Radial Artery Catheterization: The way to go
Last month, I visited Dr. Olivier Bertrand at Laval Hospital in Quebec City, Canada, to present a talk on coronary physiology. He and his team showed me their lab and method of performing radial artery catheterization for their 10,000 patients of 2008-2009, with 3,500 percutaneous coronary interventions (PCIs) from the same approach. They reported no retroperitoneal hematomas, femoral pseudo aneurysms, fistula or femoral artery bleeds, occlusions or emboli. The complications from radial artery access are trivial compared to femoral, with
What are the data to support radial artery as the superior method? The data on this issue have been coming forward for the last decade. Jolly et al1 compared radial to femoral vascular access for PCI by examining studies reported in the Medline, Embase, and Central database from 1980 to 2008 and reviewed abstracts from 2005 to 2008. Randomized trials comparing radial versus femoral access for intervention which reported the endpoints were included. By meta-analysis, radial artery access reduced major bleeding 73% compared to femoral access, (0.05% vs. 2.3%, p
While the obvious benefits of the radial access are clear in many defined subsets, it has not overcome the tradition and practice of femoral access in this country. The reasons for this reluctance include operators’ actual and perceived increased procedure and fluoro time, and needed skill level. Without specialized training, some of the more difficult patients who have tortuous subclavian systems, small radial arteries or anatomical variants (e.g. an ulnar loop) may produce prolonged, if not unsuccessful, access. These problems of technique are overcome with increased experience, much like that of difficulties encountered from the femoral approach.
Too much radiation?
“I’m worried about increased x-ray exposure,” one operator informed me. Keith G. Oldroyd, MD (Hons), FSCAI, FRCP (Glasg), consultant interventional cardiologist at the Western Infirmary, Glasgow, countered this argument. “The published observational series of femoral access report values for patient and operator radiation exposure during diagnostic and interventional procedures may vary by a factor of ten in different studies. Observational studies that have compared radial and femoral access report a much smaller difference with a reported increase in radiation exposure of up to twofold. A simplistic view would be that radial access increases radiation exposure, but not by nearly as much as having your procedure done by some [less accomplished — my addition] femoral operators. There is no standardization of radiation protection practice in these studies, so they are not comparing like with like, which makes the reliability of the data for comparative purposes dubious.
“In the comparative radial/femoral studies, expert femoral operators are compared with far less accomplished radial operators, and the reported difference is simply a learning curve phenomenon — it is analogous to comparing radiation exposure values for a first-year trainee with a fully accredited consultant. In our institution, we have compared a high-volume radial operator with a high-volume femoral operator using a fixed view sequence and optimal radiation protection strategy for first-time diagnostic angiograms — there is no difference in operator or patient radiation exposure — i.e. when you take the learning curve out of the equation, there is no increase in radiation exposure for radial access. Radiation exposure thus appears to be the last stand of the femoral diehards. The slow acceptance of radial access in the USA is astonishing, given that the most common complication of a cardiac procedure relates to the femoral access point, and that vascular closure devices (in meta-analysis of randomized trials) have no effect on reducing this complication rate (and may increase it).”
Further support can be gleaned from Rao et al’s paper “Trends in the Prevalence and Outcomes of Radial and Femoral Approaches to Percutaneous Coronary Intervention: A Report From the National Cardiovascular Data Registry”2, wherein they report the volume of radial PCIs went from approximately 1.3% to 3.5% by the first quarter of 2007 for those participating in the American College of Cardiology —National Cardiovascular Data Registry (ACC-NCDR) database. In speaking with colleagues, Dr. Zoltan Turi reminded me that “like anything else, there are a lot of ways to get into trouble [when starting radial cases], but the hardware has become much better in the last decade. My five cents is you should do them all the time, or not at all.”
As I brought up this topic with colleagues, femoral advocates outnumbered the radial proponents. Reasons given were often the same, spelling out a common thread: 1) We still are predominantly a femoral access lab, related to the fact that we train fellows and they need to first learn femoral access approach; 2) We have many patients with prior bypass surgery; 3) Femoral is faster; 4) More options for guide sizes, etc., for PCI with femoral; 5) Keeping radial artery pristine for coronary artery bypass graft surgery (CABG).
One of my European colleagues commented that the radial approach is popular, but varies widely among countries. He has heard that radial approach is often age-dependent, with older interventionalists keeping to the femoral approach. It has become clear that good operators and labs should be very good at both — radialists should be better femoralists and vice versa. Another European interventionalist told me, “The main reasons why we don't do it more are a mix of laziness, habits, and misconception on the length of the procedures. What we realized is that if you do not increase the number of radials above a certain threshold (I would guess at least 30%), you never get everyone in the lab used to it and, thus, the procedure remains ‘the exception,’ and thus it appears to be more complicated.”
Many femoralists state that, “I only do radial if there is no femoral access, in very obese patients, and sometimes for a LIMA [left internal mammary artery graft]. The femoral approach is easier, quicker, [and offers] less radiation and better images because my skills in manipulating catheters are better from the groin. Moreover, if you need to exchange for large guiding and special equipment, it is easier.”
One young Pennsylvania radialist noted, “We have fellows in training as well. They are actually quicker to pick up the technique than one would expect as they have no preconceived notions on how to do things otherwise. When they do it [radial approach] frequently rather than in special circumstances, they become quite adept. We place the arm next to the body, next to the groin so the radiation is only minimally increased. You can use up to a 7F for men and 6F for females, although I do many 5F interventions via the radial. There is even data on using the radials after angiography for CABG without problems.”
I’ve summarized some thoughts on the differences between radial and femoral approaches (Table 1). We should be performing the best procedure for the appropriate patient with the best outcomes, lowest complications, lowest cost and most patient comfort. For these reasons, I think most caths should be done radially. Our technique must rise to the occasion and our personal reasons for avoiding the best for our patients should be outgrown. The younger generation of invasive interventionalists should be able to do procedures from both approaches with the same facility and safety. I also recommend review of the articles previously and recently published in Cath Lab Digest and The Journal of Invasive Cardiology (see below). It’s hard not to see that the future of cardiac cath is on your wrist.