Portal hypertension is an increase in the pressure in the vein that connects the digestive organs to the liver and is most often caused by cirrhosis. Transjugular intrahepatic portosystemic shunt (TIPS) procedures create a new connection to reroute blood flow and reduce the difference in pressure, or pressure gradient, across the liver; a device such as the GORE VIATORR TIPS Endoprosthesis with Controlled Expansion keeps the new connection open.
“The goal in TIPS creation is to shunt as much blood as necessary to reduce portal pressure below the threshold that leads to portal hypertension complications, and as little blood as possible to maintain hepatic perfusion and cardiac output,” said Prof. Jonel Trebicka, M.D., Ph.D., Department of Internal Medicine, University of Bonn in Germany. “But when a stent is underdilated (less than the device’s nominal diameter), a common technique in pursuing the ideal gradient, the device diameter may increase over time reaching the nominal diameter in as little as six weeks. Since liver stiffness varies, the amount and rate of this passive expansion is unpredictable. As a result, the change in pressure, increase in shunting and increase in hyperdynamic circulation, factors that could potentially induce serious complications, are also unpredictable. The new capabilities of the GORE VIATORR TIPS Endoprosthesis with Controlled Expansion allow us to optimize the shunt diameter (at time of implantation) to achieve and maintain the desired portal pressure. The preliminary data show this forward-thinking attribute may result in direct patient benefits including reduced readmissions and complications such as hepatic encephalopathy.”
The physician-sponsored, case-control study is ongoing at the University of Bonn and continues to enroll patients in the Controlled Expansion arm. Preliminary findings were based on 21 patients receiving the GORE VIATORR TIPS Endoprosthesis with Controlled Expansion, and retrospective data of 48 patients receiving the GORE VIATORR TIPS Endoprosthesis and 36 patients receiving a bare metal stent. At three months, the GORE VIATORR TIPS Endoprosthesis with Controlled Expansion group showed significant superiority compared to both other groups in several areas including lower MELD-Na score (p = 0.019) and higher blood flow velocity (p = 0.002). Both the GORE VIATORR TIPS Endoprosthesis with Controlled Expansion group and the GORE VIATORR TIPS Endoprosthesis group experienced reduced early splanchnic vein thrombosis (p < 0.001) compared to the bare metal stent group. Both the GORE VIATORR TIPS Endoprosthesis with Controlled Expansion group and GORE VIATORR TIPS Endoprosthesis group experienced fewer readmissions from sepsis (p = 0.034). The GORE VIATORR TIPS Endoprosthesis with Controlled Expansion group experienced fewer readmissions from ascites (p = 0.006). Importantly, this beneficial effect was only observed after three months of implantation, suggesting that the lasting diameter control of Controlled Expansion may be at least partly responsible for the reduction in this post-TIPS complication. The study authors suggest that this underlines the importance of stent diameter control in the performing of TIPS. Further studies are necessary to confirm the benefits of lasting diameter control.
“The patency and performance data on our fixed-diameter GORE VIATORR TIPS Endoprosthesis is unmatched, but we understood the potential challenges of passive expansion if the stent is underdilated,” said Eric Zacharias, Gore Medical Vascular Business leader. “We're excited to see the preliminary results of this study which suggest that improved diameter control may reduce complications and resulting readmissions. We look forward to the long term results of the ongoing study at the University of Bonn.”
The GORE VIATORR TIPS Endoprosthesis with Controlled Expansion provides physicians novel diameter control capabilities to reach a targeted portal pressure gradient during implantation and set the diameter to stay. The addition of controlled expansion capabilities builds on the legacy of proven patency in de novo and revision TIPS procedures of the GORE VIATORR TIPS Endoprosthesis. The GORE VIATORR TIPS Endoprosthesis with Controlled Expansion features the same proprietary ePTFE graft lining that minimizes transmural permeation of bile and mucin (common causes of patency loss). With the new controlled expansion capability, physicians can start at the smallest diameter (8 mm) and balloon up as needed during implantation to optimize the diameter until the target pressure gradient is reached. Benchtop data on file showed diameter expansion was no more than 0.25 mm over a simulated 10-year period at physiological portal pressures. Further, the new device now covers a range of diameters between 8 and 10 mm in a single device, helping to simplify inventory.
The GORE VIATORR TIPS Endoprosthesis with Controlled Expansion is approved by the U.S. Food and Drug Administration and CE Marked for the treatment of portal hypertension with TIPS procedures.
Gore Medical Products Division engineers devices that treat a range of cardiovascular and other health conditions. With more than 40 million medical devices implanted over the course of more than 40 years, Gore improves patient outcomes through research, education and quality initiatives.
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1. Praktiknjo M, Lehmann J, Fischer S, Strassburg CP, Meyer C, Trebicka J. Novel diameter controlled expansion TIPS (Viatorr CX®) graft reduces readmission compared to regular covered TIPS graft and bare metal graft. Presented at The International Liver Congress (ILC); April 19-23, 2017; Amsterdam, The Netherlands. Journal of Hepatology 2017;66(Supplement):S48-S49. PS-084.