Objective: to assess the effi cacy and safety of combining sequential dual hypothermic oxygenated machine perfusion (DHOPE), controlled oxygenated rewarming (COR), and normothermic machine perfusion (NMP) with ischemia-free liver implantation (IFLI) for transplants obtained from high-risk expanded criteria donors (ECDs).

Materials and methods. The study presents two cases of liver transplantation performed using the combined DHOPE-COR-NMP-IFLI protocol in May and June 2025 at the Shumakov National Medical Research Center of Transplantology and Artifi cial Organs. Liver allografts were procured from brain-dead ECDs. Perfusion was carried out using a cardiopulmonary bypass (CPB) machine following a period of static cold storage (SCS). The allografts were subsequently transplanted into recipients under continuous NMP after meeting viability criteria. The reproducibility and safety of the IFLI approach within the combined protocol were evaluated through descriptive analysis of donor characteristics, perfusion parameters, and intra- and postoperative outcomes in the recipients.

Results. In both cases, the grafts met the established viability criteria despite pronounced macrovesicular steatosis (95% and 80%, respectively). In Case No. 1, all viability parameters were achieved after 4 hours of NMP. In Case No. 2, lactate clearance was suboptimal, reaching the acceptable threshold of 4.1 mmol/L only after 6 hours of perfusion. No post-perfusion syndrome or hemodynamic instability occurred in either recipient during graft reperfusion. Both recipients met the criteria for early allograft dysfunction, with cytolysis levels of 6562.9 and 1610.4 U/L, and 3822 and 2662 U/L, respectively. The recipients were discharged on postoperative days 17 and 34 without serious complications (Clavien–Dindo ≥IIIb). At 4- and 5-month follow-up, no transplant- or preservation-related complications were observed.

Conclusion. The combined application of sequential machine perfusion (DHOPE-COR and NMP) with IFLI is a safe and eff ective dynamic preservation strategy. This approach enables the successful use of liver grafts from ECDs by minimizing ischemia–reperfusion injury.

Objective: to justify the rational selection of maintenance immunosuppressive therapy following liver transplantation (LT).

Materials and methods. The study included 42 recipients of deceased donor liver grafts, observed for periods ranging from 1 month to 15 years LT. The mean age at transplantation was 49.4 ± 7.0 years. All patients received everolimus in combination with low-dose extended-release tacrolimus. Indications for everolimus therapy were tacrolimus-induced nephrotoxicity (n = 13), history of hepatocellular carcinoma (HCC, n = 21), and development of de novo malignancies at non-hepatic sites (n = 8). Target trough concentrations were 2–3 ng/mL for tacrolimus and 3–8 ng/mL for everolimus. Adverse events of everolimus and serum cholesterol dynamics were assessed at 12, 36, 60, and 120 months after conversion to this regimen, and compared with data from 20 randomly selected recipients maintained on tacrolimus monotherapy. Estimated glomerular filtration rate (eGFR) was calculated using the CKD-EPI equation at the same time points. Liver stiffness (kPa) was measured by transient elastography once at study completion. In patients with a history of HCC, baseline alpha-fetoprotein (AFP) levels were also taken into account.

Results. Long-term use of everolimus with low-dose extended-release tacrolimus did not impair renal function (baseline GFR: 84.13 ± 16.70 mL/min/1.73 m2; final GFR: 84.99 ± 21.30 mL/min/1.73 m2). However, serum cholesterol levels were consistently higher compared with tacrolimus monotherapy (12 months: 5.7 ± 0.91 vs 4.01 ± 1.21 mmol/L; 120 months: 5.52 ± 1.51 vs 4.58 ± 0.72 mmol/L). Among 21 patients with a history of HCC, recurrence or progression occurred in 6 patients (30%), which was associated with elevated baseline AFP levels prior to LT (429.2 ± 306.9 U/mL; Z = 4.2, p = 0.0001). Liver stiffness, assessed once at the endpoint of the retrospective study, averaged 4.8 ± 1.8 kPa, corresponding to F0–1 by the METAVIR scale.

Conclusion. Long-term maintenance therapy with everolimus combined with low-dose extended-release tacrolimus after LT is safe and helps mitigate calcineurin inhibitor (CNI) nephrotoxicity. Nevertheless, this regimen does not prevent recurrent HCC, which depends on the biological activity of the tumor.

Kidney transplantation (KT) is the treatment of choice for patients with end-stage renal disease (ESRD), off ering superior survival and quality of life compared with dialysis. Several observational studies have investigated the infl uence of hemodialysis (HD) and peritoneal dialysis (PD) on post-transplant outcomes.

Objective: to assess the effect of dialysis modality prior to KT on outcomes during the fi rst two years after transplantation.

Materials and methods. The study included 95 KT recipients, divided into two groups: (1) patients previously treated with PD (n = 45) and (2) patients previously treated with HD (n = 50). The groups were comparable in age, dialysis duration, and immunosuppressive therapy regimens. The mean follow-up period was 19.4 ± 6.4 months.

Results. Delayed graft function (DGF) occurred less frequently in the PD group (17.8%) compared with the HD group (34%), although the diff erence did not reach statistical signifi cance (p = 0.08). Patients in the HD group required signifi cantly more rehospitalizations, with a median of 2.24 [1–3] compared to 1.9 [0–2.5] in the PD group (p = 0.01). Infectious complications were also more common among HD patients (62% vs 42%, p = 0.005). In particular, bacterial infections occurred signifi cantly more often in the HD group (63% vs 43%, p = 0.0001), whereas viral and fungal infections were detected at similar frequencies in both groups (p > 0.2). The incidence of graft rejection was comparable between groups. Two-year graft survival (91% in PD vs 94% in HD, p = 0.8) and patient survival (94% in PD vs 96% in HD, p = 0.9) did not diff er signifi cantly. Likewise, serum creatinine and daily proteinuria at the end of follow-up showed no statistically signifi cant diff erences (p = 0.7 and p = 0.3, respectively).

Conclusion. In this study, patients who received PD prior to transplantation showed more favorable post-transplant outcomes, including a signifi cantly lower frequency of rehospitalizations and infectious complications, as well as a trend toward reduced DGF. However, two-year graft and patient survival were similar between the PD and HD groups.

Swyer–James–MacLeod syndrome is a rare disease characterized by emphysematous transformation of an entire lung or lobe. Traditionally, the main treatment method has been surgical resection of the aff ected lung or lobe to reduce compression of adjacent healthy lung tissue and improve vital lung capacity. This article presents a clinical case of successful endoscopic treatment in a patient with emphysematous transformation of the entire lung, who was referred to the transplant center as a potential candidate for lung transplantation.

Objective: to identify donor and recipient factors associated with the risk of loss of graft function in recipients of kidney grafts from expanded-criteria, brain-dead donors.

Materials and methods. A retrospective multicenter cohort study included 254 donors who met the UNOS expanded-criteria defi nition and 444 corresponding recipients. Donor and recipient characteristics, perioperative parameters, and post-transplant outcomes were analyzed using single- and multivariable Cox regression models.

Results. Mean donor age was 58.3 ± 4.8 years, and median cold ischemia time was 14.4 [12.3–17.0] hours. Mean recipient age was 51.6 ± 9.6 years. Class I antihuman leukocyte antigen (anti-HLA) antibodies (mean fl uorescence intensity [MFI] >500) were detected in 40 (9.2%) recipients, and class II antibodies in 56 (12.8%). Delayed graft function occurred in 34.3% of recipients. Multivariate analysis revealed that lower donor minimum glomerular filtration rate (GFR) (HR = 0.98; 95% CI 0.965–0.997; p = 0.023) and higher combined donor ALT + AST levels (HR = 1.208; 95% CI 1.063–1.372; p = 0.004) were signifi cantly associated with an increased risk of graft loss. Donor age was not a significant predictor. Among recipient factors, diabetes mellitus with target-organ damage (HR = 3.727; 95% CI 1.380–10.07; p = 0.009), nephropathy of unknown origin (HR = 3.816; 95% CI 1.212–12.02; p = 0.022), and elevated class II antiHLA antibody levels (HR = 1.125 per 1000 MFI; 95% CI 1.039–1.218; p = 0.004) were the strongest predictors of graft loss. When recipient GFR at three months post-transplant was included in the model, the signifi cance of donor-related factors (GFR, ALT, AST) was negated.

Conclusion. Recipient-related predictors of graft loss are diabetes mellitus, unknown etiology of initial CKD, high class II anti-HLA antibody levels, and reduced GFR at three months post-transplant. Donor-related predictors of graft loss are minimum GFR during the entire period of donor hospitalization and elevated ALT/AST levels; however, these factors become statistically insignificant when recipient GFR three months after KT is included in the model. 

Objective: to evaluate the impact of kidney transplantation (KT) on erectile function and reproductive health in men with chronic kidney disease (CKD).

Materials and methods. A prospective study was conducted involving 276 male patients (mean age 44.3 ± 5.8 years) with CKD who underwent KT from a living related donor. Erectile function was assessed using the International Index of Erectile Function (IIEF-5). Penile hemodynamics were evaluated by Doppler ultrasonography of the penile arteries, while hormonal status was determined by measuring serum testosterone, luteinizing hormone, and follicle-stimulating hormone (FSH) levels. Reproductive function was assessed by semen analysis and testicular volume measurements at five time points: baseline, at high azotemia, and at 3, 6, and 12 months post-transplantation. Management of post-transplant erectile dysfunction included phosphodiesterase type 5 inhibitors (IIEF-5, 5 mg daily for 3 months, followed by 20 mg on demand), pelvic fl oor muscle exercises, vacuum therapy, and physiotherapy.

Results. After 12 months of follow-up, erectile function was fully restored in 65.6% of patients. The proportion of moderate-to-mild erectile dysfunction decreased to 9.4%, while mild dysfunction persisted in 25% of patients, primarily due to residual vascular, hormonal, and psychoemotional factors. The mean IIEF-5 score increased signifi cantly from 13.2 ± 0.1 to 21.2 ± 0.2 (p < 0.001). The average peak systolic velocity in the right cavernous artery rose from 5.6 ± 0.1 cm/s to 7.2 ± 0.1 cm/s (p < 0.001). Serum testosterone levels increased from 4.6 ± 0.1 ng/ml to 5.6 ± 0.2 ng/ml (p < 0.001), and the proportion of patients with normospermia grew from 37.3% to 61.2% (p < 0.001). Erectile dysfunction persisted in 34.4% of patients despite therapy.

Conclusion. The findings demonstrate a significant restoration of erectile function and fertility in most patients following KT and supported by comprehensive management of residual vascular, hormonal, and psychoemotional disorders.

Background. Liver transplantation (LT) remains the only life-saving option for children with end-stage liver disease. In Uzbekistan, a national LT program was launched in 2018; however, pediatric LT had not been performed until recently.

Objective: to report the fi rst documented case of related pediatric LT in the Republic of Uzbekistan and to highlight key aspects of postoperative management, including rejection crises, recurrent autoimmune hepatitis (AIH), and the innovative use of bortezomib for treating steroid-resistant rejection.

Materials and methods. A 15-year-old patient with liver cirrhosis secondary to AIH was selected for transplantation. The right hepatic lobe from a living donor was transplanted following comprehensive preoperative evaluation and preparation. The procedure involved surgical intervention followed by a multistage postoperative treatment protocol.

Results. The transplant procedure was successful. However, in the early postoperative period, the patient developed a rejection crisis that proved resistant to standard therapy with glucocorticosteroids and antithymocyte globulin. Subsequent evaluation revealed a recurrent AIH. Bortezomib was administered as part of the therapeutic strategy, leading to normalization of laboratory parameters and restoration of graft function.

Conclusion. This fi rst case of pediatric LT in Uzbekistan demonstrates the feasibility of performing complex surgical interventions and managing challenging postoperative complications. The use of bortezomib for steroid-resistant rejection associated with AIH highlights a potentially promising therapeutic approach. These results mark an important step forward in the development of transplant care in the country.

Background. Heart transplantation (HT) remains the primary surgical treatment for children with end-stage chronic heart failure (CHF). More than 30% of pediatric HT candidates require shortor long-term mechanical circulatory support (MCS) due to refractoriness to medical therapy. In recent years, the use of left ventricular assist device (LVAD) systems has expanded not only in teenagers and middle-aged children but also in younger and smaller patients.

Objective: to investigate the perioperative course of emergency LVAD implantation in children with critical hemodynamic compromise (INTERMACS profile I) requiring short-term MCS via peripheral venoarterial extracorporeal membrane oxygenation (VA-ECMO).

Materials and methods. We studied 25 patients under 18 years of age (12 girls, 48.0%; 13 boys, 52.0%) who had a HeartMate III LVAD LVAD implanted between January 1, 2021, and June 30, 2024. The severity of pre-implantation CHF was classified according to INTERMACS profiles: I (n = 4, 16.0%), II (n = 9, 36.0%), and III (n = 12, 48.0%). Patients were divided into two groups based on the need for VA-ECMO prior to LVAD implantation: the VA-ECMO–LVAD group (n = 4, 16.0%) and the LVAD group (n = 21, 84.0%).

Results. The VA-ECMO–LVAD group (n = 4) did not differ significantly from the LVAD group (n = 21) in age, sex, or underlying disease. Intraoperatively, there were no significant differences between groups in the duration of cardiopulmonary bypass, doses of sympathomimetic cardiotonics, or the use of inhaled nitric oxide. The VA-ECMO–LVAD group showed a trend toward greater intraoperative blood loss and transfusion requirements (p > 0.05). In the postoperative period, blood loss volumes were similar between groups. However, patients in the VA-ECMO–LVAD group more frequently required re-sternotomy (25% vs 9.5%, p < 0.05), had a longer duration of postoperative mechanical ventilation (1.79-fold, p < 0.05), more often required renal replacement therapy (2.5-fold, p = 0.166), and had significantly longer ICU stays (2.75-fold, p = 0.041). In the VA-ECMO–LVAD group, the incidence of severe acute right ventricular dysfunction was significantly higher (25.0% vs 9.5%, p = 0.016). No significant difference in postoperative hospital mortality was observed between the two groups.

Conclusion. Emergency implantation of an LVAD system in children with critical hemodynamic instability requiring preoperative short-term MCS using peripheral VA-ECMO has demonstrated high effectiveness. However, careful consideration should be given to the presence and severity of multiple organ dysfunction before and after LVAD implantation, as well as perioperative blood loss. These factors largely determine the anesthetic and resuscitative management strategies, as well as the immediate outcomes of long-term MCS.

Objective: to assess the gas transport performance of new polypropylene (PP) membranes manufactured by Cobetter Filtration^® (China) for use in extracorporeal circulation, and to compare their efficacy with the original 3M^® PP membrane (USA) using both an extracorporeal hydrodynamic test bench and in vivo animal experiments.

Materials and methods. Three experimental groups were established for bench and animal testing: a) Experimental – PP membrane 380/280 (n = 3); b) Experimental – PP membrane 300/200 (n = 3); c) Control – original 3M^® PP membrane (n = 3). A total of 18 oxygenators were evaluated, including 12 experimental oxygenators with the Cobetter Filtration^® membranes and 6 control oxygenators with 3M^® membranes. The primary outcome was the oxygenation index (OI), reflecting the gas transport function of the membrane oxygenators.

Results. During bench testing, the OI of the PP 300/200 membrane decreased from 509 ± 27 at baseline to 422 ± 31 after 240 minutes, showing no significant difference compared with the PP 380/280 membrane, which decreased from 487 ± 15 to 385 ± 20 (p > 0.05). In contrast, oxygenators with the original 3M^® membrane exhibited signifi cantly higher OI values, declining from 713 ± 46 to 612 ± 39 over the same period. In animal experiments, the initial OI in the 3M^® control group exceeded the threshold of 300, measuring 439 ± 13, whereas the experimental groups recorded lower values: 392 ± 27 (PP 380/280) and 411 ± 8 (PP 300/200), with p < 0.05. By 60 minutes, OI values were similar across all groups (p = 1). At the end of the 5-hour acute observation, OI values were 325 ± 29 (PP 380/280) and 355 ± 33 (PP 300/200), with no statistically signifi cant difference between the experimental groups (p > 0.05).

Conclusion. The experimental PP membranes demonstrated comparable effectiveness to the original 3M® products, suggesting their potential for enhancing the safety and biocompatibility of extracorporeal circulation procedures.

Background. According to available literature, recipients of solid organ transplants have a progressively increased risk of developing aseptic necrosis and osteoarthritis due to long-term corticosteroid and immunosuppressive therapy. Approximately 5% of transplant recipients develop femoral head avascular necrosis (FHAN). In such cases, the gold standard of treatment is total hip replacement (THR). However, this approach carries a high risk of postoperative infectious complications.

Clinical case. A patient was admitted in Moscow at the City Center for Bone and Joint Endoprosthetics, Botkin Hospital for a planned THR. Six years earlier, she had undergone a heart transplant. Her clinical profi le was further complicated by multiple comorbidities, placing her in a highrisk category for perioperative complications according to the ASA classifi cation.

Conclusion. Despite the high intraoperative and postoperative risks, THR was the only viable option to improve the patient’s quality of life, given the progression of FHAN.

Objective: to propose and justify approaches for improving the classical hemodynamic test bench, widely used to model the integration of mechanical circulatory support (MCS) systems.

Materials and methods. The hemodynamic test bench consisted of multiple containers and resistors simulating systemic and pulmonary circulation, enabling the study of physiological conditions in heart failure (HF). The setup also included an auxiliary circulatory support pump and a pulsatile flow generator.

Results. A mathematical model of the cardiovascular system was developed, capable of reproducing physiological states under conditions of pump-assisted circulation and pulsatile flow. Comparative evaluation of experimental and modeling results highlighted the advantages and limitations of different modeling methods.

Conclusion. Based on these findings, strategies for further development of the hemodynamic test bench, aimed at enhancing its ability to simulate the impact of mechanical circulatory support on key hemodynamic parameters, were formulated and justified.

The aim of this study was to conduct a comparative analysis of the bioregulatory role of mesenchymal stem cells (MSCs) in the liver under physiological conditions, in acute and chronic injury with fibrotic remodeling, and during therapeutic correction by implanting exogenous MSCs from healthy tissues into the body. The analysis showed that hepatic MSCs maintain structural homeostasis by interacting with tissue myofibroblasts and migrating immune cells. In acute liver injury that does not deplete adaptive reserves, hepatic (resident) MSCs regulate tissue homeostasis.. Chronic injury that depletes adaptive reserves activates both immune cells and hepatic MSCs, leading to liver inflammation and the transdifferentiation of MSCs into myofibroblasts. These activated fibroblasts overproduce extracellular matrix components, thereby driving liver fibrosis progression. Exogenous apoptotic MSCs from healthy auto- or allogeneic tissues, when administered in cases of chronic liver injury, can compensate for deficient regulatory factors and restore metabolic regulation and structural homeostasis through their paracrine and trophic activity. Their therapeutic potential is maximized when their regulatory properties are enhanced prior to administration and when applied in recipients without irreversible liver injury.

Silk is a promising natural biomaterial that combines mechanical strength, biocompatibility, and controlled biodegradation, making it highly suitable for scaffold creation for clinical practice. This study investigates how different processing methods influence the morphological and mechanical characteristics of silk-based scaffolds. The fi ndings showed that varying the processing conditions facilitates the production of materials with tailored properties, ranging from dense, mechanically robust structures to porous, rapidly degradable scaffolds. Highdensity samples (Fibroplen-Atlas) exhibited substantial mechanical stability, making them promising candidates for surgical applications in mechanically demanding areas such as ligaments, fascia, and tendons. In contrast, more porous scaffolds (Fibroplen-Gas) demonstrated accelerated biodegradation, which is advantageous for soft tissue regeneration. These results highlight the potential of silk scaffolds for personalized applications, where the balance between mechanical stability and biodegradation rate can be adjusted according to specific clinical needs.

The growing number of patients with severe organ diseases, along with the increasing demand for retransplantations, has intensified the global shortage of donor organs – the primary limitation to expanding transplant programs. Advances in genetic engineering and cell therapy technologies are opening new opportunities for the use of animal organs in human transplantation. Enhancing the effi cacy and safety of this approach requires overcoming signifi cant immunological and physiological barriers inherent in xenotransplantation. This review summarizes recent progress in genetic modification of donor animals, use of cell-based therapy in xenotransplantation, and prospects for clinical application. 

Objective: to evaluate the association between carriage of the rs1800469 polymorphism of the TGFB1 gene and the risk of post-transplant complications, rejection episodes, and infectious diseases in pediatric liver recipients.

Materials and methods. The study included 219 pediatric liver recipients (92 boys, 127 girls), aged 2.4 to 204 months (median 8 months). Indications for liver transplantation (LT) were end-stage liver failure resulting from congenital or acquired liver diseases. Genotyping of the TGFB1 rs1800469 polymorphism was performed using real-time polymerase chain reaction (PCR) with TaqMan probes.

Results. A comparative analysis of the allele frequency of rs1800469 of the TGFB1 gene was performed in three groups of pediatric liver recipients: (1) with versus without post-transplant complications, (2) with versus without rejection episodes, and (3) with versus without infectious complications. In all groups, allele frequencies conformed to Hardy–Weinberg equilibrium (p > 0.05). No significant differences in rs1800469 variant distribution were observed between recipients with and without overall complications or between those with and without rejection episodes. However, marked differences emerged between recipients with and without infectious complications: the C/C genotype was 1.9 times less frequent (p = 0.0102), the C allele was 1.3 times less frequent (p = 0.0175), and the T allele was 1.4 times more frequent (p = 0.0175) in the infection group. Under a dominant inheritance model, carriers of the T allele (C/T + T/T) had 2.53-fold higher odds of infection compared with those with the homozygous C/C genotype in the group of recipients with infections than in those without (p = 0.0077).

Conclusion. In pediatric liver transplant recipients, the TGFB1 polymorphic variant rs1800469 is not associated with either a complicated post-transplant course or the occurrence of graft rejection episodes. However, carriers of the T allele appear to have an increased risk of infectious complications compared with those with the homozygous C/C genotype. These fi ndings suggest that the rs1800469 T allele may serve as a genetic marker for increased susceptibility to infections and could be considered in strategies for prevention of complications and individualized adjustment of immunosuppressive therapy.

The use of expanded criteria donors (ECDs) is an effective strategy to increase the availability of organs for transplantation. However, in Russia, there have been no large-scale studies evaluating the outcomes of kidney transplantation (KT) from ECDs. In Moscow, through successful implementation of an original organ donation model, considerable experience has been accumulated in managing donors who meet the UNOS expanded criteria for kidney donation. This paper presents the epidemiological characteristics of donors and recipients, as well as the medium-term outcomes of KT from ECDs. The study represents the first multicenter cohort study in the Russian Federation dedicated to kidney transplants from ECDs. The database was developed using systematized donor information from the Moscow Coordination Center for Organ Donation at Botkin Hospital for the period 2021–2022. During this time, 254 donors meeting UNOS expanded criteria underwent organ explantation at 21 hospitals in Moscow. The follow-up period for KT recipients was limited to four years. Recipient survival at 4 years after transplantation was 0.882 [95% CI 0.839–0.927], while overall graft survival (loss from any cause) was 0.806 [95% CI 0.739–0.880] and death-censored graft survival was 0.887 [95% CI 0.825–0.952]. Primary graft function was observed in 61.4% of recipients who received kidneys from ECDs. The medium-term survival rates of both recipients and grafts are acceptable and comparable to those reported in international studies, confirming the safety and effectiveness of expanding donor criteria to increase the number of kidney transplants.

Dyslipidemia in patients with chronic kidney disease (CKD), particularly those on renal replacement therapy (RRT), is a major risk factor for cardiovascular complications. The pathogenesis of lipid metabolism disorders in this population is multifactorial and infl uenced by the underlying kidney disease, the specific characteristics of RRT, and, in transplant recipients, the effects of immunosuppressive therapy. Despite the high prevalence and clinical significance of dyslipidemia in CKD, therapeutic strategies for its correction remain insuffi ciently studied. This review analyzes current pharmacologic approaches to the management of dyslipidemia and evaluates the potential for their application in patients receiving RRT. Literature search was conducted using electronic databases Medline/PubMed (https://pubmed.ncbi.nlm.nih.gov) and eLIBRARY/Russian Science Citation Index (https://www.elibrary.ru).

Objective: to perform a comparative analysis of donor lung preconditioning protocols in donors after circulatory arrest, followed by normothermic ex vivo lung perfusion (EVLP), using two approaches: topical lung cooling and continued artificial ventilation after circulatory arrest.

Materials and methods. The study was conducted on male Grey Giant rabbits weighing 4.5–5.0 kg (n = 20). Group 1: Donor lung preconditioning after circulatory arrest using topical cooling (n = 10). Group 2: Donor lung preconditioning after circulatory arrest with continued artificial ventilation in protective modes (n = 10). To evaluate the viability and functional state of donor lungs following preconditioning and cold preservation, both groups underwent normothermic EVLP. Assessments included lactate concentration, perfusate gas composition, endoscopic evaluation of the tracheobronchial tree, and subsequent morphological examination.

Results. After 60 minutes of cold preservation, all grafts demonstrated satisfactory gas exchange function during normothermic EVLP. In Group 1 (topical cooling), the oxygenation index (OI) at 60 minutes was 552 (461–599) and increased to 558 (462–603) at 120 minutes. In Group 2 (continuous artifi cial ventilation), OI was 358 (343–368) at 60 minutes, with a tendency to increase to 374 (349–395) at 120 minutes. The difference between the groups was statistically signifi cant (p = 0.000). Lactate levels in both groups showed an upward trend, with a mean value of 6.99 ± 0.81, and no statistically significant intergroup differences were observed (p > 0.05).

Conclusion. The study demonstrates the potential advantages of using topical cooling as part of the donor lung preconditioning protocol after cessation of eff ective circulation, employing a dextran40-based preservation solution at all stages. This approach may increase the number of donor lungs suitable for transplantation.

Objective: to identify key patterns of calcification in explanted bioprosthetic heart valves (BHVs) using cluster analysis of computed tomography-derived graphical data.

Materials and methods. The study included 11 UniLine BHVs that were routinely explanted during reoperations for structural valve dysfunction. Computed tomography was used to obtain DICOM images of each sample, followed by generation of maximum intensity projections and segmentation of the valves into individual leaflets (n = 33). The images were pre-processed using binary thresholding to differentiate calcified regions from non-calcified biological tissue. Cluster analysis was performed using various algorithms: Gaussian mixture models, Ordering Points To Identify the Clustering Structure (OPTICS), k-means clustering, agglomerative (hierarchical) clustering, and spectral clustering. A basic quantitative method assessing the proportion of pixels corresponding to calcified areas was used for comparison. The performance of clustering algorithms was evaluated using the silhouette score. The presence of calcium deposits in the valves and the accuracy of binary thresholding were further verified histologically by alizarin red S staining of valve cryosections.

Results. Data preprocessing based on image binarization yielded a maximum silhouette score of 0.55. Among the clustering algorithms, the highest silhouette scores were achieved with the agglomerative (0.55) and k-means (0.54) methods; however, both demonstrated substantial data imbalance, with up to 85% of samples grouped within a single cluster, limiting their practical applicability. The most balanced clustering was achieved using spectral clustering (silhouette score 0.45) and the basic quantitative approach (0.44). Both methods identified three distinct patterns of bioprosthetic valve leaflet calcification: (1) non-calcified leaflets, (2) partial calcification, and (3) total calcification.

Conclusion. Three key calcification patterns were identified in explanted BHVs – absence of calcium, partial calcification, and total calcification. Spectral clustering and the basic quantitative method demonstrated the most balanced results, while other algorithms showed pronounced cluster imbalance. Heat map analysis revealed that in partial calcification, mineral deposition typically begins in the commissural and dome regions of the leaflets, near the free edge, and in total calcification, extends across the entire dome and leaflet base.

Currently, there is a growing number of repeat cardiac interventions in children who have previously undergone surgery for congenital heart defects. This has renewed interest in identifying reconstructive materials that are resistant to the host’s defense mechanisms. Among such materials, cryopreserved homografts in various modifi cations are of particular relevance. Numerous studies have reported on the use of these prostheses in diff erent anatomical positions; however, cases involving simultaneous implantation of multiple homografts in a single patient for correction of congenital heart defects remain rare. To our knowledge, there are no published reports describing the use of a mitral homograft as a tricuspid valve substitute in combination with prosthetic pulmonary valve replacement using an allograft conduit. This report presents the first successful case of double valve replacement in a pediatric patient who had previously undergone radical correction of a double outlet right ventricle.