Association between Vascular Calcification and Esophagojejunal Anastomotic Complications after Total Gastrectomy for Gastric Cancer: A Propensity-Matched Study
Round 1
Reviewer 1 Report
Association between Vascular Calcification and Esophagojejunal Anastomotic Complications after Total Gastrectomy for Gastric Cancer? A Propensity-Matched Study
Abstract
Esophagojejunal anastomosis (EJA) complications after total gastrectomy are related to significant morbidity and mortality. The aim of this study was to evaluate the association between arterial calcifications and EJA complications such as leak and stricture for gastric cancer. Between January 2014 and October 2019, 30 patients with EJA complications after total gastrectomy were enrolled and matched to 30 patients without complications. Arterial calcification grade on preoperative computed tomography (CT) was reported in the abdominal aorta and superior mesenteric artery (SMA) as “absent”, “minor”, or “major”, and in the jejunal vascular arcade (JVA) and left inferior phrenic artery (LIPA) as “absent” or “present”. Chi-square test was used to compare the variables between the two groups. p-Value < 0.050 was considered statistically significant. Among 30 patients, the numbers of patients with leak and stricture were 23 and 7, respectively. Aortic calcifications were not associated with EJA complications regardless of their grade (p = 0.440). Only major SMA calcifications were associated with EJA complications, as they were present in 5 patients (16.7%) in the complication group and absent in the non-complication group (p = 0.020). Major SMA calcifications were more related to anastomotic stricture than leak. Three (13.0%) out of 23 patients with leak and 2 (28.6%) out of 7 with stricture had major SMA calcifications (p = 0.028). No calcifications were detected in the JVA or LIPA in any of the 60 patients. Major SMA calcifications were found to be associated with EJA complications, especially in stricture.
Comment: pls state the study design: is it a prospective trial or retrospective data review ? If it is a prospective study, the CONSORT checklist should be used as a guide too.
- Introduction
In this study, we attempted to find if an association exists between vascular 53 calcifications and the incidence of EJA complications after total gastrectomy for gastric 54 cancer using preoperative computed tomography (CT) assessment of the location and 55 extent of calcifications.
Comment:
- Materials and Methods
2.1. Definitions of complications
2.2. Patients & Matching
2.3. Anastomosis Technique
2.4. Image Acquisition and Evaluation
Comment : If this is prospective clinical trial, please also consider to report the following sections:
Title and abstract
1a
Identification as a randomised trial in the title
1b
Structured summary of trial design, methods, results, and conclusions (for specific guidance see CONSORT for abstracts21 31)
Introduction
Background and objectives
2a
Scientific background and explanation of rationale
2b
Specific objectives or hypotheses
Methods
Trial design
3a
Description of trial design (such as parallel, factorial) including allocation ratio
3b
Important changes to methods after trial commencement (such as eligibility criteria), with reasons
Participants
4a
Eligibility criteria for participants
4b
Settings and locations where the data were collected
Interventions
5
The interventions for each group with sufficient details to allow replication, including how and when they were actually administered
Outcomes
6a
Completely defined pre-specified primary and secondary outcome measures, including how and when they were assessed
6b
Any changes to trial outcomes after the trial commenced, with reasons
Sample size
7a
How sample size was determined
7b
When applicable, explanation of any interim analyses and stopping guidelines
Randomisation:
Sequence generation
8a
Method used to generate the random allocation sequence
8b
Type of randomisation; details of any restriction (such as blocking and block size)
Allocation concealment mechanism
9
Mechanism used to implement the random allocation sequence (such as sequentially numbered containers), describing any steps taken to conceal the sequence until interventions were assigned
Implementation
10
Who generated the random allocation sequence, who enrolled participants, and who assigned participants to interventions
Blinding
11a
If done, who was blinded after assignment to interventions (for example, participants, care providers, those assessing outcomes) and how
11b
If relevant, description of the similarity of interventions
Statistical methods
12a
Statistical methods used to compare groups for primary and secondary outcomes
12b
Methods for additional analyses, such as subgroup analyses and adjusted analyses
Results
Participant flow (a diagram is strongly recommended)
13a
For each group, the numbers of participants who were randomly assigned, received intended treatment, and were analysed for the primary outcome
13b
For each group, losses and exclusions after randomisation, together with reasons
Recruitment
14a
Dates defining the periods of recruitment and follow-up
14b
Why the trial ended or was stopped
Baseline data
15
A table showing baseline demographic and clinical characteristics for each group
Numbers analysed
16
For each group, number of participants (denominator) included in each analysis and whether the analysis was by original assigned groups
Outcomes and estimation
17a
For each primary and secondary outcome, results for each group, and the estimated effect size and its precision (such as 95% confidence interval)
17b
For binary outcomes, presentation of both absolute and relative effect sizes is recommended
Ancillary analyses
18
Results of any other analyses performed, including subgroup analyses and adjusted analyses, distinguishing pre-specified from exploratory
Harms
19
All important harms or unintended effects in each group (for specific guidance see CONSORT for harms28)
Discussion
Limitations
20
Trial limitations, addressing sources of potential bias, imprecision, and, if relevant, multiplicity of analyses
Generalisability
21
Generalisability (external validity, applicability) of the trial findings
Interpretation
22
Interpretation consistent with results, balancing benefits and harms, and considering other relevant evidence
Other information
Registration
23
Registration number and name of trial registry
Protocol
24
Where the full trial protocol can be accessed, if available
Funding
25
Sources of funding and other support (such as supply of drugs), role of funders
2.5. Statistical analysis
The author has correctly selected chi square test for association (also called the chi-square test for independence) which is used to find a relationship between two categorical variables.
Other comments
Table 1. Modified visual arterial calcification grading system
Table 2. Comparison of baseline characteristics between complication and non-complication groups after propensity score matching
Table 3. Association between arterial calcifications with esophagojejunal anastomosis complications
Table 4. The correlation between the kinds of anastomotic complication and the degree of SMA calcification
Table 1-4 are easy to read and well presented
The limitation of this study lies in the small sample size due to the relatively low 255 incidence of EJA complications. However, it was possible to conclude that major SMA 256 calcifications might induce tissue ischemia that compromises esophagojejunal 257 anastomotic healing after total gastrectomy for gastric cancer, and lead to anastomotic 258 complications, particularly stricture, rather than leak
Comment: to include Sample Size calculation
Conclusions
In conclusion, vascular calcification could affect for esophagojejunostomy condition 261 after total gastrectomy. Preoperative CT scan could predict patients at risk. Further 262 studies are needed to evaluate advanced techniques such as intraoperative ICG 263 angiography in preventing EJA complications in patients with major SMA calcifications
Comment: the conclusion should be expanded to include further summary
Author Response
Abstract
Comment: pls state the study design: is it a prospective trial or retrospective data review ? If it is a prospective study, the CONSORT checklist should be used as a guide too.
Thank you for comment. Our study is retrospective review. We added the study design in abstract.
--> Between January 2014 and October 2019, 30 patients with EJA complications after total gastrectomy were enrolled and matched to 30 patients without complications through retrospective data review.
- Materials and Methods
Comment : If this is prospective clinical trial, please also consider to report the following sections:
Our study is retrospective study. Thank you for your consideration.
2.5. Statistical analysis
Comment : The author has correctly selected chi square test for association (also called the chi-square test for independence) which is used to find a relationship between two categorical variables.
Thank you for your comment.
Other comments
Table 1-4 are easy to read and well presented
Thank you for your comment.
Comment: to include Sample Size calculation
Our study is retrospective study using data review. Therefore, sample size calculation was not conducted. Thank you for your comment.
Comment: the conclusion should be expanded to include further summary
We added further summary in conclusion.
--> In conclusion, vascular calcification could affect for esophagojejunostomy condition after total gastrectomy. Especially, major SMA calcification is associated with stricture of EJA. Preoperative CT scan could predict patients at risk. Further studies are needed to evaluate advanced techniques such as intraoperative ICG angiography in preventing EJA complications in patients with major SMA calcifications.
Reviewer 2 Report
Leak and strictures of the anastomosis are the most severe complications after total gastectomy in patients with gastric cancer. Recently, indications for detailed operations have been significantly expanded, including elderly patients who have severe comorbid pathology and vascular disorders. From these positions, of great interest is the analysis of the effect of vascular patency disorders on the frequency of postoperative complications in the area of ​​the esophago-intestinal anastomosis. The article is of interest to practical surgeons. I believe this study is relevant.
The results of this study can be used as additional factors for determining the risk of postoperative complications and for selecting patients with gastric cancer for surgical treatment.
The study is not randomized and is retrospective. The authors carried out a qualitative and comprehensive analysis of the literature on this issue. To my mind, the article is very interesting. I see no need for additional changes.
The conclusion logically ends the article. The authors showed that major SMA calcifications were associated with EJA complications in 16.7% of cases. References in the text of the article fully correspond to the article list of references, both in the order of citation and in content. The authors used contemporary literature.
Author Response
Thank you for insightful comments.
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
