US 20100070023 A1
An expandable bifurcated stent is formed of a main body and a first branch. The body wall is made up of interconnected stent members that define a plurality of cells, at least one of which is a side opening. The first branch body extends from the body wall from at least two regions adjacent the side opening. At least one stent member adjacent the perimeter is bioabsorbable.
1. A bifurcated stent comprising:
a plurality of interconnected stent members defining a side branch opening, the side branch opening having a perimeter and a plurality of deflectable members, the deflectable members having a first end and a second end, the first end engaged to the perimeter, the second end extending into the side branch opening, wherein at least two of the plurality of deflectable members are connected to one another via at least one bioabsorbable stent member.
2. The bifurcated stent of
3. The bifurcated stent of
4. The bifurcated stent of
5. The bifurcated stent of
6. The bifurcated stent of
7. The bifurcated stent of
8. The bifurcated stent of
9. A bifurcated stent comprising:
an unexpanded configuration and an expanded configuration;
a plurality of interconnected stent members defining a plurality of cells, at least one of the plurality of cells comprising a side opening, the side opening being shaped differently than the other cells, the side opening having a perimeter; and
a plurality of side branch petals extending from the perimeter into the side opening; in an unexpanded configuration, the side branch petals being connected one to another by at least one bioabsorbable stent member.
10. The bifurcated stent of
11. The bifurcated stent of
12. The bifurcated stent of
13. The bifurcated stent of
14. The bifurcated stent of
15. The bifurcated stent of
This application is a continuation of U.S. application Ser. No. 11/773,991, filed on Jul. 6, 2007.
Stents and similar devices such as stent, stent-grafts, expandable frameworks, and similar implantable medical devices, 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. 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.
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 U.S. 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.
Embodiments of the invention are directed to a bifurcated stent having an unexpanded state and an expanded state. The stent comprises a main body with a body wall. The body wall extends along a main longitudinal axis from a proximal end to a distal end and defines a lumen between the two ends. The body wall is comprised of interconnected stent members, a plurality of which defines a plurality of cells. At least one of the cells is a side opening having a perimeter. The side opening is shaped differently then the other cells of the stent.
The stent also comprises a first branch having a first branch body. The first branch body is positioned between the distal end and the proximal end of the main body and extends along a first branch longitudinal axis when the stent is in the expanded state. Furthermore, the first branch body extends from the body wall from at least a first region adjacent the side opening and a second region adjacent the side opening. At least one of the stent members adjacent the perimeter is bioabsorbable.
In some embodiments, the stent includes deflectable members which extend from the main body at positions about the perimeter of the side opening.
In at least one embodiment, the side opening perimeter includes a bioabsorbable expansion joint.
In at least one embodiment, the body wall comprises a plurality of circumferential rings, longitudinally offset from one another about the main longitudinal axis. The first branch body also comprises at least one branch ring being arranged about the first branch axis and extending from the perimeter of the side opening by at least one bioabsorbable stent member.
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 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 preferred 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.
In embodiments of the invention bioabsorbable members are constructed from one or more metals, polymers or combinations thereof that are corrodible so as to dissolve, dissociate or otherwise break down in the body without ill effect. Examples of such materials have been referred to as being degradable, biodegradable, biologically degradable, erodable, bioabsorbable, bioresorbable, and the like, and are herein collectively referred to as being bioabsorbable materials.
Examples of bioabsorbable materials include, but are not limited to, poly(hydroxyvalerate), poly(L-lactic acid), polycaprolactone, poly(lactide-co-glycolide), poly(hydroxybutyrate), poly(hydroxybutyrate-co-valerate), polydioxanone, polyorthoesters, polyanhydrides, poly(glycolic acid), poly(D,L-lactic acid), poly(glycolic acid-co-trimethylene carbonate), polyphosphoesters, polyphosphoester urethanes, poly(amino acids), cyanoacrylates, poly(trimethylene carbonate), poly(iminocarbonate), copoly(ether-esters) (e.g. PEO/PLA), polyalkylene oxalates, polyphosphazenes and biomolecules such as fibrin, fibrinogen, cellulose, starch, collagen, hyaluronic acid, etc., and mixtures thereof. Further examples of bioabsorbable materials may be found in U.S. Pat. Nos. 6,258,117, 6,409,754, and 7,022,132 and in U.S. Patent Application Publication No. 2002/0107560, the entire contents of which are incorporated herein by reference.
As stated above, the stent comprises a main body 15 and a first branch 20. The main body 15 comprises a body wall 25 made up of interconnected stent members 30. As seen in
Regarding the interconnected stent members 30, the stent members 30 include struts, connectors, sutures, expansion joints, combinations thereof, or any number of other structures suitable for use in constructing a stent. A plurality of the interconnected stent members 30 define a plurality of cells 55. At least one of the cells 55 is a side opening 60. The side opening 60 is distinguishable because it is shaped differently then the other cells of the stent. In some embodiments, the side opening 60 is larger than the other cells. Additionally, the side opening 60 has a perimeter 65. One of ordinary skill in the art will recognize that the perimeter 65 can be any number of shapes and is not limited to circular, elliptical, or any of the shapes specifically depicted in the drawings.
In addition to the main body, the stent further comprises a first branch 20 with a first branch body 75, as depicted in the embodiment shown in
The use of bioabsorbable stent members near or at the side opening is beneficial because it increases the stent's resistance to fatigue. When stents are juxtaposed or extended across a bifurcation in a vessel, for example, the juxtaposition or extension may stress areas of the stent. By placing bioabsorbable material at one or more of these high-stress areas, the bioabsorbable material will be gradually absorbed into the body, eliminating the stress. As a consequence of the absorption, the inventive stent will separate from itself, leaving in some embodiments the main body and the first branch body. Thus, the main vessel and the branch vessel will be kept open by the remaining portions of the stent. One skilled in the art will recognize that by selecting different bioabsorbable materials or varying the thickness of the bioabsorbable materials, the time it takes for the material to bioabsorb can be controlled. Thus in accordance with the present invention a bifurcated stent is provided wherein bioabsorbtion of a desired region or regions of the stent is made to occur immediately or soon after deployment, in several months, in several years, or at different rates for different regions of the stent. In some embodiments of the present invention, the first branch body comprises a plurality of deflectable members 95, as illustrated in side-view
Referring now to
In the embodiment depicted in
In some embodiments, as also depicted in
In the embodiment depicted in
In some embodiments, as depicted in
In at least one embodiment, as shown in
Referring now to
It should be noted that in the unexpanded state, the first branch body 75 would lie flat on the main body 15. The first branch body 75 could be expanded into a second lumen with a secondary balloon attached to the main balloon, a POBA balloon pushed through the center of the first branch body 75 and expanded, or a secondary deployment object such as a conic-shaped feature at the end of a catheter could be extended through first branch body 75 to push it open.
Referring now to the embodiment depicted in
In the embodiment depicted in
As mentioned above, the bifurcated stent of
The second branch 125 of stent 12 has a second branch body 130 which extends along a second branch longitudinal axis 135 when the stent 12 is in the expanded state. The second branch body 130 is also comprised of interconnected stent members 30.
As seen in
It should be noted that the terms “main body”, “first branch”, and “second branch” do not imply that the diameter of the main branch is larger than the diameters of the first or second branches. Although this could be true, it is not necessarily so. In some embodiments, the diameter of the first branch D2 or the diameter of the second branch D3 is equal to or greater than the main branch diameter D1.
Referring now to
As in other embodiments described above, the body wall 25 is comprised of interconnected stent members 30, a plurality of which define a plurality of cells 55. At least one of the cells 55 is a side opening 60. The side opening 60 is distinguishable because it is shaped differently then the other cells of the stent. In general, the side opening 60 is shaped differently than the other cells in that it is larger than the other cells. Additionally, the side opening 60 has a perimeter 65. In the embodiment depicted in
In some embodiments, the stent 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 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 preferred and alternate embodiments 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.