EUS Guided Portal-systemic Pressure Gradient Measurement

Currently, the gold standard in measurement of portal hypertension is via measurement hepatic venous pressure gradient (HVPG). The HVPG has been shown to correlate with risk of clinical decompensation, development of varices, hepatocellular carcinoma, variceal bleeding, spontaneous bacterial peritonitis and mortality. The technique involves ultrasound guided puncture of the internal jugular vein, followed by passage of a balloon catheter from through the right atrium, IVC and right hepatic vein. The free hepatic vein venous pressure is then measured followed by the wedge balloon venous pressure. The HVPG is then calculated by subtracting the free hepatic venous pressure from the wedge balloon venous pressure. When HVPG is \>10mmHg, the risk of developing varices is increased. If \>12mmHg, then risk of variceal bleeding is increased. Mortality risk is increased when HVPG is \>16-20mmHg. Nevertheless, the technique is technically difficult and it may not be available even in tertiary medical centres \[8\]. Furthermore, it requires the use of ionic contrast and also has a low acceptance rate amongst patients. The aim of the current study is to investigate the feasibility of EUS-PPGM using the novel device and correlate the risk of developing complications with the PPGM in patients that are suffering from chronic hepatitis. Recently, the use of EUS-guided approach for measurement of portal pressure gradient (PPGM) has been shown to be feasible. PPGM by the EUS approach was found to have excellent accuracy and strong correlation with pressure values obtained by the criterion standard transjugular wedged and free hepatic venous pressure measurements by interventional radiology in an animal model. Furthermore, in a pilot study involving 29 patients. The technical success rate was 100% and no adverse events were reported. Measurements obtained with the EUS approach was shown to correlate excellently with clinical parameters of portal hypertension including presence of varices, portal hypertensive gastropathy and thrombocytopenia. Furthermore, the procedure could be performed at the same time of screening oesophagogastroduodenoscopy (OGD), that is frequently required for variceal screening in this group of patients. However, whether the technique could reproduce results similar to HVPG in humans is uncertain.