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| {{SI}}
| | #redirect[[Saphenous Vein Graft]] |
| {{WikiDoc Cardiology Network Infobox}}
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| {{CMG}}<br/>
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| '''Associate Editors-In-Chief:''' Jason C. Choi, M.D., Xin Yang, M.D.
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| {{Editor Help}}
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| ==Background==
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| Coronary artery revascularization with [[saphenous veins]] ([[saphenous vein grafts]] or [[SVGs]]) has become a modern surgical standard for the treatment of [[coronary artery disease]]. This technique can be employed when a native [[coronary artery]] is blocked, thus causing a reduction or obstruction in [[blood flow]]. [[Cardiac surgeons]] use the sutured graft to connect the [[aorta]] to the coronary artery beyond the area of obstruction, so that [[blood flow]] may resume.
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| Despite their ability to restore [[blood flow]], SVGs commonly encounter [[stenosis]] problems. The incidence of SVG stenosis is 15-30% one year after surgery, and it increases to 50% 10 years after surgery. Several factors contribute to [[stenosis]] of [[saphenous vein grafts]], including [[intimal hyperplasia]], [[plaque]] formation, and graft remodeling. Additionally, arterialization of the graft accelerates [[atherosclerosis]]. Furthermore, [[atheroma]] found in SVGs are more friable (easily break into small pieces) and more prone to [[thrombus]] than [[plaques]] found in native vessels. Another reason why SVGs are more susceptible to [[thrombotic occlusion]] is that they lack side branches.
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| Although intervention on a chronic total occlusion of an SVG may seem like an effective treatment strategy, it is best avoided.
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| ==Goals of Treatment==
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| Primarily, the goal should be to detect and treat a SVG [[stenosis]] early in the development of [[ischemia]] while the SVG is still [[patency|patent]]. As long as the SVG is not completely [[occlusion|occluded]], intervention can be performed.
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| Two additional overall goals of treating [[SVG]] [[stenosis]] include the resolution of symptomatic [[ischemia]] and the prevention/treatment of [[embolism|distal embolization]].
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| ==Treatment Options==
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| There are many different choices to consider when deciding the most appropriate treatment for SVG [[stenosis]], including [[PTCA]], [[PCI]] with [[bare metal stent|bare metal]] or [[drug-eluting stents]], PCI with covered [[stents]], embolic protection devices, [[debulking]]/[[thrombus]] removal, and surgical [[revascularization]].
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| ===Percutaneous Transluminal Coronary Angioplasty (PTCA)===
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| [[PTCA]] has high initial [[revascularization]] success rates in the treatment of SVG [[stenosis]]. However, it is also associated with high rates of periprocedural complications, including acute vessel closure secondary to [[dissection]] and in-situ [[thrombosis]]. Additional complications include [[embolism|distal embolization]] and [[no reflow]], which can lead to periprocedural [[infarction]].
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| In modern [[interventional cardiology]], PTCA is not often used as the sole means of treatment for SVG [[stenosis]]. Instead, [[stenting]] has become the cornerstone of treatment, while the use of PTCA has been limited to pre-dilation and post-dilation.
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| ===PCI with Bare Metal Stents (BMS) or Drug-eluting Stents (DES)===
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| Most current vein graft treatment strategies utilize PCI with stents ([[BMS]] or [[DES]]), since stenting is a superior treatment when compared to [[PTCA]] alone. As demonstrated in the Saphenous Vein De Novo (SAVED) Trial, the use of [[stents]] is associated with higher [[revascularization]] success rates, decreased [[restenosis]] rates, and improved clinical outcomes when compared to [[PTCA]]. <ref name="pmid9287229">{{cite journal |author=Savage MP, Douglas JS, Fischman DL, ''et al.'' |title=Stent placement compared with balloon angioplasty for obstructed coronary bypass grafts. Saphenous Vein De Novo Trial Investigators |journal=N. Engl. J. Med. |volume=337 |issue=11 |pages=740–7 |year=1997 |month=September |pmid=9287229 |doi= |url=}}</ref> Generally, [[DES]] are preferred over [[BMS]], since [[DES]] are associated with reduced rates of [[restenosis]] and target vessel [[revascularization]].
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| Despite their higher success rates, stents are not immune to [[restenosis]]. Predictors for [[restenosis]] include long [[stent]] length, multiple [[stents]], overlapping [[stents]], smaller vessel size, [[diabetes mellitus]], and [[stenosis]] at the coronary or aortic [[anastomosis]].
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| ===PCI with Covered Stents===
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| Theoretically, [[stents]] covered with a polymer membrane would have higher success rates than standard [[BMS]] and [[DES]]. One would expect covered stents to effectively trap friable [[atheroma]] and isolate the graft [[Lumen (anatomy)|lumen]] from the diseased wall, thereby reducing incidence of [[restenosis]], distal [[embolization]], and [[no reflow]] in comparison to traditional [[stents]].
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