title: Assessment of microcirculation of the skin using Tissue Viability Imaging: A promising technique for detecting venous stasis in the skin.
abstract: BACKGROUND
  Venous occlusion in the skin is difficult to detect by existing measurement techniques. Our aim was to find out whether Tissue Viability Imaging (TiVi) was better at detecting venous occlusion by comparing it with results of laser Doppler flowmetry (LDF) during graded arterial and venous stasis in human forearm skin.
  
  
  METHODS
  Arterial and venous occlusions were simulated in 10 healthy volunteers by inflating a blood pressure cuff around the upper right arm. Changes in the concentration of red blood cells (RBC) were measured using TiVi, while skin perfusion and concentration of moving red blood cells (CMBC) were measured using static indices of LDF during exsanguination and subsequent arterial occlusion, postocclusive reactive hyperaemia, and graded increasing and decreasing venous stasis.
  
  
  RESULTS
  During arterial occlusion there was a significant reduction in the mean concentration of RBC from baseline, as well as in perfusion and CMBC (p<0.008). Venous occlusion resulted in a significant 28% increase in the concentration of RBC (p=0.002), but no significant change in perfusion (mean change -14%) while CMBC decreased significantly by 24% (p=0.02). With stepwise increasing occlusion pressures there was a significant rise in the TiVi index and reduction in perfusion (p=0.008), while the reverse was seen when venous flow was gradually restored.
  
  
  CONCLUSIONS
  The concentration of RBC measured with TiVi changes rapidly and consistently during both total and partial arterial and venous occlusions, while the changes in perfusion, measured by LDF, were less consistent. This suggests that TiVi could be a more useful, non-invasive clinical monitoring tool for detecting venous stasis in the skin than LDF.
authors.affiliation: Department of Hand Surgery, Plastic Surgery and Burns, Linköping University, Linköping, Sweden; Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors.forename: Max
authors.initials: M
authors.lastname: Bergkvist
authors.affiliation: Allergy Center, Linköping University, Linköping, Sweden; Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors.forename: Joakim
authors.initials: J
authors.lastname: Henricson
authors.affiliation: Department of Hand Surgery, Plastic Surgery and Burns, Linköping University, Linköping, Sweden; Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Iredahl
authors.affiliation: Department of Radiation Physics, Linköping University, Linköping, Sweden; Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors.forename: Erik
authors.initials: E
authors.lastname: Tesselaar
authors.affiliation: Department of Hand Surgery, Plastic Surgery and Burns, Linköping University, Linköping, Sweden; Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors.forename: Folke
authors.initials: F
authors.lastname: Sjöberg
authors.affiliation: Department of Hand Surgery, Plastic Surgery and Burns, Linköping University, Linköping, Sweden. Electronic address: simon.farnebo@lio.se.
authors.forename: Simon
authors.initials: S
authors.lastname: Farnebo
mesh_terms: D000293:Adolescent; D000328:Adult; D001158:Arteries / Q000473:pathology*; D001783:Blood Flow Velocity; D002465:Cell Movement; D004912:Erythrocytes / Q000166:cytology; D005260:Female; D005542:Forearm; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation; D010477:Perfusion; D012039:Regional Blood Flow; D012867:Skin / Q000098:blood supply* / Q000473:pathology*; D014022:Tissue Survival; D014680:Veins / Q000473:pathology*; D055815:Young Adult
keywords: Arterial occlusion; Laser Doppler flowmetry; Post-occusive hyperaemia; Tissue viability imaging; Venous occlusion