title: Microvascular blood is distributed more to venules than to arterioles in patients with Buerger's disease. Observation of bulbar conjunctiva by intravital microscope system.
abstract: BACKGROUND
  It has been a matter of controversy whether abnormalities of organs other than extremities may be a clinical manifestation of Buerger's disease (thromboangiitis obliterans; TAO). In the present investigation, our aim was to quantitatively characterise the configuration of microvascular networks in bulbar conjunctiva, which is not affected apparently, in patients with thromboangiitis obliterans.
  
  
  METHODS
  Nine men with thromboangiitis obliterans attended our hospital and nine male volunteers as normal controls were enrolled in this study. We observed and analysed the configuration of the network of a bulbar conjunctiva by use of intravital microscope system with computer assisted image processing functions. Microvessel density was defined as a summation of vessel length in a ROI area and tortuosity was evaluated by a ratio of vessel length to direct distance of both terminals.
  
  
  RESULTS
  In the microcirculation of bulbar conjunctiva in thromboangiitis obliterans, arteriole diameter was significantly decreased and density of venules was significantly increased. Increased venular density was mainly explained by increased tortuosity of venules.
  
  
  CONCLUSIONS
  Consequently, microvascular blood was distributed more to venules than to arterioles in patients with thromboangiitis obliterans. Venule/arteriole ratios of diameter, tortuosity and microvessel density may be useful parameters to characterize the configuration of microvascular networks in thromboangiitis obliterans.
authors.affiliation: Department of Internal Medicine, National Cardiovascular Center, Suita, Japan. homma-s@md.tsukuba.ac.jp
authors.forename: S
authors.initials: S
authors.lastname: Homma
authors.forename: N
authors.initials: N
authors.lastname: Tsushima
authors.forename: M
authors.initials: M
authors.lastname: Minamiyama
authors.forename: T
authors.initials: T
authors.lastname: Hayashi
authors.forename: H
authors.initials: H
authors.lastname: Matsuo
mesh_terms: D000328:Adult; D001160:Arterioles; D016022:Case-Control Studies; D003228:Conjunctiva / Q000098:blood supply*; D006801:Humans; D008297:Male; D008833:Microcirculation / Q000503:physiopathology; D018715:Microscopy, Video; D013919:Thromboangiitis Obliterans / Q000503:physiopathology*; D014699:Venules