This disclosure relates generally to a stent having a high expansion ratio and, more particularly, to a stent including a frame that is movable between a collapsed configuration and an expanded configuration to treat a bifurcation.
Support structures that are collapsible but yet provide adequate strength and/or stiffness, particularly in a radial direction, are desirable when positioned within relatively small spaces. It is also desirable that such support structures are expandable to a deployed configuration greater than a collapsible, insertion configuration. Such support structures are useful in medical applications including, without limitation, implantation of luminal stents within a patient's vasculature.
Stents are generally utilized to support living tissues, such as a body lumen. For example, stents may be used to radially support a collapsing or occluded blood vessel or to treat an aneurysm within a blood vessel. Conventional stents typically form an elongated tube or wire frame that provides structural support for the vessel wall. Further, a tubular graft may be positioned about or within the stent to facilitate blood flow through the blood vessel while preventing undesirable blood flow into the aneurysm.
Many conventional stents are positioned in a collapsed, insertion configuration within a delivery system including a catheter to deliver the stent to a lesion site within the body lumen. With the stent properly positioned with respect to the lesion site, the stent is disengaged from the catheter and urged to expand to a deployed configuration.
In another aspect, an expandable frame is provided. The expandable frame includes a first member including a plurality of substantially parallel first struts and a plurality of substantially parallel second struts with the frame in a collapsed configuration. Each second strut of the plurality of second struts is coupled between adjacent first struts of the plurality of first struts defining a plurality of open cells to facilitate expansion of the frame towards an expanded configuration. At least one second member is coupled to the first member. The at least one second member includes a plurality of third struts. Each third strut of the plurality of third struts is coupled to adjacent third struts at an acute angle with the frame in the collapsed configuration.
In another aspect, a stent is provided. The stent includes an expandable frame. The expandable frame includes a first member including a plurality of substantially parallel first struts and a plurality of substantially parallel second struts with the frame in a collapsed configuration. Each second strut of the plurality of second struts is coupled between adjacent first struts of the plurality of first struts defining a plurality of open cells to facilitate expansion of the frame towards an expanded configuration. At least one second member is coupled between a first point on the first member and a second point on the first member.
In another aspect, an expandable frame is provided. The expandable frame includes a first member including a plurality of first struts. Each first strut is coupled to adjacent first struts at an acute angle with the frame in a collapsed configuration to define a plurality of open cells to facilitate expansion of the frame towards an expanded configuration. At least one second member is coupled to the first member. The at least one second member includes a plurality of second struts. Each second strut is coupled to adjacent second struts at an acute angle with the frame in the collapsed configuration.
In another aspect, a stent is provided. The stent includes a first segment having a first expansion ratio, and a second segment having a second expansion ratio. The first segment and/or the second segment is radially expandable to form an opening at least partially defined within a body wall of the stent.
The present disclosure provides a device, such as a stent, having a high expansion ratio to facilitate properly positioning the device in a collapsed, insertion configuration within a space and/or expanding the device within the space to an expanded, deployed configuration. Although the present disclosure is described below in reference to its application in connection with a stent that is positioned within a body lumen to support and/or treat a portion of the body lumen, it should be apparent to those skilled in the art and guided by the teachings herein provided that the disclosure is likewise applicable for use with any suitable device or component, including any suitable device or component that is implanted within a patient's body.
Referring to
Frame 12 is fabricated of a biocompatible material including, without limitation, suitable metal materials, such as stainless steel, platinum, gold, titanium and nickel and/or composites or alloys thereof. In the exemplary embodiment, frame 12 is fabricated at least partially from a material having shape memory properties. Suitable materials include, without limitation, Nitinol and other known shape memory alloys (SMA) having properties that develop a shape memory effect (SME), which allows the material to return to an initial configuration after a force applied to the material to shape, stretch, compress and/or deform the material is removed. In a further embodiment, frame 12 is fabricated from a thermally treated metal alloy (TMA) including, without limitation, nickel titanium, beta titanium, copper nickel titanium and any combination thereof. In one embodiment, frame 12 is expandable using a balloon and/or another mechanism suitable for facilitating expanding frame 12. In an alternative embodiment, frame 12 is fabricated at least partially from a suitable polymeric material, such as a polyurethane material. It should be apparent to those skilled in the art and guided by the teachings herein provided that frame 12 may be made or fabricated using any suitable biocompatible material preferably, but not necessarily, having suitable shape memory properties.
Frame 12 includes at least one first member 14. In one embodiment as shown in
First member 14 includes a plurality of first struts 24 (not shown in
Second struts 26 are coupled between adjacent first struts 24 to facilitate expansion of frame 12 towards an expanded configuration, such as shown in
Referring further to
In alternative embodiments, stent 10 includes a plurality of cells 50, as shown in
Cells 50 and/or the selected areas or segments of high expansion ratio facilitate fabricating stent 10 having selected areas or segments with different expansion ratios. As a result, stent 10 is fabricated in a suitable configuration having a suitable shape and/or suitable dimensions for an anticipated procedure. For example, stent 10 may have one or more areas or segments having an irregular shape with protrusions, invaginations and/or branches 52, as shown in
In one embodiment, a catheter 60 is utilized to facilitate properly positioning stent 10 within a body lumen. Catheter 60 includes at least one balloon 62 that is inflatable to expand stent 10 once properly positioned within the body lumen. Balloon 62 is configured to inflate to a desired shape, such as shown in
Referring to
Referring further to
In a further alternative embodiment, stent 10 includes two substantially similar segments 82, 84. In a particular embodiment, segments 82, 84 are coupled together at a transition line. With catheter 60 properly positioned within the body lumen, balloons 62, 64, 66 are inflated to provide a suitable opening 92 at or near an area where segment 82 meets or transitions into segment 84, such as along the transition line. As balloon 64 is inflated to radially expand segment 82 and/or segment 84, opening 92 is formed to provide flow communication through opening 92. After stent 10 is properly positioned within the body lumen, catheter 60, including balloons 62, 64, 66, is removed from within the body lumen. Alternatively, the system may include two separate stents 10 positioned on catheter 60. The stents 10 may be coupled to each other or may be separate from each other.
The above-described device, such as a stent, has a high expansion ratio to facilitate accurately positioning the device in a collapsed or compressed configuration within a body lumen and to provide sufficient support to the body lumen upon expansion of the device to an expanded configuration within the body lumen. More specifically, the device includes an expandable frame that is movable between a collapsed, insertion configuration and an expanded, deployed configuration to facilitate providing a high expansion ratio for the device.
Exemplary embodiments of a device having a high expansion ratio are described above in detail. The device is not limited to the specific embodiments described herein, but rather, components of the device may be utilized independently and separately from other components described herein. Further, the described device can also be defined in, or used in combination with, other devices and/or methods, and are not limited to practice with only the device as described herein.
This application is a divisional of U.S. patent application Ser. No. 15/131,893 filed on Apr. 18, 2016, which was a continuation of U.S. patent application Ser. No. 11/809,955 filed on Jun. 4, 2007.
Number | Date | Country | |
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Parent | 15131893 | Apr 2016 | US |
Child | 17060874 | US |
Number | Date | Country | |
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Parent | 11809955 | Jun 2007 | US |
Child | 15131893 | US |