102. Validating The Use of SPY-PHI To Study Flap Perfusion on Cadaveric Models

PURPOSE: Fluorescence imaging has become a widely used tool in reconstructive surgery to assess flap perfusion. More recently, the technology has been used in the laboratory to study the perfusion of flaps in cadaveric models. Traditionally, methylene blue has been used in the lab for this purpose; however, fluorescence imaging can provide higher quality, quantitative images to study angiosomes and flap perfusion. The purpose of our study was to determine the reliability of image production using a flap with a single, consistent perforator and compare this to current knowledge to determine the clinical relevance of using this technology in the lab on cadaveric models. We also wished to establish a reproducible protocol for the injections that can be repeated in other studies. METHODS: Transverse skin markings were made from the acromion directly medially the midline, from the acromion to the posterior superior iliac spine, posterior superior iliac spine medially to the midline, and along the midline to complete a rectangular skin flap composing half of the back skin. The skin was elevated on the transverse branch of the circumflex scapular vessels arising within the triangular space. The pedicle was dissected out and transected. We then injected 5cc of reconstituted indocyanine green into the pedicle with a 24g angiocath followed by 30cc of saline. The SPY-PHI (Stryker, Kalamazoo, MI) was then used on a quantitative perfusion setting to take perfusion images 30 minutes after injection. Images were analyzed on Canfield Mirror (Parsippany, New Jersey). Maximum length, width, and area were calculated based on the images. T test was used to compare the average area of flap perfusion seen on the SPY-Phi to that of published literature RESULTS: The average lengths, widths, and area of the perfused portions of the skin flaps were 18.24cm, 23.25cm, and 281.5cm. The standard deviation of the total area was 38.4cm CONCLUSION: The SPY-PHI appears to demonstrate reliable angiosomes in the cadaver model. This is a useful tool to study flap perfusion on cadavers in the laboratory.