A Simple Strategy in Avulsion Flap Injury: Prediction of Flap Viability Using Wood's Lamp Illumination and Resurfacing with a Full-thickness Skin Graft

Abstract

Background: Extensive degloving injuries of the extremities usually result in necrosis of the flap, necessitating comprehensive skin grafting. Provided there is a sufficient tool to evaluate flap viability, full-thickness skin can be used from a nonviable avulsed flap. We used a Wood's lamp to determine the viability of avulsed flaps in the operation field after intravenous injection of fluorescein dye.

Methods: We experienced 13 cases during 16 months. Fifteen minutes after the intravenous injection of fluorescein dye, the avulsed skin flaps were examined and non-fluorescent areas were marked under Wood's lamp illumination. The marked area was defatted for full-thickness skin grafting. The fluorescent areas were sutured directly without tension. The non-fluorescent areas were covered by defatted skin. Several days later, there was soft tissue necrosis within the flap area. We measured necrotic area and revised the flap.

Results: Among all the cases, necrotic area was 21.3% of the total avulsed area. However, if we exclude three cases, one of a carelessly managed patient and two cases of the flaps were inappropriately applied, good results were obtained, with a necrotic area of only 8.4%. Eight patients needed split-thickness skin grafts, and heel pad reconstruction was performed with free flap.

Conclusions: A full-thickness skin graft from an avulsed flap is a good method for addressing aesthetic concerns without producing donor site morbidity. Fluorescein dye is a useful, simple, and cost-effective tool for evaluating flap viability. Avulsed flap injuries can be managed well with Wood's lamp illumination and a full-thickness skin graft.

Keywords: Dermis; Extremities; Skin transplantation; Soft tissue injuries; Tissue survival.

Conflict of interest statement

No potential conflict of interest relevant to this article was reported.

Figures

Fig. 1

Intraoperative photographs demonstrate the authors' methods (A) Under Wood's lamp illumination areas of fluorescence and non-fluorescence and mottled areas can be distinguished. (B) The flap of the non-fluorescent area is defatted to be used as FTSG. (C) To prevent hematoma formation under FTSG, VAC dressing is applied. FTSG, full-thickness skin graft; VAC, vacuum-assisted closure.

Fig. 2

Case 1: preoperative and postoperative photographs (A) Circumferential avulsed skin flap injury from the thigh to the dorsum of the foot was noted. (B) Multiple but small areas of necrosis were found. (C) An acceptable appearance was reported at a follow up at 2 months.

Fig. 3

Case 2: preoperative and postoperative photographs (A) An avulsion flap injury was noted on the lateral surface of the foot. (B) Well recovered skin was found.

Fig. 4

Case 4: preoperative and postoperative photographs (A) A circumferential degloving injury was noted on the lower leg. (B) A non-defatted area on dependent position changed to necrosis after the 6th postoperative day. (C) No functional impairment was found, but a depression was noted at the posterior calf.