Study to assess stenting vs medical treatment in acute Type B dissections

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A new study announced at the Ajaccio international Workshop of Endovascular Surgery will assess the efficacy of endoluminal stent-grafting in patients with acute Type dissection.

Lead by Professor Jan Brunkwall, chief of vascular surgery at the University of Cologne, Germany, The Acute Dissection Stent-grafting OR Best Medical Treatment (ADSORB) study, is to investigate the mortality and re-intervention rate of dissection related diseases.

“The medical treatment of acute Type B dissection are not without complications and patients still die with this treatment,” said Brunkwall. “The purpose of the study was to investigate the mortality and the re-intervention rate due to dissection related disease (aneurysms in particular).”

The study will enrol 250 patients with acute (<14 days) Type B dissection (visual ischaemia or rupture) in 30 centres throughout Denmark, Sweden, Norway, Finland, Poland, UK, Germany and Austria. There will be CT pre-inclusion patient screening, followed by 'after' treatment within one month, and then three, six, 12 and 18, 24 and 36 months. The device to be used in the study is the Gore TAG Thoracic Endoprosthesis. This device offers the same advanced features as the original design, but with greater durability. The design enhancements, involving the removal of the longitudinal support wire and strengthening of the graft, ensure a lower risk of stent wire fractures and subsequent potential graft disruptions. Each year in Europe, an estimated 50,000 patients are diagnosed with lesions of the thoracic aorta, including those caused by Type B dissections. Many of these patients also have serious co-morbidities such as coronary artery disease, emphysema, high blood pressure or diabetes. These conditions make it difficult, if not impossible, for them to survive open surgical repair, which has been the standard of care. For those patients, considered ineligible for open surgical repair, conservative anti-hypertensive medical management, or ‘watchful waiting’, is often used as a treatment option. “This study is important because there is now a use of stent grafts in acute dissections, but [previously] we had no scientific proof with efficacy. There is a high mortality still in the best medical treatment group even though it’s slower than with open-surgery it is still high, rating from 10-30% within one year,” Brunkwall stated. He explained that this is the first study really examining acute dissection and not chronic ones. Other studies such as the Investigation of Stent grafts in patients with type B Aortic Dissection (INSTEAD), sponsored by Medtronic, investigate the chronic type so the inclusion criteria is after 14 days and up to one year. He went on to say that the first publication regarding acute treatment of dissection was not prospective randomised trials but was just comparative with the historical control open-surgery. “I think this is a very important study and I think it could be a breakthrough for endovascular treatment of acute dissections, even uncomplicated ones – the complicated ones are normally treated with stent grafts but the uncomplicated ones are not, so this is very important. Patient enrollment is due to commence in January 2007 and will be completed within one year. There will be interim results after another year, and a three year follow-up. The final results will are expected to be published in five years. “Moreover, we will obtain good information about the true follow-up of dissection and how the patients are doing with this medical treatment. There is actually no randomised trials on this issue and our primary goal of course is to see the effect of stent grafts, [and our] secondary goal is that we could get a good database,” concluded Brunkwall.