title: Development of an Extracorporeal Perfusion Device for Small Animal Free Flaps.
abstract: BACKGROUND
  Extracorporeal perfusion (ECP) might prolong the vital storage capabilities of composite free flaps, potentially opening a wide range of clinical applications. Aim of the study was the development a validated low-cost extracorporeal perfusion model for further research in small animal free flaps.
  
  
  METHODS
  After establishing optimal perfusion settings, a specially designed extracorporeal perfusion system was evaluated during 8-hour perfusion of rat epigastric flaps followed by microvascular free flap transfer. Controls comprised sham-operation, ischemia and in vivo perfusion. Flaps and perfusate (diluted blood) were closely monitored by blood gas analysis, combined laser Doppler flowmetry and remission spectroscopy and Indocyanine-Green angiography. Evaluations were complemented by assessment of necrotic area and light microscopy at day 7.
  
  
  RESULTS
  ECP was established and maintained for 8 hours with constant potassium and pH levels. Subsequent flap transfer was successful. Notably, the rate of necrosis of extracorporeally perfused flaps (27%) was even lower than after in vivo perfusion (49%), although not statistically significant (P = 0,083). After sham-operation, only 6% of the total flap area became necrotic, while 8-hour ischemia led to total flap loss (98%). Angiographic and histological findings confirmed these observations.
  
  
  CONCLUSIONS
  Vital storage capabilities of microvascular flaps can be prolonged by temporary ECP. Our study provides important insights on the pathophysiological processes during extracorporeal tissue perfusion and provides a validated small animal perfusion model for further studies.
authors.affiliation: Department of Oral and Maxillo-Facial Surgery, Technische Universität München, Klinikum Rechts der Isar, München, Germany.
authors.forename: Andreas M
authors.initials: AM
authors.lastname: Fichter
authors.affiliation: Department of Oral and Maxillo-Facial Surgery, Technische Universität München, Klinikum Rechts der Isar, München, Germany.
authors.forename: Lucas M
authors.initials: LM
authors.lastname: Ritschl
authors.affiliation: Department of Oral and Maxillo-Facial Surgery, Technische Universität München, Klinikum Rechts der Isar, München, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Borgmann
authors.affiliation: Department of Oral and Maxillo-Facial Surgery, Technische Universität München, Klinikum Rechts der Isar, München, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Humbs
authors.affiliation: Institute for Clinical Chemistry and Pathobiochemistry, Technische Universität München, Klinikum Rechts der Isar, München, Germany.
authors.forename: Peter B
authors.initials: PB
authors.lastname: Luppa
authors.affiliation: Department of Oral and Maxillo-Facial Surgery, Technische Universität München, Klinikum Rechts der Isar, München, Germany.
authors.forename: Klaus-Dietrich
authors.initials: KD
authors.lastname: Wolff
authors.affiliation: Department of Oral and Maxillo-Facial Surgery, Technische Universität München, Klinikum Rechts der Isar, München, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Mücke
mesh_terms: D000818:Animals; D058752:Free Tissue Flaps / Q000473:pathology*; D007511:Ischemia / Q000473:pathology; D008297:Male; D023421:Models, Animal; D009336:Necrosis / Q000473:pathology; D051381:Rats; D046509:Tissue Culture Techniques
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