Morphologic observations after percutaneous transluminal balloon angioplasty of early and late aortocoronary saphenous vein bypass grafts

Abstract

Clinical and morphologic observations from two patients undergoing percutaneous transluminal angioplasty of stenotic aortocoronary saphenous vein bypass grafts early (3 months) and late (56 months) after graft insertion are described. Each patient had one or more clinically successful graft dilations resulting in an angiographic increase in luminal diameter and a decrease in mean trans-stenotic gradient, and each had restenosis of the graft at the site of previous angioplasty within 2 months of dilation. Both operatively excised grafts had diffuse but variable amounts of intimal fibrous thickening and severe narrowing at the previous angioplasty site. The early graft had no evidence of dilation injury, and the intimal thickening consisted solely of fibrocollagenous tissue free of calcific deposits. In contrast, the late graft had a healing intimal dissection at the angioplasty site, and the intimal thickening consisted of atherosclerotic plaque with calcific deposits. Angiographic and morphologic correlations suggest that the mechanism of saphenous vein angioplasty early (less than or equal to 1 year) after insertion is by graft "stretching," while late (greater than 1 year) after insertion it is by atherosclerotic plaque "fracture" similar to that observed in atherosclerotic coronary arteries subjected to angioplasty procedures.

2011 ACCF/AHA Focused Update Incorporated Into the ACC/AHA 2007 Guidelines for the Management of Patients With Unstable Angina/Non–ST-Elevation Myocardial Infarction

“…[817][818][819][820] In addition, post-CABG patients may develop atherosclerosis in their native vessels, and this can lead to UA/NSTEMI. 820,821 However, obstructive lesions are more likely to occur in SVGs (53% within 5 years, 76% at 5 to 10 years, and 92% at greater than 10 years), 822 and there is a high rate of early graft failure in current practice (occlusion in up to one third at 1 year).…”

2012 ACCF/AHA Focused Update Incorporated Into the ACCF/AHA 2007 Guidelines for the Management of Patients With Unstable Angina/Non–ST-Elevation Myocardial Infarction

“…[930][931][932][933] In addition, post-CABG patients may develop atherosclerosis in their native vessels, and this by guest on http://circ.ahajournals.org/ e768 Circulation June 11, 2013…”

Restenosis and its determinants in first and repeat coronary angioplasty

“…The role of platelets in coating a damaged surface immediately after PTCA' 45 " 47 ] and that of thrombus organization' 42 ' has been demonstrated for restenosis in the animal model. Intimal proliferation of smooth muscle cells seems to be the main mechanism of recurrence in man' 40 " 41 " 43 '. It can be triggered by platelet-derived growth factors, but might also be provoked by the balloon injury itself independently of serum factors' 481 and thus even under antiplatelet or anticoagulant drugs.…”