EUS-guided Liver Biopsy and Portal Pressure Gradient Measurement

Endoscopic ultrasound-guided liver biopsy (EUS-LB) is a safe alternative to percutaneous and transjugular routes with comparable diagnostic yields. It is very suitable for the biopsy of both the hepatic lobe and can be used to assess the portal pressure gradient (PPG) simultaneously.

The basic steps performed in the EUS-LB technique are: 

•  Localize avascular path in the liver using gastric cardia in the left hepatic lobe or from D1 in the right hepatic lobe.
•  Puncture through gastric or duodenal wall liver using a quick stroke.
•  After entering the liver parenchyma, turn on the suction by turning the stop-clock.
• Take around three actuations with the to-and-fro movement of the needle.
• Needle travel: 3 cm course of the needle travels sufficient, but a longer needle can be used if the condition permits.
• Turn off the suction before removing the needle from the liver.

EUS-PPG is found to have a good correlation with the hepatic venous pressure gradient. Mathematically, it can be defined as “Portal pressure gradient (PPG) = Portal venous pressure - Free hepatic venous pressure.”

Some important tips to remember while performing the EUS-PPG technique are:

• Sedative agents are the Achilles heel of EUS-PPG as they can affect the portal hemodynamic.
• Low doses of midazolam are preferred if needed.
• Entry site of the vessel should be surrounded by adequate liver parenchyma for tamponade.
•  When the needle is passed into the hepatic vein, flush the needle with hep-saline before recording the pressure reading.
• Take at least three pressure readings.
•  Re-flush the needle before taking the readings.