Endoscopic device with independently actuated legs

The present invention relates to endoscopic clips with multiple independently-controlled legs. The present invention also relates to a method for using a clip with multiple independently actuated legs. The clips and methods of the present invention may be used, for example and without limitation, for repairing tears and other defects endoscopically.

FIELD OF THE INVENTION

The present invention relates to endoscopic clips with legs that may be advanced and controlled independently of each other, as well as methods of using the clips. The clips and methods of the present invention may be used, for example, to repair or suture tears or other defects endoscopically or in other environments where access is limited to a small incision or opening. The device and methods also may be used for approximation and fixation of tissue or other material.

BACKGROUND OF THE INVENTION

Less invasive surgical procedures can reduce patient trauma, and as a result, may reduce the length of hospital stays, as well as hospital and medical costs. Endoscopic surgery recently has provided a significant opportunity to reduce the invasiveness of numerous surgical procedures. This type of surgery involves the use of an endoscope, an instrument that permits the visual inspection and magnification of cavities within the body. Endoscopes may be flexible, semiflexible, or rigid. An endoscope may be inserted through a small surgical incision to view organ structures in a body cavity or through a natural orifice such as the mouth, anus, bladder, and vagina to view lumen-containing organs in the gastrointestinal, respiratory, and genital and urinary tracts. Endoscopes have channels for irrigation, suction, and the insertion of accessory instruments when a surgical procedure is performed

During a surgical procedure, surgeons often are required to repair or reconstruct a tear or defect or otherwise approximate or fixate tissue or other material by suturing. However, the ability to suture through an endoscope technically is limited. In response to this problem, surgeons have sought alternatives to conventional suturing techniques that are more appropriate for use through an endoscope. Among these alternatives include the use of endoscopic clips.

While the use of endoscopic clips has alleviated some problems associated with suturing through the end of an endoscope, there is still room for improvement in their design and use. For instance, as presently used, the “legs” of clips are joined at their proximal ends. This configuration requires the distal ends of the legs to have a fixed distance and relationship between them. These fixed relationships limit a surgeon's ability to position the clip appropriately in relation to a particular tear or defect or other area in need of treatment. For instance, these clips may not be able to address a tear or defect with certain curves or angles and may not be able to span the width of a larger tear or defect. Further, because the proximal ends of the legs are joined, a surgeon may not be able to adjust the positioning of one leg of the clip without affecting the positioning of the second leg. Positioning also may be limited because the clip may not be properly oriented when it is placed within the actuating jaws of the cannula, or the clip may slip out of alignment during application. Finally, the legs of presently-used clips must be actuated and anchored at the same time. If unequal pressure is applied to the legs during anchoring, scissoring of the legs may occur and further tissue damage may result.

SUMMARY OF THE INVENTION

The present invention solves many of the described problems associated with presently-used endoscopic clips. The present invention may solve these problems by providing an endoscopic clip with independently-controlled legs that are not joined at their proximal ends.

One embodiment of the present invention may be a device comprising an outer tube with a proximal end and a distal end; a pusher tube assembly comprising an inner tube with a proximal end and a distal end and an end cap secured to the distal end of the inner tube; a clamp collar within the distal end of the inner tube; legs, each having a proximal end and a distal end; a retainer located proximally to the clamp collar with slots that allow passage of the legs; and an actuating member connected to the proximal end of the legs. Each leg may have an outwardly-oriented tab. The distal ends of the legs may be located, before deployment, at the distal end of the inner tube but proximal to the clamp collar. The legs, actuating members and retainer may reside within the inner tube. The outer tube and the inner tube may be connected to a proximal handle that may actuate each leg independently through a separate control cable connected to the proximal end of each leg's actuating member. The distal end of the legs may comprise a hook having a back end. The leg or hook may have a barb. The legs or hook may have a sharpened end. This sharpened end may be protected when the legs have been extended from the device and are in a closed and locked position. The back end of the hook may be angled outwardly within the inner tube.

In one embodiment of the present invention the actuating members may be guide blocks. In addition, the proximal handle may rotate the inner tube independently of the outer tube. The handle also may control the inner tube and the actuating members of the legs. The clamp collar may have slots that allow passage of the legs. The device may comprise two, three, four, or more legs.

The device may be used to interlock the legs of the present invention and the interlocked legs may be released. The legs may have a weakened portion that can break and separate the legs from the device once the legs are extended from the endoscopic device and in a closed and locked position.

The inner tube may be a coiled stainless steel tube. The legs may be made from a spring material. The outer and/or inner tubes may have a coil toward their distal ends. The control cables may, in one specific embodiment, have a diameter of about 0.50 mm. The outer tube may, in one specific embodiment, have an outer diameter of about 2.5 mm. The outer tube may, in one specific embodiment, have an inner diameter of about 2.0 mm. The inner tube may, in one specific embodiment, have an inner diameter of about 1.5 mm. The legs may, in one specific embodiment, be formed with a wire with a diameter of about 0.25 mm prior to hardening.

The present invention further comprises a method of using the above described device for endoscopically joining target material. This method comprises extending a first leg from said inner tube; engaging target material with said distal end of said first leg; extending a second leg from said inner tube; engaging target material with said distal end of said second leg; drawing said legs together into an interlocked position; and releasing said legs in said interlocked position from said device. The method further comprises repeating said extending and said engaging with additional legs as needed. Extending and engaging of the legs may be accomplished by sliding the actuating members connected to the proximal ends of the legs. The engaging step may further be accomplished by hooking and/or anchoring. The drawing step may be accomplished by sliding the inner tube over the extended and engaged legs. While the extension and engagement of the legs has been described as occurring sequentially, the extension and engagement of the legs also may occur simultaneously. The releasing step may comprise applying a force to the legs through the actuating members that may break the legs at the weakened portion of the legs.

The target material to be joined by the method may include, for example and without limitation, tissue, tissue surrounding a tear, tissue on alternate sides of a tear and/or a tissue defect. The method may be used, for example and without limitation, to repair a tissue defect, repair a tissue tear, anchor tissue or approximate or fixate tissue or other material.

DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS

It is to be understood that the present invention is not limited to the particular methodology, compounds, materials, manufacturing techniques, uses, and applications, described herein, as these may vary. It is also to be understood that the terminology used herein is used for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention. It must be noted that as used herein and in the appended claims, the singular forms “a,” “an,” and “the” include the plural reference unless the context clearly dictates otherwise. Thus, for example, a reference to “a leg” or “a clip” is a reference to one or more legs or clips and includes equivalents thereof known to those skilled in the art.

The term “patient,” as used herein, comprises any and all organisms and includes the term “subject.” “Patient” may refer to a human or any other animal.

In the following description it should be noted that directional terms such as “distal” and “proximal” are used relative to each other and do not refer to positions or orientations relative to an external frame of reference. Also, “locked” and “interlocked” are coextensive in meaning.

The terms “endoscope” or “endoscopic” refer not only to conventional endoscopes and endoscopic procedures, but also to any rigid, semi-rigid, or flexible optical instrument for use in visual examinations where access is limited to a small incision or opening. Generally, such examinations will occur in the human body, however, the use of the terms is not so restricted. References to endoscopes and endoscopic procedures must be understood also to encompass procedures in all organisms, living or dead, as well as, the examination of inanimate objects through small openings. Endoscopes and endoscopic procedures also must be understood to include laparoscopic devices and laproscopic procedures. The term “endoscope” also includes echo-endoscopes, which may include an ultrasound transducer at, for example, the tip of the device.

The term “material” refers to the substrate that is engaged by the legs of the present invention. Often the material engaged will be tissue within a body; however use of the term is not so limited.

The terms “join or joining” include repair of a tear or defect in any material that may be engaged, hooked or pierced by the legs of the present invention and specifically includes closure of tears or other defects and apposition of tissue or other material, analogous to that caused by conventional suturing or stapling, in endoscopic procedures, as well as grafting healthy tissue or other material onto areas of defective tissue or other material. The term also includes traversing and/or anchoring one or more layers of tissue that can be accessed endoscopically, such as, for example and without limitation, the wall of a hollow or solid organ, duct, vessel or soft tissue structure.

FIG. 1throughFIG. 11depict exemplary devices and methods of the present invention. These devices and methods are depicted and described herein in order to better explain the invention. It will be understood that the devices and methods shown are representative only, and that devices of other configurations, sizes and styles are within the scope of this invention.

Referring to the Figures,FIG. 1depicts an isometric view of the distal end of the device of the present invention with two legs70advanced. The legs70are shown protruding from the distal end of the outer tube40. In the embodiment shown inFIG. 1, the legs70have hooks on their distal ends. In another embodiment of the present invention, the legs70may include hooks on their distal ends as well as a barbed anchoring member on the distal portion or tip of the leg. In another embodiment of the present invention, the legs70may include hooks on their distal portion or end as well as multiple barbed anchoring members. In another embodiment of the present invention, the legs70may lack the hook on their distal ends and instead have one or more barbed anchoring member on the distal tips of the legs. The legs70within a given device may have any combination of the hook and barbed anchoring member configurations described above. For instance, in one embodiment, all legs70may have the same configuration. In another embodiment, the legs70within a device may have different configurations.

In addition to the legs70of the device,FIG. 1depicts two control cables50extending from the proximal end of the outer tube40. The outer tube40may extend the full length of the device. The control cables50may be connected or connectable, at their proximal end, to a control in a hand piece (not shown). The outer tube40also may be connected or connectable to a hand piece on its proximal end.

FIG. 2is a longitudinal section view of a specific embodiment of the present invention. This view shows the control cables50connected to actuating members (guide blocks60in this Figure) that may be attached to the proximal ends of the legs70of the present invention, all within an inner tube20located within the outer tube40. The inner tube20also has an end fitting30connected to its distal end that contacts the proximal end of the clamp collar100. The inner tube20and end fitting30together form a pusher tube assembly (labeled as10inFIG. 5) that may advance the clamp collar100during deployment of the clip. In this configuration, the device may be fed through the working channel of an endoscope. The control cables50can transmit axial tension or compression to the guide blocks60in part due to support provided by the inner tube20.

FIG. 3is a longitudinal section view of a specific embodiment of the device of the present invention. One leg70is depicted as fully advanced while a second leg70is depicted as partially advanced.FIG. 3also shows the outer tube40. While the embodiment depicted in this Figure depicts two legs70, the device of the present invention is not limited to this embodiment. In another embodiment of the present invention the device may have two or more legs70. In another embodiment, the device of the present invention may have three or more legs70. In another embodiment, the device of the present invention may have four or more legs70. In one embodiment of the present invention, all legs70may be located at the distal end of the device. In this embodiment, the guide blocks60may be half cylinders if there are two legs70, third cylinders if there are three legs70, quarter cylinders if there are four legs70and so forth. It is contemplated that each portion of the guide block60may have a control cable50attached to its proximal end. In another embodiment of the present invention, the legs70may be grouped into pairs of two, with the first pair located most distally, the second pair proximal to the guide blocks60of the first pair, the third pair proximal to the guide blocks60of the second pair and so forth. In this embodiment, each leg70of a pair may have a half cylinder guide block and the control cables50may be configured to travel along the outer circumference of the inner tube20to allow the successive pairs of legs70.

When two legs70are included in an embodiment of the present invention or legs70are included as pairs, the guide blocks60may be half cylinders that may slide axially relative to the longitudinal axis of the device. The guide blocks60may have flat sides that may face each other within the inner tube20. The length of the guide blocks60may be set so that the maximum relative displacement of the guide blocks60is less than the length of the guide blocks60themselves. In this configuration, the guide blocks60may remain mated along their faces.

FIG. 4depicts two legs70fully advanced and in an unlocked configuration.FIG. 4also shows guide blocks60attached to the proximal ends of the legs70, a retainer110that may be an elastomeric part of cylindrical shape with grooves that run its full length, and the clamp collar100, which may be a tubular ring with slots that nests in the distal end of the device. The slots of the clamp collar100allow passage of the legs70during clip deployment.FIG. 4also shows tabs120that may be found on the legs70of the present invention. Once the legs70have been advanced and engaged, the clamp collar100of the present invention may be advanced by the end cap30until the clamp collar100contacts these tabs120.FIG. 4also depicts the outer tube40and the control cables50.

FIG. 5is a longitudinal section view of one specific embodiment of the device of the present invention. In this Figure, two legs70have been advanced, and the clamp collar100also has been advanced to bring the legs into a locked position. The pusher tube assembly10(comprised of the inner tube20and end cap30) pushes the clamp collar100toward the distal ends of the legs70. Advancement of the clamp collar100may bring the legs70together into an interlocked position as shown inFIG. 5. If the legs70have been positioned properly, once pulled into the locked position by the clamp collar100, they generally, for example, will have pulled the sides of a tear or defect together.FIG. 5also depicts the outer tube40, control cables50, guide blocks60and the retainer110.

FIG. 6is a close-up, longitudinal section view of a clip in its locked position. This Figure depicts the legs70of the clip after they have been drawn together by advancement of the clamp collar100to the tabs120on the legs70. This Figure also depicts the slots105of the clamp collar100that accept the curved area90of the legs70as well as the retainer110.

FIG. 7is a detailed plan view of an exemplary leg70of the present invention. The leg70, in this example, includes a hook on its distal end, a tab120and a curved area of the leg90. In one embodiment, the curved area90of the leg70may contain a weakened zone80. Stress within the curved area90of the weakened zone80may be intensified by bending moments produced by eccentric loading in the curved area90of the leg70.FIG. 8depicts weakened zone80in greater detail.

FIG. 9is a detailed isometric view of an exemplary clamp collar100with slots105that allow passage of the legs70of the present invention.

FIG. 10is a detail isometric view of an exemplary retainer110, showing the grooves115that run the length of the retainer.

FIG. 11is an exemplary leg70with a hook and a barbed anchoring member135. The barbed anchoring member135, in this embodiment, as shown, is positioned at the end of a hook at the distal end of a leg70. A barbed anchoring member135may be included to improve the security of tissue or other material engagement. For example, once engaged with material, it is possible that a leg70may disengage when such disengagement is not directed or intended. With a barbed anchoring member135, however, it may be less likely for the leg70to become disengaged because the barbed anchoring member135may serve to further hold the tissue or other material.

The devices of the present invention specifically may be used in a broad variety of applications where endoscopic joining of body tissue or other material is appropriate, for example suturing, stapling, or tissue or other material apposition. When used within a body, the devices of the present invention may be used, for instance, to join an unwanted separation of soft tissue that results from, for example and without limitation, injury, disease, or surgical incision. The devices and methods of the present invention also may be used in joining, or for example grafting, healthy tissue or other material onto areas of defective tissue or other material. Also, the devices and methods of the present invention may be used to approximate and/or fixate tissue or other material within a body. Further, the devices may be used to join, for example traversing and/or anchoring, one or more layers of tissue that can be accessed endoscopically, such as, for example and without limitation, the wall of a hollow or solid organ, duct, vessel or soft tissue structure.

The device of the present invention may offer various advantages over known devices. For instance, the independent nature of the legs70may allow them to be deployed and engaged without interfering with each other, and may also allow the legs to reach across a greater span of tissue or other material and therefore close larger tears or defects than previously possible. The independent nature of the legs70also may allow for better positioning during endoscopic procedures. Finally, the various leg70configurations may allow a surgeon to choose the configuration that may address and hold a given tear or defect more securely.

In use, the device of the present invention may be fed through the working channel of an endoscope. Once the device is deployed through the endoscope, it may be positioned near a tear or other defect. Positioning around a tear or defect may be improved by rotating the inner tube20to align the legs70in accordance with the orientation of the tear or defect by a control in the hand piece. Once positioning is complete, a leg70may be advanced and maneuvered through manipulation of its control cable50and guide block60so as to engage tissue or other material on one side of the tear or defect. For instance, if a hook configuration is used, the tissue or other material may be hooked by the first leg. A second leg70may then be advanced and maneuvered through its control cable50and guide block60to engage a different piece of tissue or other material surrounding the tear or defect. The amount of extension of the second leg relative to the extension of the first leg may be adjustable. This feature of the devices of the present invention allows the device to address tears or defects of various sizes, shapes and orientations. Additional legs70may continue to be advanced as needed to address the tear or defect. While use of the present invention generally is described in terms of extending and engaging the legs70of the device sequentially, it also is contemplated that the legs70may be (i) advanced simultaneously and engaged with the tissue or other material sequentially, (ii) advanced sequentially and engaged simultaneously or (iii) advanced and engaged simultaneously.

Once a sufficient number of legs have been advanced and engaged with the tissue or other material surrounding the tear or defect, the quality of engagement between each leg and the tissue or other material may be tested by applying a light tension to each leg by pulling each control cable50. Once satisfied with the anchoring of the legs within the tissue or other material, the pusher tube assembly10(inner tube20and end cap30) may push the clamp collar100forward until the clamp collar100contacts the tabs120on the legs70. The advancement of the clamp collar100may draw the deployed legs70back together into a closed and locked position, thus drawing the various segments of tissue or other material surrounding a tear or other defect into apposition. If necessary, the clamp collar100also may be undeployed. For instance, if one or more of the deployed legs is not positioned sufficiently or has become dislodged or disengaged from the tissuse or other material, the collar100may be undeployed and the leg or legs may be repositioned and/or reengaged with the tissue or other material.

Once advancement of the clamp collar100has pulled the legs70into a closed and locked position, thus leading to a closure of a tear or defect or apposition of tissue or other material, the legs70may be broken to free the actuated clip from the endoscopic device. The legs70may be broken at the weakened zones80of the curved areas90by applying an increasing load to the control cables50until a sudden loss of tension is detected. Because the hook tab120, in the activated position, abuts the pusher tube assembly10, all forces placed on the legs70during breaking should be absorbed into the device and no significant forces should be transmitted to the tissue or other material surrounding the clip. After separation from the endoscopic device, the endoscope may be removed while the clip may be left in place. In this manner, the devices of the present invention may effectively lead to the closure of tears or other defects and apposition of tissue or other material, analogous to that caused by conventional suturing or stapling.

The embodiments of the present invention may be configured and controlled by a proximal handle that may control the extension and retraction of the independent legs70as well as rotate and extend and retract the inner tube20independently of the outer tube40. In one embodiment of the present invention, the proximal handle of the device may be connected or connectable to the inlet port of the endoscope or echo-endoscope. Examples of such endoscopes are found, for example, in U.S. Pat. No. 6,638,213; No. 6,614,595; and No. 6,520,908. In another embodiment, the proximal handle of the device of the present invention may be screwed and thereby securely anchored into the inlet port of the instrumentation channel of the endoscope using a Luer lock mechanism.

The control cables50of the present invention may be housed within the inner tube20of the present invention. These control cables50may independently control the extension and retraction of the legs70of the present invention. In one embodiment of the present invention, the control cables50may be flexible in bending. In another embodiment, the control cables50may be metal cables. In another embodiment, the control cables50of the present invention may be solid stainless steel wire. In another embodiment the control cables50may have a diameter of about 0.50 mm. Further, in one embodiment of the present invention, the control cables50may travel to the proximal handle through the approximate center of the inner tube20. In another embodiment, the control cables50may travel to the proximal handle towards the outer circumference of the inner tube20. The control cables50may be connected or connectable to the proximal handle.

The outer tube40of the present invention may serve several functions. It may protect the instrumentation channel in the endoscope from the device of the present invention, as well as to protect the device itself. The outer tube40may reinforce the device and also may help to guide and position the device appropriately, even after the device has moved beyond the passage provided in the endoscope. The outer tube40also may serve to dilate or enlarge a tissue penetration tract. In one embodiment of the present invention, the outer tube40may be separate from the rest of the device of the present invention. Thus, in this embodiment, the outer tube40may be moved independently of the rest of the device. In another embodiment of the present invention, the outer tube40be made of an impenetrable material. In another embodiment of the present invention, the outer tube may be a flexible plastic tube. In another embodiment of the present invention, the outside diameter of the outer tube40may be of an appropriate size to allow for easy insertion into the working channel of most endoscopes. In another embodiment of the present invention, the outside diameter of the outer tube40may be about 2.5 mm. In another embodiment, the inside diameter of the outer tube40may be about 2.0 mm. The outer tube40may be connected or connectable to the proximal handle.

The pusher tube assembly10of the present invention may comprise an inner tube20that may reside within the outer tube40, as well as an end cap30that may be fitted and secured to the distal end of the inner tube20. This pusher tube assembly10may be similar to those used in many endoscopic accessories. In one embodiment of the present invention, the pusher tube assembly10may be flexible, but also may be able to support axial compressive loads when restrained in the outer tube40. In another embodiment of the present invention, the inner tube20may consist of a coiled stainless steel tube. In another embodiment of the present invention, the pusher tube assembly10may have an outside diameter of about 1.65 mm. In another embodiment of the present invention, the pusher tube assembly10may have an inside diameter of about 1.52 mm. The inner tube20of the pusher tube assembly10may be connected or connectable to the proximal handle.

Ligating clips generally are classified according to their geometric configuration as either symmetric or asymmetric clips. Symmetric clips are generally “U” or “V” shaped clips that are substantially symmetrical about a central, longitudinal axis extending between the legs of the clip. By contrast, asymmetric clips lack an axis of symmetry. Because the legs70of the clips of the present invention are not joined at their proximal ends, the clips of the present invention can be symmetrical or asymmetrical in use. This feature of the legs70of the present invention allows the clips to address tears or other defects of various shapes, sizes and orientations.

When the legs70of the present invention include a barbed anchoring member135, in one embodiment, the barbed anchoring member135may include a pointed conical tip. In another embodiment, the barbed anchoring member135may pierce one or more layers of tissue or other material in a pre-expansion form before expanding into an anchoring shape.

The clips of the present invention can be made of any material using conventional fabrication methods. For instance, materials that may be used in accordance with the present invention may include conventional biocompatible materials such as various metals, plastics, elastomers, and bioabsorbable polymeric materials, as well as stainless steel, and other surgical alloys of steel. In general it may be valuable to avoid using materials that are likely to cause allergic reactions or inflammation, unless such a result is desired. Examples of bioabsorbable polymeric materials that may be used in accordance with the present invention include, for example and without limitation, homopolymers and copolymers of glycolide, lactide and para-dioxanone, trimethylene carbonate and epsilon-caprolactone. When made of a biooabsorbable polymeric material, the clips of the present invention may be made by injecting a suitable polymer melt into an appropriately designed mold at process conditions conventionally employed for such polymer systems. After the polymer melt cools, the molded polymer shaped in the mold to meet the design criteria of the clip may be released from the mold. The molded clip can then be sterilized using conventional methods to render the clip suitable for surgical applications. In one embodiment of the present invention, the clips may be made of a spring hardened stainless steel such as, for example, 17-7 PH in the CH900 condition (hardened). In another embodiment of the present invention, the clip may be formed of wire with a diameter of about 0.25 mm prior to hardening.

In various embodiments of the present invention, the legs70of the clips may have weakened zones80to allow the clips to separate from the endoscopic device once positioned and drawn into a locked position. In one embodiment of the present invention, the weakened zone80may be created by reducing the diameter of the leg wire. In another embodiment, the weakened zone may be designed to fail when a tension load of about one pound is applied to the legs70through the control cables50and actuating members60.

Other embodiments and advantages of the present invention will be apparent to those skilled in the art from consideration of the specification and the practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only.