COMMENTARY

Radial Access: Get Onboard or Get Left Behind

Seth Bilazarian, MD; Sunil V. Rao, MD

Disclosures

January 15, 2015

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Converting Holdouts to Transradial Access

Seth Bilazarian, MD: This is Seth Bilazarian from theheart.org on Medscape, at the Transcatheter Cardiovascular Therapeutics (TCT) 2014 meeting in Washington, DC. I am here with Dr Sunil Rao, from Duke University and section chief at the Durham Veterans Affairs Medical Center.

Dr Rao is well known nationwide around and the world as a leader in educating physicians on the radial approach, and he has published extensively on the subject. He is on the cover of Cardiology Today's Intervention . He was featured in an interview with Michael Gibson from clinicaltrialresults.org at this meeting.

I am going to take a different approach and ask Dr Rao, an international leader and an expert, how I can integrate more new techniques and more good strategies for my patients in the catheterization lab.

You have reported that we are up to about 20% in adoption of the radial approach in the United States, so there is a 4 out of 5 chance that an American patient will not receive a radial approach. What is the most convincing argument for the uninitiated or the frankly resistant?

Sunil V. Rao, MD: You can take two approaches. You can be blunt and say, "This is the way the world is headed, and you either get on board or you get left behind." But there is a more pragmatic argument. You are either a believer in the data, or you are not. The data in total—and we can argue about the subtleties of the data—really do demonstrate that even with contemporary femoral access techniques, radial access reduces access site complications. That is the most common complication after a percutaneous coronary intervention (PCI).

We have seen a remarkable evolution in PCI. Most patients do very well. The things that they complain about, and what we see, are vascular complications. Those can be eliminated with radial access.

Finally, there is a very strong financial argument to be made. The value proposition in PCI is around efficient care models and how you can increase cath lab throughput and get patients out of the hospital more rapidly. The data very strongly show that radial access is part of that strategy.

Formula for Success: A Fully Committed Cath Lab

Dr Bilazarian: In your efforts as one of the co-directors of the Society for Cardiovascular Angiography and Intervention's Transradial Intervention Program (SCAI TRIP), you are going around the country doing regional programs to bring people education and expertise in radial use and adoption. I practice in two tertiary care hospitals and two community hospitals. Three of the four are radial-first labs, but in the one that isn't, it is very difficult even for me as a relatively experienced operator to do radial. Do you find that to be an impediment—that if the lab is fully committed from beginning to end vs not fully committed, it makes a difference?

Dr Rao: That's exactly the point. Radial programs are programs. If the operator buys into the program, that's only half of the success formula. You have to get the staff on board. You have to educate the nurses. The radial approach is not rocket science, but it is a science and people have to be educated on the subtleties.

I'll give you an example. When we started our radial program, we forgot to change the postprocedure order set. So when I went to the recovery area, all the patients were on bed rest. It's because we hadn't taken the time to educate the recovery nurses. There are changes in the entire patient experience. Not to sound too administrative, but there are these touchpoints, and every stakeholder has to be educated on what has changed.

Dr Bilazarian: That optimizes results and experience for patients.

Dr Rao: Exactly.

Preprocedure Circulation Testing

Dr Bilazarian: Either you are persuaded by that, or you are not.

For the 20% of proceduralists who are doing this, let's talk about state of the art. Let's begin with preprocedural state of the art. Should I be checking radial palmar arch continuity? Should I do nothing? Should I do just an Allen test? Should I do a Barbeau evaluation with plethysmography? Should I do ultrasonography?

Dr Rao: This is an area that is rapidly changing. We put out our best practices statement from the SCAI radial working group,[1] and we couldn't make a recommendation about preprocedural testing of dual circulation to the hand. We said that this is an area that needs more data. Now, we have more data.

Marco Valgimigli's group recently published a terrific study[2] that would probably be very difficult to do in the United States. In Italy, they took patients with Barbeau tests across the spectrum, including those with a type D response, in whom we have traditionally avoided doing the radial approach. They did a radial approach in them anyway, and they measured outcomes at 30 days, 6 months, and 1 year.

They found that there were no incidences of hand ischemia. There were no changes across the spectrum of Allen test or Barbeau test results in terms of overall hand grip strength or neurovascular function. What was most interesting was that among the patients who had type D when they were tested at a year, a significant proportion of them became type A. That tells us is that there is a tremendous amount of recruitable circulation in the hand.

I encourage people to read that article, but more important, I encourage them to read the editorial by Olivia Bertrand[3] and colleagues, because they say that we should no longer be using these preprocedural tests to deny a proportion of patients the radial approach. The most interesting thing about that editorial is that the second author is a malpractice attorney. In the United States, where we are worried about medicolegal issues, we now have very strong evidence that we don't need to do these preprocedural tests. If there is a palpable pulse, you should go radial.

Ultrasonography is a terrific way of maximizing your radial artery access success. The RAUST trial[4]—and it's hard to show a difference in these kinds of things— showed that first-pass success rates were higher.

Sanjay Chugh's group in India has published data[5] on preprocedural ultrasonography, not only of both the radial and ulnar arteries in both arms but also the antecubital fossa in both arms. Before he gets to the lab, he knows exactly whether a patient has a loop in one side and which is the bigger artery. Those kinds of subtle things can dramatically increase procedure success.

Cannulating the Artery

Dr Bilazarian: Let's move on to the procedure. The patient is in the room, and you either did preprocedure testing or you are just going for the best pulse. Which technique is best? Should I use ultrasonography to cannulate the vessel? How about needles and angiocatheters?

Dr Rao: From an academic point of view, ultrasonography makes a lot of sense. It does require some expertise, and a little bit of capital to get the machine. All things being equal, it's a terrific strategy. Practically, I'm not sure that a lot of people are doing it.

With respect to which technique you should use—the so-called counter-puncture or back-wall technique, where you go through the artery, vs just using an anterior wall puncture—there is a study. Sam Pancholy and colleagues[6] published a study recently showing that the counter-puncture technique has a higher success rate with no difference in complications.

My approach is to do whatever works. Ultimately, you want to get into the radial artery. Some people are more comfortable with the needle. I'm more comfortable with the through-and-through. Just do whatever works.

Dr Bilazarian: How about right or left for novice and intermediate operators?

Dr Rao: That is a great question, and we have some data now. Two studies separated by space and time—one from the Italian group,[7] which is a randomized trial, and one from Chris Pyne and colleagues[8] at Lahey Clinic—show that the patient groups that benefit from a left radial approach (in other words, faster procedure times) are not only those who have undergone coronary artery bypass graft (CABG), but also patients who are over the age of 70 years and patients who are 5'5" or shorter. It's interesting because these two studies found the same height cut-off. The Italian study is in centimeters, but when you convert it, it's about 5'5". That is probably because there is a lot less subclavian tortuosity on the left.

We tend to do our patients with ST-segment elevation myocardial infarction (STEMI) from the left. The data suggest that it is a faster procedure from the left radial artery.

Selecting a Catheter

Dr Bilazarian: So now we are in. We have access, and we are in the central circulation. Which catheters are generally favored for novice operators? I'm a Judkins operator. That's the way I learned, but do you think that it's wise for a physician like me to consider using the radially designed catheters (eg, Jacky, Tiger, Ikari)? I'm not familiar with these. Tell me what operators like me should know.

Dr Rao: This is just like the access: Do what works. I'm a Judkins guy myself. I've used the universal curves for a long time. In my hands, I found that I was able to get both arteries on the first try approximately 90% of the time, but 10% of the time I would spin the catheter around. I decided to go with what I was familiar with.

I have a colleague who is a die-hard universal catheter person. He used one catheter, even if it was a CABG case.

At the end of the day, it's good to be familiar with those curves. You can look at a case and say, "I can't reach this with this catheter. Maybe a Tiger catheter would reach it." So it's important to become familiar with them, but for routine practice, just go with what you are familiar with because at the end of the day, it's about faster procedures and patient comfort.

The Anticoagulation Question

Dr Bilazarian: We are in the central circulation, and we want to anticoagulate because there is good evidence that it prevents radial artery occlusion. How much heparin should be given? Do you give it as soon as you are in the central circulation?

Dr Rao: You have to give some heparin, but we don't know when. We tend to give it after we are over the arch, in case we need to bail out to the femoral approach. Some of that also is just what we got used to doing.

The evidence-based dose is 5000 U. That is the dose that's been used in all the studies. Having said that, obviously for acute coronary syndrome and other conditions, we prefer weight-adjusted heparin. Our approach is 50 U/kg up to 5000 U for the diagnostic catheterization.

Of importance, even if you're doing a diagnostic catheterization on someone who has a therapeutic international normalized ratio (INR), generally we avoid elective PCI. We will do a diagnostic case.

You still have to give some antithrombin therapy. A couple of studies that show that with no antithrombin therapy, even with therapeutic INRs, the radial artery occlusion rate is on the order of 30%. That's an area where we need a lot more information. We tend to give half the dose in that case, but nobody knows the right dose.

Dr Bilazarian: Let's continue. If this proceeds to an ad hoc PCI or a STEMI, you are checking the activated clotting time (ACT) after going around the arch, and the ACT is subtherapeutic. Do you give heparin or bivalirudin?

Dr Rao: This feeds into a larger debate, which is, should we go with bivalirudin or heparin? That's an important question to consider. The access site may play into that. If you look at the HEAT-PPCI trial,[9] with 80% radial approach, it is hard to show a difference in bleeding between those two agents.

In our practice, we are split down the middle. Some of our operators will continue to switch to bivalirudin regardless of the ACT, and many operators will use heparin because that is what they started with. We are going to get a lot more information about this particular topic in the next few years with the SAFARI, EASY-B2B, and MATRIX trials.

Hemostasis: Pressure or Time?

Dr Bilazarian: Now we are at the end of the case, and sheaths and catheters are removed. We use a compressive band. What's the best technique? A variety of techniques have been talked about.

In our lab, we use what I would call "minimum pressure hemostasis" rather than what some people promote as patent hemostasis. To me, patent hemostasis means you actually take the effort to occlude the ulnar and show that there is blood flow with a plethysmography evaluation. However, most people just call minimum pressure hemostasis "patent hemostasis."

Do we need to do patent hemostasis? What are your thoughts on that?

Dr Rao: When we first saw the results from the PROPHET trial,[10] which was one of the landmark studies in the radial approach, they used what they called "patent hemostasis" in the protocol, but they really weren't checking for antegrade flow. That was a huge leap (to call it patent hemostasis). The way we all learned to do this is was to apply enough pressure to achieve hemostasis. You release the pressure, and if you see some bleeding, you increase the pressure again.

But we have learned that there is cyclical flow in the artery. Even a patient who leaves the cath lab procedure room with antegrade flow in the radial artery can, 15 minutes later, not have antegrade flow. In very sophisticated labs, the recovery area nurses will continue to check for antegrade flow every 15 minutes and monitor the pressure that way.

The reality is that it is difficult to implement that. All of a sudden, you have taken a procedure that is in theory easier in terms of recovery and made it a little bit more complicated.

You are right. We are probably not all practicing true patent hemostasis. It probably is minimal pressure hemostasis, but I'm not sure that the difference is too important, because the overall radial artery occlusion rates now are extremely low. It may be difficult to show a difference between those two strategies to begin with.

Dr Bilazarian: Is the value of minimal pressure hemostasis because there is less pressure in the radial compression band, and therefore there is less time because you are taking another 2 mL every 15 minutes? Is it less time rather than less pressure?

Dr Rao: Yes; you hit it right on the head. There are two issues here. There is pressure, and there is time—not to refer to The Shawshank Redemption, but it really is pressure and time.

Some labs believe that it doesn't matter how much pressure you put on it, as long as you take the hemostatic device off quickly. Pancholy and Patel[11] have done a very nice study that suggests that maybe it is a little bit more the pressure rather than the time, but they are probably interacting. It's the fact that you have a little bit of pressure, but you are getting the pressure off very rapidly.

Dr Bilazarian: At the community hospital where I am the director of the cath lab, we looked, for a year, at radial artery occlusions on the next day in patients who were still in the hospital, and we didn't find any radial artery occlusions. I don't think that is the result of anything in particular; we are just doing contemporary things. Is that where we are with radial artery occlusions—they just don't happen very frequently?

Dr Rao: Yes. We did the same thing. We took a 6-month period, and we checked for postprocedure occlusion with ultrasonography, which is a good way of checking. In the patients who came back at 30 days, we checked them as well. Our rate was 0.8%. It was very hard to show that anyone had radial artery occlusion. We know who some of those patients are—elderly, diabetic, small radial arteries—but nowadays, it's very hard to see radial artery occlusion.

Are We Moving to the Ulnar Artery?

Dr Bilazarian: Let me just finish up with a couple of quick questions, because as a leader, you know about future directions. Are we moving toward comfort with the ulnar approach as an option, once we are at the wrist? If we fail to wire the radial, will we just go to the ulnar? Or if we put a sheath in but can't make a radial loop, go to the ulnar? What are your thoughts on that?

Dr Rao: We have done some ulnar cases. The ulnar artery is right next to the ulnar nerve. It's situated a little bit more deeply. A couple of randomized trials[12] were stopped early because there was a higher incidence of forearm hematomas with the ulnar approach. Remember, the ulnar artery is a continuation of the brachial artery, so you almost never see anomalies in it. However, that is a very active area.

When you mention it to people who are just starting to use the radial approach, they think it's a crazy idea. Why would I use the ulnar? In the next few years, we will probably see more information on the ulnar approach, maybe a little bit more movement toward this approach. But I also think that we are going to start seeing the use of radial approach for applications that we hadn't considered.

For example, there was a very nice abstract presentation at the AIM RADIAL meeting using the radial approach to close a ventricular septal defect. The whole world is moving toward minimal invasiveness, and we are going to start using the radial approach for much more than just coronary angiography and PCI.

Dr Bilazarian: The interventionalist Jordan Safirstein tweeted from the TCT meeting that the femoral approach is for transcatheter aortic valve replacement (TAVR). Maybe we will do TAVR in the future from the radial.

Dr Rao: I'm looking forward to that.

Sheathless Guides and Wringing Hands

Dr Bilazarian: Let me ask another question that's on the horizon: Where are we with sheathless guides?

Dr Rao: Sheathless guides that are made by a specific company are available now. They are US Food and Drug Administration (FDA)-approved. They have had a very slow rollout. The company has a small footprint in the United States.

The FDA is requiring that every operator who wants these sheathless guides do five proctored cases before they can use them on their own. It's a little overly conservative, perhaps, but we have done cases with the sheathless guides. They work fine.

They come in 7.5 French, which is nice, but most operators can do almost everything with a 6-French guide. It's just hard for me to remember the last time I had to upsize to a 7.5, but it's nice to know that the option is available.

Dr Bilazarian: Assuming that your success continues—you and Sam Pancholy and the society continue to do a good job in increasing the adoption of radial approach—and that our fellows become proficient, are we going to regret in the future that we have a group of young interventionalists who can't do a femoral approach? What are your thoughts on that?

Dr Rao: I love this topic; this is what I call the handwringing from die-hard femoral operators. A very nice paper was published by Steve Bradley and his colleagues[13] in Circulation: Cardiovascular Quality and Outcomes with the data he presented at the Quality of Care and Outcomes Research (QCOR) meeting, looking at centers that have high adoption of the radial approach and the femoral complications. The same analysis has been done in the United Kingdom. It turns out that the safest place to have a femoral approach done is at a high-volume radial center.

Dr Bilazarian: What a tour de force with Dr Sunil Rao on the state of the art of radial. I have been wanting to connect with him and ask questions, and now I am able to share it with others. Thank you for joining us here for this update of the radial artery catheterization approach with Dr Sunil Rao.

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