title: Transmitted cardiac pulsations as an indicator of transjugular intrahepatic portosystemic shunt function: initial observations.
abstract: OBJECTIVE
  To determine if cardiac pulsations are visible and quantifiable on spectral waveforms during Doppler ultrasonographic (US) evaluation of transjugular intrahepatic portosystemic shunts (TIPS), and if so, whether their magnitude declines with shunt dysfunction.
  
  
  METHODS
  Baseline and pre-revision US images obtained in 15 patients with venographically confirmed TIPS malfunction were retrospectively examined for spectral waveform pulsation. Cardiac pulsatility was quantified by using the venous pulsatility index (VPI), the venous equivalent of resistive index. VPIs were obtained at four locations from the main portal vein to the stent-hepatic venous junction. Baseline and follow-up examination results in 11 patients with functional TIPS acted as controls and were evaluated similarly. Baseline and follow-up mean VPIs at all four locations were compared for both sets of patients by using the Newman-Keuls pairwise multiple sample comparison test. The chi(2) test was used to determine if a VPI threshold that would result in an acceptable sensitivity and specificity for shunt dysfunction existed.
  
  
  RESULTS
  One hundred twenty mean VPIs were obtained in the study group, and 88 mean VPIs were obtained in the control group. Pre-revision VPIs at each location were significantly lower (P <.01) than all baseline values and than the follow-up values in the control group. A VPI less than 0.16 was 94% sensitive and 87% specific for shunt dysfunction.
  
  
  CONCLUSIONS
  The VPI, a quantitative measure of cardiac pulsation obtained with Doppler US, may be a useful parameter for assessing TIPS function.
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Ave, Boston, MA 02215, USA. rsheiman@caregroup.harvard.edu
authors.forename: Robert G
authors.initials: RG
authors.lastname: Sheiman
authors.forename: Thomas
authors.initials: T
authors.lastname: Vrachliotis
authors.forename: David P
authors.initials: DP
authors.lastname: Brophy
authors.forename: Bernard J
authors.initials: BJ
authors.lastname: Ransil
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006321:Heart / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D019168:Portasystemic Shunt, Transjugular Intrahepatic; D011674:Pulse; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D018608:Ultrasonography, Doppler