Helical stent having improved flexibility and expandability

A stent for insertion into a vessel of a patient, comprising:

• a tubular member having a first smaller diameter for insertion into the vessel, and a second larger diameter for deployment within the vessel,
• said tubular member including a central portion comprised of a plurality of helical circumferential windings separated by a helical space, each of said windings including a plurality of undulations, with each said undulation being defined by two adjacent struts and a loop connecting the struts,
• wherein adjacent windings are connected with a plurality of bridges, said bridges extending across said helical space between said adjacent winding and connected to said loops of a plurality of said undulations,
• wherein, for at least one of said windings, for any given number n of undulations on said winding and any given number b of bridges connected to said winding, where n≠b, a maximum number of undulations is provided between said bridges, and further including,
• a transition zone between said central portion and each of said cylindrical end portions, said transition zone including a plurality of transition undulations having struts that progressively increase in length,
• wherein a relatively longer strut of said transition undulations has a relatively wider width than a relatively shorter strut of said transition undulations.

A stent for insertion into a vessel of a patient, comprising:

• a tubular member having a first smaller diameter for insertion into the vessel, and a second larger diameter for deployment within the vessel, and defining a longitudinal axis, said tubular member including
• a central portion comprised of a plurality of helical circumferential windings separated by a helical space, each of said windings including a plurality of undulations, with each said undulation being defined by two adjacent struts and a loop connecting said struts,
• at least one cylindrical end portion at an end of said central portion, and
• a transition zone between said central portion and each of said cylindrical end portions, said transition zone including a plurality of transition undulations having struts that progressively increase in length,
• wherein a relatively longer strut of said transition undulations has a relatively wider width than a relatively shorter strut of said transition undulations.