Comments on “Basics and Applications of the Fusuma Sliding Flap: A Versatile Method for Reconstruction of Full-thickness Defects of the Lower Lip”

To the Editor,

Kasai et al.¹⁾ provide a noteworthy and technically refined approach to lower lip reconstruction with their case series utilizing the Fusuma sliding flap. They report consistent flap survival, satisfactory functional results, and durable outcomes in nine patients presenting with full-thickness, full-width defects of the lower lip¹⁾. This contribution enriches the array of reconstructive options available for lower lip carcinoma, a challenging condition that demands careful consideration of oncologic control, restoration of oral function, and aesthetic outcomes^2,3).

A few additional points may further contextualize the clinical utility of the Fusuma flap, especially as reconstructive surgeons weigh the benefits of various local and free flap techniques.

Versatility Compared to Traditional Techniques

The Fusuma sliding flap offers several advantages compared to established local flaps (e.g., Karapandzic, Abbé-Estlander, Webster), including its application over a range of defect sizes, preservation of sphincteric continuity, and avoidance of staged flap division or pedicle delay^2-4). It would enhance the paper if the authors described their criteria for choosing the Fusuma method vs. alternative flaps in specific patients. For instance, did defect size (especially when exceeding the commissure), patient age, or dental status influence flap design or selection? More detailed reporting here would aid reproducibility and surgical planning.

Functional Outcomes and Objective Measures

Kasai et al.¹⁾ report satisfactory outcomes in speech, feeding, and sensation¹⁾. While these domains are clinically relevant, incorporating validated functional outcome measures, such as the Lip Function Score or patient-reported outcome instruments, would strengthen future studies. For instance, the importance of standardized functional and aesthetic assessments in lip reconstruction, which is crucial for improving objective evaluation and facilitating comparison across techniques, has been highlighted in previous work²⁾. Additionally, postoperative oral competence (e.g., drooling, speech intelligibility) and smile symmetry are critical to quality of life and would benefit from more detailed reporting⁵⁾.

Revision Surgery in Commissure-Involving Defects

The authors note that revision surgery was necessary in cases where the defect involved the oral commissure (the corner of the mouth)¹⁾. This is an important observation because defects crossing the commissure are more complex to reconstruct. According to Kasai et al.¹⁾, three of nine patients required commissuroplasty, a surgical procedure to repair or reshape the mouth's corner, especially when the defect extended beyond the commissure into the buccal mucosa. It would be helpful if the authors provided more details about the reasons for these revisions: Were they done to improve appearance, restore function (such as correcting microstomia or a reduced mouth opening), or address flap contraction? Given the complexity of the oral commissure's anatomy and movement, future research could explore modifications to the Fusuma flap, such as adding support around the commissure or combining it with other flaps to reduce the need for revision surgery.

In conclusion, Kasai et al.¹⁾ contribute a highly practical and reproducible approach to lower lip reconstruction that appears both reliable and versatile. As local flap techniques continue to evolve alongside free tissue transfer, options like the Fusuma sliding flap offer an appealing balance of simplicity, safety, and function, particularly in patients with lower lip carcinomas who may have limited comorbidities or are in resource-constrained settings.

We commend Kasai et al.¹⁾ for their valuable contribution to the evolving landscape of lip reconstruction techniques.

Sincerely,

Ethan Jarvis

Wilhelm Hansen

Conflicts of Interest: There are no conflicts of interest.