Patent Application
20070050016
Not Applicable
Not Applicable
1. Field of the Invention
In some embodiments this invention relates to implantable medical devices, their manufacture, and methods of use. Some embodiments are directed to delivery systems, such as catheter systems of all types, which are utilized in the delivery of such devices.
2. Description of the Related Art
A stent is a medical device introduced to a body lumen and is well known in the art. Typically, a stent is implanted in a blood vessel at the site of a stenosis or aneurysm endoluminally, i.e. by so-called “minimally invasive techniques” in which the stent in a radially reduced configuration, optionally restrained in a radially compressed configuration by a sheath and/or catheter, is delivered by a stent delivery system or “introducer” to the site where it is required. The introducer may enter the body from an access location outside the body, such as through the patient's skin, or by a “cut down” technique in which the entry blood vessel is exposed by minor surgical means.
Stents, grafts, stent-grafts, vena cava filters, expandable frameworks, and similar implantable medical devices, collectively referred to hereinafter as stents, are radially expandable endoprostheses which are typically intravascular implants capable of being implanted transluminally and enlarged radially after being introduced percutaneously. Stents may be implanted in a variety of body lumens or vessels such as within the vascular system, urinary tracts, bile ducts, fallopian tubes, coronary vessels, secondary vessels, etc. Stents may be used to reinforce body vessels and to prevent restenosis following angioplasty in the vascular system. They may be self-expanding, expanded by an internal radial force, such as when mounted on a balloon, or a combination of self-expanding and balloon expandable (hybrid expandable).
Stents may be created by methods including cutting or etching a design from a tubular stock, from a flat sheet which is cut or etched and which is subsequently rolled or from one or more interwoven wires or braids.
Within the vasculature, it is not uncommon for stenoses to form at a vessel bifurcation. A bifurcation is an area of the vasculature or other portion of the body where a first (or parent) vessel is bifurcated into two or more branch vessels. Where a stenotic lesion or lesions form at such a bifurcation, the lesion(s) can affect only one of the vessels (i.e., either of the branch vessels or the parent vessel) two of the vessels, or all three vessels. Many prior art stents however are not wholly satisfactory for use where the site of desired application of the stent is juxtaposed or extends across a bifurcation in an artery or vein such, for example, as the bifurcation in the mammalian aortic artery into the common iliac arteries.
The art referred to and/or described above is not intended to constitute an admission that any patent, publication or other information referred to herein is “prior art” with respect to this invention. In addition, this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 C.F.R. §1.56(a) exists.
All US patents and applications and all other published documents mentioned anywhere in this application are incorporated herein by reference in their entirety.
Without limiting the scope of the invention a brief summary of some of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Detailed Description of the Invention below.
A brief abstract of the technical disclosure in the specification is provided as well only for the purposes of complying with 37 C.F.R. 1.72. The abstract is not intended to be used for interpreting the scope of the claims.
This invention contemplates a number of embodiments where any one, any combination of some, or all of the embodiments can be incorporated into a stent and/or a stent delivery system and/or a method of use.
At least one embodiment of the invention is directed to a stent having a generally tubular first stent body positioned within a circumferential plane defining a first lumen having deployed and undeployed states, expanded and unexpanded states, and an expanding side branch assembly also having a deployed and undeployed state where the side branch assembly in the unexpanded state is completely or substantially along or within the first stent body and in the expanded state the side branch assembly defines a second lumen partially within the first lumen and partially without.
At least one embodiment of the invention is directed to a stent having a second fluid lumen which is restrained from expansion by a member of the first stent body in the unexpanded state and in the expanded state is not restrained from expansion by the member of the first stent body.
In at least one possible embodiment the side branch assembly is self-expanding.
In at least one possible embodiment the side branch assembly is balloon expandable.
In at least one possible embodiment, the undeployed side branch is positioned entirely within the lumen of the first stent body.
In at least one embodiment, the self expansion mechanism includes biased members of the side branch assembly which in the unexpanded state are restrained by blocking struts of the main stent body and in the expanded state are released when restraining struts of the main stent body are withdrawn.
In at least one embodiment, the second stent body is comprised of a plurality of side branch projections and a mounting ring, each of the side branch projections having a free end and an engaged end with the engaged end is engaged to the mounting ring.
In at least one embodiment, the stent includes a mounting ring engaged to the first stent body by at least one engagement region adjacent to the first side branch opening.
In at least one embodiment, the second fluid lumen is a second stent body.
In at least one embodiment, the second stent body also comprises a plurality of engagement members, the engagement members extending from a mounting ring to at least one engagement region of the first stent body.
In at least one embodiment, the first stent body is comprised of a plurality of interconnected first stent members, adjacent first stent members defining a plurality of openings through the first stent body in fluid communication with the lumen, at least one of the openings being the first side branch opening.
In at least one embodiment the stent has a plurality of side branch openings each with an area.
In at least one embodiment the stent has a plurality of side branch openings each with an area and the area of at least one side branch opening is greater than or smaller than that of each of the remaining openings.
In at least one embodiment the stent has a plurality of side branch openings and the first side branch opening and the second side branch opening are coaxially positioned relative to one another.
In at least one embodiment, the side branch assembly is a second stent body which in the undeployed state comprises a substantially tubular shape and has a common longitudinal axis with first stent body.
In at least one embodiment, the first stent body has an end-to-end length and the second stent body has an end-to-end length, and the end-to-end length of the second body is shorter than the end-to-end length of the first stent body.
In at least one embodiment, when in the undeployed state, no first stent body members are positioned across the second side branch opening.
In at least one embodiment, the self expansion mechanism is a constrained by a sheath surrounding the stent until after expansion, which when withdrawn, allows the side branch assembly to self expand.
In at least one embodiment, the self expansion mechanism is a plurality of biased wires, restrained by the stent geometry in the unexpanded state but which are released when the stent expands either pulls or pushes the side branch assembly away from the main stent body.
In at least one embodiment, the self expansion mechanism is a plurality of hooks, connecting the side branch to the main stent body which are pushed by the stent expansion into rotating which pushes the side branch away from the main stent body.
These and other embodiments which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for further understanding of the invention, its advantages and objectives obtained by its use, reference should be made to the drawings which form a further part hereof and the accompanying descriptive matter, in which there is illustrated and described a embodiments of the invention.
A detailed description of the invention is hereafter described with specific reference being made to the drawings.
While this invention may be embodied in many different forms, there are described in detail herein specific embodiments of the invention. This description is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated.
For the purposes of this disclosure, like reference numerals in the figures shall refer to like features unless otherwise indicated.
Depicted in the figures are various aspects of the invention. Elements depicted in one figure may be combined with, and/or substituted for, elements depicted in another figure as desired.
Referring now to
In at least one embodiment, the second fluid lumen is a second stent body which in the undeployed state can also comprise a substantially tubular shape, the lumen and the longitudinal axis of the first stent body being common to the second stent body.
This illustration features one possible embodiment where the side branch opening 12 is covered. In
The effects of expanding the stent 9 is illustrated in
The expansion of either or both of the main stent body 1 or the side branch assembly 15 could have been accomplished by balloon expansion or self expansion. The side branch assembly can be constructed out of any one or any combination of materials including but not limited to polymers, stainless steel, nickel, titanium, niobium etc. The side branch projection extends along a second longitudinal axis 11 forming an oblique angle 2 to the first longitudinal axis. For the purposes of this application, the term “oblique” refers to an angle of between 1 and 180 degrees and explicitly includes angles of about 90 degrees.
Referring now to
In at least one embodiment, an example of which is shown in
The mounting ring 22 can be connected to the main stent body 1 at an engagement region adjacent to the side branch opening 12. In another embodiment, the mounting ring 22 can also have a plurality of engagement members extending from the mounting ring 22 to at least one engagement region of the first stent body 1.
The stent 9 can be constructed to have two or more side branch assembles 15 and side branch openings 12. In addition, the multiple side branch openings can have differing areas and the different side branch projections can have differing lengths. The multiple side branches can be coaxially located or positioned anywhere along the surface of the first stent body 1.
The side branch assembly 15 can be constructed in such a manner as to be self expanding. In the unexpanded state, this biased side branch assembly 15 is restrained, but once the restraint is removed, the side branch assembly 15 self expands and forms a second fluid lumen 16.
In at least one embodiment, a sheath encapsulates the stent 9 in the unexpanded state and can act to restrain a biased self expanding side branch 15. In this possible embodiment, once the sheath is removed, the now unrestrained side branch assembly 15 can self expand. This mechanism allows for the side branch to expand before, after, or at substantially the same time that the main stent body 1 expands.
In at least one embodiment, in the unexpanded state, at least one strut member 5 of the main stent body 1 is positioned in such a manner as to block self expansion of the side branch assembly 15. As the stent expands, the strut member 5 is pushed away from the side branch assembly 15, which allows it to self-expand.
Referring now to
In embodiments wherein the side branch assembly 15 is configured to be self expanding, this movement will release the projecting member 16 to self-expand. In the case of a balloon expandable side branch assembly 15, movement of the strut(s) 5 away would allow balloon expansion to extend the side branch assembly 15. As mentioned before, this inventive concept is not limited to stents comprising struts and side branches comprising projecting members and can be accomplished with any stent structure in which in the unexpanded state the stent has a structural component adjacent to the structural components of the side branch assembly and in the expanded state the structural components are moved away from the side branch assembly.
Referring now to
Now referring to
The mounting ring 22 of the side branch assembly can also be connected to the first stent body 1 by a plurality of engagement members. Embodiments of this are illustrated in
In
This wire-stent connector can also function as an additional or alternative mechanism for expanding the side branch projection by pushing the side branch projection away from the circumferential plane of the stent. As the main stent body expands, the expansion moves the wire-stent connector 50 which can either push or pull the wire 36 to move the side branch assembly 15 into an expanded state.
In
The inventive stents may be made from any suitable biocompatible materials including one or more polymers, one or more metals or combinations of polymer(s) and metal(s). Examples of suitable materials include biodegradable materials that are also biocompatible. By biodegradable is meant that a material will undergo breakdown or decomposition into harmless compounds as part of a normal biological process. Suitable biodegradable materials include polylactic acid, polyglycolic acid (PGA), collagen or other connective proteins or natural materials, polycaprolactone, hylauric acid, adhesive proteins, co-polymers of these materials as well as composites and combinations thereof and combinations of other biodegradable polymers. Other polymers that may be used include polyester and polycarbonate copolymers. Examples of suitable metals include, but are not limited to, stainless steel, titanium, tantalum, platinum, tungsten, gold and alloys of any of the above-mentioned metals. Examples of suitable alloys include platinum-iridium alloys, niobium alloys, cobalt-chromium alloys including Elgiloy and Phynox, MP35N alloy and nickel-titanium alloys, for example, Nitinol.
The inventive stents may be made of shape memory materials such as superelastic Nitinol or spring steel, or may be made of materials which are plastically deformable. In the case of shape memory materials, the stent may be provided with a memorized shape and then deformed to a reduced diameter shape. The stent may restore itself to its memorized shape upon or after being heated to a transition temperature and having any restraints removed therefrom.
The inventive stents may be created by methods including cutting or etching a design from a tubular stock, from a flat sheet which is cut or etched and which is subsequently rolled or from one or more interwoven wires or braids. Any other suitable technique which is known in the art or which is subsequently developed may also be used to manufacture the inventive stents disclosed herein.
In some embodiments the stent, the delivery system or other portion of the assembly may include one or more areas, bands, coatings, members, etc. that is (are) detectable by imaging modalities such as X-Ray, MRI, ultrasound, etc. In some embodiments at least a portion of the stent and/or adjacent assembly is at least partially radiopaque.
In some embodiments the at least a portion of the stent is configured to include one or more mechanisms for the delivery of a therapeutic agent. Often the agent will be in the form of a coating or other layer (or layers) of material placed on a surface region of the stent, which is adapted to be released at the site of the stent's implantation or areas adjacent thereto.
A therapeutic agent may be a drug or other pharmaceutical product such as non-genetic agents, genetic agents, cellular material, etc. Some examples of suitable non-genetic therapeutic agents include but are not limited to: anti-thrombogenic agents such as heparin, heparin derivatives, vascular cell growth promoters, growth factor inhibitors, Paclitaxel, etc. Where an agent includes a genetic therapeutic agent, such a genetic agent may include but is not limited to: DNA, RNA and their respective derivatives and/or components; hedgehog proteins, etc. Where a therapeutic agent includes cellular material, the cellular material may include but is not limited to: cells of human origin and/or non-human origin as well as their respective components and/or derivatives thereof. Where the therapeutic agent includes a polymer agent, the polymer agent may be a polystyrene-polyisobutylene-polystyrene triblock copolymer (SIBS), polyethylene oxide, silicone rubber and/or any other suitable substrate.
The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. The various elements shown in the individual figures and described above may be combined or modified for combination as desired. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”.
Further, the particular features presented in the dependent claims can be combined with each other in other manners within the scope of the invention such that the invention should be recognized as also specifically directed to other embodiments having any other possible combination of the features of the dependent claims. For instance, for purposes of claim publication, any dependent claim which follows should be taken as alternatively written in a multiple dependent form from all prior claims which possess all antecedents referenced in such dependent claim if such multiple dependent format is an accepted format within the jurisdiction (e.g. each claim depending directly from claim 1 should be alternatively taken as depending from all previous claims). In jurisdictions where multiple dependent claim formats are restricted, the following dependent claims should each be also taken as alternatively written in each singly dependent claim format which creates a dependency from a prior antecedent-possessing claim other than the specific claim listed in such dependent claim below.
This completes the description of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.
