An implantable device to be disposed within a body lumen, the implantable device comprising: a scaffolding structure defining a generally cylindrical shape and a lumen through the scaffolding structure, wherein a first portion (γ) of the scaffolding structure comprises a lattice structure formed by a plurality of interconnected arms arranged to form quadrilateral-shaped cells, the scaffolding structure having a second portion (α); and a valve coupled to an inside diameter of the scaffolding structure; wherein the second portion (α) of the scaffolding structure comprises a second plurality of interconnected arms with adjacent arms arranged at acute angles relative to each other in rows around a longitudinal axis (A L) of the cylindrical shape, the rows arranged in the longitudinal direction of the cylindrical shape, wherein the rows are connected to each other by a plurality of connectors extending in the longitudinal direction of the cylindrical shape, wherein the rows of the second plurality of interconnected arms and the plurality of connectors in the second portion (α) form cells that are non-quadrilateral in shape; the first portion (γ) extends longitudinally from a distal end of the scaffolding structure to an intermediate location on the scaffolding structure and the second portion (α) extends longitudinally from the intermediate location on the scaffolding structure to a proximal end of the scaffolding structure; characterized in that, the valve is coupled to the first portion (γ) of the scaffolding structure; and the first portion (γ) of the scaffolding structure is stiffer than the second portion (α) of the scaffolding structure. a scaffolding structure defining a generally cylindrical shape and a lumen through the scaffolding structure, wherein a first portion (γ) of the scaffolding structure comprises a lattice structure formed by a plurality of interconnected arms arranged to form quadrilateral-shaped cells, the scaffolding structure having a second portion (α); and a valve coupled to an inside diameter of the scaffolding structure; wherein the second portion (α) of the scaffolding structure comprises a second plurality of interconnected arms with adjacent arms arranged at acute angles relative to each other in rows around a longitudinal axis (A L) of the cylindrical shape, the rows arranged in the longitudinal direction of the cylindrical shape, wherein the rows are connected to each other by a plurality of connectors extending in the longitudinal direction of the cylindrical shape, wherein the rows of the second plurality of interconnected arms and the plurality of connectors in the second portion (α) form cells that are non-quadrilateral in shape; the first portion (γ) extends longitudinally from a distal end of the scaffolding structure to an intermediate location on the scaffolding structure and the second portion (α) extends longitudinally from the intermediate location on the scaffolding structure to a proximal end of the scaffolding structure; characterized in that, the valve is coupled to the first portion (γ) of the scaffolding structure; and the first portion (γ) of the scaffolding structure is stiffer than the second portion (α) of the scaffolding structure.