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Angioplasty.Org Interview Series: Transradial Approach
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Interview with Tak W. Kwan

In this interview, Angioplasty.Org discusses the transradial approach to catheterization and intervention with Dr. Tak Kwan. For a number of years, Dr. Kwan has worked closely with Dr. John Coppola of St. Vincent's Hospital in New York City. Both Dr. Kwan and Dr.Coppola traveled to India in 2003 to learn the radial technique from Dr. Tejus Patel.

Currently Dr. Kwan is an Associate Clinical Professor of Medicine at the Albert Einstein College of Medicine in New York and is also an NYU School of Medicine Senior Associate. He serves as Director of the Cardiac Catheterization Laboratory and Interventional Cardiology at Beth Israel Medical Center in Manhattan.

The last two radial training courses at St. Vincent's Hospital, co-chaired by Dr. Kwan, have filled to capacity very quickly, bolstering the perception that interest in the radial approach to catheterization and intervention is growing.

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



Tak W. Kwan, MD, FACC, FACP
Tak W. Kwan, MD, FACC, FACP
Beth Israel Medical Center

Q: What is the role of specialized equipment that is designed specifically for the transradial approach, where a catheter is inserted into the circulation via the radial artery in the wrist?
Dr. Kwan: The equipment is very important when we do radial intervention or radial catheterization. From the needle itself -- there's a difference in the needle we use for the femoral access. Also the introducer sheath is very important. For example, Terumo makes a perfect one, called the GlideSheath, so it really helps us go into the radial artery without difficulty.

One of the difficulties we have encountered going into the radial artery is radial artery spasm. This GlideSheath minimizes the friction between the arterial wall and the plastic, so the spasm is decreased. Second thing is that when we do the radial cardiac cath intervention, we encounter a lot of different anatomy and, for example, I like using GlideWire, also by Terumo. We can go around a bend and a curve without major difficulty.

The third piece of equipment that can make the radial approach friendlier to the operator is the catheter itself. Right now many operators are using the femoral Judkins catheter for radial. That catheter is from 1960's and it has a pre-formed curve. And it's okay for skillful people to use it for the radial with not much difficulty. But, for a beginner, there is still a learning curve. So if we can make a perfect catheter from the radial approach, one that can minimize the learning curve, everybody will be happy to use it.

Q: You recently wrote a paper on the Optitorque catheter, which we have published on Angioplasty.Org. It is interesting because in the early days of catheterization, there were two techniques: the Sones technique (brachial approach) and the Judkins technique (femoral approach). The Sones technique allowed the operator to use a single catheter to do both the left and right heart caths, but it was a bit difficult to perform, almost surgical regarding the cut-down and access. Then Judkins developed a set of pre-formed catheters for use in the leg/groin, or femoral, artery. Radial seems more closely related to the Sones technique.
Dr. Kwan: The Judkins technique is for right coronary and left coronary, but using two different catheters. It's pretty friendly to use from the femoral approach, but there's also one catheter we call a multipurpose catheter which you can use to go from the femoral approach to do a left coronary, right coronary and LV-gram. This can be done from the femoral approach, but you would need to learn how to engage the different arteries.

The Optitorque is using the same idea, but using it in a radial approach, so we can engage the left ventricle, the right coronary, and the left coronary using one single catheter. It's similar in idea to the multipurpose. And the advantage is that if we can use one catheter, we have less cost, less contrast, less radiation. This is the bottom line -- and it's friendlier to use, so no one will worry about having to learn a new technique – the radial technique. So a new beginner may be less fearful to do radial artery catheterization.

Q: Besides equipment, what do you do to help minimize the occurrence and radial artery spasm?
Dr. Kwan: When we go through the radial artery, and I usually go through the right radial, the first thing is the introducer sheath. Radial artery spasm -- that's something we still need to be concerned with. It’s much better than before, but we still need to have better medication. We give a cocktail. Every patient we give nitroglycerine, verapamil, to combat radial artery spasm. It still happens and we need a better medication in the future.

Q: What percentage of your patients do you do via the radial approach?
Dr. Kwan: I do almost everyone as a radial, unless I cannot find a pulse -- over 90%.

Q: And what is your complication rate?
Dr. Kwan: My bleeding complication rate is zero! No bleeding complications. No hematoma, no bleeding requiring transfusion, zero! The one complication I have in my practice now is radial artery occlusion, about 1-2%. The reason is multifactor: some patients have a smaller artery, sometimes it’s a prolonged procedure, or repeat trauma such as multiple procedures done through the radial artery. To achieve hemostasis, we have used a big bandage and sometimes the pressure is too long. Dr. Samir Pancholy has taught us a lot about how to use the TR Band, so now we are using less pressure for shorter times.

Q: Normally, when the femoral approach is used, it is impotant to apply significant pressure over time to achieve hemostasis. Is it fair to say that the techniques for achieving hemostasis in the femoral approach are not applicable to the radial?
Dr. Kwan: Yes. In the femoral, stronger is better, but in the radial, softer is better.

Q: Considering the advantages of no bleeding complications, increased comfort, etc., why isn’t the radial approach used more in U.S.?
Dr. Kwan: One of the problems is the steep learning curve. So we need to cut down the learning curve. Terumo is offering training with simulators, and that's really helpful. And have teaching courses, so we can teach tips and tricks. Another thing is a fellowship training program: John Coppola and I are working very hard on that. So fellows go out, sometimes to academic institutions and they train more fellows in the radial approach. So it's not an overnight success, but it will be there in the future.

We're seeing nowadays with the bleeding complications so low, all the major manuscripts and papers coming out, all these trials, all these meta-analyses -- and everybody can believe in that -- it's real data. So this will improve the numbers and it won’t be in single digits in a couple of years: we'll be going to 10, 20% very soon. Also the recent study from Dr. Rao will be very helpful.

Q: Thank you for your time!
Dr. Kwan: My pleasure.

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