title: Contrast harmonic ultrasound and indocyanine-green fluorescence video angiography for evaluation of dermal and subdermal microcirculation in free parascapular flaps.
abstract: OBJECTIVE
  Contrast harmonic ultrasound (CHI) with a linear transducer is a new diagnostic approach that allows dynamic and quantitative flow detection of tissue perfusion in microsurgery. The aim of the study was the evaluation of perfusion of the dermal and subdermal layers of microvascular tissue transplants with CHI in comparison to ICG-fluorescence angiography.
  
  
  METHODS
  In a prospective clinical study Indocyanine-Green Fluorescence Video Angiography and Contrast Enhanced High Resolution Ultrasound (5-10 MHz; linear transducer; Logiq 9; GE) were used for evaluation of the microcirculation in 10 transplanted free parascapular flaps. Two regions were analysed, the centre of the flap and the region of the anastomosis. The perfusion patterns of both methods were compared.
  
  
  RESULTS
  The perfusion indexes measured by ICG-fluorescence angiography correlated very precisely in all patients with the quantitative perfusion curves of contrast-enhanced US with CHI. Two flaps with slow filling and low dye intensity showed low contrast enhancement in CHI with modified perfusion curves with slow increase. In two cases a reduced perfusion and filling were found. There were no statistical differences between the two diagnostic methods (p>0.01).
  
  
  CONCLUSIONS
  CHI improves US detections of dermal and subdermal microcirculation in comparison to ICG fluorescence angiography. CHI is a new diagnostic method for postoperative monitoring of free flaps.
authors.affiliation: Institute of Trauma, Plastic and Reconstructive Surgery, University Hospital Regensburg, Germany. lukas.prantl@klinik.uni-regensburg.de
authors.forename: L
authors.initials: L
authors.lastname: Prantl
authors.forename: St
authors.initials: S
authors.lastname: Schmitt
authors.forename: S
authors.initials: S
authors.lastname: Geis
authors.forename: T Y
authors.initials: TY
authors.lastname: Tsui
authors.forename: P
authors.initials: P
authors.lastname: Lamby
authors.forename: M
authors.initials: M
authors.lastname: Nerlich
authors.forename: R
authors.initials: R
authors.lastname: Kubale
authors.forename: N
authors.initials: N
authors.lastname: Zorger
authors.forename: T
authors.initials: T
authors.lastname: Herold
authors.forename: S
authors.initials: S
authors.lastname: Feuerbach
authors.forename: E M
authors.initials: EM
authors.lastname: Jung
mesh_terms: D000328:Adult; D000714:Anastomosis, Surgical; D000792:Angiography / Q000295:instrumentation* / Q000379:methods*; D003287:Contrast Media / Q000494:pharmacology*; D005456:Fluorescent Dyes / Q000494:pharmacology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods; D007208:Indocyanine Green / Q000494:pharmacology*; D008833:Microcirculation / Q000000981:diagnostic imaging* / Q000473:pathology*; D018715:Microscopy, Video / Q000379:methods; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology; D010477:Perfusion; D012867:Skin / Q000098:blood supply*; D013524:Surgical Flaps; D014465:Ultrasonics; D014463:Ultrasonography / Q000295:instrumentation* / Q000379:methods
chemical_list: D003287:Contrast Media; D005456:Fluorescent Dyes; D007208:Indocyanine Green