Review for 10.1186/s12876-024-03291-y (2024)

Title: Dilated Common Bile Duct is Commonly Associated with Main Duct Intraductal
Papillary Mucinous Neoplasm of the Pancreas
Version: 0 Date: 20 Mar 2024
Reviewer's report:
Major Issues
Insufficient Consideration of the Causes of Common Bile Duct (CBD) Dilatation
While the paper speculates on the association with biliary lesions, the mechanism of CBD
dilatation seen in MD-IPMN, such as compression by the dilated main pancreatic duct, needs
further exploration and consideration of other possible factors.
Minor Issues
1. Lack of Explanation for Narrowing Down Study Subjects
The process of narrowing down from 2400 cases to 158 cases requires detailed explanation.
Criteria for selection, including the number of attempts at FNA and the number of successful
fluid collections, should be clearly defined.
2. Lack of Explanation on the Classification Method Based on EUS and Cyst Fluid
Characteristics
The paper should clarify how the two criteria were combined, especially the classification
criteria for cases where the CEA value is given or the communication with the main pancreatic
duct is not observed.
3. Inconsistency in the Definition of CBD Dilatation
The paper contradicts itself by referencing a normal CBD diameter of up to 7.6mm in the elderly,
while defining dilatation as more than 6mm in the study, regardless of age. A statistical analysis
considering age as a continuous variable is needed.
4. Issues with the Handling of SCN and MCN
While only adenomas are considered for SCN, there is no distinction between adenomas and
adenocarcinomas in MCN. The number of lesions in these categories should be clarified.
5. Lack of Consistency in Abbreviations (page 1, lines8-9, page2,line 22)
The definition of IPMN-P lacks consistency, leading to confusion. Clear definitions and uniform
terminology are required.
6. Lack of Explanation for Differences in P-values (Page 7, line 24 and page 8, line 4)
The document does not sufficiently explain the differences in P-values mentioned. A clear
statistical interpretation is necessary.
7. Need for More Detailed Tables (Table 1)
IPMN patients should be divided into MD-IPMN, BD-IPMN, M-IPMN categories, and Group
B into MCN, SCN, PC. Additionally, the values of CEA and amylase in the cyst fluid should
be aggregated.
8. Lack of Explanation on Statistical Analysis Methods (Table 2 and 3)
The paper lacks detailed explanations of the statistical analysis methods used, including multiple
testing and the types of tests conducted. Accurate description of statistical methods and the
selection of appropriate testing methods are required.
Table 2 compares the frequency of common bile duct dilatation in M-IPMN, BD-IPMN, M-
IPMN, and Group B. Multiple testing should not be performed when comparing three or more
groups. First, it is necessary to perform an overall test and then perform a multiple comparison
test such as a post-hoc test. In doing so, please clearly state the proportion of common bile duct
dilatation in each group.
Please specify the type of test for each item in Table 3. For items other than Age, please clearly
indicate the percentage of common bile duct dilatation for each item.
9. Details on Multiple Linear Regression Analysis (Table 4)
The paper should elaborate on the multiple linear regression analysis, specifying which variables
were used as independent and dependent variables.