New Device Improves Outcomes of Coronary Bypass Grafting

Venous external support (VEST) may improve longevity and durability of leg vein grafting during coronary artery bypass surgery, as per the new trial. The results were published in Circulation. “Vein grafts have a limited durability—about half of them will be closed 10 years after coronary bypass surgery.

We need to find a solution to improve outcomes of surgery and prevent patients from having complications and repeated procedures,” says Principal Investigator John Puskas, MD, Chair of Cardiovascular Surgery at Mount Sinai Morningside.

Coronary artery bypass surgery, also known as CABG, is the most commonly performed cardiac operation, and improves survival in patients with complex left main and/or multi-vessel coronary artery disease.

VEST is a small device made of fine cobalt-chromium wire mesh that is placed over a pencil-size vein graft. The external support is designed to prevent veins from stretching under higher pressure, thereby leading to better survival of vein grafts and improved patient outcomes.

To study VEST’s efficacy, researchers conducted a randomized patient trial in 17 cardiovascular surgery centers in Canada and the United States between January 2018 and February 2019. They enrolled 224 patients scheduled to undergo CABG with two or more saphenous vein grafts.

Patients were their own controls: for each patient, one vein graft was supported with VEST and the other vein graft or grafts had no external support.

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Investigators used the thickness of the inner cell layer lining the vein graft as the measurement to determine the success of the trial. Researchers placed a catheter inside the vein graft and conducted an intravascular ultrasound 12 months after surgery.

203 of the 224 patients returned for the one-year follow-up angiogram and intravascular ultrasound.

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90 of them did not have intravascular ultrasound completed for both vein grafts, due to narrowed grafts or other technical reasons including catheter issues; for these patients, researchers replaced missing information with substituted values from estimates based on data already collected from other patients in the trial.

Data from these 203 patients showed that VEST did not significantly reduce intimal hyperplasia in vein grafts after coronary bypass surgery, compared to non-VESTed vein grafts.

But when researchers did the same type of analysis on the subset of 113 patients who did complete ultrasounds on both VESTed and non-VESTed grafts, the VESTed grafts had statistically significantly lower amounts of hyperplasia compared to non-VESTed grafts.

“These findings are encouraging despite the fact that the p-value of the primary analysis did not quite reach statistical significance. It may be important to note that among patients with complete intravascular ultrasound data the VEST was associated with statistically reduced intimal hyperplasia,” Dr. Puskas says.

The investigators plan to continue follow-up of these patients for five years after surgery.



Source-Medindia