Surgeon Reports

Quality in Coronary Artery Bypass Surgery

What benefit does SPY imaging deliver to a cardiovascular surgeon during a coronary bypass surgery?
With regards to imaging, if we get to the stage where the patient has decided they do want a bypass operation, the reason we would like to perform imaging of the grafts is to ensure that all the grafts are patent when the patient leaves the operating room. This, of course, is very important because it is the patency of these grafts which ensures a good long term outcome. The single most important component of that operation is to have a patent mammary artery graft to the major blood vessel in the front wall of the heart, the so-called left anterior descending vessel. Why is this important? We know from many studies, very good studies, done at the Cleveland Clinic almost two decades ago now, that if you have a patent internal mammary artery to the front wall of the heart it increases your long term survival. So in the operating room, if the surgeon does nothing else, that is the one graft that they really want to be, not 98% sure in their mind that is okay, but they want to be 100% sure and that’s what this technique enables them to do.

What is the single most important piece of information that SPY can provide intra-operatively?
I think the single most important part of the information from the SPY Novadaq technology is to check that the grafts are patent and particularly the internal mammary artery to the front wall of the heart. In reality it is not only useful for the surgeon to know that - it can be useful for the patient to see images and for the cardiologist who referred the patient for the operation to see that there is documented evidence of graft patency. So, in general, reassurance to everyone involved from the patient to the physicians. However, the real importance of the information is what you get in the operating room because that is the time, if you find there is a problem with your graft, you have the opportunity to fix it.

What risks are the patient exposed to during a CABG procedure in which the surgeon does NOT use SPY?
If you undergo a bypass operation and one or other of the grafts is not patent at the end of the operation and you haven’t checked that because you haven’t used, for instance, the SPY Novadaq system then it means that that patient, in terms of their long term future, is both at increased risk of death over the long term and indeed may still have a poor symptomatic result from the operation. They may still have angina or breathlessness, and they may, almost certainly in fact, require further interventions.

Being a thought leader in cardiac surgery, what advice can you offer to your peers regarding SPY imaging?
In terms of speaking to my colleagues who may be thinking of using the SPY Novadaq camera system for imaging grafts, my advice to them would be the only reason now that a patient is even referred for coronary artery bypass grafting is to get a mammary artery to the left anterior descending coronary artery, because that is the graft that is proven to affect the patient’s long term survival. That’s something that will guarantee additional survival. So if, in the operating room, you do nothing else except check that the patient is leaving your OR (operating room) with a patent mammary graft, you have changed that patient’s long term survival prospects.

Why is it important to use SPY?
Why is it important to do it? Because we know that even in the best hands in the world there is still somewhere (between) a 2% to 5% failure rate of internal mammary artery grafts in the operating room, and often there is no sign of it. The ECG doesn’t change. The blood pressure doesn’t change. Unless you actively check your graft patency you are going to miss this in a small proportion of patients, but since it is such a vital graft for the patient – it is worth checking that it is patent before they leave your operating room.

What is the effect of SPY on the long-term treatment of patients?
The one thing that we do know is that if the mammary artery graft is patent when the patient leaves the operating room, it is very likely to be patent 20 years later. So if you get it right the first time and you’ve checked you got it right, you have made a very important contribution to that patient’s long term outlook. The other thing to point out, of course, is no cardiologist would dream of putting a stent in these same vessels on which you operate without checking their result and we should be doing the same.

- Dr. David P. Taggart, MD, PhD, FRCS

David Taggart is currently Professor of Cardiovascular Surgery at the University of Oxford (2004-) and a Consultant Cardiac Surgeon at the John Radcliffe Hospital (1995-) in Oxford. He qualified from Glasgow University in 1981 and pursued his basic surgical training in Glasgow. In 1989 he was awarded an MD with Honours and he was subsequently appointed the Senior Registrar at the Royal Brompton Hospital under Professor Yacoub and Mr Lincoln (1992-5).
His main interests are coronary revascularization, arterial grafts and off pump surgery. He has authored over 120 peer-reviewed scientific papers and is the co-editor in chief of the Journal of Cardiothoracic Surgery.