Prediction of portal pressure from intraoperative ultrasonography

Portal hypertension is a major risk factor for hepatic failure or bleeding in patients who have undergone hepatectomy, but it cannot be measured indirectly. We attempted to evaluate the intraoperative ultrasonography parameters that correlate with portal pressure (PP) in patients undergoing hepatectomy.

We examined 30 patients in whom PP was directly measured during surgery. The background liver conditions included chronic viral liver disease in seven patients, chemotherapy-associated steatohepatitis in four patients, fatty liver in one patient, hepatolithiasis in one patient, obstructive jaundice in one patient, and a normal liver in 16 patients. A multivariate logistic analysis and linear regression analysis were conducted to develop a predictive formula for PP.

The mean PP was 10.4 ± 4.1 mm Hg. The PP tended to be increased in patients with chronic viral hepatitis. A univariate analysis identified the association of the six following parameters with PP: the platelet count and the maximum (max), minimum (min), endo-diastolic, peak-systolic, and mean velocity in the portal vein (PV) flow. Using multiple linear regression analysis, the predictive formula using the PV max and min was as follows: Y (estimated PP) = 18.235-0.120 × (PV max.[m/s])-0.364 × (PV min). The calculated PP (10.44 ± 2.61 mm Hg) was nearly the same as the actual PP (10.43 ± 4.07 mm Hg). However, there was no significant relationship between the calculated PP and the intraoperative blood loss and post hepatectomy morbidity.

This formula, which uses ultrasonographic Doppler flow parameters, appears to be useful for predicting PP.