News Column

"Lock/Floating Marker Band on Pusher Wire for Self-Expanding Stents Or Medical Devices" in Patent Application Approval Process

September 11, 2014



By a News Reporter-Staff News Editor at Politics & Government Week -- A patent application by the inventors Young, Eugene (Union City, CA); Yeh, Chung Hao (Victorville, CA); Ken, Christopher G.M. (San Mateo, CA); Ho, Thu Anh (San Jose, CA), filed on March 21, 2014, was made available online on August 28, 2014, according to news reporting originating from Washington, D.C., by VerticalNews correspondents.

This patent application is assigned to Depuy Synthes Products, Llc.

The following quote was obtained by the news editors from the background information supplied by the inventors: "The present application relates to systems for deploying and/or retrieving intravascular stents, and more particularly relates to an apparatus for deploying and/or retrieving a self-expanding intravascular stent or medical device, including an intravascular stent delivery wire or pusher wire having one or more floating marker bands movably retained or constrained over the intravascular stent delivery wire or pusher wire for delivery and retrieval of an intravascular stent releasably placed over the one or more floating marker bands.

"Intravascular stents are generally tubular and are actively or passively expanded radially in the vasculature of a patient. Such stents can be mounted over an expandable member or balloon of a balloon angioplasty catheter, for deployment of the stents by expansion of the balloon at the treatment site of the vasculature, such as at a stenosis or an aneurysm. Self-expanding stents can expand from a compressed delivery position to a larger diameter without the assistance of an expandable member or balloon.

"Intravascular stent delivery systems for placement of an intravascular self-expanding stent at a treatment site in the vasculature typically have included a catheter that can be threaded through the vasculature with the self-expanding stent axially placed over a distal portion of the catheter. To position an intravascular stent at the treatment site of the vasculature, such as at a stenosis or an aneurysm, a guiding catheter is typically introduced into the vascular system of a patient, and advanced within the vasculature until the distal tip of the guiding catheter is adjacent to the treatment site. A guidewire is typically then advanced through the guiding catheter to the desired location, and then a dilatation or delivery catheter having a stent positioned on the dilatation or delivery catheter is advanced into the patient's vasculature over the guidewire, until the stent is properly positioned, after which the stent can be deployed at the treatment site.

"One common technique for maintaining a self-expanding stent in a low profile configuration involves placement of a sheath or a sleeve over some or all of the stent, typically either to retain the stent in a compressed configuration around the catheter, to prevent body fluids from reaching the stent, or to protect the vasculature from the stent. Usually such a sheath or sleeve is retracted or released from the stent to allow the stent to achieve an expanded configuration.

"A guidewire loaded stent is also known in which a radially expandable stent carried on a guidewire is covered in part by a retractable restraining sheath at or near a distal end of the guidewire. When the stent is placed at a treatment site, the restraining sheath is retracted to expose the stent and thus allow the stent to expand.

"It would be desirable to provide an intravascular stent delivery system, including an intravascular stent delivery wire or pusher wire having one or more floating marker bands movably retained or constrained over the intravascular stent delivery wire or pusher wire for delivery and retrieval of a self-expanding intravascular stent or medical device releasably placed over the one or more floating marker bands, in order to provide a reduced diameter profile to permit delivery of an intravascular stent to smaller diameter and more delicate vessels of the vasculature, such as the neurovasculature.

"It would also be desirable to provide an intravascular stent delivery wire or pusher wire having one or more floating marker bands movably retained or constrained over the intravascular stent delivery wire or pusher wire to allow for an integration of a proximal or distal segment of a self-expanding intravascular stent or medical device with the intravascular stent delivery wire or pusher wire to be fit into a catheter or tubular sheath and advanced and retracted within the catheter, within the vasculature of a patient, and to allow for the self-expanding intravascular stent or medical device to be retrieved back into the catheter after partial stent deployment.

"It would also be desirable to provide an intravascular stent delivery wire or pusher wire having one or more floating marker bands movably retained or constrained over the intravascular stent delivery wire or pusher wire with a self-adjusting, variable gap between the self-expanding intravascular stent or medical device and a fixed marker band fixedly mounted on the intravascular stent delivery wire or pusher wire, in order to facilitate ease of advancement or retraction of the assembly and to allow for improved articulation of the self-expanding intravascular stent or medical device with respect to the intravascular stent delivery wire or pusher wire in a narrow vascular curvature which would otherwise not allow for traversing of the curve with conventional systems.

"It also would be desirable to provide an intravascular stent delivery system including an intravascular stent delivery wire or pusher wire having one or more floating marker bands movably retained or constrained over the intravascular stent delivery wire or pusher wire for delivery and retrieval of an intravascular stent releasably placed over the one or more floating marker bands, so that the intravascular stent delivery wire or pusher wire tip is free to rotate during system advancement, for ease of navigating tortuous vascular anatomy.

"It also would be desirable to provide an intravascular stent delivery system including an intravascular stent delivery wire or pusher wire with one or more floating marker bands having an outside circumference with a multi-sided or polygon shape, such as a square shape or pentagonal shape, for example, to allow for struts, legs or radiopaque markers of the self-expanding intravascular stent or medical device to extend beyond the one or more floating marker bands so that the struts, legs or radiopaque markers of the self-expanding intravascular stent or medical device are constrained by the catheter or tube wall and by one or more sides of the one or more floating marker bands, to allow for the self-expanding intravascular stent or medical device to interface with the intravascular stent delivery wire or pusher wire, and to allow the self-expanding intravascular stent or medical device to maintain column strength not to buckle under compression loads, particularly so that the self-expanding intravascular stent or medical device can be retrieved under tensile loads.

"It also would be desirable to provide an intravascular stent delivery system including an intravascular stent delivery wire or pusher wire with one or more floating marker bands that can be located under the body of the self-expanding intravascular stent or medical device to provide support for the self-expanding intravascular stent or medical device, and to prevent or minimize stent buckling of the self-expanding intravascular stent or medical device. The present invention meets these and other needs."

In addition to the background information obtained for this patent application, VerticalNews journalists also obtained the inventors' summary information for this patent application: "Briefly and in general terms, the present invention provides for an apparatus for deploying and/or retrieving a self-expanding intravascular stent or medical device, including an intravascular delivery wire and one or more floating marker bands movably retained or constrained over the intravascular stent delivery wire or pusher wire, and configured to releasably mount a self-expanding intravascular stent or medical device on the one or more floating marker bands. In a presently preferred aspect, the outside circumference of the lock/floating marker band(s) has a multi-sided or polygon shape, such as a square shape or pentagonal shape, for example. In another presently preferred aspect, the intravascular stent delivery wire or pusher wire tip is free to rotate during system advancement for ease of navigating tortuous vascular anatomy.

"In another presently preferred aspect, the one or more floating marker bands can be movably retained or constrained to a fixed marker band such as by a coil spring, braid or wire, for example, which can be connected to a ring or laser indentation on the fixed marker band, for example. The fixed marker band is fixedly attached to the intravascular stent delivery wire or pusher wire. Alternatively, the one or more floating marker bands can be movably retained or constrained to the intravascular stent delivery wire or pusher wire, such as by a coil spring, braid or wire, for example, which can be connected to a ring or laser indentation on the intravascular stent delivery wire or pusher wire, for example.

"In another presently preferred aspect, a distance between the fixed marker band and the one or more floating marker bands is variable, and the distance between the fixed marker band and the one or more floating marker bands is self-adjusting in length by increasing or decreasing during advancement or retraction in response to anatomic vascular tortuosity to maintain smooth articulation.

"In another presently preferred aspect, a proximal segment of the self-expanding intravascular stent or medical device is mounted over the one or more floating marker bands. Alternatively, a distal segment of the self-expanding intravascular stent or medical device can be mounted over the one or more floating marker bands. Preferably the stent to intravascular stent delivery wire or pusher wire articulation in a tight vascular curvature is self-adjusting to provide a variable gap or length between the stent and the fixed marker band to facilitate ease of assembly advancement or retraction.

"In another presently preferred aspect, the apparatus for deploying and/or retrieving a self-expanding intravascular stent or medical device also includes a catheter or tubular sheath, and one or more struts or legs of the self-expanding intravascular stent or medical device extend beyond the one or more floating marker bands, so that the struts, legs or radiopaque markers of the self-expanding intravascular stent or medical device are constrained between the catheter or tube wall and at least one side of the one or more floating marker bands, which allows for the self-expanding intravascular stent or medical device to interface with intravascular stent delivery wire or pusher wire and for the self-expanding intravascular stent or medical device to maintain column strength and not to buckle under compression loads. In another presently preferred aspect, the self-expanding intravascular stent or medical device can be retrieved under tensile loads as the one or more floating marker bands will engage the struts, legs or radiopaque markers of the self-expanding intravascular stent or medical device.

"In another presently preferred aspect, the apparatus for deploying and retrieving a self-expanding intravascular medical device, includes an intravascular pusher wire having a distal portion and a proximal portion and at least one floating marker band movably constrained over the intravascular pusher wire. The at least one floating marker band is configured to releasably mount a self-expanding intravascular medical device thereon and at least one fixed marker band is fixedly attached to the intravascular pusher wire, with the at least one floating marker band movably retained to the at least one fixed marker band by at least one constraining member. A distance between the at least one fixed marker band and the at least one floating marker band may be self-adjusting. The apparatus may also include a self-expanding intravascular medical device having a proximal segment mounted to at least one floating marker band. The apparatus may also include a tubular sheath having a wall within which the self-expanding intravascular medical device is disposed, the self-expanding intravascular medical device having at least one strut extending over the at least one floating marker band and constrained by the wall of the tubular sheath and by at least one side of the at least one floating marker band. The at least one floating marker band may have an outside circumference of a polygonal shape selected from the group of polygonal shapes consisting of square and pentagonal shapes. The at least one constraining member may include at least one coil spring. The at least one constraining member may include at least one braid. The at least one constraining member may include at least one retainer wire. The at least one retainer wire may be connected to a ring on the at least one fixed marker band. The intravascular stent delivery wire may have an intermediate portion disposed between the distal portion and the proximal portion. The intravascular stent delivery wire may include a coiled wire portion and a core wire portion with the coiled wire portion being wrapped around the core wire portion. The core wire portion may extend uniformly from the proximal portion to the distal portion of the intravascular stent delivery wire. The coiled wire portion may vary between at least two of: the proximal portion, the intermediate portion, and the distal portion, in at least one of the following properties: distance between adjacent coils, diameter of coils, thickness of wire, and material composition of wire. The at least one floating marker band may separate at least one of the following: (i) the proximal portion and the intermediate portion of the intravascular stent delivery wire and (ii) the distal portion and the intermediate portion of the intravascular stent delivery wire. The at least one floating marker band may separate the proximal portion and the distal portion of the intravascular stent delivery wire. The apparatus of may also include at least one fixed marker band fixedly attached to the intravascular stent delivery wire, with the at least one floating marker band movably retained to the at least one fixed marker band. The at least one fixed marker band may separate at least one of the following: (i) the proximal portion and the intermediate portion of the intravascular stent delivery wire and (ii) the distal portion and the intermediate portion of the intravascular stent delivery wire. The at least one fixed marker band may separate the proximal portion and the distal portion of the intravascular stent delivery wire. The apparatus may include two or more of the fixed marker bands, and a self-expanding intravascular stent, with the stent deployable over at least two of the two or more fixed marker bands. The apparatus may include two or more of the floating marker bands, and a self-expanding intravascular stent, with the stent deployable over at least two of the two or more floating marker bands. The apparatus may also include a self-expanding intravascular stent, with the stent deployable over the at least one floating marker band and the at least one fixed marker band. The apparatus may include a floating marker band movably retained to the intravascular stent delivery wire by at least one constraining member. The constraining member may include a braid, a coil spring, or a retainer wire. The retainer wire may be connected to a ring or an indentation on the intravascular stent delivery wire. The intravascular stent delivery wire may have a tip that is free to rotate during advancement of the intravascular stent delivery wire into a vasculature, for ease of navigating tortuous vascular anatomy. The at least one retainer wire may be connected to a ring on the intravascular stent delivery wire. The at least one retainer wire may be connected to an indentation on the at least one fixed marker band. The at least one retainer wire may be connected to an indentation on the intravascular stent delivery wire.

"Other features and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments in conjunction with the accompanying drawings, which illustrate, by way of example, the operation of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

"FIG. 1 is a cross-sectional schematic diagram of the apparatus for deploying and/or retrieving a self-expanding intravascular stent or medical device according to the invention.

"FIG. 2 is a cross-sectional schematic diagram of a first variation of the apparatus for deploying and/or retrieving a self-expanding intravascular stent or medical device according to the invention.

"FIG. 3 is a cross-sectional schematic diagram of a second variation of the apparatus for deploying and/or retrieving a self-expanding intravascular stent or medical device according to the invention.

"FIG. 4 is a cross-sectional schematic diagram of a third variation of the apparatus for deploying and/or retrieving a self-expanding intravascular stent or medical device according to the invention.

"FIG. 5 is a cross-sectional schematic diagram of a fourth variation of the apparatus for deploying and/or retrieving a self-expanding intravascular stent or medical device according to the invention.

"FIG. 6 is a cross-sectional schematic diagram of the apparatus for deploying and/or retrieving a self-expanding intravascular stent or medical device according to the invention as in FIG. 1, with an additional floating marker band added to the other side of the fixed marker band.

"FIG. 7 is a cross-sectional schematic diagram of a first variation of the apparatus for deploying and/or retrieving a self-expanding intravascular stent or medical device according to the invention as in FIG. 2, with an additional fixed marker band added to the other side of the floating marker band.

"FIG. 8 is a plan view of a floating marker band having an outside circumference with a square shape.

"FIG. 9 is a plan view of a floating marker band having an outside circumference with a pentagonal shape.

"FIG. 10 is a cross-sectional schematic diagram of one embodiment of the intravascular delivery wire or pusher wire according to the present invention in which the wire includes an inner core wire portion and an outer coil wire portion.

"FIG. 11 is a plan view of one embodiment of the intravascular delivery wire or pusher wire according to the present invention in which the wire includes an inner core wire portion and an outer coil wire portion."

URL and more information on this patent application, see: Young, Eugene; Yeh, Chung Hao; Ken, Christopher G.M.; Ho, Thu Anh. Lock/Floating Marker Band on Pusher Wire for Self-Expanding Stents Or Medical Devices. Filed March 21, 2014 and posted August 28, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=1419&p=29&f=G&l=50&d=PG01&S1=20140821.PD.&OS=PD/20140821&RS=PD/20140821

Keywords for this news article include: Angiology, Depuy Synthes Products, Depuy Synthes Products Llc, Intravascular, Medical Devices, Self-Expanding Stent, Stenosis, Stent Delivery System, Surgery, Surgical Technology.

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Source: Politics & Government Week


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