title: Near-infrared spectroscopy and transcutaneous oxygen pressure during exercise to detect arterial ischemia at the buttock level: comparison with arteriography.
abstract: BACKGROUND
  Noninvasive tests are required to detect (in both male and female subjects and side by side) arteries toward the hypogastric circulation that are likely to present significant lesions as a cause of buttock claudication.
  
  
  METHODS
  We compared the accuracy of near-infrared spectroscopy (NIRS) and transcutaneous oxygen pressure (TCP o 2 ) on both buttocks during walking tests to detect lesions on the arteries toward the hypogastric circulation. NIRS was considered abnormal if recovery time to pre-exercise values was greater than 240 seconds for tissue oxygen saturation (absent data being coded 0), and TCP o 2 was coded abnormal if the minimal value of buttock changes minus chest changes was lower than -15 mm Hg. The study was conducted in a university hospital; there were 30 ambulatory patients with stage 2 claudication of the Fontaine classification.
  
  
  RESULTS
  Angiography showed 36 abnormal (stenosis > 75%) and 24 normal arterial axes toward the buttocks circulation. NIRS and TCP o 2 provided respectively 55% (range, 41.6% to 67.9%) and 82% (range, 69.6% to 90.5%) accuracy (95% confidence interval) to predict the presence of arteriographically proven lesions; P < .05.
  
  
  CONCLUSIONS
  Using available cut-off points proposed in the literature, NIRS showed a lower diagnostic accuracy than TCP o 2 for the prediction of lesions on the arterial tree to the hypogastric circulation. NIRS is a recent technique as compared with TCP o 2 , and its diagnostic accuracy might improve in the future. Currently, one should carefully weigh the advantages and limits of NIRS and TCP o 2 when a choice is to be made between them to monitor exercise-induced changes resulting from lower limb arterial disease at the proximal level.
authors.affiliation: Laboratoire d'Explorations Vasculaires, Centre Hospitalier Universitaire, Angers, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Bouyé
authors.forename: Vincent
authors.initials: V
authors.lastname: Jacquinandi
authors.forename: Jean
authors.initials: J
authors.lastname: Picquet
authors.forename: Francine
authors.initials: F
authors.lastname: Thouveny
authors.forename: Julien
authors.initials: J
authors.lastname: Liagre
authors.forename: Georges
authors.initials: G
authors.lastname: Leftheriotis
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Saumet
authors.forename: Pierre
authors.initials: P
authors.lastname: Abraham
mesh_terms: D000368:Aged; D000792:Angiography; D001785:Blood Gas Monitoring, Transcutaneous; D002081:Buttocks; D005080:Exercise Test; D005260:Female; D006801:Humans; D007511:Ischemia / Q000175:diagnosis*; D007866:Leg / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D010100:Oxygen; D012372:ROC Curve; D012680:Sensitivity and Specificity; D019265:Spectroscopy, Near-Infrared
chemical_list: D010100:Oxygen