Patent Description:
The invention relates generally to devices that are retained inside a body passage and in one particular application to vascular devices used in repairing arterial dilations, e.g., aneurysms. More particularly, the invention is directed toward devices that can be adjusted during deployment, thereby allowing at least one of a longitudinal or radial re-positioning of the device.

The invention will be discussed generally with respect to deployment of a bifurcated stent graft into the abdominal aorta but is not so limited and may apply to device deployment into other body lumens. When delivering a stent graft by intraluminal or endovascular methods, it is important to know the precise location of the device in the vasculature. Controlling this precise location is particularly important when the device is intended to be deployed in close proximity to branch vessels or adjacent to weakened portions of the aortic wall. Typical stent grafts used to repair an aortic aneurysm incorporate a proximal (i.e. portion of the stent graft closest to the heart) anchoring system intended to limit longitudinal displacement of the stent graft. Often this anchoring system must be precisely placed to avoid occlusion of a branch vessel or to avoid placement within a compromised and damaged portion of the aortic wall.

International Patent Application <CIT> to Xtent, Inc. discloses a device for controlling expandable prostheses, such as stents, during deployment.

The device comprises a stent, the expansion of which is controlled by the application of tension in control wires that are located at either side of the stent.

<CIT> discloses prosthesis delivery devices and methods that enable precise control of prosthesis position during deployment. Control mechanisms are provided in the prosthesis delivery devices that control either or both of the axial and rotational positions of the prostheses during deployment. This enables the deployment of multiple prostheses at a target site with precision and predictability, eliminating excessive spacing or overlap between prostheses.

A delivery system for such stent grafts that would provide a contribution over the prior art would include a means for allowing precise longitudinal and rotational placement of the stent graft and anchoring system. The precise position of the stent graft and anchoring system would be adjusted and visualized prior to full deployment of the device. Ideally the delivery system would allow the device to be repositioned if the prior deployment position was undesirable.

The present invention is directed to a controlled deployable medical device and method of making the same that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.

An embodiment of the present invention provides an apparatus, comprising a catheter having a proximal end portion and distal end portion. A hub can be arranged on a distal end portion of the catheter. A stent member is arranged on the proximal end portion of the catheter, the stent member has an inner surface and an outer surface. The stent can be configured in any suitable manner. In an embodiment of the invention, the stent is configured from multiple turns of an undulating element. Such a stent member can have substantially in-phase undulations. A graft member can be arranged about the stent member. Moreover, an element can be connected to a torsional member, wherein the torsional member is capable of retracting a portion of the element and thereby radially compressing at least a portion of the stent.

In another embodiment, the present invention provides an apparatus substantially as described above, further comprising a tube having a proximal end portion and distal end portion arranged on at least a portion of the substantially tubular shaped stent member, wherein at least a portion of the torsional member extends within a portion of the tube.

The accompanying drawings are included to provide a further understanding of the invention and illustrate certain aspects of the invention.

The invention relates generally to a medical apparatus that includes a device capable of being retained inside a body passage and in one particular application to vascular devices. More particularly, the invention is directed toward devices that can be adjusted during deployment, thereby allowing at least one of a longitudinal or radial re-positioning. The term distal as used herein denotes a position furthest from the heart, while the term proximal denotes a position closest to the heart.

In an embodiment of the invention, the medical apparatus includes a catheter assembly having a proximal end portion and distal end portion. A hub can be optionally arranged on a distal end portion of the catheter assembly. A stent is arranged on a proximal end portion of the catheter. A graft member can be arranged about at least a portion of the stent. The stent may be self-expandable, balloon-expandable or a combination of self-expandable and balloon-expandable.

In some embodiments, the stents can be used to fix the medical apparatus inside a portion of a patient's anatomy. The stent can be preferably constructed from materials that are flexible and strong. The stent can be formed from degradable bioabsorable materials, biodigestible materials, polymeric materials, metallic materials and combinations thereof. In addition, these materials may be reinforced and/or coated with other materials, such as polymeric materials and the like. The coating may be chosen to reduce acidic or basic effects of the gastrointestinal tract, e.g., with a thermoplastic coating such as ePTFE and the like.

More specifically, the stents can be fabricated according to the methods and materials as generally disclosed in, for example, <CIT>, <CIT> and <CIT> For example, stents can have various configurations as known in the art and can be fabricated, for example, from cut tubes, wound wires (or ribbons), flat patterned sheets rolled into a tubular form, combinations thereof, and the like. Stents can be formed from metallic, polymeric or natural materials and can comprise conventional medical grade materials such as nylon, polyacrylamide, polycarbonate, polyethylene, polyformaldehyde, polymethylmethacrylate, polypropylene, polytetrafluoroethylene, polytrifluorochlorethylene, polyvinylchloride, polyurethane, elastomeric organosilicon polymers; metals such as stainless steels, cobalt-chromium alloys and nitinol and biologically derived materials such as bovine arteries/veins, pericardium and collagen. Stents can also comprise bioresorbable materials such as poly(amino acids), poly(anhydrides), poly(caprolactones), poly(lactic/glycolic acid) polymers, poly(hydroxybutyrates) and poly(orthoesters).

The stents can be formed into a variety of different geometric configurations having constant and/or varied thickness as known in the art. The geometric configurations may include many conventional stent configurations such as a helically wrapped stent, z-shape stent, tapered stent, coil stent, combinations thereof, and the like. The stents can be formed in a variety of patterns, such as, a helix pattern, ring pattern, combinations thereof, and the like.

Grafts can have various configurations as known in the art and can be fabricated, for example, from tubes, sheets or films formed into tubular shapes, woven or knitted fibers or ribbons or combinations thereof. Graft materials can include, for example, conventional medical grade materials such as nylon, polyester, polyethylene, polypropylene, polytetrafluoroethylene, polyvinylchloride, polyurethane and elastomeric organosilicone polymers.

Stents can be used alone or in combination with graft materials. Stents can be configured on the external or internal surface of a graft or may be incorporated into the internal wall structure of a graft. Stent or stent grafts can be delivered endoluminally by various catheter based procedures known in the art. For example self-expanding endoluminal devices can be compressed and maintained in a constrained state by an external sheath. The sheath can be folded to form a tube positioned external to the compressed device. The sheath edges can be sewn together with a deployment cord that forms a "chain stitch". To release and deploy the constrained device, one end of the deployment cord can be pulled to disrupt the chain stitch, allowing the sheath edges to separate and release the constrained device. Constraining sheaths and deployment cord stitching can be configured to release a self-expanding device in several ways. For example a constraining sheath may release a device starting from the proximal device end, terminating at the distal device end. In other configurations the device may be released starting from the distal end. Self expanding devices may also be released from the device center as the sheath disrupts toward the device distal and proximal ends.

Details relating to constraining sheath materials, sheath methods of manufacture and stent graft compression techniques can be found in, for example, <CIT>, and <CIT>.

The catheter and hub assemblies can comprise conventional medical grade materials such as nylon, polyacrylamide, polycarbonate, polyethylene, polyformaldehyde, polymethylmethacrylate, polypropylene, polytetrafluoroethylene, polytrifluorochlorethylene, polyether block amide or thermoplastic copolyether, polyvinylchloride, polyurethane, elastomeric organosilicone polymers, and metals such as stainless steels and nitinol.

Turning to the figures, <FIG> is a medical apparatus according to an embodiment of the invention. <FIG> is an enlarged simplified view of a portion of the medical apparatus shown in <FIG>.

Referring to <FIG> and <FIG>, the medical apparatus is generally depicted as reference numeral 100A. The medical apparatus 100A includes catheter assembly <NUM>, stent <NUM> arranged on the proximal end portion of the catheter assembly <NUM>. The stent <NUM> has an inner surface, an outer surface, and is configured from multiple turns of an undulating element <NUM>. The undulating element <NUM> can be configured, for example, in a ring or helical pattern.

The stent <NUM> has a proximal end portion <NUM> and distal end portion <NUM>. The distal end portion <NUM> is formed into a branch having a first leg <NUM> and a second leg <NUM>.

A graft member <NUM> is arranged about the stent <NUM>.

In an embodiment of the invention, the stent <NUM> and graft member <NUM> are constrained into a compacted delivery state by a first sheath <NUM> and second sheath <NUM>. As shown in <FIG>, the first sheath <NUM> has been released allowing at least a portion of the stent <NUM> to expand as shown. The second sheath <NUM> is coupling the second leg <NUM> to the catheter assembly <NUM> as shown.

A torsional member <NUM> extends from a proximal end portion to a distal end portion of the catheter assembly <NUM>. In the figure, the torsional member <NUM> is positioned adjacent the outer surface of the stent <NUM> and graft <NUM>. The torsional member <NUM> is attached to the catheter assembly <NUM> and not attached to the stent <NUM> or graft <NUM>. A movable element <NUM> having a first end <NUM> and second end <NUM> surrounds the stent <NUM> and graft member <NUM>. The first end <NUM> and second end <NUM> of the movable element <NUM> extend out a distal end portion of the torsional member <NUM>. For example, the movable element <NUM> is threaded through the tube from a distal end to a proximal end and is looped around the proximal end portion <NUM> of the stent <NUM> and graft member <NUM>.

As shown in <FIG>, the torsional member <NUM> can be rotated in the direction shown by arrow <NUM>, tensioning the movable element <NUM> thereby causing at least a portion of the stent/graft to radial compress in the direction indicated by arrows <NUM>. The torsional member <NUM> can be configured with a side-wall aperture <NUM> through which the two ends <NUM>, <NUM> of the movable element <NUM> can be routed. The torsional member <NUM> can be rotated by turning the distal end of the tube <NUM>. The torsional member <NUM> can be rotated in the opposite direction (of that shown by arrow <NUM>) to allow the stent/graft to expand in the direction opposite of arrows <NUM>. The stent/graft can be compressed to allow rotational or longitudinal displacements within a vessel. When the desired placement is verified, the stent/graft can be allowed to expand and engage the vessel wall. Repeated compressions and expansions of the stent/graft can be utilized as desired. The stent/graft can also be gradually compressed or allowed to gradually expand by varying the amount of twist imparted to the torsional member <NUM>. After final placement of the stent/graft, tension can be applied to one of the ends <NUM>, <NUM> of the moveable element <NUM> to release and withdraw the movable element.

<FIG> is a medical apparatus according to an example, having a torsional member <NUM> positioned internal to the stent/graft.

Referring to <FIG>, the medical apparatus is generally depicted as reference numeral 100B. The medical apparatus of <FIG> is similar to the medical apparatus as shown in <FIG> and <FIG>. The medical apparatus includes a stent <NUM> and/or a graft <NUM> arranged on the proximal end portion of the catheter assembly.

A torsional member <NUM> extends from a proximal end portion to a distal end portion of the catheter assembly. The torsional member <NUM> is positioned internal to the stent <NUM> and graft <NUM>. The torsional member <NUM> is attached to the catheter assembly and not attached to the stent <NUM> or graft <NUM>. A movable element <NUM> having a first end <NUM> and second end <NUM> is looped through and around the stent <NUM> and graft member <NUM>. The first end <NUM> and second end <NUM> of the movable element <NUM> extend out a distal end portion of the torsional member <NUM>. For example, the movable element <NUM> is threaded through the tube from a distal end to a proximal end and is looped around the proximal end portion of the stent <NUM> and graft member <NUM>. As shown in <FIG>, the torsional member <NUM> can be rotated in the direction shown by arrow <NUM>, tensioning the movable element <NUM> thereby causing at least a portion of the stent/graft to radial compress in the direction indicated by arrows <NUM>. The torsional member <NUM> can be configured with a side-wall aperture <NUM> through which the two ends <NUM>, <NUM> of the movable element <NUM> can be routed. The torsional member <NUM> can be rotated by turning the distal end of the torsional member <NUM>. The torsional member <NUM> can be rotated in the opposite direction (of that shown by arrow <NUM>) to allow the stent/graft to expand in the direction opposite of arrows <NUM>. The stent/graft can be compressed to allow rotational or longitudinal displacements within a vessel. When the desired placement is verified, the stent/graft can be allowed to expand and engage the vessel wall. Repeated compressions and expansions of the stent/graft can be utilized as desired. The stent/graft can also be gradually compressed or allowed to gradually expand by varying the amount of twist imparted to the torsional member <NUM>. After final placement of the stent/graft, tension can be applied to one of the moveable ends <NUM>, <NUM> of the moveable element <NUM> to release and withdraw the movable element.

<FIG> are partial views of the proximal end of a medical apparatus according to a further embodiment of the invention, having releasable straps that can radial compress a stent/graft.

Referring to <FIG>, the medical apparatus is generally depicted as reference numeral <NUM>. The medical apparatus of <FIG> is similar to the medical apparatus as shown in <FIG> with a stent/graft not shown for clarity.

Shown in <FIG> is a partial cross-section of a distal end of a catheter system <NUM> having an outer tube <NUM>. Contained within the outer tube <NUM> are a first inner tube <NUM> and a torsional member <NUM>. Attached to the torsional member is at least one flexible strap <NUM>. The flexible strap <NUM> surrounds a distal portion of a stent/graft (not shown). When the torsional member <NUM> is rotated as depicted by arrow <NUM> the strap <NUM> is further wound around the torsional member <NUM>, thereby "drawing in" the strap which will in turn, compress a surrounded stent/graft. The degree of stent/graft compression can be controlled by varying the amount of twist imparted to the torsional member. A first end <NUM> of a flexible strap <NUM> can be affixed to the torsional member <NUM>. The second end <NUM> of the strap <NUM> can be wrapped around the torsional member. When the medical apparatus is properly positioned with a target site, the torsional member can be rotated in a direction opposite that shown by arrow <NUM>. This opposite rotation will allow the stent/graft to fully expand. Further opposite rotation of the torsional member will cause the strap end <NUM> to "un-wind" from the torsional member. The torsional member can then be withdrawn in a distal direction, pulling the strap with attached end <NUM> into the first inner tube. In an alternate method the first inner tube and the torsional member can be withdrawn together or all three members (<NUM>, <NUM>, <NUM>) can be withdrawn together.

Shown in <FIG> is a non cross-sectional perspective view of the distal end of the catheter system shown in <FIG>. The flexible straps <NUM> can be fabricated from various bio-compatible materials as commonly known in the art.

<FIG> and <FIG> are partial perspective views of a medical apparatus according to a further embodiment of the invention.

Referring to <FIG> and <FIG>, the medical apparatus is generally depicted as reference numeral 300A or 300B. The medical apparatus 300A and B includes catheter assembly <NUM>, stent <NUM> arranged on the proximal end portion of the catheter assembly <NUM>. The stent <NUM> has an inner surface, an outer surface, and is configured from multiple turns of an undulating element <NUM>. The undulating element <NUM> can be configured, for example, in a ring or helical pattern.

The stent <NUM> and graft member <NUM> are constrained into a compacted delivery state by a first sheath <NUM> and second sheath <NUM>. As shown in <FIG> and <FIG>, the first sheath <NUM> has been released allowing at least a portion of the stent <NUM> to expand as shown. The second sheath <NUM> is coupling the second leg <NUM> to the catheter assembly <NUM> as shown.

Shown in <FIG> is a flexible constraining sleeve <NUM>, surrounding a proximal portion of the stent/graft. A torsional member <NUM> extends from a proximal end portion to a distal end portion of the catheter assembly <NUM>. In the figure, the torsional member <NUM> is positioned adjacent the outer surface of the stent <NUM> and graft <NUM>. The torsional member <NUM> is attached to the catheter assembly <NUM> and not attached to the stent <NUM> or graft <NUM>. The flexible sleeve <NUM> is attached to the torsional member <NUM> so that when the torsional member <NUM> is rotated, the flexible sleeve is compressed which in turn compresses the stent/graft. The flexible sleeve <NUM> is shown having a parting or rip cord <NUM>. The rip cord <NUM> can be in the form of a thread or wire that is contained within a secondary tube <NUM>. The secondary tube <NUM> can exit the distal end of the catheter assembly <NUM> with the rip cord exiting the distal end of the secondary tube. When the medical apparatus is properly deployed the distal end of the rip cord can be tensioned, thereby ripping or separating the flexible sleeve <NUM>. Since the flexible sleeve is still attached to the torsional member <NUM>, the flexible sleeve <NUM> can then be withdrawn along with the catheter assembly <NUM>.

Shown in <FIG> is a flexible constraining sleeve <NUM>, surrounding a proximal portion of the stent/graft. A torsional member <NUM> extends from a proximal end portion to a distal end portion of the catheter assembly <NUM>. In the figure, the torsional member <NUM> is positioned adjacent the outer surface of the stent <NUM> and graft <NUM>. The torsional member <NUM> is attached to the catheter assembly <NUM> and not attached to the stent <NUM> or graft <NUM>. The flexible sleeve <NUM> is attached to the torsional member <NUM> so that when the torsional member <NUM> is rotated, the flexible sleeve is compressed which in turn compresses the stent/graft. The flexible sleeve <NUM> is shown having a parting line <NUM>. Shown is a stitched parting line <NUM> similar to those parting lines incorporated into the first <NUM> and second <NUM> sheaths. The release of the stitched parting line <NUM> can be activated by a release cord <NUM>. The release cord <NUM> can be in the form of a thread or wire and can be contained within a secondary tube (not shown) or be contained within a catheter system lumen. The release cord <NUM> can exit the distal end of the catheter assembly <NUM>. When the medical apparatus is properly deployed the distal end of the release cord <NUM> can be tensioned, thereby un-stitching or separating the flexible sleeve <NUM>. Since the flexible sleeve is still attached to the torsional member <NUM>, the flexible sleeve <NUM> can then be withdrawn along with the catheter assembly <NUM>.

Claim 1:
An apparatus (100A), comprising:
a catheter (<NUM>) having a proximal end portion and distal end portion;
a stent (<NUM>) arranged on the proximal end portion of the catheter, the stent having an inner surface and an outer surface;
a graft member (<NUM>) arranged about the stent (<NUM>) member;
a movable element (<NUM>) surrounding a portion of the stent (<NUM>) and a portion of the graft member (<NUM>) and the movable element (<NUM>) includes a first end (<NUM>) and a second end (<NUM>); and
a rotatable torsional member (<NUM>) positioned adjacent the outer surface of the stent (<NUM>) and the graft member (<NUM>) connected to the movable element (<NUM>), and configured to rotate in a first direction to allow for retracting a portion of the movable element (<NUM>) in order to radially compress at least a portion of the stent (<NUM>), and configured to rotate in a second opposite direction to allow for expanding the movable element (<NUM>) to allow for withdrawal of the movable element (<NUM>) from the stent (<NUM>), wherein the first end (<NUM>) and the second end (<NUM>) of the movable element (<NUM>) extend out a distal end portion of the rotatable torsional member (<NUM>).