Portal vein thrombosis in patients with cirrhosis: does sonographic detection of intrathrombus flow allow differentiation of benign and malignant thrombus?

OBJECTIVE

The objective of our study was to determine if the detection by Doppler sonography of blood flow in portal vein thrombi occurring in patients with cirrhosis could be used to distinguish benign from malignant portal vein thrombi.

SUBJECTS AND METHODS

Color and duplex Doppler sonographic examinations were performed in 47 patients with proven cirrhosis and portal vein thrombi. The examinations were directed at the detection of continuous or pulsatile flow within the portal vein thrombi. The nature of the portal vein thrombi was proven histologically in 27 patients and by CT findings and clinical history in 20 patients. The frequency, type, and direction of portal vein thrombus flow was evaluated to determine if there was any correlation with the benign or malignant nature of the portal vein thrombi.

RESULTS

Of the 47 patients, 26 had malignant portal vein thrombi and 21 had benign portal vein thrombi. Blood flow was detected in 22 of the malignant and in 15 of the benign portal vein thrombi. The blood flow was pulsatile in 16 malignant and three benign portal vein thrombi and continuous in six malignant and 12 benign portal vein thrombi. The direction of the pulsatile flow in the malignant portal vein thrombi was predominantly (13/16) hepatofugal. All continuous flow in both benign and malignant portal vein thrombi was hepatopetal. The detection of pulsatile flow in portal vein thrombi yielded a 62% sensitivity and 95% specificity for the diagnosis of malignant portal vein thrombus.

CONCLUSION

The detection by Doppler sonography of pulsatile flow in portal vein thrombi occurring in patients with cirrhosis is a moderately sensitive but highly specific sign for the diagnosis of malignant portal vein thrombus. However, continuous flow can be detected in benign and malignant portal vein thrombus and is thus not useful in differentiating between the two.