Quantitative Assessment of the Portal Pressure for the Liver Surgery Using Serological Tests

Abstract

Objective: To establish a reliable equation to predict hepatic venous pressure gradient (HVPG) using serological tests for surgical patients with hepatocellular carcinoma (HCC).

Background: Accurate assessment of portal pressure for surgical patients with HCC is important for safe hepatic resection (HR). The HVPG is regarded as the most reliable method to detect portal hypertension. However, HVPG is not utilized in many medical centers due to invasiveness of procedure.

Methods: Between 2006 and 2008, 171 patients (Correlation cohort), who underwent liver surgery in a tertiary hospital, were enrolled. Preoperative measurements of the HVPG and serological tests were performed simultaneously. Correlation between the HVPG and serological tests were analyzed to establish an equation for calculated HVPG (cHVPG). Between 2008 and 2013, 510 surgical patients (Application cohort) were evaluated, and HR recommended when cHVPG < 10 mm Hg. The outcomes of HR were analyzed to evaluate reliability of the cHVPG for HR.

Results: In the correlation cohort, the equation for cHVPG was established using multivariate linear regression analysis; cHVPG (mm Hg) = 0.209 × [ICG-R15 (%)] - 1.646 × [albumin (g/dL)] - 0.01×[platelet count (10)] + 1.669 × [PT-INR] + 8.911. In the application cohort, 425 patients with cHVPG < 10 mm Hg underwent HR. Among them, 357 had favorable value of ICG-R15 < 20% (group A), and 68 had unfavorable value of ICG-R15 ≥ 20% (group B). There was no significant difference in patient demographics, tumor characteristics, operative outcome, and survival rates between group A and B.

Conclusions: The equation for cHVPG of this study was established on statistical reliability. The cHVPG could be useful to predict portal pressure quantitatively for surgical patients with HCC using serological tests.

FIGURE 1

Correlation of HVPG with serological tests in the correlation cohort. Hepatic venous pressure gradient was significantly correlated with serological tests of ICG-R15, serum albumin, platelet count, and prothrombin time by multivariate analysis. Among them, the ICG-R15 had the most significant correlation with HVPG (R² = 0.656). ICG-R15 (A) and prothrombin time-international normalized ratio (D) were positively correlated to HVPG (P < 0.05), and serum albumin level (B) and platelet count (C) are inversely correlated to HVPG (P < 0.05). A total of 95% prediction intervals are shown as dashed lines. Locally weighted scatter plot smooth for each serological test is shown as dotted line.

FIGURE 2

The scatterplots between hepatic venous pressure gradient and calculated hepatic venous pressure gradient. A total of 95% prediction intervals were shown as dashed lines.

FIGURE 3

Receiver operating characteristics curve for calculated hepatic venous pressure gradient values in the correlation cohort to predict absence of portal hypertension (hepatic venous pressure gradient <10 mm Hg). A, The maximal value of Youden index. B, P < 0.001.

FIGURE 4

Treatment flow chart of the hepatocellular carcinoma patients in the application cohort by the cHVPG. The surgical patients with hepatocellular carcinoma in the application cohort were evaluated and selected for hepatic resection according to cHVPG. The hepatic resection was considered for the patients with cHVPG < 10 mm Hg. The hepatic resection was not recommended to the patient with cHVPG ≥ 10 mm Hg (n = 41). The hepatic resection was performed for the patients in group A and group B regardless of indocyanine green retention test.