Letter: Post-TIPS Hepatic Encephalopathy—The Long-Term Mortality Conundrum in Cirrhotic Patients With Portal Hypertension

We read with interest the recently published article by Xiang et al., entitled ‘Post-TIPS Overt Hepatic Encephalopathy Increases Long-Term but Not Short-Term Mortality in Cirrhotic Patients With Variceal Bleeding: A Large-Scale, Multicenter Real-World Study’ [1]. The authors highlighted that post-TIPS overt hepatic encephalopathy (OHE) is associated with an increased risk of long-term, but not short-term, mortality in cirrhotic patients with portal hypertension. Their study provides valuable insights into the long-term implications of OHE and its significance for the management of portal hypertension in this patient population. However, there are a few considerations remaining.

First, the author did not emphasise whether the stent access was through the right or middle hepatic vein, nor did they specify if the stent was positioned in the left or right portal vein, which may influence the incidence of OHE.

A meta-analysis comparing the clinical efficacy of stents placed in different portal vein branches manifested that the rate of postoperative HE was significantly lower in the left portal vein group compared to the right portal vein group (5.7% vs. 18.1%, OR 0.19; p < 0.00001) [2]. Hence, more details about the TIPS procedure and subgroup analysis are needed to draw a robust conclusion.

Second, the study did not investigate the impact of TIPS stent diameter, which had a notable influence on mortality according to Table 3 [1]. Specifically, a previous study conducted by Yan et al. showed that, compared to a conventional 8-mm shunt, the 6-mm TIPS stent significantly reduced the incidence of OHE after TIPS (27.6% vs. 12.1%, p = 0.040, 1-year; 36.2% vs. 19.0%, p = 0.038, 2-year) and protected perioperative liver function for patients with small liver volume [3]. Therefore, we assume that a lower stent diameter can reduce the risk of post-TIPS OHE and thus decrease long-term mortality.

Third, the presence of spontaneous portosystemic shunts (SPSS) is an often-overlooked risk factor that may reduce hepatic perfusion and contribute to the development of OHE [4, 5]. However, the potential role of SPSS embolisation was not addressed in the article. The association between SPSS and OHE or mortality needs further discussion. Since there is evidence showing that the 2-year cumulative incidence of OHE was significantly lower in the TIPS plus simultaneous SPSS embolisation (TIPS + E) group compared with the TIPS group (21.2% vs. 48.3%; HR: 0.38, 95% CI, 0.15–0.97; p = 0.043), so did the death rate (15.0% vs. 6.9%, p = 0.352) [6].

Fourth, the author conducted propensity score matching with a caliper width set at 0.2, which may lack statistical rigor. Additionally, while the authors stated that standardised mean differences (SMD) were calculated before and after matching to assess intergroup balance, these results were not presented in the article. We recommend including a visual representation of the SMD to enhance the transparency and credibility of the findings.

In conclusion, although the aforementioned viewpoints deserve careful consideration, we congratulate and appreciate their contribution for guiding management strategies to improve long-term outcomes in post-TIPS patients.