Complete Mesogastric Excisions Involving Anatomically Based Concepts and Embryological-Based Surgeries: Current Knowledge and Future Challenges
Round 1
Reviewer 1 Report
Girnyi et al. reviewed the concept of "complete mesogastric excisions" and its application in gastric cancer surgery. The review is interesting and will add to our knowleage of this concept. However, I have following suggestions to improve this manuscript:
1. The introduction should be rewritten. The introduction is suggested to introduce the current status of related concepts on surgeries for gastric malignancies, including en-bloc excision, and systematic mesogastric excision/CME, discussing the differences between them. Listing the shortcomings of en-bloc excision if any, and then introduce the CME.
2. What is the metastasis V route? As I known, it's just a hypothesis, which has not yet been proved to date. I did not agree with the opinions proposed in the introdution that "isolated tumour cells and small tumour nodules situated in the mesogastrium in adipose connective tissue have no direct link to the primary tumour nor to lymphatic or vascular vessels' and "this pathway differs from the other four classical metastatic pathways and cannot be removed by standard D2 gastrectomy". How could they prove that those isolated tumour cells and small tumour nodules not migrating from lymphatic and vascular vessels, or from directly seeding from primary tumor? Moreover, en-bloc excision can remove them. Acctually, CME did not and should not based on this hypothesis. The authors should emphasize this debate.
Minor point:
1. In the introduction, the sentence "Rohatgi et al. have shown that despite radical surgical treatment, disease recession is observed in approximately 60% of patients'. What does "disease recession" mean? Rohatgi et al. showed that tumor reccurrence is observed in approximately 68% of patients.
Author Response
Reviewer #1:
Q1: The introduction should be rewritten. The introduction is suggested to introduce the current status of related concepts on surgeries for gastric malignancies, including en-bloc excision, and systematic mesogastric excision/CME, discussing the differences between them. Listing the shortcomings of en-bloc excision if any, and then introduce the CME.
Response to Reviewer comment No. 1
Thank You for Your kind words as well as some critics. Indeed, we changed the order of introduction for better explanation of the idea of mesogastrium and we added some important points mentioned by the reviewer.
The en-block excision is explained afterwards the CME shorlty after ethe introduciotn of gastric cancer information in general:
We changed the order and added in the text:
The primary aim of gastrointestinal cancer surgery is an en block resection of the tumour together with its complex lymphovascular drainage that follows an organ’s specific mesenteric layers [9]. The concept of an en block resection of the untouched fascia covering the mesenteric tissue mimicking an envelope is the basis for complete meso-excisions. Heald et al. proposed a revolution in rectal surgery by implementing a total mesorectal excision [10]. This procedure involves a sharp dissection following embryological planes with intact mesorectal fascia that covers not only the tumour but also lymphatic vessels and regional lymph nodes. Following this idea, the local recurrence rate in conventional surgery, which was as high as 33%, dropped after the implementation of TME to 10% [11]. A similar idea was proposed by Hochenberger et al. for colon cancer [12]. A complete mesocolic excision with a dissection of the mesocolic planes together with vascular ligation led to an improved short survival rate in a German group and in a Danish population-based study [13]. The idea of applying mesentery-based surgeries became popular in a number of other organs and was subsequently proposed. A meso-oesophageal resection of the thoracic oesophagus was proposed by Matsubara et al., while Cuesta et al. presented a minimally invasive meso-oesophageal model [14], [15].
The idea of the mesopancreas was presented by Adham et al. and a recent study presented robotic mesopancreatic resections on 289 patients [16]. In all, with an increasing number of centres implementing this idea together with clinical data into daily practices, this technique has already shown a huge potential in this area [16], [17].
The idea of meso-excision was also proposed in gastric cancer resections.
Q2. What is the metastasis V route? As I known, it's just a hypothesis, which has not yet been proved to date. I did not agree with the opinions proposed in the introdution that "isolated tumour cells and small tumour nodules situated in the mesogastrium in adipose connective tissue have no direct link to the primary tumour nor to lymphatic or vascular vessels' and "this pathway differs from the other four classical metastatic pathways and cannot be removed by standard D2 gastrectomy". How could they prove that those isolated tumour cells and small tumour nodules not migrating from lymphatic and vascular vessels, or from directly seeding from primary tumor? Moreover, en-bloc excision can remove them. Acctually, CME did not and should not based on this hypothesis. The authors should emphasize this debate.
Response to Reviewer comment No. 2
We know that this a crucial information and indeed one of the fundamental ones. However, we also know that it is still just a hypothesis that need to be proven by further research on many levels.
We added:
This hypothesis needs further evidence as a new concept require to be well established with preclinical as well as clinical studies
We need to point here that as with every new hypothesis we need more evidence and detailed technical aspects of operation followed by CME principles to show that en-block resection might be not enough in terms of oncological outcome. The primary and preliminary aspects of this new technique are presented and discussed.
We also added a figure that explains a table model and a Table 1 that explains scoring the mesogastrium that also helps in explain abovementioned issues.
Figure 1. Table model for complete mesogastric excision.
Q3. In the introduction, the sentence "Rohatgi et al. have shown that despite radical surgical treatment, disease recession is observed in approximately 60% of patients'. What does "disease recession" mean? Rohatgi et al. showed that tumor reccurrence is observed in approximately 68% of patients.
Response to Reviewer comment No. 3
Sorry for this mistake. We fixed that.
We added:
Rohatgi et al. have shown that despite radical surgical treatment, disease recurrence is observed in approximately 60% of patients [6].
On behalf of all the Authors, we thank the Editor and Reviewers for their important comments and useful suggestions to improve our paper.
Author Response File: 
Author Response.docx
Reviewer 2 Report
- What is the main question addressed by the research?
The existing surgical technologies in the treatment of patients with gastric cancer have reached the highest level and do not have significant prospects for improving immediate and long-term results. However, the techniques based on the concept of "embryonic" surgery, namely TME and CME, for rectal and colon cancer surgeries have allowed the reduction in the frequency of local recurrence.
The feasibility of using mesogastric excisions in surgical treatment of gastric cancer is of great interest. The technique of mesogastric excisions is likely can reduce the risk of intraoperative dissemination of cancer cells.
- Do you consider the topic original or relevant in the field, and if so, why?
Given the answer to the first question, I believe this study is relevant.
- What does it add to the subject area compared with other published material?
The authors systematized the literature data on the problem of mesogastric excisions. The issues of embryogenesis, which create the preconditions for performing mesogastric excisions, the technical aspects of this surgical technique and the results of the routine use of TME and CME, on the basis of which the transition to the practical application of mesogastric excisions is made, are discussed. The results and technical aspects of mesogastric excisions under conditions of open and laparoscopic surgery are assessed.
- What specific improvements could the authors consider regarding the methodology?
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.
- Are the conclusions consistent with the evidence and arguments presented and do they address the main question posed?
The conclusion logically ends the article. It is substantiated by the presented data and answers the main research question - the relevance of studying the effectiveness of mesogastric excisions as a new technique in the surgical treatment of gastric cancer.
- Are the references appropriate?
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.
- Please include any additional comments on the tables and figures.
The article does not contain tables or figures.
Author Response
We thank the Reviewer for important comments and useful suggestions to improve our paper.
We added Table and figure.
Reviewer 3 Report
Dear Authors,
Your manuscript provides very crucial information and seems to be important in the field of surgical oncology. My only suggestion for you is to provide a summarative table that will provide all the crucial conclusions from the text so it would be easier for readers.
Author Response
We thank the Reviewer for important comments and useful suggestions to improve our paper. Accordingly, we added a table that will provide all the crucial conclusions
Round 2
Reviewer 1 Report
The comments are appropriately answered.
