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Montelione N, Catanese V, Nenna A, Gabellini T, Ferrisi C, Paolini J, Ciolli A, Barillà D, Loreni F, Chello M, Spinelli F, Stilo F. External Scaffold for Venous Graft to Treat Chronic Limb-Threatening Ischemia: Results of the FRAME Vascular Support. J Clin Med 2024; 13:2095. [PMID: 38610860 PMCID: PMC11012784 DOI: 10.3390/jcm13072095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 03/22/2024] [Accepted: 03/30/2024] [Indexed: 04/14/2024] Open
Abstract
Background: The surgical treatment of chronic limb-threatening ischemia and optimal conduit choice are extensively debated. The presence of suboptimal autologous material, such as varicosities or venous aneurysms, might impair long-term outcomes. Therefore, kink-resistant external supports have been advocated in the recent literature to improve the conduit quality and outcomes. This study analyzes the FRAME external support in venous ectasic grafts in patients with chronic limb-threatening ischemia. Methods: From September 2017 to September 2023, a total of sixteen patients underwent CLTI surgery with FRAME external support for venous grafts. The inclusion criteria for FRAME applications were varicose or ectasic autologous material with a diameter ≥ 4.5 and ≤ 8 mm in an isolated segment or in the entire vein and a higher risk of bypass extrinsic compression (e.g., extra-anatomical venous bypass course). Results: Technical success and intraoperative patency were achieved in all cases. At 30 days, the limb salvage and survival rates were 100%. The primary bypass patency was 93.7% due to an early graft occlusion. No graft infection was registered. In one case, dehiscence of the surgical wound was treated by surgical debridement and antibiotic therapy. Minor amputation was required in four patients. Over a median follow-up of 32 months, two occlusions were observed; one was treated with reoperation and the other with major amputation. The primary patency was 68.7% and the assisted primary patency was 75%. Limb salvage rates observed during the entire follow-up period were 87.5%. No graft infections or dilatation of the reinforced veins were registered. Conclusions: For patients with CLTI undergoing infrainguinal bypass, satisfactory results in terms of patency and limb salvage rates were achieved using the autologous venous material, even if ectasic or varicose, with the vascular external support FRAME.
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Affiliation(s)
- Nunzio Montelione
- Vascular Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy; (N.M.); (V.C.); (T.G.); (J.P.); (A.C.); (F.S.); (F.S.)
| | - Vincenzo Catanese
- Vascular Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy; (N.M.); (V.C.); (T.G.); (J.P.); (A.C.); (F.S.); (F.S.)
| | - Antonio Nenna
- Cardiac Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy; (C.F.); (F.L.)
| | - Teresa Gabellini
- Vascular Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy; (N.M.); (V.C.); (T.G.); (J.P.); (A.C.); (F.S.); (F.S.)
- Vascular Surgery Residency Program, University of Ferrara, 44124 Ferrara, Italy
| | - Chiara Ferrisi
- Cardiac Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy; (C.F.); (F.L.)
- Cardiac Surgery Residency Program, Università Campus Bio-Medico di Roma, 00128 Rome, Italy
| | - Julia Paolini
- Vascular Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy; (N.M.); (V.C.); (T.G.); (J.P.); (A.C.); (F.S.); (F.S.)
- Vascular Surgery Residency Program, Università Cattolica del Sacro Cuore, 00128 Rome, Italy
| | - Alessandro Ciolli
- Vascular Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy; (N.M.); (V.C.); (T.G.); (J.P.); (A.C.); (F.S.); (F.S.)
- Vascular Surgery Residency Program, Università Cattolica del Sacro Cuore, 00128 Rome, Italy
| | - David Barillà
- Vascular Surgery, Humanitas Clinical and Research Center—IRCCS, Rozzano, 20148 Milan, Italy
| | - Francesco Loreni
- Cardiac Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy; (C.F.); (F.L.)
- Cardiac Surgery Residency Program, Università Campus Bio-Medico di Roma, 00128 Rome, Italy
| | - Massimo Chello
- Cardiac Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy; (C.F.); (F.L.)
| | - Francesco Spinelli
- Vascular Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy; (N.M.); (V.C.); (T.G.); (J.P.); (A.C.); (F.S.); (F.S.)
| | - Francesco Stilo
- Vascular Surgery, Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy; (N.M.); (V.C.); (T.G.); (J.P.); (A.C.); (F.S.); (F.S.)
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2
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Russu E, Arbanasi EM, Chirila TV, Muresan AV. Therapeutic strategies based on non-ionizing radiation to prevent venous neointimal hyperplasia: the relevance for stenosed arteriovenous fistula, and the role of vascular compliance. Front Cardiovasc Med 2024; 11:1356671. [PMID: 38374996 PMCID: PMC10875031 DOI: 10.3389/fcvm.2024.1356671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 01/23/2024] [Indexed: 02/21/2024] Open
Abstract
We have reviewed the development and current status of therapies based on exposure to non-ionizing radiation (with a photon energy less than 10 eV) aimed at suppressing the venous neointimal hyperplasia, and consequentially at avoiding stenosis in arteriovenous grafts. Due to the drawbacks associated with the medical use of ionizing radiation, prominently the radiation-induced cardiovascular disease, the availability of procedures using non-ionizing radiation is becoming a noteworthy objective for the current research. Further, the focus of the review was the use of such procedures for improving the vascular access function and assuring the clinical success of arteriovenous fistulae in hemodialysis patients. Following a brief discussion of the physical principles underlying radiotherapy, the current methods based on non-ionizing radiation, either in use or under development, were described in detail. There are currently five such techniques, including photodynamic therapy (PDT), far-infrared therapy, photochemical tissue passivation (PTP), Alucent vascular scaffolding, and adventitial photocrosslinking. The last three are contingent on the mechanical stiffening achievable by the exogenous photochemical crosslinking of tissular collagen, a process that leads to the decrease of venous compliance. As there are conflicting opinions on the role of compliance mismatch between arterial and venous conduits in a graft, this aspect was also considered in our review.
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Affiliation(s)
- Eliza Russu
- Clinic of Vascular Surgery, Mures County Emergency Hospital, Targu Mures, Romania
- Department of Vascular Surgery, George Emil Palade University of Medicine, Pharmacy, Sciences and Technology of Targu Mures, Targu Mures, Romania
| | - Emil-Marian Arbanasi
- Clinic of Vascular Surgery, Mures County Emergency Hospital, Targu Mures, Romania
- Department of Vascular Surgery, George Emil Palade University of Medicine, Pharmacy, Sciences and Technology of Targu Mures, Targu Mures, Romania
- Doctoral School of Medicine and Pharmacy, George Emil Palade University of Medicine, Pharmacy, Sciences and Technology of Targu Mures, Targu Mures, Romania
- Centre for Advanced Medical and Pharmaceutical Research (CCAMF), George Emil Palade University of Medicine, Pharmacy, Sciences and Technology of Targu Mures, Targu Mures, Romania
| | - Traian V. Chirila
- Centre for Advanced Medical and Pharmaceutical Research (CCAMF), George Emil Palade University of Medicine, Pharmacy, Sciences and Technology of Targu Mures, Targu Mures, Romania
- Queensland Eye Institute, Woolloongabba, QLD, Australia
- Faculty of Medicine, George Emil Palade University of Medicine, Pharmacy, Sciences and Technology of Targu Mures, Targu Mures, Romania
- School of Chemistry and Physics, Queensland University of Technology, Brisbane, QLD, Australia
- Australian Institute of Bioengineering and Nanotechnology (AIBN), University of Queensland, St Lucia, QLD, Australia
| | - Adrian V. Muresan
- Clinic of Vascular Surgery, Mures County Emergency Hospital, Targu Mures, Romania
- Department of Vascular Surgery, George Emil Palade University of Medicine, Pharmacy, Sciences and Technology of Targu Mures, Targu Mures, Romania
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3
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Dai L, Yu W, Yu Y. New strategy of using double-network hydrogel extravascular stent for preventing venous graft restenosis after coronary artery bypass grafting. Perfusion 2023; 38:1240-1249. [PMID: 35511059 DOI: 10.1177/02676591221099813] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE Effective therapies for the prevention of vein graft failure, which frequently occurs in coronary artery bypass grafting (CABG) due to intimal hyperplasia (IH), are still lacking. Here, we investigated the effects of the perivenous application of double-network hydrogel on vein grafts in carotid artery bypass grafting in a rabbit model. METHODS Healthy New Zealand white rabbits were randomized into the following groups: no graft, graft, or graft + Double-network hydrogel external stent (DNHES). The rabbits' carotid artery was bypassed via the jugular vein. Double-network hydrogel external stent was wrapped around the jugular graft after the anastomoses were completed. Blood flow parameters and tissue histology of the vein grafts were evaluated. RESULTS Compared with the untreated vein grafts at 12 weeks after the surgery, the DNHES significantly improved graft flow, attenuated intimal and medial thickening, reduced the anti-proliferating cell nuclear antigen proliferation index of the vein grafts, decreased the mRNA and protein expression of Mitogen-Activated Protein Kinase (MAPK) and Transforming Growth Factor-β (TGF-β), and increased the mRNA and protein expression of endothelial Nitric Oxide Synthase (eNOS). CONCLUSION The perivenous application of DNHES exerts beneficial effects on vein grafts, reduces the inflammatory response in carotid artery bypass grafting in a rabbit model, and appears to be a safe and promising strategy to prevent vein graft failure.
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Affiliation(s)
- Longsheng Dai
- Department of Cardiac Surgery, Beijing An Zhen Hospital, Capital Medical University, Beijing, China
| | - Wenyuan Yu
- Department of Cardiac Surgery, Beijing An Zhen Hospital, Capital Medical University, Beijing, China
| | - Yang Yu
- Department of Cardiac Surgery, Beijing An Zhen Hospital, Capital Medical University, Beijing, China
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4
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Ramachandra AB, Latorre M, Szafron JM, Marsden AL, Humphrey JD. Vascular adaptation in the presence of external support - A modeling study. J Mech Behav Biomed Mater 2020; 110:103943. [PMID: 32957235 DOI: 10.1016/j.jmbbm.2020.103943] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 04/24/2020] [Accepted: 06/17/2020] [Indexed: 10/24/2022]
Abstract
Vascular grafts have long been used to replace damaged or diseased vessels with considerable success, but a new approach is emerging where native vessels are merely supported, not replaced. Although external supports have been evaluated in diverse situations - ranging from aneurysmal disease to vein grafts or the Ross operation - optimal supports and procedures remain wanting. In this paper, we present a novel application of a growth and remodeling model well suited for parametrically exploring multiple designs of external supports while accounting for mechanobiological and immunobiological responses of the supported native vessel. These results suggest that a load bearing external support can reduce vessel thickening in response to pressure elevation. Results also suggest that the final adaptive state of the vessel depends on the structural stiffness of the support via a mechano-driven adaptation, although luminal encroachment may be a complication in the presence of chronic inflammation. Finally, the supported vessel can stiffen (structurally and materially) along circumferential and axial directions, which could have implications on overall hemodynamics and thus subsequent vascular remodeling. The proposed framework can provide valuable insights into vascular adaptation in the presence of external support, accelerate rational design, and aid translation of this emerging approach.
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Affiliation(s)
| | - Marcos Latorre
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Jason M Szafron
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Alison L Marsden
- Departments of Bioengineering and Pediatrics, Institute of Computational and Mathematical Engineering, Stanford University, Stanford, CA, USA
| | - Jay D Humphrey
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA; Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT, USA.
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5
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Ramachandra AB, Humphrey JD, Marsden AL. Gradual loading ameliorates maladaptation in computational simulations of vein graft growth and remodelling. J R Soc Interface 2018; 14:rsif.2016.0995. [PMID: 28566510 DOI: 10.1098/rsif.2016.0995] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 04/28/2017] [Indexed: 12/21/2022] Open
Abstract
Vein graft failure is a prevalent problem in vascular surgeries, including bypass grafting and arteriovenous fistula procedures in which veins are subjected to severe changes in pressure and flow. Animal and clinical studies provide significant insight, but understanding the complex underlying coupled mechanisms can be advanced using computational models. Towards this end, we propose a new model of venous growth and remodelling (G&R) based on a constrained mixture theory. First, we identify constitutive relations and parameters that enable venous adaptations to moderate perturbations in haemodynamics. We then fix these relations and parameters, and subject the vein to a range of combined loads (pressure and flow), from moderate to severe, and identify plausible mechanisms of adaptation versus maladaptation. We also explore the beneficial effects of gradual increases in load on adaptation. A gradual change in flow over 3 days plus an initial step change in pressure results in fewer maladaptations compared with step changes in both flow and pressure, or even a gradual change in pressure and flow over 3 days. A gradual change in flow and pressure over 8 days also enabled a successful venous adaptation for loads as severe as the arterial loads. Optimization is used to accelerate parameter estimation and the proposed framework is general enough to provide a good starting point for parameter estimations in G&R simulations.
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Affiliation(s)
- Abhay B Ramachandra
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA, USA.,Department of Pediatrics, Institute for Computational and Mathematical Engineering, Stanford, CA, USA
| | - Jay D Humphrey
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Alison L Marsden
- Department of Pediatrics, Institute for Computational and Mathematical Engineering, Stanford, CA, USA .,Department of Bioengineering, Stanford University, Stanford, CA, USA
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6
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Mawhinney JA, Mounsey CA, Taggart DP. The potential role of external venous supports in coronary artery bypass graft surgery†. Eur J Cardiothorac Surg 2017; 53:1127-1134. [DOI: 10.1093/ejcts/ezx432] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Accepted: 11/07/2017] [Indexed: 11/12/2022] Open
Affiliation(s)
| | | | - David P Taggart
- Department of Cardiothoracic Surgery, Oxford University Hospitals NHS Trust, Oxford, UK
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7
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Mylonaki I, Allémann É, Saucy F, Haefliger JA, Delie F, Jordan O. Perivascular medical devices and drug delivery systems: Making the right choices. Biomaterials 2017; 128:56-68. [PMID: 28288349 DOI: 10.1016/j.biomaterials.2017.02.028] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 02/13/2017] [Accepted: 02/26/2017] [Indexed: 12/31/2022]
Abstract
Perivascular medical devices and perivascular drug delivery systems are conceived for local application around a blood vessel during open vascular surgery. These systems provide mechanical support and/or pharmacological activity for the prevention of intimal hyperplasia following vessel injury. Despite abundant reports in the literature and numerous clinical trials, no efficient perivascular treatment is available. In this review, the existing perivascular medical devices and perivascular drug delivery systems, such as polymeric gels, meshes, sheaths, wraps, matrices, and metal meshes, are jointly evaluated. The key criteria for the design of an ideal perivascular system are identified. Perivascular treatments should have mechanical specifications that ensure system localization, prolonged retention and adequate vascular constriction. From the data gathered, it appears that a drug is necessary to increase the efficacy of these systems. As such, the release kinetics of pharmacological agents should match the development of the pathology. A successful perivascular system must combine these optimized pharmacological and mechanical properties to be efficient.
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Affiliation(s)
- Ioanna Mylonaki
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, rue Michel Servet 1, CH-1211 Geneva 4, Switzerland
| | - Éric Allémann
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, rue Michel Servet 1, CH-1211 Geneva 4, Switzerland
| | - François Saucy
- Department of Vascular Surgery, Lausanne University Hospital, rue du Bugnon 46, CH-1011 Lausanne, Switzerland
| | - Jacques-Antoine Haefliger
- Department of Vascular Surgery, Lausanne University Hospital, rue du Bugnon 46, CH-1011 Lausanne, Switzerland
| | - Florence Delie
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, rue Michel Servet 1, CH-1211 Geneva 4, Switzerland
| | - Olivier Jordan
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, rue Michel Servet 1, CH-1211 Geneva 4, Switzerland.
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8
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Boire TC, Balikov DA, Lee Y, Guth CM, Cheung-Flynn J, Sung HJ. Biomaterial-Based Approaches to Address Vein Graft and Hemodialysis Access Failures. Macromol Rapid Commun 2016; 37:1860-1880. [PMID: 27673474 PMCID: PMC5156561 DOI: 10.1002/marc.201600412] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 08/15/2016] [Indexed: 12/19/2022]
Abstract
Veins used as grafts in heart bypass or as access points in hemodialysis exhibit high failure rates, thereby causing significant morbidity and mortality for patients. Interventional or revisional surgeries required to correct these failures have been met with limited success and exorbitant costs, particularly for the US Centers for Medicare & Medicaid Services. Vein stenosis or occlusion leading to failure is primarily the result of neointimal hyperplasia. Systemic therapies have achieved little long-term success, indicating the need for more localized, sustained, biomaterial-based solutions. Numerous studies have demonstrated the ability of external stents to reduce neointimal hyperplasia. However, successful results from animal models have failed to translate to the clinic thus far, and no external stent is currently approved for use in the US to prevent vein graft or hemodialysis access failures. This review discusses current progress in the field, design considerations, and future perspectives for biomaterial-based external stents. More comparative studies iteratively modulating biomaterial and biomaterial-drug approaches are critical in addressing mechanistic knowledge gaps associated with external stent application to the arteriovenous environment. Addressing these gaps will ultimately lead to more viable solutions that prevent vein graft and hemodialysis access failures.
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Affiliation(s)
- Timothy C Boire
- Department of Biomedical Engineering, Vanderbilt University, 37235, Nashville, TN, USA
| | - Daniel A Balikov
- Department of Biomedical Engineering, Vanderbilt University, 37235, Nashville, TN, USA
| | - Yunki Lee
- Department of Biomedical Engineering, Vanderbilt University, 37235, Nashville, TN, USA
| | - Christy M Guth
- Division of Vascular Surgery, Department of Surgery, Vanderbilt University Medical Center, Nashville, TN, 37235, USA
| | - Joyce Cheung-Flynn
- Division of Vascular Surgery, Department of Surgery, Vanderbilt University Medical Center, Nashville, TN, 37235, USA
| | - Hak-Joon Sung
- Department of Biomedical Engineering, Vanderbilt University, 37235, Nashville, TN, USA
- Severance Biomedical Science Institute, College of Medicine, Yonsei University, Seoul, 120-752, Republic of Korea
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Mazuchova J, Pec M, Halasova E, Valentova V, Sarlinova M, Mazuch J, Zelnik S. News in Pathogenesis of Chronic Venous Insufficiency. ACTA MEDICA MARTINIANA 2016. [DOI: 10.1515/acm-2016-0006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
This review article is concentrating on the news in the pathophysiology of chronic venous insufficiency (CVD). Despite ongoing progress in understanding the molecular aspects of CVD the exact mechanism of its development remains unclear. Many different factors may play role in the pathogenesis of CVD, including changes in hydrostatic pressure, valvular incompetence, increased capillary permeability, endothelial dysfunction, activation of leukocytes, deep venous obstruction, capillary microthrombosis, ineffective function of calf muscle pump, biochemical and structural changes in the vessel wall, extracellular matrix alteration, and several other mechanisms. A better understanding of the pathophysiology is an important step in the finding of new potential treatment.
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Affiliation(s)
- J Mazuchova
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin and University Hospital in Martin, Department of Medical Biology
| | - M Pec
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin and University Hospital in Martin, Department of Medical Biology
| | - E Halasova
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin and University Hospital in Martin, Department of Medical Biology
| | - V Valentova
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin and University Hospital in Martin, Department of Medical Biology
| | - M Sarlinova
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin and University Hospital in Martin, Department of Medical Biology
| | - J Mazuch
- Clinic of Surgery and Transplant Center
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A comprehensive review on learning curve associated problems in endoscopic vein harvesting and the requirement for a standardised training programme. J Cardiothorac Surg 2016; 11:45. [PMID: 27059309 PMCID: PMC4825086 DOI: 10.1186/s13019-016-0442-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 04/04/2016] [Indexed: 11/10/2022] Open
Abstract
Endoscopic vein harvesting is becoming one of the most favourable vein harvesting techniques in multiple bypass coronary surgery, due to its short term post-operative benefits with high patient satisfaction. However, long-term graft patency has been both supported and questioned in the literature. Graft failure can be affected by harvesting methods and operator's experience. Endoscopic vein harvesting is associated with a learning curve period, during which the incidence of vein trauma is high due to unfamiliarity with the surgical technique. There is a paucity of structured learning tools for novice practitioners, meaning that training differs significantly between hospital centres. Inconsistent training methods can lead to poor surgical technique, which can have a significant impact on vein quality and stress level of the practitioner. In turn, this can lead to increased postoperative complications and longer surgical duration. The main aim of this literature review is to understand the impact of the learning curve on the vein conduit and whether there is a requirement for a standardised training programme for the novice practitioners.
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11
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A novel biodegradable external mesh stent improved long-term patency of vein grafts by inhibiting intimal–medial hyperplasia in an experimental canine model. Gen Thorac Cardiovasc Surg 2015; 64:1-9. [DOI: 10.1007/s11748-015-0591-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 09/17/2015] [Indexed: 10/23/2022]
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12
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Singh C, Wang X. A new design concept for knitted external vein-graft support mesh. J Mech Behav Biomed Mater 2015; 48:125-133. [PMID: 25916819 DOI: 10.1016/j.jmbbm.2015.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 03/31/2015] [Accepted: 04/01/2015] [Indexed: 11/24/2022]
Abstract
Autologous vein-graft failure significantly limits the long-term efficacy of coronary artery bypass procedures. The major cause behind this complication is biomechanical mismatch between the vein and coronary artery. The implanted vein experiences a sudden increase (10-12 fold) in luminal pressures. The resulting vein over-distension or 'ballooning' initiates wall thickening phenomenon and ultimate occlusion. Therefore, a primary goal in improving the longevity of a coronary bypass procedure is to inhibit vein over-distension using mechanical constriction. The idea of using an external vein-graft support mesh has demonstrated sustained benefits and wide acceptance in experimental studies. Nitinol based knitted structures have offered more promising mechanical features than other mesh designs owing to their unique loosely looped construction. However, the conventional plain knit construction still exhibits limitations (radial compliance, deployment ease, flexibility, and bending stresses) which limit this design from proving its real clinical advantage. The new knitted mesh design presented in this study is based on the concept of composite knitting utilising high modulus (nitinol and polyester) and low modulus (polyurethane) material components. The experimental comparison of the new design with a plain knit design demonstrated significant improvement in biomechanical (compliance, flexibility, extensibility, viscoelasticity) and procedural (deployment limit) parameters. The results are indicative of the promising role of new mesh in restoring the lost compliance and pulsatility of vein-graft at high arterial pressures. This way it can assist in controlled vein-graft remodelling and stepwise restoration of vein mechanical homoeostasis. Also, improvement in deployment limit parameter offers more flexibility for a surgeon to use a wide range of vein diameters, which may otherwise be rendered unusable for a plain knit mesh.
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Affiliation(s)
- Charanpreet Singh
- Australian Future Fibres Research and Innovation Centre, Institute for Frontier Materials, Deakin University, Geelong, Victoria 3216, Australia
| | - Xungai Wang
- Australian Future Fibres Research and Innovation Centre, Institute for Frontier Materials, Deakin University, Geelong, Victoria 3216, Australia; School of Textile Science and Engineering, Wuhan Textile University, Wuhan 430073, China.
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13
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Rivera J, van der Graaf GB, Escudero JR, Bellmunt S, van de Vosse F. A computational fluid dynamics study on hemodynamics for different locations of the distal anastomosis of a bypass nearby a collateral vessel in the femoropopliteal area. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2014; 30:1263-1277. [PMID: 24916477 DOI: 10.1002/cnm.2656] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 05/23/2014] [Accepted: 05/27/2014] [Indexed: 06/03/2023]
Abstract
Revascularization of the femoropopliteal sector is often performed by the placement of a bypass. In this paper, we have studied the effects of hemodynamics on patency of the bypass for different positions of the distal anastomosis close to a collateral artery. Computational fluid dynamics (CFD) are used for this study. The cardiac cycle-averaged wall shear stress (WSS) and oscillation index (OSI) have been analyzed. Low WSS and high OSI may increase the risk of intimal hyperplasia (IH), which may reduce bypass patency. From the CFD simulations, spots of low WSS and high OSI are found within and near the entrance of the collateral artery, near the suture line, at the floor, toe, and heel. We regarded flow ratios of 20:80 and of 35:65. It is found that for the high flow ratio anastomosis located proximal to the collateral artery is clearly more advantageous. However for the low flow ratio anastomosis located distal to the collateral artery seems to be slightly more advantageous, the results are less conclusive. One of the studied flow geometries has been validated by in vitro experiments using a time resolved particle image velocimetry technique. Velocity fields from these experiments are in good agreement with the CFD results.
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Affiliation(s)
- J Rivera
- Departament de Resistència de Materials i Estructures a l'Enginyeria, Universitat Politècnica de Catalunya, Avda. Bases de Manresa 61-73, 08242 Manresa, Spain
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de Fazio Aguiar H, Júnior ACR, de Jesus Piva R, Onoda KA, Miyakawa AA, Krieger JE, Franco DW, Tadini CC. Compatibility of cassava starch films as nitric oxide carrier for potential medical device. J Appl Polym Sci 2014. [DOI: 10.1002/app.41382] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Helena de Fazio Aguiar
- Department of Chemical Engineering; University of São Paulo; Main Campus São Paulo SP, 05508-010 Brazil
| | | | - Renan de Jesus Piva
- Department of Chemical Engineering; University of São Paulo; Main Campus São Paulo SP, 05508-010 Brazil
| | - Kevin Akira Onoda
- Department of Chemical Engineering; University of São Paulo; Main Campus São Paulo SP, 05508-010 Brazil
| | - Ayumi Aurea Miyakawa
- Laboratory of Genetics and Molecular Cardiology; Heart Institute (InCor); University of São Paulo; Campus of São Paulo, 05403-900 São Paulo SP Brazil
| | - Jose Eduardo Krieger
- Laboratory of Genetics and Molecular Cardiology; Heart Institute (InCor); University of São Paulo; Campus of São Paulo, 05403-900 São Paulo SP Brazil
- Department of Cardiopneumology; School of Medicine; University of São Paulo; Campus of São Paulo, 01246-903 São Paulo SP Brazil
| | - Douglas Wagner Franco
- Institute of Chemistry of São Carlos; University of São Paulo; São Carlos SP, 13566-590 Brazil
| | - Carmen Cecilia Tadini
- Department of Chemical Engineering; University of São Paulo; Main Campus São Paulo SP, 05508-010 Brazil
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15
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Abstract
Autogenous vein is the conduit of choice in the surgical creation of bypasses of small-to-medium-caliber vessels in patients with peripheral occlusive arterial disease and will remain so for the near future. The success rate of bypasses using conduits of diameters greater than 6 mm has been excellent, whereas the majority of bypasses using smaller conduits fail within 5 years. In addition, due to a steep increase in rates of diabetes and decreasing cardiovascular mortality rates, increasing challenges are presented by this population. These facts have motivated much of the research in the cardiovascular arena over the past four decades, with improved techniques and new materials. Strategies to improve outcomes include the use of alternative materials including autologous, nonautologous and prosthetic grafts, utilizing different methods for their harvesting and preservation; tissue engineering, using either polymer- or biological-based scaffolds for cell seeding; endovascular methodologies; and gene therapy. This report presents an overview of the several options currently available in the management of patients with peripheral arterial occlusive disease, as well as the ongoing research directed towards the creation of an artificial engineered vessel, discussing experimental work in which endothelial cells have been seeded on different scaffolds and finally the potential application of gene therapy in the field of vascular reconstruction.
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Affiliation(s)
- Luis Leon
- Department of Surgery, Hines VA Hospital, IL 60141, USA.
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16
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Endothelin-1 (ET-1) and vein graft failure and the therapeutic potential of ET-1 receptor antagonists. Pharmacol Res 2011; 63:483-9. [DOI: 10.1016/j.phrs.2010.10.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Revised: 10/27/2010] [Accepted: 10/29/2010] [Indexed: 12/21/2022]
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17
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Carella GS, Stilo F, Benedetto F, David A, Risitano DC, Buemi M, Spinelli F. Femoro-Distal Bypass with Varicose Veins Covered by Prosthetic Mesh. J Surg Res 2011; 168:e189-94. [DOI: 10.1016/j.jss.2010.12.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Revised: 12/06/2010] [Accepted: 12/16/2010] [Indexed: 11/29/2022]
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18
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Muto A, Model L, Ziegler K, Eghbalieh SD, Dardik A. Mechanisms of vein graft adaptation to the arterial circulation: insights into the neointimal algorithm and management strategies. Circ J 2010; 74:1501-1512. [PMID: 20606326 PMCID: PMC3662001 DOI: 10.1253/circj.cj-10-0495] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/17/2023]
Abstract
For patients with coronary artery disease or limb ischemia, placement of a vein graft as a conduit for a bypass is an important and generally durable strategy among the options for arterial reconstructive surgery. Vein grafts adapt to the arterial environment, and the limited formation of intimal hyperplasia in the vein graft wall is thought to be an important component of successful vein graft adaptation. However, it is also known that abnormal, or uncontrolled, adaptation may lead to abnormal vessel wall remodeling with excessive neointimal hyperplasia, and ultimately vein graft failure and clinical complications. Therefore, understanding the venous-specific pathophysiological and molecular mechanisms of vein graft adaptation are important for clinical vein graft management. Of particular importance, it is currently unknown whether there exist several specific distinct molecular differences in the venous mechanisms of adaptation that are distinct from arterial post-injury responses; in particular, the participation of the venous determinant Eph-B4 and the vascular protective molecule Nogo-B may be involved in mechanisms of vessel remodeling specific to the vein. This review describes (1) venous biology from embryonic development to the mature quiescent state, (2) sequential pathologies of vein graft neointima formation, and (3) novel candidates for strategies of vein graft management. Scientific inquiry into venous-specific adaptation mechanisms will ultimately provide improvements in vein graft clinical outcomes.
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Affiliation(s)
- Akihito Muto
- Interdepartmental Program in Vascular Biology and Therapeutics
- the Section of Vascular Surgery, Yale University School of Medicine, New Haven, CT
| | - Lynn Model
- Interdepartmental Program in Vascular Biology and Therapeutics
- the Section of Vascular Surgery, Yale University School of Medicine, New Haven, CT
| | - Kenneth Ziegler
- Interdepartmental Program in Vascular Biology and Therapeutics
- the Section of Vascular Surgery, Yale University School of Medicine, New Haven, CT
| | - Sammy D.D. Eghbalieh
- Interdepartmental Program in Vascular Biology and Therapeutics
- St. Mary's Hospital, Waterbury, CT
| | - Alan Dardik
- Interdepartmental Program in Vascular Biology and Therapeutics
- the Section of Vascular Surgery, Yale University School of Medicine, New Haven, CT
- the VA Connecticut Healthcare System, West Haven, CT
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19
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Desai M, Mirzay-Razzaz J, von Delft D, Sarkar S, Hamilton G, Seifalian AM. Inhibition of neointimal formation and hyperplasia in vein grafts by external stent/sheath. Vasc Med 2010; 15:287-97. [DOI: 10.1177/1358863x10366479] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Synthetic and to a lesser extent vein graft failure is still a major problem in the treatment of peripheral arterial disease, with neointimal hyperplasia being the main cause for graft occlusion in the medium and long term. This review aims to establish the current status of external stents or sheaths in the prevention of intimal hyperplasia in small diameter (< 6 mm) vein grafts.
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Affiliation(s)
- Mital Desai
- Centre for Nanotechnology and Regenerative Medicine, Division of Surgery & Interventional Science, University College London, London, UK, Cardiovascular Haemodynamic Group, University College London, London, UK
| | - Jalaledin Mirzay-Razzaz
- Centre for Nanotechnology and Regenerative Medicine, Division of Surgery & Interventional Science, University College London, London, UK, Cardiovascular Haemodynamic Group, University College London, London, UK
| | - Dirk von Delft
- Christiaan Barnard Division of Cardiothoracic Surgery, University of Cape Town, Cape Town, South Africa
| | - Sandip Sarkar
- Centre for Nanotechnology and Regenerative Medicine, Division of Surgery & Interventional Science, University College London, London, UK
| | - George Hamilton
- Vascular Unit, Royal Free Hampstead NHS Trust Hospital, London, UK
| | - Alexander M Seifalian
- Centre for Nanotechnology and Regenerative Medicine, Division of Surgery & Interventional Science, University College London, London, UK, Cardiovascular Haemodynamic Group, University College London, London, UK,
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20
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Arvela E, Kauhanen P, Albäck A, Lepäntalo M, Neufang A, Adili F, Schmitz-Rixen T. Initial Experience with a New Method of External Polyester Scaffolding for Infrainguinal Vein Grafts. Eur J Vasc Endovasc Surg 2009; 38:456-62. [DOI: 10.1016/j.ejvs.2009.05.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2009] [Accepted: 05/24/2009] [Indexed: 11/29/2022]
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21
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Bahcivan M, Yucel S, Kefeli M, Kamil gol M, Can B, Tahsin keceligil H. Inhibition of vein graft intimal hyperplasia by periadventitial application of hyaluronic acid–carboxymethyl cellulose: An experimental study. SCAND CARDIOVASC J 2009; 42:161-5. [DOI: 10.1080/14017430701747108] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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22
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Abstract
The saphenous vein is the most commonly used graft for revascularization procedures in patients with coronary artery disease and critical limb ischaemia. However, the patency rate of this vessel is poor, with a high proportion of patients requiring further surgery. Early graft occlusion is caused by vasoconstriction or thrombus formation, with later stages of graft failure being due to neointimal formation or atherosclerosis. Apart from its potent constrictor action, endothelin-1 is also a potent proliferative and proinflammatory peptide that is implicated in a number of vascular diseases. The surgical trauma caused during preparation of the saphenous vein as a bypass graft stimulates the release of a number of factors affecting vascular reactivity and structure, including endothelin-1. Endothelin-1 not only constricts animal and human isolated saphenous vein segments but also causes vascular smooth muscle proliferation and neointimal thickening in vitro, actions that are mediated via endothelin (A and B) receptors. Experimentally, the effects of subtype-selective and dual receptor antagonists have been shown to inhibit endothelin-1-mediated constriction and cell proliferation of the saphenous vein. In this review, data supporting a role of endothelin-1 in vein graft occlusion are presented, and the therapeutic potential of endothelin receptor antagonists in improving graft performance is discussed.
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Affiliation(s)
- M R Dashwood
- Royal Free and University College Medical School, London, UK.
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23
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Constrictive external nitinol meshes inhibit vein graft intimal hyperplasia in nonhuman primates. J Thorac Cardiovasc Surg 2008; 136:717-25. [PMID: 18805277 DOI: 10.1016/j.jtcvs.2008.02.068] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2007] [Revised: 01/23/2008] [Accepted: 02/15/2008] [Indexed: 11/21/2022]
Abstract
OBJECTIVE External mesh support of vein grafts has been shown to mitigate the formation of intimal hyperplasia. The aim of the present study was to address the issue of optimal mesh size in a nonhuman primate model that mimics the dimensional mismatch typically encountered between clinical vein grafts and their target arteries. METHODS The effect of mesh size on intimal hyperplasia and endothelial preservation was assessed in bilateral femoral interposition grafts in Chacma baboons (n(Sigma) = 32/n = 8 per mesh size). No mesh support (group I) was compared with external nitinol meshes at three different sizes: loose fitting (group II), 25% diameter constricting (group III), and 50% diameter constricting (group IV). Mesh sizes were seen not only in isolation but also against the background of anastomotic size mismatch at implantation, expressed as quotient of cross-sectional area of host artery to vein graft (Q(C)). RESULTS Significant amounts of intimal hyperplasia were found in group I (Q(C) median 0.20; intimal hyperplasia 6 weeks = 1.63 +/- 0.34 mm(2); intimal hyperplasia 12 weeks = 1.73 +/- 0.5 mm(2)) and group II (Q(C) median 0.25; intimal hyperplasia 6 weeks = 1.96 +/- 1.64 mm(2); intimal hyperplasia 12 weeks = 2.88 +/- 1.69 mm(2)). In contrast, group III (Q(C) median 0.45; intimal hyperplasia 6 weeks = 0.08 +/- 0.13 mm(2); intimal hyperplasia 12 weeks = 0.18 +/- 0.32 mm(2)) and IV (Q(C) median 1.16; intimal hyperplasia 6 weeks = 0.02 +/- 0.03 mm(2); intimal hyperplasia 12 weeks = 0.11 +/- 0.10 mm(2)) showed dramatically suppressed intimal hyperplasia (P < .01) at both time points. Endothelial integrity was only preserved in group IV (P < .05). There were no significant differences in vascularization and inflammation in either interlayer or intergroup comparisons. CONCLUSION By using an animal model that addressed the clinical phenomenon of diameter discrepancy between vein graft and bypassed artery, we could demonstrate that suppression of intimal hyperplasia required constrictive mesh sizes.
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24
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Effect of external stents on prevention of intimal hyperplasia in a canine vein graft model. Chin Med J (Engl) 2007. [DOI: 10.1097/00029330-200712020-00021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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25
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Liao SW, Lu X, Putnam AJ, Kassab GS. A Novel Time-Varying Poly Lactic-Co Glycolic Acid External Sheath for Vein Grafts Designed under Physiological Loading. ACTA ACUST UNITED AC 2007; 13:2855-62. [PMID: 17824833 DOI: 10.1089/ten.2007.0009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Changes in dimensional and mechanical properties of degradable sheaths in poly lactic-co glycolic acid (PLGA) have been researched extensively. Composite PLGA having variable resorption rates in multiple layers under physiological loading has not been reported. Our novel design of a PLGA sheath is composed of 3 layers with different degradation rates (i.e., the innermost layer degrades the fastest, followed by the middle, while the outer layer degrades the slowest). In the presence of physiological luminal pressure, diameter is greater, thickness is less, resorption rate is greater, pore size is greater, and incremental modulus is greater than in nonpressurized sheaths. Furthermore, the ratio of the pore size to the sheath radius affects the dimensional changes of the sheath in the radial direction. In addition to changing the pore size-to-sheath radius ratio, the dimensional changes can be manipulated by choosing different glycolic and lactic acid ratios for the different layers. The application of this novel PLGA design for gradual arterialization of vein grafts is contemplated.
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Affiliation(s)
- Sophia W Liao
- Department of Biomedical Engineering, University of California, Irvine, California, USA
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26
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Jeremy JY, Gadsdon P, Shukla N, Vijayan V, Wyatt M, Newby AC, Angelini GD. On the biology of saphenous vein grafts fitted with external synthetic sheaths and stents. Biomaterials 2006; 28:895-908. [PMID: 17113144 DOI: 10.1016/j.biomaterials.2006.10.023] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2006] [Accepted: 10/10/2006] [Indexed: 02/01/2023]
Abstract
Autologous saphenous vein is used as a conduit to bypass atherosclerotic lesions in both the coronary artery (coronary artery bypass graft surgery [CABG]) and in femoral arteries (infrainguinal bypass graft surgery [IIBS]). Despite the undoubted success and benefits of the procedures, graft failure occurs in 50% of cases within 10 years after surgery. A principal cause of late vein graft failure is intimal and medial hyperplasia and superimposed atherogenesis. Apart from lipid lowering therapy, no intervention has hitherto proved clinically effective in preventing late vein graft failure which clearly constitutes a major clinical and economic problem that needs to be urgently resolved. However, we have studied the effect of external synthetic stents and sheaths in pig models of vein into artery interposition grafting and found them to have a profound effect on vein graft remodelling and thickening. In this review, therefore, we will summarise the mechanisms underlying vein graft failure and how these stents influence these processes and the possible mechanisms involved as well as the application of these devices in preventing vein graft failure clinically.
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27
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Dashwood MR, Savage K, Dooley A, Shi-Wen X, Abraham DJ, Souza DSR. Effect of vein graft harvesting on endothelial nitric oxide synthase and nitric oxide production. Ann Thorac Surg 2006; 80:939-44. [PMID: 16122459 DOI: 10.1016/j.athoracsur.2005.03.042] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2005] [Revised: 03/03/2005] [Accepted: 03/08/2005] [Indexed: 11/21/2022]
Abstract
BACKGROUND Although the saphenous vein is the most commonly used conduit for coronary artery bypass surgery occlusion rates are high, with more than 50% grafts failing within 10 years. Nitric oxide, a potent vasodilator, also inhibits platelet aggregation, thrombus formation and vascular smooth muscle cell proliferation, is implicated in various vascular pathologies, including graft failure. METHODS Saphenous veins were obtained from patients undergoing bypass surgery harvested by conventional methods and with minimal handling, using a "no-touch" technique. Tissue distribution and protein expression of endothelial nitric oxide synthase was compared using immunohistochemistry and Western blot analysis. Nitric oxide generation was assessed using the citrulline assay. RESULTS There was injury to conventional compared with no-touch vein segments, in particular to the lumenal endothelium and tunica adventitia. This injury was accompanied by an absence of endothelial nitric oxide synthase immunostaining at regions of endothelial denudation and damaged adventitial layer of conventional veins and a significant reduction (p < 0.05) in endothelial nitric oxide synthase protein expression. Furthermore, nitric oxide release from conventional tissue extracts was significantly (p < 0.05) lower than no-touch vein segments. CONCLUSIONS Our results show that there is a reduction in endothelial nitric oxide synthase and nitric oxide release in saphenous veins harvested by conventional surgical methods compared with those prepared atraumatically. These observations may influence graft performance.
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Affiliation(s)
- Michael R Dashwood
- Department of Clinical Biochemistry, Royal Free and University College Medical School, Pond Street, London, United Kingdom.
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28
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Shukla N, Rowe D, Hinton J, Angelini GD, Jeremy JY. Calcium and the replication of human vascular smooth muscle cells: studies on the activation and translocation of extracellular signal regulated kinase (ERK) and cyclin D1 expression. Eur J Pharmacol 2005; 509:21-30. [PMID: 15713425 DOI: 10.1016/j.ejphar.2004.12.036] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2004] [Revised: 12/20/2004] [Accepted: 12/24/2004] [Indexed: 10/25/2022]
Abstract
Since the precise role of sarcoplasmic reticular Ca2+ in mediating vascular smooth muscle cells (VSMC) proliferation is unknown, the effect of pre-incubation with thapsigargin on extracellular signal regulated kinase (ERK) activation, the translocation of activated of ERK 1/2 to the nucleus, cyclin D1 expression, the onset of S phase and cytosolic Ca2+ levels were studied. Human saphenous vein VSMCs (hVSMC) were incubated with 10 nM thapsigargin for 24 h followed by stimulation with fetal calf serum and the activation of ERK1/2 and cyclin D1 assessed by western blotting, the intracellular distribution of ERK1/2 using indirect immunofluorescence, the onset of S-phase with the incorporation of bromodeoxyuridine and sarcoplasmic reticular Ca2+ status using FURA-2. Thapsigargin had a marginal effect on ERK1/2 activation only at 5 min and 10 min after stimulation with fetal calf serum. In contrast, the rapid translocation of ERK1/2 to the nucleus was completely blocked by thapsigargin. S phase was delayed by 8 h by thapsigargin which co-incided with the recovery of cytosolic Ca2+ levels and cyclin D1 expression. It is concluded that the inhibitory effect of thapsigargin (depletion of Ca2+ pools) on hVSMC replication is mediated through the inhibition of translocation of activated ERK1/2 to the nucleus and not to the phosphorylation of ERK, per se, which in turn prevents cyclin D1 expression and thus progression of the cell cycle.
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Affiliation(s)
- Nilima Shukla
- Bristol Heart Institute, Department of Cardiac Surgery, University of Bristol, Bristol Royal Infirmary, Bristol BS2 8HW, UK
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29
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Vijayan V, Shukla N, Johnson JL, Gadsdon P, Angelini GD, Smith FCT, Baird R, Jeremy JY. Long-term reduction of medial and intimal thickening in porcine saphenous vein grafts with a polyglactin biodegradable external sheath. J Vasc Surg 2004; 40:1011-9. [PMID: 15557918 DOI: 10.1016/j.jvs.2004.08.047] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVES The development of neointimal hyperplasia with subsequent atherosclerotic deposition has been proposed to cause most late vein graft failures. Our unit has previously demonstrated that placement of a macroporous, loose-fitting polyester external stent prevents neointimal thickening in porcine vein grafts, and has been proposed as a therapeutic strategy to prevent late vein graft failure. To reduce any potential long-term complications of the permanent polyester stent, a study was undertaken to investigate the effect of a biodegradable external stent on porcine vein graft thickening at 1 month and to identify its longer term effects at 6 months. METHODS Bilateral saphenous vein to common carotid artery interposition grafting was performed in Large White pigs (25-32 kg; n = 6 per time course group) according to UK Home Office guidelines. A commercially constructed loose-fitting 8-mm-diameter polyglactin stent was placed externally around the vein graft on one side, and the contralateral side remained unstented to serve as control. The external stent was designed to biodegrade and hence disappear within 90 days. Grafts were left in situ for 1 month in 1 group of animals, and for up to 6 months in the other group, before explantation. Graft morphometric features were assessed with computer-aided planimetry. RESULTS At 1 month the vein grafts fitted with the polyglactin stent demonstrated a statistically significant decrease in neointimal thickening (0.038 mm; interquartile range [IQR], 0.035-0.039 mm) compared with the unstented control grafts (0.13 mm; IQR; 0.11-0.19; P = .0012), and also in medial thickening (0.09 mm; IQR, 0.086-0.093) compared with unsheathed control grafts (0.302 mm; IQR, 0.272-0.414; P = .0012). The 6-month polyglactin stented grafts also demonstrated a statistically significant reduction in neointimal thickening (0.049 mm; IQR, 0.047-0.07; P = .0012) compared with control grafts (0.178 mm; IQR, 0.164-0.19), and also in medial thickening (0.105 mm; IQR, 0.095-0.143) compared with unstented grafts (0.421 mm; IQR, 0.35-0.44; P = .0012, Mann-Whitney U test). CONCLUSION The loose-fitting biodegradable polyglactin external stent reduces porcine vein graft thickening at 1 month, which persists in the long term, even after degradation of the stent itself. This effective removal of the stent may therefore reduce the long-term risks for infection and mechanical complications associated with implanted prosthetic material while still eliciting the primary objective of preventing graft thickening over the long term. Biodegradable external stents therefore have potential advantages over permanent stent material in clinical application. CLINICAL RELEVANCE Arteriovenous bypass graft failure has a huge economic effect on health care resources, and a devastating effect o the patient. The attenuation of vein wall thickening, with subsequent luminal narrowing and occlusion, is a major goal in improving the longevity of the venous graft, to reduce secondary percutaneous and surgical interventions. The biodegradable external stent demonstrated in this study has possible clinical applications in bypass procedures with autogenous venous tissue, and represents a novel approach to ameliorating the problem of intimal hyperplasia that plagues these grafts.
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Affiliation(s)
- Vikram Vijayan
- Vascular Unit, The Bristol Royal Infirmary, Bristol BS2 8HW, UK.
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30
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Jeremy JY, Bulbulia R, Johnson JL, Gadsdon P, Vijayan V, Shukla N, Smith FCT, Angelini GD. A bioabsorbable (polyglactin), nonrestrictive, external sheath inhibits porcine saphenous vein graft thickening. J Thorac Cardiovasc Surg 2004; 127:1766-72. [PMID: 15173735 DOI: 10.1016/j.jtcvs.2003.09.054] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE External, nonrestrictive, macro-porous polyester stents prevent neointima formation in porcine vein grafts and have been proposed as a therapeutic approach to the prevention of late vein graft failure. These stents are nonbiodegradable and therefore may promote long-term foreign body problems including infection and inflammation. The effect of external macro-porous biodegradable (polyglactin) sheaths on neointimal and medial thickening in porcine vein grafts was therefore investigated. METHODS Bilateral saphenous vein-carotid artery interposition grafting was performed in white Landrace pigs (n = 8) with external placement of polyglactin (Vicryl) sheaths (8 mm in diameter) on 1 side, with the contralateral side acting as a control. One month after surgery, grafts were explanted and wall dimensions measured on histological sections using computer-aided planimetry, and an immunocytochemical appraisal was carried out. RESULTS All grafts were patent at explantation. Polyglactin sheaths significantly reduced intimal thickness, medial thickness, and the percentage of proliferating cells compared with unsheathed controls. There was a pronounced accumulation of macrophages, giant cells, endothelial cells, and microvessels within and surrounding the biodegradable sheath compared with controls. CONCLUSIONS A nonrestrictive, biodegradable (polyglactin), external sheath reduces medial and intimal thickening in experimental saphenous vein grafts, possibly through inflammatory cell-mediated angiogenesis. If subsequent long-term studies confirm preservation of this beneficial effect, once the sheath biodegrades, this approach may have an advantage over the permanent polyester stent when applied clinically.
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Affiliation(s)
- Jamie Y Jeremy
- The Bristol Heart Institute, Bristol Royal Infirmary, University of Bristol, Bristol, UK.
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31
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Rivera-Amores J, Houzeaux G. Simulación numérica de flujo sanguíneo: una herramienta útil en cirugía vascular. ANGIOLOGIA 2003. [DOI: 10.1016/s0003-3170(03)74789-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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