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Krishnan P, Purushothaman KR, Purushothaman M, Tarricone A, Chen S, Singla S, Purushottam B, Kini A, Sharma S, Moreno PR. Histological features of restenosis associated with paclitaxel drug-coated balloon: implications for therapy. Cardiovasc Pathol 2019; 43:107139. [PMID: 31437716 DOI: 10.1016/j.carpath.2019.06.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 06/17/2019] [Accepted: 06/18/2019] [Indexed: 11/17/2022] Open
Abstract
PURPOSE To investigate the cellular and extracellular changes induced by drug-coated balloons (DCB) in the treatment of superficial femoral artery (SFA) restenosis, and to compare histopathological features with those observed after plain old balloon angioplasty (POBA) from the same patients. METHODS AND RESULTS Plaque samples for five patients with SFA restenosis (first-time) after POBA were collected using atherectomy and DCB. These samples constitute the POBA restenosis group. The same five patients developed recurrent restenosis (RR) after DCB, at the same intervention site. These SFA-RR lesions were again treated using atherectomy and POBA. These samples constitute the DCB restenosis group. DCB restenosis group plaques showed significant reduction in neointima, smooth muscle cells, fibroblast densities, and Ki67 index; and increase in caspase 3, features of apoptosis and type III collagen deposition in comparison to the POBA restenosis group. CONCLUSION Plaque tissue from the DCB restenosis group show reductions in neointimal thickness, cellularity, and cellular proliferation, along with increased apoptosis, and Type III collagen content. These results suggest a different mechanistic pathway for DCB restenosis, in which neointimal proliferation is reduced but reparative fibrosis is increased. The treatment for SFA-RR after DCB may therefore benefit from different forms of therapy including scaffolding, rather than recurrent anti-proliferative therapy.
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Affiliation(s)
- Prakash Krishnan
- The Zena and Michael A. Weiner Cardiovascular Institute and the Marie-Josée and Henry R. Kravis Cardiovascular Health Center, Department of Medicine/Cardiology, Icahn School of Medicine at Mount Sinai, New York, NY.
| | - K-Raman Purushothaman
- The Zena and Michael A. Weiner Cardiovascular Institute and the Marie-Josée and Henry R. Kravis Cardiovascular Health Center, Department of Medicine/Cardiology, Icahn School of Medicine at Mount Sinai, New York, NY.
| | - Meerarani Purushothaman
- The Zena and Michael A. Weiner Cardiovascular Institute and the Marie-Josée and Henry R. Kravis Cardiovascular Health Center, Department of Medicine/Cardiology, Icahn School of Medicine at Mount Sinai, New York, NY.
| | - Arthur Tarricone
- The Zena and Michael A. Weiner Cardiovascular Institute and the Marie-Josée and Henry R. Kravis Cardiovascular Health Center, Department of Medicine/Cardiology, Icahn School of Medicine at Mount Sinai, New York, NY.
| | - Simon Chen
- The Zena and Michael A. Weiner Cardiovascular Institute and the Marie-Josée and Henry R. Kravis Cardiovascular Health Center, Department of Medicine/Cardiology, Icahn School of Medicine at Mount Sinai, New York, NY.
| | - Sandeep Singla
- The Zena and Michael A. Weiner Cardiovascular Institute and the Marie-Josée and Henry R. Kravis Cardiovascular Health Center, Department of Medicine/Cardiology, Icahn School of Medicine at Mount Sinai, New York, NY.
| | | | - Annapoorna Kini
- The Zena and Michael A. Weiner Cardiovascular Institute and the Marie-Josée and Henry R. Kravis Cardiovascular Health Center, Department of Medicine/Cardiology, Icahn School of Medicine at Mount Sinai, New York, NY.
| | - Samin Sharma
- The Zena and Michael A. Weiner Cardiovascular Institute and the Marie-Josée and Henry R. Kravis Cardiovascular Health Center, Department of Medicine/Cardiology, Icahn School of Medicine at Mount Sinai, New York, NY.
| | - Pedro R Moreno
- The Zena and Michael A. Weiner Cardiovascular Institute and the Marie-Josée and Henry R. Kravis Cardiovascular Health Center, Department of Medicine/Cardiology, Icahn School of Medicine at Mount Sinai, New York, NY.
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2
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DeSart K, O'Malley K, Schmit B, Lopez MC, Moldawer L, Baker H, Berceli S, Nelson P. Systemic inflammation as a predictor of clinical outcomes after lower extremity angioplasty/stenting. J Vasc Surg 2015; 64:766-778.e5. [PMID: 26054584 DOI: 10.1016/j.jvs.2015.04.399] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 04/18/2015] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The activation state of the systemic inflammatory milieu has been proposed as a critical regulator of vascular repair after injury. We evaluated the early inflammatory response after endovascular intervention for symptomatic peripheral arterial disease to determine its association with clinical success or failure. METHODS Blood samples were obtained from 14 patients undergoing lower extremity angioplasty/stenting and analyzed using high-throughput gene arrays, multiplex serum protein analyses, and flow cytometry. RESULTS Time-dependent plasma protein and monocyte phenotype analyses demonstrated endovascular revascularization had a modest influence on the overall activation state of the systemic inflammatory system, with baseline variability exceeding the perturbations induced by the intervention. In contrast, specific time-dependent changes in the monocyte genome are evident in the initial 28 days, predominately in those genes associated with leukocyte extravasation. Investigating the relationship between inflammation and the 1-year success or failure of the intervention showed no single plasma protein was correlated with outcome, but a more comprehensive cluster analysis revealed a clear pattern of protein expression that was closely related to the clinical phenotype. Corresponding examination of the monocyte genome identified a gene subset at 1 day postprocedure that was predictive of clinical outcome, with most of these genes active in cell-cycle signaling. CONCLUSIONS Although the global influence of angioplasty/stenting on systemic inflammation was modest, circulating cytokine and monocyte genome analyses support a pattern of early inflammation that is associated with ultimate intervention success vs failure. Molecular profiles incorporating genes involved in monocyte cell-cycle progression and homing, or proinflammatory cytokines, or both, offer the most promise for the development of class prediction tools for clinical application.
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Affiliation(s)
- Kenneth DeSart
- Department of Surgery, University of Florida College of Medicine, Gainesville, Fla
| | - Kerri O'Malley
- Department of Surgery, University of Florida College of Medicine, Gainesville, Fla
| | - Bradley Schmit
- Department of Surgery, University of Florida College of Medicine, Gainesville, Fla
| | - Maria-Cecilia Lopez
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Fla
| | - Lyle Moldawer
- Department of Surgery, University of Florida College of Medicine, Gainesville, Fla
| | - Henry Baker
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Fla
| | - Scott Berceli
- Department of Surgery, University of Florida College of Medicine, Gainesville, Fla; Malcom Randall VA Medical Center, Gainesville, Fla
| | - Peter Nelson
- Division of Vascular and Endovascular Surgery, University of South Florida Morsani College of Medicine, Tampa, Fla; James A. Haley VA Medical Center, Tampa, Fla.
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3
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Parmar JH, Aslam M, Standfield NJ. Significant Prostacyclin/Thromboxane Level Imbalance after Lower Limb Arterial Angioplasty: A Possible Platelet Function Alteration. J Vasc Interv Radiol 2010; 21:1354-8. [DOI: 10.1016/j.jvir.2010.05.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2009] [Revised: 04/15/2010] [Accepted: 05/07/2010] [Indexed: 10/19/2022] Open
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4
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Wahlgren CM, Frebelius S, Swedenborg J. Inhibition of neointimal hyperplasia by a specific thrombin inhibitor. SCAND CARDIOVASC J 2009; 38:16-21. [PMID: 15204242 DOI: 10.1080/14017430310016513] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE Restenosis secondary to neointimal hyperplasia remains the major limiting factor after vascular interventions. Thrombin generated in high concentrations at the site of vascular injury plays a central role in thrombosis and hemostasis. Thrombin has also been implicated as a mitogen for smooth muscle cell proliferation that contributes to restenosis. This study was designed to determine the effects of a specific thrombin inhibitor on neointimal hyperplasia after balloon injury in a rat carotid artery model. DESIGN A total of 47 male Sprague-Dawley rats were divided into five groups. All groups underwent balloon injury of the left carotid artery. A specific thrombin inhibitor, inogatran, was given in four different regimens: low and high dose injections, short-term infusion for 3 h, and long-term infusion for 1 week. After 2 weeks the animals were killed and the carotid neointima/media area ratio and the luminal narrowing were calculated. RESULTS All treatments significantly reduced the neointimal hyperplasia. Inogatran given as a long-term infusion for 1 week had the lowest neointima/media ratio compared with the other groups. The percentage of lumen narrowing was also significantly lower in all treatment groups compared with the control group. CONCLUSION A specific direct thrombin inhibitor, inogatran, reduces neointimal hyperplasia after arterial injury in rats. A more prolonged administration of the thrombin inhibitor gave a further reduction of the neointimal hyperplasia. It seems that inhibition of thrombin activity is not only important early after injury, but also later. This could have clinical implications in the treatment of restenosis and needs to be further evaluated.
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5
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Nickson CM, Doherty PJ, Williams RL. Novel polymeric coatings with the potential to control in-stent restenosis--an in vitro study. J Biomater Appl 2008; 24:437-52. [PMID: 19033327 DOI: 10.1177/0885328208099338] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Restenosis following percutaneous coronary intervention (PCI) is a considerable problem in long-term performance of cardiovascular stents, with a functional endothelial cell monolayer being important in its prevention. This study evaluates the influence of polymer coatings on human aortic endothelial cells (HAEC) and coronary artery smooth muscle cells (HCASMC) in vitro, in terms of morphology, cell number, and phenotype. It was demonstrated that the polymer coatings can be tailored to enhance adhesion and growth of HAECs whilst suppressing that of HCASMCs. It is concluded that one of the polymer coatings (BTL 01015) shows potential as a stent coating to enhance re-endothelialization.
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Affiliation(s)
- C M Nickson
- Clinical Engineering, School of Clinical Sciences, University of Liverpool Duncan Building, Daulby Street, Liverpool L693GA.
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6
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Smeets L, Ho GH, Moll FL. Remote endarterectomy for occlusive iliac and superficial femoral artery disease. Future Cardiol 2007; 3:43-51. [PMID: 19804206 DOI: 10.2217/14796678.3.1.43] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Today's patients increasingly desire a low-risk procedure with rapid return to functional status following surgery. Many patients actively seek a minimally invasive option. During the last decade, minimally invasive surgical and radiological procedures emerged from their infancy to become an integral part of the treatment strategy in both peripheral arterial occlusive disease and aneurysmal arterial disease. The trend towards restoration of luminal patency, using the vessel itself as a conduit, can also be termed restorative intervention. As radiological percutaneous transluminal angioplasty has thus far proven unsuccessful in the long term for iliac and femoropopliteal occlusive lesions exceeding 10 cm, a new endovascular surgical procedure has been developed. A modification to the original ringstripper, used in semiclosed endarterectomy, was made to enable the technique of remote endarterectomy.
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Affiliation(s)
- Luuk Smeets
- Twenteborg Hospital, Department of Surgery, Zilvermeeuw 1, 7609 PP Almelo, The Netherlands.
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7
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Wong S, Appleberg M, Lewis DR. Antiplatelet therapy in peripheral occlusive arterial disease. ANZ J Surg 2006; 76:364-72. [PMID: 16768698 DOI: 10.1111/j.1445-2197.2006.03725.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND Antiplatelet therapy (APT) in patients with peripheral occlusive arterial disease (POAD) may reduce cardiovascular (CV) morbidity and mortality by inhibiting atherothrombosis. This article reviews the current evidence for APT in patients with stable POAD and in patients undergoing revascularization procedures for POAD. METHODS A Medline and Pubmed literature search (January 1966 to February 2003) was conducted to identify articles relating APT and POAD. Manual cross referencing was also used. RESULTS AND CONCLUSIONS Meta-analyses suggest that APT (most commonly aspirin) in patients with stable POAD significantly reduces the incidence of nonfatal stroke, myocardial infarction and CV death. However, this conclusion is based on subset analysis of data predominantly involving patients with coronary and cerebrovascular atherosclerosis. There is a little direct evidence for the use of aspirin in patients with isolated POAD, but in practice, aspirin remains the most commonly used antiplatelet agent as high rates of coronary and cerebrovascular diseases are observed in this patient population. For patients with POAD without additional indicators of vascular risk, the protective effect of aspirin is unclear and dependent on the balance of risks and benefits in the individual patient. For patients undergoing peripheral revascularization, ticlopidine and aspirin in combination with dipyridamole are effective in maintaining patency after bypass procedures and following angioplasty/femoral endarterectomy. The efficacy of thienopyridines in peripheral angioplasty is uncertain, and the optimum timing and duration of APT relative to intervention are not known.
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Affiliation(s)
- Shen Wong
- Department of Vascular Surgery, Sydney University, The Royal North Shore Hospital, Sydney, New South Wales, Australia
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8
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Pai M, Jamal W, Mosse A, Bishop C, Bown S, McEwan J. Inhibition of in-stent restenosis in rabbit iliac arteries with photodynamic therapy. Eur J Vasc Endovasc Surg 2005; 30:573-81. [PMID: 16125418 DOI: 10.1016/j.ejvs.2005.07.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2005] [Accepted: 07/05/2005] [Indexed: 11/18/2022]
Abstract
OBJECTIVES Photodynamic therapy (PDT, the combination of light with a photosensitising drug in the presence of oxygen) inhibits restenosis after angioplasty without stenting. This study assesses the potential of PDT for prevention of in-stent re-stenosis. DESIGN AND METHODS Normal rabbits were given the photosensitising agent 5-aminolaevulinic acid (ALA) 60 mg/kg, 3 h prior to endovascular illumination of the iliac artery (635 nm at 50 J/cm(2)) either immediately before or after deployment of an oversized (3 mm diameter) stent. PDT treated arteries were retrieved 3 or 28 days later and assessed for cell counts and vascular morphometry. Control arteries (stent but no PDT) were examined at 28 days. RESULTS There were no adverse events and all vessels were patent at the end of the study. At 3 days there was almost complete medial cell ablation when light was delivered before stent deployment (17+/-1 cells/hpf), with little effect when illumination followed stent deployment (184+/-17 cells/hpf, p<0.0001). Twenty-eight days after PDT, the neointimal areas were 1.41+/-0.52 mm(2) (stent with no PDT), 1.24+/-0.54 mm(2) (light after stent) and 0.60+/-0.21 mm(2) (light before stent) (p=0.004). CONCLUSIONS PDT before stent deployment caused almost complete medial cell ablation at 3 days with inhibition of in-stent restenosis at 28 days. PDT is worthy of further study as an adjuvant to percutaneous intervention in patients with vascular disease.
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MESH Headings
- Aminolevulinic Acid/administration & dosage
- Aminolevulinic Acid/therapeutic use
- Animals
- Arterial Occlusive Diseases/surgery
- Blood Vessel Prosthesis Implantation/instrumentation
- Disease Models, Animal
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/pathology
- Graft Occlusion, Vascular/drug therapy
- Graft Occlusion, Vascular/pathology
- Iliac Artery
- Injections, Intra-Arterial
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/pathology
- Photochemotherapy/methods
- Photosensitizing Agents/administration & dosage
- Photosensitizing Agents/therapeutic use
- Prosthesis Failure
- Rabbits
- Stents
- Treatment Outcome
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Affiliation(s)
- M Pai
- The Royal Free and University College London Medical School, London, UK
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9
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Wahlgren CM, Pekkari K. Elevated Thioredoxin After Angioplasty in Peripheral Arterial Disease. Eur J Vasc Endovasc Surg 2005; 29:281-6. [PMID: 15694802 DOI: 10.1016/j.ejvs.2004.12.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/16/2004] [Indexed: 10/26/2022]
Abstract
OBJECTIVE Oxidative stress and inflammation in the vessel wall may play important roles in the development of restenosis after angioplasty. Reactive oxygen species have been suggested to mediate the proliferative phenotype in smooth muscle cells. The role of the redox-active proteins, thioredoxin and glutaredoxin, after angioplasty in patients with peripheral arterial disease has never been assessed before. Circulating thioredoxin impairs the chemotactic response to local sites of inflammation and administration of human recombinant Trx has been shown to attenuate ischemic reperfusion injury. METHODS AND RESULTS Patients with peripheral arterial disease undergoing angioplasty were included in this observational study. Plasma levels of thioredoxin and glutaredoxin were analysed before and 1, 4 and 24 h, and 1 week after angioplasty. Plasma levels of thioredoxin were significantly elevated 4 h after angioplasty [2.3 ng/ml (0.5-14), p=0.02] and returned to baseline within 24 h [1.1 ng/ml (0.5-3.1), p=0.02]. There may also exist an association between patients with elevated levels of thioredoxin after angioplasty and decreased rate of restenosis at follow-up angiography after 6 months. There were no changes in plasma levels of glutaredoxin after angioplasty. CONCLUSION These findings provide a new insight to the role of thioredoxin in the complex process of vascular injury and restenosis in patients with peripheral arterial disease, suggesting thioredoxin both as a marker of oxidative stress and as a therapeutic agent.
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Affiliation(s)
- C-M Wahlgren
- Department of Vascular Surgery, Karolinska University Hospital, Stockholm, Sweden.
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10
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Johst U, Betsch A, Wiskirchen J, Schöber W, Vonthein R, Rinkert N, Kehlbach R, Claussen CD, Duda SH. All-trans and 9-cis retinoid acids inhibit proliferation, migration, and synthesis of extracellular matrix of human vascular smooth muscle cells by inducing differentiation in vitro. J Cardiovasc Pharmacol 2003; 41:526-35. [PMID: 12658053 DOI: 10.1097/00005344-200304000-00004] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The aim of this study was to evaluate the effects of 9-cis retinoid acid (9-cis RA) and all-trans RA (ATRA) on proliferation, migratory ability, synthesis of extracellular matrix, intracellular signal transduction, and differentiation of human aortic smooth muscle cells (haSMCs) in vitro. Changes of cell proliferation following incubation with RAs in different doses (10-6 M, 10-7 M, and 10-8 M) were determined directly by proliferation kinetics and indirectly by bromodeoxyuridine enzyme-linked immuno sorbant assays and colony-formation assays. The migratory ability of haSMCs was examined with the help of migration assays. The production of the extracellular matrix protein tenascin was explored by immunostaining. The amounts of total p44/p42 mitogen-activated protein kinases (MAPKs) and their phosphorylated forms were detected with the help of Western blots. To judge the state of differentiation of haSMCs, cell cycle distribution and the pattern of alpha-actin were analyzed. Both RAs clearly inhibited the proliferation of haSMCs in a dose-dependent manner. 9-cis RA had a tendency to be more effective than ATRA. After treatment with RAs, the migratory ability was especially reduced during stimulation with platelet-derived growth factor (PDGF) and the synthesis of tenascin decreased. Although the total p44/p42 MAPKs were downregulated, the amounts of activated forms increased markedly in the cells incubated with RAs and particularly stimulated with PDGF. The cell-cycle analysis demonstrated an increased G1-phase, complemented by a stronger expression of alpha-actin after treatment. 9-cis RA especially has the potential to inhibit the proliferation, migration, and synthesis of extracellular matrix of haSMCs by inducing differentiation in vitro.
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Affiliation(s)
- Ursula Johst
- Department of Diagnostic Radiology, Eberhard-Karls University, Tübingen, Germany.
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11
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Cassar K, Bachoo P, Brittenden J. The role of platelets in peripheral vascular disease. Eur J Vasc Endovasc Surg 2003; 25:6-15. [PMID: 12525805 DOI: 10.1053/ejvs.2002.1795] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Platelets play a major role in acute ischaemic syndromes and peripheral vascular disease. They are involved in the development and progression of atherosclerosis, native vessel and graft thrombosis. They have a central role in the development of restenosis and reocclusion after peripheral percutaneous transluminal angioplasty. Antiplatelet therapy has been shown to be beneficial in patients undergoing peripheral vascular surgery or radiological intervention. Yet current routine therapy, namely aspirin and dipyridamole are limited in their mode of action and efficacy. Recent developments in the understanding of platelet function has led to the development of new more potent drugs such as clopidogrel. Combination of drugs and more specific investigation of individual platelet function may well result in improved bypass and angioplasty patency rates. The results of proposed large randomised controlled trials on the role and safety of aspirin and clopidogrel are awaited with interest. Given the importance of platelets in peripheral vascular disease highlighted in this review, achieving an optimal safe anti-platelet effect for each patient with peripheral vascular disease should be the target of future research.
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Affiliation(s)
- K Cassar
- Vascular Unit, Ward 36, Aberdeen Royal Infirmary and University of Aberdeen, Aberdeen, Scotland
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12
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Heckenkamp J, Adili F, Kishimoto J, Koch M, Lamuraglia GM. Local photodynamic action of methylene blue favorably modulates the postinterventional vascular wound healing response. J Vasc Surg 2000; 31:1168-77. [PMID: 10842154 DOI: 10.1067/mva.2000.106491] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PURPOSE Photodynamic therapy (PDT), the light activation of photosensitizers to produce free radicals, is known to inhibit experimental intimal hyperplasia (IH). However, its clinical application has been limited by the lack of a suitable approach and a clinically appropriate photosensitizer. The aim of this study was to determine the effectiveness of a clinical approach for PDT, while testing its ability to favorably modulate the vascular wound healing response. METHODS Rat carotid arteries were balloon-injured (BI), and for PDT, the arteries were irradiated with thermoneutral laser light (lambda = 660 nm, 100 J/cm(2)) after the photosensitizer methylene blue (MB) was delivered locally. Control rats included BI alone and MB after BI alone. Arteries were analyzed after 2 weeks with morphometric evaluation (n = 6) and in situ hybridization for versican and procollagen type I gene expression (digitized image pixel analyses, n = 3). RESULTS No IH developed in PDT-treated arteries (0 +/- 0 mm(2); compared with BI, 0.192 +/- 0.006 mm(2); P <.0001). The diameters remained unchanged (PDT, 0.95 +/- 0.04 mm; BI, 0.94 +/- 0.05 mm; uninjured artery, 0.91 +/- 0.06 mm). Arterial injury resulted in an increase of versican and procollagen type I messenger RNA (mRNA) in the adventitia and neointima. In the repopulating cells of the adventitia after PDT, there was a significant decrease in versican mRNA (% of positive pixels per high-power field: PDT, 1.13% +/- 0.39%; BI, 2.93% +/- 0.61%; P <.02), but not in procollagen type I mRNA. CONCLUSION The decrease of versican mRNA expression of repopulating cells after PDT reflects favorable healing on a molecular level. Site-specific delivery of MB, a clinically appropriate photosensitizer, followed by PDT represents a suitable method to promote favorable healing after balloon intervention and further supports its role for inhibiting postinterventional restenosis.
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Affiliation(s)
- J Heckenkamp
- Division of Vascular Surgery and Wellman Laboratories of Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston 02114, USA
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