Fast and Thin: Subdermal Dissection of Pure Skin Perforator Flaps in Pediatric Extremity Trauma

We recently had the pleasure of reading the manuscript by Glass et al., “Thin and superthin free flaps: An innovative approach to pediatric extremity reconstruction.” The authors of this paper described in a case series, the use of thin and super-thin flaps in pediatric extremity reconstruction in the context of open fractures. They reported favorable functional and esthetic outcomes, as well as less donor site morbidity compared to traditional “bulkier” flaps. We concur with the findings of this study that thinner flaps provide better outcomes in cases of pediatric extremity trauma. However, we propose to take it a step further; we believe subdermally dissected pure skin perforator (PSP) flaps are even better suited for the task. First reported by Narushima et al., in 2011, the PSP flap boasts the thinness of a skin graft, while also conserving the benefit of skin flaps such as less wound contracture, better esthetic outcomes, and faster healing. Since then, PSP flaps have been reported in a wide variety of use cases, including open fractures. ^{,  ,}  Despite the many advantages of the PSP flap, its use is still limited. This is largely because of the tedious thinning process where the microsurgeon must meticulously excise the fatty tissue after identifying the perforator and dissecting the flap at the superficial or deep fascial plane. Recently, Yamamoto et al., has proposed a new method called subdermal dissection which substantially simplifies and expedites the process of raising a PSP flap. Instead of identifying the flap perforator at a deeper layer first then dissecting outwards in a process that would require thinning, they propose starting by dissecting the flap at the subdermal layer and then moving proximally to identify the perforator entering the dermis. Using this method, Yamamoto showed surgeon who has experience in reconstructive microsurgery is able to raise a PSP flap within 30 min. A rapidly elevated PSP flap could be immensely useful in time-constrained trauma cases. Furthermore, since PSP flaps are thinner than super-thin and thin flaps, they should provide superior esthetic and functional outcomes. This is especially so when the recipient is near a joint area or in areas where there is little subcutaneous tissue between the skin and bone.