title: Bronchoscopic Indocyanine Green Fluorescence Imaging of the Anastomotic Perfusion After Tracheal Surgery.
abstract: BACKGROUND
  Anastomotic failure is a rare but severe complication after airway surgery. A sufficient blood supply is crucial for the healing of the anastomosis. Currently, judging the appearance of the mucosa by conventional bronchoscopy is the only available technique to monitor the anastomosis. Near-infrared imaging using indocyanine green (ICG) as an intravasal fluorescent can be used to directly assess tissue perfusion. For technical reasons, bronchoscopic ICG angiography to evaluate blood supply of airway anastomosis was unavailable in the past. We sought to investigate the technical feasibility of ICG perfusion using a newly developed bronchoscopy unit with an integrated near-infrared filter to monitor perfusion during the healing of tracheal anastomosis.
  
  
  METHODS
  Twelve patients who underwent elective airway surgery were included in this prospective, single-center feasibility study. The ICG was administered intravenously at 0.2 mg/kg body weight at three timepoints: at the end of surgery; 3 to 5 days postoperatively; and 2 months postoperatively. A custom-made bronchoscopy unit (Karl Storz, Tuttlingen, Germany) was used to assess the anastomosis with white light and additionally with near-infrared light to monitor the distribution and intensity of the fluorescence signal.
  
  
  RESULTS
  A total of 32 ICG fluorescence bronchoscopies were performed in our study cohort. In all measurements, a sufficient fluorescence signal was detected. A lack of perfusion was detected in all patients confined to the anastomotic suture line immediately after the operation. This malperfusion resolved gradually after 3 to 5 days and disappeared completely after 2 months. No anastomotic complication developed in our series of patients during follow-up (median 7 months).
  
  
  CONCLUSIONS
  To the best of our knowledge, this is the first report on ICG fluorescence bronchoscopy in the literature. It is an easy and effective method to evaluate the perfusion at the tracheal anastomosis. In the future, it might contribute to an early detection of anastomotic failure and reduce morbidity and mortality after airway surgery.
authors.affiliation: Division of Thoracic Surgery, Medical University of Vienna, Vienna, Austria; Christian Doppler Laboratory for Cardiac and Thoracic Diagnosis and Regeneration, Medical University of Vienna, Vienna, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Schweiger
authors.affiliation: Division of Thoracic Surgery, Medical University of Vienna, Vienna, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schwarz
authors.affiliation: Division of Thoracic Surgery, Medical University of Vienna, Vienna, Austria; Christian Doppler Laboratory for Cardiac and Thoracic Diagnosis and Regeneration, Medical University of Vienna, Vienna, Austria.
authors.forename: Denise
authors.initials: D
authors.lastname: Traxler
authors.affiliation: Department of Neurosurgery, Medical University of Vienna, Vienna, Austria.
authors.forename: Philippe
authors.initials: P
authors.lastname: Dodier
authors.affiliation: Division of Thoracic Surgery, Medical University of Vienna, Vienna, Austria.
authors.forename: Clemens
authors.initials: C
authors.lastname: Aigner
authors.affiliation: Division of Thoracic Surgery, Medical University of Vienna, Vienna, Austria.
authors.forename: György
authors.initials: G
authors.lastname: Lang
authors.affiliation: Division of Thoracic Surgery, Medical University of Vienna, Vienna, Austria.
authors.forename: Walter
authors.initials: W
authors.lastname: Klepetko
authors.affiliation: Division of Thoracic Surgery, Medical University of Vienna, Vienna, Austria. Electronic address: konrad.hoetzenecker@meduniwien.ac.at.
authors.forename: Konrad
authors.initials: K
authors.lastname: Hoetzenecker
mesh_terms: D000368:Aged; D000714:Anastomosis, Surgical / Q000009:adverse effects*; D001999:Bronchoscopy / Q000379:methods*; D005260:Female; D005453:Fluorescence; D006801:Humans; D007208:Indocyanine Green; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D014132:Trachea / Q000098:blood supply / Q000000981:diagnostic imaging / Q000601:surgery*
chemical_list: D007208:Indocyanine Green