Keywords
radial artery - access - technique
Introduction
Hepatobiliary interventions such as transarterial chemoembolization (TACE), transarterial
radio embolization (TARE), and gastrointestinal interventions such as mesenteric arterial
stenting are generally performed via a transfemoral arterial approach. This requires
the patient to be on strict bedrest post procedure. Radial arterial access is commonly
undertaken during coronary interventions. It has multitude of advantages, including
early patient ambulation following the procedure and increased patient satisfaction.
Cooper et al showed that patients who underwent arterial interventions through a radial
artery access had better social function and were able to walk and use the bathroom
early compared with those who underwent femoral arterial access at 1 and 7 days after
the procedure.[1] There is also a reduced risk of bleeding with radial artery access.[2] In addition, radial artery access may be more beneficial in patients who suffer
from back pain or may have nausea and vomiting post interventions (e.g., following
TACE). The authors have been performing peripheral arterial interventions through
a radial arterial access since 2015. The aim of this study was to report outcomes
of patients who underwent radial arterial access during arterial interventions of
the hepatobiliary and gastrointestinal system.
Materials and Methods
Patients who underwent hepatobiliary and gastrointestinal arterial interventions via
a radial arterial access were identified by reviewing the interventional database.
The clinical notes of these patients were reviewed to identify whether any complications
were encountered and their eventual outcome. Any procedural modifications or conversion
to the standard femoral arterial access approach were also noted. Patients were consented
after explaining the procedure along with possible complications.
Barbeau test was used to assess the patency of the palmar arch prior to obtaining
a radial artery access. The patient was positioned supine on the interventional radiology
(IR) table, with the upper limb being placed on a movable side board. The wrist was
then hyperextended with the help of folded towel along the dorsal aspect of the distal
forearm. The fingers were strapped to the side board ([Fig. 1]). The puncture site was cleaned and draped as per institutional protocol. The puncture
site was two/three finger breadths proximal to the distal wrist/palmar crease ([Fig. 2]). This ensured that the puncture was not through the tough fascial layers of the
flexor retinaculum. The radial artery was undertaken under ultrasound guidance using
Seldinger technique.
Fig. 1 Position of the hand prior to radial artery puncture. The wrist is hyperextended
and taped to the side board to prevent movement.
Fig. 2 Puncture site is demonstrated. This is two/three finger breadths proximal to the
palmar crease.
Once access was obtained, “radial cocktail” was injected via the sheath side port.
The cocktail is a mixture consisting of 100 µg of nitroglycerine and 3,000 IU of heparin.
Long catheters (100 or 125 cm, 4F or 5F Cobra/multipurpose/vertebral catheters) were
used to cannulate the celiac artery or the superior mesenteric artery. To secure hemostasis,
a tight bandage was applied at the puncture site (transradial band/wrist band) following
removal of the sheath. The bandage was kept in place for 2 hours. Once hemostasis
was secured, the band was removed. Patients were nursed in an upright or semirecumbent
position and were encouraged to ambulate at the earliest possible moment. Some were
advised bedrest in view of the anticipation when a large portion of the liver was
embolized.
Results
A radial artery access was obtained in 46 occasions in 32 patients. The radial artery
was accessed on four occasions in one patient and on three occasions in another patient.
Seven patients had radial artery accessed on two occasions. Most patients were men
(85%). The average age of the patient was 60 years (range: 32–83 years). The right
radial artery was accessed in 87% of the occasions. The procedures performed included
TACE in 85%, planning angiography prior to TARE in 6.5%, and TARE in 6.5%. In one
patient, the radial artery was accessed for superior mesenteric artery stenting. The
individual Barbeau scores were not recorded. The patients were followed up for an
average of 4 months (range: 1–20 months). There was no conversion from a radial access
to a femoral access.
The technical success rate was 98.7%. In one patient, a radial artery access was obtained
for a planned angioplasty and stent placement for superior mesenteric artery stenosis.
However, the arterial access was abandoned due to severe art erial spasm. This was
the only complication encountered in this patient cohort. In spite of adequate analgesia,
the spasm was not alleviated. As the patient was getting restless and a possible surgical
option was being considered, the patient was intubated. The spasm subsided without
any further medical or surgical interventions, and the catheter was removed. Given
the angle of the origin of the superior mesenteric artery to the aorta, a femoral
approach was considered challenging. The patient underwent a successful stenting of
the superior mesenteric artery at a later date via a brachial artery approach after
surgical exposure of the artery. In patients who had the radial artery accessed on
multiple occasions, there was no incidence of arterial occlusion or injury. Irrespective
of whether the right or left radial artery was accessed, standard length catheters
were not sufficient and longer catheters (> 100 cm) were needed to catheterize the
visceral arteries.
Discussion
Since its description in 1989, the radial artery access for coronary interventions
has increased over the past two decades.[2] It has become the access of choice for primary coronary interventions (PCIs) in
more than 65% of the cases in the United Kingdom and has recorded a 25% increase in
its utilization every year since 2007.[3] Various studies have demonstrated the advantages of radial artery access over femoral
artery acc ess. The Radial Versus Femoral Randomized Investigation in ST-Elevation
Acute Coronary Syndrome (RIFLE) study found statistical reduction in access site bleeding
complications and overall adverse events with radial artery approach in their review
of more than 1,000 patients undergoing PCI.[4] In comparison to the femoral artery, the radial artery is more superficial and there
are no important structures near by, which are likely to be injured during arterial
access.[5] In addition, its superficial position makes it easy to achieve hemostasis by manual
compression, thus obviating the need for closure devices. It is beneficial in obese
patients, in whom the radial artery access has been shown to reduce the risk of bleeding.
It also contributes to patient comfort with reduced hospital costs.[6]
Selection of the radial artery for establishment of the access requires the operator
to ensure that the flow of the hand will not be compromised if the radial artery is
subsequently damaged. The Barbeau test is used to assess arch patency as it is more
sensitive than the modified Allen's test.[7] A radial artery diameter of 2 mm and above is considered ideal to undertake radial
arterial access.[5] Some authors consider 3 mm as the minimum diameter.[8] Most radial arterial accesses can accommodate sheaths ranging from 4F to 7F.[5] However, the use of larger sheaths is associated with a greater risk of arterial
occlusion.[9] If guide catheters are to be used, sheathless guides can be used. However, other
strategies are also needed to prevent arterial occlusion as discussed latter in the
article.[10] Use of hydrophilic sheaths is recommended. Newer sheaths are available that have
smaller outer diameter but accommodate a larger catheter. For example, hydrophilic
4F and 5F sheaths can accommodate 5F and 6F catheters, respectively.[5]
Traditionally the cardiologists prefer to use the right radial artery. In their practice,
the authors initially started using the right side and subsequently shifted to the
left side. Access via the left radial artery reduces the number of cranial vessels
that need to be traversed. Only the left vertebral artery is crossed. Though either
approach is associated with a very small but significant risk of neurologic insult
(~0.11%), that risk is further reduced using a left radial approach.[8] Further studies are needed to assess this risk in patients undergoing noncoronary
interventions.
Access to the radial artery can be undertaken either by palpation or under ultrasound
guidance. Seto et al demonstrated that the first-time success rate and time to secure
the access were higher in the group of patient who underwent ultrasound-guided puncture.[11] Once access is obtained, a radial cocktail is injected. The purpose of this cocktail
is to reduce the risk of spasm and thrombosis. Caution should be exercised when using
verapamil in patient with preexisting cardiac pathology. Some authors also add 2.5
mg of verapamil and lidocaine. The technical success rate in this study was approximately
98%. This is comparable to that reported by Posham et al.[12] However, they had a more varied case mix ranging from onco-intervention to fibroid
and peripheral arterial intervention. The authors’ study was confined to onco-interventional
cases and one case of mesenteric vessel intervention. Though none of the patients
required crossover to femoral arterial access, one patient required brachial artery
access after abandoning the radial artery access that was complicated by severe radial
artery spasm.
When the authors started obtaining radial artery access for visceral arterial interventions,
they found that the standard catheters were of insufficient length. Longer catheters
and sheaths are required to ensure adequate access and stability. The catheter should
be at least 150 cm long to enable selective catheterization of the target vessels.
Though traditional catheter shapes (cobra/multipurpose/vertebral catheters) are unstable,
Berenstein, Sarah, and Tiger catheters offer better stability. When a stable position
could not be achieved with traditional catheter shapes, an additional operator had
to maintain the catheter position.
The authors found negotiating an unfolded aortic arch difficult, especially with right
radial artery access. They found that this required additional equipment, increased
radiation burden, and potentially an additional operator. Access via the left radial
artery access avoids the disadvantages secondary to a redundant aortic arch. The authors
also found when cannulating the celiac artery or superior mesenteric artery, the catheter
tended to face posteriorly in the aorta and needed to be turned anteriorly. This can
be challenging in anteroposterior/oblique projections. Hence a lateral projection
may be needed to cannulate the origins, thereby increasing exposure time and the radiation
dose.
Compared with the femoral arterial access, the radial artery access is safer with
reduced complication rates. In their review of 1,000 noncoronary cases, Posham et
al reported a complication rate of 2.5% with only two major complications.[12] The most common complication was minor hematoma. Other rarer complications included
radial artery pseudoaneurysm, vessel perforation, radial arteritis, arterial spasm,
and dissection.[5] They were no major complications in the authors’ study group. Radial artery occlusion
is a rare complication, and it tends to be asymptomatic given the dual nature of the
blood supply to the hand. This risk can be reduced by using smaller-sized sheaths,
increasing the heparin dose, and using hydrophilic sheaths.[5]
[13] Pancholy et al recommended the use of patent hemostasis technique to prevent arterial
occlusion.[13] In their series, the authors had only one complication of severe arterial spasm
that necessitated the procedure to be cancelled. The authors did not convert it to
a femoral approach, as the vascular anatomy was not suitable for a femoral approach.
On subsequent review, the artery was approximately 2 mm in diameter with wall calcification.
Both of these are the recognized causes of difficult radial artery access.
One of the limitations to this study is its small size. However, the initial outcomes
are promising and comparable to other studies. Though widely reported, the authors
did not assess patient satisfaction scores in this study.
Conclusion
Radial artery access for visceral arterial interventions is safe and technically feasible.
Longer catheters, guidewires, and, at times, two operators were needed to obtain a
stable catheter position. With increased experience and newer and longer catheters
being available, the authors anticipate more peripheral interventions through a radial
artery access.
