Macquarie University Hospital surgeon Professor Michael Vallely and his team have completed a network meta-analysis of the latest evidence for off-pump heart surgery across the world. The research shows that a ‘no touch’ or ‘anaortic’ approach has a significant impact on reducing stroke.

Coronary Artery Bypass Graft (CABG) is the standard treatment for three-vessel heart disease. But CABG is associated with a higher risk of stroke – either as a result of a patient being on the cardiopulmonary bypass (CPB) pump or as a result of manipulation of the aorta by aortic cross-clamping.

While it was previously thought the CPB pump was the main cause of stroke – with many taking up off-pump surgery as a result – Professor Vallely and a group of surgeons turned their attention to eliminating manipulation of the aorta, developing a ‘no touch’ approach to CABG – anaortic Off-Pump CABG (an OPCABG).

“Ageing and co-morbidities bring increased atheromatous (cholesterol plaque) disease in the aorta,” explained Professor Vallely. “Manipulating the aorta means that bits of atheroma can break off and go into the brain, causing a stroke.

“Anaortic OPCAB relies on taking blood flow from the internal mammary arteries that run behind the sternum, rather than from the aorta. Because the aorta is not manipulated and inflow for the bypass grafts is taken from vessels other than the aorta, the chance of an embolic stroke occurring during the procedure is virtually eliminated.”

Professor Vallely’s team has now examined the clinical evidence available. Their network meta-analysis, ‘Coronary Artery Bypass Grafting with and without manipulation of the ascending aorta’, was published in the February issue of the Journal of the American College of Cardiology.

The meta-analysis looks at four different ways of doing coronary artery bypass surgery: from completely avoiding manipulation of aorta, to minimal manipulation, to a partial clamp manipulation, to a fully arrested heart using the heart–lung machine and aortic cross-clamp.

“We looked at studies that took stroke as the major end point within the 30-days post-operative period. The studies included a total of 37,720 patients across 13 major studies.

“Patients with minimal manipulation who had greater risk of stroke before the procedure and a larger incidence of pre-operative neuro-cognitive problems showed the best outcomes and a drastic reduction in stroke post-operatively.

“Overall, an OPCABG was the most effective treatment for decreasing the risk of post-operative stroke, reducing incidence by 78 per cent when compared to CABG.”

These patients also had better outcomes in terms of mortality, renal failure, bleeding complications, atrial fibrilation and length of intensive care stay.


Macquarie University Hospital cardiothoracic surgeon Professor Michael Vallely is one of the pioneers of the ‘no touch’ approach to heart by-pass surgery – introducing it to Macquarie University Hospital in 2012.

With fellow heart surgeon Professor Michael Wilson, the pair have done more than 1000 cases using the technique. They are amongst the most experienced surgeons in the World using this technique.


Given the many approaches to heart surgery these days, patients can be unsure about the best way to proceed. How do you know and where do you go to check that you’re getting the right procedure?

At Macquarie University Hospital, we build those ‘checks and balances’ approach into the way we work with patients. We do this by taking a team approach to heart care, and especially to any of our patients requiring interventional cardiology procedures.

Our team includes surgeons discussing all appropriate approaches and collectively deciding on the best option alongside you, the patient.

This way, patients who come to Macquarie University Hospital for their cardiology services get not only a team of the best to treat them, but an ‘unbiased’ view of their condition and the optimal solution.

If you don’t have a team to review you, then make sure you ask your doctor why you are getting the approach being recommended and how many times they have done the procedure. If you’re in any doubt, get a second opinion.