Patent ID: 8715340

Claim:
An endovascular device for insertion into a body vessel to treat an aneurysmal portion of the body vessel, the endovascular device comprising: an expandable member, expandable from a first position to a second position, said expandable member being expandable radially outwardly to the second position such that an outer surface of said expandable member is configured to engage an inner surface of the vessel so as to maintain a fluid pathway in said vessel through a lumen in the expandable member, the expandable member comprising a plurality of struts that define a wall having an exterior surface and an interior surface; a membrane, comprising an expandable polymer film, covering at least a portion of an outer surface of said expandable member, the membrane extending continuously around and between each of the plurality of struts and having a portion extending (i) continuously from a first of the plurality of struts to a strut adjacent to the first strut, and (ii) entirely between the exterior surface and the interior surface; wherein the portion of the membrane contacts the first of the plurality of struts and the adjacent strut and resides entirely within a space bounded by the first of the plurality of struts, the adjacent strut, the exterior surface, and the interior surface; and a plurality of pores in a porous section of the membrane, the porous section (a) extending from a proximal end to a distal end of the expandable polymer film, and (b) having a substantially uniform porosity over a length extending from a proximal end to a distal end of the porous section, porosity being determined by a pore spacing and a pore size, the pore spacing being a distance between adjacent pores of the plurality of pores, and the pore spacing being less than about 100 μm in the first position; wherein the ratio of (a) the area of only membrane material at an outer surface of the porous section, to (b) a total area of the outer surface, including the area of the pores, defines a material ratio of 70% to 80% in the second position; wherein, when the expandable member is positioned in the body vessel, the substantially uniform porosity of the membrane permits a flow of blood from within the lumen of the expandable member, through at least one of the pores, and into at least one branch vessel that branches off of the body vessel; and wherein, when the expandable member is positioned in the body vessel, the substantially uniform porosity of the membrane reduces blood flow to the aneurysmal portion of the vessel, promoting thrombosis at or in the aneurysmal portion.