Keywords
chemoembolization - liver tumors - transarterial - transradial
Transarterial embolization for primary and secondary liver tumors is proven as a safe
and effective technique.[1]
[2] Traditionally, these procedures are performed via femoral artery access (TFA) in
most cases.[3]
[4]
[5] Transradial arterial access (TRA) has emerged as a valid alternative to TFA in recent
times. TRA is widely used in coronary arterial interventions including coronary angioplasty
and stenting.[6]
[7] Earlier ambulation with shorter monitoring post procedure, shorter hospital stay,
and potentially reduced bleeding risks make TRA an attractive alternative to TFA.
Nevertheless, TRA is under-utilized in non-coronary interventions due to perceived
misconceptions such as increased radiation exposure, prolonged procedure time, and
inability to manage complex vascular anatomic variations. Further concerns include
less familiarity, a longer learning curve, and potentially higher risk for stroke.[8]
[9]
[10] Only limited studies in the literature have compared TRA and TFA in patients undergoing
transarterial embolization of hepatic tumours.[11]
[12]
[13]
[14] This study aims to assess the efficacy and safety of TRA, and compare it to TFA,
as performed by a single operator.
Materials and Methods
This study was a retrospective, single-center comparison of TFA and TRA in patients
undergoing transarterial hepatic tumor embolizations. The study was conducted in compliance
with the principles and protocols stated in the Declaration of Helsinki, in accordance
with the International Conference on Harmonization Harmonized Tripartite Guideline
for Good Clinical Practice. The study was also approved by the local ethics committee
and the institutional review board.
Written informed consent was obtained from all patients, with a specific mention on
the use of TRA. Modified Barbeau's test and ultrasound assessment of the left radial
artery diameter were used to select patients for TRA ([Table 1]). The initial 10 cases were excluded from the study to allow for procedure standardization
and learning curve.
Table 1
Conventional hepatic arterial anatomy from celiac trunk, variant anatomy to include
replaced/accessory hepatic arteries
|
Parameter
|
TR access (N = 58)
|
TF access (N = 44)
|
P-value
|
|
Age (y)
|
66 (40–83)
|
69 (42–86)
|
0.053
|
|
M:F
|
40:6
|
29:15
|
0.020
|
|
Anatomical variations
(conventional: variant arterial anatomy)
|
46:12
|
36:9
|
0.067
|
|
No. of lesions (solitary: Multiple)
|
|
|
0.518
|
|
Injection points (solitary: multiple)
|
39:19
|
33:11
|
0.676
|
|
Fluoroscreening time (min)
|
15.86 (5.57–35.54)
|
17.33 (4.33–39.1)
|
0.639
|
|
Patient dose (mGycm2)
|
187953 (17242–552534)
|
167235 (15857–716082)
|
0.676
|
|
Contrast volume (mL)
|
65 (15–107)
|
75 (35–140)
|
0.668
|
|
Technical success
|
57 (58)–98.2%
|
44(44)-100%
|
0.165
|
|
Complications
|
5 (58)
|
1 (44)
|
0.055
|
Completing trans-arterial tumor embolization with the first arterial access was defined
as a successful technical outcome. Intraprocedural conversion rate, defined as a need
for second or an alternative arterial access either due to intraprocedural difficulties
or major access site complication was deemed as a technical failure. Adverse events,
including access site complications, were assessed according to the Society of Interventional
Radiology (SIR) clinical practice guidelines.[15]
[16] Neurologic events after the procedure, including transient ischemic attacks, reversible
ischemic neurologic deficits, and stroke, defined as a new, persistent neurologic
disability lasting > 24 hours, were also recorded.
Other procedural variables such as screening time, radiation dose, contrast material
volume, were also analyzed as secondary endpoints for comparison. Post procedural
ambulation was assessed in angio suite recovery as time from removal of vascular access
sheath to ability to ambulate freely.
A subset of patients was asked about preference of vascular access and their response
noted in the operation notes. This allowed us to ascertain patient preference for
TRA.[17] Verbal confirmation of access site preference in IR recovery done for a subset of
patients in the study group (with prior TFA experience, all 4 patients in the group
opted for TRA when offered and 12 patients in TRA group chose this when they had repeat
TACE).
All embolizations were performed in an angiographic suite using standard procedural
criteria as established. This included preprocedural optimization, intraprocedural
factors, and postprocedure care.
Radial Access: Left radial artery was always used as the first choice due to its shorter
distance to the target vessel and limited the risk of cerebral emboli or thrombus
formation.
All procedures were performed in the supine position with left arm adducted and placed
over left groin. This allowed easier positioning for cone-beam CT if required. The
radial artery was punctured either in the anatomical snuff box or at the styloid level,
using ultrasound guidance with 1% lignocaine as local anesthesia. Micropuncture access
and the Seldinger technique were used to introduce a 11 cm 4French vascular sheath
(Prelude Ease, Merit Medical, USA). Anticoagulant-vasodilator cocktail (2.5 mg of
verapamil, 2500 IU Heparin and 200 mcg of glyceryl trinitrate) was given through the
sheath after hemodilution to prevent vasospasm and reduce the risk of radial artery
occlusion.
A 125 cm long 4F catheter (MPA1, Cordis or Ultimate 1, Merit Medical, USA) was advanced
over a 0.035 inch-180 cm hydrophilic wire (Terumo medical, Japan) into the upper abdominal
aorta to do selective celiac/superior mesenteric artery cannulation. A 2.7-F microcatheter
(Progreat, Terumo Corp) was used co-axially for superselective catheterization into
the tumor feeding branches for embolization. Microcatheters with a working length
of at least 150 cm were used. Smaller microcatheters were used if super-selective
embolization was required.
Reverse curve/Pigtail catheter and exchange length wires were used to cross anatomically
difficult aortic arches.
Access sheath was removed following the application of radial safeguard (Merit Medical)
with agreed-upon deflation protocol. Deflation was completed in recovery and patients
were allowed ambulation after 1 hour once effects of opioid analgesics had worn off.
Deflated radial safeguard was left in place overnight to manage any delayed access
site bleeding.
Femoral Access: Standard USG-guided retrograde access into the right or left common
femoral artery was obtained using a 4 F 11 cm vascular sheath (Cordis). Curved/reverse
curved 4F catheters (Cobra 2, Simmonds 2 catheter, Cordis) were used for celiac axis/superior
mesenteric artery cannulation. A 2.7 F or smaller microcatheter was used co-axially
into the tumor feeding branches for embolization.
Postprocedural hemostasis was achieved with manual compression in all patients except
for two patients, in whom 6F angioseal closure device was used. Next, 4 hours flat
bed rest followed in the manual compression group and early ambulation (2 hours) in
the ward achieved in those with closure devices.
Statistical Analysis
Statistical analysis was performed with IBM SPSS Statistics for Windows Version 25.0
(IBM Corp, Armonk, New York, USA). Data are presented as mean ± SD. Continuous variables
were tested for normality using the Kolmogorov–Smirnov test and were reported as median
and range. Comparisons between groups were performed using the Mann–Whitney test for
continuous variables and c[2] or Fisher's exact test for categorical data. Differences between two groups were
assessed by Student's t-test. P < 0.05 considered statistically significant.
Results
During the study period, 102 procedures in 90 patients (69 men, 21 women; mean age
66.3 y ± 5.9) were identified, with an age range of 40 to 86 years. All procedures
were performed by a single experienced interventional radiologist (S.K. with 7 years
of experience). All procedures were performed electively. Of the 102 embolizations,
58 were performed by TRA and 44 by TFA.
Various pre- and intra-procedural variables analyzed are listed in [Table 1]. Fluoroscopy time and patient radiation dose were higher in the TRA group, whereas
contrast material volume used was higher in the TFA group, but none of these differences
were statistically significant.
Technical success in the TRA group was 98.2% (57/58). In one patient, due to heavily
calcified aortic arch, the arterial access had to be converted to a femoral access
to allow the procedure to be completed. This gave a crossover rate of 1.7%.
There were no major vascular complications or neurologic events. Six minor complications
were observed—4 puncture site hematomas and 1 self-limiting brachial artery spasm
in the TRA group (8.6%) and 1 puncture site hematoma in the TFA group (2.3%). All
complications were self-limiting without any clinical sequelae and no statistical
difference between the two groups (8.6% vs. 2.3%; P= 0.055). Though no formal post procedural follow-up USG for radial artery patency
was done, in all 12 patients who underwent repeat TRA TACE, the radial arteries were
patent and no documentation of left hand ischemia was noted during data collection.
Early mobilization (<1 h) achieved in all patients in TRA group as expected.
A subset of patients was canvassed regarding their preference of vascular access.
All four patients who had TFA access prior preferred TRA. Also, 12 patients who had
repeat embolizations, during the study period, preferred TRA following previous TRA.
Discussion
Published literature has demonstrated the superiority of TRA compared with TFA for
percutaneous coronary interventions, reducing procedure-related bleeding complications
and improving patient satisfaction.[8]
[9]
[10] Despite the shift in access site preference among interventional cardiologists in
favor of TRA, this technique is not commonly used by interventional radiologists.
Only limited studies in the literature explored the use of trans radial access in
hepatic trans arterial procedures.[11]
[12]
[13]
[14]
[18]
[19]
[20]
[21]
[22]
[23] Our study, by removing the operator bias, effectively compares the technical efficacy
and safety of TRA, in patients undergoing hepatic tumor embolization, with TFA.
Our data demonstrate that hepatic tumor embolization performed through TRA, allows
the same degree of efficacy and flexibility as TFA. We noted no significant difference
in the ability of TRA access to successfully complete the embolization procedure.
There was no observed compromise in the ability to negotiate the anatomical arterial
variations seen in the hepatic circulation via TRA compared to TFA. Some of the previously
published articles concluded that TRA is technically more challenging, resulting in
longer fluoroscopy time and higher radiation dose to the patient.[9]
[12] In our experience, no statistically significant differences were observed in terms
of various procedural variables between TRA and TFA groups. Further, after initial
learning curve period we did not observe any significant differences in terms of pre
procedural patient preparation time.
Our study did not reveal any major vascular or neurologic complications after TRA
with similar rate of minor complications[16] in both access routes. This was recorded in other studies as well.[12]
[14]
[19]
[24] The use of vascular closure devices potentially reduce time to ambulation for TFA,
but additional device related complications and cost[6]
[17] need to be accounted for. Comparatively, the radial safeguard allows hemostasis
without an implanted closure device. Also, it frees up the operator from time spent
in manual hemostasis. Our accelerated deflation protocol, lasting an average 20 to
30 minutes, shortened hemostasis time, even compared to femoral vascular closure devices.
All patients in a small subset of our study group, when asked, opted for TRA when
repeat TACE procedures done for them.
The main limitation of the present study is its retrospective nature. However, procedures
were done by a single operator and a standardized protocol followed in all cases,
hence, this might negate the bias. Another potential limitation could be the lack
of appropriate neurologic follow-up to detect subclinical neurologic events. However,
recent literature on the use of TRA for neurological interventions has established
safety in this regard.[25]
Based on its advantages, TRA seems to be a promising alternative as a primary arterial
access compared with TFA for hepatic trans-arterial procedures.
In conclusion, this study confirms that TRA is as safe and effective for transarterial
hepatic tumor embolization, as is TFA. TRA provides improved patient comfort, allows
early ambulation, and is associated with higher patient preference. Future randomized
prospective studies performed on larger populations, involving specific clinical scenarios,
will be required, to thoroughly evaluate the effect of the arterial access choice
on clinical outcomes.
