Editor's Note: Portal hypertension can lead to complications such as variceal bleeding and ascites. Transjugular intrahepatic portosystemic shunt (TIPS) creates an artificial channel between the hepatic vein and portal vein to reduce portal pressure. TIPS is the only minimally invasive method that can reduce or even normalize portal pressure and is effective in controlling variceal bleeding and refractory ascites. However, American, Chinese, and European guidelines recommend endoscopic treatment, non-selective beta-blockers, and paracentesis as the first-line treatments for variceal bleeding and ascites related to portal hypertension, with TIPS recommended as an alternative treatment. One of the main reasons is that TIPS can induce overt hepatic encephalopathy (HE), with an incidence rate of 10% to 50%, negatively affecting patients' quality of life and increasing mortality. Even with multiple treatments, the recurrence rate of HE remains high. These factors make predicting the risk of overt HE crucial for determining patient eligibility for TIPS. Recently, a study by Dr. Ligong Lu from Zhuhai People's Hospital, published in Hepatology International, explored the feasibility of using liver vascular assessments to predict HE, providing evidence to support the selection of suitable patients for TIPS treatment.Background
Predicting HE has been a focal point in cirrhosis-related research. Previous studies have focused on clinical or biological factors mainly related to liver function. However, the integrity of the liver vascular system (portal vein, hepatic artery, hepatic vein, and hepatic sinusoids) is fundamental to liver function. An increased mean diameter of the portal vein is considered an indicator of portal hypertension. When portal hypertension occurs, increased blood flow, increased vascular resistance, or both may affect the portal vein diameter and the liver’s ability to detoxify toxic substances (especially plasma ammonia), influencing the occurrence of overt HE. Previous studies have shown that morphological assessments of the liver and spleen are feasible for predicting the occurrence of overt HE after TIPS. Therefore, morphological assessments of the liver vascular system might provide additional information for predicting overt HE after TIPS.
To give patients with variceal bleeding and ascites related to portal hypertension an opportunity for therapeutic rather than palliative TIPS treatment, researchers conducted this study to evaluate morphological changes in liver-related vessels to improve the accuracy of predicting the risk of overt HE.
Methods
This multicenter study included 621 patients who received TIPS for variceal rebleeding and/or refractory ascites. They were divided into a training group (n=413) and an external validation group (n=208). In addition to traditional clinical factors, researchers used the maximum diameter (including absolute values and ratios) to assess morphological changes in liver-related vessels and used logistic regression to establish three prediction models (clinical model ModelC, vascular model ModelV, and combined model ModelC-V). The models’ discrimination and calibration were compared to test the necessity of liver vascular assessments and determine the best model. To verify the improved performance of ModelC-V, it was compared with four previous models, including identification and calibration.
Results
The combined model outperformed the clinical model and the vascular model (training group AUC: 0.814 vs. 0.754, 0.727; validation group AUC: 0.781 vs. 0.679, 0.776; P<0.05), with the best calibration. Compared to previous models, ModelC-V had better identification performance. The difference in HE incidence among high, medium, and low-risk groups was statistically significant (P<0.001). Although pre-TIPS plasma ammonia levels had limited ability to predict the risk of overt HE, the combined model showed satisfactory predictive ability for overt HE risk in both low and high ammonia subgroups.
Conclusion
Liver vascular assessment improved the accuracy of predicting overt HE, ensuring that suitable patients have the opportunity for TIPS treatment and providing insights for cirrhosis-related research.
