Aortic Summit: At the peak of endografting

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The Gore Aortic Summit (January 2006) brought together the great and the good of the aortic world to discuss the latest advances in thoracic and abdominal stent-grafting.

Terri Kelly, CEO of WL Gore & Associates, began the Summit with an introduction to the company who last year celebrated “30 years of innovation and more milestones ahead… I appreciate the opportunity to be here today and participate in the second Aortic Summit. We feel that fora like this Aortic Summit are extremely valuable and serve as an excellent opportunity to learn firsthand from worldwide experts about how to use our products to maximize clinical outcomes”.

Kelly then discussed how Gore has emerged from humble beginnings to become a company that operates in more than 45 locations globally, manufacturing in the US, Germany, Scotland, China and Japan, with total revenues approaching $2 billion. In addition to its Medical Products Division, the company also has Fabric, Industrial and Electronics divisions.

It is of course the company’s focus on fluoropolymer materials, particularly those based on polytetrafluoroethylene (PTFE), that is behind much of its success. Indeed, more than 85% of its portfolio employs this core technology. Kelly continued, “Although our core competency as an enterprise is PTFE, we recognize the vast opportunities for complementary platforms within the medical technology market. One example would be our focus on bioabsorbable copolymer products. Gore is growing in the medical field through the same process that has been demonstrated to be successful in our other divisions. I wish all of you a very productive Summit.”

Thoracic aortic disease

Next, Dr Michael Dake discussed the role of endovascular therapy in thoracic aortic disease, claiming that stent-graft technology was now available and showing better results than its open repair equivalent. Dr Michael Makaroun then provided an update from the Gore TAG endoprosthesis trial. He said that those patients treated with the Gore TAG endoprosthesis had 94% rate of freedom from device-related events and a major adverse events rate of 44%, compared to 77% with surgery. Overall he said that the TAG device was safe and effective for treatment of aneurysms in the thoracic aorta.

Another highlight of the meeting was a presentation by Mike Nilson, who highlighted ten years of thoracic development and the lessons learnt. He began by stating that the development of the TAG and Excluder devices has taken many years. For example the TAG device first entered US clinical trials in 1997 and only received FDA approval in 2005.

Nilson said that a key component of the devices’ success was the company’s training program, which is designed to provide training and information on the product considerations and procedural elements necessary to properly select, treat and follow patients.

Nilson added that the success of the clinical results, in conjunction with the training course has resulted in the implantation of more than 13,000 TAG devices so far. So far the company has received 300 complaints, of which only 2% were device-related (and less than 0.5% were of serious adverse events).

He then commented that the device has gone through several modifications since its initial conception. The original device incorporated a spine that was later removed after it fractured in a higher than anticipated number of clinical implants. The device’s bend radius was also improved.

Beginning the next session, Dr Venkatesh Ramaiah from the Arizona Heart Institute, discussed his experience with the Gore thoracic device. He revealed that the device had been implanted in 40 patients with a technical success rate of 95% and an overall combined morbidity and early mortality of 5%. He added that the thoracic aneurysm remained stable or regressed in 30/31 patients at follow-up with no reported thoracic aortic ruptures. He concluded that the Gore Tag device may provide a level of stability to the thoracic aorta that is not present among many patients treated medically and without the high rate of attendant complications associated with open surgical repair.

ePTFE

Dr Zvonimir Krajcer then outlined the changes made in June 2004 to the Gore Excluder device. The graft material used was modified to resolve high permeability of the expanded PTFE graft wall by incorporating a high-density, less-permeable ePTFE film within the device.

The changes, Krajcer claimed, have resulted in an endograft that is more effective in reducing AAA volumes than the original endografts. The preliminary results available suggest that the new material is less permeable to fluids than the original, which therefore reduces the occurrence of hygroma and endotension. However, he warned, additional studies with larger patient numbers and longer follow-up are needed to confirm the preliminary data.