| 193391. |
- Samano, Ninos, 1972-, et al.
(författare)
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Saphenous veins in coronary artery bypass grafting need external support
- 2021
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Ingår i: Asian cardiovascular & thoracic annals. - : Sage Publications. - 1816-5370 .- 0218-4923. ; 29:5, s. 457-467
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Forskningsöversikt (refereegranskat)abstract
- The saphenous vein is the most commonly used conduit for coronary artery bypass grafting. Arterial grafts are harvested with the outer pedicle intact whereas saphenous veins are harvested with the pedicle removed in the conventional graft harvesting technique. This conventional procedure causes considerable vascular damage. One strategy to improve vein graft patency has been to provide external support. Ongoing studies show that fitting a metal external support improves conventionally harvested saphenous vein graft patency. On the other hand, the no-touch technique of harvesting the saphenous vein provides an improved graft with long-term patency comparable to that of the internal mammary artery. This improvement is suggested to be due to preservation of vessel structures. Interestingly, many of the mechanisms proposed to be associated with the beneficial actions of an artificial external support on saphenous vein graft patency are similar to those underlying the beneficial effect of no-touch saphenous vein grafts where the intact outer layer acts as a natural support. Additional actions of external supports have been advocated, including promotion of angiogenesis, increased production of vascular-protective factors, and protection of endothelial cells. Using no-touch harvesting, normal vascular architecture is maintained, tissue and cell damage is minimized, and factors beneficial for graft patency are preserved. In this review, the significance of external support of saphenous vein grafts in coronary artery bypass grafting is discussed.
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| 193392. |
- Samano, Ninos, 1972-, et al.
(författare)
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Surgical Aspects of No-Touch Saphenous Vein Graft Harvesting in CABG : Clinical and Angiographic Follow-Up at 3 Months
- 2019
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Ingår i: Brazilian Journal of Cardiovascular Surgery. - : Sociedade Brasileira de Cirurgia Cardiovascular. - 0102-7638 .- 1678-9741. ; 34:1, s. 98-100
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Tidskriftsartikel (refereegranskat)abstract
- With more than 800,000 coronary artery bypass grafting (CABG) operations annually worldwide and the saphenous vein being the most common conduit used, there is no question that improving saphenous vein graft patency is one of the most important tasks in CABG. This video describes the no-touch harvesting procedure of the saphenous vein on an 80-year old man with hypertension, hyperlipidemia and a previous myocardial infarction with percutaneous coronary intervention to the right coronary artery. He was complaining of exertional chest pain and was diagnosed with stable angina pectoris. The coronary angiography showed advanced three vessel disease with significant stenoses in the left anterior descending (LAD) artery, two marginal arteries (MAs) and the posterior descending artery (PDA), in addition to an occluded diagonal artery (DA). The patient received a triple sequential no-touch vein graft to the PDA and two MAs together with a double sequential no-touch vein graft to the DA and LAD. A vein graft was used to bypass the LAD due to the age of the patient and the low degree of stenosis in the LAD. The no-touch harvesting technique is described in detail in the film with complete narration. A follow-up of this patient was performed at three months both clinically and with a computed tomography angiography (CTA). No angina pectoris symptoms were reported by the patient and the wounds in the chest and lower limb were completely healed. The CTA showed patent no-touch saphenous vein grafts to all the distal anastomoses.
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| 193393. |
- Samano, Ninos, 1972-, et al.
(författare)
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The no-touch saphenous vein for coronary artery bypass grafting maintains a patency, after 16 years, comparable to the left internal thoracic artery : a randomized trial
- 2015
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Ingår i: Journal of Thoracic and Cardiovascular Surgery. - : Mosby-Elsevier. - 0022-5223 .- 1097-685X. ; 150:4, s. 880-888
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: This study investigates whether the no-touch (NT) vein graft, at a mean time of 16 years, maintains a significantly higher patency rate than conventional (C) vein grafts and still has patency comparable to that of the left internal thoracic artery (LITA).Methods: A total of 156 patients accepted for coronary artery bypass grafting were randomly allocated to 1 of 3 groups. In the C group, the saphenous vein (SV) was stripped and distended. In the intermediate group, the SV was stripped but not distended. In the NT group, the SV was neither stripped nor distended, but rather harvested with a fat pedicle. This study is an angiographic follow-up of the C and NT groups, at a mean time of 16 years postoperatively.Results: Fifty-four patients were included (C group = 27; NT group = 27). In all, 72 and 75 vein grafts were completed in groups C and NT, respectively. Crude SV graft patency was 64% in the C group versus 83% in the NT group (P = .03), which was similar to the patency of the LITA (88%). The harvesting technique had a major impact on the patency with a hazard ratio for occlusion of 1.83 for the C group (P = .04).Conclusions: Harvesting the SV with the NT technique conferred, at a mean time of 16 years, a significantly higher patency than the conventional technique that was still comparable to that of the LITA.
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| 193394. |
- Samano, Ninos, 1972-, et al.
(författare)
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The no-touch saphenous vein graft in elderly coronary bypass patients with multiple comorbidities is a promising conduit to substitute the left internal thoracic artery
- 2017
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Ingår i: Journal of Thoracic and Cardiovascular Surgery. - : Mosby Inc.. - 0022-5223 .- 1097-685X. ; 154:2, s. 457-466.e3
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: We investigated the patency rates of no-touch saphenous vein grafts anastomosed to the left anterior descending artery compared with the left internal thoracic artery. Further, we compared the patency of no-touch vein grafts to the left anterior descending artery with the patency of no-touch vein grafts to other coronary arteries.METHODS: Of 2635 consecutive patients undergoing coronary artery bypass grafting between 2003 and 2008, 168 (6.3%) were given at least a saphenous vein graft to the left anterior descending artery to avoid harvesting complications in high-risk patients or in response to a left internal thoracic artery injury. A total of 97 patients were consecutively included after informed consent. A clinical examination and computed tomography angiography were performed on 91 patients at a mean of 6 (4-9) years.RESULTS: The mean age of patients was 75.6 ± 8.5 years. Postoperatively, 88.7% of patients (86/97) were free of angina. The 91 examined patients had 163 grafts with 286 distal anastomoses. Crude patency, according to distal anastomoses, was 94.4% (270/286). The patency of single versus sequential no-touch vein grafts to the left anterior descending artery was 98% (50/51) versus 92.5% (37/40). The total patency rate was 95.6% (87/91), similar to the reported patency rate for the left internal thoracic artery. The no-touch grafts to the left anterior descending artery versus other coronaries had a patency of 95.6% (87/91) versus 93.8% (183/195), a high similarity confirmed by an equivalence analysis.CONCLUSIONS: In elderly coronary bypass patients with multiple comorbidities, a no-touch saphenous vein graft is a promising substitute for the left internal thoracic artery.
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| 193395. |
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| 193396. |
- Samano, Ninos, 1972-, et al.
(författare)
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Twenty-Five Years of No-Touch Saphenous Vein Harvesting for Coronary Artery Bypass Grafting : Structural Observations and Impact on Graft Performance
- 2020
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Ingår i: Brazilian Journal of Cardiovascular Surgery. - : Sociedade Brasileira de Cirurgia Cardiovascular. - 0102-7638 .- 1678-9741. ; 35:1, s. 91-99
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Forskningsöversikt (refereegranskat)abstract
- The saphenous vein is the most common conduit used in coronary artery bypass grafting (CABG) yet its failure rate is higher compared to arterial grafts. An improvement in saphenous vein graft performance is therefore a major priority in CABG. No-touch harvesting of the saphenous vein is one of the few interventions that has shown improved patency rates, comparable to that of the left internal thoracic artery. After more than two decades of no-touch research, this technique is now recognized as a Class IIa recommendation in the 2018 European Society of Cardiology and the European Association for Cardio-Thoracic Surgery guidelines on myocardial revascularization. In this review, we describe the structural alterations that occur in conventional versus no-touch saphenous vein grafts and how these changes affect graft patency. In addition, we discuss various strategies aimed at repairing saphenous vein grafts prepared at conventional CABG.
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| 193397. |
- Samano, Ninos, 1972-, et al.
(författare)
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What is the impact of preserving the endothelium on saphenous vein graft performance? Comments on the 'NO' touch harvesting technique
- 2021
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Ingår i: Journal of Cardiothoracic Surgery. - : BioMed Central (BMC). - 1749-8090. ; 16:1
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Tidskriftsartikel (refereegranskat)abstract
- Saphenous veins used for coronary artery bypass surgery are subjected to considerable vascular trauma when harvested by conventional methods. This vascular damage is responsible, at least in part, for the inferior patency of the saphenous vein when compared with the internal thoracic artery. The performance of saphenous vein grafts is improved when this conduit is harvested atraumatically using the no-touch technique. There is growing evidence that the success of the no-touch technique is due to the preservation of a number of vascular structures including the endothelium, vasa vasorum and perivascular fat. There is conflicting evidence regarding the degree of endothelial damage to the endothelium of conventional versus no-touch saphenous vein grafts. In general, it has been shown that this single layer of cells lining the lumen exhibits considerable damage associated with a combination of vascular trauma and high pressure intraluminal distension. Increased platelet aggregation and thrombus formation at the exposed subendothelial membrane is due to a local reduction of endothelium-derived factors including nitric oxide. In addition, damage to the vasa vasorum of conventionally-harvested veins will reduce transmural blood flow, a condition shown to promote neointimal hyperplasia and atheroma formation. By stripping off the perivascular fat during conventional harvesting, mechanical support of the graft is reduced and the source of adipocyte-derived factors potentially beneficial for graft patency removed. While most agree that endothelial damage to the saphenous vein affects graft patency, the contribution of other tissue-derived factors affected by vascular damage at harvesting need to be considered.
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| 193398. |
- Samanta, Sumanta, et al.
(författare)
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Heparin-Derived Theranostic Nanoprobes Overcome the Blood-Brain Barrier and Target Glioma in Murine Model
- 2022
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Ingår i: Advanced Therapeutics. - : John Wiley & Sons. - 2366-3987. ; 5:6
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Tidskriftsartikel (refereegranskat)abstract
- The poor permeability of theranostic agents across the blood-brain barrier (BBB) significantly hampers the development of new treatment modalities for neurological diseases. A new biomimetic nanocarrier is discovered using heparin (HP) that effectively passes the BBB and targets glioblastoma. Specifically, HP-coated gold nanoparticles (HP-AuNPs) are designed that are labeled with three different imaging modalities namely, fluorescein (FITC-HP-AuNP), radioisotope (68)Gallium (Ga-68-HP-AuNPs), and MRI active gadolinium (Gd-HP-AuNPs). The systemic infusion of FITC-HP-AuNPs in three different mouse strains (C57BL/6JRj, FVB, and NMRI-nude) displays excellent penetration and reveals uniform distribution of fluorescent particles in the brain parenchyma (69-86%) with some accumulation in neurons (8-18%) and microglia (4-10%). Tail-vein administration of radiolabeled Ga-68-HP-AuNPs in healthy rats also show Ga-68-HP-AuNP inside the brain parenchyma and in areas containing cerebrospinal fluid, such as the lateral ventricles, the cerebellum, and brain stem. Finally, tail-vein administration of Gd-HP-AuNPs (that displays approximate to threefold higher relaxivity than that of commercial Gd-DTPA) in an orthotopic glioblastoma (U87MG xenograft) model in nude mice demonstrates enrichment of T1-contrast at the intracranial tumor with a gradual increase in the contrast in the tumor region between 1 and 3 h. It is believed, the finding offers the untapped potential of HP-derived-NPs to deliver cargo molecules for treating neurological disorders.
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| 193399. |
- Samanta, Sumanta, et al.
(författare)
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Interpenetrating gallol functionalized tissue adhesive hyaluronic acid hydrogel polarizes macrophages to an immunosuppressive phenotype
- 2022
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Ingår i: Acta Biomaterialia. - : Elsevier. - 1742-7061 .- 1878-7568. ; 142, s. 36-48
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Tidskriftsartikel (refereegranskat)abstract
- Innovative scaffold designs that modulate the local inflammatory microenvironment through favorable macrophage polarization and suppressing oxidative stress are needed for successful clinical translation of regenerative cell therapies and graft integration. We herein report derivation of a hydrazone-crosslinked gallol functionalized hyaluronic acid (HA-GA)-based hydrogel that displayed outstanding viscoelastic properties and immunomodulatory characteristics. Grafting of 6% gallol (GA) to a HA-backbone formed an interpenetrative network by promoting an additional crosslink between the gallol groups in addition to hydrazone crosslinking. This significantly enhanced the mechanical stability and displayed shear-thinning/self-healing characteristics, facilitated tissue adhesive properties to porcine tissue and also displayed radical scavenging properties, protecting encapsulated fibroblasts from peroxide challenge. The THP-1 human macrophage cell line or primary bone-marrow-derived murine macrophages cultured within HA-GA gels displayed selective polarization to a predominantly anti-inflammatory phenotype by upregulating IL4ra, IL-10, TGF-β, and TGF-βR1 expression when compared with HA-HA gels. Conversely, culturing of pro-inflammatory activated primary murine macrophages in HA-GA gels resulted in a significant reduction of pro-inflammatory TNF-α, IL-1β, SOCS3 and IL-6 marker expression, and upregulated expression of anti-inflammatory cytokines including TGF-β. Finally, when the gels were implanted subcutaneously into healthy mice, we observed infiltration of pro-inflammatory myeloid cells in HA-HA gels, while immunosuppressive phenotypes were observed within the HA-GA gels. Taken together these data suggest that HA-GA gels are an ideal injectable scaffold for viable immunotherapeutic interventions.Statement of significanceHost immune response against the implanted scaffolds that are designed to deliver stem cells or therapeutic proteins in vivo significantly limits the functional outcome. For this reason, we have designed immunomodulatory injectable scaffolds that can favorably polarize the recruited macrophages and impart antioxidant properties to suppress oxidative stress. Specifically, we have tailored a hyaluronic acid-based extracellular matrix mimetic injectable scaffold that is grafted with immunomodulatory gallol moiety. Gallol functionalization of hydrogel not only enhanced the mechanical properties of the scaffold by forming an interpenetrating network but also induced antioxidant properties, tissue adhesive properties, and polarized primary murine macrophages to immunosuppressive phenotype. We believe such immunoresponsive implants will pave the way for developing the next-generation of biomaterials for regenerative medicine applications.
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| 193400. |
- Samanta, S., et al.
(författare)
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Naphthalene Monoimide Derivative Ameliorates Amyloid Burden and Cognitive Decline in a Transgenic Mouse Model of Alzheimer's Disease
- 2021
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Ingår i: Advanced Therapeutics. - : Blackwell Publishing Ltd. - 2366-3987. ; 4:4
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Tidskriftsartikel (refereegranskat)abstract
- Alzheimer's disease (AD) is a major neurodegenerative disorder and the leading cause of dementia worldwide. Predominantly, misfolding and aggregation of amyloid-β (Aβ) peptides associated with multifaceted toxicity is the neuropathological hallmark of AD pathogenesis and, thus the primary therapeutic target to ameliorate neuronal toxicity and cognitive deficits. Herein, the design, synthesis, and evaluation of small molecule inhibitors with naphthalene monoimide scaffold to ameliorate in vitro and in vivo amyloid induced neurotoxicity are reported. The detailed studies establish TGR63 as the lead candidate to rescue neuronal cells from amyloid toxicity. The in silico studies show the disruption of salt bridges and intermolecular hydrogen bonding interactions within Aβ42 fibrils by the interaction of TGR63, causing destabilization of Aβ42 assembly. Remarkably, TGR63 treatment shows a significant reduction in cortical and hippocampal amyloid burden in the progressive stages of APP/PS1 AD mice brain. Various behavioral tests demonstrate rescued cognitive deficits. The excellent biocompatibility, blood–brain barrier permeability, and therapeutic efficacy to reduce the amyloid burden make TGR63 a promising candidate for the treatment of AD.
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