BACKGROUND OF THE INVENTION1. The Field of the Invention
The present invention relates to medical devices usable to repair a fistula. More particularly, the present invention relates to medical devices having distal flexibility and/or controllability to repair a fistula.
2. The Related Technology
In medicine, a fistula is an abnormal connection or passageway between two organs or vessels that normally do not connect. Usually, a fistula is an abnormal passageway between two such organs or vessels, where a first body lumen thereby is abnormally connected to a second body lumen (e.g., organ to organ, organ to vessel, and/or vessel to vessel). The fistula itself is often not well defined and can be represented as a tear, opening, or hole in the tissue so as to have two different openings.
Fistulas can be malformations within the body with serious health consequences, and may even lead to death. Often, the body fluid contained in one body organ or lumen can pass through the fistula to another body organ or lumen. Such passage of body fluids can contaminate or cross-contaminate the body lumens when the fluids should not be passed therebetween. Also, a fistula in a vessel can lead to unfavorable blood deposits in an adjacent lumen or organ.
Some fistulas can be caused by disease. For example, inflammatory bowel diseases, such as Crohn's disease and ulcerative colitis, are the leading causes of anorectal, enteroenteral, and enterocutaneous fistulas. A person with severe stage-3 hidradenitis suppurativa may also develop fistulas.
Some fistulas can be an unfortunate consequence of a medical procedure, where the fistula forms during the implementation of the medical procedure. For example, complications from gallbladder surgery can lead to a biliary fistula. Also, radiation therapy can lead to a vesicovaginal fistula. However, an intentional arteriovenous fistula can be deliberately created in some instances as part of a therapy.
Some fistulas can be caused by trauma. For example, head trauma can lead to perilymph fistulas, whereas trauma to other parts of the body can cause unwanted arteriovenous fistulas. Obstructed labor can lead to vesicovaginal and rectovaginal fistulas. An obstetric fistula develops when blood supply to the tissues of the vagina and the bladder and/or rectum is cut off during prolonged obstructed labor. At some point, the tissues can die and a hole forms in the tissue through which urine and/or feces pass uncontrollably. Vesicovaginal and rectovaginal fistulas may also be caused by trauma.
Fistulas need to be repaired because they are painful and can cause secondary ailments from certain body fluids or other substances passing into a conduit, lumen, or other body cavity or tissue in which the body fluid does not belong. This can include urine passing into the vaginal or colon conduits, food or drink passing into the lungs, and blood passing from a vessel into another type of body conduit, such as an airway. Currently, fistulas are difficult to fix and require invasive surgery where the fistula is manually stitched closed. Often, surgeries that fix fistulas actually require forming an incision in a patient larger than the actual fistula itself, which is problematic because the incision also has to heal and is susceptible to infection from the surrounding environment and from the fistula itself.
Surgery is often required to ensure adequate drainage of the fistula so that pus may escape without forming an abscess. Various surgical procedures are commonly used to close a fistula, and utilize a common suture to stitch the fistula closed. For example, a fistulotomy can include placement of a seton, which is a cord that is passed through the path of the fistula to keep it open for draining. Also, an endorectal flap procedure can be performed where healthy tissue is pulled over the internal side of the fistula to keep feces or other material from reinfecting the channel. Additionally, treatments can include filling the fistula with fibrin glue, or plugging it with plugs made of porcine small intestine submucosa or other biocompatible substance. Surgery for anorectal fistulae is not without side effects, including recurrence, reinfection, and incontinence. The limited space available during the surgical procedure complicates the ability to properly stitch the fistula closed.
BRIEF SUMMARY OF THE INVENTIONThe present invention includes a medical device configured to apply a closure element to tissue surrounding a fistula for repairing the fistula. The fistula can be any type of fistula has an abnormal channel from one body part to another body part (e.g., organ to organ, organ to vessel, vessel to vessel, etc.). The medical device of the present invention can be configured to apply a closure element to tissue adjacent to a fistula to repair any type of fistula at any location within the body of a subject. Examples of fistulas that can be repaired with the present invention include anorectal fistulas, enteroenteral fistulas, enterocutaneous fistulas, vesicovaginal fistulas, arteriovenous fistulas, perilymph fistulas, rectovaginal fistulas, ureterocolon fistulas, and the like.
In one embodiment, the present invention can include a medical device for delivering a closure element to tissue within, proximal, defining, and/or adjacent to a fistula of a subject so as to close and repair the fistula. The medical device can include a closure element, a shaft, a carrier assembly, and controller systems. The closure element can have tissue-grabbing members, and can be configured for being deployed into tissue within and/or adjacent to a fistula so as to close and repair the fistula. The shaft can have a distal end, proximal end, and a sufficient length and flexibility at a selected portion to be inserted into a natural opening or incision that communicates with the fistula, and be controllably delivered to the fistula and placed in a manner such that the distal end of the medical device can be placed at or within the fistula. Such placement can allow for the closure element to be applied and repair the fistula.
The shaft can include a carrier assembly having a plurality of members cooperatively configured for retaining the closure element within the carrier assembly. The carrier assembly can be configured with a garage for retaining the closure element, and selectively controllable members for deploying the closure element from the carrier assembly. The carrier assembly can include a proximal end and a distal end, where the distal end can have sufficient flexibility so as to be capable of being pointed at or inserted into the fistula. A controller system can be configured as a delivery controller and can be operably coupled to the distal end of the shaft. The delivery controller can be configured for controlling the delivery and placement of the distal end (e.g., garage) of the shaft at or within the fistula.
A controller system can be configured to be capable of selectively deploy the closure element by being operatively coupled to the carrier assembly and/or members of the carrier assembly that can facilitate deployment of the closure element. The deployment controller system can be configured for controlling a plurality of members in the carrier assembly so as to deploy the closure element from the garage and into the tissue within and/or adjacent to the fistula so as to repair the fistula.
In one embodiment, the medical device can further include a locator assembly and a corresponding controller system. The locator assembly can have a distal end and a proximal end, where the distal end can have a locator configured for locating the fistula. For example, the locator can include a selectively expandable locator members, such as locator wings, that are configured for expanding to a diameter sufficient for contacting the tissue within and/or adjacent to the fistula such that the location of the fistula can be identified. A controller can be configured to control the locator assembly so as to be capable of locating the fistula and/or tissue adjacent, within, or defining the fistula.
The medical device can be configured in accordance with at least one of the following characteristics: the outer diameter of the shaft and/or carrier assembly can from about 0.2 cm to about 1 cm, more preferably from about 0.3 cm to about 0.75, and most preferably from about 0.4 cm to about 0.6 cm, or larger than about 0.17 inches. However, the outer diameter could be smaller such as about 0.01 cm, 0.05, or 0.01 cm as well as larger to about 1.5 cm, 2 cm, or 4 cm, if feasible. The length of the shaft and/or carrier assembly can vary greatly depending on the access point in the body and the corresponding position of the fistula. For example, the length can be longer than about 5 cm, between about 10 cm to about 200 cm, more preferably about 20 cm to about 150 cm, and most preferably about 30 cm to about 100 cm.
The shaft can include a distal end portion as a selected portion having flexibility; controlling members for controlling the deflection or bending of the selected portion; the shaft can include components of an endoscope such that the medical device can function as an endoscope; the distal end portion can be flexed, bent, or deflected such that the tip is at an angle of at least about 45, about 90, about 120, or about 180 degrees with respect to the shaft; the closure element can be one of a star closure element, collapsible tubular closure element, self-rolling closure element, reverse closure element, clam closure element, or combinations thereof.
The locator can have a length of at least about 0.25 cm, between about 0.3 cm to about 3 cm, more preferably about 0.4 cm to about 2 cm, and most preferably about 0.5 cm to about 1 cm. The locator can include at least one, two, three, four or more locator wings, said locator wings can have an expanded diameter of at least about 0.25 cm, between about 0.3 cm to about 3 cm, more preferably about 0.4 cm to about 2 cm, and most preferably about 0.5 cm to about 1 cm. The locator assembly can be configured to collapse and withdraw from the fistula as the closure element is deployed. Alternatively, the locator assembly can be pulled back through the closure element once the closure element is deployed. The shape-memory of the closure element allows the locator assembly to be pulled through an aperture of the closure element so as to deform the closure element, and the closure element can then revert to a substantially planar orientation to closure the vessel.
In one embodiment, the present invention can include a method for delivering a closure element into tissue within and/or adjacent to a fistula of a subject so as to close and repair the fistula. The method can include the following: inserting a distal end of a medical device configured to repair a fistula into a natural opening or incision in the subject, the distal end having a garage retaining a closure element configured for being deployed into tissue within and/or adjacent to a fistula so as to repair the fistula; delivering the distal end and garage to the fistula; and deploying the closure element into tissue within and/or adjacent to a fistula so as to repair the fistula.
In one embodiment, the method can further include flexing, bending, or deflecting the distal end portion during the delivering such that the tip is at an angle of at least about 45, about 90, about 120, or about 180.
In one embodiment, the method can further include: inserting a locator into the fistula, the locator having selectively expandable locator wings configured for expanding to a diameter sufficient for contacting the tissue within and/or adjacent to the fistula such that the location of the fistula can be identified; expanding locator wings of the locator such that the locator wings contact the tissue within and/or adjacent to the fistula; and identifying the locator to be at or within the fistula to locate the fistula. Also, the method can further include the following: collapsing the locator wings; and withdrawing the locator from the fistula as the closure element is deployed.
These and other embodiments and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGSTo further clarify the above and other advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
FIG. 1A is a schematic representation of a medical device being delivered through a lumen to a fistula.
FIG. 1B is a schematic representation of a flexible portion of the medical device being bent so as to point toward the fistula.
FIG. 1C is a schematic representation of a locator being extended from the medical device into the fistula.
FIG. 1D is a schematic representation of locator wings of the locator being expanded so as to contact and locate the fistula.
FIG. 1E is a schematic representation of a closure element being applied to tissue adjacent and/or within the fistula.
FIG. 1F is a schematic representation of the closure element closing with tissue-grabbing members pulling the tissue together to repair the fistula.
FIG. 1G is a schematic representation of another embodiment of a closure element repairing a fistula.
FIG. 1H is a schematic representation of another embodiment of a closure element repairing a fistula.
FIG. 1I is a schematic representation of a repaired fistula.
FIG. 2A illustrates an embodiment of a medical device having a locator assembly.
FIG. 2B illustrates the locator assembly ofFIG. 2A having locator wings in an unexpanded state.
FIG. 2C illustrates the locator assembly ofFIG. 2B having locator wings in an expanded state.
FIG. 2D illustrates a proximal end region of the locator assembly ofFIG. 2A that has controllers.
FIG. 3A illustrates an embodiment of a carrier assembly for carrying a closure element in a medical device.
FIG. 3B illustrates an embodiment of a carrier member for the carrier assembly ofFIG. 3A.
FIG. 3C illustrates an embodiment of a pusher member for the carrier assembly ofFIG. 3A.
FIG. 3D illustrates an embodiment of a cover member for the carrier assembly ofFIG. 3A.
FIG. 3E illustrates an embodiment of a support member for the carrier assembly ofFIG. 3A.
FIGS. 4A-4C illustrate different cross-sectional side views of an embodiment of a medical device configured to deliver a closure element to repair a fistula.
FIG. 4D illustrates a detailed cross-sectional side view of a triggering system of the medical device.
FIG. 5A illustrates the medical device ofFIGS. 4A-4D as the carrier assembly ofFIG. 3A moves distally from an initial predetermined position.
FIG. 5B illustrates the medical device ofFIGS. 4A-4D as the carrier assembly reaches a first predetermined position.
FIG. 5C illustrates the medical device ofFIGS. 4A-4D as the carrier assembly reaches a second predetermined position.
FIG. 5D illustrates the medical device ofFIGS. 4A-4D as the carrier assembly is bent in a first direction.
FIG. 5E illustrates the medical device ofFIGS. 4A-4D as the carrier assembly is bent in a second direction.
FIG. 6A illustrates a top view of a closure element in a natural, planar configuration and with a natural cross-section for use with the apparatus ofFIG. 1.
FIG. 6B illustrates a side view of the closure element ofFIG. 6A.
FIG. 6C illustrates a top view of the closure element ofFIGS. 6A-6B after a natural cross-section of the closure element has been reduced.
FIG. 6D illustrates a side view of the reduced closure element ofFIG. 6C.
FIG. 6E illustrates a side view of the reduced closure element ofFIGS. 6C-6D as the reduced closure element transitions from the natural, planar configuration to a tubular configuration.
FIG. 6F illustrates a bottom view of the closure element ofFIGS. 6C-6D upon completing the transition from the natural, planar configuration to a substantially tubular configuration.
FIG. 6G illustrates a side view of the closure element ofFIG. 6F.
FIG. 6H illustrates a side view of the closure element with the tines at various angles.
FIGS. 7A-7B illustrate a collapsible tubular closure element.
FIGS. 8A-8B illustrate a self-rolling closure element.
FIGS. 9A-9B illustrate a reverse closure element.
FIGS. 10A-10B illustrate a clam closure element.
FIG. 11 illustrates an endoscope having medial device components for repairing a fistula.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTSGenerally, the present invention includes a medical device for repairing a fistula. The fistula can be any type of fistula that provides an abnormal channel from one body part to another body part (e.g., organ to organ, organ to vessel, and/or vessel to vessel). The medical device of the present invention can be configured to repair any type of fistula at any location within the body of a subject. Examples of fistulas that can be repaired with the present invention include anorectal fistulas, enteroenteral fistulas, enterocutaneous fistulas, vesicovaginal fistulas, arteriovenous fistulas, perilymph fistulas, rectovaginal fistulas, ureterocolon fistulas, vesicointestinal, bronchoesophageal, cervical, colocutaneous, abdominal, biliary, blind, congenital, genitourinary, orofacial, uretocutaneous, uretovaginal, vessical, duodenal, and the like.
The present invention can include a medical device having an elongate shaft with a distal garage housing a closure element that is configured for being delivered into tissue surrounding a fistula in order to promote fistula repair. Additionally, the medical device can have sufficient distal flexibility and/or controllability so as to be capable of traversing through a natural opening that communicates with a body lumen to a fistula formed with another body lumen. The closure element can be applied to the tissue on the outer edge or internal surface or any other location related to the fistula in order to repair the fistula. The shaft and/or garage that retains the closure element during placement proximal to the fistula can have increased flexibility at the distal end in order to enhance the ability to traverse around bends or junctions in body lumens for placement adjacent to or within a fistula. The increased flexibility can also enhance the ability to point the tip (e.g., garage) toward or into the fistula when at an angle with respect to the orientation of the body lumen.
I. Fistula RepairThe medical device of the present invention can be configured to repair a fistula by applying a closure element to tissue adjacent to or within a fistula. There are various strategies that can be employed in order to repair a fistula, which includes various areas of tissue that are proximal or associated with the fistula in which the closure element can be applied. This can include applying a closure element to the tissue surrounding a fistula, to the tissue within a fistula canal, to the tissue both surrounding the fistula and the tissue within the fistula canal, to tissue on an opposite side of the fistula, to tissue on both sides of the fistula canal, to tissue adjacent to both openings of the fistula, and the like. Accordingly, the medical device of the present invention can be configured such that the closure element applier can deliver an embodiment of closure element to repair the fistula as described in connection toFIGS. 1A-1I.
FIG. 1A is a general schematic representation of abody portion10 having afirst body lumen12 and asecond body lumen14 separated by afirst tissue portion16 and asecond tissue portion18 with afistula20 disposed therebetween. Thefistula20 has afirst opening22 defined by afirst opening wall22a(e.g., tissue) that communicates with thefirst body lumen12 and asecond opening24 defined by asecond opening wall24a(e.g., tissue) that communicates with thesecond body lumen14. Afistula conduit26 defined by afistula conduit wall26a(e.g., abnormal tear surface) can extend between thefirst opening22 andsecond opening24 of thefistula20. Thebody lumens12,14 can also be body cavities or organs, which are referred to herein generally as body lumens.
Amedical device30 having aflexible potion32 andgarage35 retaining a closure element34 (FIG. 1B) is shown to be disposed in thefirst body lumen12 and thegarage35 is aligned along the longitudinal direction of the first body lumen. As shown, theflexible portion32 is not bent or deflected toward thefistula20.
FIGS. 1B-1I are schematic representations of themedical device30 being inserted into thefirst body lumen12, and positioned at thecorresponding opening22 of thefistula20. As shown inFIG. 1B, themedical device30 can be inserted into thefirst body lumen12 via a natural body opening that naturally communicates with one of the body lumens. A natural body opening can be the mouth, nostril, urethra, vagina, anus, and the like. Also, themedical device30 can be inserted through the fistula itself. As such, themedical device30 can be inserted into and moved through the natural body opening until theflexible portion32 andgarage35 passes through thebody lumen12 and reaches thefistula20. Such positioning can be achieved with the distal end of themedical device30 having aflexible portion32. Theflexible portion32 is flexed by controllingbending elements31a,31bthat are coupled to acontraction point33aor anextension point33b,or vice versa depending on orientation. For example, the bendingelement31a is contracted so as to pull thecontraction point33ais a proximal direction, and the bendingelement31bis extended so as to push theextension point33bin a distal direction. The simultaneous movement of the bendingelements31a,31bcan selectively bend theflexible portion32 to point the garage in a desired direction, such as toward thefistula20. Thegarage35 of themedical device30 can then be positioned adjacent to thefistula20 such that theclosure element34 can be applied to the tissue of the repair location28 adjacent to or defining thefistula20 in order to repair thefistula20.
Delivery of themedical device30 through a natural body lumen or organ to the site of thefistula20 can be advantageous in that many of thebody lumens12,14 susceptible to developing afistula20 have a diameter of sufficient size to allow for amedical device30, such as a catheter or endoscope, to be passed therethrough. This also allows for themedical device30 to have a size that is large enough to provide agarage35 for maintaining deployment components (e.g., bendingelements31a,31b,contraction point33a,extension point33b,etc.) that are configured to be manipulated and controlled by a user so as to control the deployment of thegarage35 of themedical device30 to thefistula20. The deployment components can be any component that operates so as to allow theflexible portion32 of the medical device so be flexed or bent so as to be passed around tight bends, into select lumen, or bend to be at any angle relative to the longitudinal direction of the lumen.
For example, the deployment components can be manipulated so that the position and orientation of thegarage35 can be passed into afistula20 having a substantially longitudinal axis that is at an angle (e.g., alpha) with respect to the longitudinal axis of the body lumen. This can include manipulating theflexible portion32 of themedical device30 to be at an angle (e.g., alpha) of about 45 degrees, 90 degrees, 135 degrees, 180 degrees, and any angle therebetween. For example, the route of deployment may result in the tip of themedical device30 needing to be turned in 180 degrees in order to enter an opening of thefistula20, and the deployment components can cause the tip to be turned at 180 degrees for deployment of theclosure element34.
In one embodiment, theflexible portion32 can be sufficient flexibility so as to be capable of being bent at an angle of about 45 degrees, about 90 degrees, about 135 degrees, about 180 degrees, and any angle therebetween. This can be achieved by utilizing materials for the various components that are included in thegarage35 and for thegarage35 itself. Many medical-grade polymers can be configured to be elastic enough for such flexibility. Theflexible portion32 or entire distal end of themedical device30 including thegarage35 can be configured to have sufficient flexibility to bend as described herein. Optionally, themedical device30 and the components thereof can have shape memory so as to automatically return to the original orientation, such as substantially straight or curved. However, theflexible portion32 can also be configured to be malleable so as to retain the orientation once obtained. Such malleability can be used to bend the distal end of themedical device30 in one direction and retain that direction until the distal end is bent in a different direction. The bending can be achieved by pushing one of the bendingelements31aor31band pulling the other so that thecontraction point33acontracts one side of themedical device30 and theextension point33bextends the other side of the medical device, which functionally bends the medical device in a desired direction.
FIG. 1C shows themedical device30 after theflexible portion32 has been bent so as to point thegarage35 toward thefistula20. After thegarage35 is placed proximal to thefistula20, alocator assembly200 can be utilized to locate thefistula20. Thelocator assembly200 can include alocator220 at thedistal end210. Thelocator220 may be retained within thegarage35 during placement proximal to thefistula20. As shown, thegarage35 can also include features of acarrier assembly300, which can include asupport member340, acarrier member310, apusher member320, and acover member330. Thecarrier member310 can include theclosure element34 in aspace370 associated with thecarrier member310,pusher member320, and covermember330. Thelocator220 can be extended into thefistula20 by being distally pushed so that thedistal end210 is within thefistula20.
After being placed within, adjacent or proximal to thefistula20, thelocator220 can be expanded by radial or laterally expandinglocator wings231 as shown inFIG. 1D. The locator wings321 can be expanded to a sufficient length for contacting tissue of thefistula20, which can include the tissue of thebody lumen14. The contact of the locator wings321 with thefistula20 can be used to identify when thefistula20 is located. Also, proximally pulling thelocator220 against thefistula20 can also be useful. Additionally, radiopaque materials on thelocator220 and/orlocator wings231 can be helpful in locating thefistula20.
Additionally,FIG. 1D shows thecarrier assembly300 being extended from thegarage35. However, the functionality of themedical device30 can be retained when only selected components, such as components of thelocator assembly200 andcarrier assembly300, are extended from thegarage35.
FIG. 1E shows the operation of thecarrier assembly300 in deploying theclosure element34 to repair thefistula20. As shown in cross-sectional view, thepusher member320 has pushed theclosure element34 over thecarrier member310 and out of thecover member330 so as to penetrate the tissue of thefistula20. Thecarrier member310 is shown to have a radially expanding cross-section at the distal end, which allows for theclosure element34 to be radially expanded during deployment into the tissue. Such radial expansion of theclosure element34 allows for the tines36 (e.g., tissue grabbing members) to enter the tissue of thefistula20 at an angle that allows for more tissue to be grabbed.
During the deployment of theclosure element34 into the tissue of thefistula20, thelocator wings231 can be retracted as shown by the arrows. The retraction of thelocator wings231 allows for thelocator220 to be withdrawn from thefistula20 as theclosure element34 is repairing thefistula20. Accordingly, many different functional actions can be occurring simultaneously or substantially simultaneously during the process of repairing thefistula20 and/or after deployment of theclosure element34.
FIG. 1F shows theclosure element34 retracting to a closed orientation that repairs thefistula20. The closed orientation of theclosure element34 can be achieved by thetines36 being drawn, radially together. This allows thetines36 to pull tissue together to repair thefistula20.
Also,FIG. 1F shows thelocator220 being fully retracted from thefistula20. It can be beneficial to retract thelocator220 from thefistula20 during deployment of theclosure element34 so that thelocator220 or its components are not stuck or otherwise trapped within the repairedfistula20. Accordingly, the timing ofclosure element34 deployment and locator retraction can be correlated to achieve maximum benefit of having sufficient fistula location identification during the deployment of the closure element, but to also have selected retraction of thelocator220 to avoid any complications that may arise if thelocator220 was trapped by theclosure element34.
FIG. 1G is a schematic representation of an embodiment of a procedure to repair afistula20 with amedical device30 that deploys ahelical closure element34. As described inFIG. 1B, the distal end of themedical device30 is positioned at theopening22 of thelumen12 and theflexible portion32 is bent so as to be directed toward thefistula20. Theflexible portion32 is flexed by controllingbending elements31a,31bthat are coupled to acontraction point33aor anextension point33b.For example, the bendingelement31ais contracted so as to pull thecontraction point33ain a proximal direction, and the flexingelement31bis extended so as to push theextension point33bin a distal direction. The simultaneous movement of the bendingelements31a,31bcan selectively bend theflexible portion32. Thehelical closure element34ais deployed from thegarage35 toward thefistula20 with the helical turn being of a diameter larger than or about the size of theconduit26 so that thetine36ais capable of spiraling through the tissue of theconduit wall26auntil reaching a select point, such as theopposite opening24. Thehelical closure element34 can then be pulled taut so as to close theconduit26. Alternatively, the winding of thehelical closure element34 can pull the tissue of thefistula20 together.
FIG. 1H is a schematic representation of an embodiment of a procedure to repair afistula20 with amedical device30 that deploys a conical, helical closure element34d.The conical,helical closure element34 has a shape similar to that of a tornado so as to have a larger diameter distal end adjacent to thetine36 compared to the diameter adjacent to thegarage35. Theflexible portion32 is flexed by controllingbending elements31a,31bthat are coupled to acontraction point33aor anextension point33b.For example, the bendingelement31ais contracted so as to pull thecontraction point33ais a proximal direction, and the bendingelement31bis extended so as to push theextension point33bin a distal direction. The simultaneous movement of the bendingelements31a,31bcan selectively bend theflexible portion32 so as to point into thefistula20. The conical,helical closure element34bis deployed from thegarage35 toward the tissue of thefistula20 with the distal helical turn being of a diameter at least or larger than theconduit26 so that thetine36bis capable of spiraling through the tissue of theconduit wall26auntil reaching a select point, such as theopposite opening24. As the conical,helical closure element34bis deployed, the conical shape pulls theconduit26 closed from thefirst opening22 to thesecond opening24. This preferentially closes one opening (e.g.,22) compared to the opposite opening (e.g.,24).
Themedical device30 can deploy the closure element34 (shown retained within the medical device) at a suitable repair location at thefirst opening22, second opening,24, or any location within thefistula conduit26. Depending on the location of thefistula20 and the organs and/or vessels affected by thefistula20 it may be advantageous in some circumstances to close thefistula20 at one of theopenings22,24. However, a closure element that can be deployed within thefistula conduit26 can be advantageous in other circumstances.
FIG. 1I is an illustration of an embodiment of aclosure element34 closing afistula20. As shown, the fistula ofFIG. 1A has been closed by applying a closure element as inFIG. 1B to thefirst opening wall22aof thefirst opening22. By thefirst opening22 being sealed, thefistula conduit26 can drawn closed. Thesecond opening24 can thereby also be closed.
In on embodiment, the medical device can be delivered by a methodology that utilizes a catheter to deliver the medical device. In such a configuration, the garage of the medical device can be directed through the lumen of a catheter. This can include the medical device being traversed through an internal lumen of the catheter so that the distal end and garage can be passed therethrough and be directed toward the fistula. The catheter can be delivered to the fistula in any manner of catheter delivery, such as being passed over a guidewire (not shown). Thus, the flexibility of the medical device is sufficient to be passed through a catheter to the fistula.
Optionally, the medical device, including the garage and other portions of the medical device, can be substantially devoid of deployment components, such as the bending members and the like. As such, the flexibility is suitable for traversing the body lumen to the site of the fistula by being passed through a catheter lumen.
In on embodiment, the medical device can be configured to include components of an endoscope so that the medical device can be delivered to the fistula in a manner that endoscopes are delivered to sites within a body. In such a configuration, the endoscope can be delivered to the fistula, and the garage of the medical device can be directed through the lumen of the endoscope to the fistula. This can include the medical device being traversed through an internal lumen of the endoscope so that the distal end and garage can be passed therethrough. The endoscope can be delivered to the fistula an any manner of endoscope delivery, such as utilizing an endoscope light and camera for maneuvering the endospcope through body lumen to the fistula. The endoscope can also include standard endoscope components that enable the endoscope to traverse a body lumen so as to be deployed at a fistula. As such, the flexibility of the medical device is sufficient to be passed through an endoscope to the fistula. The medical device, including the garage and other portions of the medical device, can be substantially devoid of deployment components (e.g., bending members) such that the endoscope provides a route, and the medical device is flexible enough to traverse the route. Optionally, the medical device is integrated with an endoscope such that the garage having the closure element is delivered to the fistula while the endoscope is being delivered to the fistula.
In one embodiment, the medical device can be inserted into one of the body lumens or into the fistula conduit via an incision made through the skin and tissue proximate to the fistula. Accordingly, an incision can be made in the skin (not shown) and tissue adjacent to the fistula. This can allow for percutaneous delivery of the garage of the medical device to the fistula. Medical devices commonly configured to be traversed through an incision for percutaneous delivery, such as catheters, can be configured without the flexibility and/or maneuverability of other medical devices as described herein because the incision can provide a substantially straight conduit for passing the medical device to the repair site of the fistula without having to traverse any tight bends or other similar features. Also, it may be desirable for the incision to be substantially smaller than a normal opening so as to impart less trauma to the subject. As such, the medical device can have dimensions similar to catheters that are deployed percutaneously.
II. Closure Element ApplierThe closure element applier can be configured to receive and retain the closure element (i.e., fistula closure element) such that the closure element is disposed substantially within the closure element applier. The closure element applier is configured to engage the tissue within and/or adjacent to one of the openings of the fistula, and to position and deliver the closure element into tissue to draw the tissue together in order to repair the fistula. When properly positioned, the closure element applier can be activated to distally deploy the closure element. During deployment of the closure element, the closure element applier can be configured to substantially uniformly or asymmetrically expand the closure element beyond a natural cross-section of the closure element such that the tines, barbs, or the like engage a significant amount of the tissue for repairing the fistula. After engaging the tissue, the closure element can then return to substantially the natural cross-section area and shape of the memory material. Thereby, the engaged tissue is drawn substantially closed and/or sealed, such that the fistula is repaired.
FIGS. 2A-2D illustrate a closure elementapplier apparatus100 in accordance with the present invention. Theapparatus100 can be configured to receive and retain a closure element (not shown; discussed below) such that the closure element is disposed substantially within theshaft102 of the closure elementapplier apparatus100. Theapparatus100 can be provided as one or more integrated components and/or discrete components. As shown inFIG. 2A, theapparatus100 can include a locator (or obturator)assembly200 and acarrier assembly300. For purposes of illustration, thelocator assembly200 and thecarrier assembly300 are shown inFIG. 2A as including substantially separate assemblies. As desired, however, thelocator assembly200 and thecarrier assembly300 each can be provided, in whole or in part, as one or more integrated assemblies. Information related to closure element appliers, locator assemblies, carrier assemblies, components thereof, mechanics thereof, and operation thereof can be obtained from U.S. Pat. No. 6,197,042 and co-pending applications and Ser. Nos. 09/610,128, 09/732,835, 09/866,551, 10/006,400, 10/081,723, 10/356,214, 10/638,115, 11/048,503, 11/396,731, 11/744,089, 12/113,092, 60/946,042, and 60/946,030, the disclosures of which are expressly incorporated herein by reference.
Being configured to extend into a fistula opening, thelocator assembly200 can selectably contact tissue within the fistula canal or adjacent to the fistula. Whereby, thelocator assembly200 can be configured to draw theclosure element applier100 taut and maintain the proper position of theclosure element applier100 in relation to the fistula. Thelocator assembly200 can include a flexibletubular body210, wherein the flexibility allows for delivery through a body lumen and placement at the fistula. As illustrated inFIG. 2A, the locatortubular body210 has aproximal end region210a and adistal end region210band includes apredetermined length218aand a predeterminedouter cross-section218b,both of which can be of any suitable dimension. Thedistal end region210bof thelocator assembly200 can include a substantially rounded, soft, and/or flexible distal end or tip220 (e.g., locator) to facilitate atraumatic advancement and/or retraction of the flexibledistal end region210bthrough the body lumen and to the fistula. As desired, thelocator220 can be more flexible to allow for being placed at or within the fistula, and can include deployment components (not shown) that bend and flexdistal end region210 so as to point thelocator220 toward the fistula.
Thelocator220 of thelocator assembly200 further can be selectably controllable between an unexpanded state (FIG. 2B) and an expanded state (FIGS. 2A and 2C). In the unexpanded state, thelocator220 has an unexpanded size; whereas, thelocator220 in the expanded state has an expanded size, which is greater than the unexpanded size. Thelocator220 can be configured to expand from the unexpanded size to the expanded size and/or to contract from the expanded size to the unexpanded size, and the expansion and contraction of the locator can be substantially uniform about longitudinal axis of thelocator assembly200. For example, one or more expansion elements230 (i.e., locator wings230) can be provided on thelocator220, and can be configured to expand substantially transversely with respect to alongitudinal axis216 of thelocator assembly200. Theexpansion elements230 can be substantially equally distributed about anouter periphery212 of thelocator220. Optionally, theexpansion elements230 may include radiopaque markers (not shown) or may be wholly or partially formed from a radiopaque material to facilitate observation of theexpansion elements230 and/or thelocator220 using fluoroscopy or other imaging systems.
At least one of theexpansion elements230 can include a substantiallyflexible member231 with a substantially fixedend region232, anintermediate region233, and amovable end region234 as shown inFIGS. 2B-2C. For each substantiallyflexible member231, thefixed end region232 can be fixedly coupled with thelocator220; whereas, themovable end region234 can be movably coupled with thelocator220, and configured to be axially movable relative to thefixed end region232. When eachmovable end region234 can be axially moved toward the relevantfixed end region232, theintermediate regions233 buckle and/or expand transversely outwardly, thereby transitioning thelocator220 of thelocator assembly200 from the unexpanded state to the expanded state. In contrast, thelocator220 transitions from the expanded state to the unexpanded state as each of themovable end regions234 are axially moved away from the relevantfixed end region232. Although theexpansion elements230 are shown as including theflexible members231 inFIGS. 2B-2C for purposes of illustration, it is understood that theexpansion elements230 can include any type of expansion elements and are not limited to the illustrated embodiments. It is further contemplated that theexpansion elements230 may further include geometric features that allow/enhance the ability of the expansion elements to bend or fold from a retracted position to an expanded position. Theexpansion elements230 may be constructed of a material such as steel, spring steel, plastics or composites. In one embodiment, the expansion elements are constructed of nitinol.
Referring now toFIG. 2D, thelocator assembly200 may further include alocator control system240 associated with the locator assembly. As shown inFIG. 2D, thelocator control system240 can be associated with theproximal end region210aof thelocator assembly200 and can be configured to selectively control thedistal end region210b(e.g., flexibility, straightness, bends, positioning, and the like) andlocator220 of thelocator assembly200 between the unexpanded and expanded states. Thelocator control system240 can selectively control thedistal end region210bto be longitudinally oriented or bent away to an angle up to 45, 90, 120 and/or 90 degrees. Thelocator control system240 can also control thelocator220 and thelocator wings230 between the unexpanded and expanded states, such as by being activated by a switching system (not shown). For example, at least onecontrol member250, such as a rod, wire, or other elongate member, can be moveably disposed within a lumen (not shown) formed by thetubular body210 and extending substantially between theproximal end region210aand thedistal end region210b.Thecontrol member250 has a proximal end region250athat is coupled with thelocator control system240, which can be via a control block260 (shown inFIG. 4D), and a distal end region (not shown) that is coupled with thedistal end region210bandlocator220 of thelocator assembly200, theexpansion elements230, and/or themovable end regions234 of the substantiallyflexible members231.
Additionally, thelocator control system240 can selectively transition thedistal end region210bfrom being straight to being bent, curved, or the like, and change theexpansion elements230 and/or the substantiallyflexible members231 between the unexpanded and expanded states by moving thecontrol member250 axially relative to thetubular body210. However, thecontrol member250 can be configured such that any articulation by other mechanical components can control the bending of thedistal end region210bas well as the expansion and contraction of thelocator wings230.
Thelocator control system240 further includes a locator release system490 (FIG. 4D) for maintaining the unexpanded state and/or the expanded state of thelocator220, theexpansion elements230, and/or the substantiallyflexible members231. Thelocator release system490 can be configured to maintain the expanded state of thelocator220, and can include any type of locking system and can be engaged, for instance, by activating a switching system or other means of activation. For example, once the substantiallyflexible members231 have entered the expanded state, thelocator release system490 can secure thecontrol member250 to prevent axial movement relative to thetubular body210, thereby maintaining the substantiallyflexible members231 in the expanded state.
In the manner described in more detail below, thelocator control system240 also can be configured to disengage thelocator release system490, such that thelocator220, theexpansion elements230, and/or the substantiallyflexible members231 can transition between the expanded and unexpanded states. Thelocator release system490 can be disengaged, for example, by activating a mechanism (e.g., an emergency release system) (not shown). As desired, thelocator control system240 may further include a biasing system (not shown), such as one or more springs or other resilient members, to bias thelocator220, theexpansion elements230, and/or the substantiallyflexible members231 to enter and/or maintain the unexpanded state when thelocator release system490 is disengaged.
Returning toFIG. 2A, thecarrier assembly300 can be coupled with, and slidable relative to, thelocator assembly200. Thecarrier assembly300 is configured to receive and retain the closure element (not shown), which can be disposed substantially within thecarrier assembly300. Turning now toFIGS. 3A-3D, thecarrier assembly300 can include atube set305, including acarrier member310, apusher member320, asupport member340, and acover member330. Thecarrier member310, thepusher member320, thesupport tube340, and thecover member330 can be provided as a plurality of nested, telescoping members with a commonlongitudinal axis350 as illustrated inFIG. 3A. Thecarrier member310 can be configured to receive and support the closure element (not shown). While being disposed on thecarrier member310, the closure element can be deformed from the natural or memory set shape and configuration to a retention or delivery configuration, which retention or delivery configuration can be different in different embodiments as described herein. Being disposed substantially about, and supported by, anouter periphery312bof thecarrier member310, the closure element can be substantially in axial alignment with thecarrier member310 with thetines520 pointed an a variety of directions ranging from being pointed substantially distally, at about 45 degrees, about 90 degrees, about 120 degrees, to about 180 degrees or substantially proximally.
The position of the closure element with regard to the tube set can vary depending on various factors, such as the flexibility of the tube set or the distal end of the tube set. As such, the closure element can be located in a storage configuration (e.g., tubular) at a proximal position, distal position, or any position therebetween.
As shown inFIG. 3A, thecarrier assembly300 includes at least one bending member301 (e.g.,301aand301b). Each bending member301 is shown to be disposed internally to thesupport member340; however, the bending member301 could be placed between thesupport member340 and thecarrier member310, between thecarrier member310 and thepusher member320, between thepusher member330 and thecover member330, or even external to thecover member330 or internal to thesupport member340 as shown by the dashed lines. The bendingmembers301a,bcan bend thecarrier assembly300 by one bendingmember301abeing pushed while the other bendingmember301bis held or pulled, or vice versa. Alternatively, the bendingmember301acan be pulled while the other bendingmember301bis pushed or held. Optionally, each bendingmember301a,bcan be coupled to a member of thecarrier assembly300 to facilitate bending. As shown, thefirst bending member301ais coupled to afirst bending point302aof thesupport member340 and the second bending member is coupled to asecond bending point302b.For example, thefirst bending member301ais contracted so as to pull thebending point302ain a proximal direction, and thesecond bending member301bis extended so as to push thesecond bending point302bin a distal direction. The simultaneous movement of the bendingmember301a,bcan selectively bend thecarrier assembly300 so as to point into the fistula.
FIG. 3B illustrates an embodiment of acarrier member310. Thecarrier member310 can be formed as a substantially rigid, semi-rigid, or flexible tubular member; however, it can be advantageous for thedistal end region310bof thecarrier member310 to have sufficient flexibility to be bent and placed at or within a fistula. For example, thecarrier member310 can be longitudinally stiffer and radially or laterally flexible. Additionally, thecarrier member310 can have aproximal end region310aand apredetermined length318aand apredetermined cross-section318b,both of which can be of any suitable dimension. Thecarrier member310 also can have anexternal surface312band aninternal surface312athat defines alumen314 that extends substantially between theproximal end region310aand thedistal end region310band that is configured to slidably receive at least a portion of thetubular body210 of thelocator assembly200. Although thecross-section318bof thecarrier member310 generally is substantially uniform, thedistal end region310bof thecarrier member310 can have a cross-section that increases distally, as illustrated inFIGS. 3A-3B, for substantially uniformly expanding the closure element during deployment into tissue of the fistula. To deploy the closure element without expansion, thedistal end region310bcan be formed with a cross-section (not shown) that is substantially uniform, which can be of similar dimensions of theproximal end region310a.Although shown and described as having the cross-section that increases distally for expanding the closure element, it will be understood that thedistal end region310bof thecarrier member310 can be provided with the substantially-uniform cross-section.
FIG. 3C illustrates an embodiment of apusher member320 that is configured to distally deploy the closure element for repairing a fistula. Thepusher member320 has aproximal end region320aand adistal end region320b,and includes apredetermined length328aand apredetermined cross-section328b,both of which can be of any suitable dimension. Also, thepusher member320 can include anexternal surface322band aninternal surface322athat defines alumen324 for slidably receiving thecarrier member310 such that thedistal end region320bof thepusher member320 is offset proximally from thedistal end region310bof thecarrier member310 as shown inFIG. 3A. As desired, thepredetermined length328aof thepusher member320 can be shorter than, greater than, or substantially equal to thepredetermined length318aof thecarrier member310. Thepredetermined length328aof thepusher member320, however, can be less than thepredetermined length318aof thecarrier member310 such that thecarrier member310 and thepusher member320 at least partially define aspace360 distal to thedistal end region320bof thepusher member320 and along theperiphery312bof thecarrier member310. Thespace360 is also referred to as thegarage360 in which the closure element is retained within theclosure element applier100.
Thepusher member320 can be a substantially rigid, semi-rigid, or flexible tubular member; however, thedistal end region320bcan be flexible as described herein so that the tip220 (i.e., locator220) can be placed at or within the fistula. Thecross-section328bof thepusher member320 can be substantially uniform, and thedistal end region320bof thepusher member320 can include one or morelongitudinal extensions325, which extend distally from thepusher member320 and along theperiphery312bof thecarrier member310 as shown inFIG. 3C. Thelongitudinal extensions325 can be biased such that thelongitudinal extensions325 extend generally in parallel with commonlongitudinal axis350 of thecarrier assembly300. Thelongitudinal extensions325 are sufficiently flexible to bend for placement of thetip220 with respect to the fistula and to expand radially, and yet sufficiently rigid to inhibit buckling, as thedistal end region320bis directed distally along thecarrier member310 and engage the distally-increasing cross-section of thedistal end region310bof thecarrier member310 to deploy the closure element. For example, thepusher member320 andlongitudinal extensions325 can be longitudinally stiffer and radially or laterally flexible.
FIG. 3D illustrates an embodiment of acover member330 configured to retain the closure element substantially within thecarrier assembly300 prior to deployment. Being coupled with, and slidable relative to, thepusher member320, thecover member330 has aproximal end region330aand adistal end region330band includes apredetermined length338aand apredetermined cross-section338b,both of which can be of any suitable dimension. Thecover member330 can also be formed as a substantially rigid, semi-rigid, or flexible tubular member, and thedistal end region330bcan be flexible for placement of thetip220 with respect to a fistula as described herein. For example, thecover member330 can be longitudinally stiffer and radially or laterally flexible. Additionally, thecover member330 can have aninner periphery332athat defines alumen334, and anouter periphery332b.Thelumen334 can extend substantially between the proximal anddistal end regions330a,330bof thecover member330 and can be configured to slidably receive at least a portion of thepusher member320. When thecover member330 is properly positioned within thecarrier assembly300, thedistal end region330bcan be configured to extend over thespace360, thereby defining anannular cavity370 for receiving and retaining the closure element. Theannular cavity370 along with thespace360 can be referred to as the garage because they cooperate to retain the closure element within thecarrier assembly300.
Thecross-section338bof thecover member330 can be substantially uniform, and thedistal end region330bof thecover member330 can include one or morelongitudinal extensions335, which extends distally from thecover member330 and along anouter periphery322bof thepusher member320. Although thelongitudinal extensions335 can extend generally in parallel with commonlongitudinal axis350, thelongitudinal extensions335 can be biased such that the plurality oflongitudinal extensions335 extend substantially radially inwardly as illustrated inFIGS. 3A and 3D. Thereby, thelongitudinal extensions335 can at least partially close thelumen334 substantially adjacent to thedistal end region330bof thecover member330. To permit the closure element to be deployed from theannular cavity370, thelongitudinal extensions335 can be sufficiently flexible to expand radially to permit thedistal end region310bof thecarrier member310 to move distally past thecover member330 to open theannular cavity370 such that thedistal end region330bno longer extends over thespace360. This effectively opens the garage so that the closure element can be deployed into the tissue of the fistula.
When thecarrier assembly300 is assembled as the plurality of nested, telescoping members as shown inFIG. 3A, thecarrier member310 can be at least partially disposed within, and slidable relative to, thelumen324 of thepusher member320. Thepusher member320, in turn, can be at least partially disposed within, and slidable relative to, thelumen334 of thecover member330. To couple thecarrier assembly300 with thelocator assembly200, thetubular body210 of thelocator assembly200 can be at least partially disposed within, and slidable relative to, thelumen314 of thecarrier member310. The corresponding positioning of thelocator assembly200 andcarrier assembly300 is shown inFIG. 2A. The longitudinal axis of thelocator assembly200 can be substantially in axial alignment with the commonlongitudinal axis350 of thecarrier member310, thepusher member320, thecover member330, and thesupport tube340.
It will be appreciated that the tube set305 can optionally include asupport member340 as shown inFIGS. 3A and 3E. Thecarrier assembly300 can advantageously include thesupport member340, for example, if thetubular body210 of thelocator assembly200 is not sufficiently rigid or under other circumstances in which support for thetubular body210 might be desirable. It also will be appreciated that thesupport member340 also can be configured to inhibit the plurality oflongitudinal extensions335, which extend from thedistal end region330bof thecover member330, from expanding prematurely prior to the closure element being deployed. Thesupport member340 is configured to slidably receive thetubular body210 of thelocator assembly200 and to provide radial support for thedistal end region210bof thetubular body210 when thelocator assembly200 is coupled with thecarrier assembly300.
Thesupport member340 can be formed as a substantially rigid, semi-rigid, or flexible tubular member having aproximal end region340aand adistal end region340b.Thedistal end region340bcan be sufficiently flexible so as to allow for thetip220 to be placed at or within a fistula. For example, thesupport member340 can be longitudinally stiffer and radially or laterally flexible. Thesupport member340 includes anouter surface342band aninner surface342athat defines alumen344 that extends substantially between theproximal end region340aand thedistal end region340b.The lumen is configured to slidably receive and support at least a portion of thetubular body210 of thelocator assembly200. Thesupport member340, in turn, can be at least partially slidably disposed within thelumen314 of thecarrier member310 such that thetubular body210 of thelocator assembly200 may be coupled with, and slidable relative to, thecarrier member310 in the manner described herein. Thesupport member340 can have apredetermined length348aand a predetermined cross-section348b,both of which can be of any suitable dimension, and the cross-section348bcan be substantially uniform. Although shown and described as being substantially separate for purposes of illustration, it will be appreciated that thecarrier member310, thepusher member320, thecover member330, and/or thesupport member340 can be provided, in whole or in part, as one or more integrated assemblies.
FIGS. 4A-4D illustrates an embodiment of amedical device100 including ahousing380 that stores components for actuating the deployment of the closure element (not shown). Thehousing380 can be formed as an elongate member with alongitudinal axis386. Additionally, thehousing380 can have anouter surface382, and includes aproximal end region380aand adistal end region380b.While not specifically shown, when themedical device100 is properly assembled, thetubular body210 of thelocator assembly200 can be at least partially disposed within the tube set305 of thecarrier assembly300. Thedistal end region210bof thetubular body210 either extends or is extendable beyond thedistal end regions310b,320b,330b,and/or340b(FIG. 4C) of the tube set305. Further, theproximal end region210aof thetubular body210 and theproximal end regions310a,320a,330a,and/or340a(FIGS. 3A-3E) of the tube set305 are at least partially disposed within, and slidable relative to, thehousing380. By being configured to slidably retain the respectiveproximal end regions210a,310a,320a,330a,and340a,thehousing380 supports the tube set305 and can have one ormore handles390 to facilitate use of themedical device100. Thehandles390 extend substantially radially from theouter surface382 of thehousing380 and can be provided in any shape, size, orientation, and manner known in the art.
Thelocator control system240 and at least one control member250 (both shown inFIG. 2D) of thelocator assembly200, and aswitching system450 of the triggeringsystem400 can be accessible external to thehousing380 as shown inFIGS. 4A-4D. The tube set305 can be functionally coupled include aswitching system450 so as to operate and control the members of the tube set305 for deployment of the closure element.
FIGS. 4A-4C illustrate a pair of bendinglevers304a,bthat protrude through thehousing380. The bending levers304a,bare coupled to the bendingmembers301a,b.The bendingmembers301a,bcan be coupled to any member of the tube set305, and are shown to be coupled to thesupport member340. The bendingmembers301a,bcan be coupled to a single point or at any points along the support member. In operation, axially sliding one or both of the bending levers304a,bcauses the bendingmembers301a,bto also slide axially so as to bend thecarrier assembly300 by compressing or extension of one side of thecarrier assembly300 such as through the compression of thesupport member340. The bending function is accomplished by one bendingmember301abeing pushed while the other bendingmember301bis held or pulled, or vice versa, by sliding one of the bending levers304a,brelative to the other bending lever. Alternatively, the bendingmember301acan be pulled by pulling the bendinglever304awhile the other bendingmember301bis pushed or held by controlling the bendinglever304b.As shown, thefirst bending member301ais coupled to afirst bending lever304a,and the second bending member is coupled to asecond bending lever304b.
As shown inFIG. 5D, when thefirst bending member301ais pulled in a proximal direction by proximally pulling thefirst bending lever304ain a proximal direction, and/or thesecond bending member301bis pushed in a distal direction by distally pushing thesecond bending lever304bin a distal direction, thecarrier assembly300 is bent in a first direction. Accordingly, a bendingportion306 of thecarrier assembly300 is shown to bend so that thelocator220 points toward the fistula.
As shown inFIG. 5E, when thefirst bending member301ais pushed in a distal direction by distally sliding thefirst bending lever304ain a distal direction, and/or thesecond bending member301bis pulled in a proximal direction by proximally sliding thesecond bending lever304bin a proximal direction, thecarrier assembly300 is bent in a second direction. Accordingly, a bendingportion306 of thecarrier assembly300 is shown to bend so that thelocator220 points toward the fistula.
The simultaneous relative movement of the bending levers304a,bcan selectively bend thecarrier assembly300 so as to point into the fistula. Each bending member301 is shown to be disposed internally to thesupport member340; however, the bending member301 could be placed between thesupport member340 and thecarrier member310, between thecarrier member310 and thepusher member320, between thepusher member330 and thecover member330, or even external to thecover member330 or internal to thesupport member340 as shown in the dashed lines ofFIG. 3A.
Alternatively, the bending members301 can be slid distally and/or proximally by being attached to some other actuating mechanism. Accordingly, the bending levers304 (e.g., axially sliding levers) can be configured into a different actuating mechanism or can be coupled to a different actuating mechanism. For example, the bending members301 and/or the bending levers304 can be coupled to a rotating dial, screw and thread mechanism, worm gear, laterally-moving lever, or the like to facilitate proximal or distal movements of the bending members301 that causes lateral and/or radial bending of thecarrier assembly300 so that thelocator220 and the closure element (not shown) is directed toward a fistula.
Additionally, while only two bending members301 and bending levers304 are shown in the figures, any number of bending members, bending levers, or other actuating components that can bend thecarrier assembly300 can be included. This can include 1, 2, 3, 4, 5, 6, or more bending members, bending levers, or other components that facilitate bending by axial motion. Also, the bending members301, bending levers304, or other axially moving members can be present in pairs disposed opposite from each other as illustrated. Bending member pairs can be disposed oppositely so that the relative movement bends the carrier assembly in a first direction or in the opposite second direction.
Referring back toFIGS. 4A-4D, a triggeringsystem400 can be disposed substantially within thehousing380. The triggeringsystem400 can be configured to control the relative axial movement and/or positioning of the respectivedistal end regions310b,320b,330b,and340bof the tube set305 and/or thedistal end region210band/or tip220 of thelocator assembly200. By being coupled with theproximal end regions210a,310a,320a,330a,and/or340a,the triggeringsystem400 can control the relative axial movement of thedistal end regions210b,310b,320b,330b,and/or340bin any manner, such as by being activated by theswitching system450. Actuation of the triggeringsystem400 and switchingsystem450 can induce axial motion, such as distal motion, with respect to one or more of thedistal end regions210b,310b,320b,330b,and/or340b.Axial motion of one or more of thecarrier member310, thepusher member320, thecover member330, and thesupport member340 and/or thetubular body210 can be attained, for example, by applying an axial force to theswitching system450.
Also, the triggeringsystem400 and switchingsystem450 can be configured for providing transverse or radial movement or bending from thecentral axis386 that allows the distal ends of the members of the tube set305 to be bent away from thelongitudinal axis386, which allows for enhanced placement of thetip220 with respect to the fistula.
To facilitate monitoring of the positioning of thecarrier assembly300 and/or the closure element, one or more of thedistal end regions210b,310b,320b,330b,and/or340bmay include radiopaque markers (not shown) or may be wholly or partially formed from a radiopaque material.
The triggeringsystem400 can be configured to overcome internal resistance such that the relative axial movement and/or positioning of the respectivedistal end regions310b,320b,330b,and340bof the tube set305 and/or thedistal end region210bof thelocator assembly200 are controlled in accordance with a predetermined manner when the triggeringsystem400 is activated. Thereby, axial movement and/or positioning of thedistal end regions310b,320b,330b,340b,and/or210bcan be initiated when at least a predetermined quantity of force is applied to theswitching system450. Stated somewhat differently, a force that is less than the predetermined quantity generally may be insufficient to activate the triggeringsystem400; whereas, when the force increases to a level that is greater than or substantially equal to the predetermined quantity, the triggeringsystem400 is configured to activate, move and/or position thedistal end regions310b,320b,330b,340b,and/or210bin accordance with the predetermined manner. The triggeringsystem400, once activated, can continue to move and/or position thedistal end regions310b,320b,330b,340b,and/or210bin accordance with the predetermined manner until theclosure element500 is deployed.
The triggeringsystem400, for example, can include one or more sets of cooperating detents for coupling the axial motion of thedistal end regions310b,320b,330b,and340bin accordance with a predetermined manner when the triggeringsystem400 is activated. The term “detents” refers to any combination of mating elements, such as blocks, tabs, pockets, slots, ramps, locking pins, cantilevered members, support pins, and the like, that may be selectively or automatically engaged and/or disengaged to couple or decouple thecarrier member310, thepusher member320, thecover member330, and thesupport member340 relative to one another and with respect to the triggeringsystem400, switchingsystem450, andhousing380. It will be appreciated that the cooperating detents as illustrated and described below are merely exemplary and not exhaustive. For example, the cooperating detents can include a first set of cooperating blocks and pockets for releasably coupling thesupport member340, thecarrier member310, thepusher member320, and thecover member330. When thecarrier assembly300 reaches a first predetermined distal position, thesupport member340 can be decoupled from thecarrier member310, thepusher member320, and thecover member330 and can be substantially inhibited from further axial movement. Thereby, thecarrier member310, thepusher member320, and thecover member330 may continue to be directed distally as thesupport member340 remains substantially stationary.
As shown inFIGS. 4A-4C, the cooperating detents can include acarrier block410, apusher block420, acover block430, and asupport block440, which can be configured to couple and decouple in accordance with the predetermined manner. For example, thecarrier block410 can be disposed on theproximal end region310aof thecarrier member310 and can include acarrier pin412 that extends from thecarrier block410; whereas, theproximal end region330aof thecover member330 and theproximal end region340athesupport member340 are respectively coupled with thecover block430 and thesupport block440. Acover pin432 can extend from thecover block430, and thesupport block440 can have asupport pin442, which extends from thesupport block440. Thesupport pin442, thecover pin432, and thecarrier pin412 each can be formed from a substantially rigid material, such as an alloy of nickel-titanium.
Thepusher block420 can be disposed on theproximal end region320aof thepusher member320 and forms asupport slot422a,acover slot422b,and acarrier slot422c.Thesupport slot422acan be configured to receive and releasable engage thesupport pin442 by which thesupport member340 can be coupled with, and decoupled from, thepusher member320. Thecover member330 can be coupled with, and decoupled from, thepusher member320 via thecover slot422b,which is configured to receive and releasable engage thecover pin432. Thecarrier slot422ccan be configured to receive and releasable engage thecarrier pin412 such that thecarrier member310 can be coupled with, and decoupled from, thepusher member320. Thecarrier block410, thepusher block420, thecover block430, and thesupport block440 can be respectively disposed substantially on the outer peripheries (i.e., outer surfaces)312b,322b,332b,and342bof the members of the tube set305, and can be configured to couple and decouple in accordance with the predetermined manner.
The triggeringsystem400 can further include one or more stops for engaging thepusher block420, thecover block430, and/or thesupport block440, respectively. As illustrated inFIGS. 4A-4B, a support stop460a,acover stop460b,and acarrier stop460ceach can be formed in thehousing380 and are configured to receive, and substantially inhibit further movement of, thesupport block440, thecover block430, and thecarrier block410, respectively, in accordance with the predetermined manner. For example, when an axial force is applied to the tube set305 via theswitching system450, thecover block430 can move distally within thehousing380, and the cover block430 approaches the cover stop460b.Upon being received by the cover stop460b,thecover block430 can be substantially locked in place, substantially preventing any further motion of thecover block430.
Resisting the axial force, thecover pin432 can provide a static load while the axial force is less than the predetermined quantity of force. As the axial force increases to a level that is greater than or substantially equal to the predetermined quantity, thecover pin432 can be displaced from thecover slot422b,decoupling thecover member330 from thecarrier member310, thepusher member320, and thesupport member340. Creating the internal resistance to be overcome by the triggeringsystem400, the static forces provided by thepins442,432, and412 is approximately proportional to a composition and cross-section of therespective pins442,432, and412 and/or a depth and a slope of therespective slots422a,422b,and422c.As desired, thepins442,432, and412 can be configured to provide static loads that are differing and/or substantially uniform.
FIG. 4C illustrates an embodiment of themedical device100 having the tube set305 and theclosure element500 being retained within thegarage370 and adjacent to thedistal end320bof thepusher tube320. Theclosure element500 can be configured into a retention orientation and slidably received over the distally-increasingcross-section318bof thedistal end region310bof thecarrier member310 and disposed about the outer surface312 of thecarrier member310 within thegarage370. If theclosure element500 has a reduced cross-section that is less than thecross-section318bof the distally-increasingcross-section318b,theclosure element500 can be temporarily radially deformed to a wider diameter in order to be received over thedistal end region310b.Also, as theclosure element500 is received over thedistal end region310b,the opposingtines520 are oriented toward thedistal end region310b.Theclosure element500 on thecarrier member310 can form the substantiallytubular closure element500 in the manner described in more detail herein. Also, theclosure element500 can be oriented so that the tines are pointed substantially in any direction, such as about 45 degrees, about 90 degrees, about 120 degrees and about 180 degrees or substantially proximally. The size of the garage and configuration of the tube set305 can be modulated to accommodate aclosure element500 in substantially any retention orientation, which can include members of the tube set305, such as thepusher tube320 having tapered, slotted, grooved, curved, inclined, declined, or other similar faces that contact theclosure element500.
After being received over thedistal end region310b,theclosure element500 can be disposed in thegarage370, and thetines520 are directed substantially distally. As desired, one or more of thetines520 can be disposed proximally of the distally-increasingcross-section318bof thedistal end region310b,and/or can be at least partially disposed upon, and contact, the distally-increasingcross-section318bof thedistal end region310b.To improve the engagement between theclosure element500 and the tissue of the fistula, the closure element can be disposed on thecarrier member310 such that thetines520 define a first plane that is substantially perpendicular to a second plane defined by theswitching system450 and/or the handles390 (collectively shown inFIG. 4D).
Once disposed in thegarage370, theclosure element500 can be retained on theouter surface312bof thecarrier member310 whendistal end region310bof thecarrier member310 and thedistal end region320bof thepusher member320 are slidably received within thelumen334 of thecover member330. When thecover member330 is properly positioned within thecarrier assembly300, thedistal end region330bof thecover member330 can extend over theclosure element500 and define the garage370 (i.e., annular cavity370) for retaining the closure element. As such, theclosure element500 is disposed substantially between theouter surface312bof thecarrier member310 and theinner surface332aof thecover member330 such that theclosure element500 maintains the substantially tubular configuration with thetines520 being directed substantially distally. As desired, thecover member330 may radially compress theclosure element500 maintains a compressed tubular configuration. The body of theclosure element500 can be disposed distally of thedistal end region320bof thepusher member320, or can engage thedistal end region320b,as desired.
Turning toFIG. 4D, the triggeringsystem400 may further include atube release system470 for inhibiting inadvertent advancement of the tube set305. Thetube release system470 is coupled with atube release member480, such as a rod, wire, or other elongate member. Thetube release member480 has aproximal end region480athat is disposed substantially between thepusher block420 and the housing380 (shown inFIG. 4A) and adistal end region480bthat is coupled with thetube release system470. Optionally, atab485 is coupled with theproximal end region480aof thetube release member480, and a pin (not shown) extends from thepusher block420 and is disposed substantially between thetab485 and a groove (not shown) formed in thehousing380. Thetube release system470 is configured to release the tube set305 when thetube release member480 is moved proximally, freeing thepusher block420.
Alocator release system490 for permitting thelocator220, theexpansion elements230, and/or the substantiallyflexible members231 of thelocator assembly200 to be manipulated and transition from the expanded state to the unexpanded state can be included with the triggeringsystem400. Thelocator release system490 can include a rod, wire, or other elongate member and has aproximal end region490aand adistal end region490b.Theproximal end region490aof thelocator release system490 can be coupled with, and configured to activate, the locator control system240 (shown inFIG. 2D), and thedistal end region490bextends beyond thepusher block420. Thereby, when thepusher block420 is advanced during deployment of theclosure element500, thecontrol block260 can be disengaged such that thedistal end region210b,locator220, theexpansion elements230, and/or the substantiallyflexible members231 of thelocator assembly200 to transition from the expanded state to the unexpanded state.
The operation of the triggeringsystem400 in accordance with one predetermined manner is illustrated inFIGS. 5A-5C. As shown inFIG. 5A, thedistal end region210bof thelocator assembly200 has been positioned as desired and thelocator220 has transitioned from the unexpanded state to the expanded state. While the locator control system240 (shown inFIG. 2D) maintains thedistal end region210bin a desired position and thelocator220 in the expanded state, a distally-directed axial force can be applied to the triggeringsystem400 via theswitching system450. Once the tube release member480 (shown inFIG. 4D) has been moved proximally to free thepusher block420, the tube set305 can be substantially freely slidable within thehousing380 and responds to the axial force by sliding distally from an initial predetermined position to a first predetermined position.
In the initial predetermined position, thecarrier member310, thepusher member320, thecover member330, and thesupport member340 can be coupled via theslots422c,422b,and422a(shown inFIG. 4C) and thepins412,432, and442 (shown inFIG. 4C). Stated somewhat differently, thesupport pin442, thecover pin432, and thecarrier pin412 can be respectively disposed within, and engaged by, thesupport slot422a,thecover slot422b,and thecarrier slot422csuch that thecarrier block410, thepusher block420, thecover block430, and thesupport block440 are coupled as illustrated inFIG. 4C. Therefore, thecarrier member310, thepusher member320, thecover member330, and thesupport member340 each can slide distally from the initial predetermined position to the first predetermined position in response to the axial force.
FIG. 5B illustrates the positions of thecarrier member310, thepusher member320, thecover member330, and the support member340 (FIG. 4C) upon reaching the first predetermined position. In the first predetermined position, thesupport block440 and thecover block430 can respectively engage the support stop460aand the cover stop460b.Thereby, the support stop460acan receive, and substantially inhibit further movement of, thesupport block440 and, therefore, thesupport member340; whereas, the cover stop460breceives, and substantially inhibits further movement of, thecover block430 and, therefore, thecover member330. Although thesupport block440 and thecover block430 can engage the support stop460aand the cover stop460bin the first predetermined position, it will be appreciated that thesupport block440 can engage the support stop460aand thecover block430 can engage the cover stop460bin different predetermined positions. In other words, the predetermined manner can include any number of predetermined positions, each predetermined position being associated with any number of theblocks410,420,430, and440 engaging any number ofrelevant stops460a,460b,and460c.
To continue distally from the first predetermined position, thecarrier member310 and thepusher member320 can be decoupled from thecover member330 and thesupport member340 by disengaging thesupport pin442 and thecover pin432 from thesupport slot422aand thecover slot422b,respectively. In the manner described in more detail above with reference toFIGS. 4A-4C, thesupport pin442 and thecover pin432 each resist the axial force. While the axial force is less than the combined static force provided by thesupport pin442 and thecover pin432, thecarrier member310 and thepusher member320 remain coupled with thecover member330 and thesupport member340. As the axial force increases to a level that is greater than or substantially equal to the combined static force, thesupport pin442 and thecover pin432 are respectively displaced from thesupport slot422aand thecover slot422b,decoupling thecarrier member310 and thepusher member320 from thecover member330 and thesupport member340. Thereby, thecover member330 and thesupport member340 can be inhibited from further distal movement and remain substantially stationary; whereas, thecarrier member310 and thepusher member320 can proceed distally toward a second predetermined position.
Thepusher member320 and thecarrier member310 can continue distally until the second predetermined position is reached as shown inFIG. 5C. In the second predetermined position, thecarrier block410 can engage the carrier stop460c.Whereby, the carrier stop460ccan receive, and substantially inhibit further movement of, thecarrier block410 and, therefore, thecarrier member310. To continue distally from the second predetermined position, thepusher member320 can be decoupled from thecarrier member310 by disengaging thecarrier pin412 from thecarrier slot422c.In the manner described in more detail above with reference toFIG. 4B-C, thecarrier pin412 resists the axial force. While the axial force is less than the static force provided by thecarrier pin412, thepusher member320 remains coupled with thecarrier member310.
As the axial force increases to a level that is greater than or substantially equal to the static force, thecarrier pin412 can be displaced from thecarrier slot422c, decoupling thepusher member320 from thecarrier member310. Thereby, thecarrier member310 can be inhibited from further distal movement and remains substantially stationary; whereas, thepusher member320 proceeds distally to deploy theclosure element500 and to activate the locator release system490 (shown inFIG. 4D) such that thelocator220, theexpansion elements230, and/or the substantiallyflexible members230′ of thelocator assembly200 transition from the expanded state to the unexpanded state. The axial force that is applied to overcome the static force associated with the first predetermined position is sufficient to overcome the static forces associated with the subsequent predetermined positions, to deploy theclosure element500, and to activate thelocator release system490 such that the triggeringsystem400 operates in one substantially-continuous motion.
It will be appreciated that the triggeringsystem400 can include an energy storing element (not shown), which can be disposed substantially between thehousing380 and theblocks410,420,430, and440 and which can be configured to store potential energy for moving the tube set305 from the initial predetermined position through the other predetermined positions, deploying theclosure element500, and/or activating thelocator release system490. The energy-storing element can be configured store the potential energy when the tube set305 is in the initial predetermined position and to release the potential energy, when activated, such that the tube set305 travels through the predetermined positions at a substantially constant and continuous rate. For example, the energy-storing element can include one or more springs (not shown). Each of the springs can be in a compressed state when the tube set305 is in the initial predetermined position and released from the compressed state when theswitching system450 of the triggeringsystem400 is activated.
A. Distal End FlexibilityIn one embodiment, the closure device includes a flexible distal portion, which is flexible from the distal tip to a predefined location on the shaft. The flexibility of the distal portion of the closure device enables the locator to be selectively bent around corners or directed through intersections of the body lumen during placement of the tip of the closure device. The flexible distal portion also allow the tip to be inserted into the fistula that can be at an angle compared to the body lumen, which can allow the tip to be directed at an angle with respect to the shaft, fistula, and body lumen, such as from 0 to 180 degrees. However, the flexibility can be controlled to be any angle from the shaft that allows the tip, and thereby the closure element to be deployed to close the fistula. This can include flexibility that allows for the tip to be inserted into or through the fistula so that the locator can locate a surface of the fistula and so that the closure element can be applied to close the fistula as shown herein. Often, the closure device will be delivered through a body lumen in which the fistula is located so that the fistula opening and/or fistula conduit is 120 degrees or less with respect to the shaft, which can be less than 90 degrees or less than 45 degrees. Also, the closure device can be delivered through the fistula. Thus, the flexibility allows the tip to be inserted into the fistula in order for the closure element to gather the tissue defining the fistula and pull the tissue together to close the fistula.
For example, trachea-esophageal fistula, which is not close to the mouth opening, requires navigation over the tongue and down through the back of the throat into either the airway or the esophagus. Such delivery requires flexibility, especially when the fistula is perpendicular or at an angle from 90 degrees to 180 degrees with respect to the route of delivery. As such, the distal end of the shaft can bend to an angle of up to about 45 degrees, up to about 90 degrees, up to about 120 degrees, and up to about 180 degrees, which enables the tip to be inserted into fistula at any angle.
B. Shaft DiameterIn one embodiment, the closure device has an outer diameter that is larger than a percutaneous incision for the placement of a standard catheter, such as those used in an arteriotomy. Previous medical devices for closing incisions in blood vessels after catheter procedure have small dimensions so as to fit through the smallest incisions possible. However, the closure device of the present invention can be sized much larger when delivered through a body lumen that opens to the outside environment, such as through the mouth, nostrils, anus, vagina, and urethra, instead of being delivered through an incision. Often, incisions and catheter diameters have a circumference of about 13.56 mm, which is commonly referred to as13F through about 1.56 mm, which is commonly referred to as11F. The outer diameter of the closure device can be configured much larger because of the site of entry into the human body; however, smaller diameters may be employed in some instances. For example, the outer diameter of the shaft and/or carrier assembly can from about 0.2 cm to about 1 cm, more preferably from about 0.3 cm to about 0.75, and most preferably from about 0.4 cm to about 0.6 cm, or larger than about 0.17 inches.
In another example, the outer dimension (e.g., outer diameter) of a closure device in accordance with the present invention can be larger than about 0.17 inches, more preferably larger than about 0.2 inches, and the dimension can be larger than about 0.50 inches, about 0.75 inches, and about 1 inch in some instances, such as for closing a fistula in the colon, vagina, and esophagus. This can allow for the closure element to be retained in the garage at an angle other than congruent with the longitudinal axis of the garage and retaining portion of the shaft. Accordingly, the closure element can be retained in the garage at an angle from the longitudinal axis of from about 0 to about 45 degrees, about 45 degrees to about 90 degrees, about 90 degrees to about 120 degrees, and about 120 degrees to about 180 degrees such that the tines are directed proximally rather then distally as described in more detail herein.
C. Shaft LengthIn one embodiment, the shaft of the closure device has a length to be delivered into a normal body opening to the site of the fistula. This can allow for the medical device to be extremely elongate in a length similar to a catheter. Previous medical devices for closing incisions in blood vessels after a catheter procedure have relatively short lengths because they are utilized in a manner that delivers the tip through an incision in the skin and tissue directly outward from the incision in the blood vessel into which the catheter has been deployed. Traversing through the skin and underlying tissue to a blood vessel that receives a catheter requires a length much shorter than the length needed for a closure devoice of the present invention to be delivered into a normal body opening, through the connecting body lumen or conduit, and into the fistula in a manner that allows for a closure element to be applied to close the fistula. Accordingly, the length can be longer than about 5 cm, between about 10 cm to about 200 cm, more preferably about 20 cm to about 150 cm, and most preferably about 30 cm to about 100 cm. Also, the length of the shaft can be tailored for the type of fistula to be closed, which allows for the length to be sufficient for treating a specific fistula, such as those recited herein.
D. LocatorIn one embodiment, the locator of the closure device has a length sufficient to be passed through the fistula canal from one opening to the opposite opening. Normally, the fistula is formed by the tissue between adjacent body lumen, organs, or the like, which forms a fistula canal having a length much longer than the thickness of a blood vessel. The length of the fistula canal can be traversed with a locator having a length sufficient to be passed through the fistula canal so that the locator wings can contact tissue opposite from the opening in which the distal end of the closure element applier is disposed. Previous medical devices for closing incisions in blood vessels after a catheter procedure have relatively short locator lengths because the locator only has to be passed through the thickness of a blood vessel, which is a relatively short distance.
In some instances, traversing through the fistula canal can require a locator length much longer than previous locators configured for closing a hole in a blood vessel. Accordingly, the length of the locator of the present invention can be at least about 0.25 cm, between about 0.3 cm to about 3 cm, more preferably about 0.4 cm to about 2 cm, and most preferably about 0.5 cm to about 1 cm. Also, the length of the shaft can be tailored for the type of fistula to be closed.
In one embodiment, the locator wings of the locator can be of a sufficient size to contact tissue of the fistula to allow for identification of the location of the tip of the closure device with respect to the fistula. Previous medical devices for closing incisions in blood vessels after a catheter procedure have locator wings of the locator with smaller dimensions because they only flair large enough to contact the tissue surrounding the opening of the incision in the blood vessel, which is usually as small as possible. However, the dimension of the flared locator wings of the present invention can be sized much larger because the size of a fistula may be larger, irregular, and more difficult to locate than a controlled incision. The present invention provides locator wings that can flare to a diameter larger than about 0.25 cm, between about 0.3 cm to about 5 cm, more preferably about 0.4 cm to about 2.5 cm, and most preferably about 0.5 cm to about 1 cm.
Of course, the sizes (e.g., lengths and diameters) of the shaft, locator, locator wings, and the like can be configured to be larger or smaller depending on the size of the fistula and its location in the body. For example, the sizes can allow for a working channel to be disposed internally of the locator assembly, where channel can have a size sufficient for passing wires therethrough, such as a guide wire.
In one embodiment, the medical device is configured such that the distal portion of the shaft can be controlled for placement of the tip with respect to the fistula so that the closure element can be deployed in order to close the fistula. This can include the distal portion be sufficiently flexible and/or controllable to negotiate through a body lumen and to turn into a fistula opening. The distal portion (e.g., tip) of the medical device of the present invention can be delivered to the fistula in a manner that any medical device, such as a catheter or endoscope, is delivered to a site within a body of a subject. The configurations, components, equipment, and techniques for the delivery of catheters, endoscopes, and the like to specific sites within the body of a subject can be employed for delivering the tip of the medical device to a fistula. This can include the use of guidewires, delivery catheters, fluoroscopy, endoscopes, scopes, combinations thereof, and the like. For example, a guidewire can be delivered to the fistula as is commonly performed, and the medical device is delivered to the fistula by being directed over the guidewire, and the guidewire is removed at some point, such as before or during deployment of the closure element into the tissue of the fistula. In another example, the distal portion of the medical device is delivered to the fistula by direct visual control or with fluoroscopy, where the medical device includes a controller that controls the deflection of the tip during delivery to the fistula and within the fistula. In another example, the medical device is associated with or included with an endoscope, and the endoscope is delivered to the fistula to deliver the distal portion and closure element to the appropriate position. Also, the distal tip of the medical device can be delivered to a fistula by controlling bending members and bending components as described herein that selectively bend the tip to point in a radial or lateral direction compared to the axis or longitudinal direction of the medical device.
The medical device can include a tip deflection controller system that includes a controller that can move the tip in the directions described herein during placement of the tip of the closure element applier to and/or within the fistula. A multidirectional controller, such as those used in the delivery of catheters, can be used to deflect the tip any one direction by at least one bending member (e.g., rod, tube, wire, etc.) and in the opposite direction within the same plane by a second bending member (e.g., rod, tube, wire, etc). The tip deflection controller system can actuate bending members as described in or similar toFIGS. 4A-4C andFIGS. 5D-5E. Any number of bending member can be used to provide for multiple angles of deflection. For example of deflection in opposite directions, the bending members extend into opposing off-axis lumens within the tip section of the closure element applier. So that the tip section can bend in both directions in the same plane, the puller wires and their associated lumens must be located along a diameter of the tip section.
For example, U.S. Pat. No. 6,210,407, the disclosure of which is incorporated herein by reference, is directed to a bi-directional catheter comprising two puller wires and a control handle having at least two moveable members longitudinally movable between first and second positions. The same principle, components, and operation can be applied to the medical device of the present invention and any number of pull wires (e.g., bending member) can be used for multiple planes of deflection. The proximal end of each puller wire is connected to an associated movable member of the control handle. Proximal movement of a movable member relative to the shaft and carrier assembly results in proximal movement of the puller wire associated with that movable member relative to the shaft, and thus deflection of the tip section in the direction of the lumen in which that puller wire extends.
In another example, U.S. Pat. No. 6,171,277, the disclosure of which is incorporated herein by specific reference, is directed to a bidirectional steerable catheter having a control handle that houses a generally-circular spur gear and a pair of spaced apart rack gears. Each rack gear is longitudinally movable between first and second positions, whereby proximal movement of one rack gear results in rotational movement of the spur gear, and correspondingly distal movement of the other rack gear. Two puller wires extend from the control handle whose the distal ends are fixedly attached to the tip section, and whose proximal ends are each anchored to a separate associated rack gear in the control handle. Proximal movement of a rack gear and its associated puller wire relative to the catheter body results in deflection of the tip section in the direction of the off axis lumen into which that puller wire extends.
In another example, U.S. Pat. No. 6,198,974, the disclosure of which is incorporated herein by specific reference, is directed to a bi-directional catheter comprising a control handle. At their proximal ends, two pairs of puller wires are attached to movable pistons in the control handle. Each piston is controlled by an operator using a slidable button fixedly attached to each piston. Movement of selected buttons results in deflection of the tip section into a generally planar “U”- or “S”-shaped curve
In another example, U.S. Pat. No. 5,891,088, the disclosure of which is incorporated herein by specific reference, is directed to a steering assembly with asymmetric left and right curve configurations. Proximal ends of left and right steering wires are adjustably attached to a rotatable cam housed in a control handle. The rotatable cam has first and second cam surfaces which may be configured differently from each other to accomplish asymmetric steering.
In another example, the shaft has an elongated shaft body, a distal shaft section with first and second diametrically-opposed off-axis lumens, and a control handle which includes a steering assembly having a lever structure carrying a pair of pulleys for simultaneously drawing and releasing corresponding puller wires (e.g., bending members) to deflect the distal section of the shaft. In particular, the pulleys are rotatably mounted on opposing portions of the lever structure such that one pulley is moved distally as the other pulley is moved proximally when the lever structure is rotated. Because each puller wire is trained on a respective pulley, rotation of the lever structure causes the pulley that is moved proximally to draw its puller wire to deflect the tip section in the direction of the off-axis lumen in which that puller wire extends another embodiment, the control handle includes a deflection knob that is rotationally coupled to the lever structure which enables the user to control deflection of the tip section with, preferably, a thumb and an index finger, when grasping the control handle. The closure element applier may also include a tension adjustment mechanism for adjusting the tightness of the deflection knob. Optionally, the adjustment mechanism can include a cap and a dial rotationally coupled to each other, a friction nut, and a screw rotationally coupled to cap, whereby rotation of the dial selectively increases or decreases the frictional bearing on the lever structure
The same type of or similar mechanics and components discussed above can be incorporated into the closure element applier so that the tip can be delivered to a fistula and turned to that the tip can be directed into or even inserted into the fistula. With reference toFIGS. 4A-4D, the controller, mechanics, and components described for deflection of the distal end of the shaft, and thereby the locator assembly and carrier assembly, can be included with thehousing380. As such, the various elongate members can represent members that are actuated in order to deflect or bend the distal end and tip in a desired direction and in a desired angle. Also, the controllers described herein or others well known in the art can be configured as distal end and/or tip deflection controllers that are operated in order to induce the components to bend the distal end and/or tip as described.
In one embodiment, the actuators for actuating the medical device can be configured in any manner that allows for operation of the medical device as described herein, which include deliver of the distal portion of the medical device to the fistula with the tip being disposed in a position suitable for deploying the closure element into the tissue adjacent to the fistula so as to close the fistula. As such, the actuators can be triggers, knobs, wheels, buttons, levers, switches, and the like. This can allow for any type of actuator to be included in the medical device to operate the different components of the medical device, which includes: maneuvering the tip of the shaft; retraction of the garage; movement of the pusher, carrier, cover, support, and other members associated with retention and deployment of the closure element; deployment of the closure element; operation of the locator, including insertion into the fistula and expansion of the wings and identification of the fistula location; combinations thereof, and the like.
III. Closure ElementA closure element in accordance with the present invention can have a variety of shapes, sizes, and modes of operation. A star closure element or circular closure element with a central lumen and tines pointing toward the lumen can be configured for being disposed on a carrier member can be convenient for storage in the garage, and for being delivered into tissue for fistula repair. The closure element can be similar in form and function to closure elements used for closing incisions in blood vessels. Such a closure element can be configured to be retained within the garage in an orientation to optimize space and deployment potential and efficacy, and can be configured for automatically changing to an orientation that grabs an optimum amount of tissue before reverting to the normal or set orientation that pulls the grabbed tissue together to close the fistula. The closure element can also be configured to flare to a larger diameter during the process of changing from the retained or delivery orientation to the orientation for penetrating and grabbing tissue. Additionally, various materials can be used for a closure element that has the functionality and characteristics as described herein. Moreover, the closure element can be coated with a polymer/drug coating so that a drug can aid in closing and sealing the fistula. Also, a drug can be used for treating complications or infections associated with fistulas or the process of closing the fistula.
FIGS. 6A-6G illustrate one embodiment of a closure element (also referred to herein as a “star closure element”)500 in accordance with the present invention. Theclosure element500 can have a generally annular-shape body510 (shown inFIG. 6A-6B) defining achannel540 and one or more barbs and/or tines520 (shown inFIGS. 6A-6B) for receiving and engaging tissue adjacent or within a fistula. While only twotines520 are shown, any number of tines can be included in the closure element. Although theclosure element500 has a natural shape and size that is set as a memory shape, theclosure element500 can be deformed into other shapes and sizes, as desired, and is configured to return to the natural shape and size when released. For example, theclosure element500 can have a natural, planar configuration with opposingtines520 and anatural cross-section530 as shown inFIGS. 6A-6B. Thenatural cross-section530 of theclosure element500 can be reduced to form a reducedclosure element500athat has a natural, planar configuration with opposingtines520 and a reducedcross-section530aas shown inFIGS. 6C-6D. By rotating the opposingtines520 axially as shown inFIG. 6E, the reducedclosure element500acan be further deformed to form a substantiallytubular closure element500b(shown by dashed lines inFIG. 6E and shown along the central axis inFIG. 6F) having the reducedcross-section530aandaperture diameter550 as well as being in a substantially tubular configuration with thetines520 in an axial configuration.FIG. 6G illustrates a side profile of theclosure element500bin the substantially tubular configuration.FIG. 6H illustrates a side profile of theclosure element500cin which the body is in the substantially tubular configuration; however, thetines521 are directed at any one of various angles from 0 degree (distally) to 180 degrees (proximally).
The closure element can have any number of tines. The tines can be equal in length or some can be longer than others.
As shown inFIGS. 1G-1H, the closure element can be a helical or wound wire or spring. The closure element can be configured to be similar to an unwound spring so as to be threaded through the tissue around the fistula canal.
Being configured to draw the tissue surrounding a fistula or within a fistula together so as to be substantially close, theclosure element500 can be formed from any suitable material, including any biodegradable material, any shape memory alloy, such as alloys of nickel-titanium, or any combination thereof. Additionally, it is contemplated that the closure element may be coated with a beneficial agent or be constructed as a composite, wherein one component of the composite would be a beneficial agent. As desired, theclosure element500 may further include radiopaque markers (not shown) or may be wholly or partially formed from a radiopaque material to facilitate observation of theclosure element500 using fluoroscopy or other imaging systems. Exemplary embodiments of a closure element are disclosed in U.S. Pat. Nos. 6,197,042, and 6,623,510, and in co-pending application Ser. Nos. 09/546,998, 09/610,238, and 10/081,726, which are expressly incorporated herein by reference.
In one embodiment, the closure element is configured to flare in an amount sufficient so that the times are capable of penetrating into the tissue defining the fistula. Accordingly, the closure element and tines are configured to flare to a maximum size and/or diameter during deployment so as to maximize the amount of tissue grabbed by the tines and drawn inward to close the fistula. This can include when the closure element is applied to as shown in theFIGS. 1A-1I. The closure element is dimensioned so as to be retained and/or deployed in a manner that flares and extends the tines further outwardly from the fistula opening and/or into the tissue around the fistula opening, which allows for more tissue to be grabbed and pulled together. The present invention provides for the closure element to flare to a diameter sufficient to close a fistula. Since fistulas can vary greatly in the diameter of the opening, the closure elements correspondingly vary so as to be capable of penetrating tissue surrounding the fistula opening. Also, the tines can vary in size with some being larger than others. The closure element diameter and/or tines allow for more tissue to be pulled together and are suitable for closing fistulas without causing more trauma from larger incisions when the closure device is delivered through a natural opening.
In one embodiment, the closure element is configured to extend the tines further outward during deployment before turning and penetrating into the tissue. With respect to the longitudinal axis of the garage, the tines are directed radially away from the axis to form a larger and/or maximum diameter before turning and penetrating into the tissue surrounding the opening of the fistula. The superelastic property of the closure element allows for such a configuration and function during deployment and closure of the fistula, which can be likened to the closure element body and tines being more flat and extending perpendicularly (or angle between 45 degrees to 90 degrees) before turning inwardly to a more tubular shape, and then to the closed and natural shape with the tines pointing more inwardly. As such, the tines would make substantially a 90 degree turn during the deployment into the tissue to close the fistula.
In one embodiment, the closure element body and/or tines (e.g., extended tines) have barbs, hooks, spikes, prongs, protrusions, roughened surfaces, and the like in order to increase the efficiency of tissue contact and grab. As such, the closure element has increased contact points for increasing the contact with the tissue during deployment.
FIGS. 7A-7B illustrate an embodiment of a collapsible tubular closure element560. As shown in the tubular orientation ofFIG. 7A, theclosure element560aincludes atubular body562 that is defined bybody elements564 that intersect at various locations to leave a plurality ofapertures566 disposed therebetween. Thebody562 includes a plurality of tissue-grabbingmembers568 disposed thereon. The tissue-grabbingmembers568 can be tines, spikes, blades, hooks, barbs, claws, and the like that are configured to penetrate and grab skin.FIG. 7B shows theclosure element560bin the collapsed orientation. Such a closure element560 can be utilized substantially as described herein, and the closure element applier can be modified to accommodate the tubular closure element560 for delivery and deployment into a fistula. The tubular closure element560 can be advantageous for being inserted into the fistula canal and then being released which causes thebody562 to revert to the collapsed orientation which is substantially flat. The collapsed orientation provides theapertures566 for the tissue to grow between in order to repair the fistula. Also, the tubular closure element560 can be utilized with or without a locator.
Additionally, the collapsible tubular closure element560 can be configured to be substantially similar to a stent having tissue-grabbingmembers568; however, it is deployed in the expanded orientation into the fistula and then collapses to a narrower tube to pull the fistula together. Accordingly, the collapsible tubular closure element560 can function as an anti-stent by operating in the opposite manner of a stent.
FIGS. 8A-8B illustrate an embodiment of a self-rolling closure element570.FIG. 8A shows the self-rollingclosure element570ain a substantially flat orientation. The self-rollingclosure element570ais shown to have abody572 with a plurality of tissue-grabbingmembers574 disposed thereon. When the self-rollingclosure element570ais inserted into a fistula, it transformed from being substantially flat to a rolledclosure element570bas shown inFIG. 8B. Such a closure element570 can be utilized substantially as described herein, and the closure element applier can be modified to accommodate the self-rolling closure element570 for delivery and deployment into a fistula. The self-rolling closure element570 can be advantageous for being inserted into the fistula canal and then being released which causes thebody572 to revert to the rolled orientation so as to pull the tissue of the fistula together. The self-rolling closure element570 can includeapertures576 for the tissue to grow between in order to repair the fistula. Also, the closure element570 can be utilized with or without a locator. The self-rolling closure element570 can also be configured in the opposite manner in which it is delivered rolled as shown inFIG. 8B and then it unrolls to the orientation shown inFIG. 8A in order to repair the fistula. In any event, the change in orientation allows for the tissue-grabbingmembers574 to pull the tissue of the fistula together.
FIGS. 9A-9B illustrate a side view an embodiment of a reverse closure element580.FIG. 9A shows thereverse closure element580ain a substantially an “S” orientation. Thereverse closure element580ais shown to have abody582 with a first tissue-grabbingmember584adisposed thereon and an oppositely disposed second tissue-grabbingmember584b.When thereverse closure element580ais inserted into a fistula, it transformed from being substantially “S” shaped to substantially an “8”shape570b(FIG. 9B) with the tissue grabbing members584a-bpassing the body in order to grab and pull the tissue of the fistula closed. Such a closure element580 can be utilized substantially as described herein, and the closure element applier can be modified to accommodate the reverse closure element580 for delivery and deployment into a fistula. The reverse closure element580 can be advantageous for being inserted into the fistula canal and then being released which causes thebody582 to revert to the substantially “8” shapedclosure element580bin a manner that pulls the tissue from opposite openings of the fistula together. The closure element580 an also pull opposite portions of tissue from within the fistula canal. The reverse closure element580 can be annular, have a plurality of reverse tissue-grabbing members584a-b,be flat, or other similar configuration. Also, the closure element580 can be utilized with or without a locator.
FIGS. 10A-10B illustrate a side view an embodiment of a clam closure element590.FIG. 10A shows theclam closure element590ain a substantially an open clam orientation. Theclam closure element590ais shown to have two opposite body portions592a-b,each body portion having a corresponding tissue-grabbing member594a-bdisposed thereon. When theclam closure element590ais inserted into a fistula, it transformed from being in a substantially open clam shape to substantially aclosed clam shape590b(FIG. 9B) with the tissue grabbing members594a-bpassing by each other in order to grab and pull the tissue of the fistula closed. During deployment, the claim closure element590 passes through substantially a “C” shape. Such a closure element590 can be utilized substantially as described herein, and the closure element applier can be modified to accommodate the clam closure element580 for delivery and deployment into a fistula. The clam closure element580 can be advantageous for being inserted into the fistula canal and then being released which causes the body segments592a-bto revert to the substantially closed clam shapedclosure element580bin a manner that pulls the tissue from opposite openings of the fistula together. It can also be used applied to the tissue around the opening of the fistula. The clam closure element590 can be annular, have a plurality of tissue-grabbing members594a-b,be flat, or other similar configuration. Also, the closure element590 can be utilized with or without a locator.
In one embodiment, the closure element has increased flexibility and/or decreased mechanical strength with respect to the relaxed orientation due to the fistula not being a high pressure system. Previous closure elements employed in closing incisions formed in blood vessels have been designed with decreased flexibly and/or increased mechanical strength due to the blood vessel being a high pressure network with blood pressure against the arterial walls. Accordingly, closure elements configured for closing an incision in a blood vessel had to be configured to resist blood pressure. The closure elements of the present invention can be configured for application in a system with much less pressure requirements. That is, a closure element configured for closing a fistula does not have the same strength and mechanical requirements for closing an incision in a blood vessel. Thus, the closure elements for closing a fistula can be comparatively more flexible and have decreased mechanical strength.
In one embodiment, the closure element can be prepared from a biodegradable material. This allows for the closure element to be degraded over time after being inserted into the body to close the fistula. Biodegradable polymers can be formed into closure elements to have the properties described herein. The list of biocompatible polymers includes such biodegradable polymers that would be suitable for preparing a biodegradable closure element of the present invention.
In one embodiment, the closure element is coated with an active pharmaceutical ingredient with or without a polymeric carrier. The active pharmaceutical ingredient can be any drug; however, it is preferable for it to increase tissue growth
The polymeric coating and drug are configured to cooperate so as to form a diffusion pathway (e.g., lipophilic, hydrophilic, and/or amphipathic) with tissue when the closure element penetrates the tissue and closes the fistula. This allows for the drug to preferentially diffuse into the tissue instead of into a body fluid passing over the closure element.
A biocompatible closure element or polymeric coating on the closure element can also be provided so that the closure element can be loaded with and deliver beneficial agents or drugs, such as therapeutic agents, pharmaceuticals and radiation therapies. Accordingly, the polymeric closure element and/or coating material can contain a drug or beneficial agent to improve the use of the closure element. Such drugs or beneficial agents can include antithrombotics, anticoagulants, antiplatelet agents, thrombolytics, antiproliferatives, anti-inflammatories, agents that inhibit hyperplasia, inhibitors of smooth muscle proliferation, antibiotics, growth factor inhibitors, or cell adhesion inhibitors, as well as antineoplastics, antimitotics, antifibrins, antioxidants, agents that promote endothelial cell recovery, antiallergic substances, radiopaque agents, viral vectors having beneficial genes, genes, siRNA, antisense compounds, oligionucleotides, cell permeation enhancers, and combinations thereof. Another example of a suitable beneficial agent is described in U.S. Pat. No. 6,015,815 and U.S. Pat. No. 6,329,386 entitled “Tetrazole-containing rapamycin analogs with shortened half-lives”, the entireties of which are herein incorporated by reference.
More specific examples of drugs that can be included in the coating of the closure element include any of the following: anti-proliferative/antimitotic agents including natural products such as vinca alkaloids (i.e. vinblastine, vincristine, and vinorelbine), paclitaxel, epidipodophyllotoxins (i.e. etoposide, teniposide), antibiotics (dactinomycin (actinomycin D) daunorubicin, doxorubicin and idarubicin), anthracyclines, mitoxantrone, bleomycins, plicamycin (mithramycin) and mitomycin, enzymes (L-asparaginase which systemically metabolizes L-asparagine and deprives cells which do not have the capacity to synthesize their own asparagine); antiplatelet agents such as G(GP) IIb/IIIainhibitors and vitronectin receptor antagonists; anti-proliferative/antimitotic alkylating agents such as nitrogen mustards (mechlorethamine, cyclophosphamide and analogs, melphalan, chlorambucil), ethylenimines and methylmelamines (hexamethylmelamine and thiotepa), alkyl sulfonates-busulfan, nirtosoureas (carmustine (BCNU) and analogs, streptozocin), trazenes-dacarbazinine (DTIC); anti-proliferative/antimitotic antimetabolites such as folic acid analogs (methotrexate), pyrimidine analogs (fluorouracil, floxuridine, and cytarabine), purine analogs and related inhibitors (mercaptopurine, thioguanine, pentostatin and 2-chlorodeoxyadenosine {cladribine}); platinum coordination complexes (cisplatin, carboplatin), procarbazine, hydroxyurea, mitotane, aminoglutethimide; hormones (i.e. estrogen); anti-coagulants (heparin, synthetic heparin salts and other inhibitors of thrombin); fibrinolytic agents (such as tissue plasminogen activator, streptokinase and urokinase), aspirin, dipyridamole, ticlopidine, clopidogrel, abciximab; antimigratory; antisecretory (breveldin); anti-inflammatory: such as adrenocortical steroids (cortisol, cortisone, fludrocortisone, prednisone, prednisolone,6a-methylprednisolone, triamcinolone, betamethasone, and dexamethasone), non-steroidal agents (salicylic acid derivatives i.e. aspirin; para-aminophenol derivatives i.e. acetaminophen; indole and indene acetic acids (indomethacin, sulindac, and etodalac), heteroaryl acetic acids (tolmetin, diclofenac, and ketorolac), arylpropionic acids (ibuprofen and derivatives), anthranilic acids (mefenamic acid, and meclofenamic acid), enolic acids (piroxicam, tenoxicam, phenylbutazone, and oxyphenthatrazone), nabumetone, gold compounds (auranofin, aurothioglucose, gold sodium thiomalate); immunosuppressives: (cyclosporine, tacrolimus (FK-506), sirolimus (rapamycin), everolimus, azathioprine, mycophenolate mofetil); angiogenic agents: vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF); angiotensin receptor blockers; nitric oxide donors; antisense oligionucleotides and combinations thereof; cell cycle inhibitors, mTOR inhibitors, and growth factor receptor signal transduction kinase inhibitors; retenoids; cyclin/CDK inhibitors; HMG co-enzyme reductase inhibitors (statins); and protease inhibitors. Also, it should be recognized that many active agents have multiple pharmaceutical uses other than those specifically recited.
The closure element (i.e., fistula closure element) of the present invention can be made of a variety of biocompatible materials, such as, but not limited to, those materials which are well known in the art of endoprostheses. Generally, the materials for the closure element can be selected according to the structural performance and biological characteristics that are desired, such as superelasticity, flexibility, size, shape, changes in orientation, biodegradability, drug elution, and the like.
In one configuration, the closure element can be made of a single material or of multiple layers, with at least one layer being applied to a primary material. This can include a metal primary material and polymer/drug topcoat or a different metal top layer. The multiple layers can be resiliently flexible materials or rigid and inflexible materials, and selected combinations thereof. For example, materials such as Ti3A12.5V, Ti6Al4V, 3-2.5Ti, 6-4Ti and platinum may be particularly good choices for adhering to a flexible material, such as, but not limited to, nitinol and providing good crack arresting properties. The use of resiliently flexible materials can provide force-absorbing characteristics, which can also be beneficial for absorbing stress and strains, which may inhibit crack formation at high stress zones. Also, the multiple layers can be useful for applying radiopaque materials. For example, types of materials that are used to make a closure element can be selected so that the closure element is capable of being in a first orientation (e.g., delivery orientation) during placement and capable of transforming to a second orientation (e.g., deploying orientation) when deployed to close the fistula.
Embodiments of the closure element can include a material made from any of a variety of known suitable biocompatible materials, such as a biocompatible shaped memory material (SMM). For example, the SMM can be shaped in a manner that allows for a delivery orientation while within the garage of the shaft of the medical device, but can automatically retain the memory shape of the closure element once deployed from the garage and into the tissue to close the fistula. SMMs have a shape memory effect in which they can be made to remember a particular shape. Once a shape has been remembered, the SMM may be bent out of shape or deformed and then returned to its original shape by unloading from strain or heating. Typically, SMMs can be shape memory alloys (SMA) comprised of metal alloys, or shape memory plastics (SMP) comprised of polymers. The materials can also be referred to as being superelastic.
Usually, an SMA can have an initial shape that can then be configured into a memory shape by heating the SMA and conforming the SMA into the desired memory shape. After the SMA is cooled, the desired memory shape can be retained. This allows for the SMA to be bent, straightened, twisted, compacted, and placed into various contortions by the application of requisite forces; however, after the forces are released, the SMA can be capable of returning to the memory shape. The main types of SMAs are as follows: copper-zinc-aluminium; copper-aluminium-nickel; nickel-titanium (NiTi) alloys known as nitinol; nickel-titanium platinum; nickel-titanium palladium; and cobalt-chromium-nickel alloys or cobalt-chromium-nickel-molybdenum alloys known as elgiloy alloys. The temperatures at which the SMA changes its crystallographic structure are characteristic of the alloy, and can be tuned by varying the elemental ratios or by the conditions of manufacture. This can be used to tune the closure element so that it reverts to the memory shape to close the fistula when deployed at body temperature and when being released from the garage.
For example, the primary material of a closure element can be of a NiTi alloy that forms superelastic nitinol. In the present case, nitinol materials can be trained to remember a certain shape, retained within the garage in the shaft, and then deployed from the garage so that the tines penetrate the tissue as it returns to its trained shape and closes the fistula. Also, additional materials can be added to the nitinol depending on the desired characteristic. The alloy may be utilized having linear elastic properties or non-linear elastic properties.
An SMP is a shape-shifting plastic that can be fashioned into a closure element in accordance with the present invention. Also, it can be beneficial to include at least one layer of an SMA and at least one layer of an SMP to form a multilayered body; however, any appropriate combination of materials can be used to form a multilayered endoprosthesis. When an SMP encounters a temperature above the lowest melting point of the individual polymers, the blend makes a transition to a rubbery state. The elastic modulus can change more than two orders of magnitude across the transition temperature (Ttr). As such, an SMP can formed into a desired shape of an endoprosthesis by heating it above the Ttr, fixing the SMP into the new shape, and cooling the material below Ttr. The SMP can then be arranged into a temporary shape by force, and then resume the memory shape once the force has been applied. Examples of SMPs include, but are not limited to, biodegradable polymers, such as oligo(ε-caprolactone)diol, oligo(ρ-dioxanone)diol, and non-biodegradable polymers such as, polynorborene, polyisoprene, styrene butadiene, polyurethane-based materials, vinyl acetate-polyester-based compounds, and others yet to be determined. As such, any SMP can be used in accordance with the present invention.
A closure element body having at least one layer made of an SMM or suitable superelastic material and other suitable layers can be compressed or restrained in its delivery configuration within the garage, and then deployed into the tissue so that it transforms to the trained shape and closes the fistula.
Also, the closure element can be comprised of a variety of known suitable deformable materials, including stainless steel, silver, platinum, tantalum, palladium, nickel, titanium, nitinol, nitinol having tertiary materials (U.S. 2005/0038500, which is incorporated herein by specific reference), niobium-tantalum alloy optionally doped with a tertiary material (U.S. 2004/0158309, 2007/0276488, and U.S. Ser. No. 12/070,646, which are each incorporated herein by specific reference) cobalt-chromium alloys, or other known biocompatible materials. Such biocompatible materials can include a suitable biocompatible polymer in addition to or in place of a suitable metal. The polymeric closure element can include biodegradable or bioabsorbable materials, which can be either plastically deformable or capable of being set in the deployed configuration.
In one embodiment, the closure element is made from a superelastic alloy such as nickel-titanium or nitinol, and includes a ternary element selected from the group of chemical elements consisting of iridium, platinum, gold, rhenium, tungsten, palladium, rhodium, tantalum, silver, ruthenium, or hafnium. The added ternary element improves the radiopacity of the nitinol closure element. The nitinol closure element has improved radiopacity yet retains its superelastic and shape memory behavior and further maintains a thin body thickness for high flexibility. For example, the closure element according to the present invention has 42.8 atomic percent nickel, 49.7 atomic percent titanium, and 7.5 atomic percent platinum.
In one embodiment, the closure element can be made at least in part of a high strength, low modulus metal alloy comprising Niobium, Tantalum, and at least one element selected from the group consisting of Zirconium, Tungsten, and Molybdenum. The closure element according to the present invention provide superior characteristics with regard to bio-compatibility, radio-opacity and MRI compatibility.
In one embodiment, the closure element can be made from or be coated with a biocompatible polymer. Examples of such biocompatible polymeric materials can include hydrophilic polymer, hydrophobic polymer biodegradable polymers, bioabsorbable polymers, and monomers thereof. Examples of such polymers can include nylons, poly(alpha-hydroxy esters), polylactic acids, polylactides, poly-L-lactide, poly-DL-lactide, poly-L-lactide-co-DL-lactide, polyglycolic acids, polyglycolide, polylactic-co-glycolic acids, polyglycolide-co-lactide, polyglycolide-co-DL-lactide, polyglycolide-co-L-lactide, polyanhydrides, polyanhydride-co-imides, polyesters, polyorthoesters, polycaprolactones, polyesters, polyanydrides, polyphosphazenes, polyester amides, polyester urethanes, polycarbonates, polytrimethylene carbonates, polyglycolide-co-trimethylene carbonates, poly(PBA-carbonates), polyfumarates, polypropylene fumarate, poly(p-dioxanone), polyhydroxyalkanoates, polyamino acids, poly-L-tyrosines, poly(beta-hydroxybutyrate), polyhydroxybutyrate-hydroxyvaleric acids, polyethylenes, polypropylenes, polyaliphatics, polyvinylalcohols, polyvinylacetates, hydrophobic/hydrophilic copolymers, alkylvinylalcohol copolymers, ethylenevinylalcohol copolymers (EVAL), propylenevinylalcohol copolymers, polyvinylpyrrolidone (PVP), combinations thereof, polymers having monomers thereof, or the like.
IV. Endoscope Closure Element Applier
In one embodiment, the medical device of the present invention is associated with or included as part of an endoscope. This includes the closure element applier and components there being coupled with an endoscope so as to be integrated therewith. Alternatively, the closure element applier medical device can be coupled to or operated with an endoscope such that the scope and closure element applier are separate, but couplable.
The medical device can be associated with or included with an endoscope, and the endoscope is delivered to the fistula to deliver the distal portion and closure element to the appropriate position. Many endoscopes include a working channel or lumen disposed in the center of the scope and extending from the proximal end to the distal end. Such an endoscope can be utilized and/or configured for receiving the closure element applier within the working channel so that it can be delivered to the fistula.
FIG. 11 is a cutaway side view illustrating an embodiment of an endoscope closure element applier600, which includes endoscope components and closure element components. As shown, the endoscope closure element applier600 can have atubular body602 with adistal end604. Thetubular body602 can include acamera lumen606 that contains acamera612 at thedistal end604 and can include other camera components commonly used in endoscopes. Thetubular body602 can also include alighting device lumen608 that contains alighting device614 at thedistal end604 and can include other lighting devices commonly used in endoscopes. Additionally, thetubular body602 can include a closureelement applier lumen610 that contains acarrier assembly300 containing aclosure element500. The closureelement applier lumen610 can open at thedistal end604 at adistal opening616. The distal opening can include an openingmember618 that can remain closed until theclosure element500 is ready to be deployed to close the fistula. The openingmember618 can optionally includeslits619 that allow for thecarrier assembly300 to pass therethrough so that theclosure element500 can be deployed. Also, thecarrier assembly300 can include the features and components as described herein.
In one embodiment, an endoscope includes components of a closure element applier so as to be a combination medical device having endoscopic components and closure element applier components. In such an embodiment, the endoscope portion can be utilized for delivery of the closure element applier portion to the fistula. The closure element applier can then be utilized as described herein for deploying a closure element into the tissue so as to close the fistula. Alternatively, a closure element applier includes components of an endoscope. For example, thelocator assembly200 can include thelocator tip200 having a portion (not shown) that functions as the optical portion of an endoscope. Accordingly, thetip200 anddistal portion210bof the locator assembly can be configured to operate as an endoscope, such as is shown inFIGS. 2A-2C.
In one embodiment, the medical device of the present invention is configured to be delivered through the lumen of an endoscope. In this embodiment, the endoscope is delivered to the fistula as endoscopes are normally utilized, and then the closure element applier is delivered through the lumen of the endoscope to the fistula such that the closure element can be deployed to close the fistula. For example, a guidewire can be delivered to the fistula using standard equipment and techniques, and the endoscope is delivered to the fistula by being passed over the guidewire, which is disposed within the working channel of the endoscope. When the distal end of the endoscope is appropriately positioned with respect to the fistula, the guidewire is retracted through the working channel and the closure element applier is traversed through the working channel so as to be positioned appropriately so that the closure element can be applied to close the fistula.
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. All references recited herein are incorporated herein by specific reference in their entirety.