Early skin graft necrosis delimitation by postoperative laser speckle analysis

Abstract

Abstract Necrosis complicates up to 60% of skin grafts, but its extension might take several weeks to become fully established. Physical examination has poor accuracy in its early prediction. Laser speckle contrast imaging (LSCI) is a noncontact, in vivo, validated technology for the study of microcirculation of skin grafts. We sought to assess, in humans, if it is possible (with LSCI) to predict on day (D) 14 the extension of skin graft necrosis on D28. Ten consecutive adult patients who underwent skin malignancy excision on the face (n=3), scalp (n=2), forearm (n=2), pretibial region (n=2) or plantar surface (n=1) and skin graft closure were included. Skin graft perfusion was assessed with LSCI on D14, and hypoperfused regions were highlighted. Clinical pictures of skin grafts on D28 were evaluated, and established necrotic regions were delimited. Then, we assessed whether hypoperfused regions identified on D14 overlapped, in location and size, with those regions of established clinical necrosis on D28. Graft necrosis extension on D28 ranged from 0.5-21% on the face, 12-48% on the scalp, 0-15% on the forearm, 31-45% on the leg and 15% on the plantar surface. Approximately 89% (17 out of 19) of individual hypoperfused regions identified on D14 were also present on D28. The median extent of necrosis on D28 was 21% of the graft area, while on D14, hypoperfused regions corresponded to 23% (p=0.23). We demonstrated that it is possible to predict and delimitate necrotic regions of skin grafts in a relatively early stage by LSCI. On D28, they extensively overlapped with the LSCI hypoperfused regions on D14. Therefore, we can identify the subset of patients at high risk of graft necrosis and anticipate the need for prolonged medical and wound care.