liver surgery can significantly increase resectability of tumors and survival of patients. Transplantation technologies are an important new surgical strategy and necessary option in modern hepatic surgery.

[Vascular reconstructions and transplant technologies in liver surgery (part I)]. / Sosudistye rekonstruktsii i transplantatsionnye tekhnologii v khirurgii pecheni (chast' I).

OBJECTIVE: To systematize technical aspects of liver resections with reconstruction of afferent and efferent liver blood supply and/or inferior vena cava, as well as to analyze the results of surgical treatment in patients with focal liver lesions. MATERIAL AND METHODS: The study included 413 patients with parasitic lesions, primary and secondary liver tumors with great vessel invasion (portal vein, hepatic artery, hepatic veins, inferior vena cava, right atrium). These features excluded radical liver resections without vascular resection and reconstruction, as well as liver autotransplantation in vivo, liver autotransplantation ante situ (ex situ in vivo), extracorporeal liver resections with autotransplantation (ex vivo). RESULTS: Surgical interventions were systematized depending of surgical tactics and techniques, technical complexity, type and number of reconstructed vessels, the use of total vascular isolation and cold preservation techniques, resection and reconstruction of great vessels. Thus, 4 gradations were allocated (Grade I-IV). The definition of transplantation technologies in liver surgery was proposed. CONCLUSION: Transplantation technologies in liver surgery include liver resections supplemented with vascular reconstruction of afferent and efferent liver blood supply, inferior vena cava including total vascular isolation of liver under normo- or hypothermia. These measures can significantly extend the possibilities of resection.

Interstitial Glucose Metabolism Monitoring as an Additional Method for Objective Assessment of Donor Liver, Prediction and Immediate Diagnosis of Early Graft Dysfunction.

The current clinical practice of assessing the quality and suitability of a donor liver for human transplantation does not exclude cases of primary graft dysfunction of the transplanted organ and, at the same time, leads to an unreasonable refusal to transplant a significant number of functionally suitable organs. In this regard, searching for new methods for additional objective assessment and monitoring of the state of donor organs in the peritransplant period is relevant. The aim of the study was to determine the clinical utility of monitoring interstitial concentrations of glucose and its metabolites to assess the viability and functional state of a donor liver before and after human transplantation. Materials and Methods: A retrospective observational single-center study included 32 cases of liver transplantation. Along with standard methods for assessing the initial function of grafts during the first week after surgery, interstitial (in the transplanted liver) concentrations of glucose and its metabolites were monitored. In 18 cases, the interstitial glucose metabolism was also studied during static cold storage (SCS). Results: With the development of early allograft dysfunction (EAD), compared with the uneventful post-transplant period, statistically significantly higher interstitial lactate concentrations were observed as early as 3 h after reperfusion: 12.3 [10.1; 15.6] mmol/L versus 7.2 [3.9; 9.9] mmol/L (p=0.003). A value above 8.8 mmol/L may be considered as a criterion for the immediate diagnosis of EAD (sensitivity - 89%, specificity - 65%).Interstitial lactate concentration at the end of SCS and the area under the "lactate concentration-SCS duration" curve were associated with the initial graft function. Values of these parameters greater than 15.4 mmol/L and 76.1 mmol/L·h, respectively, with a sensitivity of 100% in both cases and a specificity of 77 and 85%, may be used to assess the risk of primary EAD. Conclusion: Monitoring of interstitial concentrations of glucose and its metabolites, primarily, lactate, is an objective additional method for the assessment of the donor liver viability both during SCS and in the early postoperative period.

[Bilary anastomotic strictures after right lobe living donor liver transplantation: a single-center experience]. / Biliarnye anastomoticheskie striktury posle transplantatsii pravoi doli pecheni ot zhivogo rodstvennogo donora: opyt odnogo transplantatsionnogo tsentra.

OBJECTIVE: To determine the incidence of AS after right lobe living donor liver transplantation with various biliary reconstructions and to identify the predictors of this complication. MATERIAL AND METHODS: A retrospective and prospective analysis included 245 RLLDLTs for the period 2011-2018 at the Burnazjan Federal Medical Biophysical Center. The results of transplantations in 207 patients aged 19-68 years (median 43 years) were assessed. There were 82 men and 125 women. Follow-up period ranged from 10 to 98 months (median 35 months). We analyzed the relationship between surgical characteristics (preoperative data of recipients and donors, graft parameters, technical features of biliary reconstruction and features of post-transplantation period) and incidence of anastomotic strictures. A total of 58 parameters were analyzed. RESULTS: AS occurred in 20 (9.7%) recipients. Median AS-free period was 5 months (range 1-44). In 17 (85%) patients, AC developed within a year after surgery. Cumulative 1-, 2- and 5-year incidence of AS was 8.3%, 8.9%, and 11%, respectively. Significant predictors of AS were impaired arterial blood supply to the graft (HR 7.8, 95% CI 2.3-26.0, p<0.001), biliary leakage ISGLS class B or C (HR 5.0, 95% CI 2.0-12.8, p<0.001), early allograft dysfunction (HR 4.2, 95% CI 1.5-11.6, p=0.006) and female recipient (HR 3.2, 95% CI 1.1-9.9, p=0.04). In our sample, variant biliary anatomy of the graft and recipient liver, as well as technical features of biliary reconstruction did not affect the risk of AS. CONCLUSION: Variant biliary anatomy of potential donor alone should not be considered as a contraindication for organ donation and right liver lobe transplantation. Precise surgical technique, high transplantation activity, as well as experience of reconstructive interventions on the bile ducts during other operations can significantly reduce the incidence of AS after RLLDLT up to 9.7%.

Raman and Thompson regimes of amplification in a wiggler with noncollinear laser and electron beams.

The collective and single-electron amplification regimes of a noncollinear free-electron laser (FEL) are studied within the framework of dispersion equations. In the limit of small-signal gain the growth rates and the conditions for self-amplified excitations are found for the collective (Raman) and single-electron (Thompson) regimes. The Raman regime is shown to be preferable for the coherent spontaneous second harmonic generation by ultrarelativistic electron beams. Raman excitations in a noncollinear FEL, e.g., in an FEL without inversion, are favored by the noncollinear geometry of the electron and the laser beams, and by the relativity of the beam electrons.