Johan: I will discuss the leg vein option with my surgeon and cardiologist when they have decided on their bypass recommendation. In the meantime I did however find this article, which says
"In contrast to saphenous vein grafts, the long-term patency rate of arterial bypass conduits is very high, with 85% to 95% of grafts free of significant stenosis at 7 to 10 years.1–6 This is supposed to be because of physiological, anatomic, and hemodynamic characteristics.7 Therefore, the use of arterial conduit is now unanimously accepted as the best choice for surgical revascularization.."
http://circ.ahajournals.org/cgi/content/full/110/11_suppl_1/II-36
and this
"Complete graft occlusion was significantly more common with saphenous-vein grafts (13.6%) than with radial-artery grafts (8.2%). However, an angiographic "string" sign (diffuse narrowing to <1 mm) was evident in significantly more radial-artery (7.0%) than saphenous-vein (0.9%) grafts".
"The grafts are more likely to occlude if there is less flow in the bypassed vessel. Overall, patency was better with radial-artery grafts than with saphenous-vein grafts. The importance of the higher incidence of string signs in the radial-artery grafts is debatable"
http://cardiology.jwatch.org/cgi/content/full/2005/107/1
So it appears the grafts can suffer from both occlusion and stringing if the flow of the bypassed vessel is high, and that occlusion and stringing are two different potential outcomes. This is clearly complex enough to not make any decisions based on "Google research".. but probably an indication it is best to get several professional opinions on the matter.
I would be curious what you find out when you take your CDs to other doctors. In addition to the stentability question perhaps you can ask about the choice of saphenous-vein grafts vs radial-artery grafts.