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 transstenotic 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 intimai fibrous thickening and severe narrowing at the previous angioplasty site. The early graft had no evidence of dilation injury, and the intimai thickening consisted solely of fibrocollagenous tissue free of calcific deposits. In contrast, the late graft had a healing intimai dissection at the angioplasty site, and the intimai thickening consisted of atherosclerotic plaque with calcific deposits. Angiographic and morphologic correlations suggest that the mechanism of saphenous vein angioplasty early (≤ 1 year) after insertion is by graft “stretching,” while late (> 1 year) after insertion it is by atherosclerotic plaque “fracture” similar to that observed in atherosclerotic coronary arteries subjected to angioplasty procedures.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine