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Reproducibility of WHVP Measurement

Reproducibility of WHVP Measurement. Reproducibility of WHVP Measurement. Problems in HVPG Measurements Poorly trained operators Paper tracings not routinely obtained Method for WHVP measurements : not standardized

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Reproducibility of WHVP Measurement

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  1. Reproducibility of WHVP Measurement

  2. Reproducibility of WHVP Measurement Problems in HVPG Measurements • Poorly trained operators • Paper tracings not routinely obtained • Method for WHVP measurements : not standardized • Monitor recordings not accurate, when measurement repeated (variation <5% required to predict outcome based on hemodynamics response) (J GastroenterolHepatol 2004)

  3. Reproducibility of WHVP Measurement • Intraindividual variability in HVPG measurement – 8% (a coefficient of variation of 1mm Hg) • Significant difference in defining - in HVPG by more or less than 20% from baseline value - Value below or above 12 mm Hg - Changes the response status (Hepatology 2004)

  4. Reproducibility of WHVP Measurement • HVPG measurement : Minimal criteria for acceptable measurements • 30% of studies rejected : Uninterpretable tracings • Minimal criteria for technical adequacy - Rigorous protocol - Required equipment - Adequate calibration and recording - Actual measurements - Training operators (Hepatology 2004)

  5. Reproducibility of WHVP Measurement • Repeat HVPG measurement at least three times to make sure that values obtained are reproducible • If the values are not reproducible, check the wedged position of the catheter (Hepatology 2004)

  6. Reproducibility of WHVP Measurement (Hepatology 2004)

  7. Reproducibility of WHVP Measurement

  8. Reproducibility of WHVP Measurement • Heterogeneity of liver structure in cirrhosis - Intrahepatic heterogeneity of HVPG in cirrhosis • In patients with esophageal varices -HVPG normal in one hepatic vein -HVPG increased in second hepatic vein • Angiographic signs of intrahepatic vascular shunting with drainage of contrast from catheter tip in wedged position (Scand J Gastroenterol 2002)

  9. Reproducibility of WHVP Measurement Intrahepatic hepatic vein-to-hepatic-vein shunts

  10. Reproducibility of WHVP Measurement • HVPG measurement in two separate hepatic veins Difference of 4-34 mmHg in 61% • Difference of 4 mm Hg : 20% change if baseline HVPG is 20 mm Hg • Hemodynamic response by percent HVPG decrease : questionable due to variability in measurement • With cannulation of same hepatic vein intrasubject variation of 1-2 mm Hg : makes difference in considering whether HVPG is above or below 12 mm Hg or decrease is more or less than 20% from baseline (Gut 2007)

  11. Reproducibility of WHVP Measurement • HVPG measurements in two separate hepatic veins • In cirrhosis Two measurements - Agreed within ± 3.6 mm Hg in 39% - Differed by 4-34 mm Hg in 61% • In 35%, fluoroscopy demonstrated hepatic vein-to-hepatic vein shunting in veins with low HVPG values • In some patients with HVPG > 30 mm Hg, doppler ultrasound showed arterialization of hepatic vasculature • In 26%, one measurement was below 12 mm Hg and the other measurement above 12 mm Hg (Scand J Gastroenterol 2002)

  12. Reproducibility of WHVP Measurement Relationship between values of the hepatic venous pressure gradient (HVPG) in two separate liver veins

  13. Reproducibility of WHVP Measurement (Hepatology 2004)

  14. Reproducibility of WHVP Measurement Balloon Catheter vs Straight Catheter n=47 • BC and SC used in sequence to measure HVPG during same procedure Variation Coefficients for Triplicate Measurements • BC more reproducible and reliable in determining HVPG than the SC: Smaller variations of WHVP (Aliment PharmacolTher 2010)

  15. Reproducibility of WHVP Measurement Comparison of WHVP and Portal Pressure • WHVP measurements obtained with BC: Higher correlation with directly obtained intraportal pressure than WHVP measurements obtained with SC (Aliment PharmacolTher 2010)

  16. Reproducibility of WHVP Measurement Balloon-tipped catheter : HVPG values accurate and reproducible • Balloon catheter occludes a larger hepatic venous branch and measures WHVP over wider vascular territory of the liver • Balloon catheter allows repeated measurements from the same hepatic vein and avoids the decompressive effect of venous-to-venous shunts that are proximal to balloon • Straight catheter has to be advanced and withdrawn for each WHVP and FHVP measurement :difficult to wedge same venule with each successive pressure determiation Pressure tracings : annotated and recorded (Hepatology 2004)

  17. Reproducibility of WHVP Measurement WHVP measurement : Reproducible - Trained operator - Standard method - Proper equipment - Balloon-tipped-catheter - Measurement in same hepatic vein

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