The present disclosure relates generally to medical devices for implantation within a human or animal body for repair of damaged vessels, ducts, or other physiological pathways, and particularly, to prostheses with side branch lumens.
Endovascular methods have been proposed for treatment of diseases of the aorta such as aortic dissection and aortic aneurysm. Using prostheses, such as stent grafts, to treat aneurysms is common in the medical field. Stent grafts are deployed by accessing a vasculature with a small incision in the skin and guiding a delivery system to the target area. This endoluminal delivery is less invasive and generally preferred over more intrusive forms of surgery. Multiple stent grafts may be implanted using endoluminal delivery to provide a system of interconnected stent grafts. Interconnected stent grafts can be made of fenestrated stent grafts and smaller side branch grafts, including bifurcated components.
Such methods have been proposed particularly when the diseased portion of the aorta is adjacent the aorta bifurcation. But when the diseased portion of the aorta is located higher up in the aorta, for example, in the region of the descending aorta adjacent the thoracic arch or in the ascending aorta, endovascular techniques for treating these diseases are somewhat more difficult because of the arched or curved nature of the thoracic arch, the presence of major arteries in the region, and the proximity to the heart.
For instance, for treatment of thoracic aortic aneurysms and/or dissections in particular, it is necessary to introduce the stent graft high up in the aorta and in a region of the aorta which is curved and where there can be strong blood flow. Furthermore, in the thoracic aorta there are major branch vessels extending therefrom, such as the brachiocephalic, carotid and/or subclavian arteries. During and/or after treatment of an aneurysm or dissection in the region of the thoracic arch, it is desirable for blood supply to continue to flow to these branch arteries. For this purpose, fenestrations or side branches are provided in a stent graft that is placed in that region, through which side arms or branch extensions may be deployed and extend into the brachiocephalic, carotid and/or subclavian arteries, for example.
Custom made devices, including scalloped and fenestrated devices, have been used in situations where the arch vessels are compromised and entire coverage of the aortic arch is not required. However, deployment of these devices may be difficult.