Patent Application
20080177301
The present invention relates to an apparatus and method for anchoring a prosthetic structure to a body tissue and, more particularly, to anchoring a prosthetic structure to a body tissue using a suture member and at least one terminal feature.
In recent years, methods and devices have been developed for inserting a prosthetic structure, discussed herein as being a graft, in a percutaneous or endovascular manner at a desired location within a patient's body. These techniques typically involve a catheter-carried tubular graft delivered through the vascular system to the desired location. The graft may include a tubular graft body supported by an expandable stent, either self-expanding or balloon-expanding. The balloon-expanding type of stent naturally requires an expansion balloon, while the self-expanding type is simply deployed from the end of a tubular sheath.
When the graft installation procedure does not involve cardiopulmonary bypass, blood continues to flow through the vascular system. Certain complications may arise in anchoring the graft to the inner wall of the vessel, because of the blood flow through the vessel both during the procedure and afterward. Indeed, the risk of grafts migrating within a body lumen is a problem in many locations, not just in a blood vessel. Surgeons often require various minimum lengths of healthy body lumen wall adjacent the target location for anchoring the graft and allowing for the graft to shift before an endovascular graft repair is indicated, or else a conventional invasive technique must be used. The latter may cause increased discomfort for the patient or even remove the graft procedure as an option for the patient's treatment. Therefore, it is desirable to anchor the graft endovascularly and with a minimum of healthy body lumen wall adjacent the desired implantation site.
A number of techniques have been proposed for anchoring grafts in a desired location, such as by suturing, stapling, or wiring the graft to the adjacent body tissue. However, puncturing through the body tissue with the suture member, staple, or wire may damage the body tissue and cause complications. Alternatively, some grafts have portions extending beyond the graft body which may be bent outward into contact with the body tissue, either through pre-shaping using a memory alloy or from expansion of a balloon against the extension portion. These extension portions may be complicated and expensive to provide, and may be difficult to custom-fit to a particular application of the graft if adjacent body tissue structures are different than those anticipated by the graft manufacturer.
Alternatively, grafts may be allowed to become naturally fixed to the vessels by tissue ingrowth. For example, some manufacturers have provided grafts having texturized surfaces to provide increased surface area for the body tissue to grow into. One such texturized graft is knitted, and includes a plurality of loops extending from the exterior surface of the graft. One known drawback associated with this configuration is that the knitted graft, which is composed of loosely looped fabrics or threads, is very easily expandable. Such a graft may be subject to undesirable stretching and/or deformation within the body. Another type of texturized graft, an example of which is disclosed in U.S. Pat. No. 6,663,667, is equipped with a plurality of loosely associated threads or fibers, which may be affixed to, woven into, or sewn to the exterior surface of the graft.
Neither of these texturized grafts, however, sufficiently encourages tissue ingrowth into the graft in a suitably timely manner to resist initial migration of the graft. Such ingrowth is a natural bodily process that may be used to anchor the graft, and prevent undesirable migration. Nevertheless, the ingrowth happens gradually over time and will not assist in maintaining the graft in the desired position at or shortly after the time of installation.
Accordingly, it is desirable to provide an apparatus and method for use of an anchor which maintains a prosthetic structure in a desired relationship with a body tissue starting at the time of installation and promoting tissue ingrowth into the prosthetic structure to assist in long-term anchoring of the prosthetic structure to the body tissue.
In an embodiment of the present invention, a method of anchoring a prosthetic structure to a body tissue is described. A suture member having first and second ends longitudinally separated by a suture midsection is provided. The suture member is fastened to the prosthetic structure with at least one of the first and second ends being located adjacent a tissue-contacting surface of the prosthetic structure. At least one terminal feature is formed on at least one of the first and second ends located adjacent the tissue-contacting surface of the prosthetic structure. The body tissue is engaged with at least one terminal feature to anchor the prosthetic structure to the body tissue.
In an embodiment of the present invention, an apparatus for anchoring a prosthetic structure to a body tissue is described. The apparatus includes a suture member having first and second ends longitudinally separated by a suture midsection. The suture member is connected to the prosthetic structure. At least one of the first and second ends is located adjacent a tissue-contacting surface of the prosthetic structure. At least one terminal feature is associated with at least one of the first and second ends and is adapted to engage the body tissue for anchoring the prosthetic structure to the body tissue.
For a better understanding of the invention, reference may be made to the accompanying drawings, in which:
In accordance with the present invention,
The terminal feature 116 may be a separate anchor member attached to at least one of the first and second ends 110 and 112, or may be an integral anchor member formed from at least one of the first and second ends. The term “anchor member” is used to denote any structure which can be used to help maintain the graft 100 in a desired relationship with a body tissue. For example, a hook or barb (not shown) could be formed from, or attached to, at least one of the first and second ends 110 and 112 to serve as an anchor member. The terminal feature 116 may be at least partially insertible into the body tissue for a mechanical engagement therewith. Alternately, the terminal feature 116 could include an adhesive, suction cup, or other noninvasive structure (not shown) to mechanically engage with a surface of the body tissue without being inserted therein.
Whether or not the terminal feature 116 is insertible into the body tissue, the terminal feature may biologically engage with the body tissue. A “biological engagement” is an engagement in which the body tissue exhibits tissue ingrowth over time with at least a portion of the apparatus 106. For example, the body tissue could grow over and subsume at least a portion of the terminal feature 116 and thereby anchor the graft 100.
As shown in the Figures, the anchor member serving as a terminal feature 116 could have a disc shape, with the disc shape being adapted to engage the body tissue.
As is apparent from the cross-sectional view of
At least one of the first and second ends 110 and 112 may be located adjacent the tissue-contacting surface 420. Moreover, the first and second ends 110 and 112 may be fastened together adjacent the tissue-contacting surface 420. For example, the first and second ends 110 and 112 may be tied together in at least one knot, such as an overhand knot. Alternatively, the first and second ends 110 and 112 may be adhered or fused together or fastened by a separately provided fastener (not shown).
Second, the needle 526 is passed through at least a portion of the prosthetic thickness 424 to fasten the suture member 108 to the graft 100. For example, and as shown in
Next, the first and second ends 110 and 112 may be fastened together.
After the first and second ends 110 and 112 are fastened together, the first end 110 may be disconnected from the needle. As shown schematically in
Next, at least one terminal feature 116 is formed on or attached to at least one of the first and second ends 110 and 112 located adjacent the tissue-contacting surface 420 of the graft 100. In
The above or a similar sequence of steps may be performed as many times as desired to provide a graft 100 with at least one apparatus 106. The apparatuses 106 may be provided to the graft 100 in advance or may be created by the user just before the graft 100 is implanted into the patient. Once the desired number and arrangement of apparatuses 106 have been provided, the graft 100 is placed in the desired location within the patient's body.
As the graft 100 is arranged by the user at the implantation site, at least one terminal feature 116 engages the body tissue adjacent the graft within the patient's body. The terminal feature 116 serves to anchor the graft 100 to the body tissue in a desired manner, initially through a mechanical engagement and, as time progresses, through biological engagement caused by tissue ingrowth. Optionally, some portion of the graft 100 and/or apparatus 106 may include a therapeutic agent or be made from a therapeutic material to encourage such biological engagement.
While aspects of the present invention have been particularly shown and described with reference to the preferred embodiment above, it will be understood by those of ordinary skill in the art that various additional embodiments may be contemplated without departing from the spirit and scope of the present invention. For example, the prosthetic structure 100 could be shaped as a tube, a two-sided sheet, a closed geometric shape, an open frame, or have any other suitable prosthetic structure shape. The body tissue could be any tissue inside or outside the body, including but not limited to an inner or outer surface of blood vessels, skin, muscle, bone, glands, other organs, and the like. The apparatus 106 could be attached to one or more of a stent 102, a graft body 104, an apparatus support (not shown) attached to the prosthetic structure 100, or any other suitable structure. The terminal feature 116 may be produced without heat, depending upon the material of the suture member 108. As with all structures discussed above, the suture member 108 may be made of any suitable material and have any suitable dimensions. One of the first and second ends 110 and 112 could be fastened to the graft 100, with the suture midsection 114 and the other of the first and second ends extending away from the tissue-contacting surface 420. The manufacturing steps depicted in
The method and apparatus of certain embodiments of the present invention, when compared with other apparatus and methods, may have the advantages of maintaining a prosthetic structure in a desired relationship with a body tissue starting at the time of installation and promoting tissue ingrowth into the prosthetic structure to assist in long-term anchoring of the prosthetic structure to the body tissue. Such advantages are particularly worthy of incorporating into the design, manufacture, and operation of prosthetic structures. In addition, the present invention may provide other advantages which have not yet been discovered.
Other aspects, objects, and advantages of the present invention can be obtained from a study of the drawings, the disclosure, and the appended claims.
This application claims priority from U.S. Provisional Application No. 60/848,820, filed Oct. 2, 2006, the subject matter of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60848820 | Oct 2006 | US |
