Spontaneous rupture of autogenous saphenous vein graft in bypass surgery for peripheral arterial disease possibly associated with collagen disease

We encountered two cases of spontaneous rupture of a saphenous vein bypass graft for lower-leg peripheral arterial disease possibly associated with collagen disease. Rupture occurred 5?and 14 days postoperatively. Neither case had any signs of infection, graft degeneration, or evident injury, but both were associated with collagen disease diagnosed at another hospital. We believe that an association with collagen disease might have contributed to vein wall fragility in the present cases.