Thank you. I hope you can see my screen. So, yeah, I will discuss two surgical issues, the use of the radial artery as a conduit for CABG and the role of pump surgery. Let's start with the radial artery. That was a considerable change in the current guideline compared to the previous one. The radial artery received a class one indication to be used to complement the LIMA 2LAD during bypass surgery. So the reason for that are, first of all, related to the patency of the conduit. This is a network meta-analysis that we have performed of all the randomized trials, 13 randomized trials, more than a thousand grafts, that have looked at the patency rate of the different conduits using bypass surgery. And you see that the comparator is the traditional saphenous vein. And the only conduit, the only two conduits that at five years follow up at a significantly better patency rate compared to the saphenous vein, the traditional arvested saphenous vein, where the radial artery and the so-called no-touch saphenous vein. The other arterial conduits that are generally used in coronary surgery, the gastro-pupillary artery, and most importantly, the right internal thoracic artery, for those other conduits, there was not enough evidence to prove better patency rate. And so if patency is the mechanism that drives the clinical benefit of CABG, this is a pretty compelling reason to give the radial artery plus one indication. In terms of randomized data, looking at the clinical outcome, there has not been a single randomized trial testing the radial artery hypothesis. There is, however, this patient level meta-analysis that pulled the data from five smaller angiographic trials that were comparing the radial artery with the saphenous vein around a thousand patients. At five years follow up, we found that the use of the radial artery as compared to the use of the saphenous vein for the second most important target was associated with a statistically significant reduction in the composite outcome of major cardiac events, DECIMI, and repeat revascularization. That was accompanied and probably explained by a statistically significant reduction in the risk of graft failure for the radial artery. At five years, we did not find a statistically significant difference in survival. There was a clear and large and statistically significant difference in terms of repeat revascularization. And there was also a nominal statistical significant difference for MI in favor of the radial artery. We then extended the follow up of those patients to 10 years, and that was relatively fast because they were relatively older trials. In the 10 years follow up, we found we not only confirmed the difference in the extended composite outcome of DECIMI and repeat revascularization, but we also found a statistically significant reduction in the risk of a composite outcome that included only DECIMI, so only clinically important events. So this is the basis, the rationale for the class one recommendation on the radial artery in our guideline. However, we also specified the best practice for the use of this conduit. It is not a conduit that can necessarily be used in every single patient. We specified that clearly the completeness of the palmar arch, which is not important for the user, at least as much as I know, for the use of the radial artery for transradial catheterization, is important when the artery must be used for bypass surgery. We also specified that the radial artery graft should be used to target the vessel with subocclusive stenosis because there is evidence that the severity of target vessel stenosis and the absence of the limited amount of chronic competitive flow is critical for long-term patency of the radial artery. We also specified the radial artery should not be used after transradial catheterization. There is evidence that the endothelial damage due to transradial catheterization lead to significantly worse patency rate, and we also thought, even though there is no evidence on that, the patient with chronic kidney disease should not receive the radial artery because in those patients, the radial artery is generally used as a source of flow for the AV fistula. We also pointed out that the use of oral cancer channel blocker, at least for the first postoperative year, seemed reasonable. There is data, even though it's observational data, post-hoc analysis of our Nijmeg paper, that suggests that the use of the radial artery in patients, the use of calcium channel blocker in patients who receive the radial artery is associated with better patency rate and improved clinical outcome. And then we also specified that to avoid bilateral radial artery procedure, either surgical or percutaneous, so to save one of the other arteries for eventual future intervention. So this is it for the radial artery. I will jump quickly to off-pump CABG. There is no recent data on off-pump CABG. The technique was introduced in the late 90s with the idea of avoiding the consequence of the use of cardiopulmonary bypass. There had been a number of randomized trials. The problem with off-pump CABG is that the avoidance of cardiopulmonary bypass and the reduction of systemic inflammation come at the price of higher technical complexity. And there have been reports, numerous reports, of lower patency rate and less complete revascularization using off-pump surgery. This is a meta-analysis of the all the trial that compared on versus off-pump surgery with a minimum follow-up of five years showing a significantly better mortality using on versus off-pump surgery. So that was clearly one of the reasons why off-pump surgery is not routinely used almost anywhere in the US, Canada, and Europe, except for selected patients. The reason why it can be used in selected patients this is an example. This is the largest trial comparing on and off-pump surgery, the coronary trial, and that 30 days follow-up you see that they found a lower rate of repeat revascularization in the off-pump group, but they also found a lower rate of respiratory failure and renal failure, even though for renal failure that was mostly even from less severe form of renal failure. But the avoidance of the systemic inflammatory reaction of total pulmonary bypass may be beneficial in terms of respiratory function, and this may be important in a specific subset of patients. We have also shown that there is an association between the surgeon comfort and the experience with the technique and the outcome. This is a meta-analysis of the on and off-pump versus off-pump trial where we stratified trial based on the crossover rate. The crossover from on-pump of off-pump is generally considered a good marker of the surgeon comfort with the experience, and we found out that for the higher the crossover rate, so the less the experience and comfort of the surgeon with the off-pump technique, and the worse the result for the off-pump technique. And even this is based on observational data, but we will look at the comparison of off versus off-pump on-pump surgery based on off-pump volume, and for site, for hospital that were performing a low number of off-pump cases, on-pump surgery was better. The opposite was seen for hospitals that were performing off-pump surgery on a more regular basis, and this is a large observational study in New Jersey showing better results, better long-term results with on-pump surgery, but not the number of off-pump operations per surgeon, 142. A similar exercise from the UK, much higher number of surgery per surgeon and totally different results. So experience probably matters when as far as off-pump surgery is concerned. The reality is that currently between 15 and 20 percent of the operation in the United States, this is overall in the STS database, this is in New York State, but probably around 20 percent of the cases are performed off-pump. A very important indication, however, for off-pump surgery is the reduction of neurological risk. With some technical modification, off-pump surgery allows what is defined anaortic surgery, so CABG surgery without manipulation of the aorta, and this has been shown in observational studies to significantly reduce, as you can see here, the incidence of intraoperative stroke, and this is how grafts are arranged to avoid any manipulation of the ascending aorta. So it is used in a minority of operations. Surgeon experience is important. It may be advantageous in selected high-risk population. This is what we essentially say in the guideline. We provide a class 2a recommendation to avoid aortic manipulation in a patient at high risk of stroke, and the less strong recommendation class 2b to improve pulmonary outcome when performed by experienced surgeon, and I think this is it.

radial artery

coronary artery bypass grafting

off-pump CABG surgery

saphenous vein

patient-level meta-analysis