Following two years of intensive engineering and redesign efforts, Gore has announced the release of its new modified thoracic endoprosthesis. The full launch takes place at the 26th Charing Cross International Symposium with the Gore satellite symposium 'It's Back! The New and Improved Gore TAG Thoracic Endoprosthesis' at 8.00am on Monday, 5 April.
Gore states that the Gore TAG Thoracic Endoprosthesis offers "the same advanced features as the original design but with greater durability". Gore has devoted considerable resources and attention to improving the long-term durability of the endoprosthesis through countless iterations of the design and subjecting the re-engineered device to the most rigorous motion and performance tests. The design enhancements, involving the removal of the longitudinal support wire (spine) and strengthening of the graft, ensure a lower risk of stent wire fractures and subsequent potential graft disruptions.
Vascular News was present at the pre-launch meeting of the Gore TAG endoprothesis for thoracic aortic disease on 5 March at Guy's Hospital in London, UK. The launch was accompanied by a whole series of lectures on the new product and about TAA treatment in general.
Gore's pedigree in the TAA and AAA stent graft marketplace was underlined by Sabina Betti from the company's European HQ in Italy. She stated that 13,000 AAA implants had taken place world wide using the Gore Excluder. However, the main focus of the proceedings was naturally on the TAG product. The audience was reminded that the first implant was actually in 1998 but, because of resultant fractures running at an unacceptably high level of 16% in the overall US studies, the device was withdrawn from the market before its reintroduction this year.
Since then wide clinical trials have taken place to ensure the device's safety. Outside of the US 1,700 patients had been implanted with 2,500 devices. Within the US, the respective figures were 376 and 574.
Micheael Nilson, who was heavily involved in the design of the new product, explained to the audience that the aim of the revised TAG was threefold:
Maintain safety and efficacy performance
To eliminate the longitudinal spine wire
To leverage TAG device clinical experience
The revised and earlier versions actually look very similar. However, there have been modifications to improve its stability. As outlined above the longitudinal spine wire is no longer there and the actual EPTFE/FEP graft has been made stronger. The fact that a new layer is sandwiched between existing levels provides the necessary longitudinal stiffness. The new version has a uniform bonding film and increased abrasion resistance, as there is no spine channel and no untaped apices.
The audience found out that the device had undergone two years of rigorous testing and 1,000 devices had been built and tested. Use and durability tests included deployment accuracy, bend ratius, bending/pulsable fatigue tests and abrasion resistance. In addition a 180-day duration sheep test had taken place. At this stage the audience asked what practical use the flares were and were told that the flare helps get apposition to the artery wall.
The new device had the following vessel diameters 23-24mm, 24-26mm, 26-29mm, 29-32mm, 32-34mm and 34-7mm. Mr Nilson mentioned that the company was looking at developing larger sizes and new devices for treating thoracic aortic disease. Length options were 10cm, 15cm and 20cm. The 7.5cm and 12.5cm lengths were no longer being produced due to lack of demand from the surgeons for these products.
In terms of the accompanying devices there have been some noteworthy modifications. The tri-lobe balloon, however, remains unmodified. There is one size for all TAG devices with 108cm working length. Several recommended balloon volumes were given, with the warning that overfilling could lead to rupture. Mr Nilson did, however, assure the audience that there were working on a balloon that could "handle more volume".
Gore introduced the TAG introducer sheath. Previously the Cook KTI sheath had been used with the TAG device. The TAG sheath is up to 1FR smaller in OD than the Cook KTI device. Three device caps are used with the TAG but as they are not colour-coded care is needed in deployment. Although they look very similar they do display different characteristics in use.
It was revealed in discussions with Petra Ruegamer, the European product manager for the Gore TAG, that the device had already been implanted three times in the UK at Guy's and also in the following countries: Austria, Germany, Spain and Switzerland.
After the device was presented several scientific talks followed. Here are the highlights:
Michael Dake (Stanford) discussed the state of art treatment of acute dissection. He stated that there were 14/20 per million population and that untreated mortality after one month could be as high as 83%. He underlined the importance of improving surgical and endovascular treatments
Ludger Sunder-Plassmann, current president of the German vascular surgery society, gave a talk on stent graft treatment of dramatic transection. From studies done at Ulm where he works concluded that:
It can be done together with open procedures
There was no paraplegia in the cases he treated
In the LSA overstenting was necessary in 70% or more of cases
Midterm survival rates were excellent.
Peter Taylor discussed the endoluminal treatment of mycotoic aneurysms. He felt that endoluminal repair was an attractive option especially in unfit patients and presented data to support this case.
Rachel Bell presented the Eurostar and UK thoracic registries. The results she produced demonstrated that thoracic aortic disease is associated with significant co-morbidity.
The attendees finished the day at the nearby Vinopolis restaurant. The whole event, chaired by John Reidy, was a success with many leading vascular surgeons attending to hear about the Gore TAG device.
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