Transradial Access: Learning with a New Virtual Reality Tool
- Posted on: 6/19/08
- 0 Comments
- 3476 reads
The most important thing has been the consistent reports of the positive benefits for patients undergoing transradial procedures. Interventional tools are getting smaller, and virtually all of the procedures interventionalists perform can now be done transradially. Previously the need for smaller catheters was a limitation to the technique; the radial artery is obviously smaller than the femoral artery. But now there really are no technical disadvantages when you go to transradial access.
Another important development is that the honeymoon period for femoral closure devices is now over. Physicians have realized that there are still significant groin complications if you use a closure device after an interventional procedure. In fact, there are new groin complications, such as infections, that we didn't see before the use of closure devices.
There has also been increasing interest from university-based physicians. The physicians who teach interventions were previously not comfortable with transradial access being incorporated into the program at their hospital. This was a significant impediment to its adoption in the U.S., since there was no training in fellowship. Yet now we're seeing more university-based interventionalists using this technique.
Europeans have been proactive in doing outpatient stenting procedures. Even though at present it is not reimbursed in the United States, I think it will be just a short period of time before outpatient stenting procedures are performed here. Right now, U.S. hospitals are not paid by insurance companies if procedures are done as an outpatient. I would expect that within the next 12-18 months this will change. Several studies have now been published demonstrating that it is safe to send selected patients home the same day after stenting.
The lack of payment by insurance companies has been one obstacle to outpatient stenting in the United States.
Yes, I think that in general, American physicians tend to be a little more conservative than Europeans. We have legal aspects to worry about, the result of which is that American physicians are much more cautious. Really, it's just been in the last several years that enough studies have been published to prove that outpatient stenting is indeed safe.
What have been some of the obstacles to mainstream adoption of the transradial procedure?
You really can’t say mainstream, because it’s really only an issue in the United States. Worldwide, transradial access has been adopted in huge numbers. In the Far East, for example, probably 30-35% of all interventions are done transradially, and in France, over 50% of all interventions are done transradially. The mainstream has accepted transradial access; it’s the U.S. which has been very slow in adopting it. This is because of the factors we talked about: the hope of femoral closure devices and that most physicians these days are not trained in arm techniques. The standard of training in the United States is the femoral technique. There’s also not been a lot of support from national professional organizations. Plus, there is still an awful lot of what I would call low-volume operators in the United States physicians who do less than a 100 interventions per year. I think in these situations, physicians are very reluctant to take on a new technique, particularly when they haven’t had any training.
We had a 5-hour transradial session with edited live cases at TCT this year and really had an excellent attendance. This reflects the increasing interest in the technique in the U.S.
How does the transradial learning curve compare to that of learning femoral access?
Of course, there is a learning curve for both. With the transradial approach, it’s a little steeper, because many physicians are not comfortable with doing procedures from the arm. The radial artery is a smaller vessel, and technically it’s a little more challenging. The positive aspect is that the patients overwhelmingly prefer to have procedures done from the arm as opposed to the leg. In centers where they do transradial, I think that patient and nurse enthusiasm perpetuates the technique.
Can you discuss a few of the recent meetings focused solely on transradial access?
Our hospital (Wake Heart Center, Raleigh, North Carolina) hosted a transradial course in April 2006. Over two days, approximately 20 live cases illustrating a variety of technical challenges were interspersed with lectures from several international experts. We also have daily courses for individual physicians throughout the year.
The TRIP 2006 (TransRadial Interventional Program) meeting at Mercy Hospital in Scranton, Pennsylvania took place this past July. It was a meeting in which the transradial approach was discussed in detail, and live cases were done. A solid faculty was present, a lot of ground was covered, and it was quite comprehensive for a one-day meeting.
The 14 years of TRI Annual Live Demonstration Course was held in Amsterdam on October 13-14. The OLVG interventional group, headed by Dr. Kiemeneij, performed the first coronary angioplasty via the radial artery in 1992, and continues to be leading advocates of the technique. This course always discusses the latest developments with the technique.
How did the transradial access simulator come about?
The simulator was developed by Mentice, in cooperation with Terumo Interventional Systems and with Dr. Shigaru Saito (Shonan Hospital, Kamakura, Japan), Dr. Gioria Weisz (Columbia University, New York) and Dr. Yves Louvard of the Institut Cardiovasculaire Paris-Sud (Massy, France) as clinical advisors. It is going to break new ground for us in terms of training. I think this simulator is one of the most amazing teaching tools I’ve ever seen. The variety of cases incorporated in the simulator includes many of the challenges physicians face in learning the procedure. Physicians can do transradial procedures on the simulator and face situations that would arise in daily practice. They will become comfortable handling not only catheter selection but problems that may arise during day-to-day technique. This simulator is a major, major step for transradial access in the United States.
How is the simulator set up?
The module takes the place of the patient. Physicians actually perform a transradial procedure from access to completion.
How long has it been up and running?
Terumo Interventional Systems unveiled it at the October 2006 TCT meeting for the first time. My partner, Dr. Lee Jobe, was involved in several training sessions at the meeting. There are also other high-volume transradial operators in the United States and in Europe who served as proctors.
What are some of the issues in terms of gaining access that the simulator can test?
Again, it’s the alien territory for the femoral guys. It’s a smaller artery, we use different tools, and the routes that are used to the heart are different. These are not necessarily problems, but there are challenges that come with dealing with the upper extremity as opposed to the leg. The route to the ascending aorta is new. Catheters used may be different. Thus, learning to gain access to the coronaries is a new technique in many ways. All of these issues are addressed by the simulator.
Could you discuss some of the procedural complications that the simulator might show? Occlusions, spasms is perforation an issue?
Perforation is not an issue with good technique. There are a large number of small side branches that can entrap guidewires and perforations can occur without careful technique. I haven’t seen a specific case on the simulator, but it certainly will be addressed. Radial artery spasm can be a problem if not dealt with properly.
You mentioned that some of the tools involved in gaining transradial access are different than with femoral access.
The primary difference is size. We use a 20 gauge needle and 0.025 hydrophilic guidewire for radial access. There are actual commercial products now that are designed specifically to gain access in the radial artery and help the ease of access. Terumo Interventional Systems makes a radial access kit.
What about post-procedure hemostasis?
That’s the beauty of the transradial access procedure the radial artery is isolated and it’s not surrounded by nerves or soft tissue. Selective compression is very easy. Bleeding complications are virtually eliminated. Catheters are removed immediately after the procedure, regardless of the level of anticoagulation. There are a variety of homeostasis devices available commercially, and one new device that has major advantages will be available next year.
How long are patients typically on bed rest after a procedure?
Most patients can ambulate immediately. I recently visited Dr. Ferdinand Kiemeneij’s laboratory in Amsterdam. He has developed a radial lounge, much like a business class lounge in the airport. Patients are encouraged not to stay in bed and there were post-procedure patients walking around in this lounge. Several were playing chess at a table, using computers, or sitting watching TV. In fact, the seven or eight procedures that morning were done with the patients wearing their street clothes. The patients walked out of the cath lab into the lounge. It really illustrated the immediate mobility that these patients can have. Nobody’s complaining of back pain and there are no indwelling bladder catheters. Early ambulation significantly improves patient comfort and outlook.
So this method of access might be particularly good for obese patients?
Well, with obese patients the risk of femoral complications is certainly higher. But I think that rather than trying to select certain patient subgroups, it’s better to consider transradial access as beneficial for everyone. There are some subgroups where the benefit is greater, but the general population of patients undergoing catheterization or intervention does better with transradial access, both physically and psychologically, than with femoral access.
How long have you been involved in doing transradial procedures?
We started in 1994. At that time, we were using coumadin for anticoagulation after stent-deployment. The groin complications in that era were horrendous, and this was the stimulus for us to change arterial access sites. The subsequent benefit that we saw for patients has accentuated our commitment to the transradial approach.
The simulator was presented to physicians for the first time at TCT. Will it also be available at any upcoming meetings?
Terumo Interventional Systems is sponsoring the simulator, and I think they have plans to be at just about all the meetings.
Are the training sessions for physicians only, or would nurses and technologists also benefit?
It’s primarily geared towards physicians, but certainly nurses and techs that have not been exposed to transradial technique would be interested in seeing it.
Dr. Mann can be contacted at Wake Heart and Vascular Associates
Raleigh, North Carolina, Tel. (919) 212-3875.