Review for 10.1186/s12876-022-02273-2 (2022)

Title: External validation of the BEST-J score and a new risk prediction model for ESD delayed
bleeding in patients with early gastric cancer
Version: 2 Date: 13 Feb 2022
Reviewer's report:
The authors conducted a single center retrospective study in which the aim was to evaluate the
risk factors for delayed bleeding after gastric ESD of early gastric cancer and to propose a risk
prediction model. This is an important question to answer. I would like to raise some points to
improve this manuscript.
Comments 1.
There is no patient with CKD with hemodialysis and a few patients taking warfarin or DOAC.
These factors are the most important in BEST-J score. The rate of delayed bleeding of patients
with anticoagulants was extremely high at 33% (1/3), which did not reach a significant
difference. As you described this point in discussion, I think this makes a big difference between
this study and the study of BEST-J score. I think it is necessary to describe these factors rather
than vaguely describing them as serious complications or severe comorbidities.
Comments 2.
Did you use hemoclips when hemostasis cannot be achieved by using hemostatic forceps? I
think in most cases intraoperative bleedings are managed by hemostatic forceps and rarely need
hemostasis by using hemoclips. You should clarify the situation when intraoperative use of
hemoclips was selected and show the number of hemoclips.
Azumi et al. reported clipping after gastric ESD prevented delayed bleeding [Gastric Cancer
2019 22:567-575]. Differences or similarities with this report should be clarified. Could you
discuss the point that the more patients we use hemoclips in addition to applying prophylactic
coagulation, the lower the bleeding rate can be?
This is an important point in reducing the rate of delayed bleeding.
Comments 3.
You displayed PT and APTT were obtained 1-2days before ESD. Are there patients with the
prolongation of APTT associated with heparin bridging therapy (HBT)? Many reports have
shown HBT made a high delayed bleeding rate in endoscopic resection. You should also describe
the number of patients with HBT and how many patients suffered delayed bleeding in patients
with HBT.
Whether the patients with APTT prolongation have ever had symptoms such as trouble stopping
bleeding or have diseases in which APTT prolongs such as hemophilia and von Willebrand
disease? My concern is whether these patients can be picked up by other than blood test.
You should display the measuring kit of APTT you used if you don’t show normal APTT levels.
Comments 4.
In this study, the lower part of tumor location shared a large part and the average age is lower
than that in the report of BEST-J score. I think gastric atrophy is also different from that in
the report of BEST-J score. Please show the data of gastric atrophy and analyze the association
between the rate of delayed bleeding and gastric atrophy.
Comment 5.
Some previous reports revealed combined use of anticoagulant therapy showed a high delayed
bleeding rate in endoscopic resection. You should show the bleeding rate in patients with a
combined use of 2 or more anticoagulant therapy.
Comment 6.
You should describe the company name of each clip and also describe the ESD devices.
Comment 7.
You chose tumor size >20mm as the factor for postoperative bleeding. Did you decide to use
this size by ROC analysis?
Comment 8.
You described “the tumor condition was poor, which increased the difficulty of the ESD
operation. This also contributed to the higher delayed bleeding rate in the EGC patients in our
study” (P.13, lines 21-).
You should clarify specifically which condition made the higher bleeding rate in this study.
Comment 9.
You should clarify by which guideline the "classification" and “absolute indication” were
defined in table2.
What is the difference between curative resection and absolute indication?
You should also show the data of ulceration.
Comment 10.
Please correct “>60 mm” in procedure duration to “>60 min” in table 2.