Effect on hand function of distal transradial access for angiography and angioplasty

Distal radial access (dTRA) in the anatomical snuffbox to retrogradely open
occluded radial arteries has first been described by Dr. Babunashvili in 2011
(1). Later, Dr. Kaledin reported distal radial access as default technique for
coronary access (2). During the 3rd Isfahan Transradial Course, Dr. Roghani,
interventional cardiologist Isfahan University of Medical Sciences in Iran,
demonstrated advantages of alternative distal access sites at the volar and the
palmar sides of the hand. Based on this information Kiemeneij modified the
technique to left distal transradial access (ldTRA) as a default procedure in
right handed patients (3). Not even a year later, predominantly due to the
influence of social media platforms as Twitter, the ldTRA is pioneered in 4
countries. The rapid and progressive acceptance of this new technique is
explained by the many advantages for patients and doctors, such as the
availability of 2 new entry sites in the arms, patient comfort, operator
comfort and an expected lower rate of radial artery occlusions. However, not
much is known yet about the effect of dTRA on hand function. Theoretically,
pinch grip cannot be affected since the thenar muscles and the finger muscles
all get their nervous innervation and blood supply from nerves and vessels at
the palmar side of the hand, not related to the anatomy of the anatomical
snuffbox. However, frequent mis-puncture and/or hematoma formation and
prolonged total hemostatic compression in the anatomical snuffbox may have the
risk of sensory nerve damage and distal embolization, resulting in sensory loss
and ischemia of the dorsal of the radial three fingers, thenar ischemia and
scaphoid hypoperfusion. Sensory function of part of the dorsal side of the hand
can become affected by potential damage of the superficial branch of the radial
artery which runs through the snuffbox. Occlusion of the distal radial artery
may result in ischemia of the dorsal sides of thumb, index-and middle fingers.
Although none of these complications have been reported, it is justified to
perform a systematic follow-up of hand function before and after dRA.
Information on these important endpoints will also contribute to refine the
current technique, in order to obtain the best possible outcomes.

The objective is to make an inventory of hand function before and after dTRA.
In addition secondary endpoints are measured like success rates and
complications of distal radial access for coronary angiography and
interventions.

The study design is a prospective non-randomized multicentre inventory of
outcome of distal transradial coronary angiography and/or intervention. Hand
function tests (Levine Katz and DASH questionnaires, VAS score, pinch grip test
and sensory test with Semmes Weinstein filaments) will be performed at baseline
and at one month.

Nature and extent of the burden and risks associated with participation,
benefit and group relatedness: On the same day of a previously planned coronary
angiography and on the outpatient follow-up appointment, patients will undergo
assessment using questionnaires and other hand function tests. The burden will
be very mild as all tests are non-invasive and will take but short time to
perform. No change will occur on the intended therapy for the patients.
Coronary angiogram and/or angioplasty will be performed as indicated on
discretion of the physician in charge of treating the patient. The puncture
site, also referred to as access site, will be according to this protocol the
distal part of radial artery at the anatomical snuff-box. The standard
technique of gaining arterial access will be exercised. In case arterial access
is not obtained in the distal radial region, the performing operator will be
able to shift to the a more proximal access site on the radial artery. All
tests and procedures involved in this protocol are already part of standard
patient care which are regularly performed by other disciplines such as
neurologists and physiotherapists and are considered safe. Possible benefits
include establishing more insight about the effect on hand function of a rather
new access site for performing angiography and/or angioplasty. This access site
is more distal (distal radial approach). This access site inevitably imply
less burden for the vascular system. In addition, in case the distal (radial)
access site occludes, the forearm radial artery will remain patent because
distal flow is guaranteed by the presence of the superficial palmar branch. We
consider it very important to gain more knowledge about this rather new
technique (distal access site) as it bears a lot of potential benefits for
patients and doctors. Such benefits include less risk of bleeding, the
possibility of undergoing angiography via the left hand, ergonomically
comfortably for the operator. Possible risks are sensibility loss of part of
the hand if the cutaneous nerve running in the anatomical snuffbox becomes
damaged. Furthermore, distal embolization can result in digital ischemia.
Occlusion of the branch supplying the scaphoid bone can result in bone
necrosis. Based on reported data, these serious complications have not been
described. Thus is this research project undertaken.