100 QUESTIONS IN CARDIOLOGY

36 Coronary artery bypass grafting: what is the

case for total arterial revascularisation?

DP Taggart

The clinical and prognostic benefits of coronary artery bypass

grafting (CABG) for certain subgroups of patients with

ischaemic heart disease are well established.^1 Most patients

have three vessel coronary artery disease and the conventional

CABG operation uses a single internal mammary artery (IMA)

and two vein grafts to perform three bypass grafts. This

procedure provides excellent short and intermediate term

outcome but is limited, in the long term, by vein graft failure.

Ten years after CABG 95% of IMA grafts are patent and disease

free whereas three quarters of vein grafts are severely diseased

or blocked.^2

The case for one arterial graft

For over a decade the superior patency of a single IMA over vein

grafts has been known to improve survival and to reduce the

incidence of late myocardial infarction, recurrent angina and the

need for further cardiac interventions.1,2

The case for two arterial grafts

Substantial evidence for the prognostic and clinical benefits of

both IMA grafts has recently been reported in a large study from

the Cleveland clinic.^3 In comparison to the use of a single IMA

graft, use of both IMA grafts resulted in a further significant

improvement in survival (with a reduction in mortality by 10% at

10 years) and a fourfold reduction in the need for reoperation.

Furthermore, these benefits extended across all groups of patients

with a five year life expectancy including “elderly” patients (up to

mid-seventies), and those with diabetes and impaired ventricular

function. The major concern of harvesting both IMA is an increase

in sternal wound complications. This can be avoided by a skele-

tonisation rather than a pedicled technique which leaves

collateral vessels intact on the sternum and allows the safe use of

both IMAs even in diabetic patients.