Expandable suture anchor
An expandable suture anchor is provided for use with an applicator. The suture anchor has a body formed from a biocompatible spring material such that the suture anchor has a first configuration when positioned within the applicator and a second configuration after deployment from the applicator, wherein the second configuration has a geometric shape that is broader in at least one plane than the first configuration.
The present application relates to surgical fasteners and instruments for approximating and fastening tissue and, more particularly, to suture anchors and associated instruments for endoscopically attaching sutures to tissue.
The working channel of a flexible endoscope typically has a diameter in the range of about 2.5 to about 4 millimeters. Current staplers and suturing devices cannot be easily redesigned to work through such small openings. In addition, performing procedures by way of the working channel does not easily permit using two instruments positioned at different angles with respect to the wound site in order to “pass and catch” a needle and apply sutures.
Various clips, suture fasteners and anchors have been developed such that physicians (e.g., gastroenterologists) may endoscopically close perforations in the gastrointestinal tract resulting from, for example, ulcers or polypectomy. One type of suture anchor is known as a “T-tag ”fastener. The T-tag is a small metallic pin with a suture attached at the middle. The physician may load the T-tag into the end of a cannulated needle of an applicator that may be inserted through the working channel of a flexible endoscope. The physician may push the needle into the tissue near the perforation and implant the T-tag into the tissue with the attached suture trailing through the working channel and out the proximal end of the endoscope. After two or more T-tags are attached to the tissue near the wound in this manner, the physician may pull the sutures to appose the tissue around the wound. The physician may then fasten the sutures together by applying a plurality of alternating, right and left overhand knots using a knot pushing device or by applying a knotting element or other type of fastener through the working channel of the endoscope.
In order for T-tags to resist pull-out from the tissue when the attached suture is tensioned, the T-tag should rotate after ejection from the cannulated needle to be approximately perpendicular to the attached suture. An issue typically associated with anchors such as the T-tag is that if the anchor is implanted within tissue layers, rather than through tissue layers such that the anchor cannot reorient as described, it is possible for the T-tag to be easily pulled from the hole created by the penetrating needle.
Another issue typically associated with current suture anchors such as the T-tag is the occasional situation in which the anchor comes out of the distal end of the cannulated needle while the applicator is manipulated into the endoscope and towards the wound site.
An issue typically associated with current suture anchor applicators is the risk that nearby organs may be accidentally injured by the needle of the applicator. The physician normally cannot see anatomical structures on the distal side of the tissue layers when the needle is being pushed through the tissue layers. Therefore, there is a risk that adjacent organs may be accidentally injured by the penetrating needle.
In addition to addressing the above issues, it may be desirable to provide an improved suture anchor that is magnetic resonance imaging (MRI) compatible. For example, the anchor may be formed from a non-ferrous material.
Accordingly, there is a need for an improved suture anchor that may be securely retained in a suture anchor applicator until deployment into the tissue near a wound. In addition, there is a need for a suture anchor with improved resistance to pull-out from tissue, whether implanted within tissue layers or through tissue layers. Furthermore, there is a need for an improved suture anchor and suture anchor applicator that helps to prevent accidental injury to nearby anatomical structures during deployment of the anchor into tissue near a wound site. Finally, there is a need for an improved suture anchor that may be formed from a non-ferrous material in order to be MRI compatible.
SUMMARYIn one embodiment, an expandable suture anchor is provided for use with an applicator. The suture anchor includes a body formed from a biocompatible spring material such that the suture anchor has a first configuration when positioned within the applicator and a second configuration when deployed from the applicator, wherein the second configuration has a geometric shape that is broader in at least one plane than the first configuration.
In another embodiment, an expandable suture anchor for use with an applicator includes a body formed from a nickel-titanium memory material such that the suture anchor has a first configuration when positioned within the applicator and a second configuration after deployment from the applicator. The second configuration has a geometric shape that is broader in at least one plane than the first configuration. The body has an approximately cylindrical shape defining a longitudinal axis when in the first configuration and includes at least one leg that is springably deformable such that a portion of the leg extends further in an outwardly direction from the axis in the second configuration than in the first configuration. The suture anchor also includes a surgical suture threaded through an aperture of the body and retainably attached to the body by a knot in the suture or a ferrule crimped onto the suture to the body, wherein the suture extends from approximately the middle of the body when in the second configuration.
In another embodiment, an expandable suture anchor for use with an applicator includes a body formed from a planar sheet of a nickel-titanium memory material that is configurable into a roll such that the suture anchor has a first configuration when positioned within the applicator and a second configuration after deployment from the applicator, wherein the second configuration has a geometric shape that is broader in at least one plane than the first configuration. The suture anchor also has a surgical suture threaded through an aperture of the body and retainably connected to the body by a knot in the suture or a ferrule crimped onto the suture, wherein the suture extends from approximately the middle of the body when in the second configuration.
Other aspects and embodiments of the expandable suture anchor will become apparent from the following description, the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
When using conventional T-tag fasteners with the technique shown in
Although the size of the cannulated needle 19 shown in
Recently, a number of medical devices have been developed that provide an auxiliary passageway along the outside of the endoscope. One example of a medical apparatus that provides an auxiliary endoscopic passageway may be found in U.S. patent application Ser. No. 10/440,957 (published as U.S. Pat. Pub. No. 2004/0230095), filed May 12, 2003, and assigned to Ethicon Endo-Surgery, Inc. The auxiliary passageway may be used, perhaps in combination with the working channel of the endoscope, for several purposes, such as to insert a suture anchor applicator for access to an internal wound site. It should be understood, therefore, that descriptions herein referring to the working channel of the endoscope also include using such an auxiliary passageway.
Outer tube 42 may be formed from an extruded polymer, a helically wound metallic wire or from other materials well-known in the art. Inner tube 40 may be formed from 19 gage stainless steel hypodermic tubing, for example, having an outer diameter of approximately 0.043 inches (1.09 millimeters) and a wall thickness of approximately 0.003 inches (0.076 millimeters). The distal end of inner tube 40 may be ground to form a cannulated needle 32 having a distal, penetrating tip 34. Alternatively, inner tube 40 may be formed from an alternate type of metallic or polymeric tube and attached to cannulated needle 32, such as by welding, crimping, gluing or other conventional method.
Penetrating tip 34 may be ground to have a “bi-angular” configuration as shown in
Inner tube 40 and needle 32 may include a channel 36 extending along a longitudinal axis 50 between the proximal and distal ends of applicator 30. At least one suture anchor 46 having a suture 48 attached thereto may be loaded in channel 36. An actuating element 38 may extend through channel 36 of applicator 30 for ejecting suture anchor 52 out of needle 32, as shown in
Outer tube 31 may be moved between an extended position for shielding tip 34 of needle 32 (
Expandable Suture Anchor
Numerous aspects of an expandable suture anchor are described herein. In general, the expandable suture anchor may be used for attaching a suture to any one of numerous soft tissues, including the wall of the gastrointestinal tract. The anchor may include a suture attached thereto and a body that is constrainable to a first configuration for deployment into the tissue and that is expandable when unconstrained to a second configuration for resisting pull-out from the tissue.
Anchor 52 may be formed from a biocompatible, spring material such as a stainless steel, a titanium alloy, a nickel-titanium memory metal (Nitinol), a polymer, or an absorbable polymer. Spring material shall be referred to herein as a material such that, a suture anchor formed from the spring material is biased to springably change from the first to the second configuration when not constrained.
Suture 54 and all the sutures described herein may be a surgical suture formed from convention surgical suture materials including, for example, cat gut, polypropylene, polyester and stainless steel. The suture size may be any one of the commonly used sizes for surgical procedures, including 2/0, 3/0 and 4/0 sutures.
As shown in
Suture 54 may extend from the middle portion of anchor 52 such that when suture 54 is drawn tightly after placement of anchor 52 through layers of tissue, anchor 52 reorients such that axis 64 is approximately perpendicular to suture 54 extending from the wound site, thereby providing a high resistance to pull-out from the tissue. If anchor 52 is positioned within tissue rather than in a body cavity, legs 60 also function to dig into the tissue when a tensile force is applied to suture 54, thereby helping anchor 52 reorient within the tissue such that suture 54 is securely attached to the tissue. The lengths L1 of legs 60 and the angles formed by legs 60 relative to axis 64 may be selected such that tissue retention forces are asymmetric when a tensile force is applied to suture 54, thereby helping anchor 52 to reorient within the tissue and increase the pull-out resistance.
In one aspect, the diameter of anchor 52 may be approximately 0.50 to 0.85 millimeters, or small enough to slide easily, for example, into a 19 gage, cannulated needle. The overall length of anchor 52 may be, but is not limited to, approximately five to 10 millimeters.
Anchor 68 is similar to anchor 52 of
Anchor 68 provides a high pull-out resistance from tissue when deployed either through tissue layers or within tissue layers. In the former, anchor 68 may orient itself to be approximately perpendicular to suture 70. In the latter, legs 80 of anchor 68 act like barbs and may dig into surrounding tissue. In addition, the spring-back of legs 80 helps to hold anchor 68 securely inside of needle 32 of applicator 30 (
Anchor 102 may include a suture 104 retained through a hole (hidden) by a knot 106. Alternately, suture 104 may be attached to anchor 102 by gluing, crimping or any one of a number of well known methods.
Self-Shielding Suture Anchor
As already described, a physician may fully penetrate the needle of a suture anchor applicator through tissue layers of an organ in order to deploy the suture anchor on the distal side of the tissue layers. The physician normally cannot see anatomical structures on the distal side of the tissue layers through the endoscope and therefore may accidentally injure nearby organs with the penetrating needle. A fifth aspect of a suture anchor 110, a “self-shielding” suture anchor, is provided to help prevent such accidental injury.
Still referring to
Since anchor 110 includes a penetrating tip 114, it is not necessary for the applicator of anchor 110 to also include a needle with a penetrating tip. For example, needle 32 of applicator 30 in
Anchor 110 is an exemplary embodiment of a self-shielding anchor. Those skilled in the art will appreciate that numerous other embodiments are possible, including a self-shielding anchor that is unitarily formed from a biocompatible material by an injection molding process.
All of the suture anchor aspects described herein and their equivalents, may be subjected to a secondary manufacturing process such as tumbling, bead blasting or electropolishing to remove sharp burrs or edges that may injure tissue or inhibit proper deployment into tissue. In addition, all of the suture anchor aspects may be coated with a second material in order to provide desirable properties that may facilitate the deployment of the anchor and/or improve the surgical outcome. For example, the suture anchor may be coated with a lubricious coating, a polymeric coating, a drug-releasing coating, an anti-bacterial coating or a colored coating to facilitate identification.
Suture Anchor Applicator
As may be seen in
An intermediate tube 222 may be movably and coaxially retained over inner tube 228. The distal end of intermediate tube 222 may include a radial flange 224. The proximal end of intermediate tube 222 may be operatively engaged to first actuator 208. The physician may operate first actuator 208 to move intermediate tube 222 between an extended position, in which flange 224 is distal to penetrating tip 114 of anchor 110, and a retracted position, in which flange 224 is proximal to tapered end 230 of inner tube 228. First actuator 208 may be provided with calibrations or a visual indicator such that the physician may position and hold intermediate tube 222 in any longitudinal position between the extended and retracted positions and know the maximum penetration depth of inner tube 228.
Still referring to
Tissue stop 206 may be formed such as by injection molding from a biocompatible polymer or metal. Tissue stop 206 may include at least one arm 216 that is approximately parallel to the longitudinal axis 240 when tissue stop 206 is in the collapsed configuration for easy passage through the working channel of an endoscope. Arm 216 may extend outwardly from longitudinal axis 240 when tissue stop 206 is in the expanded configuration, such that only the portion of applicator 200 distal to tissue stop 206 may penetrate tissue. As shown in
It would also be possible for proximal stop ring 220 to be fixed to intermediate tube 222 and distal stop ring 218 to be slidably retained on intermediate tube 222. Instead of outer tube 214, another type of force element, such as a wire (not shown) may be connected to distal ring 218 and extended through channel 229 to handle 200. The proximal end of the wire force element could be connected to second actuator 210. The physician could then move second actuator 210 in the proximal direction to change tissue stop 206 from the collapsed to the expanded configuration.
The longitudinal position of flange 224 may set a distance “D2” (
An alternate embodiment of applicator 200 may include a tissue stop that is formed from a spring material such that the tissue stop is in the expanded configuration when unconstrained. In such an alternate embodiment, the tissue stop may be attached to the distal end of an intermediate tube that the physician may move to any longitudinal position between an extended and a retracted position. An outer sheath may be provided on the shaft of the applicator such that the physician may move the sheath distally to slide over and collapse the tissue stop and may move the sheath proximally to uncover the tissue stop and allow it to expand. Calibrations may be provided on the actuator such that the physician can know the maximal penetration depth of the tip.
In
A method of endoscopically attaching a suture anchor to the tissue of a patient may include the following: A suture anchor applicator wherein the applicator includes a tissue stop movable between a collapsed and an expanded configuration and the applicator contains a suture anchor in a loaded position. The endoscopic portion of an endoscope is positioned in the patient to provide access and visualization of a wound in the tissue. While the tissue stop is in the collapsed configuration, the shaft of the applicator is introduced into the working channel of the endoscope. The distal end of the applicator is positioned near the tissue and the tissue stop is changed to the expanded configuration. The applicator is advanced distally such that the anchor and the distal end of the applicator penetrates into the tissue to approximately a maximal penetration depth as determined by the location of the tissue stop on the shaft of the applicator. The applicator is remotely actuated to deploy the suture anchor into the tissue, thereby attaching the suture anchor to the tissue with the suture attached thereto and extending through the penetrated tissue and the work channel. The applicator is withdrawn proximally through the working channel and removed from the endoscope.
The proximal end of sheath 402 may be operatively connected to a control on a handle (not shown) such that the longitudinal position of sheath 402 relative to inner tube 410 may be adjustable by the user. Using this control, distal end 414 may be extended to a position distal to penetrating tip 412 while the distal end of applicator 400 is advanced to the wound site and retracted to a position proximal to tip 412 when it is desired to penetrate tissue. Calibrations and/or a visual indicator may be provided on the handle to indicate the position of distal end 414 such that the user may know the approximate penetration depth of inner tube 410 into the tissue.
Although various aspects of expandable suture anchors, self-shielding suture anchors, suture anchor applicators and methods have been shown and described, it should be understood that modifications may occur to those skilled in the art.
Claims
1. An expandable suture anchor for use with an applicator, the suture anchor comprising a body formed from a biocompatible spring material such that the suture anchor has a first configuration when positioned within the applicator and a second configuration when deployed from the applicator, wherein the second configuration has a geometric shape that is broader in at least one plane than the first configuration.
2. The expandable suture anchor of claim 1, wherein the body has an approximately cylindrical shape defining a longitudinal axis when in the first configuration.
3. The expandable suture anchor of claim 2, wherein the body includes at least one leg that is springably deformable such that a portion of the leg extends further in an outwardly direction from the axis in the second configuration than in the first configuration.
4. The expandable suture anchor of claim 3, wherein the body is formed from a tubular material.
5. The expandable suture anchor of claim 2, wherein the body has a planar shape in the second configuration.
6. The expandable suture anchor of claim 5, wherein the body comprises a sheet that is configurable into a roll.
7. The expandable suture anchor of claim 5, wherein the planar shape is approximately a square shape.
8. The expandable suture anchor of claim 1, wherein the spring material includes at least one of a stainless steel, a titanium-nickel memory metal, a titanium alloy, a polymer, a cellulose material, a fabric and an absorbable polymer.
9. The expandable suture anchor of claim 1, further comprising a surgical suture connected to the body, wherein the suture extends from approximately the middle of the body when in the second configuration.
10. The expandable suture anchor of claim 9, wherein the suture is threaded through an aperture of the body and is retainably attached to the body by a knot in the suture or a ferrule crimped onto the suture.
11. The expandable suture anchor of claim 9, wherein the suture is fixedly attached to the body by gluing, welding, insert molding, deforming the body tightly onto the suture or a mechanical attachment.
12. The expandable suture anchor of claim 9, wherein the suture is formed from a conventional surgical suture.
13. The expandable suture anchor of claim 9, wherein the suture is approximately 20-200 centimeters long.
14. The expandable suture anchor of claim 1, wherein at least a portion of the suture anchor is coated with at least one of a lubricating coating, a polymeric coating, an anti-bacterial coating, a drug-releasing coating and a colored coating.
15. The expandable suture anchor of claim 1, wherein the body is formed to be normally in the expanded configuration such that the body is constrained in the first configuration when loaded within the applicator.
16. An expandable suture anchor for use with an applicator, the suture anchor comprising:
- a body formed from a nickel-titanium memory material such that the suture anchor has a first configuration when positioned within the applicator and a second configuration after deployment from the applicator, wherein the second configuration has a geometric shape that is broader in at least one plane than the first configuration, and wherein the body has an approximately cylindrical shape defining a longitudinal axis when in the first configuration, and wherein the body includes at least one leg that is springably deformable such that a portion of the leg extends further in an outwardly direction from the axis in the second configuration than in the first configuration; and
- a surgical suture threaded through an aperture of the body and retainably attached to the body by a knot in the suture or a ferrule crimped onto the suture to the body, wherein the suture extends from approximately the middle of the body when in the second configuration.
17. The expandable suture anchor of claim 16, wherein the suture is formed from a conventional surgical suture.
18. The expandable suture anchor of claim 17, wherein the suture is approximately 20-200 centimeters long.
19. The expandable suture anchor of claim 16, wherein at least a portion of the suture anchor is coated with at least one of a lubricating coating, a polymeric coating, an anti-bacterial coating, a drug-releasing coating and a colored coating.
20. The expandable suture anchor of claim 16, wherein the body is formed to be normally in the expanded configuration such that the body is constrained in the first configuration when loaded within the applicator.
Type: Application
Filed: Nov 15, 2005
Publication Date: May 17, 2007
Inventor: Sean Conlon (Loveland, OH)
Application Number: 11/274,358
International Classification: A61B 17/04 (20060101);