How long does a bypass heart graft last?

Multifactorial : Average lifespan of a saphenous vein graft is 7-8 years. 50% open in 10 years. Of an artery usually internal mammary 90% at 10 years. Above depend on severity of disease, surgeon technique and skills, morbidities associated with the patient, quality of the graft, quality of follow up, rehabilitation process, changes in life style, patient responsibility with care.