title: Indocyanine green fluorescence angiography for free flap monitoring: A pilot study.
abstract: OBJECTIVE
  We evaluated the feasibility and the tolerance of repeated fluorescent indocyanine green angiography in free flap monitoring, and determined the intraoperative predictive values of flap vitality.
  
  
  BACKGROUND
  The free flap failure rate has been significantly reduced, but free flap loss still occurs and remains a costly disaster. Repeated clinical examinations are commonly used for flap monitoring, but they can be unreliable because of their subjectivity. Laser-induced fluorescence of indocyanine green is a new method for assessing tissue perfusion.
  
  
  METHODS
  20 patients undergoing microsurgical reconstruction were monitored by indocyanine green fluorescence angiography, intraoperatively, and during 4 days after surgery, with 18 injections. Monitoring was made by clinical examination, and then compared to angiographic findings.
  
  
  RESULTS
  The vascular complication rate was 15% (3/20) with 2 cases of venous thrombosis and one case of partial necrosis of the flap skin paddle. Both cases of venous thrombosis were salvaged by secondary surgery. There was no total flap loss. ICG angiography allowed detecting each intra and postoperative complication, earlier than clinical examination. The mean per-operative intensity of fluorescence was significantly lower in flaps with vascular complications (23.8 GL/ms; p = 0.008). The postoperative slope (p = 0.02) and amplitude (p = 0.03) of the fluorescent signal were both significantly lower than for uncomplicated flaps, before surgical revision. These 2 parameters came back to normal values after secondary surgery. There was no adverse effect of ICG despite the repeated injections.
  
  
  CONCLUSIONS
  ICG angiography is a feasible and safe technique for the detection of free flap vascular complications.
authors.affiliation: Plastic and Maxillofacial Surgery Department, Hôpital A Michallon, BP217, 38043 Grenoble Cedex, France.
authors.forename: Marine
authors.initials: M
authors.lastname: Hitier
authors.affiliation: Centre d'investigation clinique, Hôpital A Michallon, BP217, 38043 Grenoble Cedex, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Cracowski
authors.affiliation: Plastic and Maxillofacial Surgery Department, Hôpital A Michallon, BP217, 38043 Grenoble Cedex, France.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Hamou
authors.affiliation: ENT Department, Hôpital A Michallon, BP217, 38043 Grenoble Cedex, France; INSERM-UJF U823 Team 5, Institut Albert Bonniot, 38706 Grenoble Cedex, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Righini
authors.affiliation: INSERM-UJF U823 Team 5, Institut Albert Bonniot, 38706 Grenoble Cedex, France; Maxillofacial Surgery Department, Centre hospitalier Annecy Genevois, 1 avenue de l'hôpital, 74370 Epagny Metz-Tessy, France. Electronic address: gbettega@ch-annecygenevois.fr.
authors.forename: Georges
authors.initials: G
authors.lastname: Bettega
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005451:Fluorescein Angiography / Q000379:methods*; D058752:Free Tissue Flaps / Q000009:adverse effects / Q000098:blood supply; D006801:Humans; D007208:Indocyanine Green / Q000627:therapeutic use*; D008297:Male; D063175:Mandibular Reconstruction / Q000379:methods; D008875:Middle Aged; D010865:Pilot Projects; D019651:Plastic Surgery Procedures / Q000379:methods; D016896:Treatment Outcome
chemical_list: D007208:Indocyanine Green
keywords: Fluorescence angiography; Free flaps; Indocyanine green