title: Endoscopic measurements of free-flap perfusion in the head and neck region using red-excited Indocyanine Green: preliminary results.
abstract: BACKGROUND
  Free-tissue transfer has become a standard procedure for reconstructive surgery in the head and neck area. Flap failures are relatively rare (<or=5%), and a high percentage can be salvaged if detected early. Indocyanine Green (ICG) angiography might be able to improve the detection of flap malperfusion at an early stage.
  
  
  METHODS
  So far, 11 patients with free-flap reconstructions of the upper aerodigestive tract (UADT) have participated in this study. Each participant underwent three endoscopic ICG angiographies (24h intra-operatively and 72h postoperatively). The data obtained were evaluated online as well as offline on a personal computer (PC), and the results compared to the clinical outcome.
  
  
  RESULTS
  There were no partial or complete flap losses. One flap was successfully salvaged following initial arterial kinking with impeded perfusion. The ICG fluorescence angiography was tolerated well in all patients. The free flaps showed a delayed yet equal ICG fluorescence as compared to the surrounding tissue. The timing and slope of fluorescence build-up were dependent on circulatory factors. The relative fluorescence maxima of flap versus surrounding were 33% in the initially failing flap and >or=64% for all other examinations.
  
  
  CONCLUSIONS
  It was possible to prove the feasibility of endoscopic ICG fluorescence angiography in patients undergoing free-flap transfer to the UADT. The method provides instant information about the perfusion state of the tissue and is easily performed without greater patient discomfort or risk of side effects. Due to the endoscopic approach, the method seems highly promising for this indication and merits further evaluation.
authors.affiliation: Department of Otorhinolaryngology, Head & Neck Surgery, Ludwig Maximilian University, Grosshadern Medical Campus, Marchioninistr 15, D-81377 Munich, Germany. christian.betz@med.uni-muenchen.de
authors.forename: C S
authors.initials: CS
authors.lastname: Betz
authors.forename: S
authors.initials: S
authors.lastname: Zhorzel
authors.forename: H
authors.initials: H
authors.lastname: Schachenmayr
authors.forename: H
authors.initials: H
authors.lastname: Stepp
authors.forename: M
authors.initials: M
authors.lastname: Havel
authors.forename: V
authors.initials: V
authors.lastname: Siedek
authors.forename: A
authors.initials: A
authors.lastname: Leunig
authors.forename: C
authors.initials: C
authors.lastname: Matthias
authors.forename: C
authors.initials: C
authors.lastname: Hopper
authors.forename: U
authors.initials: U
authors.lastname: Harreus
mesh_terms: D000368:Aged; D004396:Coloring Agents; D004724:Endoscopy / Q000379:methods; D005240:Feasibility Studies; D005260:Female; D005451:Fluorescein Angiography / Q000379:methods; D006084:Graft Rejection / Q000175:diagnosis; D006258:Head and Neck Neoplasms / Q000601:surgery*; D006801:Humans; D007208:Indocyanine Green; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D011182:Postoperative Care / Q000379:methods; D019651:Plastic Surgery Procedures / Q000379:methods*; D013524:Surgical Flaps / Q000098:blood supply*
chemical_list: D004396:Coloring Agents; D007208:Indocyanine Green