To establish the sensitivity and specificity of the mean portal flow velocity in the diagnosis of portal hypertension, a population of 304 consecutive cirrhotic patients, in whom 246 abdominal Doppler examinations were performed, was prospectively analysed between June 1988 and December 1990. To avoid equipment-related variability only examinations performed using the same equipment were considered. Further inclusion criteria were the absence of portal vein thrombosis or reversed flow in the portal vessels and the absence of spontaneous, ultrasonographically detectable, portosystemic shunts. The parameter evaluated was mean portal flow velocity calculated directly from the Doppler trace by specific, operator-independent, software. 123 patients satisfied the inclusion criteria. As a control group 60 healthy age- and sex-matched subjects were examined. Mean portal flow velocity was significantly lower in cirrhotic patients than healthy subjects (13.0 +/- 3.2 cm/s vs. 19.6 +/- 2.6 cm/s; p < 0.00 1). There was also a decrease in mean portal flow velocity in cirrhotics in each Child-Pugh category (13.8 +/- 2.8 cm/s in Child-Pugh A class; 12.1 +/- 3.5 cm/s in Child-Pugh B class and 11.0 +/- 2.4 cm/s in Child-Pugh C class) with a statistically significant difference between each Child-Pugh category and healthy subjects (p < 0.001), between Child-Pugh A and B (p < 0.01) and between Child-Pugh A and C (p < 0.005). The sensitivity and specificity of mean portal flow velocity in the detection of portal hypertension was then analyzed with the receiver operating characteristic curve. The value of 15 cm/s was considered the best cutoff value, showing a sensitivity and specificity of 88% and 96%, respectively. Our results demonstrate the usefulness of Doppler flowmetry in the diagnosis of portal hypertension. In this study we also established a mean portal flow velocity value for our instrumentation which could accurately identify portal hypertensive patients.
