Review for 10.1186/s12876-023-02646-1 (2023)

Title: Transradial versus Transfemoral Approach for TACE: A Retrospective Study
Version: 1 Date: 17 Nov 2022
Reviewer's report:
The authors chose a great subject to study as this is an important topic in locoregional therapy
for hepatic malignancies.  There have been studies on the benefits of transradial approach in
other procedures in interventional radiology and it is interesting to see the comparison between
TR and TF in chemoembolization.
It is understood that this study is retrospective in nature so many of the observations are limited
by the nature of this study. That being said, these are some comments/revisions for the study:
-In the study selection, there appear to be more patients in the FA group with tumors larger
than 5 cm compared to the RA group (86 vs. 62). There are also more patients in the FA
group with higher AFP. Although there was no statistical difference in Table 1, could these be
further stratified or what would the results be if each were looked at individually (for example,
comparing results in only in less than 5 cm vs greater than 5 cm, etc.)
-Comment whether evaluation using RECIST and mRECIST was performed by independent
radiologist or interventional radiologist as this could introduce bias. Were these evaluation
blinded to the route of procedure?
-Please provide the actual numbers for the length of stay. It seems that the average length was
several days in both arms, which is atypical for normal TACE procedure, but this might be
standard of care at this institution. This should be addressed in the discussion why length of
stay was so long
-Please clarify what “arterial spasm” means. Are we talking about arterial spasm at the access
site (either radial artery or femoral artery) or the site of treatment (celiac artery, hepatic arteries,
etc.)? If the authors mean access site spasm: were access site arteriograms performed in both
the FA and RA groups consistently? If not, then this is not a valid measurement as there would
be no documentation of spasm in the radial artery.
- The authors mention that the post-operative symptoms and discomfort could be due to delayed
ambulation in the FA group. What was the method of hemostasis in the FA and TA group?
Typically, manual compression for femoral access is 4 hours bedrest, although this may be
different at different institutions. Were closure devices used? This should be clarified in the
discussion and could potentially affect the conclusions drawn from safety data.
-In the discussion, the authors present the idea that there is a better tumor response to TACE
in the RA group due to less arterial spasm, which improves arteriography and subsequent
chemoembolization. The authors need to specify the location of the arterial spasm earlier in the
manuscript. This may also be a confusing conclusion to draw as the amount of lipiodol and
chemo-mixture was the same between the two groups in Table 2 (although perhaps this was not
powered for that analysis). The improved tumor response is indeed a very interesting finding,
but the discussion does not seem to provide enough clarity why the authors believe this to be
the case. Ultimately, they may conclude that it needs further investigation and this study is not
designed to answer that question, but it needs to be explicitly stated
Overall, this is a good study with a good number of subjects. If the previous comments are
addressed and advised, it could spur further prospective studies that could have very interesting
conclusions.