Editor’s Comments

This article provides a practical and effective technique for managing significant vessel size discrepancies in microvascular anastomosis, focusing on partial lumen obliteration with a horizontal mattress corner stitch. The method is particularly suited for discrepancies of 1:4 or greater, addressing a common challenge in reconstructive surgery. Readers in the medical field will find this study valuable for its straightforward and reproducible approach, which offers a solution with a minimal learning curve. The article's importance lies in its potential to improve surgical outcomes and efficiency, making it a must-read for practitioners seeking to enhance their skills in microsurgery. The expertise demonstrated in this study supports its merit for publication, provided that specific aspects are addressed and resolved. This article showcases a solid, practical contribution to the field of reconstructive surgery.

1. As per our author guidelines, key images extracted from videos must be included in the manuscript. These visuals serve to elucidate complex procedures, enhance understanding, and offer reference points for readers who may not be able to view the videos. They underscore critical steps, augment textual descriptions, and provide significant educational value. Below is an example for your reference:
    

   

   RevisionThe authors appreciate the valuable suggestions and guidance provided. These recommendations are crucial for enhancing the clarity and educational value of the manuscript. In accordance with the guidelines, key images extracted from the videos have been incorporated into the article. These visuals serve to elucidate complex procedures, highlight critical steps, and provide reference points for readers who may not be able to view the videos. The images can be found on pages 7 and 8. The authors express their gratitude to the editor for the thoughtful input.
    
2. The authors assert that their technique has a minimal learning curve, suggesting simplicity and ease of adoption. However, the article lacks a detailed explanation to support this claim. The discussion references several techniques for managing a size discrepancy of 1:4 or greater, including V-plasty, sleeve technique, and spatulated anastomosis. To substantiate their claim, I recommend that the authors provide a comparative analysis highlighting the advantages and disadvantages of their technique relative to these established methods. Including a comparison table would offer valuable insights into why their technique is simpler and more effective for managing significant vessel size mismatches. The following example illustrates this approach:
    

   

   

   RevisionIn response to the editor's insightful comments highlighting the need for a detailed explanation to support the claim of a minimal learning curve for the technique, the authors have made significant additions to the manuscript. The revised discussion now includes a comparative analysis of the proposed technique against other established methods, such as V-plasty, sleeve technique, and spatulated anastomosis, to substantiate the claim of simplicity and ease of adoption. Additionally, a comparison table has been included to further illustrate these points, providing valuable insights into the advantages and disadvantages of the technique relative to other established methods. This comprehensive analysis enhances the manuscript's credibility and utility, offering a clear rationale for the proposed technique's ease of use and effectiveness. The manuscript now includes this detailed discussion and comparative analysis on lines 52 to 75, along with a comparison table, to support the claim regarding the technique's simplicity and minimal learning curve.

Reviewer 1 Comments

This article addresses a crucial aspect of reconstructive surgery by presenting a technique for managing significant vessel size discrepancies in microvascular anastomosis, specifically using partial lumen obliteration with a horizontal mattress corner stitch. This method is particularly relevant for discrepancies of 1:4 or greater, which are common and challenging in surgical practice. The practical nature of this approach is noteworthy for its simplicity and ease of replication, potentially improving surgical efficiency and patient outcomes. However, the study's impact is limited by its small sample size, with only four cases presented. This restricts the ability to draw robust conclusions and generalize the findings. To meet the rigorous standards of publication, additional data from larger clinical trials are necessary to validate the technique's efficacy and safety comprehensively. While the current findings are promising, the presence of these critical issues suggests the article is not yet fit for publication in its current guise.

1. The manuscript would benefit from a detailed discussion on the specific criteria used to select patients for this technique. Are there particular patient factors, such as age, comorbidities, type, and location of defects, that influence the suitability of this method? Additionally, do patients with severe vascular diseases or coagulopathies require alternative approaches? The authors are encouraged to clarify these criteria within the manuscript to provide a clearer understanding of the patient selection process and ensure the technique's applicability in diverse clinical scenarios.
   RevisionIn response to the suggestion for a detailed discussion on patient selection criteria, the authors have enhanced the manuscript to provide clarity on this aspect. The updated text includes specific criteria and contextual information about the application of the technique. The authors state: "We have used this technique in four patients, all of whom underwent microvascular reconstruction following head and neck oncologic resection. The internal jugular vein (IJV) or its tributaries are preferred as the first choice for recipient veins. In cases of significant size mismatch (>1:4), an end-to-side anastomosis is generally performed if the donor vein reaches the IJV. However, in certain instances, such as when dealing with an oblique branch of an anterolateral thigh flap, the donor vein may not reach the IJV for an end-to-side anastomosis. In these rare situations, an end-to-end anastomosis with a tributary of the IJV is performed. This combination of significant size mismatch (>1:4) and insufficient donor vein length is extremely uncommon. In our experience with over 500 free flaps over the past six years, we encountered only four such cases, and we have not encountered these scenarios in extremity or breast reconstruction" (lines 18-30). This addition aims to provide a clearer understanding of the patient selection process and the specific conditions under which this technique is applied, ensuring its applicability in diverse clinical scenarios. This detailed explanation helps to contextualize the technique's use and offers insights into the decision-making process behind patient selection, thereby enhancing the manuscript's comprehensiveness and utility for clinicians.
    
2. The authors mention successful outcomes in the four cases over six years. Given that long-term outcomes are critical for determining the efficacy of a technique, the authors are encouraged to include detailed follow-up information in the manuscript. This would provide a comprehensive evaluation of the technique's long-term efficacy and reliability.
   RevisionIn response to the recommendation for detailed follow-up information to evaluate long-term outcomes, the authors have included specific details in the manuscript regarding the outcomes of the four cases studied over a period of six years. They state: "All patients experienced uneventful healing with a minimum of six months of follow-up. During this period, there were no instances of venous congestion or flap loss. It is noteworthy that all our patients underwent head and neck cancer-related reconstructions, which typically do not involve long-term follow-up in our practice" (lines 49-51). This addition aims to provide a clearer understanding of the immediate postoperative results and acknowledges the limitations related to the longer-term follow-up of these specific patient cases. This clarification helps to set realistic expectations about the scope of data available and underscores the need for further research to assess the technique's efficacy over extended periods.
    
3. The study's limitations must be acknowledged. Given that only four cases underwent the procedure, future validation through large-scale clinical trials is necessary to establish the technique's efficacy. Additionally, the absence of a control group limits definitive conclusions. Factors influencing the choice of microvascular anastomosis include surgeon preference, operative experience, and the anatomy of the recipient and donor pedicle vessels. Since no single technique is universally suitable, decisions should be made on a case-by-case basis. Although the authors propose an easy-to-use technique with a minimal learning curve, it is prudent for microsurgeons to train in various precise microsurgical techniques and master one or two for routine use. Including these points in the manuscript will ensure comprehensiveness and provide a clear understanding of the technique's applicability and limitations.
   RevisionIn response to the insightful feedback concerning the need to acknowledge the study's limitations, the authors have addressed these concerns in the manuscript. The newly added text acknowledges the small sample size and the absence of a control group as significant limitations that could affect the study's generalizability and the strength of its conclusions. The manuscript now states: "The limitations of the study include the small sample size and the lack of a control group. Future validation through large-scale clinical trials is essential to establish the technique's efficacy. Establishing a control group presents challenges due to the rarity of this technique's indication" (lines 106-108). Furthermore, the authors have enriched the manuscript with a discussion on potential pitfalls and viable solutions, enhancing the understanding of the technique's practical application and its limitations. This discussion is detailed in lines 95-105, providing readers with a comprehensive view of the microsurgical technique's context, applicability, and adaptability based on specific clinical scenarios. This addition aims to ensure the manuscript's comprehensiveness and clarify the proposed technique's applicability and limitations effectively.

Reviewer 2 Comments

This article makes a valuable contribution to plastic surgery by introducing a technique for managing large vessel size discrepancies in microvascular anastomosis. The authors report successful outcomes in four cases over six years, but more detailed long-term follow-ups are necessary. It’s important to identify specific patient selection criteria, such as age, comorbidities, and defect type. The technique should address intraoperative challenges, especially the risks of turbulence and thrombosis from angled anastomosis. Ensuring a smooth transition and alignment between vessels is crucial. This practical and replicable approach offers valuable insights for improving surgical efficiency and patient outcomes, potentially advancing microsurgical procedures in plastic surgery. The article has the potential for publication, pending a few minor corrections.

1. In the Discussion section, the authors acknowledge that while the lumen obliteration technique has been previously described, there is a notable lack of detailed literature or video demonstrations on the method [4]. Although reference 4 mentions lumen obliteration for managing vessel size discrepancies, it primarily focuses on methods such as "gathering" or reducing the circumference of the larger vessel through techniques like wedge resection. These approaches, while conceptually similar, differ significantly in execution from the technique presented in this article. This distinction suggests the uniqueness of the authors' method. If no identical technique exists in the current literature, this highlights its potential as a novel and valuable contribution to the field. The authors are encouraged to update the manuscript to clearly emphasize this point, thereby positioning their technique as an innovative addition to the existing methodologies for managing significant vessel size discrepancies.
   RevisionThe authors thank the reviewer for the valuable feedback provided on the manuscript. In response, the authors have updated the Discussion section to more accurately underscore the uniqueness and potential novelty of the lumen obliteration technique as compared to those detailed in the literature. Existing methods, such as "gathering" or wedge resection, aim to reduce the circumference of the larger vessel, whereas the technique introduced in this manuscript employs partial lumen obliteration with sutures followed by end-to-end anastomosis—a method distinctly lacking in detailed descriptions and video demonstrations. Detailed outcomes of the technique applied in four patients undergoing microvascular reconstruction following head and neck oncologic resection have been included, highlighting the absence of venous congestion or flap loss after at least six months of follow-up (lines 49-51). Additionally, the manuscript elaborates on the clinical scenarios involving this technique, such as when faced with a significant size mismatch (>1:4) and when the donor vein does not reach the internal jugular vein, necessitating an end-to-end anastomosis with a tributary (lines 18-28). A new section on pitfalls and solutions encountered during the application of this technique adds depth to the discussion (lines 95-105). References to similar lumen-obliterating techniques by other authors are included, noting that although the method aligns in principle with these earlier approaches, the absence of detailed procedural content in existing literature emphasizes the value of the contribution made by this manuscript (lines 81-89). With these updates, the manuscript now more effectively communicates the unique aspects of the introduced technique and its contribution to the field, providing a clear, comprehensive guide to its application in clinical settings.
    
2. There appears to be an angle at the anastomosis site due to the mismatched vessels. This could potentially disrupt the smooth transition between vessel diameters, which is crucial for maintaining laminar flow and minimizing turbulence. Such disruption can induce turbulent blood flow, increasing the risk of platelet aggregation and thrombosis. Irregular flow patterns and stasis at the angled site may lead to clot formation. Could you elaborate on your strategy to mitigate these risks and ensure a smooth transition and alignment between vessels? For instance, do you employ precise suturing techniques, use intraoperative Doppler ultrasound for flow confirmation, and manage tension to prevent distortion, thereby maintaining laminar flow and minimizing complications?
   Revision In response to the reviewer's concerns about the potential angle at the anastomosis site and its implications for turbulent blood flow and thrombosis, the authors have addressed these issues by incorporating specific physiological insights into the manuscript. They acknowledge the inherent challenges posed by the three-dimensional anatomy in head and neck reconstructions, which may lead to some inevitable angular discrepancies at the anastomosis sites. The manuscript elaborates on strategies to mitigate these risks, emphasizing the unique physiological properties of the internal jugular vein (IJV) used as the recipient vein. The authors explain, "Turbulent flow across the anastomosis, resulting from the sudden transition in vessel sizes, presents a known risk factor for thrombosis. However, employing the IJV as the recipient vein utilizes its physiological response to inspiratory fall in intrathoracic pressure, which creates a sucking effect on venous return. This effect significantly reduces the risk of stasis or turbulence within the larger vein." Consequently, the need to taper the larger vessel (IJV tributary) is obviated by this physiological advantage (lines 67-80). This addition to the manuscript clarifies how the authors leverage anatomical and physiological understanding to address potential complications in microvascular anastomosis, specifically in the context of head and neck surgeries where such challenges are prevalent.
    
3. While the authors report no complications in the four cases described, potential complications could arise from the partial lumen obliteration technique, including thrombosis, stenosis, and intimal damage. Accurate lumen matching and gentle vessel handling are crucial to mitigating these risks and should be emphasized in the manuscript. Additionally, intraoperative challenges such as precise lumen matching and maintaining vessel integrity may present difficulties. Did you utilize Doppler ultrasound to assess blood flow and verify anastomosis integrity during the operation to address these challenges?
   Revision The reviewer's concerns regarding potential complications arising from the partial lumen obliteration technique, such as thrombosis, stenosis, and intimal damage, have been addressed comprehensively in the manuscript. The authors have added detailed discussions emphasizing the importance of accurate lumen matching and gentle vessel handling, which are critical for mitigating these risks. Additionally, the manuscript has been updated to include that the integrity and patency of the anastomosis were rigorously assessed intraoperatively using Acland’s test. This method is highlighted to assure readers of the effectiveness of the technique in ensuring successful surgical outcomes. These additions, specified in lines 90-93, clarify the approach taken to address potential intraoperative challenges and verify anastomosis integrity during the operation.

Editorial Comments

1. In adherence to our publication's established standards, we respectfully request the inclusion of each author's academic and professional credentials, such as "MD" or "MD, PhD." Including these credentials allows readers to evaluate the authors' expertise and professional qualifications, thereby enhancing the overall credibility and integrity of the published material.
   Revision The authors have updated the title page to include their academic and professional credentials, specifically "MCh." This enhancement allows readers to assess the authors' expertise and qualifications, thereby enriching the credibility and scholarly integrity of the published material.
    
2. Please revise the title to be brief and informative. For instance, "A Simplified End-to-End Anastomosis Technique for Large Vessel Size Discrepancies with Minimal Learning Curve."
   Revision In response to the request for a more concise and informative title, the authors have revised the title to "A Simplified Technique for Large Vessel Size Discrepancies: Partial Lumen-Obliteration With Sutures Followed by End-To-End Anastomosis." This change has been applied to both the manuscript file and the title page, ensuring consistency across all documentation associated with the publication. This update enhances the clarity and focus of the article, making it more accessible to readers.

Naalla R, Samantaray SA. A simplified technique for large vessel size discrepancies: Partial lumen-obliteration with sutures followed by end-to-end anastomosis. Int Microsurg J. 2024;8(1):4. https://doi.org/10.24983/scitemed.imj.2024.00187