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Proliferation of vascular smooth muscle cells (vSMCs) is a crucial contributor to pathological vascular remodeling. MicroRNAs (miRNAs) are powerful gene regulators and attractive therapeutic agents. Here, we aimed to systematically identify and characterize miRNAs with therapeutic potential in targeting vSMC proliferation. Using high-throughput screening, we assessed the impact of 2,042 human miRNA mimics on vSMC proliferation and identified seven miRNAs with novel vSMC anti-proliferative function: miR-323a-3p, miR-449b-5p, miR-491-3p, miR-892b, miR-1827, miR-4774-3p, and miR-5681b. miRNA-mimic treatment affects proliferation of vSMCs from different vascular beds. Focusing on vein graft failure, where miRNA-based therapeutics can be applied to the graft ex vivo, we showed that these miRNAs reduced human saphenous vein smooth muscle cell (HSVSMC) proliferation without toxic effect. HSVSMC transcriptomics revealed a distinct set of targets for each miRNA, leading to the common downregulation of a cell-cycle gene network for all miRNAs. For miR-449b-5p, we showed that its candidate target, CCND1, contributes to HSVSMC proliferation. In contrast to HSVSMCs, miRNA overexpression in endothelial cells led to a limited response in terms of proliferation and transcriptomics. In an ex vivo vein organ model, overexpression of miR-323a-3p and miR-449b-5p reduced medial proliferation. Collectively, the results of our study show the therapeutic potential of seven miRNAs to target pathological vascular remodeling., Competing Interests: Declaration of interests The authors declare the following financial interests/personal relationships that may be considered potential competing interests: A.H.B., M.G., and S.Z. are named inventors on a patent application related to this work (PCT/GB2023/052170)., (Copyright © 2025 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: We aimed to investigate the relationship between advanced glycation end product (AGE) levels in patients with saphenous vein graft (SVG) failure and in patients without SVG failure., Subjects and Methods: In our study, 55 patients with a history of previous coronary artery bypass grafting (CABG) surgery, who subsequently underwent coronary angiography for any reason and were found to have either SVG occlusion or significant lesions, were included as study patients. Additionally, 55 patients who have had CABG surgery without SVG failure for at least 1 year served as the control group. AGE values of the patients were measured using the skin autofluorescence method., Results: In our study results, we observed a significant difference in AGE levels between the two groups of patients with similar demographic characteristics (SVG failure groups AGE 3.2 [2.8-3.6] vs. control groups AGE 2.4 [2.1-2.7] p < 0.001). In the receiver operating characteristic curve analysis, we determined the ability of AGE levels to detect SVG failure with an area under the curve of 0.869. We found that in patients with AGE >3, it could detect SVG failure with a sensitivity of 70.9% and a specificity of 87.3%., Conclusions: Our results demonstrate that AGE levels can predict SVG failure risk inexpensively, easily, and quickly., Objective: We aimed to investigate the relationship between advanced glycation end product (AGE) levels in patients with saphenous vein graft (SVG) failure and in patients without SVG failure., Subjects and Methods: In our study, 55 patients with a history of previous coronary artery bypass grafting (CABG) surgery, who subsequently underwent coronary angiography for any reason and were found to have either SVG occlusion or significant lesions, were included as study patients. Additionally, 55 patients who have had CABG surgery without SVG failure for at least 1 year served as the control group. AGE values of the patients were measured using the skin autofluorescence method., Results: In our study results, we observed a significant difference in AGE levels between the two groups of patients with similar demographic characteristics (SVG failure groups AGE 3.2 [2.8-3.6] vs. control groups AGE 2.4 [2.1-2.7] p < 0.001). In the receiver operating characteristic curve analysis, we determined the ability of AGE levels to detect SVG failure with an area under the curve of 0.869. We found that in patients with AGE >3, it could detect SVG failure with a sensitivity of 70.9% and a specificity of 87.3%., Conclusions: Our results demonstrate that AGE levels can predict SVG failure risk inexpensively, easily, and quickly., (© 2024 The Author(s). Published by S. Karger AG, Basel.)

Background: Chronic venous insufficiency (CVI) manifests as morphological and functional abnormalities in the venous system, primarily affecting the lower extremities and presenting as leg heaviness, oedema, and varicose veins. CVI is a common vascular disorder characterised by impaired blood flow in the veins, often leading to various clinical manifestations. To better understand the additional underlying mechanisms of CVI, it is essential to explore the role of Wnt proteins, which play a crucial role in regulating signalling processes. This study aimed to investigate the expression levels of the Wnt3a and Wnt5a genes using real-time PCR in patients with venous insufficiency compared to acontrol group., Methods and Results: 68 participants were included, comprising 29 controls and 39 patients with venous insufficiency from Near East University Hospital. Real-time PCR was utilised for gene expression analysis on a segment of the great saphenous vein biopsy, encompassing all vascular layers, from each participant in both groups. With a significance threshold of p < 0.05, the analysis revealed a significant difference in Wnt3a gene expression (p ₌ 0.0007) and a nonsignificant difference in Wnt5a expression levels (p ₌ 0.5726) between patients with venous insufficiency and the healthy control group., Conclusion: This study indicates fluctuations in the Wnt genes in varicose vein biopsies compared to healthy veins. Consequently, further research is essential to elucidate whether the dysregulation of the Wnt pathway induces venous insufficiency or vice versa. This may facilitate targeted interventions addressing its fundamental molecular aberrations., Competing Interests: Declarations. Ethics approval: The study adhered to the principles outlined in the World Medical Association Declaration of Helsinki and the ethical frameworks that regulate medical research involving human participants. Additionally, the Near East University Hospital (NEUH) and the ethical review board both approved it (Project No.: NEU/2022/108–1658). Consent to participate: All participants voluntarily agreed to participate after being fully informed about the study’s nature, and written informed consent was obtained from all patient and control participants prior to their involvement. Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Rationale: Elevated shear stress (ESS) induces vascular remodeling in veins exposed to arterial blood flow, which can lead to arteriovenous (AV) fistula failure. The molecular mechanisms driving remodeling have not been comprehensively examined with a single-cell resolution before. Objective: Using an in vivo animal mode, single-cell RNA sequencing, and histopathology, we precisely manipulate blood flow to comprehensively characterize all cell subpopulations important during vascular remodeling. Methods: AV loops were created in saphenous vessels of rats using a contralateral saphenous vein interposition graft to promote ESS. Saphenous veins with no elevated shear stress (NSS) were anastomosed as controls. Findings: ESS promoted transcriptional homogeneity, and NSS promoted considerable heterogeneity. Specifically, ESS endothelial cells (ECs) showed a more homogeneous transcriptional response promoting angiogenesis and upregulating endothelial-to-mesenchymal transition inhibiting genes ( Klf2 ). NSS ECs upregulated antiproliferation genes such as Cav1 , Cst3 , and Btg1 . In macrophages, ESS promoted a large homogeneous subpopulation, creating a mechanically activated, proinflammatory and thus proangiogenic myeloid phenotype, whereas NSS myeloid cells expressed the anti-inflammatory and antiangiogenetic marker Mrc1 . Conclusion: ESS activates unified gene expression profiles to induce adaption of the vessel wall to hemodynamic alterations. Targeted depletion of the identified cellular subpopulations may lead to novel therapies to prevent excessive venous remodeling, intimal hyperplasia, and AV fistula failure.

Venous graft decay (VGD) occurs in coronary artery bypass grafting (CABG), and ischemia-reperfusion oxidative stress injury during the operation is involved in VGD. To explore the cellular phenotypic changes during this process, a stable oxidative stress model of human saphenous vein endothelial cells (HSVECs) is constructed. Through proteomics and cell experiments, it is found that the expression of BCL2L13 is upregulated during oxidative stress of HSVECs, and BCL2L13 regulated mitophagy through receptor-mediated interaction with LC3 and plays a role in cell protection. During oxidative stress, intracellular o 8 G epigenetic modification occurs, and the o 8 G modification of miR-6513-5p causes this molecule to lose its targeted regulation of BCL2L13 and participates in the upregulation of BCL2L13. There is a regulatory pathway of o 8 G modification-BCL2L13-LC3-mitophagy when oxidative stress occurs in HSVECs., (© 2024 Wiley‐VCH GmbH.)

Vein graft disease is the process by which saphenous vein grafts, utilised for revascularisation during coronary artery bypass graft surgery, undergo an inflammation-driven intimal hyperplasia and accelerated atherosclerosis process in subsequent years after implantation. The role of the arterial circulation, particularly the haemodynamic properties' impact on graft patency, have been investigated but have not to date been explored in depth at the transcriptomic level. We have undertaken the first-in-man spatial transcriptomic analysis of the long saphenous vein in response to ex vivo acute arterial haemodynamic stimulation, utilising a combination of a custom 3D-printed perfusion bioreactor and the 10X Genomics Visium Spatial Gene Expression technology. We identify a total of 413 significant genes (372 upregulated and 41 downregulated) differentially expressed in response to arterial haemodynamic conditions. These genes were associated with pathways including NFkB , TNF , MAPK , and PI3K/Akt , among others. These are established pathways involved in the initiation of an early pro-inflammatory response, leukocyte activation and adhesion signalling, tissue remodelling, and cellular differentiation. Utilising unsupervised clustering analysis, we have been able to classify subsets of the expression based on cell type and with spatial resolution. These findings allow for further characterisation of the early saphenous vein graft transcriptional landscape during the earliest stage of implantation that contributes to vein graft disease, in particular validation of pathways and druggable targets that could contribute towards the therapeutic inhibition of processes underpinning vein graft disease.

Objective: Diabetes and hypertension are important risk factors for vascular disease, including atherosclerosis. A driving factor in this process is lipid accumulation in smooth muscle cells of the vascular wall. The glucose- and mechano-sensitive transcriptional coactivator, myocardin-related transcription factor A (MRTF-A/MKL1) can promote lipid accumulation in cultured human smooth muscle cells and contribute to the formation of smooth muscle-derived foam cells. The purpose of this study was to determine if intact human blood vessels ex vivo can be used to evaluate lipid accumulation in the vascular wall, and if this process is dependent on MRTF and/or galectin-3/LGALS3. Galectin-3 is an early marker of smooth muscle transdifferentiation and a potential mediator for foam cell formation and atherosclerosis., Approach and Results: Human mammary arteries and saphenous veins were exposed to altered cholesterol and glucose levels in an organ culture model. Accumulation of lipids, quantified by Oil Red O, was increased by cholesterol loading and elevated glucose concentrations. Pharmacological inhibition of MRTF with CCG-203971 decreased lipid accumulation, whereas adenoviral-mediated overexpression of MRTF-A had the opposite effect. Cholesterol-induced expression of galectin-3 was decreased after inhibition of MRTF. Importantly, pharmacological inhibition of galectin-3 with GB1107 reduced lipid accumulation in the vascular wall after cholesterol loading., Conclusion: Ex vivo organ culture of human arteries and veins can be used to evaluate lipid accumulation in the intact vascular wall, as well as adenoviral transduction and pharmacological inhibition. Although MRTF and galectin-3 may have beneficial, anti-inflammatory effects under certain circumstances, our results, which demonstrate a significant decrease in lipid accumulation, support further evaluation of MRTF- and galectin-3-inhibitors for therapeutic intervention against atherosclerotic vascular disease., Competing Interests: Declaration of competing interest The authors (MAM, JE, OH, OR and JH) declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. The author (SA) is an Editorial Board Member for Vascular Pharmacology and was not involved in the editorial review or the decision to publish this article. The authors (UN, FLZ, and HL) declare the following financial interests/personal relationships which may be considered as potential competing interests: The authors (UN, FLZ, and HL) are shareholders and consultants with Galecto Biotech AB, a company developing small molecule galectin inhibitors for treatments of fibrosis and cancer., (Copyright © 2023. Published by Elsevier Inc.)

To better understand mechanisms of serotonin- (5-HT) mediated vasorelaxation, isolated lateral saphenous veins from cattle were assessed for vasoactivity using myography in response to increasing concentrations of 5-HT or selective 5-HT receptor agonists. Vessels were pre-contracted with 1 × 10 -4  M phenylephrine and exposed to increasing concentrations of 5-HT or 5-HT receptor agonists that were selective for 5-HT 1B , 5-HT 2B , 5-HT 4 , and 5-HT 7 . Vasoactive response data were normalized as a percentage of the maximum contractile response induced by the phenylephrine pre-contraction. At 1 × 10 -7  M 5-HT, a relaxation was observed with an 88.7% decrease (p < 0.01) from the phenylephrine maximum. At 1 × 10 -4  M 5-HT, a contraction was observed with a 165% increase (p < 0.01) from the phenylephrine maximum. Increasing concentrations of agonists selective for 5-HT 2B , 5-HT 4 , or 5-HT 7 resulted in a 27%, 92%, or 44% (p < 0.01) decrease from the phenylephrine maximum, respectively. Of these 5-HT receptor agonists, the selective 5-HT 4 receptor agonist resulted in the greatest potency (-log EC 50 ) value (6.30) compared with 5-HT 2B and 5-HT 7 receptor agonists (4.21 and 4.66, respectively). To confirm the involvement of 5-HT 4 in 5-HT-mediated vasorelaxation, blood vessels were exposed to either DMSO (solvent control) or a selective 5-HT 4 antagonist (1 × 10 -5  M) for 5-min prior to the phenylephrine pre-contraction and 5-HT additions. Antagonism of the 5-HT 4 receptor attenuated the vasorelaxation caused by 5-HT. Approximately 94% of the vasorelaxation occurring in response to 5-HT could be accounted for through 5-HT 4 , providing strong evidence that 5-HT-mediated vasorelaxation occurs through 5-HT 4 activation in bovine peripheral vasculature., (© 2024 The Author(s). Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)

Background: Varicose veins affect approximately 25% of people in industrialized countries., Methods: The study aimed at detecting apoptotic cells and histopathological changes in varicose vein walls. Patients (N.=41) with varicose veins and 30 control group patients were divided into two groups according to their age (younger and older than 50 years). Apoptosis was determined by the TUNEL assay, elastin and collagen IV expression by immunohistochemistry and ultrastructural changes by transmission electron microscopy., Results: The results show that the number of apoptotic cells in the layers of varicose veins increased, in particular in a group of patients aged over 50 years. In the varicose veins as compared to control veins the elastic fibers were found to be thinner, more fragmented and disorderly arranged. Elastin and collagen IV expression was found to decline in the intima and the media of varicose veins in both age groups. Electron microscopy demonstrated hypertrophy and degeneration of smooth muscle cells. Furthermore, cells with ultrastructural feature of apoptosis were noted. In the disorganized and expanded extracellular matrix membrane-bound vesicles, ghost bodies with different size and electron density were observed. Ghost bodies seem to bud off from smooth muscle cells and are likely to be involved in extracellular matrix remodeling as they are seen in close contact with collagen fibers., Conclusions: The study demonstrates increase of apoptotic cells in the wall of varicose veins along with vein wall structural abnormalities including alterations of smooth muscle cells and decline of elastin and collagen IV expression.

Objective: The contribution of hypoxia to the pathophysiology of vascular smooth muscle cells (VSMCs) has not yet been fully elucidated. This study evaluated the effect of hypoxia on the phenotype and function of SMCs derived from the human normal great saphenous veins (NGSVs)., Methods: Fifteen NGSV tissue samples were collected. SMCs were isolated and cultured. Proliferation, migration, adhesion, senescence, and the structure of cytoskeletal filaments in SMCs were observed. mRNA and protein expression of Bax, Bcl-2, caspase-3, matrix metalloproteinases (MMP)-2, MMP-9, tissue inhibitor of metalloproteinases (TIMP)-1, and TIMP-2 was detected by fluorescent quantitative polymerase chain reaction and immunoblotting in the cobalt chloride (CoCl 2 ) and the control groups., Results: A decrease in the number of cytoskeletal filaments was observed. mRNA and protein expression of Bas and caspase-3 was significantly decreased, while the quantity of proliferation, migration, adhesion, senescence, and mRNA and protein expression of Bcl-2, MMP-2, MMP-9, TIMP-1, and TIMP-2 in SMCs in the CoCl 2 group were significantly increased compared with the control group., Conclusion: Under hypoxic conditions, the phenotype and function of SMCs derived from the human NGSVs were dysregulated, suggesting that VSMCs switch from the contractile phenotype to the secretory or synthetic phenotype, and more dedifferentiate, resulting in extracellular matrix deposition and apoptotic decrease through the intrinsic pathway., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Introduction: This study investigated the combination of venous stasis and inflammation in varicose vein development., Methods: The study included patients with primary varicose veins operated using high ligation and stripping of greater saphenous vein. All of them showed reflux at sapheno-femoral junction on preoperative Doppler ultrasound. Mesenteric veins from early or advanced gastric cancer specimens were used as control group. Inflammatory mediators expressed in the venous wall were measured via immunohistochemistry and compared between the two groups., Results: Thirty-five (59.3%) men and 24 women with a mean age of 52.8 years (range, 23-77 years) were included and 29 (49.2%) patients had edema or skin changes according to Clinical-Etiology-Anatomy-Pathophysiology (CEAP) classification and reporting standards for chronic venous disorders. The expression of interleukin 6 (IL-6) and transforming growth factor β1 (TGF-β1) in intima and those of IL-6 in media of greater saphenous veins increased, with statistically significant differences between the two groups (p &lt; 0.001). IL-6 in media and TGF-β1 levels in intima were independent predictors of varicose veins (adjusted odds ratios 74.62 and 66.69, respectively)., Conclusion: Elevated venous pressure represented by reflux on Doppler ultrasound and increased expression of inflammatory cytokines including IL-6 in media and TGF-β1 in intima are associated with the development of varicose veins., (© 2024 S. Karger AG, Basel.)

Vascular pathologies show locational predisposition throughout the body; further insights into the transcriptomics basis of this vascular heterogeneity are needed. We analyzed transcriptomes from cultured endothelial cells and vascular smooth muscle cells from nine adult canine macrovessels: the aorta, coronary artery, vena cava, portal vein, femoral artery, femoral vein, saphenous vein, pulmonary vein, and pulmonary artery. We observed that organ-specific expression patterns persist in vitro, indicating that these genes are not regulated by blood flow or surrounding cell types but are likely fixed in the epigenetic memory. We further demonstrated the preserved location-specific expression of GATA4 protein in cultured cells and in the primary adult vessel. On a functional level, arterial and venous endothelial cells differed in vascular network morphology as the arterial networks maintained a higher complexity. Our findings prompt the rethinking of the extrapolation of results from single-origin endothelial cell systems., (© 2023. Springer Nature Limited.)

Saphenous vein bypass grafting is an effective technique used to treat peripheral arterial disease (PAD). However, restenosis is the major clinical challenge for the graft vessel among people with PAD postoperation. We hypothesize that there is a common culprit behind arterial occlusion and graft restenosis. To investigate this hypothesis, we found TGF-β, a gene specifically upregulated in PAD arteries, by bioinformatics analysis. TGF-β has a wide range of biological activities and plays an important role in vascular remodeling. We discuss the molecular pathway of TGF-β and elucidate its mechanism in vascular remodeling and intimal hyperplasia, including EMT, extracellular matrix deposition, and fibrosis, which are the important pathways contributing to stenosis. Additionally, we present a case report of a patient with graft restenosis linked to the TGF-β pathway. Finally, we discuss the potential applications of targeting the TGF-β pathway in the clinic to improve the long-term patency of vein grafts.

Aims: The aim of this study was to investigate the effects of pioglitazone on reactive oxygen species (ROS), expressions/activities of MMPs and TIMP-2, and VSMC proliferation and vascular reactivity in high glucose (HG)-induced human saphenous vein (HSV) grafts., Methods: HSV grafts (n = 10) obtained from patients undergoing CABG were incubated with 30 mM glucose and/or 10 μM pioglitazone or 0.1 % DMSO for 24 h after endothelium removal. ROS levels were examined by chemiluminescence assay, MMP-2,-9,-14, TIMP-2, and α-SMA expression/activity was determined by gelatine zymography/immunohistochemistry. Vascular reactivity to potassium chloride, noradrenaline, serotonin, prostaglandin F 2α and papaverine was assessed in HSVs., Results: HG induced superoxide anion (SA) (123 %) and other ROS levels (159 %), up-regulated MMP-2 expression (180 %)/activity (79 %), MMP-14 expression (24 %) and MMP-9 activity while down-regulating TIMP-2 expression (27 %). HG elevated total MMP-2/TIMP-2 ratio (483 %) and MMP-14/TIMP-2 ratio (78 %). However, HG plus pioglitazone inhibited SA (30 %) and other ROS levels (29 %), down-regulated MMP-2 expression (76 %)/activity (83 %), MMP-14 expression (38 %) and MMP-9 activity, while reversing TIMP-2 expression (44 %). HG plus pioglitazone decreased total MMP-2/TIMP-2 ratio (91 %) and MMP-14/TIMP-2 ratio (59 %). HG impaired contractions to all agents but pioglitazone improved them., Conclusions: Pioglitazone may contribute to the prevention of restenosis and maintaining vascular function in HSV grafts of DM patients undergoing CABG., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interests., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Long noncoding RNAs (lncRNAs) have been widely suggested to bind with the microRNA (miRNA) sites and play roles of competing endogenous RNAs (ceRNAs), which can thus affect and regulate target gene and mRNA expression. Such lncRNA-related ceRNAs are identified to exert vital parts in vascular disease. Nonetheless, it remains unknown about how the lncRNA-miRNA-mRNA network functions in the varicose great saphenous veins., Methods: This study acquired the lncRNA and mRNA expression patterns from the GEO database and identifies the differentially expressed mRNAs and lncRNAs by adopting the R software "limma" package. Then, miRcode, miRDB, miRTarbase, and TargetScan were used to establish the miRNA-mRNA pairs and lncRNA-miRNA pairs. In addition, the lncRNA-miRNA-mRNA ceRNA network was constructed by using Cytoscape. Protein-protein interaction, Gene Ontology functional annotations, and Kyoto Encyclopedia of Genes and Genomes enrichment were carried out to examine the candidate hub genes, the functions of genes, and the corresponding pathways., Results: In line with the preset theory, we constructed ceRNA network comprising 12 lncRNAs, 38 miRNAs, and 149 mRNAs. Kyoto Encyclopedia of Genes and Genomes analysis indicated that the PI3K/Akt signaling pathway played a vital part in the development of varicose great saphenous veins. AC114730, AC002127, and AC073342 were significant biomarkers. At the same time, we predicted the potential miRNA, which may exert a significant influence on the varicose great saphenous veins, namely, miR-17-5p, miR-129-5p, miR-1297, miR-20b-5p, and miR-33a-3p., Conclusion: By performing ceRNA network analysis, our study detects new lncRNAs, miRNAs, and mRNAs, which can be applied as underlying biomarkers of varicose great saphenous veins and as therapeutic targets for the treatment of varicose great saphenous veins., Competing Interests: The authors declare that they have no competing interests., (Copyright © 2022 Jiabo Wei et al.)

Objective: We examined quantitative (in terms of mtDNA/nuclear DNA) and structural (in terms of common deletions in the MT-ND4 gene region) characteristics of mitochondrial DNA (mtDNA) in varicose veins (VVs) and venous wall layers by comparing mitochondrial genome parameters, as well as mitochondrial function (in terms of mitochondrial membrane potential (MtMP)), in varicose vein (VV) vs. non-varicose vein (NV) tissue samples., Methods: We analyzed paired great saphenous vein samples (VV vs. NV segments from each patient left after venous surgery) harvested from patients with VVs. Relative mtDNA level and the proportion of no-deletion mtDNA were determined by a multiplex quantitative PCR (qPCR), confirming the latter with a more sensitive method - droplet digital PCR (ddPCR). Mitochondria's functional state in VVs was assessed using fluorescent (dependent on MtMP) live-staining of mitochondria in venous tissues., Results: Total mtDNA level was lower in VV than in NV samples (predominantly in the t. media layer). ddPCR analysis showed lower proportion of no-deletion mtDNA in VVs. Because of the decrease in relative MtMP in VVs, our results suggest a possible reduction of mitochondrial function in VVs., Conclusion: Quantitative and structural changes (copy number and integrity) of mtDNA are plausibly involved in VV pathogenesis. Future clinical studies implementing the mitochondrial targeting may be eventually fostered after auxiliary mechanistic studies., Competing Interests: Declaration of Competing Interest The authors declare no competing interests., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Vasospasm and atherosclerosis due to low endothelial capacity are the most important causes of coronary artery bypass graft failure observed in internal mammary artery (IMA) and saphenous vein (SV). Vasospasm can be mimicked in in-vitro studies by inducing vasoconstriction of graft materials. In the present study, we aimed to compare the vascular contraction induced by several spasmogens including prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF2α), phenylephrine (PE), leukotriene C4 (LTC4), LTD4, potassium chloride (KCl), and arachidonic acid between IMA and SV preparations. Furthermore, endothelial capacity, nitrite and asymmetric dimethylarginine (ADMA) levels were compared between two grafts., Methods: By using organ bath, contractile responses induced by different spasmogens were compared between IMA and SV preparations derived from patients underwent coronary artery bypass surgery (N.=35). The endothelial capacity was determined by acetylcholine-induced (ACh) relaxation in PE-precontracted vessels. Nitrite and ADMA levels were measured in organ culture supernatant of IMA and SV preparations., Results: Contractile responses induced by PGE2, PGF2α, PE, LTC4, LTD4, KCl and arachidonic acid were significantly lower in IMA preparations versus SV preparations. ACh-induced relaxation was significantly more prominent in IMA than SV preparations. Nitrite levels were greater and ADMA levels were lower in IMA versus SV preparations., Conclusions: IMA has reduced capacity to constrict to several vasoconstrictor agents. Furthermore, IMA has greater endothelial capacity associated with higher nitrite levels and lower ADMA levels. Our results support the greater patency rate observed in IMA versus SV preparations.

Background: Superficial thrombophlebitis (ST) is a frequent pathology, but its exact incidence remains to be determined. This study tested the hypothesis whether relationships exist among smooth muscle cells (SMCs) derived from ST, varicose great saphenous veins (VGSVs), and normal great saphenous veins (GSVs)., Methods: Forty-one samples of ST, VGSVs, and GSVs were collected. SMCs were isolated and cultured. Proliferation, migration, adhesion, and senescence in SMCs from the three vein walls were compared by various methods. Bax, Bcl-2, caspase-3, matrix metalloproteinase-2 (MMP-2), MMP-9, tissue inhibitor of metalloproteinase-1 (TIMP-1), and TIMP-2 messenger RNA (mRNA) and protein expressions were detected by fluorescence quantitative PCR and Western blot., Results: An obvious decrease in cytoskeletal filaments was observed in thrombophlebitic vascular smooth muscle cells (TVSMCs). The quantity of proliferation, migration, adhesion, and senescence in TVSMCs was significantly higher than in varicose vascular smooth muscle cells and normal vascular smooth muscle cells (NVSMCs) (all P < 0.05). Bax and caspase-3 mRNA and protein expression were decreased, while Bcl-2 mRNA and protein expression were increased in the TVSMCs compared with the varicose vascular smooth muscle cells and the NVSMCs (all P < 0.05). MMP-2, MMP-9, TIMP-1, and TIMP-2 mRNA and protein expression were significantly increased in the TVSMCs compared with the VVGSVs and the NVSMCs (all P < 0.05)., Conclusion: SMCs derived from ST are more dedifferentiated and demonstrate increased cell proliferation, migration, adhesion, and senescence, as well as obviously decreased cytoskeletal filaments. These results suggest that the phenotypic and functional differences could be related to the presence of atrophic and hypertrophic vein segments during the disease course among SMCs derived from ST, VGSVs, and GSVs., (Copyright © 2021. Published by Elsevier Inc.)

Atherosclerosis is one of the leading non-communicable diseases in Sri Lanka. Analysis of fatty acid composition in blood vessels is important in understanding the development of atherosclerosis. Here, analyses of fatty acid profiles in major arteries which are commonly used in Coronary Artery Bypass Graft surgery (CABG) were subjected to investigation. Patients (n = 27) undergoing elective CABG were enrolled in the study. A small biopsy segment of the saphenous vein (SV), radial artery (RA), and left internal mammary artery (LIMA) of patients was obtained during the surgery. The fatty acid (FA) profile of tissue samples was analyzed using Gas Chromatography-Mass Spectroscopy (GCMS). Among the different arteries tested, palmitic acid and stearic acid were the predominant fatty acids. As far as monounsaturated FA (MUFA) are concerned, oleic acid was found to be the most abundant MUFA in vessels. The FA profile of LIMA samples had a higher SFA percentage and lower unsaturated FA percentage compared to other vessels. Furthermore, the vessel samples of RA indicated the highest percentage of pro-inflammatory ω -6 polyunsaturated fatty acids (PUFA) as well as a higher percentage ratio between ω -6: ω -3 PUFA. The fatty acid composition and ω -6: ω -3 PUFA ratio suggests that LIMA graft is preferred for CABG over RA and SV., Competing Interests: The authors have declared that no competing interests exist.

Aims: Thromboxane (TxA 2 ) is synthesized from arachidonic acid (AA) via thromboxane synthase (TxS) enzyme and induces vasoconstriction via TP receptor. Our aim is to compare the effects of aspirin, TxS inhibitor and TP receptor antagonist on vascular reactivity of bypass grafts (saphenous vein and internal mammary artery)., Main Methods: Using isolated organ bath, saphenous vein and internal mammary artery preparations were incubated with TP receptor antagonist, TxS inhibitor, aspirin, IP or EP4 receptor antagonist. Then prostaglandin (PG)E 2 , PGF 2α , phenylephrine and AA were administered in concentration-dependent manner. The expression of prostanoid receptor and PGI 2 synthase (PGIS) enzyme was determined by Western Blot., Key Findings: TP receptor antagonist inhibited the contraction induced by PGE 2 , PGF 2α , and AA but not that induced by phenylephrine in both types of vessels. Aspirin increased phenylephrine-induced contraction only in internal mammary artery and decreased AA-induced contraction in saphenous vein. TxS inhibitor decreased both PGE 2 and AA-induced contraction in both types of vessels. This decrease was reversed by co-incubation of TxS inhibitor and IP/EP4 receptor antagonists. The expressions of EP3 receptor and PGIS enzyme were greater in internal mammary artery compared to saphenous vein while IP and TP receptors expressed at similar levels., Significance: TP receptor antagonist and TxS inhibitor are more effective to reduce contraction induced by different spasmogens in comparison to aspirin. Our results suggest that TP receptor antagonist and TxS inhibitor might have an advantage over aspirin due to their preventive effect on increased vascular reactivity observed in post-operative period of coronary artery bypass grafting., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Varicose veins are among the most common disorders of the vascular system; however, the pathogenesis of varicose veins remains unclear. The present study aimed to investigate the roles of microRNA (miR)‑199a‑5p in varicose veins and in the phenotypic transition of vascular smooth muscle cells (VSMCs). Bioinformatics analysis confirmed that miR‑199a‑5p had target sites on the forkhead box C2 (FOXC2) 3'‑untranslated region. Reverse transcription‑quantitative PCR (RT‑qPCR) and western blotting were used to detect the expression levels of miR‑199a‑5p and FOXC2 in varicose vein and normal great saphenous vein tissues. Cell Counting Kit‑8 and Transwell migration assays were performed to validate the effects of miR‑199a‑5p on VSMCs. Contractile markers, such as smooth muscle 22α, calponin, smooth muscle actin and myosin heavy chain 11 were used to detect phenotypic transition. RT‑qPCR revealed that miR‑199a‑5p was downregulated in varicose veins compared with expression in normal great saphenous veins, whereas FOXC2 was upregulated in varicose veins. In addition, biomarkers of the VSMC contractile phenotype were downregulated in varicose veins. Overexpression of miR‑199a‑5p by mimics suppressed VSMC proliferation and migration, whereas depletion of miR‑199a‑5p enhanced VSMC proliferation and migration. Notably, the effects caused by miR‑199a‑5p could be reversed by FOXC2 overexpression. Dual luciferase reporter analysis confirmed that FOXC2 was a target of miR‑199a‑5p. In conclusion, miR‑199a‑5p may be a novel regulator of phenotypic switching in VSMCs by targeting FOXC2 during varicose vein formation.

Chronic venous insufficiency (CVI), in which blood return to the heart is impaired, is a prevalent condition worldwide. Valve incompetence is a complication of CVI that results in blood reflux, thereby aggravating venous hypertension. While CVI has a complex course and is known to produce alterations in the vein wall, the underlying pathological mechanisms remain unclear. This study examined the presence of DNA damage, pro-inflammatory cytokines and extracellular matrix remodelling in CVI-related valve incompetence. One hundred and ten patients with CVI were reviewed and divided into four groups according to age (<50 and ≥50 years) and a clinical diagnosis of venous reflux indicating venous system valve incompetence (R) (n = 81) or no reflux (NR) (n = 29). In vein specimens (greater saphenous vein) from each group, PARP, IL-17, COL-I, COL-III, MMP-2 and TIMP-2 expression levels were determined by RT-qPCR and immunohistochemistry. The younger patients with valve incompetence showed significantly higher PARP, IL-17, COL-I, COL-III, MMP-2 and reduced TIMP-2 expression levels and a higher COL-I/III ratio. Young CVI patients with venous reflux suffer chronic DNA damage, with consequences at both the local tissue and systemic levels, possibly associated with ageing., (© 2021 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

The rate of the remodeling of the arterialized saphenous vein conduit limits the outcomes of coronary artery bypass graft surgery (CABG), which may be influenced by endothelial dysfunction. We tested the hypothesis that high stretch (HS) induces human saphenous vein endothelial cell (hSVEC) dysfunction and examined candidate underlying mechanisms. Our results showed that in vitro HS reduces NO bioavailability, increases inflammatory adhesion molecule expression (E-selectin and VCAM1) and THP-1 cell adhesion. HS decreases F-actin in hSVECs, but not in human arterial endothelial cells, and is accompanied by G-actin and cofilin's nuclear shuttling and increased reactive oxidative species (ROS). Pre-treatment with the broad-acting antioxidant N-acetylcysteine (NAC) supported this observation and diminished stretch-induced actin remodeling and inflammatory adhesive molecule expression. Altogether, we provide evidence that increased oxidative stress and actin cytoskeleton remodeling play a role in HS-induced saphenous vein endothelial cell dysfunction, which may contribute to predisposing saphenous vein graft to failure.

Introduction: Several treatment modalities have been postulated to improve the efficacy of varicose vein treatment. Addition of glycerine to the sclerosing material has been documented to increase its viscosity and subsequently prolong the duration of stability, in addition to the direct sclerosing effect of glycerine. This histological and immunohistochemical study investigated the efficacy of addition of glycerine 72% to sclerotherapy on the human varicose vein., Methods: After surgical stripping of great saphenous veins, three equal segments were resected between two clamps. Specimen 1 was injected with saline only, specimen 2 was exposed to foam sclerosant 2%, and specimen 3 was exposed to a mixture of foam sclerosant 2% and glycerine 72%. All segments were left for 5min. Vein segments were then processed for histological and immunohistochemical study., Results: Microscopically, haematoxylin and eosin-stained specimen 1 showed endothelial swelling, cytoplasmic eosinophilia and pyknotic nuclei. The media showed sarcoplasm vacuolisation and necrosis. Specimen 3 showed hypereosinophilic sarcoplasm of the smooth muscle fibres. Oedema was less evident, with a relative decrease in the thickness of the wall compared with specimen 2. Immunohistochemically, the expression of smooth muscle actin was weak in specimen 3 compared with specimens 1 and 2. Expression of CD31 antibody was much reduced in specimen 2 which showed conserved islands of endothelial cells. By contrast, there was a complete loss of endothelial cells in specimen 3., Conclusion: Addition of glycerine 72% to foam sclerosant has a more damaging effect on human vein wall.

Aim: Coronary artery bypass graft (CABG) using autologous saphenous vein continues to be a gold standard procedure to restore the supply of oxygen-rich blood to the heart muscles in coronary artery disease (CAD) patients with or without type 2 diabetes mellitus (T2DM). However, CAD patients with T2DM are at higher risk of graft failure. While failure rates have been reduced through improvements in procedure-related factors, much less is known about the molecular and cellular mechanisms by which T2DM initiates vein graft failure. This review gives novel insights into these cellular and molecular mechanisms and identifies potential therapeutic targets for development of new medicines to improve vein graft patency., Data Synthesis: One important cellular process that has been implicated in the pathogenesis of T2DM is protein O-GlcNAcylation, a dynamic, reversible post-translational modification of serine and threonine residues on target proteins that is controlled by two enzymes: O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). Protein O-GlcNAcylation impacts a range of cellular processes, including trafficking, metabolism, inflammation and cytoskeletal organisation. Altered O-GlcNAcylation homeostasis have, therefore, been linked to a range of human pathologies with a metabolic component, including T2DM., Conclusion: We propose that protein O-GlcNAcylation alters vascular smooth muscle and endothelial cell function through modification of specific protein targets which contribute to the vascular re-modelling responsible for saphenous vein graft failure in T2DM., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2021 The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.)

Objectives: We examined the expression, distribution, and contribution to vasodilatation of the calcium-activated potassium (K Ca ) channel family in the commonly used coronary artery bypass graft internal thoracic artery (ITA) and saphenous vein (SV) to understand the role of large conductance K Ca (BK Ca ), intermediate-conductance K Ca (IK Ca ), and small-conductance K Ca (SK Ca ) channel subtypes in graft dilating properties determined by endothelium-smooth muscle interaction that is essential to the postoperative performance of the graft., Methods: Real-time polymerase chain reaction and western blot were employed to detect the messenger RNA and protein level of K Ca channel subtypes. Distribution of K Ca channel subtypes was examined by immunohistochemistry. K Ca subtype-mediated vasorelaxation was studied using wire myography., Results: Both ITA and SV express all K Ca channel subtypes with each subtype distributed in both endothelium and smooth muscle. ITA and SV do not differ in the overall expression level of each K Ca channel subtype, corresponding to comparable relaxant responses to respective subtype activators. In ITA, BK Ca is more abundantly expressed in smooth muscle than in endothelium, whereas SK Ca exhibits more abundance in the endothelium. In comparison, SV shows even distribution of K Ca channel subtypes in the 2 layers. The BK Ca subtype in the K Ca family plays a significant role in vasodilatation of ITA, whereas its contribution in SV is quite limited., Conclusions: K Ca family is abundantly expressed in ITA and SV. There are differences between these 2 grafts in the abundance of K Ca channel subtypes in the endothelium and the smooth muscle. The significance of the BK Ca subtype in vasodilatation of ITA may suggest the potential of development of BK Ca modulators for the prevention and treatment of ITA spasm during/after coronary artery bypass graft surgery., (Copyright © 2019 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Chronic venous insufficiency (CVI) is a common disorder associated with a variety of symptoms in later disease stages; despite the high prevalence of this pathology, suitable pharmaceutical therapies have not been explored to date. In this context, it was recently reported that a chronic increase in venous wall stress or biomechanical stretch is sufficient to cause development of varicose veins. Recent evidence demonstrate that flavonoids are natural substances that convey the circulatory system functionality, playing a key role in blood flow. Particularly, troxerutin, diosmin and horse chestnut extract, appear protective for the management of vascular diseases. The aim of the present study was to evaluate the effect of a flavonoid compound, containing troxerutin, diosmin and horse chestnut extract on in vitro model on HUVECs cells, due to its production of vasculoregulatory and vasculotropic molecules, on an ex-vivo model on mesenteric vessel contraction, to regularize mesenteric microcirculation and on in vivo model of CVI-induced by saphene vein ligation. Furthermore, the flavonoid compound capacity of extensibility and compatibility with peripheral veins was investigated through a tissue block culture study. The degree of absorption, the contractile venous activity, the histological analysis, the immunoistochemical and immunofluorescence evaluation for VEGF and CD34 were performed, together with inflammatory mediators dosage. For the first time, this research revealed the therapeutic potential of a compound, enriched with flavonoids, to be a supportive treatment, suitable to reduce varicose vein pathophysiology and to regularize venous tone., (Copyright © 2020. Published by Elsevier Inc.)

Objective: The objective of this study was to analyze whether compression stocking therapy in the human varicose vein wall may change the levels of biomarkers associated with vein insufficiency., Methods: Dilated collateral varicose vein samples were obtained from patients showing chronic venous disease (class 2 of the Clinical, Etiology, Anatomy, and Pathophysiology classification). Before elective surgery, 12 patients underwent compression stocking therapy (for 1 month) and 9 patients did not (control group). Expression levels of biomarkers associated with endothelial functionality (nitric oxide synthase 3), inflammation (interleukin-6, interleukin-10), oxidative stress (Gp91 phox subunit of NADPH oxidase), and coagulation (factor Xa) were determined. P-selectin, an inflammatory and thrombosis-related biomarker, was also measured., Results: Compression stockings increased the content of nitric oxide synthase 3 (control, 16.48 [16.04-17.40] AU; compression, 83.71 [67.70-91.85] AU; P < .001) in the varicose vein wall that was accompanied by reduction of both interleukin-6 levels (control, 38.72 [33.48-48.52] pg/μg protein; compression, 14.49 [11.05-17.41] pg/μg protein; P = .001) and the expression of Gp91 phox subunit of NADPH oxidase (control, 63.24 [53.79-77.03] AU; compression, 36.85 [35.66-52.27] AU; P < .010). P-selectin (control, 77.37 [61.86-85.00] AU; compression, 54.31 [49.60-67.50] AU; P = .017) and factor Xa (control, 90.78 [75.02-100.00] AU; compression, 14.50 [13.77-36.20] AU; P < .001) were also reduced in the varicose vein wall of compression stocking-treated patients. However, P-selectin lost its statistical significance after adjustment by dyslipidemia., Conclusions: In the varicose vein wall, compression stocking therapy improved the content levels of biomarkers associated with endothelial functionality, inflammation, oxidative stress, and coagulation., (Copyright © 2020 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Chronic venous disease (CVeD) has a remarkable prevalence, with an estimated annual incidence of 2%. It has been demonstrated how the loss of homeostatic mechanisms in the vein wall can take part in the physiopathology of CVeD. In this regard, it has been described how different axis, such as IGF-1/PAPP-A/STC-2 axis, may play an essential role in tissue homeostasis. The aim of this research is to study both genetic and protein expressions of the IGF-1/PAPP-A/STC-2 axis in CVeD patients. It is a cross-sectional study in which genetic (RT-qPCR) and protein (immunohistochemistry) expression analysis techniques were accomplished in saphenous veins from CVeD patients ( n = 35) in comparison to individuals without vascular pathology (HV). Results show a significant increase in both genetic and protein expressions of PAPP-A and IGF-1, and a decrement STC-2 expression at the same time in CVeD patients. Our study is a pioneer for demonstrating that the expression of the different components of the IGF-1/PAPP-A/STC-2 axis is altered in CVeD patients. This fact can be a part of the loss of homeostatic mechanisms of the venous tissue. Further research should be destined to deepen into alterations of this axis, as well as to evaluate the usage of these components as therapeutic targets for CVeD., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2020 Miguel A. Ortega et al.)

Despite the high prevalence of varicose veins, the underlying pathogenesis of this disease remains unclear. The present study aims to explore the role of insulin-like growth factor binding protein 6 (IGFBP6) in vascular smooth muscle cells (VSMCs). Using a protein array approach, we identified several differentially expressed proteins between varicose great saphenous veins and normal great saphenous veins. Bioinformatic analysis showed that IGFBP6 was closely related to cell proliferation. Further validation confirmed that IGFBP6 was one of the most highly expressed proteins in varicose vein tissue. Knocking down IGFBP6 in VSMCs significantly attenuated cell proliferation and induced the S phase arrest during the cell cycle. Further experiments demonstrated that IGFBP6 knockdown increased cyclin E ubiquitination, which reduced expression of cyclin E and phosphorylation of CDK2. Furthermore, IGFBP6 knockdown arrested centrosome replication, which subsequently influenced VSMC morphology. Ultimately, IGFBP6 was validated to be involved in VSMC proliferation in varicose vein tissues. The present study reveals that IGFBP6 is closely correlated with VSMC biological function and provides unprecedented insights into the underlying pathogenesis of varicose veins., (© 2020 Wiley Periodicals LLC.)

Saphenous vein (SV) is one of the most widely used graft material in patients undergoing coronary artery bypass graft surgery (CABG). Thromboxane A 2 (TXA 2 ) is implicated in graft failure by inducing vasoconstriction and platelet aggregation. The aim of this study is to investigate the mechanism involved in TXA 2 -induced vasoconstriction in human SV. The role of different inhibitors and blockers on U46619 (TXA 2 -mimetic)-induced vasoconstriction is investigated by using an isolated organ bath system. Relaxation responses to several mediators are evaluated in SV pre-contracted with U46619 and compared with those pre-contracted with phenylephrine. Our results demonstrate that U46619-induced contraction is completely blocked by myosin light chain kinase inhibitor ML-9 or TP receptor antagonist BAY u3405. Furthermore, U46619-induced contraction is partially inhibited by phospholipase C inhibitor U73122, protein kinase C inhibitor calphostin C, Rho-kinase inhibitor Y-27632, L-type calcium channel blocker nifedipine, store-operated channel inhibitor SKF96365 or removal of extracellular calcium. Relaxation responses to NO donor (sodium nitroprusside), guanylate cyclase (GC) stimulator (riociguat), phosphodiesterase (PDE) inhibitors (sildenafil, IBMX), adenylate cyclase (AC) activator (forskolin) and acetylcholine (ACh) are markedly reduced when U46619 is used as a pre-contraction agent. Our results demonstrate that influx of extracellular Ca 2+ (through L-type calcium channels and store-operated calcium channels) and intracellular Ca 2+ release together with Ca 2+ sensitization (through Rho-kinase activation) are necessary components for TXA 2 -induced vasoconstriction in SV. Moreover, more pronounced decrease in vasorelaxation induced by several mediators (SNP, riociguat, sildenafil, IBMX, forskolin, and ACh) in the presence of U46619 when compared with phenylephrine suggests that there is a crosstalk between the TP receptor signaling pathway and PDE, AC, GC enzymes. We believe that the investigation of mechanism of the TXA 2 -induced vasoconstriction in SV will provide additional information for the prevention of SV graft failure., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Despite commonly used for coronary artery bypass surgery, saphenous vein (SV) grafts have significantly lower patency rates in comparison to internal thoracic artery (ITA) grafts, which might be due to the structural characteristics of the vessel wall but also due to differences in oxidative stress adaptation and molecular signaling and regulation. This human post mortem study included a total of 150 human bypass grafts (75 SV grafts and 75 ITA grafts) obtained from 60 patients divided into five groups due to the time period of implantation: group 1: baseline group without grafting; group 2: 1 day; group 3: > 1 day-1 week; group 4: > 1 week-1 month; group 5: > 1 month-1 year. Pieces of 3 mm length were fixed with formaldehyde, dehydrated, wax embedded, cut into sections of 3 µm thickness, and histologically and immunohistochemically examined. Over the whole time period, we observed a lower neointima formation and a better preserved media in ITA grafts with a higher percentage of TNF-α, PDGFR-α, and VEGF-A in nearly all vessel wall layers, a higher amount of MMP-7, MMP-9, EGFR, and bFGF positive cells in SV grafts and a timely different peak not only between ITA and SV grafts but also within the various vessel wall layers of both graft types. Since most of the examined growth factors, growth factor receptors and cytokines are regulated by MAPKs, our results suggest an activation of different pathways in both vessel graft types immediately after bypass grafting.

Background: The spiral saphenous vein graft is an excellent choice for venous reconstruction after periphery vein injury, but only few cases have been reported. We implanted a segment of a single saphenous vein into both the popliteal vein as a venous vein graft and into the popliteal artery as an arterial vein graft at the same time in a trauma patient; we then had an extraordinary opportunity to harvest and examine both patent venous and arterial vein grafts at 2 weeks after implantation., Methods: A spiral saphenous vein graft was made as previously described and implanted into the popliteal vein and artery as interposition grafts; because of the patient's serious injuries, an amputation was performed at day 18 after vascular reconstruction. The grafts were harvested, fixed, and examined using histology and immunohistochemistry., Results: Both grafts were patent, and there was a larger neointimal area in the venous graft compared to the arterial graft. There were CD31- and vWF-positive cells on both neointimal endothelia, with subendothelial deposition of α-actin-, CD3-, CD45-, and CD68-positive cells. There were fewer cells in the venous graft neointima compared to the arterial graft neointima; however, there were more inflammatory cells in the neointima of the venous graft. Some of the neointimal cells were PCNA-positive, whereas very few cells were cleaved caspase-3 positive. The venous graft neointimal endothelial cells were Eph-B4 and COUP-TFII positive, while the arterial graft neointimal endothelial cells were dll-4 and Ephrin-B2 positive., Conclusions: The spiral saphenous vein graft remains a reasonable choice for vessel reconstruction, especially in the presence of diameter mismatch. Both the venous and arterial grafts showed similar re-endothelialization and cellular deposition; the venous graft had more neointimal hyperplasia and inflammation. At an early time, endothelial cells showed venous identity in the venous graft, whereas endothelial cells showed arterial identity in the arterial graft., Clinical Relevance: Veins can be used as venous or arterial vein grafts but venous grafts have more neointimal hyperplasia and inflammation; vein grafts acquire different vessel identity depending on the environment into which they are implanted., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The long saphenous vein (LSV) is commonly used as a conduit in coronary artery bypass grafting. However, long term patency remains limited by the development of vascular inflammation, intimal hyperplasia and accelerated atherosclerosis. The impact of acute exposure of venous endothelial cells (ECs) to acute arterial wall shear stress (WSS) in the arterial circulation, and the subsequent activation of inflammatory pathways, remain poorly defined. Here, we tested the hypothesis that acute exposure of venous ECs to high shear stress is associated with inflammatory responses that are regulated by NF-κB both in-vitro and ex-vivo. Analysis of the LSV endothelium revealed that activation of NF-κB occurred within 30 min after exposure to arterial rates of shear stress. Activation of NF-κB was associated with increased levels of CCL2 production and enhanced binding of monocytes in LSVECs exposed to 6 h acute arterial WSS. Consistent with this, ex vivo exposure of LSVs to acute arterial WSS promoted monocyte interactions with the vessel lumen. Inhibition of the NF-κB pathway prevented acute arterial WSS-induced CCL2 production and reduced monocyte adhesion, both in vitro and in human LSV ex vivo, demonstrating that this pathway is necessary for the induction of the acute arterial WSS-induced pro-inflammatory response. We have identified NF-κB as a critical regulator of acute endothelial inflammation in saphenous vein in response to acute arterial WSS. Localised endothelial-specific inhibition of the NF-κB pathway may be beneficial to prevent vein graft inflammation and consequent failure.

Hemostasis is the normal process that produces a blood clot at a site of vascular injury. Mice are widely used to study hemostasis and abnormalities of blood coagulation because their hemostatic system is similar in most respects to that of humans, and their genomes can be easily manipulated to create models of inherited human coagulation disorders. Two of the most widely used techniques for assessing hemostasis in mice are the tail bleeding time (TBT) and saphenous vein bleeding (SVB) models. Here we discuss the use of these methods in the evaluation of hemostasis, and the advantages and limits of using mice as surrogates for studying hemostasis in humans.

Chronic venous disease (CVD) is the most common reported chronic condition in the United States, affecting more than 25 million Americans. Regardless of its high occurrence, current therapeutic options are far from ideal due to their palliative nature. For best treatment outcomes, challenging cases of chronic venous insufficiency (CVI) are treated by repair or replacement of venous valves. Regrettably, the success of venous valve transplant is dependent on the availability of autologous venous valves and hindered by the possibility of donor site complications and increased patient morbidity. Therefore, the use of alternative tissue sources to provide off-the-shelf venous valve replacements has potential to be extremely beneficial to the field of CVI. This manuscript demonstrates the capability of producing off-the-shelf fully functional venous valved extracellular matrix (ECM) scaffold conduits from bovine saphenous vein (SV), using an antigen removal (AR) method. AR ECM scaffolds maintained native SV structure-function relationships and associated venous valves function. Conversely, SDS decellularization caused significant changes to the collagen and elastin macromolecular structures, resulting in collagen fibril merging, elimination of fibril crimp, amalgaming collagen fibers and fragmentation of the inner elastic lamina. ECM changes induced by SDS decellularization resulted in significant venous valve dysfunction. Venous valved conduits generated using the AR approach have potential to serve as off-the-shelf venous valve replacements for CVI. STATEMENT OF SIGNIFICANCE: Retention of the structure and composition of extracellular matrix (ECM) proteins within xenogeneic scaffolds for tissue engineering is of crucial importance, due to the undeniable effect ECM proteins can impose on repopulating cells and function of the resultant biomaterial. This manuscript demonstrates that alteration or elimination of ECM proteins via commonly utilized decellularization approach results in complete disruption of venous valve function. Conversely, retention of the delicate ECM structure and composition of native venous tissue, using an antigen removal tissue processing method, results in preservation of native venous valve function., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020. Published by Elsevier Ltd.)

The long-term patency rate of saphenous vein (SV) grafts is poor compared to arterial grafts. To investigate the effects of surgical preparation (distention) of SV on hydrogen sulfide (H 2 S) released from the endothelium, human SV segments were harvested from 43 patients during coronary artery bypass surgery (CABG). Acetylcholine (ACh) induced relaxation that was inhibited by N G -nitro-L-arginine + indomethacin and cysteine aminotransferase inhibitor aminooxyacetic acid in the normal SV. In contrast, ACh did not evoke relaxation in the distended SV (DSV). The concentration of H 2 S quantified by methylene blue assay in DSV was significantly lower than that in control. Transmission electron microscope and immunohistochemistry studies showed that the preparation destroyed the endothelium, smooth muscle, organelle, and vasa vasorum. We conclude that surgical preparation injures the endothelium and smooth muscle of the SV grafts and reduces H 2 S release from SV. These effects may contribute to the poor long-term patency of the SV graft.

Coronary artery disease (CAD) remains one of the most important causes of morbidity and mortality worldwide, and the availability of percutaneous or surgical revascularization procedures significantly improves survival. However, both strategies are daunted by complications which limit long-term effectiveness. In-stent restenosis (ISR) is a major drawback for intracoronary stenting, while graft failure is the limiting factor for coronary artery bypass graft surgery (CABG), especially using veins. Conversely, internal thoracic artery (ITA) is known to maintain long-term patency in CABG. Understanding the biology and pathophysiology of ISR and vein graft failure (VGF) and mechanisms behind ITA resistance to failure is crucial to combat these complications in CAD treatment. This review intends to provide an overview of the biological mechanisms underlying stent and VGF and of the potential therapeutic strategy to prevent these complications. Interestingly, despite being different modalities of revascularization, mechanisms of failure of stent and saphenous vein grafts are very similar from the biological standpoint., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

Females have increase in-hospital mortality and poorer outcomes following coronary artery bypass grafting (CABG). Biological differences in the reactivity of the graft conduits to circulating catecholamine may contribute to this sex difference. This study examined sex differences in the vasoconstrictor responses of internal mammary artery (IMA) and saphenous vein (SV) conduits to phenylephrine (PE) and endothelin-1 (ET-1). Functional IMA and SV were obtained from 78 male and 50 female patients undergoing CABG (67.7 ± 11 and 69 ± 10 years, respectively) and subjected to the following experimental conditions. (1) Concentration response curves for PE and ET-1 were generated in an intact IMA and SV and endothelium denuded IMA segments, (2) in the presence of the nitric oxide synthase inhibitor (L-NAME) or the cyclooxygenase inhibitor (indomethacin) in an endothelium-intact IMA and (3) the activity state (abundance and phosphorylation) of the α 1 -adrenergic receptor was investigated using Phos-tag™ western blot analysis. (1) Compared to male, female IMA and SV were hypersensitive to PE but not ET-1 (p < 0.05). The female IMA hypersensitivity response to PE was abolished following endothelial denudation, (2) persisted in the presence of L-NAME but was abolished in the presence of indomethacin and (3) there was no sex differences in the abundance and phosphorylation of the α 1 -adrenergic receptor in IMA. Female IMA and SV graft conduits are hypersensitive to α 1 -adrenergic stimuli. This endothelial cyclooxygenase pathway-mediated hypersensitivity may produce excessive IMA and SV graft constriction in females administered catecholamines and could contribute to their poorer CABG outcomes.

Recent findings have suggested that the primary factors for development of chronic venous disease (CVD), which commonly manifests as varicose veins (VV), are due to structural and biochemical modifications of the vessel wall. The aim of this exploratory study was to characterize by flow cytometry the endothelial cells (EC) mechanically extracted from the varicose saphenous veins (VSV) segments of patients submitted to VV surgery, and to compare the expression of cell surface molecules in these EC with that observed in the EC from the graft SV (GSV) of patients undergoing bypass surgery. EC were isolated from distal- (varicose trunk) and from proximal- (nearly normal) VSV segments of 30 patients submitted to VV surgery, and from proximal GSV segments of 20 patients submitted to bypass surgery (control group), using a mechanical method, and their immunophenotype was characterized by flow cytometry. EC were identified as being CD45 neg CD146 bright CD31 bright , and analyzed for expression of activation-related (CD54, CD62E, CD106), procoagulant (CD142), and cell junction (CD31, CD146) molecules, and for the scavenger receptor, CD36. The EC harvested from the SV segments of CVD patients had lower expression of all the molecules evaluated, in comparison to controls; these differences were more evident for the EC isolated from the distal-VSV. The EC extracted from the proximal- and distal-VSV segments of the CVD patients also differ from each other, the first having lower levels of CD62E, CD106, CD142 and CD36. Groups did not match for gender and controls were heterogeneous concerning the underlying pathologies, which may have a confounding effect. Our study revealed that the EC isolated from varicose (distal) and nearly normal (proximal) VSV segments of the CVD patients differ phenotypically from each other, and from the EC of the control group. The VSV segments more affected by the CVD have the lowest expression of the studied markers. We hypothesize that CVD is associated with a decrease on the EC surface molecules, causing EC dysfunctionality. Further studies with a large number of gender-matched participants are needed, to confirm the results obtained in this exploratory study.

Background and Objective: Coronary bypass operations are commonly performed for the treatment of ischemic heart diseases. Coronary artery bypass surgery with autologous human saphenous vein maintains its importance as a commonly used therapy for advanced atherosclerosis. Vascular inflammation-related intimal hyperplasia and atherosclerotic progress have major roles in the pathogenesis of saphenous vein graft disease., Methods: In our study, we investigated the effect of anacardic acid (AA), which is a bioactive phytochemical in the shell of Anacardium occidentale, on atherosclerosis considering its inhibitory effect on NF-κB. We observed relative ICAM-1 and NF-κB mRNA levels by qRT-PCR method in a TNF-α- induced inflammation model of saphenous vein endothelial cell culture after 0.1, 0.5, 1 and 5 μM of AA were applied to the cells. In addition, protein levels of ICAM-1 and NF-κB were evaluated by immunofluorescent staining. The results were compared between different concentrations of AA, and also with the control group., Results: It was found that 5 μM, 1 μM and 0.5 μM of AA had toxic effects, while cytotoxicity decreased when 0.1 μM of AA was applied both alone and with TNF-α. When AA was applied with TNF-α, there was a decrease and suppression in NF-κB expression compared with the TNF-α group. TNF-α-induced ICAM-1 expression was significantly reduced more in the AA-applied group than in the TNF-α group., Conclusion: In accordance with our results, it can be said that AA has a protective role in the pathogenesis of atherosclerosis and hence in saphenous vein graft disease., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Objectives: In varicose veins, vascular smooth muscle cells (VSMCs) often shows phenotypic transition and abnormal proliferation and migration. Evidence suggests the FOXC2-Notch pathway may be involved in the pathogenesis of varicose veins. Here, this study aimed to explore the role of long non-coding RNA FOXC2-AS1 (FOXC2 antisense RNA 1) in phenotypic transition, proliferation, and migration of varicose vein-derived VSMCs and to explore whether the FOXC2-Notch pathway was involved in this process., Methods: The effect of FOXC2-AS1 on the proliferation and migration of human great saphenous vein smooth muscle cells (SV-SMCs) was analyzed using MTT assay and Transwell migration assay, respectively. The levels of contractile marker SM22α and synthetic marker osteopontin were measured by immunohistochemistry and Western blot to assess the phenotypic transition., Results: The human varicose veins showed thickened intima, media and adventitia layers, increased synthetic VSMCs, as well as upregulated FOXC2-AS1 and FOXC2 expression. In vitro assays showed that FOXC2-AS1 overexpression promoted phenotypic transition, proliferation, and migration of SV-SMCs. However, the effect of FOXC2-AS1 overexpression could be abrogated by both FOXC2 silencing and the Notch signaling inhibitor FLI-06. Furthermore, FOXC2-AS1 overexpression activated the Notch pathway by upregulating FOXC2., Conclusion: FOXC2-AS1 overexpression promotes phenotypic transition, proliferation, and migration of SV-SMCs, at least partially, by activating the FOXC2-Notch pathway.

Coronary artery bypass grafting (CABG) is one of the most efficient procedures for patients with advanced coronary artery disease. From all the blood vessels with the potential to be used in this procedure, the internal thoracic artery (ITA) and the saphenous vein (SV) are the most commonly applied as aortocoronary conduits. Nevertheless, in order to evaluate the graft patency and efficiency effectively, basic knowledge should be constantly expanding at the molecular level as well, as the understanding of predictive factors is still limited. In this study, we have employed the expressive microarray approach, validated with Real-Time Quantitative Polymerase Chain Reaction (RT-qPCR), to analyze the transcriptome of both venous and arterial grafts. Searching for potential molecular factors, we analyzed differentially expressed gene ontologies involved in bone development and morphogenesis, for the possibility of discovery of new markers for the evaluation of ITA and SV segment quality. Among three ontological groups of interest-"endochondral bone morphogenesis", "ossification", and "skeletal system development"-we found six genes common to all of them. BMP6 , SHOX2 , COL13A1 , CSGALNACT1 , RUNX2, and STC1 showed differential expression patterns in both analyzed vessels. STC1 and COL13A1 were upregulated in ITA samples, whereas others were upregulated in SV. With regard to the Runx2 protein function in osteogenic phenotype regulation, the RUNX2 gene seems to be of paramount importance in assessing the potential of ITA, SV, and other vessels used in the CABG procedure. Overall, the presented study provided valuable insight into the molecular background of conduit characterization, and thus indicated genes that may be the target of subsequent studies, also at the protein level. Moreover, it has been suggested that RUNX2 may be recognized as a molecular marker of osteogenic changes in human blood vessels.

Rationale: In response to blood vessel wall injury, aberrant proliferation of vascular smooth muscle cells (SMCs) causes pathological remodeling. However, the controlling mechanisms are not completely understood., Objective: We recently showed that the human long noncoding RNA, SMILR, promotes vascular SMCs proliferation by a hitherto unknown mechanism. Here, we assess the therapeutic potential of SMILR inhibition and detail the molecular mechanism of action., Methods and Results: We used deep RNA-sequencing of human saphenous vein SMCs stimulated with IL (interleukin)-1α and PDGF (platelet-derived growth factor)-BB with SMILR knockdown (siRNA) or overexpression (lentivirus), to identify SMILR-regulated genes. This revealed a SMILR-dependent network essential for cell cycle progression. In particular, we found using the fluorescent ubiquitination-based cell cycle indicator viral system that SMILR regulates the late mitotic phase of the cell cycle and cytokinesis with SMILR knockdown resulting in ≈10% increase in binucleated cells. SMILR pulldowns further revealed its potential molecular mechanism, which involves an interaction with the mRNA of the late mitotic protein CENPF (centromere protein F) and the regulatory Staufen1 RNA-binding protein. SMILR and this downstream axis were also found to be activated in the human ex vivo vein graft pathological model and in primary human coronary artery SMCs and atherosclerotic plaques obtained at carotid endarterectomy. Finally, to assess the therapeutic potential of SMILR, we used a novel siRNA approach in the ex vivo vein graft model (within the 30 minutes clinical time frame that would occur between harvest and implant) to assess the reduction of proliferation by EdU incorporation. SMILR knockdown led to a marked decrease in proliferation from ≈29% in controls to ≈5% with SMILR depletion., Conclusions: Collectively, we demonstrate that SMILR is a critical mediator of vascular SMC proliferation via direct regulation of mitotic progression. Our data further reveal a potential SMILR-targeting intervention to limit atherogenesis and adverse vascular remodeling.

Resuscitation with 0.9% Normal Saline (NS), a non-buffered acidic solution, leads to increased morbidity and mortality in the critically ill. The goal of this study was to determine the molecular mechanisms of endothelial injury after exposure to NS. The hypothesis of this investigation is that exposure of endothelium to NS would lead to loss of cell membrane integrity, resulting in release of ATP, activation of the purinergic receptor (P2X7R), and subsequent activation of stress activated signaling pathways and inflammation. Human saphenous vein endothelial cells (HSVEC) incubated in NS, but not buffered electrolyte solution (Plasma-Lyte, PL), exhibited abnormal morphology and increased release of lactate dehydrogenase (LDH), adenosine triphosphate (ATP), and decreased transendothelial resistance (TEER), suggesting loss of membrane integrity. Incubation of intact rat aorta (RA) or human saphenous vein in NS but not PL led to impaired endothelial-dependent relaxation which was ameliorated by apyrase (hydrolyzes ATP) or SB203580 (p38 MAPK inhibitor). Exposure of HSVEC to NS but not PL led to activation of p38 MAPK and its downstream substrate, MAPKAP kinase 2 (MK2). Treatment of HSVEC with exogenous ATP led to interleukin 1β (IL-1β) release and increased vascular cell adhesion molecule (VCAM) expression. Treatment of RA with IL-1β led to impaired endothelial relaxation. IL-1β treatment of HSVEC led to increases in p38 MAPK and MK2 phosphorylation, and increased levels of arginase II. Incubation of porcine saphenous vein (PSV) in PL with pH adjusted to 6.0 or less also led to impaired endothelial function, suggesting that the acidic nature of NS is what contributes to endothelial dysfunction. Volume overload resuscitation in a porcine model after hemorrhage with NS, but not PL, led to acidosis and impaired endothelial function. These data suggest that endothelial dysfunction caused by exposure to acidic, non-buffered NS is associated with loss of membrane integrity, release of ATP, and is modulated by P2X7R-mediated inflammatory responses., Competing Interests: The authors have declared that no competing interests exist.

Objective- To determine the role of the oncofetal protein TPBG (trophoblast glycoprotein) in normal vascular function and reparative vascularization. Approach and Results- Immunohistochemistry of human veins was used to show TPBG expression in vascular smooth muscle cells and adventitial pericyte-like cells (APCs). ELISA, Western blot, immunocytochemistry, and proximity ligation assays evidenced a hypoxia-dependent upregulation of TPBG in APCs not found in vascular smooth muscle cells or endothelial cells. This involves the transcriptional modulator CITED2 (Atypical chemokine receptor 3 CBP/p300-interacting transactivator with glutamic acid (E)/aspartic acid (D)-rich tail) and downstream activation of CXCL12 (chemokine [C-X-C motif] ligand-12) signaling through the CXCR7 (C-X-C chemokine receptor type 7) receptor and ERK1/2 (extracellular signal-regulated kinases 1/2). TPBG silencing by siRNA transfection downregulated CXCL12, CXCR7, and pERK (phospho Thr202/Tyr204 ERK1/2) and reduced the APC migratory and proangiogenic capacities. TPBG forced expression induced opposite effects, which were associated with the formation of CXCR7/CXCR4 (C-X-C chemokine receptor type 4) heterodimers and could be contrasted by CXCL12 and CXCR7 neutralization. In vivo Matrigel plug assays using APCs with or without TPBG silencing evidenced TPBG is essential for angiogenesis. Finally, in immunosuppressed mice with limb ischemia, intramuscular injection of TPBG-overexpressing APCs surpassed naïve APCs in enhancing perfusion recovery and reducing the rate of toe necrosis. Conclusions- TPBG orchestrates the migratory and angiogenic activities of pericytes through the activation of the CXCL12/CXCR7/pERK axis. This novel mechanism could be a relevant target for therapeutic improvement of reparative angiogenesis.

Background: Varicose great saphenous veins (VGSVs) are a common disorder with a high incidence, but the pathogenesis is unclear. This study was designed to measure the changes in matrix metalloproteinases (MMPs) and the tissue inhibitor of metalloproteinases (TIMPs) in different segments from VGSV walls to determine the relationship between MMPs, TIMPs expression, and expansion of the venous wall., Methods: Twenty-one VGSV and 12 normal great saphenous vein (GSV) specimens were collected. Venous walls in the two groups, expression of MMP-2, MMP-9, TIMP-1, and TIMP-2 proteins, protein-positive expression ratios, mRNA expression, and protein content were determined by immunohistochemistry, PCR, and western blot., Results: The MMP-2, MMP-9, TIMP-1, and TIMP-2 protein-positive expression ratios, mRNA expression in the upper, middle, and lower segments in the VGSV group were significantly higher than the corresponding regions in the GSV group, respectively. The MMP-2, MMP-9, TIMP-1, and TIMP-2 protein-positive expression ratios, mRNA expression, and protein concentrations in the lower segments in the VGSV group were also significantly higher than the upper and middle segments in the VGSV group and the corresponding regions in the GSV group, respectively., Conclusions: Under high hemodynamics, disequilibrium of MMPs and TIMPs from VGSVs exists within the upper, middle, and lower segments of VGSVs. These results suggested that MMPs and TIMPs participate in the process of venous wall remodeling and may be one of the mechanisms associated with the formation and development in varicose veins.

Background: Cardiopulmonary bypass (CPB) applied during coronary artery bypass grafting (CABG), promotes inflammation, generation of reactive oxygen species (ROS) and up-regulation of matrix metalloproteinases (MMPs). All these complications may lead to contractile dysfunction, restenosis and early graft failure, restricting long-term efficacy of bypass grafts. Low-dose doxycycline is a potent MMP inhibitor and ROS scavenger. In this study, we aimed to investigate the effects of doxycycline on ROS generation, MMP regulation and contractile dysfunction induced by H 2 O 2 in human saphenous vein (HSV) grafts. Methods: HSV grafts (n=7) were divided into four groups after removing endothelial layer by mechanical scratching and incubated with 10 µM H 2 O 2 and/or 10 µM doxycycline for 16 hrs. Untreated segments served as control. Concentration-response curves to noradrenaline (NA), potassium chloride (KCl), serotonin (5-HT) and papaverine were performed. Superoxide anion and other ROS levels were determined by using lucigenin- and luminol-enhanced chemiluminescence assays, respectively. Expression/activity of gelatinases (MMP-2/MMP-9) was examined by gelatin zymography. MMP-13 expression was evaluated by immunostaining/immunoscoring. Results: H 2 O 2 incubation increased superoxide anion and other ROS levels. Doxycycline prevented these increments. H 2 O 2 suppressed contractile responses to NA, KCl and 5-HT. Doxycycline ameliorated contractions to NA and KCl but not to 5-HT. H 2 O 2 or doxycycline did not altered relaxation to papaverine. MMP-2 and MMP-13 expression increased with H 2 O 2 , but doxycycline inhibited MMP-2 up-regulation/activation. Conclusion: Low-dose doxycycline may have beneficial effects on increased oxidative stress, MMP up-regulation/activation and contractile dysfunction in HSV grafts., Competing Interests: The authors report no conflicts of interest in this work.

Objective: The study aimed to investigate the biologic effects of the 1470-nm endovenous laser (EVL), with a jacketed fiber and a radial fiber, during EVL ablation of an ex vivo dominant extrafascial tributary of the great saphenous vein in our in vitro model by histology and immunohistochemistry., Methods: Ten segments of the dominant extrafascial tributary of the great saphenous vein were harvested by a consultant vascular surgeon from patients during routine varicose vein surgery. Six segments were treated using an ex vivo model of our design by a 1470-nm EVL with a jacketed fiber. The other four segments were also treated by a 1470-nm EVL but with a radial-firing fiber. Each segment was split into five sections and treated at five different linear endovenous energy densities (LEEDs) at 10 W: 0, 20, 40, 60, and 80 J/cm. The veins were incubated and subsections collected at 6 and 24 hours after treatment. Subsections were immersed in buffered formalin and taken for histologic and immunohistochemical analysis. Histopathologic analysis was then performed., Results: Treatment with the radial fiber led to a pattern of damage that was more homogeneous than with the jacketed fiber, with no carbonization of tissue present. Significant transmural damage and necrosis were observed at LEEDs of 60 and 80 J/cm in both treatment groups. At the same LEEDs, p53 and caspase 3 analysis showed that transmural cell wall vein death (necrosis or apoptosis) occurred by 6 hours after treatment with both fibers., Conclusions: There was a significant difference in the effects of treatment with a jacketed fiber and a radial fiber in EVL ablation in vitro. Although both fibers caused transmural vein wall cell death at similar LEEDs, the pattern of damage with the radial fiber was more homogeneous. There was no overtreatment of tissue in terms of carbonization after treatment with the radial fiber. Treatment with the jacketed fiber showed carbonization of tissue at the same LEEDs., (Copyright © 2019. Published by Elsevier Inc.)