The Gore Viatorr TIPS endoprosthesis with Controlled Expansion, a new device configuration developed by Gore, may reduce portal hypertension treatment complications, even when compared to the Gore Viatorr TIPS endoprosthesis, Gore’s legacy TIPS device. The latter has a strong history of patency and proven performance at fixed diameters. These findings were obtained from the abstract presented at The International Liver Congress 2017 in Amsterdam.
The preliminary data at three months also confirmed that hospital readmissions from cirrhosis-related complications, including refractory ascites and sepsis, were significantly reduced using either of the Gore Viatorr TIPS endoprosthesis products compared to bare metal stents.
“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 Jonel Trebicka, Department of Internal Medicine, University of Bonn, 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 optimise 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 in Germany and continues to enrol 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). 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 controlledeExpansion 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 Gore Viator TIPS Endoprosthesis with Controlled Expansion features the same proprietary ePTFE graft lining that minimises 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 optimise the diameter until the target pressure gradient is reached. Benchtop data on file showed diameter expansion was no more than 0.25mm 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 Viator TIPS Endoprosthesis with Controlled Expansion is US FDA approved and CE marked for the treatment of portal hypertension with TIPS procedures.