title: Determination of brachial artery stiffness prior to vascular access creation: reproducibility of pulse wave velocity assessment.
abstract: BACKGROUND
  Despite routine ultrasound mapping of upper extremity arteries and veins, early thrombosis and nonmaturation remain frequent complications following vascular access (VA) surgery. Besides vascular diameters, brachial artery stiffness is assumed to play an important role; however, reproducibility of measurements has never been established. The purpose of this study was to determine within-session and between-session variabilities of pulse wave velocity (PWV) assessment by using ultrasonography and blood pressure registration.
  
  
  METHODS
  Beat-to-beat changes in brachial artery diameter and pressure were obtained in 21 subjects in measurement sessions on Day 1 and Day 3. Each session consisted of three acquisitions. For each acquisition, systolic and diastolic diameter and pressure were determined and used for calculation of brachial artery PWV. Within-session variability of diameter and pressure, as well as the estimated PWV, was expressed using the intraclass correlation coefficient with corresponding coefficient of variation (CoV). Between-session variability was reported using Bland-Altman analysis in combination with CoV analysis.
  
  
  RESULTS
  Significant agreement (P < 0.001) was obtained for all diameter and pressure measurements obtained on Day 1 and Day 3. Within-session CoV of pulse pressure, diastolic diameter and distension were 7.0, 1.6 and 18.3%, respectively. Subsequent estimation of local PWV resulted in a CoV of 10.6%. Between-session CoV was 15.1, 3.8 and 18.9% for pulse pressure, diastolic diameter and distension, respectively. For PWV estimation, this resulted in a CoV of 13.5%.
  
  
  CONCLUSIONS
  Diameter and pressure can be recorded accurately over the cardiac cycle, and calculations of distensibility, pulse pressure and PWV show a slight to moderate degree of variation. Larger studies elaborating on interindividual differences need to determine the clinical efficacy of PWV measurements prior to VA creation.
authors.affiliation: Department of Surgery, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Aron S
authors.initials: AS
authors.lastname: Bode
authors.forename: Jaap
authors.initials: J
authors.lastname: Leermakers
authors.forename: J Wilco
authors.initials: JW
authors.lastname: Kroon
authors.forename: Peter
authors.initials: P
authors.lastname: Brands
authors.forename: R Nils
authors.initials: RN
authors.lastname: Planken
authors.forename: Jan H M
authors.initials: JH
authors.lastname: Tordoir
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D001794:Blood Pressure; D001795:Blood Pressure Determination; D001916:Brachial Artery / Q000473:pathology*; D002320:Cardiovascular Physiological Phenomena; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate; D006801:Humans; D007676:Kidney Failure, Chronic / Q000473:pathology*; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D011673:Pulsatile Flow; D015203:Reproducibility of Results; D012307:Risk Factors; D014655:Vascular Resistance; D055815:Young Adult