Response to letter to the editor iwj-23-840

We appreciate this researcher's careful reading of our published article and their insightful questions regarding our research in light of the latest studies. We genuinely welcome the researcher's inquiries and are open to engaging in a discussion to share our perspectives.

Research has shown that skin-fat composite grafts (SFCG), including the subcutaneous superficial layer of fat, can be easily revascularized to improve survival rates.¹ Upon carefully reviewing the referenced articles cited by the author, we found that the researchers described the preservation of the subdermal vascular plexus in the SFCG. Thinner fat layers do not serve as mechanical barriers but instead expose more vascular ends, facilitating early revascularization. SFCG are similar to the free skin grafts with subdermal vascular plexus (FSG-SVP) proposed by researchers in the 1980s,² as both preserve the subdermal vascular plexus and a small amount of fat.

Studies have found that the survival of such grafts mainly depends on the anastomosis between the vascular network surrounding the grafts, its base and the recipient area's blood vessels.^{3, 4} The reconstruction of the grafts' blood supply takes two forms: one is the ingrowth of capillary buds from the recipient site into the flap, including the ingrowth into the transformed vascular lumen, that is, the insertion of neo-capillaries into the original vascular lumen; the other is the mutual anastomosis between the capillaries of the flap and those of the wound bed, allowing the preservation of the flap's original vascular network as permanent vessels.

While FSG-SVP has advantages over full-thickness skin grafts (FTSG) in terms of survival, there is currently no research evidence showing that the grafts’ survival rate or the time required for blood supply reconstruction is superior in FSG-SVP compared to FTSG. Additionally, the quality of survival for FSG-SVP depends on the grafts' structural and growth characteristics, and the grafting technique also affects it. Factors such as damage to the vascular network during flap trimming, excessive thickness of the subcutaneous fat carried by the flap, uncontrolled wound infection, inadequate haemostasis, improper fixation, uneven pressure or insufficient time can all affect the quality of grafts’ survival. Therefore, FSG-SVP requires higher technical demands for grafting.

It is important to note that while FSG-SVP has advantages, they also have limitations, including limited stability in survival and a tendency to develop epidermal blisters and mottling, which restrict their clinical application and promotion. Our study focused on the traditional transplantation method of FTSG to ensure grafts’ survival in the recipient area while preserving the fat in the donor area to minimize its impact on the donor site morphology.

Regarding the adverse factors affecting donor site healing frequently found in trauma patients mentioned by the researcher, we acknowledge that these factors have a significant impact on donor area wound healing. However, it is important to mention that our research did not include these factors in the study's baseline data, which is a limitation. Therefore, our research is currently only applicable to individuals without multiple risk factors complicating the trauma. Undoubtedly, the effective healing of the donor site wound is a crucial factor that significantly impacts surgical outcomes. In our study, our primary focus lies in ensuring the successful healing of the donor area. Simultaneously, during the acquisition of full-thickness skin grafts, we aim to preserve as much donor site fat as possible to minimize its impact on the morphology of the donor site. Therefore, the risk factors highlighted by this researcher indeed reflect a constraint within our study.

Thank you for allowing us to address these concerns.

CONFLICT OF INTEREST STATEMENT

The authors declare no conflicts of interest.