title: Face transplant perfusion assessment using near-infrared fluorescence imaging.
abstract: BACKGROUND
  Composite tissue allografts (CTAs) including partial face transplantation have been achieved clinically. However, risks of complications including tissue ischemia, rejection, and transplant failure are significant. Safe and effective techniques to assess perfusion are needed to decrease complications in composite tissue flaps. Near-infrared (NIR) fluorescence imaging has been previously shown to provide a real-time, intraoperative evaluation of perfusion. This study investigates the use of NIR imaging in partial face CTA harvest.
  
  
  METHODS
  We created hemifacial CTAs (n = 8) using an established porcine model. This included ear cartilage, nerve, lymphoid tissue, muscle, and skin with perfusion by the carotid artery and external jugular vein. We injected animals systemically with indocyanine green and obtained NIR fluorescence images simultaneously with color video. In addition, we assessed the elevated hemifacial flaps using standard of care (i.e., clinical examination and Doppler).
  
  
  RESULTS
  Flap design was facilitated by NIR imaging with localization of perforators to the hemifacial CTA flap. In particular, an arterial and venous phase could be clearly identified. We assessed perfusion of the flap by NIR fluorescence intensity after injection of indocyanine green. Sequential clamping of the artery and vein confirmed correlation of perfusion deficits with NIR imaging as well as with clinical examination and Doppler.
  
  
  CONCLUSIONS
  Evaluation and assessment of perfusion are important in facial transplantation. The results from our pilot study indicate that NIR imaging has the capability to assess perfusion of partial facial CTAs. This emergent technology shows promise in assessing tissue perfusion in a composite flap.
authors.affiliation: Division of Plastic Surgery, Department of Surgery, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.
authors.forename: John T
authors.initials: JT
authors.lastname: Nguyen
authors.forename: Yoshitomo
authors.initials: Y
authors.lastname: Ashitate
authors.forename: Ian A
authors.initials: IA
authors.lastname: Buchanan
authors.forename: Ahmed M S
authors.initials: AM
authors.lastname: Ibrahim
authors.forename: Sylvain
authors.initials: S
authors.lastname: Gioux
authors.forename: Priti P
authors.initials: PP
authors.lastname: Patel
authors.forename: John V
authors.initials: JV
authors.lastname: Frangioni
authors.forename: Bernard T
authors.initials: BT
authors.lastname: Lee
mesh_terms: D000818:Animals; D005145:Face / Q000098:blood supply*; D054445:Facial Transplantation; D005260:Female; D005451:Fluorescein Angiography; D011300:Preoperative Care; D013552:Swine