title: Quantitative assessment of bone microvascularization after osteocutaneous flap transplantation using contrast-enhanced ultrasound (CEUS).
abstract: BACKGROUND
  Extensive wound defects frequently have to be covered by free flap transplantation. A monitoring device for measuring capillary level perfusion of bone is currently not available.
  
  
  OBJECTIVE
  The aim of the study was to detect complications after osteocutaneous flap transplantation using contrast-enhanced ultrasound (CEUS). Additionally quantitative analysis was performed by special perfusion software (QONTRAST®; Bracco, Italy).
  
  
  METHODS
  22 patients were examined after osteocutaneous flap transplantation during the first 72 h after operation. CEUS was performed with a linear transducer (6-9 MHz, LOGIQ E9/GE) after bolus injections of 2.4 ml ultrasound contrast agent (SonoVue®; Bracco, Italy). The osseous perfusion and soft tissue perfusion were analyzed separately and quantitative perfusion analysis was performed. Five patients had to undergo reoperation due to compromised flap microvascularization.
  
  
  RESULTS
  In all 5 complications reduced osseous and soft tissue perfusion was seen using CEUS. Additionally using the perfusion parameters TTP (time to PEAK), RBV (regional blood volume), RBF (regional blood flow) und MTT (mean transit time), significantly lower soft tissue and osseous perfusion was detected.
  
  
  CONCLUSIONS
  CEUS seems to be capable of detecting vascular disturbances and of assessing microvascularization of the osseous component after osteocutaneous flap transplantation.
authors.affiliation: Center of Plastic-, Hand- and Reconstructive Surgery, University Hospital and Caritas Hospital St. Josef Regensburg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Geis
authors.forename: L
authors.initials: L
authors.lastname: Prantl
authors.forename: S
authors.initials: S
authors.lastname: Mueller
authors.forename: M
authors.initials: M
authors.lastname: Gosau
authors.forename: P
authors.initials: P
authors.lastname: Lamby
authors.forename: E M
authors.initials: EM
authors.lastname: Jung
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016025:Bone Transplantation / Q000379:methods*; D001842:Bone and Bones / Q000098:blood supply*; D002196:Capillaries / Q000000981:diagnostic imaging / Q000473:pathology; D003287:Contrast Media; D005260:Female; D058752:Free Tissue Flaps / Q000098:blood supply* / Q000601:surgery; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007511:Ischemia / Q000000981:diagnostic imaging / Q000601:surgery; D008297:Male; D008833:Microcirculation / Q000502:physiology*; D008875:Middle Aged; D010743:Phospholipids; D011183:Postoperative Complications / Q000000981:diagnostic imaging* / Q000601:surgery; D012086:Reoperation; D018461:Soft Tissue Infections / Q000000981:diagnostic imaging* / Q000601:surgery*; D017695:Soft Tissue Injuries / Q000000981:diagnostic imaging* / Q000601:surgery*; D012983:Soft Tissue Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery*; D012984:Software; D013459:Sulfur Hexafluoride; D014463:Ultrasonography / Q000379:methods*
chemical_list: D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride