title: Effect of isovolemic, isothermic hemodialysis on cerebral perfusion and vascular stiffness using contrast computed tomography and pulse wave velocity.
abstract: BACKGROUND
  Patients undergoing hemodialysis treatment have a six-fold increased risk for stroke relative to the general population. However, the effect of hemodialysis on cerebral blood flow is poorly studied and confounding factors like blood pressure and ultrafiltration as well as temperature changes have rarely been accounted for. The aim of our study was to use state-of-the-art technology to evaluate the effect of a single dialysis session on cerebral perfusion as well as on vascular stiffness.
  
  
  METHODS
  Chronic hemodialysis patients (7 male/3 female, mean age 58 years) were recruited. Cerebral blood flow and arterial pulse wave velocity were measured before and immediately after a hemodialysis session. To exclude effects of volume changes we kept ultrafiltration to a minimum, allowing no change in body weight. Isothermic conditions were maintained by using the GENIUS single-pass batch-dialysis system with a high-flux polysulfone dialyser. Cerebral blood flow was measured by contrast-enhanced computed tomography. Pulse wave velocity was measured using the SphygmoCor (AtCor Medical, USA) device by a single operator.
  
  
  RESULTS
  This study shows for the first time that isovolemic, isothermic hemodialysis neither affected blood pressure or heart rate, nor total or regional cerebral perfusion. There was also no change in pulse wave velocity.
  
  
  CONCLUSIONS
  Mechanisms other than the dialysis procedure itself might be causative for the high incidence of ischemic strokes in this patient population. Moreover, the sole removal of uremic toxins does not lead to short-term effects on vascular stiffness, underlying the importance of volume control in this patient population.
authors: Department of Nephrology and Hypertension, Medical School Hannover, Hannover, Germany.
authors: Ansgar
authors: A
authors: Reising
authors: Saskia
authors: S
authors: Sambale
authors: Frank
authors: F
authors: Donnerstag
authors: Julius J
authors: JJ
authors: Schmidt
authors: Carsten
authors: C
authors: Hafer
authors: Bernhard M W
authors: BM
authors: Schmidt
authors: Jan T
authors: JT
authors: Kielstein
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D063177:Pulse Wave Analysis; D006435:Renal Dialysis / Q000009:adverse effects*; D014057:Tomography, X-Ray Computed; D059289:Vascular Stiffness / Q000502:physiology