Patent Grant
8192477
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.
Stents may be delivered using suitable delivery systems. For example, a stent may be oriented about an inflation balloon of a delivery catheter. The catheter may be maneuvered through a bodily vessel to deliver the stent to a deployment site. The stent may be expanded by inflating the balloon with an inflation medium, such as a pressurized fluid. The balloon may then be deflated, and the catheter removed from the body.
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.
The present invention contemplates new and improved apparatuses that simplify placement of a stent at the site of a vessel bifurcation. Embodiments of the present invention include systems that provide improved trackability during delivery as well as accuracy of delivery.
It is understood that the term “shaft” includes the inner shaft, the outer shaft, or a combination of the inner shaft and outer shaft.
In at least one embodiment, the invention is directed to a catheter having an elongate catheter shaft with a distal region and a proximal region. The distal region of the catheter shaft defines a stent retaining region. Proximal to the stent retaining region, the catheter shaft defines at least one bend such that the bend is bent around the longitudinal axis of the vessel. The catheter also has a side branch guidewire housing which defines a side branch guidewire lumen; a side branch guidewire extends through the side branch guidewire lumen.
In some embodiments the catheter shaft proximal to the stent retaining region has plurality of bends such that the catheter shaft has a helical shape. That is, each bend, disposed about the longitudinal axis of the vessel, is joined to form a first helical path. In other embodiments, the path may be spiral rather than helical.
In at least one embodiment, the side branch guidewire is bent about the longitudinal axis of the vessel and is disposed about the catheter shaft.
In some embodiments, at least a portion of the catheter shaft is comprised of a braided material.
In other embodiments, the catheter shaft further defines an exchange port immediately proximally adjacent to a bend. The catheter shaft has a primary guidewire lumen and a primary guidewire which extends through the exchange port and the primary guidewire lumen. The exchange port is in communication with the primary guidewire lumen.
In at least one embodiment, the catheter also comprises an expandable balloon with a first length and a side branch guidewire housing with a second length wherein the second length is equal to or greater than the first length.
The trackability of a catheter through a vessel may be improved by improving the ability of the catheter to bend around the guidewires. By employing side branch guidewire housings of specific shapes, torque transfer may be improved over current methods.
In at least one embodiment, the cross-sectional width of the side branch guidewire housing is greater than the cross-sectional height.
In some embodiments, the side branch guidewire housing has a substantially elliptical cross-sectional shape.
In at least one embodiment, the cross-sectional shape of the side branch guidewire housing has a plurality of peaks and troughs wherein each peak is separated by a trough. The peaks are at a greater radial distance from the longitudinal axis of the catheter shaft than the troughs. In some embodiments, the troughs are substantially curvilinear.
The accuracy of the stent placement at a vessel bifurcation is critical. If the stent is not accurately placed, it is possible that the stent will be deployed too close to either the carina or contralateral wall of the vessel side branch, thereby causing a stenosis to form. The stenosis may grow into the stent and result in stent occlusion.
In some embodiments, at least a portion of the side branch guidewire housing extends at an oblique angle away from the expandable balloon. Disposed about the oblique-angled portion of the side branch guidewire housing is an expandable centering band which, in some embodiments, defines a centering band inflation lumen. The expandable centering band has an expanded state and an unexpanded state and, in embodiments with a centering band inflation lumen, is in fluid communication with the centering band inflation lumen. Adapted to receive an inflation fluid, the centering band is substantially filled with inflation fluid in the expanded state, and is substantially free of inflation fluid and substantially ring-shaped in the unexpanded state.
In at least one embodiment, the centering band is substantially conical in the expanded state. Specifically, the centering band has a vertex and a base wherein the vertex has a diameter less than that of the base, and the vertex is closer to the expandable balloon than the base. In other embodiments, the base is closer to the expandable balloon than the vertex.
The trackability of a catheter system may be improved by altering the flexibility characteristics of the catheter shaft. By making the catheter shaft more flexible in some regions than in other regions, the catheter system may be advanced through the vasculature with less difficulty, thereby potentially reducing damage to the vessel walls as well as increasing delivery accuracy. Furthermore, altering the shape of the catheter shaft may produce similar desirable effects.
In at least one embodiment, a portion of the catheter shaft comprises a flexible, pleated region. In some embodiments the flexible, pleated region extends around the entire circumference of a portion of the catheter shaft. In other embodiments the flexible, pleated region is disposed about only a section of the circumference of the portion of the catheter shaft.
In at least one embodiment, the catheter shaft has a cross-section and comprises a body with an interior, exterior, and a longitudinal axis. The exterior has a plurality of peaks and troughs, each peak being separated by a trough. The peaks are at a greater radial distance from the longitudinal axis of the catheter shaft than the troughs. In some embodiments, the interior defines a substantially circular region. In other embodiments, the troughs are substantially curvilinear.
In at least one embodiment, the interior, like the exterior, comprises a plurality of peaks and troughs, each peak being separated by a trough. The peaks are at a greater radial distance from the longitudinal axis of the catheter shaft than the troughs. The peaks of the interior radially correspond to the peaks of the exterior and the troughs of the interior radially correspond to the troughs of the exterior. In some embodiments, at least a portion of at least one peak comprises a support. The support, substantially parallel to the longitudinal axis of the body, extends through the peak.
In at least one embodiment, the body is comprised of a first material and the support is comprised of a second material, the first material being different from the second material. In some embodiments the first material is more flexible than the second material. In other embodiments the first material is less flexible than the second material.
In some embodiments the cross-section of the catheter shaft is substantially triangular.
The trackability of a catheter system may also be improved by altering the push characteristics of the catheter shaft. Being able to change the longitudinal stiffness, that is, the push characteristics, of the catheter shaft, the catheter system may be advanced through the vasculature with less difficulty, thereby potentially reducing damage to the vessel walls as well as increasing delivery accuracy.
For example, in at least one embodiment the invention is directed to a catheter having an elongate catheter shaft with a distal region and a proximal region. The catheter shaft comprises a substantially tubular wall and defines an inflation lumen. The distal region of the catheter shaft defines a stent retaining region. Proximal to the stent retaining region, the catheter shaft defines at least one bend such that the bend is bent around the longitudinal axis of the vessel. The catheter also has a side branch guidewire housing which defines a side branch guidewire lumen; a side branch guidewire extends through the side branch guidewire lumen. Furthermore, the catheter system comprises at least one support member having a first portion and a second portion such that the first portion is more flexible than the second portion.
In some embodiments the first portion comprises at least one flexible, pleated region. In other embodiments, the support member is wire. In at least one embodiment, the support member is a polymer. In at least one embodiment the support member extends through at least a portion of the inflation lumen. In some embodiments, the support member extends through at least a portion of the tubular wall.
Push characteristics may be altered by using varied inflation methods and/or mechanisms within the catheter shaft. For example, in at least one embodiment of the invention the catheter shaft comprises a substantially tubular wall having an inner diameter defining a first inflation lumen for balloon inflation. A second inflation lumen, capable of altering the push characteristics, extends longitudinally through at least a portion of the tubular wall. The second inflation lumen is capable of being inflated independent of the first inflation lumen.
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 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.
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.
Aligning a stent with the side branch of a vessel bifurcation is a difficult task and is achieved by allowing the catheter system to rotate into place via guidewires. A side branch guidewire 45 and a primary guidewire 166 are spaced sufficiently apart, as is known in art, in order to define a path by which a catheter system 5 can track. As catheter system 5 tracks along the two guidewires (45 and 166), it will twist and/or rotate as a result of the torque created by the guidewire location. Side branch guidewire 45 is bent about longitudinal axis 35 and is disposed about the catheter shaft 15. This configuration allows at least side branch guidewire 45 and primary guidewire 166 to cross the catheter shaft 15 multiple times without becoming entangled, a common problem that results when twisting a guidewire to align a catheter system.
Because catheter shaft 15 needs to be able to twist under low loads, it may be constructed of a flexible material. Although a soft durometer material is preferable, a braided material 65, as shown in
A technique of improving flexibility, which may improve trackability, is to provide a catheter system with a long side branch guidewire housing. Relative to a short side branch guidewire housing, a long side branch guidewire housing will have more flexibility at the distal end of the guidewire housing.
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.
Another aspect of the invention is shown in
In some embodiments of the invention, an expandable centering band 125 is provided, as depicted in
The trackability of a catheter system may be improved by altering the flexibility characteristics of the catheter shaft. By making the catheter shaft more flexible in some regions than in other regions, the catheter system may be advanced through the vasculature with less difficulty, thereby potentially reducing damage to the vessel walls as well as increasing delivery accuracy. To that end, another embodiment of the invention is presented in
In addition to using flexible, pleated regions, altering the shape of the catheter shaft may produce similarly desirable trackability effects by aiding the catheter system's ability to twist.
Another embodiment of the invention is shown in
Trackability and/or push may be improved with the introduction of a support member extending through a catheter shaft. In the embodiment depicted in
Still referring to
Push may be further improved with the addition of a push inflation lumen, as shown in
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.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4576142 | Schiff | Mar 1986 | A |
| 5037392 | Hillstead | Aug 1991 | A |
| 5078727 | Hannam et al. | Jan 1992 | A |
| 5146925 | Snow | Sep 1992 | A |
| 5163928 | Hobbs et al. | Nov 1992 | A |
| 5290230 | Ainsworth et al. | Mar 1994 | A |
| 5338295 | Cornelius et al. | Aug 1994 | A |
| 5409458 | Khairkhahan et al. | Apr 1995 | A |
| 5489271 | Andersen | Feb 1996 | A |
| 5545132 | Fagan et al. | Aug 1996 | A |
| 5743875 | Sirhan et al. | Apr 1998 | A |
| 5749825 | Fischell et al. | May 1998 | A |
| 5873865 | Horzewski et al. | Feb 1999 | A |
| 6059823 | Holman et al. | May 2000 | A |
| 6096073 | Webster et al. | Aug 2000 | A |
| 6099497 | Adams et al. | Aug 2000 | A |
| 6117117 | Mauch | Sep 2000 | A |
| 6174327 | Mertens et al. | Jan 2001 | B1 |
| 6544218 | Choi | Apr 2003 | B1 |
| 6596020 | Vardi et al. | Jul 2003 | B2 |
| 6607534 | Bonutti | Aug 2003 | B2 |
| 6679860 | Stiger | Jan 2004 | B2 |
| 6706062 | Vardi et al. | Mar 2004 | B2 |
| 6709429 | Schaefer et al. | Mar 2004 | B1 |
| 6749628 | Cho et al. | Jun 2004 | B1 |
| 20010003161 | Vardi et al. | Jun 2001 | A1 |
| 20010007082 | Dusbabek et al. | Jul 2001 | A1 |
| 20030055483 | Gumm | Mar 2003 | A1 |
| 20030181923 | Vardi | Sep 2003 | A1 |
| 20040039326 | Hata et al. | Feb 2004 | A1 |
| 20040073286 | Armstrong et al. | Apr 2004 | A1 |
| 20040097965 | Gardeski et al. | May 2004 | A1 |
| 20040102719 | Keith et al. | May 2004 | A1 |
| 20040172119 | Eidenschink | Sep 2004 | A1 |
| 20040220606 | Goshgarian | Nov 2004 | A1 |
| 20050015108 | Williams et al. | Jan 2005 | A1 |
| 20060058864 | Schaeffer et al. | Mar 2006 | A1 |
| Number | Date | Country |
|---|---|---|
| 0 897 700 | Feb 1999 | EP |
| 2 771 013 | May 1999 | FR |
| 3531 | Jan 1913 | GB |
| WO 9313827 | Jul 1993 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 20070112407 A1 | May 2007 | US |
