EDITOR’S CORNER
Peter C. Block
Editor-in-Chief, CardioSource WorldNews: Interventions
Of Babies and Bathwater
Let’s Not Throw Out Femoral Arterial Access
I
n the catheterization world of arterial access,
revolution is in the air. Transradial (TRA) catheterization and TRA PCI are now widely used throughout the world, and fellows-in-training are keen to list
experience with the radial approach in their personal
summaries. There seems to be a sense that the “new”
site is a hot topic, and interventionalists wear their
TRA credentials like Top Gun insignias. Reports summarizing the virtues of TRA are in the literature,1,2
and, indeed, there are many features that make TRA a
good choice for many patients. If nothing else, patient
demand for, and satisfaction with TRA, may lead
the list. To the lay public, there is something slightly
magical about doing a diagnostic cath or a PCI from
the wrist. In response, cardiologists are indicating that
they plan to increase the number of times they will
perform TRA in the future2 and there are webinars
and mini-courses on how best to do TRA for initiates.
But TRA is not without its critics. I confess to
being wary about abandoning the transfemoral (TF)
approach. Much of that wariness comes from the fact
that a long list of reports (both observational and randomized) of TRA versus TF approaches has produced
mixed messages. Some recent randomized trials have
not been able to demonstrate superiority for TRA
over TF,3,4 making any wholesale conversion to TRA
less than data-driven. There may be any number of
reasons that this is the cased—small numbers, patient
selection bias, restrictive definitions, etc., but the fact is
that there is no large randomized trial that has shown
unequivocal TRA superiority. In addition, TRA is not
without its own difficulties: the small radial artery that
is difficult to access; arterial spasm in the brachio-radial tree, radial anomalies (radial loop, accessory radial
artery), intrathoracic anomalies (bovine arch), need
for smaller catheters, greater difficulty in engaging the
coronaries and graft vessels, familiarity with specialized TRA catheter shapes, and importantly, longer fluoroscopy time and greater radiation dose to both patient
and operator (though experienced operators seem able
to overcome this),5 etc. Dangerous bleeding complications are not in the purview of TF alone and can occur
with TRA (e.g. anterior compartment syndrome from
mid-radial perforation) and the possibility of stroke
from traversing the commonly found plaque at the
innominate bifurcation or from embolic intima carried
from the radial artery is always present.6 Thrombotic
hand ischemia can occur7 as can wrist/hand dysfunction from compression nerve injury.8 FA naysayers are
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CardioSource WorldNews: Interventions
able to list an equally discomfiting list of TF difficulties, and observational studies have even suggested a
mortality benefit for TRA over TF.9
Now in the July issue of JACC: Cardiovascular Interventions, there is a meta-analysis that sheds further
light on this controversy.10 The meta-analysis supports
TRA as the “default” strategy but cites multiple important limitations of which the authors state: “Although
this meta-analysis provides evidence supporting the
superiority of radial approach as compared to femoral
approach, […] differences in absolute event rates between groups were small for several endpoints leading
to a number needed to treat to benefit or harm above
100.” Despite the “strong” and “moderately strong”
conclusions listed in the report, this meta-analysis
carries with it the inherent difficulties of any metaanalysis. To allay these, the authors have used some
unique statistical methods to help their cause. But in
addition to the “usual suspects” of meta-analysis bashing, there are additional potential problems. The studies that were chosen for the meta-analysis are largely
from centers interested in TRA, with expertise that is
not universal. Some of the randomized trials included
were done more than 10 years ago. Techniques, even
for TF approaches, have changed. A majority of the
trials that were included in the analysis used manual
compression for TF hemostasis. That too has changed
in centers in which TF expertise with closure devices
has evolved. It is not my purpose to editorialize the
report, but meta-analyses are fraught with potential
bias, and cannot take the place of well-designed randomized trials.11 For those looking for TRA support in
this controversy, John A. Bittl, MD, in an accompanying, even-handed editorial has approached that.12
In my view, the problem is complex and this
recent meta-analysis does not solve the controversy.
If we abandon TF for TRA, will we be throwing the
baby out with the bathwater? Not everyone is a candidate for TRA. Patients with small radial arteries or
abnormal Allen or oximetry tests or upper-extremity
hemodialysis shunts are not candidates. Use of large
interventional devices > 7Fr or hemodynamic support
devices are unsuitable for TRA, and bail-out situations
for a complication of TRA almost always mean an
urgent TF approach. One can argue that such patients
are a small minority of those having cardiac catheterization or PCI, but they exist in any center. Furthermore, with expansion of transcatheter techniques for
structural heart disease, TF access expertise remains
mandatory, and with it complete understanding of
femoral closure. Just like TRA, TF access and the
understanding of TF catheterization and interventions
require expertise and experience to maximize safety.
The question is how do we manage to be experts
at both? It is easy to say that all catheterizers/interventionalists simply will have to be competent doing
both TRA and TF, but it is likely that maintenance of
competence for both will require more cases per year
than many centers can provide. Choosing specific
physicians to do “only” TF or TRA is an unlikely
scenario, and what happens if a complication requires
a urgent change from TRA to TF? In the movie The
Usual Suspects, Verbal Kint (a.k.a. Keyser Soze) asks
the provocative questions: “How do you shoot the
Devil in the back?... What if you miss?” Mr. Soze was
referring to a fallback position, which is exactly what
every TRA operator needs to have in mind in case
something goes terribly wrong. That is a situation
where lack of TF expertise might add injury to injury.
At this point, the rush to TRA is simply not supported by the data available. What is needed is a wellconceived randomized trial t hat compares TRA with
TF. Exactly how that design might evolve is debatable,
but the inclusion of an arm that mandates an TF
closure device might help us understand what role (if
any) such devices have in helping choose patients for
TF versus TRA. Will such a trial happen? Perhaps, but
funding for such a venture (that will require enrollment of thousands of patients) is a real deterrent. ■
REFERENCES
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4. Rao SV, Hess CN, Barham B, et al. JACC Int. 2014;7:857-67.
5. Jolly SJ, MD, Cairns J, Niemela K, et al. JACC Int.
2013;6(3):258-66.
6. Jaworski C, Brown AJ, Hoole SP, et al. JACC Int.
2015;8(11):177-8.
7. Rademakers LM and Laarman GJ. Neth Heart J.
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8. Gilchrist IC. Cardiac Interventions Today. Jan/Feb 2008.
9. Vorobcsuk A., Konyi A., Aradi D. Am Heart J.
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10. Ferrante G, Rao SV, MD, Jüni P, et al. JACC Int. 2016;doi.
10.1016/j.jcin.2016.04.014
11. LeLorier J, Grégoire G, Benhaddad A, et al. N Engl J Med.
1997;337(8):536-42.
12. Bittl JA. JACC Int. 2016;doi:10.1016jcin.2016.05.026
Peter C. Block, MD, is a professor of medicine and
cardiology at Emory University Hospital and School
of Medicine in Atlanta, GA.
July/August 2016