title: How to assess microvascular structure in humans.
abstract: Structural alterations of subcutaneous small resistance arteries, as indicated by an increased media to lumen ratio, are frequently present in hypertensive and/or diabetic patients. However, the evaluation of microvascular structure is not an easy task. Among the methods that may be applied to humans, plethysmographic evaluation of small arteries and wire or pressure micromyography were extensively used in the last decades. Media to lumen ratio of small arteries evaluated by micromyography was demonstrated to possess a strong prognostic significance; however, its extensive evaluation is limited by the invasiveness of the assessment, since a biopsy of subcutaneous fat is needed. Non-invasive approaches were then proposed, including capillaroscopy, which provides information about microvascular rarefaction. Recently, the interest of investigators has focused on the retinal microvascular bed. In particular, a non-invasive measurement of wall thickness to internal lumen ratio of retinal arterioles using scanning laser Doppler flowmetry has been recently introduced. Preliminary data suggest a fairly good agreement between this approach and micromyographic measurements, generally considered the gold standard approach. Therefore, the evaluation of microvascular structure is progressively moving from bench to bedside, and it could represent, in the immediate future, an evaluation to be performed in all hypertensive patients, in order to obtain a better stratification of cardiovascular risk.
authors.affiliation: Clinica Medica, Department of Medical and Surgical Sciences, University of Brescia, Brescia, Italy. rizzoni@med.unibs.it
authors.forename: Damiano
authors.initials: D
authors.lastname: Rizzoni
authors.forename: Christian
authors.initials: C
authors.lastname: Aalkjaer
authors.forename: Carolina
authors.initials: C
authors.lastname: De Ciuceis
authors.forename: Enzo
authors.initials: E
authors.lastname: Porteri
authors.forename: Claudia
authors.initials: C
authors.lastname: Rossini
authors.forename: Claudia Agabiti
authors.initials: CA
authors.lastname: Rosei
authors.forename: Annamaria
authors.initials: A
authors.lastname: Sarkar
authors.forename: Enrico Agabiti
authors.initials: EA
authors.lastname: Rosei
mesh_terms: D001160:Arterioles / Q000473:pathology* / Q000503:physiopathology; D005542:Forearm / Q000098:blood supply; D006801:Humans; D006973:Hypertension / Q000150:complications; D017078:Laser-Doppler Flowmetry; D008833:Microcirculation; D009213:Myography; D010991:Plethysmography; D012171:Retinal Vessels / Q000473:pathology; D017540:Tunica Media / Q000473:pathology*; D014655:Vascular Resistance