Topical vasodilator response in skeletonized internal mammary artery: Is there really a difference?

Coronary artery bypass graft surgery is the gold standard for the treatment of multivessel and left main coronary artery disease. However, there is considerable debate that whether left internal mammary artery (IMA) should be taken as pedicled or skeletonized. This study was conducted to assess the difference in blood flow after the application of topical vasodilator in skeletonized and pedicled IMA.

In this study, each patient underwent either skeletonized (n = 25) or pedicled IMA harvesting (n = 25). The type of graft on each individual patient was decided randomly. Intraoperative variables such as conduit length and blood flow were measured by the surgeon himself. The length of the grafted IMA was carefully determined in vivo, with the proximal and distal ends attached, from the first rib to IMA divergence. The IMA flow was measured on two separate occasions, before and after application of topical vasodilator. Known cases of subclavian artery stenosis and previous sternal radiation were excluded from the study.

The blood flow before the application of topical vasodilator was similar in both the groups (P = 0.227). However, the flow was significantly less in pedicled than skeletonized IMA after application of vasodilator (P < 0.0001). Similarly, the length of skeletonized graft was significantly higher than the length of pedicled graft (P < 0.0001).

Our study signifies that skeletonization of IMA results in increased graft length and blood flow after the application of topical vasodilator. However, we recommend that long-term clinical trials should be conducted to fully determine long-term patency rates of skeletonized IMA.