The case for three arterial grafts
Several arteries have been proposed as the third arterial graft and
the most widely used is the radial artery. The radial artery is a
versatile conduit, which can be harvested easily and safely, has
handling characteristics superior to those of other arterial grafts
and comfortably reaches any coronary target. For the patient it
offers the prospect of superior graft patency compared to saphenous
vein grafts^4 as well as improved wound healing. The potential
impact of the radial artery on survival is not yet established as it has
only been in widespread use for five years.
Finally, many patients are interested to know “how long grafts
are likely to last”. This may be viewed most helpfully in terms of
event rates, rather than physical lack of occlusion of a graft:
“ischaemic event rate” (5% per year) and cardiac mortality
(2–2.5% per year). A recurrent “event” (death, MI or recurrence of
angina) occurs in 25% of surgically treated patients in <5 years,
and 50% at 10 years.
In summary, the use of arterial grafts offers substantial short and
long term clinical and prognostic benefits. In particular the use of
both IMA grafts significantly reduces mortality and the need for
re-operation. Current evidence suggests that the superior patency
of arterial grafts also reduces perioperative mortality by reducing
perioperative myocardial infarction. This is particularly true in
patients with smaller or more severely diseased coronary arteries
(females, diabetics, Asian background) where discrepancy
between the size of vein grafts and coronary vessels leads to “run-
off” problems and a predisposition to graft thrombosis. Careful
harvesting of both IMAs can be performed even in diabetic
patients without an increase in wound healing problems. Relative
contraindications to arterial grafts are patients who are likely to
require significant inotropic support in the postoperative period
(because of the risk of graft vasoconstriction) or those with
severely impaired ventricular function (ejection fraction less than
25%) and limited life expectancy.
RReeffeerreenncceess
1 Yusuf S, Zucker D, Peduzzi P et al. Effect of coronary artery bypass graft
surgery on survival: overview of 10-year results from randomised
trials by the Coronary Artery Bypass Graft Surgery Trialists
Collaboration. Lancet 1994; 334444 : 563–70.
2 Nwasokwa ON. Coronary artery bypass graft disease. Ann Intern Med
1995; 112233 : 528–45.