Patent Description:
Spinal surgery in the United States is increasing in volume and complexity. Movements and trends to allow surgery with decreased morbidity and faster healing time are becoming more popular and are collectively known as minimally invasive procedures.

Spinal surgery often involves working around the spinal cord and nerves which are contained in spinal fluid. The fluid is held in place by tissue called the dura, which creates the thecal sac allowing the tissues to "float" within it. The dura can be torn as the result of injury.

Repair of these injuries is commonly done with a direct repair of this tissue by sewing the two sides of the torn dura back together. However these procedures are limited by the fact the nerves within the sac push up through the tear, complicating closure and increasing the likelihood of nerve damage. Additionally, the tear can be located in a position where passage of a needle is difficult, or where the suture line or circumference of a repair or knot strangulates one or more nerves.

Current devices, suture types, and needles are often too large for working within the limited spaces required for minimally invasive procedures. This results in repair including a step of increasing the size of the exposed area of tissue to allow for adequate closure. This defeats the purpose of a minimally invasive procedure.

There is a continuing need for improved devices and methods allowing for closure of a dural tear while protecting nerves and the spinal cord from being included in a suture and knot or otherwise damaged during closure. Such devices and methods are described herein.

<CIT> discloses a suture passing forceps including an axially elongated support shaft (<NUM>), and a first suture holder (<NUM>) for removably holding a needled suture (<NUM>) and a second suture holder (<NUM>) for capturing the needled suture. The first suture holder includes a suture inlet (<NUM>) through which at least part of the suture can be passed. The first suture holder or the second suture holder is an actuatable member which pivots toward an operating position to capture the needled suture in the second suture holder and pivots away from the operating position to remove the suture from the first suture holder. The suture inlet in the suture holder enables complete removal of the suture from the suture holder when the actuatable member and the needled suture move away from the operating position. The second suture holder includes a holding region defined by a contoured surface permitting the needled suture to slide within the holding region.

<CIT> discloses a device for suturing having a grip end and a working end. The grip end includes a stationary handle and a pivoting handle. The working end includes an upper jaw and a lower jaw that are squeezed together, when the pivoting handle is squeezed to the stationary handle. The jaws are configured to accommodate a needle. Each of the upper jaw and the lower jaw include mechanics for retaining and releasing the needle and the needle can have corresponding geometry, in order to ensure that the needle is held securely. A toggle lever actuates the mechanics to switch the needle from the upper jaw to the lower jaw, or vice versa, when the jaws are in the closed position. The device can be used to suture tissue, such as fascia, during surgery to close an incision, or in the field to close a wound.

<CIT> discloses a needle holder for guiding a surgical needle having a suture attached to the needle, in which the surgical needle is transferred from a first shaft to a second shaft, comprising a needle stand formed on the first shaft and a needle receiver formed on the second shaft, receiving the needle made upright at the needle stand. Further, the needle holder comprises a guide passage formed on the first shaft for guiding the suture attached to the needle from the needle stand in a prescribed direction to at least the vicinity of the needle stand, the guide passage having a surface that has no edge damaging the suture in a cross direction with respect to the direction of the tension exerted to the suture.

The invention is directed to a dural repair device as defined in claim <NUM>. Specific embodiments are set forth in the dependent claims.

Additional aspects and advantages of the invention will be apparent in view of the description below.

The embodiments set forth in the drawings are illustrative and exemplary in nature and not intended to limit the invention defined by the claims. The following detailed description of the illustrative embodiments can be understood when read in conjunction with the following drawings, in which:.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments of this invention belong. The terminology used herein is for describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification and appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Additionally, the disclosure of any ranges in the specification and claims are to be understood as including the range itself and also anything subsumed therein, as well as endpoints. Numerical ranges as used herein are intended to include every number and subset of numbers within that range, whether specifically disclosed or not. Unless otherwise indicated, the numerical properties set forth in the specification and claims are approximations that can vary depending on the desired properties sought to be obtained in embodiments of the present invention. Notwithstanding that numerical ranges and parameters setting forth the broad scope of embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical values, however, inherently contain certain errors necessarily resulting from error found in their respective measurements.

The dura and surrounding tissue structures are known in the art. Such structures are detailed in the text The Human Brain and Spinal Cord: Functional Neuroanatomy and Dissection Guide by Lennart Heimer. Such structures are detailed in Clinical Anatomy of the Spine, Spinal Cord, and ANS, by Gregory D. Cramer DC ad Susan A.

The term "platform" as used herein, unless otherwise specified, refers to a portion of the inner arm useable for putting pressure on a portion of a nerve, rootlet, or spinal cord. In specific embodiments the pressure is aimed to result in movement of a part of a nerve, rootlet, and/or spinal cord. In specific embodiments the platform is also useable for putting pressure on tissue surrounding the nerve, rootlet, or spinal cord. In specific embodiments the platform is also useable for putting pressure on the nerve, rootlet, and/or spinal cord and/or putting pressure on tissue surrounding the nerve, rootlet, or spinal cord without causing damage to the material pressed.

The term "heel" as used herein, unless otherwise specified, refers to the place at which the platform meets the portion of the inner arm running essentially longitudinally back toward the coupling at the central region of the device. In specific embodiments the heel includes a sharp or otherwise angled region as one moves from the platform to the essentially longitudinally running section of the inner arm. In specific embodiments the heel and platform form a continuous curve.

The term "handle" as used herein, unless otherwise specified, refers to a section of the device that can be used to move the inner and/or outer arm. In specific, non-limiting embodiments, the device has a top section comprising two opposing upper arms that together act as an embodiment of the handle. Various additional handle embodiments are described herein.

The term "activate" as used herein in reference to the handle, unless otherwise specified, refers to mechanically or electronically causing movement of at least a portion of the handle, directly or indirectly, so as to move the inner and/or outer arm.

<FIG> illustrates a dural repair device <NUM>. The device has a top section <NUM> with an example length A-A, a bottom section <NUM> with an example length B-B, and the bottom section <NUM> has an example width C-C when the dural repair device is in an open position. The top section <NUM> comprises two opposing upper arms, <NUM> and <NUM>, that together can act as an embodiment of the handle and which is squeezable by a single hand such that arms <NUM> and <NUM> move toward one another and each moves toward a longitudinal midline E-E of the device <NUM>. The bottom section <NUM> comprises two opposing arms, an inner arm <NUM> and an outer arm <NUM>. The device <NUM> can have a coupling <NUM> positioned substantially between the top section <NUM> and bottom section <NUM>. The inner arm <NUM> has a heel <NUM>, a platform <NUM> with an example length D-D, a tip <NUM>, and an end opening <NUM>. In specific embodiments the platform <NUM> can be formed of a straight line. In specific embodiments, the angle between the platform <NUM> and the inner arm <NUM> is about <NUM> degrees, or from about <NUM> degrees to about <NUM> degrees, or from about <NUM> degrees to about <NUM> degrees, or from about <NUM> degrees to about <NUM> degrees. The outer arm <NUM> has a bottom surface <NUM> and an end opening <NUM>. According to the invention, the outer arm <NUM> comprises a mechanism M for holding a needle <NUM> therewithin and the needle <NUM> can be coupled to suture <NUM>. Specific embodiments of the mechanism M can include a direct attachment to an inner wall of the outer arm <NUM> or attachment to an extension coupled to the inner wall of the inner arm. For example, the attachment could include adhesives, or attachment via a breakable clip, or the needle <NUM> could be hooked via a loop or other attachment to a protrusion or protrusions extending up from the inner wall of the outer arm <NUM>. The protrusion or protrusions can be at any angle or a series of angles from the inner wall of the outer arm <NUM>, such as from about <NUM> to about <NUM> degrees. The protrusions can extend from the inner top, inner bottom, or inner side of the outer arm, or in between. <FIG> provides non-limiting examples of mechanism M, and various other mechanisms M are described and illustrated herein.

According to the invention, the inner arm <NUM> comprises the tip <NUM> extending out toward the longitudinal midline E-E of the device <NUM> farther than any portion of the platform <NUM> or heel <NUM>. According to the invention, the tip <NUM>, platform <NUM>, or heel <NUM> have at least one curved portion that is slidable under an edge of dura and is/are configured to push rootlets away from the device <NUM>. In specific embodiments the platform <NUM> comprises a continuous curve.

In specific embodiments, the length of the platform <NUM> is less than <NUM>, or less than about <NUM>, or less than about <NUM>, or less than about <NUM>. In specific embodiments, the length of the platform <NUM> is from about <NUM> to about <NUM>, or from about <NUM> to about <NUM>, or from about <NUM> to about <NUM>.

In specific embodiments, a maximum distance between the outer arm <NUM> and inner arm <NUM> end openings (<NUM>, <NUM>) is less than about <NUM>, or less than about <NUM>, or less than about <NUM>. In specific embodiments the maximum distance between the outer arm <NUM> and inner arm <NUM> end openings (<NUM>, <NUM>) is from about <NUM> to about <NUM>, or from about <NUM> to about <NUM>.

<FIG> illustrates the dural repair device <NUM> of <FIG> in a closed position. When the two opposing upper arms <NUM> and <NUM> (not shown in <FIG>) are moved toward one another, the two opposing arms, inner arm <NUM> and outer arm <NUM> respectively, move toward one another, and toward the longitudinal midline E-E of the device. The opposing upper arms <NUM> and <NUM> can be moved toward each other such that inner arm <NUM> and outer arm <NUM> are moved so as to couple. The needle <NUM> can be contained within the outer arm <NUM>. <FIG>, for completeness, also depicts the coupling <NUM>, heel <NUM> and platform <NUM> of the inner arm <NUM>, the bottom surface <NUM> of the outer arm <NUM>, the needle <NUM>, and the suture <NUM>.

<FIG> illustrates the dural repair device <NUM> where the upper arms <NUM> and <NUM> (not shown in <FIG>) were moved toward one another such that inner arm <NUM> and the outer arm <NUM> coupled, and the needle <NUM> was passed from outer arm <NUM> inner arm <NUM>. In specific embodiments upon handle activation the needle <NUM> transfers, and more specifically, the needle <NUM> is initially in specific embodiments held completely within the outer arm <NUM>, and after the transfer of the needle <NUM> to the inner arm <NUM> the needle <NUM> is held completely within the inner arm <NUM>, and no portion of the needle <NUM> passes either of the arm (<NUM>, <NUM>) openings (<NUM>, <NUM>) until after the arms (<NUM>, <NUM>) couple. According to the invention, the inner arm <NUM> comprises a mechanism (not shown in <FIG>) for catching the needle <NUM>. This mechanism can be a depression within a wall of the inner arm <NUM>. The depression can be a groove or series of grooves. The mechanism can include a depression matching at least part of the shape of the needle <NUM>. The mechanism can as also be a hole or holes through the inner arm <NUM>. The mechanism can also be a catch or series of catches extending up from the inner wall of the inner arm and the same or mixed angles. An extending catch can be at an angle such as from about <NUM> to about <NUM> degrees in relation to the inner surface of the inner arm <NUM> (such as from about <NUM> to about <NUM>, and/or from about <NUM> to about <NUM>, and/or from about <NUM> to about <NUM> degrees). An extending catch can also have a loop or adhesive for catching the needle <NUM>. The extending catch can be formed of a ring extending out from the inner arm <NUM>, or can be formed of a magnet. <FIG>, for completeness, also depicts the coupling <NUM>, heel <NUM>, platform <NUM>, and tip <NUM> of the inner arm <NUM>, the bottom surface <NUM> of the outer arm <NUM>, and the suture <NUM>.

According to the invention, the outer arm <NUM> and the inner arm <NUM> are formed of a single piece. In other examples not forming part of the invention, the arms (<NUM>, <NUM>) are formed separately. In either case the coupling <NUM> can be used to draw together a single piece of metal used to form both arms (<NUM>, <NUM>) and/ or can be used to form a substantially figure-eight formation where the metal overlaps itself (<NUM>, <NUM>). The handle can comprise a shape-memory alloy such as nickel-titanium (NiTi). The coupling <NUM> can include slots for the arms (<NUM>, <NUM>) and/or handle <NUM> portions to slide through. The coupling <NUM> can include a ratchet mechanism therewithin or coupled thereto, such that squeezing of the handle leads to locking in of arms (<NUM>, <NUM>) at multiple opening positions; in such a case a mechanism for ratchet release can include a side-button on the device <NUM>, or a simple pressure mechanism such that upon reaching the closed position where the arms (<NUM>, <NUM>) couple, a further forcing together of the upper arms <NUM> and <NUM> by squeezing the handle releases the ratchet to the open position.

Embodiments of the device outlined herein show surprising effectiveness in results for methods of repairing injuries to the dura. Current technologies tend to lead to additional injuries or require cerebrospinal fluid drainage for localized repair. Methods described herein can be used when the dura has been damaged due to direct injury by instruments and/or during removal of attached tissues including scar tissue, a cyst, a disc, and/or ligamentum flavum. <FIG> illustrates a region for repair of the dura. Shown is the dura <NUM> and a tear <NUM> of the dura <NUM>. Also shown for context is a facet joint <NUM>, and spinous process <NUM>. As indicated, an example distance is shown as F-F. In specific embodiments F-F is less than <NUM> in length.

Example <NUM>: Device Loading. In specific embodiments the entire device <NUM> is preloaded with <NUM>-OProlene® type suture <NUM> and needle <NUM>. The needle <NUM> and platform <NUM> meet when the handle is squeezed or the needle <NUM> may be free and then moved by separate forcep or caught by the catch of the inner arm <NUM>. At least a portion of the inner arm <NUM> slides under the edge of the dura <NUM> pushing rootlets <NUM> and has a groove that matches the needle <NUM> and catches or accepts it. The handle is squeezed and two upper arms, <NUM> and <NUM>, come together. The needle <NUM> is protected and rootlets <NUM> can't be caught in a portion of the needle <NUM> and/or suture <NUM> during repair.

Sutures for methods and devices as described herein can include one or a combination or combinations of monofilament, multifilament synthetic, biological, absorbable, and/or non-bioabsorbable sutures. Non-limiting examples of monofilament sutures include Monocryl®, Ethilon®, Prolene®, and/or PDS® II polydioxanone. Non-limiting examples of multifilament sutures include Vicryl®, Silk sutureVicryl Plus®, Vicryl Rapide®, Silk suture such as PERMA-HAND® Silk Suture, Ethibond®, and/or Mersilene®. Non-limiting examples of synthetic sutures include Monocryl®, Mersilene®, Ethilon®, Vicryl®, Vicryl Plus®, Vicryl Rapide®, Ethibond®, Prolene®, and/or PDS ®II. A non-limiting example of a biological is silk suture. Non-limiting examples of absorbable sutures include Monocryl®, Vicryl®, Vicryl Plus®, Vicryl Rapide®, and/or PDS II. Non-limiting examples of non-absorbable sutures include Mersilene®, Ethilon®, Silk suture®, Ethibond®, and/or Prolene. Non-limiting examples of suture material can include one or more of: stainless steel, polyester, polypropylene, nylon, and/or cotton. Needles use herein can be curved or straight.

The device <NUM> handle or other portions can be made partially or entirely out or a metal or metals or a composite of materials. In a specific example, part or all of the device comprises a shape-memory material. In a specific example, part or all of the device comprises one or more of copper-aluminium-nickel, nickel-titanium (NiTi), zinc, copper, gold and/or iron.

Example <NUM>: Dura is partially torn, but there is no leak of cerebrospinal fluid from the spinal canal. Rootlets float and are next to site of the repair. If the fluid is drained then they would sink and repair would be easier but rather than complete the tear to then fix the tear, the methods provided herein can be used to fix the original, partial tear. The methods provided herein can fix the tear wherein cerebrospinal fluid is not drained during the repair procedure. At least a portion of the inner arm <NUM>, such as the platform <NUM>, can be used to safely push a nerve, rootlet, or portion of the spinal cord away from the device such that a suture <NUM> or needle <NUM> does not touch or otherwise damage the nerve, rootlet, or portion of the spinal cord, even when any of these are floating in cerebrospinal fluid.

This is illustrated in <FIG>, which illustrates the dura <NUM>, tear <NUM>, rootlets <NUM>, and space containing cerebrospinal fluid <NUM>. <FIG> illustrates placement of the device <NUM> such that the inner arm <NUM> and outer arm <NUM> are on opposite sides of the dura <NUM>, and there is a dural tear <NUM> with no leak of cerebrospinal fluid. In <FIG> the platform <NUM> is used to move floating rootlets <NUM> away from the device <NUM> so as to protect the rootlets <NUM> from the needle <NUM>. <FIG> also illustrates the space containing cerebrospinal fluid <NUM> and the heel <NUM> of the inner arm <NUM>. Though in <FIG> the needle <NUM> is shown as partially exposed from the end opening <NUM> of the outer arm <NUM>, various embodiments contemplate the needle <NUM> being held fully within the outer arm <NUM>, partially within the outer arm <NUM>, and/or beyond the outer arm <NUM> end opening <NUM>. More specifically, the needle <NUM> can be held within the outer arm <NUM> so as to prevent any interaction with rootlets <NUM>; alternatively, the needle <NUM> can be held so that it is partially exposed, with the needle <NUM> held such that a portion is within the outer arm <NUM> and a portion is exposed toward the space containing cerebrospinal fluid <NUM>. Alternatively, an embodiment could include exterior placement of the needle <NUM> in relation to the outer arm <NUM> end opening <NUM>. The needle <NUM> can be, in specific embodiments, held by jaws either within, partially within, or outside of the outer arm <NUM>.

<FIG> shows a continuation of the repair of the tear <NUM> of the dura <NUM> of <FIG>, where the rootlets <NUM> (not shown in <FIG>) have been successfully pushed by the platform <NUM> from the area within the space containing cerebrospinal fluid <NUM>, and needle <NUM> can be passed from the outer arm <NUM> to the inner arm. As shown in <FIG>, the platform <NUM> can be multisegmented so as to allow a platform shape with one or more than one curves, or a specific shape as required for a given surgery. <FIG> illustrates continued repair of the tear <NUM> of the dura <NUM>. Once the needle <NUM> is caught by the inner arm <NUM>, the inner <NUM> and outer <NUM> arms are separated as the handle is released, the thread can be pulled through the dura <NUM>. As this occurs, the rootlets <NUM> can float in the space containing cerebrospinal fluid <NUM> back toward the dura <NUM> and the site of repair, without being damaged. The process of suturing can then be repeated until complete closure of the dura <NUM> is achieved. The outer arm <NUM> is configured such that a needle <NUM> can be manually loaded, or it can be set to be preloaded with multiple needles <NUM> and can be configured so that one needle <NUM> is released from within the outer arm <NUM> so as to be held for use once a needle <NUM> has been used. The inner arm <NUM> can be configured for manual or electronic removal of the needle <NUM> from the catch. In specific embodiments one needle <NUM> is reused and manually or mechanically moved back to the outer arm <NUM> for reuse.

Example <NUM>: Repairing dural tears at the edge of dissection when the needle is too big to make a throw without catching rootlets. Methods described herein can be used when torn dura comprises a tear located at a bony side wall of the spinal canal. This is shown in <FIG> which illustrates the tear <NUM> in the dura <NUM>, the rootlets <NUM>, the space containing cerebrospinal fluid <NUM>, and bony side wall <NUM> of the spinal canal. With current technologies there would be a risk of damage due to a needle throw catching rootlets. With currently outlined embodiments, the rootlets would be protected, and in some cases no cerebrospinal drainage would be required. It is contemplated that during repairs described herein, cerebrospinal drainage, or a removal of a small quantity of cerebrospinal fluid could be performed, however other embodiments are envisioned without removal of the fluid; in either case less fluid removal would be required than versus methods of current technologies. Upon repair of the dura, methods described herein can also include additional repair steps such as glues or staples.

Example <NUM>: Mechanisms for holding the needle. <FIG> outlined various mechanisms M for holding the needle. <FIG> illustrates various additional mechanism M embodiments. More specifically, <FIG> illustrates the outer arm <NUM> and example embodiments <NUM>-<NUM> of mechanisms M for holding the needle <NUM>. The needle <NUM> can be held at or beyond the end opening <NUM> of the outer arm <NUM> as illustrated in embodiment <NUM>, or can be held directly against or be otherwise attached to an inner wall of the outer arm <NUM> as shown in embodiments <NUM> and <NUM>. The needle can slide into a hole or notch in the inner wall of the outer arm <NUM>. The needles can be held by or an attachment or an extension coupled to the inner wall of the inner arm <NUM>. The needle <NUM> can be held by jaws <NUM> as shown in embodiments <NUM> and <NUM>. The jaws <NUM> can extend partially or fully out from the end opening <NUM> of the outer arm as in embodiment <NUM>, or the jaws <NUM> and/or part or all of the needle <NUM> can be held partially or fully within the outer arm <NUM> as in embodiment <NUM>. In specific embodiments the surfaces of the jaws <NUM> facing the needle <NUM> are smooth and a friction fit holds the needle <NUM>. In other embodiments the jaws <NUM> have ridges or teeth for holding the needle <NUM>. In other embodiments the needle <NUM> is placeable between the jaws <NUM> which are held together with spring force. In specific embodiments the jaws <NUM> can be set to various needle sizes, such as <NUM>, <NUM>, <NUM>, <NUM> or <NUM> sizes, or from about <NUM> to about <NUM> sizes, and in specific embodiments the jaws <NUM> can be set to various position and locked in place to act as a clamp. In specific embodiments the force of the jaws <NUM> against the needle <NUM>, when acting as a clamp, can be set for a tighter fit against the needle <NUM>, as with a turning of a screw or electronic push of a button thereby moving the jaws <NUM> electronically; in other cases the settings are manually configured.

Claim 1:
A dural repair device (<NUM>) operable with a single hand, the device (<NUM>) comprising:
a top section (<NUM>) comprising a handle, wherein the handle comprises opposable arms (<NUM>, <NUM>) squeezable by a single hand to move the opposable arms (<NUM>, <NUM>) towards one another and toward a longitudinal midline (E-E) of the dural repair device (<NUM>);
a bottom section (<NUM>) comprising:
an outer arm (<NUM>) comprising an end opening (<NUM>) and a mechanism (M) for holding a needle (<NUM>) at the end opening (<NUM>); and
an inner arm (<NUM>) comprising, at its distal end, a heel (<NUM>), a platform (<NUM>), and an end opening (<NUM>), with the platform (<NUM>) located between the heel (<NUM>) and the end opening (<NUM>) and with the heel (<NUM>), the platform (<NUM>) and the end opening (<NUM>) extending toward the outer arm (<NUM>), and, wherein the inner arm (<NUM>) is provided at the end opening (<NUM>) with a mechanism for catching the needle (<NUM>) from the outer arm (<NUM>),
wherein the handle is activatable by squeezing with a single hand to cause the inner and outer arms (<NUM>, <NUM>) to move towards one another and couple, and the needle (<NUM>) held in the mechanism (M) in the outer arm (<NUM>) to be caught by the mechanism for catching the needle (<NUM>) provided at the end opening (<NUM>) of the inner arm (<NUM>), wherein
the handle is releasable to move the inner and outer arms (<NUM>, <NUM>) away from one another and to transfer the needle (<NUM>) from the outer arm (<NUM>) to the mechanism for catching the needle (<NUM>) at the end opening (<NUM>) of the inner arm (<NUM>);
the inner arm (<NUM>) further comprises a tip (<NUM>) extending out toward the longitudinal midline (E-E) of the dural repair device (<NUM>) beyond any portion of the platform (<NUM>) or heel (<NUM>), and wherein the tip (<NUM>), platform (<NUM>), or heel (<NUM>) have at least one curved portion that is slidable under an edge of dura so as to push rootlets away from the needle (<NUM>); and characterised in that
the handle, the outer arm (<NUM>) and the inner arm (<NUM>) are formed of a single piece.