LAUSR

To the Editor, We read with great interest the paper by Wang et al, where the authors compared the ability of the Child‐Pugh (CP) score, the model for end‐stage liver disease (MELD) score and the indocyanine retention test at 15 minutes (indocyanine green [ICG]‐R15) to assess hepatic functional reserve in patients undergoing to hepatic resection. The authors retrospectively evaluated 185 patients with hepatocellular carcinoma suitable for hepatic resection. Using multivariable analysis they found that platelet count, ICG‐R15, clinically significant portal hypertension (PH) and major resection were independent factors for predicting severe posthepatectomy liver failure (PHLF). The authors concluded that ICG‐R15 was more accurate than the CP and MELD scores in predicting hepatic functional reserve before hepatectomy. These results are very interesting because, apart from major hepatic resection, the other predictors of PHLF were associated to PH. The gold standard method to assess the presence and the degree of PH is the measurement of hepatic venous pressure gradient (HVPG). Moreover, the HVPG can be used before surgery to stratify the risk of PHLF. However, HVPG is an invasive and risky method, not available in all hospitals. On the other hand, in the last decade several noninvasive tests have been evaluated for the prediction of PH in different settings. Indocyanine green retention test (ICG‐R15) is one of these. Lisotti et al documented that ICG‐R15 was also able to directly reflect the alteration of liver blood flow and consequently the presence and grade of PH and esophageal varices of patients with well‐preserved liver function. Furthermore, Cescon et al found that an elevated liver stiffness measurement (LSM), which is also a surrogate marker for PH, was associated with PHLF. More recently, two new noninvasive tests were proposed as good predictors of PH, liver stiffness‐spleen size‐to‐platelet ratio risk score (LSPS) by Kim et al and spleen stiffness measurement (SSM) using transient elastography by our group in 2012. SSM was found to have an higher accuracy than LSM in predicting PH grade. Thus, using Wang’s experience we collected data and analyzed the role of other noninvasive tests such as SSM and LSPS as surrogates for PH in predicting PHLF in a previously published cohort of resected patients for HCC. Among the 90 patients, 26 experienced severe PHLF (grade 2 or 3). Figure 1A and 1B shows SSM and LSPS distributions in no‐PHLF and PHLF, which were significantly different between the two groups (P < 0.01). While LSPS was available for all the patients, SSM data were available in 40 patients, of whom 16 experienced PHLF. Thus, we were able to perform only a univariate analysis for testing the predictive role for PHLF. Accordingly, we found that SSM and LSPS were both significantly associated with PHLF (Table 1). In conclusion, according to Wang’s and our results, PH is the strongest predictor of posthepatectomy liver failure. Thus, we believe it should be routinely assessed by noninvasive tests before hepatic resection.