title: Features of lymphatic dysfunction in compressed skin tissues - Implications in pressure ulcer aetiology.
abstract: OBJECTIVE
  Impaired lymph formation and clearance has previously been proposed as a contributory factor in the development of pressure ulcers. The present study has been designed to trial fluorescence lymphangiography for establishing how lymphatic function is altered under a clinically relevant form of mechanical loading.
  
  
  METHODS
  Lymph formation and clearance was traced in both forearms by an intradermal injection of indocyanine green (ICG) (50 μl, 0.05%w/v), imaged using a commercial near-infrared fluorescence imaging unit (Fluobeam(®) 800). External uniaxial loading equivalent to a pressure of 60 mmHg was applied for 45 min in one arm using a custom-built indenter.
  
  
  RESULTS
  Loading was associated with a decreased frequency of normal directional drainage (DD) of ICG within delineated vessels, both immediately after loading and 45 min thereafter. Loading was also associated with non-directional drainage (NDD) of ICG within the interstitium. Signal intensity within NDD was often greatest at areas of stress concentration, producing a 'halo pattern', corresponding to the rounded edges of the indenter.
  
  
  CONCLUSIONS
  These results suggest that loading skin with a clinically relevant magnitude of pressure alters both lymph formation and clearance. Further work to quantify impaired clearance under mechanical loading could provide valuable insight into their involvement in the development of pressure ulcers.
authors.affiliation: Faculty of Health Sciences, University of Southampton, Southampton, UK. Electronic address: rg3v07@soton.ac.uk.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Gray
authors.affiliation: Faculty of Health Sciences, University of Southampton, Southampton, UK.
authors.forename: David
authors.initials: D
authors.lastname: Voegeli
authors.affiliation: Faculty of Health Sciences, University of Southampton, Southampton, UK.
authors.forename: Dan L
authors.initials: DL
authors.lastname: Bader
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007208:Indocyanine Green; D008208:Lymphatic System / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011312:Pressure; D003668:Pressure Ulcer / Q000209:etiology*; D012867:Skin / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D007208:Indocyanine Green
keywords: Dermal lymphatics; Indocyanine green; Lymph stasis; Pressure ulcer; Uniaxial pressure