What are the Limiting Factors to Greater Use of Transradial Access in the United States?

Transradial access for cardiac catheterization has gained a firm foothold in other parts of the world, but the United States still seems resistant to adopt the procedure as a “first choice” of access.

Is it lack of interest, training, economics, or the perpetuation of urban myth that limits the use of the transradial approach? It appears that an international manufacturer is committed to the training and education for physicians interested in pursuing transradial training.

Cardiac catheterization has it roots and its infancy in access from the arm, specifically the brachial artery by Werner Forssmann. Later, Mason Sones perfected the technique when he accidentally cannulated the right coronary artery while attempting to enter the left ventricle. Thus was born selective coronary angiography from the brachial artery. It wasn’t until approximately 10 years later that Melvin Judkins, a radiologist, developed the transfemoral approach, utilizing specially designed catheter curves that he had developed, a practice that today is still dominate in the majority of cath labs around the world.

There is no denying that the contribution Dr. Judkins provided has impacted millions of procedures all over the world. His development of the Judkin’s catheter curves enables, in the majority of cases, rapid and successful selective engagement of the coronary arteries and; therefore, allows mastery by interventional cardiology fellows prior to the end of their training. So, did vascular access from the arm go the way of the dodo bird? Quite the contrary, it is like the phoenix and has enjoyed a rebirth in many parts of the world, more specifically via the radial artery.

For the past ten years or so transradial access has gained popularity around the world. Japan, France, Italy, the UK, the Netherlands, Scandinavia and Canada have been leading the charge to establish the radial artery as a viable and preferred vascular access site for diagnostic and interventional procedures. Physicians such as Saito from Japan; Louvard, Hamon and Fajadet from France; Kiemeniej from the Netherlands; and Barbeau from Canada have continued to champion the transradial procedure as a viable and preferred method for vascular access, devoid of many of the complications typically associated with femoral access.

In the U.S., there also exists champions of the transradial procedure, but in a country that does over 3 million diagnostic and interventional cardiac catheterizations annually, these numbers have little impact. However, there is a trend developing. Long-time advocates of transradial, such as Tift Mann and Lee Jobe at Wake Heart, Raleigh, NC; John Coppola at St. Vincent’s, New York; Ron Caputo at St. Joseph’s, Syracuse; and Howard Cohen and Kirk Garrett at Lenox Hills, New York have continued to advocate the procedure as providing fewer vascular complications, earning patient preferrence, eliminating bleeding complications associated with thrombolytics, differentiating physician practices, and being more economical than traditional femoral access. When asked why we don’t see the radial artery utilized more as a primary access, the reasons cited by the majority of these physicians are lack of training, steeper learning curve and a general negative perception towards rarely reported radial artery complications.

Several years ago, Terumo, an international manufacturer of cardiology and radiology products utilized in diagnostic and interventional procedures, undertook a project to develop a state-of-the-art radial simulator. This simulator, developed under consultation with Dr. Yves Louvard in France, made possible the ability to simulate the radial access from needle insertion through to completion of a PCI. The learner is thus able to practice the radial stick, insertion of the sheath and the subsequent manipulation of wires and catheters through the radial, brachial and subclavian vasculature and into the ascending aorta with subsequent selective coronary engagement. The operator is able to simulate complete fluoroscopic and cineographic representations of all necessary angulations. A wide variety of menu options for wires, catheters, balloons and stents enables the physician to select the necessary tools required to complete the procedure. The physician is able to focus on the particular nuances and specifics of catheter shapes and manipulation necessary to achieve cannulation from this alternate access site. New software modifications, that are currently being tested, will challenge the physician to overcome situations particular to circumstances which may occur in real cases (i.e. spasm, anatomical radial variants, anatomical subclavian variants and particular habetics necessary in these types of procedures). Progress is monitored and reported on in a final case report. As an additional teaching tool, the learner is able to select a 3D mode, which permits visualization of the entire coronary tree in any angulation; an excellent teaching tool for new cardiac fellows.

These simulators have now been in use around the world, helping to train and educate physicians to the transradial technique. Recently, the U.S. division of Terumo joined its international counterparts in this effort and it too is developing programs in concert with institutions across the country to deliver programs to train physicians in radial access. With the lack of education and training being cited as one of the key reasons radial access is not utilized more, Terumo is dedicating resources to help meet this challenge by providing simulation training as an adjunct to the theoretical and practical training necessary to learn radial access. There does appear to be a ground swell of interest in radial access and this author is optimistic that we will see steady increase in its use throughout the United States. There are just far too many factors that support its use (i.e. increased PVD, obesity, etc.).

Will simulators make a difference? There is no doubt that the various medical specialties are looking to simulation training as a means to further enhance the experience of their specific procedural practices. Simulator training should inherently speed the adoption of learning and perhaps we will see greater adoption of transradial within the United States.

For more information about transradial and radial simulation, please contact: Gary Clifton, Gary.clifton@terumomedical.com