Search Results (974)

Polymer coatings are integral to nearly every modern cardiovascular and endovascular device, including drug-eluting stents (DESs) and drug-coated balloons (DCBs), bioabsorbable vascular scaffolds (BVSs), occluders, grafts, and catheter and guidewire hydrophilic surfaces. Persistent complications, including late stent thrombosis, delayed endothelialization, hypersensitivity, and restenosis, show that coatings actively shape biological responses rather than acting as inert drug carriers. Their surface chemistry, drug release kinetics, and degradation behavior are upstream determinants of blood– and tissue–material responses that govern healing and failure. This review frames coating selection as a structure–property–biological response problem. It surveys the major classes of synthetic polymer coatings and the defining surface and bulk properties. This review also examines how composition and architecture control drug release, and traces the interfacial cascade of protein adsorption, coagulation and complement activation, platelet and leukocyte responses, and neutrophil extracellular trap (NET) formation. These mechanisms are linked to contemporary design strategies that improve hemocompatibility, limit thrombosis, promote endothelial recovery, and tune degradation, and to the standardization and translation gaps that remain. The central message is that polymer coatings are not biologically equivalent. Their surface chemistries and degradation profiles determine the thrombo-inflammatory outcomes. Therefore, coating design should be guided by intended biological response, not drug release alone. Full article

Background/Objectives: Optimal vascular access remains a critical determinant of outcomes in patients undergoing maintenance hemodialysis. While an arteriovenous fistula (AVF) is generally preferred over an arteriovenous graft (AVG), the impact of obesity and antithrombotic therapy on access-related complications remains incompletely defined. This study evaluated the association between vascular access type, obesity status, and adverse outcomes in a large real-world cohort. Methods: We conducted a retrospective cohort study using de-identified electronic health record data from the TriNetX Global Collaborative Network. Adult patients (≥18 years) receiving maintenance hemodialysis were stratified by vascular access type (AVF vs. AVG), body mass index (normal: 18.5–24.9 kg/m², obese: ≥30 kg/m²), and antithrombotic medication exposure. Propensity score matching (1:1) was performed within BMI strata. Primary outcomes included vascular access thrombosis, AVG failure, and AVF failure. Time-to-event analyses used Kaplan–Meier and Cox proportional hazards models. Results: AVG was associated with significantly higher rates of thrombosis and access failure compared with AVF in both obese and normal-weight cohorts (all p < 0.0001). In patients with obesity, thrombosis rates increased from 10.47% (AVF) to 17.54% (AVG) at 3 months to 34.32% versus 42.24% at 5 years. Kaplan–Meier analysis demonstrated early and persistent separation of thrombosis-free survival curves, with AVG associated with increased risk (HR 1.23; 95% CI, 1.07–1.41; log-rank p = 0.0001). Antithrombotic therapy reduced absolute risks but did not eliminate the relative disadvantage of AVG. Conclusions: In this large real-world cohort, AVG was consistently associated with higher risks of thrombosis and access failure compared with AVF, regardless of obesity status or medication exposure. These findings support preferential use of AVF and highlight the need for individualized vascular access strategies in patients undergoing hemodialysis. Full article

Vein graft restenosis is a leading cause of long-term failure after coronary artery bypass grafting (CABG), driven by maladaptive vascular smooth muscle cell (VSMC) responses to arterialization-induced inflammation. The key molecular mediators of this pathological remodeling, however, remain incompletely defined. Here, we integrated multi-omics analyses of human and canine vein graft specimens with in vitro functional assays to identify tenascin-C (TNC)—a matricellular extracellular matrix protein—as a critical regulator of VSMC dysfunction. TNC was specifically enriched in a synthetic, pro-inflammatory VSMC subpopulation. Pro-inflammatory stimuli potently induced TNC expression, which was functionally linked to VSMC phenotypic modulation, hyperproliferation, and enhanced migration. Mechanistically, TNC acts upstream of NF-κB signaling; siRNA-mediated TNC knockdown significantly reduced nuclear p65 protein levels and attenuated inflammatory responses. Our integrated computational and experimental data suggest that TNC, NF-κB, and TNF-α function within a sequential pro-inflammatory signaling cascade that sustains vascular inflammation and promotes neointimal hyperplasia. These findings reposition TNC from a passive structural component to an active driver of vascular pathology and highlight the TNC–NF-κB axis as a candidate target for therapeutic intervention to improve vein graft patency. Full article

Background: The generation of durable and hemocompatible small-diameter vascular grafts remains a major challenge in current vascular tissue engineering, as clinically available synthetic grafts are lacking hemocompatibility resulting in limited long-term patency. In recent years, fibrin has emerged as a promising scaffold material for various tissue engineering approaches due to its autologous nature, controllable fabrication, and mechanical properties. However, although pivotal for the translation into clinical application, systematic evaluation of hemocompatibility in fibrin-based small-caliber grafts is still missing. Methods: Here, the hemocompatibility of small-diameter fibrin-based grafts with and without heparin coating was compared to the current gold standard for prosthetic small-diameter vessel replacement in the form of heparin-coated ePTFE grafts using the Chandler Loop circulation model with human whole blood. Cell adhesion of thrombocytes, erythrocytes, and leucocytes was compared. Platelet activation, activation of the complement system, and plasmatic coagulation activity were assessed by ELISA analyses for P-Selectin, complement sC5b-9, and thrombin–antithrombin complex, respectively. Scanning electron microscopy (SEM) was performed to evaluate interactions and thrombocyte activation on the luminal graft surfaces. Results: The short-term hemocompatibility of the fibrin-based grafts with respect to the cell-count, activation of the coagulation pathways, and thrombocyte activation was comparable to the heparin-coated synthetic grafts even without heparin coating of the bioartificial grafts. Conclusions: The findings of this early-stage analysis support fibrin as a promising scaffold material for small-diameter vascular tissue engineering. Full article

Background: Forearm nonunions represent a challenging clinical condition that significantly impairs upper limb function. Various surgical techniques have been proposed, including vascularized bone grafts. Although these procedures are not considered first-line treatment, they play a crucial role in complex or recalcitrant cases, particularly after failure of conventional methods, where their superior biological potential can significantly enhance bone healing. Despite the widespread use of the medial femoral condyle corticoperiosteal flap, simultaneous bilateral harvest has not been previously described in the literature. Case Presentation: We report the case of a 50-year-old male presenting with persistent nonunions of both the radius and ulna following previous osteosynthesis and revision surgery with iliac crest bone graft. The patient was successfully treated using bilateral vascularized corticoperiosteal free flaps harvested from both medial femoral condyles. Conclusions: Double vascularized corticoperiosteal free flaps may represent an effective and reliable option for the treatment of complex forearm nonunions, especially in cases with multiple previous surgical failures. To the best of our knowledge, this case represents the first report of simultaneous bilateral medial femoral condyle corticoperiosteal flap harvest. Full article

Background/Objectives: Type II endoleaks (T2ELs) remain one of the most frequent causes of aneurysm sac enlargement following endovascular abdominal aortic aneurysm repair (EVAR). While embolization may be effective in typical T2ELs with a clearly identifiable feeding vessel, management becomes more challenging when no visible communication with a side branch can be demonstrated. Emerging evidence suggests that hypertrophic vasa vasorum may contribute to aneurysm sac expansion in these atypical cases. We present a case of refractory atypical T2EL treated by open conversion and discuss the potential role of the vasa vasorum network in its pathophysiology. Case Presentation: A 77-year-old man presented with lumbar pain ten years after EVAR for a symptomatic abdominal aortic aneurysm. Computed tomography angiography demonstrated progressive aneurysm sac enlargement to 8.5 cm despite three previous translumbar embolization procedures. Multiple areas of contrast pooling were identified within the aneurysm sac, but no clear communication with a feeding side branch was observed. Owing to persistent sac expansion and symptoms, open conversion was performed with partial endograft explantation and reconstruction using a bifurcated PTFE graft. Results: After opening the aneurysm sac and evacuating the thrombus, diffuse bleeding was observed from numerous small vascular orifices distributed throughout the inner sac surface. These findings were considered consistent with a prominent vasa vasorum network. Hemostasis was achieved using a combination of figure-of-eight sutures and electrocautery. The postoperative course was uneventful, and the patient was discharged on postoperative day five. Follow-up imaging demonstrated normal graft patency without complications. Conclusions: This case supports the hypothesis that an extensive vasa vasorum network may contribute to aneurysm sac expansion in atypical T2ELs and possibly endotension after EVAR. In patients with refractory sac enlargement, open conversion remains a definitive treatment option. Further research is needed to clarify the underlying mechanisms and to explore targeted therapeutic strategies aimed at modulating angiogenesis and vascular remodeling. Full article

Background/Objectives: Successful revascularization following extremity arterial injury is critical for survival and limb salvage. Graft repair is required in ~45% of patients, with the autologous vein preferred for its efficacy and safety. When unavailable, synthetic or non-autologous grafts are associated with infection, amputation, and reduced durability. Extremity arterial injury-specific cost data are lacking, with estimates extrapolated from the general trauma literature. This study characterized the costs and post-discharge healthcare resource utilization (HCRU) for U.S. adults with extremity arterial injury undergoing graft repair. Methods: Adults with extremity arterial injury undergoing graft repair (January 2018 to March 2023) were identified from the linked PINC AI Healthcare Database and Inovalon all-payer claims. Hospitalization charges, costs, and 18-month post-discharge HCRU and costs were assessed. Two-part models estimated cost drivers, adjusted for demographics, clinical characteristics, and complications. Results: Among 964 patients, grafts were autologous (74%), synthetic (14%), other (6%), or multiple (6%). Mean initial hospitalization charges and reimbursed costs were $316,600 and $75,947, respectively. Charges/costs increased with orthopedic fracture (+$639,558/+$91,462), graft infection (+$589,921/+$84,598), and amputation (+$492,986/+$116,611) (all p < 0.05). Mean post-discharge costs were $70,222 at 6 months and $93,639 at 18 months. Initial hospitalization complications predicted increased post-discharge costs: orthopedic fracture ($138,683–$145,360) and graft infection ($389,376–$422,224) (both p < 0.01). Post-discharge aneurysm, graft infection, and thrombectomy were also associated with higher costs (all p < 0.05). Post-discharge HCRU was lowest and most stable with the autologous vein. Conclusions: In-hospital and post-discharge complications are major cost drivers following arterial graft repair. Graft infection was associated with significantly increased costs across both periods, and non-autologous graft use was associated with disproportionately higher 18-month HCRU. Full article

When placing dental implants, xenografts are most commonly used clinically to compensate for the insufficient bone volume of patients. However, xenografts have limitations including low osteoinductive capacity and prolonged healing time. This study aimed to determine whether non-thermal plasma treatment could enhance the regenerative performance of bovine cancellous bone graft (SANTA-OSS^®) in a rabbit calvarial defect model. Twenty-four adult male New Zealand white rabbits received bilateral 8 mm critical-size calvarial defects. One defect was filled with untreated SANTA-OSS (control) and the contralateral defect with plasma-treated SANTA-OSS using the ACTILINK™ Reborn device. Animals were sacrificed at 2, 4, and 8 weeks (n = 8 per group) for histomorphometric analysis. The plasma-treated group showed significantly higher new bone area (14.12 ± 0.69%, 18.93 ± 0.68%, and 32.72 ± 0.61% at 2, 4, and 8 weeks) than the control at all time points (p < 0.05). In addition, the experimental group exhibited accelerated graft resorption, larger bone marrow area, greater blood vessel area, and more TRAP-positive osteoclasts compared with the control (p < 0.05). Within the limitations of this study, non-thermal plasma treatment significantly enhanced new bone formation and promoted favorable graft remodeling, while also accelerating graft resorption, increasing bone marrow area, and improving vascularization. These findings suggest that simple chairside plasma activation can improve the regenerative performance of xenografts. Full article

Polyurethane (PU) is widely used in medical products due to its biocompatibility and mechanical properties. Electrospinning (ES) was employed to produce PU-based scaffolds intended for cardiovascular devices (CVD) from blends of Carbothane (Carb) with human serum albumin (HSA), dimethylacetamide (DMA), and drugs. Sirolimus (SRL)—an immunosuppressive/anti-proliferative drug—and diclofenac (DF)—a nonsteroidal anti-inflammatory drug—were introduced into ES blends to produce drug-enriched scaffolds that prevent inflammation and cell overgrowth. The biocompatibility, stability, and mechanical properties of the scaffolds and SRL release were studied. The scaffolds possessed good mechanical properties and were stable in PBS and blood plasma (BP) for 120 days. The minimal SRL release rate was observed for the scaffold 3%Carb/10%HSA/DMA/SRL. A study of scaffold interaction with blood demonstrated good hemocompatibility of most scaffolds. A study of human gingival fibroblasts, endothelial cells (HUVEC and EA.hy926), and vascular smooth muscle cell interaction with scaffolds in vitro demonstrated variability in cell viability and pro-inflammatory interleukin IL-6 secretion, depending on both the scaffold composition and the cell type. The incorporation of DF into scaffolds decreased the concentration of IL-6 in the culture medium. The scaffold 3%Carb/10%HSA/DMA/SRL is the best choice for CVD in terms of hemocompatibility, endothelialization, and the induction of minimal inflammation. Full article

The article is devoted to the study of the structure, physico-mechanical properties and biocompatibility of modified conduits based on bacterial cellulose (BC) to replace injured blood vessels. It has been shown that both samples have almost the same elastic recoil and are superior to synthetic vascular grafts in terms of the parameters studied. It should be noted that the first modified sample is characterized by greater elasticity and lower tensile strength compared to the second sample; however, the physico-mechanical properties of the obtained conduits are in the range corresponding to native blood vessels. Scanning electron microscopy (SEM) demonstrated that the conduits under study had a fibrillar structure with nanosized pores that enabled the adhesion of endothelial cells on the internal surface of the vascular implant, improved elasticity under transverse pressure, and raised the elasticity modulus when stretching along the fibrils. Thermogravimetry revealed that elastic recoil formation depended on the nature of polyvinyl alcohol (PVA) interaction with the nanofibrillar structure of BC rather than on the content of polyvinyl alcohol used for modification. The MTT test results confirmed no cytotoxicity and high oxygen permeability in the studied samples, opening great opportunities for their application in regenerative biomedicine to replace injured blood vessels. Full article

Background: Large segmental bone defects remain a major challenge in reconstructive surgery, particularly in the presence of impaired vascularization. Despite advances in scaffold design and biomaterials, insufficient vascular supply continues to represent the primary limitation in bone tissue engineering, often leading to impaired osteogenesis and graft failure. Objective: This review aims to analyze the role of vascularized flaps as “living bioreactors” in bone tissue engineering, focusing on their capacity to enhance scaffold vascularization, support osteogenesis, and facilitate clinical translation. Methods: A narrative review was conducted through a structured search of PubMed, Scopus, and Web of Science using combinations of the following keywords: “bone tissue engineering”, “vascularized flaps”, “arteriovenous loop”, and “in vivo bioreactor”. Relevant preclinical and clinical studies were selected based on their contribution to vascularization strategies in scaffold-based bone regeneration, with the aim of illustrating the evolution and integration of these approaches. Results: Vascularized flaps provide an established vascular network and a biologically active microenvironment that promote scaffold integration and tissue regeneration. Periosteal flaps demonstrate strong osteogenic potential, whereas muscle and omental flaps primarily act as vascular carriers and adaptable regenerative environments. AV loop-based strategies enable intrinsic axial vascularization, ensuring rapid and homogeneous perfusion of large constructs. Hybrid approaches, including regenerative matching axial vascularization (RMAV), integrate vascularized tissues with advanced biomaterials and show promising translational outcomes. Conclusions: Vascularization-driven strategies represent a paradigm shift in bone tissue engineering, moving from passive scaffold implantation to actively engineered, vascularized constructs. The integration of microsurgical techniques with advanced biomaterials offers significant potential for the development of personalized and clinically applicable bone regeneration strategies. Full article

Background: Traditional cardiovascular risk models focus on patient-related clinical variables, while the impact of long-term environmental exposure remains insufficiently characterized in post-revascularization populations. Objective: To evaluate the association between environmental exposure and long-term mortality after coronary artery bypass grafting (CABG), and to determine whether integrated environmental measures provide additional prognostic value beyond established clinical risk factors. Methods: This retrospective multicenter cohort study included 1042 consecutive patients undergoing CABG with a median follow-up of 8.1 years. Regional environmental data were linked to individual patients. Multivariable Cox regression models were constructed using a hierarchical approach. To address collinearity among environmental variables, principal component analysis (PCA) was applied. Mean winter temperature was analyzed as a clinically interpretable proxy of overall environmental exposure. Results: During follow-up, 220 deaths (21.1%) occurred. Established clinical predictors of mortality included age, diabetes mellitus, peripheral vascular disease, and dyslipidemia. Individual environmental variables showed unstable associations due to collinearity. PCA identified a dominant environmental component explaining 82.0% of variance; however, its association with mortality did not reach statistical significance after adjustment (HR 1.17 per SD, 95% CI 0.98–1.39; p = 0.083). In contrast, higher mean winter temperature was independently associated with increased mortality (HR 1.24 per SD, 95% CI 1.05–1.48; p = 0.013) per 1 °C increase, with evidence of non-linearity. Conclusions: Environmental exposure represents a relevant component of long-term risk after CABG. While individual environmental variables are highly correlated and unstable, clinically interpretable measures such as winter temperature may provide practical support for risk assessment. Full article

Since current therapies cannot regenerate lost myocardium or reverse adverse ventricular remodeling—major contributors to worldwide cardiovascular mortality—advanced biomaterials, particularly hydrogels, have emerged as promising therapeutic platforms. Among these, bacterial nanocellulose (BNC) has gained increasing attention due to its hydrated nanofibrillar architecture, high crystallinity, robust mechanical performance, and excellent water-retention capacity, features that closely resemble key aspects of the native extracellular matrix. These properties provide a favorable microenvironment for cell adhesion, survival, and tissue organization in cardiovascular applications. Preclinical evidence suggests that BNC-based cardiac constructs, including acellular patches and cell-laden systems, may reduce post-infarction ventricular dilation, promote angiogenesis, and improve cellular engraftment. In vascular tissue engineering, BNC has also been explored in small-diameter grafts, anisotropic hydrogel systems, and shape-memory conduits with encouraging hemocompatibility and functional durability. Functional modifications—including gelatin incorporation, oxidative surface treatments, peptide grafting, conductive polymers, and structural alignment strategies—further expand the biological and mechanical versatility of BNC-based systems. In addition, BNC-containing bioinks have demonstrated promising rheological behavior, printability, and cell compatibility for 3D bioprinting applications. Despite these advances, important challenges remain, including optimization of material functionalization, host integration, degradation control, vascularization, scalable manufacturing, and regulatory translation toward clinical application. Full article

Background: Chronic hepatitis C virus (HCV) infection is increasingly recognized as a systemic inflammatory condition associated with accelerated atherosclerosis and adverse cardiovascular outcomes. However, its relationship with coronary anatomical complexity in patients presenting with ST-segment elevation myocardial infarction (STEMI) remains insufficiently defined. Aims: This study aimed to evaluate the association between chronic HCV infection and coronary artery disease complexity assessed by the SYNTAX score in STEMI patients undergoing primary percutaneous coronary intervention (pPCI) and to investigate its relationship with in-hospital mortality. Methods: In this retrospective single-center cohort study, 1647 STEMI patients treated with pPCI between January 2021 and December 2025 were analyzed; 106 (6.4%) were HCV-positive. Propensity score matching based on baseline demographic and cardiovascular risk factors yielded 105 matched pairs. The primary endpoint was the SYNTAX score, while the secondary endpoint was in-hospital all-cause mortality. Results: HCV-positive patients demonstrated significantly higher SYNTAX scores than HCV-negative patients before (19.5 ± 8.5 vs. 15.8 ± 9.6; p < 0.001) and after propensity score matching (19.4 ± 8.5 vs. 15.6 ± 9.2; p = 0.002). Coronary artery bypass grafting referral was more frequent among HCV-positive patients both before (11.3% vs. 5.3%; p = 0.010) and after matching (11.4% vs. 2.9%; p = 0.016). Notably, HCV-positive patients exhibited higher coronary anatomical complexity despite lower total and LDL cholesterol levels. In multivariable analyses, HCV positivity remained independently associated with higher SYNTAX scores in both unmatched and matched cohorts. In-hospital mortality rates were comparable between groups, and HCV positivity was not independently associated with mortality. Conclusions: Chronic HCV infection was independently associated with increased coronary anatomical complexity in STEMI patients undergoing pPCI, suggesting a relationship with a more diffuse and structurally complex atherosclerotic phenotype rather than short-term in-hospital outcomes. These findings support the concept of HCV infection as a non-traditional cardiovascular risk factor associated with adverse coronary vascular remodeling. Full article

Background/Objectives: Horizontal alveolar ridge resorption following tooth loss often compromises implant placement and requires augmentation procedures to restore adequate bone volume. This pilot case series descriptively evaluated the clinical, radiographic, and histological outcomes of lateral ridge augmentation (LRA) using a collagenated porcine-derived xenograft combined with autogenous bone. Methods: Three consecutive partially edentulous patients presenting with severe horizontal ridge deficiency (residual bone width ≤ 4 mm) underwent LRA using a mixture of porcine-derived xenograft and autogenous bone covered with a resorbable collagen membrane. After a healing period of 3–5 months, core biopsies were harvested at implant placement and subjected to histological and histomorphometric analysis, including TRAP staining. Results: All sites healed uneventfully without intraoperative or postoperative complications. Radiographic evaluation demonstrated substantial horizontal bone gain, allowing placement of standard-diameter implants. Histological analysis revealed newly formed trabecular bone, residual graft material, and well-vascularized connective tissue, indicating active bone regeneration and biomaterial integration. TRAP-positive multinucleated giant cells (MNGCs) were observed at the biomaterial interface, suggesting ongoing remodeling. Long-term follow-up (mean 54.2 months) showed stable implant function without biological or mechanical complications. Conclusions: Within the limitations of this pilot case series, LRA using a collagenated porcine-derived xenograft combined with autogenous bone demonstrated preliminary favorable clinical, radiographic, and histological outcomes. Full article