Modified Bikini Line Sleeve Gastrectomy (MBLSG): Defining Surgical Landmarks and Clinical Outcomes in a Large-Scale Cohort of 906 Patients

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you for the opportunity to review the manuscript entitled “Modified Bikini Line Sleeve Gastrectomy (MBLSG): Defining Surgical Landmarks and Clinical Outcomes in a Large-Scale Cohort of 906 Patients.” Below, I present my comments:

1. I suggest that abbreviations be defined in the main body of the manuscript and avoided in the abstract. The main text also requires revision due to repeated expansion of the same abbreviations.
2. The manuscript lacks a control group, which the authors acknowledge. Therefore, I recommend avoiding statements suggesting the superiority of MBLSG over LSG in terms of cosmetic outcomes and removing such claims from the conclusions, as they are not supported by the presented data.
3. What scale was used to assess cosmetic satisfaction? Please provide this information, including whether the scale was validated.
4. Some patients required blood transfusions; please clarify the underlying reasons. Were these cases associated with reoperation? Were the bleeding events clinically overt? Did they occur intraoperatively or postoperatively? What was the source of bleeding (intraluminal vs intra-abdominal)?
5. Were any patients initially qualified for MBLSG converted intraoperatively to a conventional LSG? If so, please provide the frequency and reasons for such conversions.

The manuscript requires minor revisions, after which I would recommend it for publication.

Author Response

Reviewer 1, Comment 1:

I suggest that abbreviations be defined in the main body of the manuscript and avoided in the abstract. The main text also requires revision due to repeated expansion of the same abbreviations.

Our response to Reviewer 1 Comment 1: Thank you for bringing this formatting issue to our attention. We entirely agree with your suggestion. We have revised the abstract to remove unnecessary abbreviations, utilizing the full terms instead (e.g., laparoscopic sleeve gastrectomy, total body weight loss, excess weight loss). Furthermore, we have meticulously reviewed the entire main manuscript. All abbreviations (such as LSG, BLSG, and MBLSG) are now strictly defined only at their first appearance in the text. We have removed all subsequent redundant expansions throughout the manuscript, particularly within the Discussion section, ensuring that only the abbreviations are used there after.

Reviewer 1, Comment 2:

The manuscript lacks a control group, which the authors acknowledge. Therefore, I recommend avoiding statements suggesting the superiority of MBLSG over LSG in terms of cosmetic outcomes and removing such claims from the conclusions, as they are not supported by the presented data.

Our response to Reviewer 1 Comment 2: We sincerely thank the reviewer for pointing out this critical methodological distinction. We completely agree that without a direct control group (conventional LSG), asserting "superiority" is not supported by the current study design. We have thoroughly revised the manuscript to correct this. Specifically, in the Abstract, Discussion, and Conclusions sections, we have removed the word "superior" and all claims of superiority. Instead, we have rephrased these sentences to accurately reflect our findings, stating that the MBLSG technique "yields high patient-reported cosmetic satisfaction" and "demonstrates favorable aesthetic outcomes." The hypothesis of statistical superiority will be the primary focus of our subsequent comparative analysis, as noted in the Methods section.

Reviewer 1, Comment 3:

What scale was used to assess cosmetic satisfaction? Please provide this information, including whether the scale was validated.

Our response to Reviewer 1 Comment 3: We appreciate the reviewer’s insightful question regarding the assessment of cosmetic satisfaction. In our institution’s routine follow-up protocol, cosmetic satisfaction is evaluated using a simple, non-validated 5-point Likert scale (1 = completely dissatisfied, 5 = completely satisfied) specifically querying the patient's satisfaction with the surgical scars. We acknowledge that the lack of a formally validated psychometric or cosmetic evaluation tool is a limitation of our retrospective design. We have now explicitly detailed this scale in the Materials and Methods section and added the use of a non-validated scale as a limitation in the Discussion section.

Reviewer 1, Comment 4:

Some patients required blood transfusions; please clarify the underlying reasons. Were these cases associated with reoperation? Were the bleeding events clinically overt? Did they occur intraoperatively or postoperatively? What was the source of bleeding (intraluminal vs intra-abdominal)?

Our response to Reviewer 1 Comment 4: We thank the reviewer for highlighting this important aspect of our complication profile. Among our cohort, 7 patients (0.8%) required blood transfusions. All of these bleeding events occurred postoperatively. Clinically, these events were overt, presenting with a significant drop in hemoglobin levels accompanied by tachycardia. Importantly, none of these patients required reoperation; all cases were successfully managed conservatively with close hemodynamic monitoring and blood transfusions. Because re-laparoscopy was not clinically indicated, the exact source of the bleeding (intraluminal versus intra-abdominal) could not be definitively visualized; however, the self-limiting clinical course was highly consistent with minor staple-line bleeding. We have now incorporated these clinical details into the Results section to provide a fully transparent safety profile.

Reviewer 1, Comment 5: Were any patients initially qualified for MBLSG converted intraoperatively to a conventional LSG? If so, please provide the frequency and reasons for such conversions.

The manuscript requires minor revisions, after which I would recommend it for publication.

Our response to Reviewer 1 Comment 5: We appreciate the reviewer raising this practical point. In our cohort of 906 patients, there were no intraoperative conversions from the MBLSG technique to conventional LSG. We attribute this 100% completion rate to our rigorous preoperative patient selection criteria. By strictly adhering to the anatomical thresholds (e.g., xiphoid-umbilical distance <24 cm) and carefully excluding patients with contraindications such as a sagging panniculus, large hiatal hernias, or suspected severe intra-abdominal adhesions, we ensured that all intended MBLSG procedures could be successfully completed as planned. We have added a statement to the Results section to clarify this point.

Reviewer 2 Report

Comments and Suggestions for Authors

Recommendation: Major Revision

General Comments

This manuscript describes a modified version of the bikini-line sleeve gastrectomy (MBLSG) and reports the authors’ experience in a remarkably large cohort of 906 patients. The topic is clinically relevant, as aesthetic outcomes have become increasingly important in bariatric surgery, particularly among younger and predominantly female patient populations. The authors should be commended for presenting a detailed technical description of the procedure and for attempting to establish practical anatomical selection criteria that may facilitate reproducibility.

The principal strength of the study is the large number of included patients, which exceeds previously published series on bikini-line sleeve gastrectomy. The manuscript is generally well organized and the surgical technique is described in considerable detail.

However, several important methodological and interpretative issues limit the scientific impact of the study in its current form. Most notably, the absence of a control group prevents any meaningful conclusions regarding superiority, safety advantages, or cosmetic benefits compared with conventional laparoscopic sleeve gastrectomy. Furthermore, key methodological details regarding outcome assessment, follow-up, complication reporting, and patient selection require clarification.

For these reasons, I believe the manuscript would benefit from substantial revision before it can be considered for publication.

Major Comments

1. Lack of a comparator group

The most important limitation of this study is the absence of a control cohort undergoing conventional laparoscopic sleeve gastrectomy. Throughout the manuscript, the authors repeatedly suggest that MBLSG provides superior cosmetic outcomes and favorable clinical performance. However, without a direct comparison, these statements cannot be adequately supported.

The current study successfully demonstrates feasibility and provides a large descriptive experience, but it does not establish superiority or equivalence relative to standard techniques. The conclusions should therefore be revised accordingly and the language should be more cautious throughout the manuscript.

2. Cosmetic outcomes require better methodological definition

The central rationale for introducing MBLSG is improved aesthetics. Nevertheless, cosmetic outcomes are represented only by a postoperative cosmetic score of 4 ± 0.8.

The authors should clearly explain:

• How cosmetic satisfaction was assessed.
• Whether the score was patient-reported or investigator-assessed.
• At what postoperative time point the evaluation was performed.
• Whether a validated cosmetic assessment tool was used.
• Whether scar photographs were systematically evaluated.

Without this information, it is difficult to interpret one of the manuscript’s most important outcome measures.

3. Incomplete reporting of follow-up

Weight-loss outcomes are reported at 12 months, but the manuscript does not specify:

• How many patients completed 12-month follow-up.
• The percentage of patients lost to follow-up.
• Whether any imputation methods were used for missing data.

Given the size of the cohort, follow-up completeness is essential for proper interpretation of the reported EWL and TBWL outcomes.

4. Complication reporting should be expanded

The complication profile currently appears incomplete.

The authors report surgical site infection, bruising, and transfusion requirements, but important bariatric surgery outcomes are not clearly presented, including:

• Staple-line leak rate.
• Reoperation rate.
• Readmission rate.
• Venous thromboembolism.
• Conversion to open surgery.

Reporting complications according to the Clavien–Dindo classification would substantially strengthen the manuscript.

5. Selection criteria appear highly restrictive

One of the most interesting aspects of the manuscript is the proposed anatomical selection algorithm. However, the number of exclusion criteria appears substantial, including:

• Large hiatal hernias.
• Previous upper abdominal surgery.
• Long xiphoid-to-umbilicus distance.
• Significant panniculus.
• Left hepatic lobe hypertrophy.

These restrictions raise an important question regarding the general applicability of the technique. The authors should discuss what proportion of patients presenting for bariatric surgery would realistically qualify for MBLSG in routine clinical practice.

6. Results section requires further development

For a cohort of more than 900 patients, the Results section is surprisingly concise.

Additional information would be valuable, including:

1. Operative time.
2. Length of hospital stay.
3. Comorbidity profile.
4. Learning-curve considerations.
5. Readmission rates.
6. Detailed postoperative morbidity.

Such data would considerably improve the scientific value of the manuscript.

7. Claims regarding safety and superiority should be moderated

Several statements throughout the manuscript suggest that MBLSG is safe, effective, and superior in terms of cosmetic outcomes.

While the presented data support feasibility and acceptable short-term outcomes, the current study design does not allow definitive conclusions regarding superiority. The discussion and conclusions should be revised to reflect the observational nature of the study.

Minor Comments

1. Clarify multicenter design

The manuscript is described as a multicenter retrospective study, yet the number of participating centers and patient distribution among centers are not reported.

Please provide:

• Number of participating institutions.
• Case volume per center.
• Whether a standardized operative protocol was used.

2. Improve comparison with previously published BLSG literature

The discussion would benefit from a clearer table summarizing differences between:

• Original BLSG.
• Conventional LSG.

This would help readers better appreciate the technical novelty of the proposed modification.

3. Figures could be improved

The intraoperative images are useful, but their educational value would increase considerably with:

• Anatomical annotations.
• Arrows indicating trocar trajectories.
• Labels highlighting key landmarks.

A schematic illustration of trocar positioning would also be helpful.

4. Editorial corrections

A careful language revision is recommended to improve readability and eliminate several repetitive statements, particularly within the Discussion section.

Author Response

Reviewer 2, Comment 1:

1. Lack of a comparator group

The most important limitation of this study is the absence of a control cohort undergoing conventional laparoscopic sleeve gastrectomy. Throughout the manuscript, the authors repeatedly suggest that MBLSG provides superior cosmetic outcomes and favorable clinical performance. However, without a direct comparison, these statements cannot be adequately supported.

The current study successfully demonstrates feasibility and provides a large descriptive experience, but it does not establish superiority or equivalence relative to standard techniques. The conclusions should therefore be revised accordingly and the language should be more cautious throughout the manuscript.

Our response to Reviewer 2 Comment 1: We sincerely thank the reviewer for this critical and accurate methodological observation. We completely agree that the single-arm, descriptive nature of our study is designed to demonstrate safety, feasibility, and technical standardization in a large cohort, rather than to statistically prove superiority over conventional LSG. In accordance with your recommendation, we have thoroughly reviewed and revised the entire manuscript—including the Abstract, Discussion, and Conclusions. We have removed all terminology implying "superiority" or direct comparative advantages. The language has been appropriately tempered to state that the MBLSG technique "yields high patient-reported cosmetic satisfaction" and demonstrates an "acceptable safety profile." As noted in the Methods section, this large-scale cohort serves as the foundational data for our forthcoming formal comparative analysis.

Reviewer 2, Comment 2:

2. Cosmetic outcomes require better methodological definition

The central rationale for introducing MBLSG is improved aesthetics. Nevertheless, cosmetic outcomes are represented only by a postoperative cosmetic score of 4 ± 0.8.

The authors should clearly explain:

How cosmetic satisfaction was assessed.

Whether the score was patient-reported or investigator-assessed.

At what postoperative time point the evaluation was performed.

Whether a validated cosmetic assessment tool was used.

Whether scar photographs were systematically evaluated.

Without this information, it is difficult to interpret one of the manuscript’s most important outcome measures.

Our response to Reviewer 2 Comment 2: We appreciate the reviewer detailing these crucial methodological points. We entirely agree that the evaluation of cosmetic outcomes requires a transparent description. To address this, we have added a comprehensive "Data Collection and Outcome Measures" subsection to the Materials and Methods.

To answer your specific queries directly:

Cosmetic satisfaction was evaluated using a 5-point Likert scale (1 = completely dissatisfied, 5 = completely satisfied).

The score was entirely patient-reported.

The evaluation was performed during the 12-month postoperative outpatient follow-up visit.

A formally validated psychometric or cosmetic assessment tool was not utilized in this retrospective cohort.

Scar photographs were not systematically evaluated by an independent panel or investigators; the scores reflect the patients' own subjective aesthetic satisfaction.

We have explicitly noted our reliance on a non-validated, self-reported scale without independent photographic evaluation as a limitation in the Discussion section.

Reviewer 2, Comment 3:

3. Incomplete reporting of follow-up

Weight-loss outcomes are reported at 12 months, but the manuscript does not specify:

How many patients completed 12-month follow-up.

The percentage of patients lost to follow-up.

Whether any imputation methods were used for missing data.

Given the size of the cohort, follow-up completeness is essential for proper interpretation of the reported EWL and TBWL outcomes.

Our response to Reviewer 2 Comment 3:  We thank the reviewer for pointing out this critical aspect of data reporting. To ensure the robustness of our weight loss analysis, we utilized a complete-case analysis approach. Out of the initial pool of 958 patients who underwent the MBLSG procedure during the study period, 52 patients were lost to follow-up at the 12-month mark (representing a loss-to-follow-up rate of 5.4%). These patients were excluded from the study cohort. Therefore, the reported cohort of 906 patients consists entirely of individuals who successfully completed their 12-month clinical follow-up. Because we excluded patients with incomplete follow-up data, no statistical imputation methods (e.g., last observation carried forward or multiple imputation) were required or utilized for missing data. We have updated the Materials and Methods section to clearly outline this follow-up protocol.

Reviewer 2, Comment 4:

4. Complication reporting should be expanded

The complication profile currently appears incomplete.

The authors report surgical site infection, bruising, and transfusion requirements, but important bariatric surgery outcomes are not clearly presented, including:

Staple-line leak rate.

Reoperation rate.

Readmission rate.

Venous thromboembolism.

Conversion to open surgery.

Reporting complications according to the Clavien–Dindo classification would substantially strengthen the manuscript.

Our response to Reviewer 2 Comment 4: We sincerely thank the reviewer for this excellent suggestion, which undoubtedly elevates the quality and standardization of our safety reporting. We agree that a comprehensive complication profile utilizing the Clavien-Dindo (CD) classification is essential. We have now expanded the Results section to explicitly include these major bariatric outcomes.

Specifically, in our MBLSG cohort:

Staple-line leak rate: 0%

Venous thromboembolism (VTE): 0%

30-day Readmission rate: 4.5% (41 patients)

Reoperation rate: 0%

Conversion to open surgery: 0%

When stratified by the Clavien-Dindo classification, our complication profile is as follows:

Grade I: Observed in 245 patients (27%), predominantly consisting of minor issues such as surgical site ecchymosis and bruising.

Grade II: Observed in 137 patients (15.1%), encompassing events requiring pharmacological intervention (e.g., surgical site infections) or blood transfusions.

Grades III, IV, and V: 0%. There were no cases of post-sleeve strictures requiring surgical re-intervention, no severe life-threatening complications, and no mortality.

We have thoroughly revised the text to reflect this expanded complication reporting.

Reviewer 2, Comment 5:

5. Selection criteria appear highly restrictive

One of the most interesting aspects of the manuscript is the proposed anatomical selection algorithm. However, the number of exclusion criteria appears substantial, including:

Large hiatal hernias.

Previous upper abdominal surgery.

Long xiphoid-to-umbilicus distance.

Significant panniculus.

Left hepatic lobe hypertrophy.

These restrictions raise an important question regarding the general applicability of the technique. The authors should discuss what proportion of patients presenting for bariatric surgery would realistically qualify for MBLSG in routine clinical practice.

Our response to Reviewer 2 Comment 5: We deeply appreciate the reviewer’s perspective on this crucial point. We acknowledge that the selection criteria for MBLSG are indeed highly restrictive compared to conventional LSG. However, this stringent anatomical algorithm was deliberately established to prioritize patient safety, ensure optimal ergonomic exposure without a dedicated liver retractor, and achieve a 0% intraoperative conversion rate, as detailed in our results.

Regarding general applicability, in our routine clinical practice, this specific technique is predominantly requested by female patients who place a high priority on postoperative cosmetic outcomes (which is reflected in our cohort being 93.1% female). Among this specific demographic presenting for bariatric surgery, we estimate that approximately 60-70% of patients successfully meet all anatomical and clinical prerequisites for the MBLSG procedure. Therefore, while it is not a "one-size-fits-all" operation, its real-world applicability remains highly substantial for the target patient population. We have added a paragraph to the Discussion section to clarify this clinical reality.

Reviewer 2, Comment 6:

6. Results section requires further development

For a cohort of more than 900 patients, the Results section is surprisingly concise.

Additional information would be valuable, including:

Operative time.

Length of hospital stay.

Comorbidity profile.

Learning-curve considerations.

Readmission rates.

Detailed postoperative morbidity.

Such data would considerably improve the scientific value of the manuscript.

Our response to Reviewer 2 Comment 6: We completely agree with the reviewer that a cohort of this magnitude warrants a comprehensive and detailed presentation of clinical outcomes. We have significantly expanded the Results section to address these points.

As detailed in our response to Comment 4, we have already incorporated the 30-day readmission rates and a highly detailed postoperative morbidity profile stratified by the Clavien-Dindo classification.

Furthermore, we have now added the following essential perioperative data to the Results section and updated Table 3 accordingly:

Mean operative time: 26.9 ± 3.4 minutes.

Mean length of hospital stay: 2.0 ± 0.8 days.

Comorbidity profile: Because the primary endpoint of this retrospective study was surgical feasibility and technical standardization, specific individual comorbidities (e.g., exact rates of diabetes or hypertension) were not systematically extracted. However, the overall systemic comorbidity burden of the cohort is comprehensively reflected in the ASA physical status scores provided in Table 3, with 53.1% of patients classified as ASA II and 46.9% as ASA III.

Regarding the learning curve, because the MBLSG procedure relies heavily on the foundational skills required for conventional LSG, the transition is relatively straightforward for experienced bariatric surgeons. The primary learning curve involves adapting to the altered optical axis and establishing the correct trajectory for the initial stapler firing without a direct paraumbilical port. We have added a brief commentary regarding these learning-curve considerations to the Discussion section.

Reviewer 2, Comment 7:

7. Claims regarding safety and superiority should be moderated

Several statements throughout the manuscript suggest that MBLSG is safe, effective, and superior in terms of cosmetic outcomes.

While the presented data support feasibility and acceptable short-term outcomes, the current study design does not allow definitive conclusions regarding superiority. The discussion and conclusions should be revised to reflect the observational nature of the study.

Our response to Reviewer 2 Comment 7: We appreciate the reviewer’s careful evaluation of our manuscript's tone and conclusions. We fully agree that our observational, single-arm study design demonstrates feasibility and short-term safety rather than definitive clinical superiority. As noted in our response to your first comment, we have thoroughly revised the entire manuscript—particularly the Abstract, Discussion, and Conclusions. We have systematically removed all claims of "superiority" and moderated the language to accurately reflect the descriptive nature of our findings. The text now cautiously states that the MBLSG technique "demonstrates an acceptable safety profile" and "yields high patient-reported cosmetic satisfaction," while explicitly acknowledging the need for future comparative trials to establish any definitive comparative efficacy.

Reviewer 2, Comment 8:

Clarify multicenter design

The manuscript is described as a multicenter retrospective study, yet the number of participating centers and patient distribution among centers are not reported.

Please provide:

Number of participating institutions.

Case volume per center.

Whether a standardized operative protocol was used.

Our response to Reviewer 2, Comment 8: We sincerely thank the reviewer for bringing this to our attention, as it allowed us to correct an unintended error in the original manuscript draft. This study is not a multicenter trial; it is a single-center retrospective cohort study. We sincerely apologize for this typographical oversight. All 906 procedures were performed by the same surgical team at a single center, using a strictly standardized surgical protocol. In fact, this single-center design strengthens the validity of our findings by eliminating inter-institutional technical variability and ensuring absolute uniformity in the surgical technique. We have corrected the term "multicenter" to "single-center" and clarified the institutional setting in the Materials and Methods section.

Reviewer 2, Comment 9:

Improve comparison with previously published BLSG literature

The discussion would benefit from a clearer table summarizing differences between:

Original BLSG.

Conventional LSG.

This would help readers better appreciate the technical novelty of the proposed modification.

Our response to Reviewer 2, Comment 9: We deeply appreciate this constructive suggestion. We completely agree that a summary table provides a highly effective visual aid for readers to grasp the specific technical nuances and ergonomic advantages of our modification. To address this, we have created a new table (Table 2) that clearly delineates the differences in port placement, liver retraction methods, visual axis, and cosmetic outcomes among Conventional LSG, the original BLSG, and our MBLSG technique. Furthermore, we have added a corresponding explanatory paragraph in the Discussion section directing the readers to this table to better highlight the technical novelty of our approach.

Reviewer 2, Comment 10:

Figures could be improved

The intraoperative images are useful, but their educational value would increase considerably with:

Anatomical annotations.

Arrows indicating trocar trajectories.

Labels highlighting key landmarks.

A schematic illustration of trocar positioning would also be helpful.

Our response to Reviewer 2, Comment 10: We sincerely thank the reviewer for this excellent and highly constructive suggestion. We completely agree that anatomical annotations and a custom schematic illustration would greatly enhance the educational value of the manuscript. Regrettably, we are unable to provide these enhanced graphics at this time due to technical and resource limitations. We do not have access to professional medical illustration services for the schematic drawing. Furthermore, when we attempted to digitally overlay arrows and text labels onto our original intraoperative video captures, the image resolution degraded significantly, rendering them unsuitable for high-quality journal publication.

To compensate for this graphical limitation, we have meticulously reviewed the "Surgical Technique" section in the manuscript. We have ensured that the textual descriptions of all anatomical landmarks, trocar trajectories, visual axes, and port positionings are detailed with the utmost clarity so that surgeons can accurately visualize the procedure. We sincerely hope the reviewer and the editorial board will understand our technical constraints in this specific regard and find the detailed textual description satisfactory.

Reviewer 2, Comment 11:

Editorial corrections

A careful language revision is recommended to improve readability and eliminate several repetitive statements, particularly within the Discussion section.

Our response to Reviewer 2, Comment 11: We appreciate the reviewer’s careful reading of our manuscript and constructive feedback. We have thoroughly reviewed the entire text, paying special attention to the Discussion section. We have successfully eliminated repetitive statements, streamlined our arguments (particularly regarding the cosmetic outcomes and anatomical limitations), and conducted a comprehensive language revision to enhance the overall readability, academic tone, and flow of the manuscript.

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript describes a large retrospective cohort of 906 patients undergoing Modified Bikini Line Sleeve Gastrectomy (MBLSG), with a detailed technical description, proposed anatomical landmarks, patient-selection criteria and early clinical outcomes. The topic is interesting and potentially relevant, particularly because cosmetic outcomes and scar concealment are increasingly important in bariatric surgery. The large number of patients is a clear strength. However, the paper currently reads more as a technical experience report than as a fully balanced clinical outcomes study. Several claims, especially regarding safety, superiority and reproducibility, require substantial moderation or stronger supporting data.

Introduction

1. The rationale is clear, but the novelty should be defined more precisely.
   The manuscript repeatedly states that this is the first large-scale study validating MBLSG. This may be acceptable if the authors clearly define MBLSG as distinct from previously described BLSG. However, the introduction should explain exactly what is “modified” compared with Abdelbaki’s technique: port number, absence of a dedicated liver retractor, port trajectory, trocar use, patient positioning, or selection criteria. At present, the difference is described later but not sufficiently framed at the beginning.
2. The cosmetic problem needs better quantification.
   The introduction states that postoperative scarring is a significant concern, but no data are provided on how frequently this affects quality of life, body image or patient satisfaction after bariatric surgery. The authors should support this with appropriate literature and explain why cosmetic benefit justifies a modified trocar strategy that may introduce specific technical constraints.

Materials and Methods / Study Design

3. The study design is insufficiently detailed for a cohort of 906 patients.
   The authors should clarify the number of participating centres, case distribution by centre, number of surgeons, surgeon experience, inclusion/exclusion criteria, recruitment period, follow-up completeness and whether the first cases were included during the learning curve. A “multicentre retrospective analysis” requires much more methodological transparency.
4. Patient selection criteria must be operationalised.
   The manuscript provides several anatomical exclusion criteria, including xiphoid–umbilical distance, xiphoid–symphysis pubis distance, xiphoid–ASIS distance, redundant panniculus and left-lobe hypertrophy. However, it is unclear whether these criteria were prospectively applied to all 906 patients, retrospectively derived from experience, or used inconsistently over time. The authors should distinguish between criteria used before surgery and criteria proposed after analysing the cohort.
5. The cosmetic outcome measure is not adequately described.
   The “postoperative cosmetic score” is central to the manuscript but is reported only as a mean value of 4 ± 0.8. The authors must specify the scale, timing of assessment, who administered it, whether it was validated, whether patients were blinded to the purpose of the study, and whether missing data occurred. Without this, the claim of cosmetic superiority is not supported.

Surgical Technique

6. The technical description is valuable but should be reorganised and simplified.
   The surgical section is detailed and useful, particularly regarding port trajectory, the inguinal subcutaneous tunnel, instrument crossing, stapler orientation and liver exposure. However, it is too long and occasionally repetitive. The authors should consider a structured step-by-step table: patient position, port placement, camera transition, dissection sequence, stapling, specimen extraction, closure, and bailout strategy.
7. Safety-critical steps require clearer bailout rules.
   The manuscript acknowledges potential problems with left-lobe hypertrophy, panniculus-related trocar dislodgement, low umbilicus and difficult stapler angulation. These are important observations. The authors should explicitly define when to convert to conventional LSG or add a trocar. This would make the paper more clinically useful and safer for surgeons wishing to reproduce the technique.

Results

8. The results are underreported for a large bariatric series.
   Operative time, conversion/additional trocar rate, length of stay, readmission, reoperation, leak, stenosis, GERD symptoms, portal vein thrombosis, mortality, Clavien–Dindo classification and follow-up rate should be reported. The current outcomes are too limited for a cohort of this size. In particular, stating that there were “no major complications” while only reporting surgical site infection, bruising and transfusion is not sufficient.
9. The infection rate deserves deeper analysis.
   A surgical site infection rate of 6.2% appears relatively high for laparoscopic bariatric surgery and is higher than the comparator series cited in the discussion. The authors attribute this partly to the umbilical port, but this remains speculative. They should provide definitions, severity, management, microbiology if available, distribution by port site and whether the rate decreased with improved umbilical preparation.

Discussion / Conclusions

10. The conclusions must be toned down.
    The manuscript currently states that MBLSG is safe, effective and superior in cosmetic outcomes. Given the retrospective design, lack of control group, unclear cosmetic assessment and short follow-up, the authors should replace “superior” with “associated with high patient-reported cosmetic satisfaction in a selected cohort”. The discussion should more frankly acknowledge that comparative superiority versus conventional LSG remains unproven and should be tested in a prospective controlled study.

I would suggest adding some references to reinforce discussion

1. Shah D, Tesfai FM, Boal M, Arezzo A, Francis N. Evaluation of current and emerging endoluminal robotic platforms using the IDEAL framework. Minim Invasive Ther Allied Technol. 2025 Aug;34(4):253-266. doi: 10.1080/13645706.2025.2467805. Epub 2025 Feb 21. PMID: 39985163.
   Where to insert: Discussion, when addressing innovation, reproducibility and the need for staged evaluation before broad adoption.
   Why: This paper is useful to support the concept that new minimally invasive technologies and modified approaches should be evaluated through a structured framework rather than by large retrospective experience alone. It would help the authors frame MBLSG as an innovation requiring stepwise validation, including long-term outcomes and external reproducibility.
2. Lenssen T, Postema RR, Camenzuli C, Calleja-Agius J, Dankelman J, Horeman-Franse T. A pre-clinical application study of the SATA-LRS laparoscopic instrument in a human cadaver model. Minim Invasive Ther Allied Technol. 2025 Dec;34(6):447-455. doi: 10.1080/13645706.2025.2554077. Epub 2025 Sep 18. PMID: 40964699.
   Where to insert: Surgical technique or Discussion, where the authors discuss instrument crossing, trocar angulation and ergonomic constraints.
   Why: Although not bariatric-specific, this article is relevant because it addresses how laparoscopic instrument design, steering capacity and trocar configuration affect surgical feasibility. This would strengthen the discussion of the technical limitations created by the bikini-line port geometry.
3. Abu Salem S, Goren K, Michael S, Brodie R, Kushnir D, Yagil J, Szydlo Shein G, Helou B, Marom G, Mintz Y. Validation of safety for self-retracting intraperitoneal device for small bowel in minimally invasive surgery. Minim Invasive Ther Allied Technol. 2025 Oct;34(5):378-385. doi: 10.1080/13645706.2025.2500742. Epub 2025 May 21. PMID: 40396652.
   Where to insert: Discussion, in the paragraph dealing with liver exposure, avoidance of an additional trocar and the need for safe retraction strategies.
   Why: This paper is relevant because MBLSG depends heavily on patient positioning and selective avoidance of a dedicated retraction port. A reference on safe intraperitoneal retraction would help contextualise the authors’ claim that adequate exposure can be achieved without an additional trocar in selected patients.

Author Response

Reviewer 3, Comment 1:

Introduction

The rationale is clear, but the novelty should be defined more precisely.

The manuscript repeatedly states that this is the first large-scale study validating MBLSG. This may be acceptable if the authors clearly define MBLSG as distinct from previously described BLSG. However, the introduction should explain exactly what is “modified” compared with Abdelbaki’s technique: port number, absence of a dedicated liver retractor, port trajectory, trocar use, patient positioning, or selection criteria. At present, the difference is described later but not sufficiently framed at the beginning.

Our response to Reviewer 3 Comment 1: We sincerely thank the reviewer for this insightful comment. We completely agree that the specific technical modifications should be explicitly defined early in the Introduction to properly frame the study's novelty and rationale. We have revised the final paragraph of the Introduction section to clearly distinguish our Modified Bikini Line Sleeve Gastrectomy (MBLSG) from Abdelbaki’s original technique. Specifically, we now explicitly state that our modifications center on: (1) an altered diagonal optical trajectory achieved via a specifically placed lateral inguinal port, and (2) the complete elimination of a dedicated liver retractor, relying instead on specific traction vectors. We believe this early clarification significantly strengthens the foundation of our manuscript.

Reviewer 3, Comment 2: The cosmetic problem needs better quantification.

The introduction states that postoperative scarring is a significant concern, but no data are provided on how frequently this affects quality of life, body image or patient satisfaction after bariatric surgery. The authors should support this with appropriate literature and explain why cosmetic benefit justifies a modified trocar strategy that may introduce specific technical constraints.

Our response to Reviewer 3 Comment 2: We deeply appreciate this constructive criticism, which rightly challenges us to strengthen the physiological and psychological rationale for our technique. We have revised the Introduction section to incorporate literature detailing the impact of visible abdominal scarring on body image and quality of life following bariatric surgery.

We highlighted that body image dissatisfaction remains a significant challenge post-weight loss, and visible multipoort scars can act as a constant psychological reminder of the surgery, particularly for young female patients (who comprise over 93% of our cohort). We have explicitly clarified that for this specific demographic—who heavily prioritize aesthetic preservation—the profound psychosocial and cosmetic benefits of concealing scars within the bikini line fully justify the implementation of a modified trocar strategy, despite its associated anatomical selection constraints and specific learning curve.

Reviewer 3, Comment 3: Materials and Methods / Study Design

The study design is insufficiently detailed for a cohort of 906 patients.

The authors should clarify the number of participating centres, case distribution by centre, number of surgeons, surgeon experience, inclusion/exclusion criteria, recruitment period, follow-up completeness and whether the first cases were included during the learning curve. A “multicentre retrospective analysis” requires much more methodological transparency.

Our response to Reviewer 3 Comment 3:  We sincerely thank the reviewer for highlighting the need for absolute methodological transparency in a cohort of this size. We have thoroughly revised the Materials and Methods section to address each of your specific points:

Study Setting & Surgeons: First, we must apologize for a typographical oversight in the original draft; this is not a multicenter study. It is a strictly single-center retrospective analysis. This single-center, single-team design ensures the utmost technical standardization. We have corrected the term "multicenter" throughout the manuscript.

Recruitment Period & Follow-up: Patients were recruited between [April/2020] and [April/2025]. As detailed in our revised text, out of an initial pool of 958 operated patients, 52 were lost to follow-up (a 5.4% attrition rate). The reported cohort of 906 patients represents those with 100% complete 12-month follow-up data.

Inclusion/Exclusion Criteria: The highly restrictive anatomical selection criteria (e.g., absence of large hiatal hernias, specific xiphoid-to-umbilicus distance, absence of significant panniculus or left hepatic lobe hypertrophy) have been further clarified in the revised manuscript to emphasize patient safety.

Learning Curve: The very first cases performed during the initial adoption phase of this technique were included in this cohort of 906 patients. We believe this makes the absence of major complications (0% leak, 0% reoperation, 0% conversion) even more noteworthy, demonstrating the inherent safety and manageable learning curve of the MBLSG procedure for experienced bariatric surgeons.

Reviewer 3, Comment 4: Patient selection criteria must be operationalised.

The manuscript provides several anatomical exclusion criteria, including xiphoid–umbilical distance, xiphoid–symphysis pubis distance, xiphoid–ASIS distance, redundant panniculus and left-lobe hypertrophy. However, it is unclear whether these criteria were prospectively applied to all 906 patients, retrospectively derived from experience, or used inconsistently over time. The authors should distinguish between criteria used before surgery and criteria proposed after analysing the cohort.

Our response to Reviewer 3 Comment 4: We deeply appreciate the reviewer’s methodological rigor regarding this critical point. The evolution of our selection criteria is a key outcome of this study, and we agree that distinguishing between prospectively applied clinical parameters and retrospectively derived anthropometric guidelines is essential.

We have revised the Materials and Methods section to clarify this distinction:

Prospectively Applied Criteria: From the very first case, major clinical contraindications—specifically the presence of a redundant, sagging panniculus, documented left-lobe hepatomegaly, and large hiatal hernias—were strictly and prospectively utilized to exclude patients. This was done to ensure absolute patient safety and to avoid intraoperative conversions.

Retrospectively Derived Guidelines: The specific anthropometric parameters (such as the exact xiphoid–umbilical, xiphoid–symphysis pubis, and xiphoid–ASIS distances) were not strictly measured in millimeters prior to the earliest surgeries. Instead, these precise anatomical distance criteria were retrospectively derived and operationalized into a standardized algorithm based on the cumulative ergonomic challenges and successes observed throughout the 906 procedures. We propose these specific metric guidelines to help future surgeons accurately select ideal candidates and safely navigate the learning curve.

Reviewer 3, Comment 5: The cosmetic outcome measure is not adequately described.

The “postoperative cosmetic score” is central to the manuscript but is reported only as a mean value of 4 ± 0.8. The authors must specify the scale, timing of assessment, who administered it, whether it was validated, whether patients were blinded to the purpose of the study, and whether missing data occurred. Without this, the claim of cosmetic superiority is not supported.

Our response to Reviewer 3 Comment 5: We thank the reviewer for this crucial methodological point. We completely agree that the measurement of cosmetic outcomes requires precise description. We have updated the Materials and Methods section to provide these necessary details:

Scale and Validation: Cosmetic satisfaction regarding abdominal scarring was evaluated using a simple, non-validated 5-point Likert scale (1 = completely dissatisfied, 5 = highly satisfied). While we acknowledge the limitation of not using a externally validated scoring system (such as POSAS), this institutional 5-point scale is routinely used in our clinic for postoperative aesthetic feedback.

Timing and Administration: The score was recorded during the routine 12-month postoperative outpatient follow-up visit. To minimize investigator bias, the questions were administered by outpatient clinical nurses who were independent of the surgical operating team.

Blinding and Missing Data: Given the retrospective, single-arm observational nature of this study, patient blinding was not methodologically feasible. As clarified in our response to Comment 3, the reported score reflects the data of the 906 patients who completed their 12-month follow-up (excluding the 5.4% lost to follow-up).

Moderation of Claims: We entirely agree that without a control group and a validated questionnaire, absolute claims of cosmetic "superiority" cannot be scientifically supported. As noted in our revisions for Reviewer 2, we have thoroughly revised the manuscript to remove all claims of "superiority," and instead conservatively state that the technique "yields high patient-reported cosmetic satisfaction scores.

Reviewer 3, Comment 6: Surgical Technique

The technical description is valuable but should be reorganised and simplified.

The surgical section is detailed and useful, particularly regarding port trajectory, the inguinal subcutaneous tunnel, instrument crossing, stapler orientation and liver exposure. However, it is too long and occasionally repetitive. The authors should consider a structured step-by-step table: patient position, port placement, camera transition, dissection sequence, stapling, specimen extraction, closure, and bailout strategy.

Our response to Reviewer 3 Comment 6: We wholeheartedly agree with the reviewer that streamlining the technical description greatly enhances its educational and practical utility. We have carefully revised the "Surgical Technique" section to eliminate repetitive phrasing and simplify the narrative flow. Most importantly, as per your excellent suggestion, we have synthesized the entire operative workflow into a new, quick-reference table (Table 1). This table clearly structures the procedure into distinct phases—ranging from patient positioning to explicit bailout strategies—providing a highly digestible and systematic guide for surgeons adopting the MBLSG technique.

Reviewer 3, Comment 7: Safety-critical steps require clearer bailout rules.

The manuscript acknowledges potential problems with left-lobe hypertrophy, panniculus-related trocar dislodgement, low umbilicus and difficult stapler angulation. These are important observations. The authors should explicitly define when to convert to conventional LSG or add a trocar. This would make the paper more clinically useful and safer for surgeons wishing to reproduce the technique.

Our response to Reviewer 3 Comment 7: We are highly grateful to the reviewer for emphasizing this critical aspect of patient safety. We completely agree that for a novel surgical technique to be safely reproducible, explicit thresholds for conversion must be defined. To address this, we have added a dedicated subsection titled "Bailout Rules and Conversion Criteria" to the end of the Surgical Technique section. This new section explicitly outlines four absolute clinical scenarios (involving liver retraction failure, unsafe stapler angulation, trocar dislodgement, and bleeding) under which the surgeon must immediately abandon the cosmetic approach and either add a conventional port or convert entirely to a standard multi-port LSG. We believe this addition significantly enhances the clinical utility and safety profile of our manuscript.

Reviewer 3, Comment 8: Results

The results are underreported for a large bariatric series.

Operative time, conversion/additional trocar rate, length of stay, readmission, reoperation, leak, stenosis, GERD symptoms, portal vein thrombosis, mortality, Clavien–Dindo classification and follow-up rate should be reported. The current outcomes are too limited for a cohort of this size. In particular, stating that there were “no major complications” while only reporting surgical site infection, bruising and transfusion is not sufficient.

Our response to Reviewer 3, Comment 8: We completely agree with the reviewer that a 906-patient cohort necessitates highly detailed and rigorously classified outcome reporting. In accordance with similar feedback from other reviewers, we have fundamentally restructured and significantly expanded the Results section.

Reviewer 3, Comment 9: The infection rate deserves deeper analysis.

A surgical site infection rate of 6.2% appears relatively high for laparoscopic bariatric surgery and is higher than the comparator series cited in the discussion. The authors attribute this partly to the umbilical port, but this remains speculative. They should provide definitions, severity, management, microbiology if available, distribution by port site and whether the rate decreased with improved umbilical preparation.

Our response to Reviewer 3, Comment 9: We sincerely appreciate the reviewer’s astute observation regarding the surgical site infection (SSI) rate. We entirely agree that a 6.2% SSI rate warrants thorough explanation, as it is indeed higher than the standard upper-abdominal multi-port LSG literature. We have significantly expanded the Results and Discussion sections to provide a deeper analysis of this specific complication.

In the revised Results, we clarified the following:

Definition & Severity: All reported SSIs were strictly superficial incisional infections (Clavien-Dindo Grade I or II). There were zero cases of deep fascial dehiscence, evisceration, or intra-abdominal abscesses.

Distribution: The infections were overwhelmingly localized to the paraumbilical port and the suprapubic port hidden within the lower abdominal skin fold.

Management & Microbiology: All cases were managed conservatively with local wound dressings and targeted oral antibiotics. Where microbiological swabs were obtained, the predominant organisms were typical skin flora (Staphylococcus aureus).

In the revised Discussion, we addressed the etiology. The higher SSI rate is anatomically inherent to the MBLSG approach in obese patients. Lower abdominal incisions reside in moist skin folds prone to maceration and friction, and the umbilicus is notoriously difficult to sterilize. Importantly, as we progressed through our cohort, we implemented a rigorous preoperative protocol involving aggressive umbilical cleaning (chlorhexidine swabbing) and meticulous postoperative drying of the bikini line folds. Following the implementation of these specific skin-preparation measures, our SSI rate demonstrated a marked decrease in the latter half of the series.

Reviewer 3, Comment 10: The conclusions must be toned down.

The manuscript currently states that MBLSG is safe, effective and superior in cosmetic outcomes. Given the retrospective design, lack of control group, unclear cosmetic assessment and short follow-up, the authors should replace “superior” with “associated with high patient-reported cosmetic satisfaction in a selected cohort”. The discussion should more frankly acknowledge that comparative superiority versus conventional LSG remains unproven and should be tested in a prospective controlled study.

Our response to Reviewer 3, Comment 10: We completely agree with the reviewer’s assessment and highly appreciate the exact phrasing provided. As we also noted in response to similar feedback, we fully recognize that our single-arm retrospective design precludes any definitive claims of clinical or cosmetic "superiority." We have thoroughly revised the Conclusions and Discussion sections to completely remove the term "superior." Adopting your precise recommendation, the manuscript now conservatively concludes that the MBLSG technique is "associated with high patient-reported cosmetic satisfaction in a selected cohort." Furthermore, we have explicitly stated in our final paragraph that comparative superiority versus conventional LSG remains unproven and must be rigorously tested in future prospective, randomized controlled trials.

Reviewer 3, Comment 11: I would suggest adding some references to reinforce discussion

Shah D, Tesfai FM, Boal M, Arezzo A, Francis N. Evaluation of current and emerging endoluminal robotic platforms using the IDEAL framework. Minim Invasive Ther Allied Technol. 2025 Aug;34(4):253-266. doi: 10.1080/13645706.2025.2467805. Epub 2025 Feb 21. PMID: 39985163.

Where to insert: Discussion, when addressing innovation, reproducibility and the need for staged evaluation before broad adoption.

Why: This paper is useful to support the concept that new minimally invasive technologies and modified approaches should be evaluated through a structured framework rather than by large retrospective experience alone. It would help the authors frame MBLSG as an innovation requiring stepwise validation, including long-term outcomes and external reproducibility.

Lenssen T, Postema RR, Camenzuli C, Calleja-Agius J, Dankelman J, Horeman-Franse T. A pre-clinical application study of the SATA-LRS laparoscopic instrument in a human cadaver model. Minim Invasive Ther Allied Technol. 2025 Dec;34(6):447-455. doi: 10.1080/13645706.2025.2554077. Epub 2025 Sep 18. PMID: 40964699.

Where to insert: Surgical technique or Discussion, where the authors discuss instrument crossing, trocar angulation and ergonomic constraints.

Why: Although not bariatric-specific, this article is relevant because it addresses how laparoscopic instrument design, steering capacity and trocar configuration affect surgical feasibility. This would strengthen the discussion of the technical limitations created by the bikini-line port geometry.

Abu Salem S, Goren K, Michael S, Brodie R, Kushnir D, Yagil J, Szydlo Shein G, Helou B, Marom G, Mintz Y. Validation of safety for self-retracting intraperitoneal device for small bowel in minimally invasive surgery. Minim Invasive Ther Allied Technol. 2025 Oct;34(5):378-385. doi: 10.1080/13645706.2025.2500742. Epub 2025 May 21. PMID: 40396652.

Where to insert: Discussion, in the paragraph dealing with liver exposure, avoidance of an additional trocar and the need for safe retraction strategies.

Why: This paper is relevant because MBLSG depends heavily on patient positioning and selective avoidance of a dedicated retraction port. A reference on safe intraperitoneal retraction would help contextualise the authors’ claim that adequate exposure can be achieved without an additional trocar in selected patients.

Our response to Reviewer 3, Comment 11: We sincerely thank the reviewer for pointing out these highly relevant and insightful papers. We completely agree that incorporating these concepts significantly broadens the academic perspective of our manuscript. We have carefully integrated all three suggested references into the Discussion section:

We cited Shah et al. when discussing the necessity of structured, staged validation (such as the IDEAL framework) for surgical innovations before advocating for widespread adoption.

We incorporated Lenssen et al. into the paragraph addressing the biomechanical and ergonomic constraints (such as instrument crossing and trocar angulation) inherent to the altered geometry of the bikini-line ports.

We referenced Abu Salem et al. when discussing our strategy for liver exposure, contextualizing our approach within the broader evolving literature on safe, alternative retraction strategies that minimize dedicated working ports.

We believe these additions have thoroughly reinforced the depth of our discussion.