title: Improvement of nutritive perfusion after free tissue transfer by local heat shock-priming-induced preservation of capillary flowmotion.
abstract: BACKGROUND
  Capillary flowmotion protects pedicled flaps during critical perfusion conditions. However, free tissue transfer, causing ischemia-reperfusion and surgical trauma, have been shown to blunt these protective blood flow fluctuations. Because heat shock priming protects tissue after transfer, we herein studied whether heat shock protein expression is capable to preserve critical perfusion-induced capillary flowmotion in transferred composite flaps.
  
  
  METHODS
  In Sprague Dawley rats (n = 16), osteomyocutaneous flaps were subjected to critical perfusion after harvest and 1 h and 4 h after free transfer. In eight animals additional heat shock priming was induced 24 h before flap harvest. Microcirculation including capillary flowmotion was analyzed using intravital fluorescence microscopy.
  
  
  RESULTS
  After harvest, critical perfusion induced capillary flowmotion in skeletal muscle tissue of all flaps. By this, functional capillary density (FCD), an indicator of nutritive perfusion, was maintained not only in muscle but also in periosteum, subcutis, and skin. In contrast, 1 h after flap transfer muscle capillary flowmotion was completely abrogated, resulting in a significant decrease of FCD in all tissues. Heat shock-priming completely restored capillary flowmotion, and, by this, maintained tissue FCD.
  
  
  CONCLUSIONS
  The loss of muscle capillary flowmotion after free tissue transfer-associated ischemia-reperfusion can be prevented by heat shock-priming. This may represent the mechanism of protection by local heat application.
authors.affiliation: Institute for Clinical & Experimental Surgery, University of Saarland, Homburg/Saar, Germany. exmrue@med-rz.uni-sb.de
authors.forename: Martin
authors.initials: M
authors.lastname: Rücker
authors.forename: Bülent
authors.initials: B
authors.lastname: Kadirogullari
authors.forename: Brigitte
authors.initials: B
authors.lastname: Vollmar
authors.forename: Wolfgang J
authors.initials: WJ
authors.lastname: Spitzer
authors.forename: Michael D
authors.initials: MD
authors.lastname: Menger
mesh_terms: D000818:Animals; D002196:Capillaries / Q000502:physiology; D006358:Hot Temperature; D018482:Muscle, Skeletal / Q000098:blood supply; D010477:Perfusion; D051381:Rats; D017207:Rats, Sprague-Dawley; D012039:Regional Blood Flow; D013524:Surgical Flaps / Q000098:blood supply* / Q000294:innervation