Can an incomplete stent expansion modulate the effects of TIPS?

Excerpt

We found the paper entitled TIPS for refractory ascites: a single center experience by Thalheimer et al. [1] to be of great interest, since it reports the retrospective analysis of their results obtained in patients with refractory ascites submitted to transjugular intrahepatic portosystemic shunt (TIPS) according to a protocol in which the stent used to construct the shunt was not completely expanded. The authors suggest that an incomplete stent expansion may reduce the occurrence of hepatic encephalopathy by also maintaining the efficacy of the shunt in terms of resolution of ascites. However, to test such a hypothesis, a randomized controlled trial comparing a limited versus a complete stent expansion should have been carried out. This was not the case, and, considering that the paper is a pilot study, we have some doubts regarding the methodology used and the possibility that a limited stent expansion can be useful in patients who need a TIPS. The portal pressure gradient (PPG) value that should be achieved after the stent expansion to solve the ascites and the PPG value that can avoid the occurrence of encephalopathy are in fact both unknown. It is therefore difficult to understand why the authors decided to stop the stent dilatation when the PPG reduction was more than 25%. Furthermore, we do not believe that the PPG value measured immediately after TIPS opening remains stable over time. Immediately after the procedure, in fact, the amount of blood reaching the heart increases rapidly, and a rise in the right atrium and the central venous pressure has already been described [2]. This value does not remain stable over time [3, 4]; it is therefore possible that a reduction of 25% in the PPG value measured immediately after TIPS may not be the same a few days or weeks later. We therefore wonder whether the authors have some evidence that the PPG value reached immediately after TIPS opening had remained stable over time. …