Invited commentary

Abstract

Over the past decade, there has been considerable interest in altering the traditional on-pump approach to sewing coronary artery bypass grafts in a still bloodless field with maximum exposure. Presumed advantages are to avoid the deleterious effects of the heart-lung machine and to allow for a more rapid recovery related to less invasive approaches. These techniques include off-pump coronary artery bypass graft (OPCAB) surgery, minimally invasive direct coronary artery bypass graft (MIDCAB) surgery, and variations using robotic technology. We have also seen the reintroduction of sutureless connectors for both proximal and distal anastomoses. Radial artery grafts and skeletonized internal thoracic arteries are increasingly popular conduits. The introduction of these modalities has been academically stimulating and technically challenging. While perioperative benefit or lack of benefit is readily apparent, the ability to achieve long-term graft patency must be reassessed with each newly introduced technique on an individual and institutional basis. The strength of the manuscript by Hol and colleagues is the pointing out of the need for patency feedback, both short term and long term. The authors present data showing the utility of intraoperative angiography in saving a small number of grafts that were already occluded or likely to occlude early postoperatively. Only 4.2% of grafts were revised. However, there was a significantly higher revision rate in the OPCAB and MIDCAB groups compared with the on-pump group. The authors state that the higher OPCAB and MIDCAB revision rates may be related to a learning curve. However, the study was done over an 8-year period, and presumably some of the OPCAB and MIDCAB procedures were performed after a significant amount of experience was gained. Therefore, it is doubtful that a learning curve is the entire reason for the higher revision rate in these subgroups. Although patency rates at 1-year follow-up were not statistically different, there was a concerning trend toward lower patency rates in the OPCAB group for both saphenous vein grafts and left internal thoracic artery grafts. The 90% 1-year patency for left internal thoracic artery to left anterior descending artery grafts is less than acceptable. This patency rate was in the face of 9.4% of the original left internal thoracic artery to left anterior descending artery grafts requiring revision. This manuscript adds to the concern that long-term patency of OPCAB grafts may be less than with on-pump revascularization. I congratulate the authors on their use of angiographic control to compare newly introduced techniques with the traditional approach. This approach should be standard of care as we continue our attempts to improve the outcomes of surgical coronary revascularization.