Liver and spleen elastography in diagnosis of extrahepatic portal vein obstruction: pilot study
Aim of investigation. To estimate diagnostic value of liver and spleen elastography in patients with extrahepatic portal vein obstruction - non-cirrhotic portal vein thrombosis (PVT). Material and methods. The study group: 19 patients (Age 21-76 years) with PVT diagnosed by multispiral computed angiography without liver/pancreatobiliary tumors and/or liver cirrhosis (LC). The comparison group included 23 patients with LC Child-Pugh class A. Past history of portal hypertension, platelet count, serum albumin level, alanine and aspartate aminotransferase level; prothrombin according to international normalization ratio; grade of esophageal varices (EV); spleen longitudinal size according to abdominal ultrasound, liver and spleen stiffness were evaluated in both groups. Results. The group of patients with non-cirrhotic PVT was characterized by presence of clinically significant portal hypertension (EV, splenomegaly and hypersplenism). Following causes for PVT were established: systemic factors - myeloproliferative diseases, G20210A prothrombin gene mutation, and local factors: complications after pancreatobiliary surgery, omphalitis and neonatal umbilical sepsis. Nine patients, 1 to 2 years prior to hospitalization, were previously misclassified as «cryptogenic liver cirrhosis» in various medical institutions. Liver stiffness in PVT group was 2,8-11,5 kPa. The grade of EV tended to increase along with progression of the spleen stiffness. Statistically significant difference in serum aminotransferases levels in non-cirrhotic PVT vs Child-Pugh class A HCV-LC was observed: enzyme levels were 1,5-2 fold higher in LC (р<0,0001). No differences in the protein-synthetic liver function and severity of thrombocytopenia were found. Prevalence of EV was higher in non-cirrhotic group (р=0,028).) Statistically significant differences between groups in a liver stiffness were revealed: in non-cirrhotic PVT patients the median liver stiffness was 5,6 kPa, in LC patients it was 20,6 kPa, (p<0,0001). Conclusions. Liver elastography is rational in patients with primary diagnosed portal hypertension and PVT. For the differential diagnosis between LC-related PVT and the non-cirrhotic PVT the cut-off value of 11,5 kPa can be applied. Plotting of multifactorial model requires further studies with larger number of patients. Diagnostic value of spleen stiffness measurement as method for noninvasive diagnostic of degree of portal hypertension in non-cirrhotic PVT has been confirmed by the published data. Estimation of a cut-off value to predict EV development and EV bleeding in these patients requires larger number of patients and considering confounding factors.