Steep-taper flared stents and apparatus and methods for delivering them

A stent comprising a tubular member including first and second ends defining a longitudinal axis therebetween and a plurality of circumferential bands disposed between the first and second ends, the tubular member being expandable from a contracted condition to an enlarged condition through an intermediate condition, the stent comprising:

• a first end portion that flares outwardly when the tubular member is expanded from the contracted condition to the intermediate condition, the first end portion comprising a first band at the first end and a second band connected to the first band, the first and second bands comprising axial segments extending substantially parallel to the longitudinal axis and connected by curved segments in the contracted condition;
• a second portion adjacent the first portion;
• and
• a plurality of connectors extending from the second portion to the second band of the first end portion, the connectors being relatively flexible compared to the axial segments and curved segments of the first and second bands such that the axial segments of the second band assume a generally radially outward orientation in the intermediate condition;
• wherein the curved segments of the first band bend to cause the axial segments of the first band to assume a substantially enclosed generally circumferential orientation defining the first end of the stent in the enlarged condition.

An apparatus for treating an ostium communicating between a main body lumen and a branch body lumen, comprising:

• an elongate member comprising a proximal end, a distal end sized for introduction into the main body lumen and the branch body lumen, and defining a longitudinal axis therebetween;
• an expandable member on the distal end, the expandable member being expandable from a first collapsed configuration to a second flared configuration, and a third expanded configuration;
• and
• a stent on the distal end over the expandable member, the stent comprising a first end portion and a second portion connected to the first end portion by a plurality of flexible connectors, the first end portion comprising first and second circumferential bands, each band including alternating axial segments, extending substantially parallel to the longitudinal axis in the contracted configuration, and curved segments defining a serpentine pattern and coupled together such that, upon expansion to an intermediate condition, first axial segments of the first band are directed to a generally radially outward orientation and, upon expansion to an enlarged condition, the first axial segments are directed to a substantially enclosed generally circumferential orientation and second axial segments of the second band are directed to a generally transverse orientation;
• wherein, when the expandable member is expanded to the second configuration, the first end portion of the stent is expanded to the intermediate condition while the second portion remains unexpanded, and when the expandable member is expanded to the third configuration, the second portion is expanded radially outwardly and the first end portion is further expanded radially outwardly to the enlarged condition.

An apparatus for treating an ostium communicating between a main body lumen and a branch body lumen, comprising:

• an elongate member comprising a proximal end, a distal end sized for introduction into the main body lumen and the branch body lumen, and defining a longitudinal axis therebetween, and an expandable member on the distal end, the expandable member being expandable from a first collapsed configuration to a second flared configuration and a third expanded configuration;
• and
• a stent on the distal end over the expandable member, the stent comprising a first end portion and a second portion connected to the first end portion by a plurality of flexible connectors, the first end portion comprising first and second circumferential bands, the first band defining a first end of the stent and the second band connected to the first band and the flexible connectors, each band comprising a serpentine pattern of axial elements alternately connected to curved elements extending around a circumference of the stent, the curved segments having a lower yield strength than the axial elements, adjacent curved elements of the first and second bands connected to one another, the axial elements of the first band directed from a generally axial orientation extending substantially parallel to the longitudinal axis towards a generally radially outward orientation when the expandable member is expanded from the first configuration to the second configuration and directed from the generally radially outward orientation towards a substantially enclosed circumferential orientation when the expandable member is expanded to the third configuration, the axial elements of the second band being directed from a generally axial orientation extending substantially parallel to the longitudinal axis towards a generally radially outward orientation when the expandable member is expanded from the first configuration to the second configuration, the second portion being expanded radially outwardly when the expandable member is expanded from the second configuration to the third configuration.

A stent comprising a tubular member including first and second ends defining a longitudinal axis therebetween, the tubular member being expandable from a contracted condition to an enlarged condition through an intermediate condition, the stent comprising:

• a first end portion that flares outwardly when the tubular member is expanded from the contracted condition to the intermediate condition, the first end portion comprising a first circumferential band at the first end and a second circumferential band connected to the first band, each band comprising a serpentine pattern of axial elements alternately connected to curved elements extending around a circumference of the stent, the curved segments having a lower yield strength than the axial elements, adjacent curved elements of the first and second bands connected to one another, the axial elements of the first band directed from a generally axial orientation extending substantially parallel to the longitudinal axis towards a generally radially outward orientation when expanded from the contracted condition to the intermediate condition and directed from the generally radially outward orientation towards a substantially enclosed circumferential orientation when expanded from the intermediate condition to the enlarged condition, the axial elements of the second band directed from a generally axial orientation extending substantially parallel to the longitudinal axis towards a generally radially outward orientation when expanded from the contracted condition to the intermediate condition;
• a second portion adjacent the first end portion and expandable radially outwardly;
• and
• a plurality of connectors connecting the second portion to the second band of the first end portion, the connectors being relatively flexible compared to the axial elements and curved segments of the first and second bands to accommodate the axial elements of the second band being directed to the generally radially outward orientation.