The Future of Neurointervention is Transradial Access

Abstract

In recent years, the transradial access (TRA) approach
has become an alternative to the transfemoral access
(TFA) approach for various neurointerventional proce‐
dures. Following the earlier cardiac and peripheral inter‐
ventional experience, the TRA approach offers several
advantages with fewer complications when compared to
the traditional TFA approach [1]. The presence of sys‐
temic anticoagulation or the use of dual antiplatelet ther‐
apy makes the TRA a preferred approach, given the
easily accessible site for compression without the risk of
masked and at times massive hematomas in the retroper‐
itoneum. The presence of a distal palmar collateral
arcade makes the risk of downstream ischemia improba‐
ble. Moreover, its preprocedure evaluation with the
Allen’s test or the more novel Barbeau test using the
pulse oximetry confers assurance to the operator. The
disposition of the arterial anatomy in the upper limb
makes the endovascular navigation into the posterior
cerebral circulation a more natural route into the ipsilat‐
eral vertebral artery. The TRA approach has shown to
decrease access times in the acute posterior circulation
intervention [2]. Finally, the TRA approach is more like‐
able by patients, providing superior convenience and
patient satisfaction with faster recovery times [3].
In the present issue of the Journal of Vascular and Inter‐
ventional Neurology, Ortega-Gutierrez et al. [4] have
presented the article on “Transradial Access: A Feasible
and Safe Approach to Neuroendovascular Procedures”.
This is a single-center experience of the TRA approach
for neurointerventional procedures carried out at the
University of Iowa Medical Center between 2015 and
2019. A total of 27 patients underwent diagnostic and
therapeutic interventions using the TRA approach. In
almost two-thirds of the sampled patients, the TRA
approach was used as an alternative to a previously
attempted catheterization of the supraaortic arteries via
the TFA approach. Unfortunately, the TRA approach
resulted in a serious complication with a forearm com‐
partment syndrome that required emergent fasciotomy in
one patient. In summary, the neurointerventions using
the TRA approach were successfully completed and well
tolerated with a low complication rate.

The TRA approach for neurointerventional procedures is
a successful alternative to the TFA approach, and it is
gaining more acceptance in younger generations of neu‐
rointerventionalists. However, there are some concerns
with the use of the TRA approach. One important con‐
cern is the risk of radial artery occlusion. The operator
should also remember that just the presence of a pulse
on follow-up visit does not rule out radial artery occlu‐
sion. Radial artery occlusion precludes its future use for
percutaneous access. The known factors associated with
the radial occlusion are long procedural times, large bore
sheaths, and longer and higher pressures during hemo‐
stasis. More investigations are needed to understand this
complication in order to design strategies to minimize
the risk. Considerations during the access have been the
use of the distal TRA or snuffbox technique [5] or the
radial artery diameter measurement [6], with a reduced
risk of occlusion when the ratio between the radial artery
diameter and the outer diameter of the catheter was
>1.0. The use of the intraarterial or topical administra‐
tion of vasodilators has not demonstrated to reduce this
risk, but instead it has shown to decrease the risk of vas‐
ospasm. There is also variability in the use of combina‐
tions of vasodilators and dosages. During hemostasis,
some techniques have demonstrated decreased risks of
radial artery occlusion in the cardiology literature stud‐
ies, patent hemostasis (hemostasis while allowing flow
through the radial artery), usually by reducing the com‐
pression pressure or facilitated with the intermittent
simultaneous ulnar compression [7,8].
Finally, it is expected that the industry will parallel the
interest shown by the neurointerventionalists and will
study and design devices to better suit the TRA
approach. For the reasons mentioned earlier, we strongly
believe that in the near future the TRA approach for
neurointerventional procedures will be the norm rather
than the alternative.