Reviewer’s report
Title: 
Clinical and endoscopic features of aorto-duodenal fistula resulting in its
definitive diagnosis: an observational study
Version: 
2 
Date: 
21 Dec 2020
Reviewer's report:
I want to thank the authors for the excellent revision they performed on their
paper, which is now much better organized and easy to read. 
I only suggest few minor changes:
- The first part of methods section is a little too much detailed (lines 57 to 61). I
suggest to modify the section as it follows: "The present study examined
patients' baseline clinical and laboratory data, past medical history, endoscopic
and CT scan findings, number of blood transfusions received, definitive
treatment and outcome. Type of scope used during endoscopy, the use of tip
attachments and of marking clips were also collected").
- The definition of shock provided (line 61) is not typical, is it the standard
definition you use in your institution? Usually, hemorrhagic shock is defined in
literature as the combination of systolic blood pressure < 100 mmHg and heart
rate > 100 beats per minute
- Line 66: the sentence "Even then, we did not find any abnormalities" should be
a hypothetical sentence: "If no abnormalities were found even using a tip
attachment, then we changed to pediatric colonoscope PCF-PQ260L…". 
- Specify if the described endoscopic strategy (lines 63-67) is the standard
strategy you follow in your institution for all suspected AUGIB or is specific for
patients with suspected bleeding from deep duodenum (such as patients with
history of aortic pathology)
- Line 68: reference is missing
- I suggest to put baseline characteristics of the patients (lines 104 to 113) at the
beginning of the result section
- Line 99: add the case number in brackets for the patient who died during
endoscopy
- When mentioning that all patients underwent aortic treatment in the past, report
also the mean timing of the intervention with the range (7 months to 13 years
prior). I think it is interesting that ADF could develop after so much different
periods of time (you could also briefly discuss it in the discussion)
- Line 140: reference is missing
- Discussion section should be a little enlarged and reorganized: I suggest to start
discussion with a short sentence about the importance of a prompt diagnosis in
ADF in order to increase chance of definitive treatment and survival; then
discuss the herald bleeding, that can mimic a "normal upper GI bleeding, and the
importance of patient's history of aortic or para-aortic treatments that should
increase the suspicion of ADF even for small, transient bleeding. Then discuss
the difficulty of definitive diagnosis and the frequent need for combined
radiology/endoscopy. 
- In the discussion, you should mention the missing information about timing of
endoscopy as a limitation of the present study. 
- Line 159: reference is missing
- I suggest to modify as follows the first sentence of conclusions: "In a patient
presenting with upper gastrointestinal bleeding, a history of intervention
involving the aorta should increase the suspicion of ADF. A combination of
endoscopy and CT scan is usually necessary to achieve a definitive diagnosis.
- Table 2: change commercial name "loxonin" to loxoprofen
Publons Reviewer Recognition
. Springer Nature can send verification of this
review directly to Publons (a subsidiary of Clarivate Analytics). If you would
like to take advantage of this service, please click on the “Yes” option below.
Your name, email address, title of the reviewed manuscript, name of the journal,
and date of your review submission (the “Review Data”) will then be transmitted
to Publons upon publication of the manuscript. If you have already registered at
Publons, they will notify you of the receipt of this review and update your profile
as per your settings and their policy. If you are not registered with Publons, you
will receive an email from them asking you to register in order for them to be
able to recognize your review on your new profile page. Publons may use the
Review Data to generate derivative metadata for the benefit of Publons and you
as a reviewer, carefully considering the sensitivity of such information. For
example, Publons may verify your record as a reviewer by updating your profile
published on its webservice if you have registered for such service or help
editors to identify candidate reviewers. Please find the details of processing in
Publons’ privacy policy 
https://publons.com/about/terms
Yes
Declaration of competing interests
Please complete a declaration of competing interests, considering the following
questions:
1
. 
Have you in the past five years received reimbursements, fees, funding, or
salary from an organisation that may in any way gain or lose financially
from the publication of this manuscript, either now or in the future?
2
. 
Do you hold any stocks or shares in an organisation that may in any way
gain or lose financially from the publication of this manuscript, either now
or in the future?
3
. 
Do you hold or are you currently applying for any patents relating to the
content of the manuscript?
4
. 
Have you received reimbursements, fees, funding, or salary from an
organization that holds or has applied for patents relating to the content of
the manuscript?
5
. 
Do you have any other financial competing interests?
6
. 
Do you have any non-financial competing interests in relation to this
paper?
If you can answer no to all of the above, write 'I declare that I have no competing
interests' below. If your reply is yes to any, please give details below.
I have no competing interests
Reviewer Publication Consent.
 I agree for my report to be made available
under an Open Access Creative Commons CC-BY License (
http://creativecommons.org/licenses/by/4.0
) if this manuscript is accepted for
publication. Any comments that I do not wish to be included in the published
report have been included as confidential comments to the editor, which will not
be published.
If you are not happy for us to publish this report, please contact the editorial
office before completing the review.
If you wish, you can include your name in your published report. Please note
you must decide whether to include your name at the start of the process and
confirm this decision whenever prompted. If you change your decision later, we
will not be able to publish your name.
I agree to the terms of the CC-BY 4.0 license; please 
do not
 publish my name
with my report. (default)
Is the study design appropriate to answer the research question (including the use
of appropriate controls), and are the conclusions supported by the evidence
presented?
Yes
Are the methods sufficiently described to allow the study to be repeated?
Yes
Is the use of statistics and treatment of uncertainties appropriate?
Yes
Is the presentation of the work clear?
Yes
Are the images in this manuscript (including electrophoretic gels and blots) free
from apparent manipulation?
Yes
Reviewer’s report
Title: 
Clinical and endoscopic features of aorto-duodenal fistula resulting in its
definitive diagnosis: an observational study
Version: 
2 
Date: 
21 Dec 2020
Reviewer's report:
I want to thank the authors for the excellent revision they performed on their
paper, which is now much better organized and easy to read. 
I only suggest few minor changes:
- The first part of methods section is a little too much detailed (lines 57 to 61). I
suggest to modify the section as it follows: "The present study examined
patients' baseline clinical and laboratory data, past medical history, endoscopic
and CT scan findings, number of blood transfusions received, definitive
treatment and outcome. Type of scope used during endoscopy, the use of tip
attachments and of marking clips were also collected").
- The definition of shock provided (line 61) is not typical, is it the standard
definition you use in your institution? Usually, hemorrhagic shock is defined in
literature as the combination of systolic blood pressure < 100 mmHg and heart
rate > 100 beats per minute
- Line 66: the sentence "Even then, we did not find any abnormalities" should be
a hypothetical sentence: "If no abnormalities were found even using a tip
attachment, then we changed to pediatric colonoscope PCF-PQ260L…". 
- Specify if the described endoscopic strategy (lines 63-67) is the standard
strategy you follow in your institution for all suspected AUGIB or is specific for
patients with suspected bleeding from deep duodenum (such as patients with
history of aortic pathology)
- Line 68: reference is missing
- I suggest to put baseline characteristics of the patients (lines 104 to 113) at the
beginning of the result section
- Line 99: add the case number in brackets for the patient who died during
endoscopy
- When mentioning that all patients underwent aortic treatment in the past, report
also the mean timing of the intervention with the range (7 months to 13 years
prior). I think it is interesting that ADF could develop after so much different
periods of time (you could also briefly discuss it in the discussion)
- Line 140: reference is missing
- Discussion section should be a little enlarged and reorganized: I suggest to start
discussion with a short sentence about the importance of a prompt diagnosis in
ADF in order to increase chance of definitive treatment and survival; then
discuss the herald bleeding, that can mimic a "normal upper GI bleeding, and the
importance of patient's history of aortic or para-aortic treatments that should
increase the suspicion of ADF even for small, transient bleeding. Then discuss
the difficulty of definitive diagnosis and the frequent need for combined
radiology/endoscopy. 
- In the discussion, you should mention the missing information about timing of
endoscopy as a limitation of the present study. 
- Line 159: reference is missing
- I suggest to modify as follows the first sentence of conclusions: "In a patient
presenting with upper gastrointestinal bleeding, a history of intervention
involving the aorta should increase the suspicion of ADF. A combination of
endoscopy and CT scan is usually necessary to achieve a definitive diagnosis.
- Table 2: change commercial name "loxonin" to loxoprofen
Publons Reviewer Recognition
. Springer Nature can send verification of this
review directly to Publons (a subsidiary of Clarivate Analytics). If you would
like to take advantage of this service, please click on the “Yes” option below.
Your name, email address, title of the reviewed manuscript, name of the journal,
and date of your review submission (the “Review Data”) will then be transmitted
to Publons upon publication of the manuscript. If you have already registered at
Publons, they will notify you of the receipt of this review and update your profile
as per your settings and their policy. If you are not registered with Publons, you
will receive an email from them asking you to register in order for them to be
able to recognize your review on your new profile page. Publons may use the
Review Data to generate derivative metadata for the benefit of Publons and you
as a reviewer, carefully considering the sensitivity of such information. For
example, Publons may verify your record as a reviewer by updating your profile
published on its webservice if you have registered for such service or help
editors to identify candidate reviewers. Please find the details of processing in
Publons’ privacy policy 
https://publons.com/about/terms
Yes
Declaration of competing interests
Please complete a declaration of competing interests, considering the following
questions:
1
. 
Have you in the past five years received reimbursements, fees, funding, or
salary from an organisation that may in any way gain or lose financially
from the publication of this manuscript, either now or in the future?
2
. 
Do you hold any stocks or shares in an organisation that may in any way
gain or lose financially from the publication of this manuscript, either now
or in the future?
3
. 
Do you hold or are you currently applying for any patents relating to the
content of the manuscript?
4
. 
Have you received reimbursements, fees, funding, or salary from an
organization that holds or has applied for patents relating to the content of
the manuscript?
5
. 
Do you have any other financial competing interests?
6
. 
Do you have any non-financial competing interests in relation to this
paper?
If you can answer no to all of the above, write 'I declare that I have no competing
interests' below. If your reply is yes to any, please give details below.
I have no competing interests
Reviewer Publication Consent.
 I agree for my report to be made available
under an Open Access Creative Commons CC-BY License (
http://creativecommons.org/licenses/by/4.0
) if this manuscript is accepted for
publication. Any comments that I do not wish to be included in the published
report have been included as confidential comments to the editor, which will not
be published.
If you are not happy for us to publish this report, please contact the editorial
office before completing the review.
If you wish, you can include your name in your published report. Please note
you must decide whether to include your name at the start of the process and
confirm this decision whenever prompted. If you change your decision later, we
will not be able to publish your name.
I agree to the terms of the CC-BY 4.0 license; please 
do not
 publish my name
with my report. (default)
Is the study design appropriate to answer the research question (including the use
of appropriate controls), and are the conclusions supported by the evidence
presented?
Yes
Are the methods sufficiently described to allow the study to be repeated?
Yes
Is the use of statistics and treatment of uncertainties appropriate?
Yes
Is the presentation of the work clear?
Yes
Are the images in this manuscript (including electrophoretic gels and blots) free
from apparent manipulation?
Yes
Please review this paper.
user
Reviewer’s report
Title: 
Clinical and endoscopic features of aorto-duodenal fistula resulting in its
definitive diagnosis: an observational study
Version: 
2 
Date: 
21 Dec 2020
Reviewer's report:
I want to thank the authors for the excellent revision they performed on their
paper, which is now much better organized and easy to read. 
I only suggest few minor changes:
- The first part of methods section is a little too much detailed (lines 57 to 61). I
suggest to modify the section as it follows: "The present study examined
patients' baseline clinical and laboratory data, past medical history, endoscopic
and CT scan findings, number of blood transfusions received, definitive
treatment and outcome. Type of scope used during endoscopy, the use of tip
attachments and of marking clips were also collected").
- The definition of shock provided (line 61) is not typical, is it the standard
definition you use in your institution? Usually, hemorrhagic shock is defined in
literature as the combination of systolic blood pressure < 100 mmHg and heart
rate > 100 beats per minute
- Line 66: the sentence "Even then, we did not find any abnormalities" should be
a hypothetical sentence: "If no abnormalities were found even using a tip
attachment, then we changed to pediatric colonoscope PCF-PQ260L…". 
- Specify if the described endoscopic strategy (lines 63-67) is the standard
strategy you follow in your institution for all suspected AUGIB or is specific for
patients with suspected bleeding from deep duodenum (such as patients with
history of aortic pathology)
- Line 68: reference is missing
- I suggest to put baseline characteristics of the patients (lines 104 to 113) at the
beginning of the result section
- Line 99: add the case number in brackets for the patient who died during
endoscopy
- When mentioning that all patients underwent aortic treatment in the past, report
also the mean timing of the intervention with the range (7 months to 13 years
prior). I think it is interesting that ADF could develop after so much different
periods of time (you could also briefly discuss it in the discussion)
- Line 140: reference is missing
- Discussion section should be a little enlarged and reorganized: I suggest to start
discussion with a short sentence about the importance of a prompt diagnosis in
ADF in order to increase chance of definitive treatment and survival; then
discuss the herald bleeding, that can mimic a "normal upper GI bleeding, and the
importance of patient's history of aortic or para-aortic treatments that should
increase the suspicion of ADF even for small, transient bleeding. Then discuss
the difficulty of definitive diagnosis and the frequent need for combined
radiology/endoscopy. 
- In the discussion, you should mention the missing information about timing of
endoscopy as a limitation of the present study. 
- Line 159: reference is missing
- I suggest to modify as follows the first sentence of conclusions: "In a patient
presenting with upper gastrointestinal bleeding, a history of intervention
involving the aorta should increase the suspicion of ADF. A combination of
endoscopy and CT scan is usually necessary to achieve a definitive diagnosis.
- Table 2: change commercial name "loxonin" to loxoprofen
Publons Reviewer Recognition
. Springer Nature can send verification of this
review directly to Publons (a subsidiary of Clarivate Analytics). If you would
like to take advantage of this service, please click on the “Yes” option below.
Your name, email address, title of the reviewed manuscript, name of the journal,
and date of your review submission (the “Review Data”) will then be transmitted
to Publons upon publication of the manuscript. If you have already registered at
Publons, they will notify you of the receipt of this review and update your profile
as per your settings and their policy. If you are not registered with Publons, you
will receive an email from them asking you to register in order for them to be
able to recognize your review on your new profile page. Publons may use the
Review Data to generate derivative metadata for the benefit of Publons and you
as a reviewer, carefully considering the sensitivity of such information. For
example, Publons may verify your record as a reviewer by updating your profile
published on its webservice if you have registered for such service or help
editors to identify candidate reviewers. Please find the details of processing in
Publons’ privacy policy 
https://publons.com/about/terms
Yes
Declaration of competing interests
Please complete a declaration of competing interests, considering the following
questions:
1
. 
Have you in the past five years received reimbursements, fees, funding, or
salary from an organisation that may in any way gain or lose financially
from the publication of this manuscript, either now or in the future?
2
. 
Do you hold any stocks or shares in an organisation that may in any way
gain or lose financially from the publication of this manuscript, either now
or in the future?
3
. 
Do you hold or are you currently applying for any patents relating to the
content of the manuscript?
4
. 
Have you received reimbursements, fees, funding, or salary from an
organization that holds or has applied for patents relating to the content of
the manuscript?
5
. 
Do you have any other financial competing interests?
6
. 
Do you have any non-financial competing interests in relation to this
paper?
If you can answer no to all of the above, write 'I declare that I have no competing
interests' below. If your reply is yes to any, please give details below.
I have no competing interests
Reviewer Publication Consent.
 I agree for my report to be made available
under an Open Access Creative Commons CC-BY License (
http://creativecommons.org/licenses/by/4.0
) if this manuscript is accepted for
publication. Any comments that I do not wish to be included in the published
report have been included as confidential comments to the editor, which will not
be published.
If you are not happy for us to publish this report, please contact the editorial
office before completing the review.
If you wish, you can include your name in your published report. Please note
you must decide whether to include your name at the start of the process and
confirm this decision whenever prompted. If you change your decision later, we
will not be able to publish your name.
I agree to the terms of the CC-BY 4.0 license; please 
do not
 publish my name
with my report. (default)
Is the study design appropriate to answer the research question (including the use
of appropriate controls), and are the conclusions supported by the evidence
presented?
Yes
Are the methods sufficiently described to allow the study to be repeated?
Yes
Is the use of statistics and treatment of uncertainties appropriate?
Yes
Is the presentation of the work clear?
Yes
Are the images in this manuscript (including electrophoretic gels and blots) free
from apparent manipulation?
Yes
assistant