Pedicled better than skeletonized technique for mammary artery grafting in CABG surgery: JAMA

Canada: Harvesting of the internal mammary artery during CABG surgery using a pedicled technique improved outcomes at 1 to 2 years compared with the skeletonized technique, show findings from post hoc analysis of the COMPASS trial.

According to the study, published in the journal JAMA Cardiology, the use of the skeletonized technique led to a higher rate of graft occlusion and worst clinical outcomes. 

Multiple arterial grafting (MAG) has been shown to provide a survival advantage in patients undergoing coronary artery bypass grafting (CABG) versus the revascularization strategies involving a left internal mammary artery (LIMA) to the LAD and saphenous vein grafts for the remaining targets, especially in a patient population whose life expectancy is greater than 10 years. When two internal mammary arteries (IMAs) are utilized rather than a LIMA along with a radial graft, the benefits of MAG appear to be more pronounced. Despite this, many surgeons refuse to use IMA grafts owing to the fear of sternal wound-healing complications, which have been clearly described especially in obese, diabetic, and female patients.

In cases where a skeletonized technique is employed for IMA harvesting, the wound-healing appears to be partially mitigated. The decreased tissue damage on the inner surface of the sternum achieved with the skeletonized technique has been proposed as the mode of "protection" of the devascularized sternum.

Against the above background, André Lamy, Hamilton Health Sciences, Hamilton, Ontario, Canada, and colleagues aimed to investigate the association of skeletonized vs pedicled harvesting with internal mammary artery graft patency and clinical outcomes 1 year after CABG surgery.

The researchers conducted the COMPASS clinical trial -- a multicenter, randomized, double-blind, placebo-controlled Cardiovascular Outcomes for People Using Anticoagulation Strategies clinical trial. The trial enrolled 27 395 patients from 602 centers in 33 countries from March 2013 through May 2016. The trial included patients who had undergoing CABG surgery for coronary artery disease with at least 2 grafts implanted and an estimated glomerular filtration rate of at least 30 mL/min.

A total of 1002 of 1448 patients were randomized to the CABG arm of the COMPASS trial and underwent skeletonized (282 [28.1%]) or pedicled (720 [71.9%]) internal mammary artery harvesting. The patients had evaluable angiography results 1 year after surgery.

The primary outcome was graft occlusion 1 year after CABG surgery, as assessed by computed tomography angiography. 

"This post hoc analysis of the COMPASS randomized clinical trial found that harvesting of the internal mammary artery during CABG surgery using a skeletonized technique was associated with a higher rate of graft occlusion and worse clinical outcomes than the traditional pedicled technique," concluded the authors. "Future randomized clinical trials are needed to establish the safety and patency of the skeletonized technique."

Reference:

The study titled, "Skeletonized vs Pedicled Internal Mammary Artery Graft Harvesting in Coronary Artery Bypass Surgery: A Post Hoc Analysis From the COMPASS Trial," is published in the journal JAMA Cardiology.

DOI: https://jamanetwork.com/journals/jamacardiology/article-abstract/2780714