Fluoroscopic quantification of early in vivo expansion of VIATORR controlled expansion stent-grafts after TIPS: hemodynamic and clinical implications.

purposeThe VIATORR Controlled Expansion (VCX) stent-graft was developed to allow more precise control of shunt diameter during transjugular intrahepatic portosystemic shunt (TIPS) creation. However, real-world data on its actual in vivo expansion behavior and short-term clinical implications remain limited. This study aimed to provide fluoroscopic quantitative assessment of early in vivo expansion of VCX stent-grafts and to assess its association with short-term overt hepatic encephalopathy (OHE).

methodsThis single-center retrospective cohort included consecutive patients with cirrhosis who underwent TIPS using either a legacy 8-mm VIATORR TIPS stent-graft (VTS) or a VCX stent-graft. In the VCX group, stents were initially dilated to 8 mm and further dilated to 10 mm only when post-procedural portal pressure gradient (PPG) remained > 12 mmHg or decreased by < 50% from baseline. Propensity score matching (PSM) was performed to compare short-term clinical outcomes between the VCX and VTS groups. The primary imaging outcome was early in vivo expansion of the VCX controlled mid-segment, assessed by fluoroscopic diameter measurements at implantation and 3-month follow-up. The main clinical safety outcome was new-onset OHE within 6 months after TIPS.

resultsA total of 177 patients were included (108 VTS and 69 VCX). Among VCX patients with paired imaging follow-up, the mid-segment diameter increased from 8.0 mm at implantation to a mean of 8.65 mm at 3 months (range 8.2-9.1 mm; p < 0.001). Mean post-TIPS PPG increased from 7.7 mmHg immediately after TIPS to 11.6 mmHg at 3 months (p < 0.001), with no significant correlation between diameter change and PPG change. After PSM, 132 patients were analyzed. The cumulative 6-month incidence of OHE was numerically higher in the VCX group but did not reach statistical significance compared with VTS (HR 11.74, 95% CI 0.73-4.16; log-rank p = 0.204).

conclusionsVCX stent-grafts exhibit measurable early self-expansion after implantation, indicating that the controlled-expansion segment may not remain fixed at the intended 8-mm diameter during early follow-up. While the incidence of OHE did not differ significantly between the VCX group and the VTS group after PSM, the observed expansion underscores the dynamic nature of post-TIPS stent behavior and supports imaging-based follow-up of shunt configuration and hemodynamic status.