E‑vita open plus for treating complex aneurysms and dissections of the thoracic aorta

The E‑vita open plus (JOTEC GmbH) is an endoluminal stent graft system designed for treating aneurysms and dissections of the thoracic aorta. The device is a 1-piece polyester fabric tube which combines a conventional vascular graft attached to an endovascular stent graft that allows treatment of the ascending aorta at the same time as the arch and descending aorta. The E‑vita open plus supersedes its immediate predecessor device, the E‑vita open. The 2 devices are similar in design and function but the E‑vita open plus is impermeable to blood, and fibrin glue is not needed to seal the stent graft.

The E‑vita open plus is a single-use device with a shelf life of 2 years. It is supplied sterile and pre-loaded in its delivery system. The device is available in a range of sizes with varying diameters and lengths. The delivery system consists of a release handle, nested catheters and a positioning aid. A luer connector is also incorporated to allow flushing of the inner guide catheter. A stiff guide wire is used to aid tracking of the device delivery. Radiopaque markers are integrated into the fabric of the graft for radiological imaging.

The E‑vita open plus received a CE mark in October 2008 for the repair or replacement of the thoracic aorta in cases of complex aneurysms or dissections that involve the ascending aorta, the aortic arch and the descending aorta.

The E‑vita open plus is used in a single-stage procedure known as a 'frozen elephant trunk'. The thoracic aorta is surgically opened with access through a median sternotomy approach. The distal stent graft portion of the device is self-expanding, containing nitinol springs, and is used to treat the upper part of the descending aorta. The vascular graft part of the device (for repair of the arch and ascending aorta) is invaginated in the distal stent graft portion. The stent graft, in its delivery system, is inserted into the descending aorta and deployed by retracting a retaining sheath. Once the stent graft is in place, the delivery system is removed and the proximal vascular graft component is drawn out a short distance (5 mm to 10 mm). The stent graft is then surgically anastomosed to the distal aorta. The vascular graft portion of the device is then drawn out fully and used to repair the ascending aorta and arch in a standard surgical fashion. The aortic branch vessels are attached to the vascular graft using a patch and the graft is anastomosed to the ascending aorta.

The cost of the E‑vita open plus stated in the sponsor's submission was £10,500 excluding VAT.

The claimed benefits of the E‑vita open plus in the case for adoption presented by the sponsor are:

• repair of the ascending aorta, arch and descending aorta in a single-stage procedure

• a reduction in pain and discomfort

• elimination of the psychological distress associated with the anticipation of a second procedure

• a reduction in treatment times and costs

• a reduction in total end-organ ischaemia

• a reduction in incisional complications and infections

• a reduction in anaesthetic use and the elimination of the need for additional epidural pain management

• a reduction in both total length of stay and intensive care unit length of stay

• a reduction in rehabilitation time

• an earlier return to normal activities and work.

The management of thoracic aortic aneurysms and dissections is determined by the location, severity and rate of change of the disease, as well as the clinical circumstances. Thoracic aortic aneurysms result from a weakening of the aortic wall, leading to localised dilation. People with thoracic aneurysms are often observed with clinical and imaging surveillance. Invasive treatment may be offered depending upon the size and rate of enlargement of the aneurysm.

Aortic dissections result from a tear in the inner layer of the aorta. Blood flows through the tear, separating the layers of the wall. Acute aortic dissections are less than 2 weeks old, and chronic dissections have been present for longer than 2 weeks. Management of aortic dissections depends primarily on their location. Emergency surgery is usually offered for a Stanford type A aortic dissection, which affects the ascending thoracic aorta and often also the arch and descending aorta. Stanford type B dissections, typically involving the descending thoracic aorta, are often managed with conservative medical treatment. Elective surgical repair is sometimes undertaken, but endovascular repair with stent grafts is more commonly used.

There are 3 main current methods of surgically treating complex aneurysms and dissections of the thoracic aorta, 2 of which involve a 2-stage 'elephant trunk' procedure. Both approaches are similar in their first stage but use alternative repair techniques to complete the second stage. During the first stage, the ascending aorta and arch are repaired with a vascular graft through a median sternotomy. During this procedure a free-floating extension of the arch graft prosthesis (the 'elephant trunk') is left unattached in the descending aorta. Attaching it (and extending it as necessary) may be done by an endovascular procedure during which a stent graft is inserted into the descending aorta with access via the femoral artery (thoracic endovascular aortic repair – TEVAR). Alternatively the descending aorta may be repaired in a second surgical procedure some weeks or months later, by extending the 'elephant trunk' as necessary, through a lateral thoracotomy approach. The third method involves 'debranching' of the head and neck vessels from the aortic arch by creating a surgical anastomosis between the ascending aorta and the head and neck vessels using a vascular graft. This then allows an endoluminal stent graft to be inserted into the aortic arch and descending aorta either as a hybrid procedure (during the same operation) or at a second-stage operation.