title: Comparing quantitative values of two generations of laser-assisted indocyanine green dye angiography systems: can we predict necrosis?
abstract: OBJECTIVE
  Several devices exist today to assist the intraoperative determination of skin flap perfusion. Laser-Assisted Indocyanine Green Dye Angiography (LAICGA) has been shown to accurately predict mastectomy skin flap necrosis using quantitative perfusion values. The laser properties of the latest LAICGA device (SPY Elite) differ significantly from its predecessor system (SPY 2001), preventing direct translation of previous published data. The purpose of this study was to establish a mathematical relationship of perfusion values between these 2 devices.
  
  
  METHODS
  Breast reconstruction patients were prospectively enrolled into a clinical trial where skin flap evaluation and excision was based on quantitative SPY Q values previously established in the literature. Initial study patients underwent mastectomy skin flap evaluation using both SPY systems simultaneously. Absolute perfusion unit (APU) values at identical locations on the breast were then compared graphically.
  
  
  RESULTS
  210 data points were identified on the same patients (n = 4) using both SPY systems. A linear relationship (y = 2.9883x + 12.726) was identified with a high level or correlation (R(2) = 0.744). Previously published values using SPY 2001 (APU 3.7) provided a value of 23.8 APU on the SPY Elite. In addition, postoperative necrosis in these patients correlated to regions of skin identified with the SPY Elite with APU less than 23.8.
  
  
  CONCLUSIONS
  Intraoperative comparison of LAICGA systems has provided direct correlation of perfusion values predictive of necrosis that were previously established in the literature. An APU value of 3.7 from the SPY 2001 correlates to a SPY Elite APU value of 23.8.
authors.affiliation: Division of Plastic, Maxillofacial, & Oral Surgery, Duke University Medical Center, Durham, NC.
authors.forename: Brett T
authors.initials: BT
authors.lastname: Phillips
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA.
authors.forename: Mitchell S
authors.initials: MS
authors.lastname: Fourman
authors.affiliation: Stony Brook University School of Medicine, Stony Brook, NY.
authors.forename: Andrew
authors.initials: A
authors.lastname: Rivara
authors.affiliation: Stony Brook University Medical Center, Division of Plastic and Reconstructive Surgery.
authors.forename: Alexander B
authors.initials: AB
authors.lastname: Dagum
authors.affiliation: Stony Brook University Medical Center, Division of Plastic and Reconstructive Surgery.
authors.forename: Tara L
authors.initials: TL
authors.lastname: Huston
authors.affiliation: Stony Brook University Medical Center, Division of Plastic and Reconstructive Surgery.
authors.forename: Jason C
authors.initials: JC
authors.lastname: Ganz
authors.affiliation: Stony Brook University Medical Center, Division of Plastic and Reconstructive Surgery.
authors.forename: Duc T
authors.initials: DT
authors.lastname: Bui
authors.affiliation: Stony Brook University Medical Center, Division of Plastic and Reconstructive Surgery.
authors.forename: Sami U
authors.initials: SU
authors.lastname: Khan
keywords: SPY; breast reconstruction; indocyanine green dye; mastectomy skin flap necrosis; quantitative perfusion values