Title: Surface Area Outcomes in EUS-Guided Liver Biopsy: A Comparative Study of Franseen
and Fork-tip Needles
Version: 2 Date: 23 Jan 2025
Reviewer's report:
I agree with the authors that reliance on total specimen length (TSL) is a limitation, and length
of the longest piece is probably better.  However, it is not clear to me why the “surface area”
is a better metric than, for example, length of the longest piece (LLP), or even total specimen
length. The surface area is closer to TSL than LLP and as such, has the same limitations as TSL.
The surface area is basically 2 times the specimen length, with a little more added on the ends.
So again, I am not sure of the advantage of surface area.
The use of whole slide imaging (ESI) is not a novel approach; it has been used extensive in
most of the prospective randomized studies comparing needle types and sizes, wet vs dry, and
number of passes.
It is interesting that the authors used “portal tracts” and not “complete portal tracts”, which has
been the standard in the literature on this subject. Is there a reason this was done?  This makes
the results harder to compare with portal triad data already in the literature.
It does not appear that a power analysis was done to understand how many patients would be
needed in each arm of the study.  As a result, it is not possible compare the two needles in terms
of adequacy or efficacy.
Figure 1 legend.  The description of the image is for the left pane only; the right panel is Doppler
and this is not indicated in the legend.  In any case, you probably only need a single image,
not both.
Title: Surface Area Outcomes in EUS-Guided Liver Biopsy: A Comparative Study of Franseen
and Fork-tip Needles
Version: 2 Date: 23 Jan 2025
Reviewer's report:
I agree with the authors that reliance on total specimen length (TSL) is a limitation, and length
of the longest piece is probably better.  However, it is not clear to me why the “surface area”
is a better metric than, for example, length of the longest piece (LLP), or even total specimen
length. The surface area is closer to TSL than LLP and as such, has the same limitations as TSL.
The surface area is basically 2 times the specimen length, with a little more added on the ends.
So again, I am not sure of the advantage of surface area.
The use of whole slide imaging (ESI) is not a novel approach; it has been used extensive in
most of the prospective randomized studies comparing needle types and sizes, wet vs dry, and
number of passes.
It is interesting that the authors used “portal tracts” and not “complete portal tracts”, which has
been the standard in the literature on this subject. Is there a reason this was done?  This makes
the results harder to compare with portal triad data already in the literature.
It does not appear that a power analysis was done to understand how many patients would be
needed in each arm of the study.  As a result, it is not possible compare the two needles in terms
of adequacy or efficacy.
Figure 1 legend.  The description of the image is for the left pane only; the right panel is Doppler
and this is not indicated in the legend.  In any case, you probably only need a single image,
not both.
Please review this paper.
user
Title: Surface Area Outcomes in EUS-Guided Liver Biopsy: A Comparative Study of Franseen
and Fork-tip Needles
Version: 2 Date: 23 Jan 2025
Reviewer's report:
I agree with the authors that reliance on total specimen length (TSL) is a limitation, and length
of the longest piece is probably better.  However, it is not clear to me why the “surface area”
is a better metric than, for example, length of the longest piece (LLP), or even total specimen
length. The surface area is closer to TSL than LLP and as such, has the same limitations as TSL.
The surface area is basically 2 times the specimen length, with a little more added on the ends.
So again, I am not sure of the advantage of surface area.
The use of whole slide imaging (ESI) is not a novel approach; it has been used extensive in
most of the prospective randomized studies comparing needle types and sizes, wet vs dry, and
number of passes.
It is interesting that the authors used “portal tracts” and not “complete portal tracts”, which has
been the standard in the literature on this subject. Is there a reason this was done?  This makes
the results harder to compare with portal triad data already in the literature.
It does not appear that a power analysis was done to understand how many patients would be
needed in each arm of the study.  As a result, it is not possible compare the two needles in terms
of adequacy or efficacy.
Figure 1 legend.  The description of the image is for the left pane only; the right panel is Doppler
and this is not indicated in the legend.  In any case, you probably only need a single image,
not both.
assistant