Efficacy of 6-mm and 8-mm transjugular intrahepatic portosystemic shunt for variceal bleeding: A randomized controlled trial

TIPS: The smaller, the better?

At the beginning of the TIPS era in the early 1990s, portosystemic shunts were commonly created using stents dilated to 10 or even 12 mm. However, in the following decades, increasing attention was directed toward the risk of hepatic encephalopathy after TIPS (post-TIPS HE) and toward defining the optimal portosystemic gradient (PSG) required for reducing portal hypertension. As a result, stents with smaller diameters came into focus. 
This shift was reinforced by a study from the Bonn TIPS group comparing 8-mm and 10-mm stents, which showed similar rates of post-TIPS HE but a survival advantage in the 8-mm stent group (DOI: 10.1016/j.cgh.2019.03.042). Following these findings, the 8-mm stent became the new standard of care. 
The manufacturer of an approved TIPS stent with fixed diameter subsequently adapted the device design and developed a controlled expansion stent allowing individual dilation from 8 to 9 or 10 mm depending on the PSG. However, this range was not considered sufficient in all clinical situations. In certain settings, such as pediatric patients, pre-existing cardiac insufficiency, or known risk factors for post-TIPS HE, a stent diameter of less than 8 mm appeared advantageous. 
In response to these needs, the manufacturer has further expanded the available options. Since 2026, the controlled expansion stent has been available in diameters ranging from 6 to 10 mm. 
This is why the study presented here comes at the right time. When placing a TIPS, one of the central questions for interventional hepatologists is which stent diameter should be selected for which patient. This decision involves multiple factors, including technical-interventional aspects, clinical-hepatological considerations, and cardiocirculatory factors.
The single-center Chinese study by Zhang et al. compares 2 groups: 72 patients who received a 6-mm TIPS stent and 72 patients who received an 8-mm stent. Several limitations should be noted at the outset. First, the study population may not be readily comparable to patient populations of European ancestry. This is reflected in the baseline characteristics: Liver cirrhosis was predominantly of viral etiology, more than 5% of the total cohort had undergone splenectomy before TIPS (a procedure that used to be quite common in China for variceal bleeding), and the stent configuration used (ePTFE-covered stent combined with an uncovered nitinol stent) differs significantly from the controlled expansion stent commonly used in western countries. 
Despite these limitations, the results are interesting. The study highlights a reduction in the 2-year cumulative incidence of post-TIPS HE with the 6-mm stent (42.0% vs. 20.3%; p = 0.009). However, I would like to add that the pre-TIPS HE rates in the 8 mm group were already about twice as high (8.3% vs. 4.2%; p = 0.494). 
The lower HE rate comes at the cost of less effective control of portal hypertension. Although patients with the 6-mm stent also had a postprocedural PSG of 10 mm Hg (range 8.0–14.0), corresponding to a mean reduction of 57% (range 43–64), the rate of rebleeding was higher (33.3% vs. 22.2%; p = 0.193). The reasons for the overall relatively high bleeding rates compared to historical variceal studies are not discussed by the authors. Two-year survival was almost identical in both groups.
With the publication of this study and the approval of the controlled expansion stent in diameters ranging from 6 to 10 mm, the discussion about the optimal TIPS stent diameter below 8-mm has gained considerable momentum. This study has not yet convinced me to routinely use only 6-mm stents. However, the findings provide an additional argument for starting with a diameter below 8 mm in patients at a high risk for post-TIPS HE (e.g., advanced age, sarcopenia, impaired liver function as reflected by MELD/Child-Pugh score). I have often experienced that HE represents a significant psychosocial burden for patients and their families. In addition, subsequent dilation is still an option!