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Download CAVATAS STUDY 5 years restenosis rate: 30% HR 0.43 (stent
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Stenting:επαναστένωση ISR (intra stent restenosis) Μετεκπαιδευτικό Πρόγραμμα στην Αγγειοχειρουργική - Ενδαγγειακή Χειρουργική ΠΓΝΑ Αττικόν 09-02-2013 Κ. Α. Φίλης Επίκ. Καθηγητής ΕΚΠΑ Definitions ISR can be defined clinically or angiographically. Clinically, it is defined as the presentation of recurrent ischaemia Angiographically, ISR is the presence of >50% diameter stenosis in the stented segment. 50%-70% : moderate Teirstein PS, N Engl J Med, 1997 70%-99% : severe Cellular response to injury • Platelet adherence and degranulation (10-30min) – – – – – Subenthothelial collagen exposure Platelets adherence (αΙΙb βΙΙa, Von Villebrand, Fibronectin) ADP, thromboxane A2, Platelets recruitment (αΙΙb βΙΙIa) Platelets degranulation (PDGF) • Leukocyte, monocytes, macrophages • SMC proliferation and migration (1day – 3months) • Endothelial cell regrowth Diffuse in stent restenosis Initial role of stents : optional to support the dissected ballooned plaque from further dissection-rupture to prevent arterial recoil by their radial force PTA result PTA result Intimal hyperplasia Various ISR rates @ 1 year according to locations Time course of ISR Factors influencing ISR Cardiovascular risk factors Endogenous risk factors Exogenous factors Cardiovascular factors Smoking Diabetes Hyperlipidemia Cardiovascular factors Effect of smoking in ISR Cardiovascular factors Effect of diabetes in ISR P=0.89 (NIDM) P=0.04 (IDM) Endogenous risk factors Genomic Blood flow Plaque Endogenous factors Genomic Endogenous factors Blood flow Endogenous factors Plaque Endogenous factors Endogenous factors Endogenous factors Endogenous factors Exogenous factors Stent Exogenous factors Stent Ευλυγισία Πάχος Ευκολία καθοδήγησης Ακτινική δύναμη Αρχιτεκτονική του πλέγματος Βιοσυμβατότητα Μηχανική αντοχή Αντίσταση στη ρήξη Exogenous factors Stent asymetry Exogenous factors Self expanding V balloon expanded Exogenous factors Cell design Exogenous factors Strut Thickness Exogenous factors Stent fracture Restenosis-Thrombosis Pharmacologic prevention ASA & Heparin ASA & Ticlopidin Restenosis-Thrombosis Pharmacologic prevention Gold standard : Clopidogrel + aspirin Prevention of ISR • • • • Medicines Drug eluting stents Brachytherapy, Cryoplasty Genes Medicines ISR on coronary PTA/stent Reo pro PDGF I antiallergic Induction of vascular atrophy as a novel approach to treating restenosis. A review Seung-Kee Min MDa, Richard D. Kenagy PhDb and Alexander W. Clowes MDb, , Journal of Vascular Surgery Volume 47, Issue 3, March 2008, Pages 662-670 After vascular reconstruction, luminal narrowing is in part caused by intimal thickening, the consequence of endothelial injury and inflammation, smooth muscle cell hyperplasia, and extracellular matrix accumulation. It may be possible to induce these lesions to shrink. This novel approach to the treatment of restenosis is supported by animal experiments and a few clinical observations demonstrating vascular atrophy in response to drugs such as Gleevec (EDGF I). A potential limitation to this approach might be the formation of aneurysms. Drug eluting stents sirolimus results from coronary paclitaxel DES inhibit smooth muscle cells and endothelial cells 1. They inhibit ISR 2. They are more thrombogenic Clinical practice : no benefit in survival, no benefit in MACE, But fewer reinterventions to keep the artery patent DES in cardiac & peripheral arteries Drug eluting stents in peripheral arteries J Endovasc Ther. 2009 Jun;16(3):251-60. Infragenicular stent implantation for below-the-knee atherosclerotic disease: clinical evidence from an international collaborative meta-analysis on 640 patients. Biondi-Zoccai GG, Sangiorgi G, Lotrionte M, Feiring A, Commeau P, Fusaro M, Agostoni P, Bosiers M, Peregrin J, Rosales O, Cotroneo AR, Rand T, Sheiban I. Head-to-head comparisons showed that sirolimus-eluting stents were superior to balloon-expandable bare metal stents in preventing restenosis and increasing primary patency (both p<0.001); sirolimus-eluting stents were also better than paclitaxeleluting stents in terms of primary patency (p<0.001) and repeat revascularizations (p = 0.014). Brachytherapy Gene therapy • Genetically engineered cells secreting a thrombolytic enzyme (tPA) which are topically applied (on the stent). • Major problem : cells are moving away by the blood flow. Conclusions ISR is a stable endothelial reaction to injury STRATEGIES TO INHIBIT ISR systematic Medicines topical DES, Drug eluting balloons Brachytherapy, Cryoplasty Photodynamic therapy Genes