Clinical evaluation of flap viability with a dermal surface fluorometer

A dermal surface fluorometer was used to monitor vascular perfusion in 22 patients who underwent reconstructive surgical procedures with a variety of flaps (e.g., skin flaps, musculocutaneous flaps, fasciocutaneous flaps, and Z-plasties). Sodium fluorescein (1.5 mg per kilogram of body weight) was administered intravenously at the completion of the operative procedure. Quantitative fluorescence readings were obtained at different points in each flap by means of the surface fluorometer (Fluoroscan). The readings were taken at several time intervals and compared with those of normal skin (control). A perfusion ratio was determined in each case according to the following formula: flap reading/(normal skin control reading X 100). Partial necrosis occurred in 4 patients, correlating with low fluorescein perfusion measurements. From our findings, it appears that a perfusion ratio of 15% or greater 10 minutes following injection will accurately predict tissue viability. No systemic reactions were observed in these patients. We believe that this minimally invasive technique should be of considerable assistance in the postoperative evaluation of flap viability.