Objective: The aim of this study was to explore the underlying pathophysiological mechanism for portal hypertension in primary biliary cirrhosis (PBC) using radiological findings.
Patients and methods: The study included 10 patients with PBC (Scheuer stage I, one patient; stage II, two patients; and cirrhosis, seven patients) and 29 patients with viral cirrhosis. Both groups underwent Doppler ultrasound and hepatic venous catheterization. The Doppler data, pressure data, and vascular enhancement findings were compared between the groups.
Results: Hemodynamics in the portal trunk and hepatic vein upon Doppler sonography did not differ between patients with viral cirrhosis, cirrhotic PBC, and noncirrhotic PBC. The hepatic venous pressure gradient (mean±SD) was 225.5±77.1 mmH2O (range 125-445 mmH2O) in viral cirrhosis, 224.6±39.5 mmH2O (range 170-262 mmH2O) in cirrhotic PBC, and 41.3±7.4 mmH2O (range 33-47 mmH2O) in noncirrhotic PBC, being significantly higher in viral cirrhosis and cirrhotic PBC than noncirrhotic PBC (P=0.0005). The intrahepatic portal vein was detected in a retrograde manner on the hepatic venogram in 29/29 (100%) patients with viral cirrhosis (all with gastroesophageal varices), 7/7 (100%) patients with cirrhotic PBC (5/7 with gastroesophageal varices), and 3/3 (100%) patients with noncirrhotic PBC (none with gastroesophageal varices). The presence of veno-venous communication was found in 15/29 (51.7%) patients with viral cirrhosis, 6/7 (85.7%) patients with cirrhotic PBC, and 3/3 (100%) patients with noncirrhotic PBC.
Conclusion: The study suggested that sinusoidal blockage is the underlying pathophysiology even in the early-stage PBC, proved by the visible intrahepatic portal vein in three noncirrhotic PBC patients, and veno-venous communication in the liver is responsible for alleviated hepatic venous pressure gradient.