Review for 10.1186/s12876-024-03241-8 (2024)

Title: Outcome of patients with perihilar cholangiocarcinoma and previous biliary
instrumentation: An observational study
Version: 2 Date: 27 Dec 2023
Reviewer:  Jian Zhao
Reviewer's report:
This study attempted to compare the complications and survival of patients with and without
trans-papillary biliary drainage, but there may be inherent selection bias between these two
groups, as patients who do not consider trans-papillary biliary drainage in clinical practice tend
to have milder conditions, so it is normal for them to not develop cholangitis and have a longer
survival. The purpose of preoperative biliary drainage for hilar cholangiocarcinoma is to restore
liver function and reduce the risk of postoperative liver failure. Therefore, this study suggests not
to undergo trans-papillary biliary drainage treatment directly due to the possibility of cholangitis,
which is clinically unacceptable. In addition, there are some other issues in this study listed
below:
major issues#
1. What are the indications for biliary drainage in your research? Is there a unified standard?
2. Patients who need to undergo biliary drainage may have a more severe condition. Please
compare in detail the basic information, such as T stage, N stage, and the treatment received, etc.
Introduction part
3. Too few references cited.
4. The current challenges faced by hilar cholangiocarcinoma are not explained enough, in
other words, the logical thinking behind why you are conducting this research needs to be
reconsidered.
Methods part
5. Some values do not match, for example, 129-92=36?
6. Some numerical values need to be written, such as how to determine bilirubin retained elevated
7. There seems to be no logical correlation between the factors you listed and the treatment
received within 30 days.
8. Why did you choose 30 days as the cutoff value#
Results part
9. Please provide the P-value in Table 2.
10. The P-values for the multivariate analysis also need to be provided.
11. The P-values for survival analysis need to be listed in Figure 1.
12. The P-value in Figure 3 was obtained by comparing between which two groups?
13. Many factors can affect the survival of patients, such as whether to undergo surgical resection
or not. Is the surgical margin positive? Is adjuvant therapy performed after surgery? Was the
treatment plan the same? So it is not appropriate to compare the impact of TPBD on survival
directly. These factors should be taken into consideration.
Discussion part
14. The discussion content is not concise enough, and many irrelevant content needs to be
deleted.
15. Discussion around the main findings of this study is lacking.
16. The content of the conclusion is too long, and some conclusions are not related to the content
of this study, such as how you get percutaneous stent placement is better than endoscopic stent
placement.
Minor issues#
“The primary outcome studied was timely treatment, defined as receiving either surgery,
chemotherapy, radiation, or portal vein embolization in preparation for surgery within 30 days
of evaluation; overall survival (OS) from time of presentation was estimated.” should be placed
in the Materials and Methods section.
Other suggestions:
1. In the implementation of bile duct drainage through ERCP, as pancreatitis is a disease
that is relatively easy to induce and may cause serious consequences, do your patients have
pancreatitis?
2. There are differences in the occurrence of cholangitis between the placement of the lower edge
of the stent inside the bile duct and crossing the duodenal papilla. It may be more interesting to
analyze the significance of this different placement method.