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Angioplasty.Org Interview Series: Transradial Approach
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Shigeru Saito, MD

As part of its ongoing interview series on the transradial approach, Angioplasty.Org recently talked with Dr. Shigeru Saito, Director of Cardiology and Catheterization Laboratories, Shonan Kamakura General Hospital, Kamakura, Japan. Dr. Saito is one of the leading supporters and practitioners of transradial coronary intervention (TRI) in the world. As an evangelist for TRI, he has traveled the world to teach and demonstrate the benefits and techniques of this alternative to the femoral approach.

One of Dr. Saito’s primary activities is to develop a strategy of retrograde approach in coronary angioplasty for chronic total occlusion. He serves as President of NPO International TRI Network. He serves on the editorial boards of Catheterization and Cardiovascular Interventions, Journal of Invasive Cardiology and the International Journal of Cardiology. Dr. Saito is widely published in the fields of acute myocardial infarction, cardiomyopathy, coronary angioplasty and the transradial approach.

For more about the transradial approach, visit our Radial Access Center.



Shigeru Saito MD
Dr. Shigeru Saito teaching
during a live demonstration course

Q: How did you first learn about the radial technique for angioplasty?
Dr. Saito: Over the past twenty years, I have travelled a lot to foreign countries to do angioplasty, PTCA, and it was in 1995 that I visited Taiwan to do angioplasty. And there I met Dr. Chiung-Jen Wu from Kaohsiung and he was doing the transradial approach. I was very surprised because I knew the transradial approach, but I supposed that it was possible only for Western people, because their body size is big. So when I saw that it was possible, feasible, even for these Chinese patients, after coming back to Japan, I declared that from then on I would completely switch to the transradial approach.

Q: At that time, when you started, what was the percentage of cases in Japan that were done transradially?
Dr. Saito: Zero! No one. I was the first to do transradial approach in Japan.

Q: Why did you switch to the radial approach? Cardiologists we’ve interviewed often say they did because the radial approach has fewer complications.
Dr. Saito: Why switch? Because it was something new. And I always want to try something new! So that’s the reason. In those days nobody knew that the transradial approach had a lower complication rate. It’s true, but it was not proven in the Japanese patient population. So my strategy was completely switched to the transradial approach and my role was to show if that approach was good or not in the Japanese patient population.

Q: That was a decade ago. What percentage of cases is being done radially in Japan now?
Dr. Saito: I think, among angioplasty procedures, maybe 50%.

Drs. Coppola and Saito in NYC
Drs. Coppola and Saito during
transradial case at
St. Vincent's in NYC

Q: That’s quite a change. In the U.S. it’s only in the single digits, except in specific hospitals where radial is practiced -- in those it’s more like 50%. Can you make any suggestions for physicians who want to learn the transradial approach?
Dr. Saito: I think the most important thing is you have to totally switch to the radial approach. It’s very important. Some physicians want to do transradial approach in a very small number of patients. For example, if the femoral access failed – some physicians want to take the radial approach only for those cases. But it’s not good. In my hospital, we always take the radial approach, so from the beginning young physicians are getting familiar with transradial approach.

Any physician can visit hospitals, like St. Vincent’s, and they can learn. Also right now we have a very good simulator and all young physicians can try it. It’s fast.

Q: In your opinion, what is the learning curve for radial? How many cases before one can be comfortable with it?
Dr. Saito. I think 50 cases. But after we cross that learning curve we can do anything from the radial approach.

Q: For example, do you ever use Rotablators?
Dr. Saito: Yes, and also the Directional Coronary Atherectomy (DCA) device. It needs an 8F guiding catheter, but I published several years ago on the radial artery size in the Japanese patient population. And we found that for Japanese male patients, about 40% can accept 8F in radial.

Q: Is there anything you cannot do from the radial approach? You are one of the experts in opening chronic total occlusions (CTO) – do you use radial in those?
Dr. Saito: For example, today I did the femoral approach in some cases because I could not feel any radial pulse. Also another situation is if the patient has chronic hemodialysis for renal failure. In that case we have to preserve the radial shunt, so in those cases I never touch the radial.

The only problem for CTO angioplasty from the radial approach is that sometimes we need a bilateral injection. For example, if the occlusion is in the LAD, sometimes we need a right coronary injection. That means we need two catheters simultaneously. And from the radial artery approach, because the artery is smaller, we cannot do two catheters simultaneously. But from the groin, because the size of the artery is big, sometimes we can take two punctures from the same side [or one from each approach].

Q: In one of today's cases, you did simultaneous injections, using one from the femoral and one from the radial. Which brings me to a question: have some of your patients experienced both the femoral and radial approaches, and what are their opinions?
Dr. Saito: Of course, the patient’s preference is from the wrist, because the patient can get up immediately and even can go home immediately.

Q: Do you find that patients come to you or to your hospital specifically because you offer transradial?
Dr. Saito: Yes, yes. Of course. Because we are very famous for doing the transradial approach. But that’s a problem, now. The transradial approach is getting very popular in Japan, so I have no advantage anymore (laughs).

Q: I see. So you’ve taught yourself out of a position....
Dr. Saito: Yes!

Q: What do you think needs to happen in the U.S. for transradial to spread?
Dr. Saito: What happened in Japan when we started the transradial approach, in the initial phase, we had a lot of trouble, skepticism from some physicians. They are a little bit older, you know, and they never wanted to start the transradial approach, because they are only familiar with the femoral approach. And I think the same thing will happen in any country -- also in the United States, even in New York City.

So the most important thing is that we have to create some kind of community of radial physicians. It’s very important. The physicians must have some kind of periodical or meeting, small meeting or big, perhaps during the SCAI or something like that. And there has to be a mutual exchange of opinions.

    Dr. Saito with cath lab team
Dr. Saito with catheterization
laboratory team

Q: Why do you feel the radial approach is important in PCI (Percutaneous Coronary Interventions) today, especially when anticoagulant therapies are used extensively?
Dr. Saito: From the femoral groin, the first thing is that the artery size is huge, very big, and near the artery we have a very important nerve. So if we have something like a hematoma or bleeding here, we have a lot of complications from the groin. But from radial, behind the artery there is a bone, and in front of the artery there is skin. So that means no space around the artery from the wrist, so the chance of causing bleeding is very low. Also, along the radial artery there is no nerve.

Q: In the U.S., a lot of physicians use vascular closure devices to help stop bleeding in the femoral artery.
Dr. Saito: Any comparative data shows that the best way from the femoral groin approach is compression, manual compression. And any hemostasis device has a higher incidence of complication.

Q: How do you achieve hemostasis in the radial approach?
Dr. Saito: We have some kind of band. We don’t need anything; just hold the band here and the patient can move and walk immediately.

Q: With the growth of radial access, are you now doing outpatient angioplasty?
Dr. Saito: We call it one-day admission. No overnight.

Shigeru Saito, MD
Shigeru Saito, MD

Q: Thank you Dr. Saito. We look forward to watching you perform cases during Dr. Coppola and Kwan’s upcoming course at St. Vincent’s Hospital in New York.
Dr. Saito: You are welcome.

NOTE: Dr. Saito will be on the guest faculty for an upcoming course on the transradial approach at St. Vincent's Hospital in New York City being held on June 12-13, 2008. The course is fully enrolled, but future courses will be announced in Angioplasty.Org's Radial Access Center.

This interview was conducted in April 2008 by Burt Cohen of Angioplasty.Org.