Standard technique in Japan for measuring hepatic venous pressure gradient.

Abstract

Direct measurement of portal venous pressure (PVP) is invasive, so the hepatic venous pressure gradient (HVPG) is commonly measured to evaluate portal hypertension (PH). HVPG is the gold standard for estimating PVP but few reports have covered standardized measurement techniques. This study validated standardized techniques for PVP measurement. In Western countries, electronic transducers are commonly used to measure PVP, whereas the water column method is still frequently applied in Japan. Setting a reference point for accurate PVP measurement is important but complicated. According to Japanese guidelines, the reference point for PVP measurement is 10cm above the dorsal surface or in the midaxillary line. For simpler determination, the anterior axillary point, defined as the point of convergence between the proximal pectoralis major muscle and arm when both arms are positioned against the trunk in a supine position, can be used as the reference point. New methods, such as endoscopic ultrasound-guided portal pressure gradient, offer less invasive alternatives. Non-invasive methods like elastography measure liver and spleen stiffness, which correlate with HVPG. The Baveno VII criteria incorporate measurements of liver and splenic stiffness for risk stratification. Biomarkers such as type IV collagen, M2BPGi, and FIB-4 score also predict HVPG. The Baveno VII consensus emphasizes the status of HVPG as the gold standard while advocating for non-invasive alternative methods to improve patient care and monitor treatment efficacy. Continued development of non-invasive tests is crucial for safer, more convenient PH management.