US 20080097523 A1
A helical fastener having a high retentive surface area is provided and has a first end for enhancing penetration into tissue and a second end comprising a coil sectioning a diameter of the fastener for receiving longitudinal and rotational forces. The helical fasteners are attached to body tissue by a fastener applicator having a proximal portion comprising a handle and an actuator and an elongate distal portion for housing a plurality of fasteners. A transferring action of the actuator provides longitudinal and rotational movement of the fasteners out of the distal portion and into body tissue.
2. A surgical fastener comprising:
a continuous double helical coil having a distal end and a proximal end, the distal end terminating with dual points each for piercing tissue;
dual first helical coil sections adjacent the distal end each being associated with one of the dual points and each defining a gap therebetween; and
a connecting bar at the proximal end for engagement with an applicator for inserting the double helical coil into tissue to position.
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11. A surgical fastener comprising:
a plurality of helical spikes engageable with body tissue, each of the plurality of helical spikes having a helical central axis that forms a helix around the central axis of the surgical fastener, wherein each of the plurality of helical spikes further includes a circular cross-sectional configuration as viewed in a plane extending perpendicular to the helical central axis of each of the helical spikes and having a distal end portion with a tip that penetrates the body tissue as the surgical fastener is rotated relative to the body tissue; and
a connecting member located at a proximal end of the surgical fastener, the connecting member extending transverse to the central axis of the surgical fastener and attached to each of the helical spikes in the plurality of helical spikes, wherein the connecting member is engageable with the body tissue.
12. An applicator for applying fasteners comprising:
an elongate tubular member;
a rotator disposed in the tubular member;
a housing coupled to a proximal end of the tubular member;
a trigger pivotably disposed in the housing;
at least one fastener disposed in the tubular member, the at least one fastener having a helical configuration;
an actuation mechanism disposed in the housing, the actuation mechanism responsive to manipulation of the trigger for rotating the rotator relative to the tubular member and advancing the at least one fastener towards a distal end of the tubular member.
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This invention relates to surgical fasteners and their associated applicators, and more particularly, surgically fastening material to tissue.
Fasteners have been used surgically to eliminate the need for suturing, which is both time consuming and inconvenient. In many applications the surgeon can use a stapler apparatus, i.e., a fastener implanting device loaded with surgical fasteners to accomplish in a few seconds what would have taken many minutes to perform by suturing. This reduces blood loss and trauma to the patient.
Conventional surgical fasteners have been in the form of ordinary metal staples, which are bent by the delivery apparatus to hook together body tissue. Typically, conventional staples comprise a pair of legs joined together at one end by a crown. The crown may be a straight member connecting the legs or may form an apex. Moreover, the legs may extend substantially perpendicular from the crown or at some angle therefrom. Irrespective of the particular configuration, however, conventional staples are designed so that they may be deformed to hold body tissue.
Accordingly, the stapler applicators have conventionally embodied structure functioning to project the conventional staple into tissue as well as to deform the staple so that it is retained against the tissue. Generally speaking, typical applicators include an anvil cooperating with means to eject the conventional staple from the applicator. In some applications, access to the body tissue from two opposite directions is available and the anvil can operate to deform the legs of the staple after they have passed through the body tissue. In applications where access to the tissue is from only one direction, the anvil may deform the crown of the conventional staple so that its legs will project into the body tissue in a fashion so as to hold the staple against the tissue.
Since conventional staples require deformation and must cooperate with applicators having an anvil or other means to deform the staples, conventional applicators typically comprise complex structures and can be prohibitively expensive. Conventional applicators must embody structure functioning to not only eject the fasteners but to do so in a manner so that the fastener deforms properly and timely.
In some applications, conventional applicators must be equipped with structure functioning to move the anvil into and out of position so that when the fastener is ejected from the applicator, the anvil is properly positioned and once fastener deformation is complete, moves out of position, thereby allowing the process to be repeated. Moreover, the anvil must be formed into a proper configuration so that fastener deformation can be repeated accurately. Further, the force between the fastener and the anvil must be controlled so that repeated deformation is accomplished. The objectives of many inventions in this field have been to accomplish these goals by the simple manipulation of a single lever. It is to be appreciated, therefore, that the fastener applicators have become complex and expensive instruments.
Two part fasteners have also been conventionally utilized, where a barbed staple is used in conjunction with a retaining piece to hold the staple in place. Typically, the two part staple comprises a crown or backspan and two barbed prongs which are engaged and locked into a separate retainer piece. In use, the staple is pressed into the body tissue so that the barbs penetrate the tissue and emerge from the other side where they are then locked into the retainer piece. Retainers prevent the staple from working loose from the tissue. The two piece fasteners cannot be unlocked and are not removable.
Like other conventional applications, however, the two piece fasteners require the staple delivery apparatus to have access to both sides of the tissue. Thus, as with the other conventional applications, two piece fasteners are limited since they cannot be used where access to tissue is from one direction only.
In those situations where access to body tissues is limited to one direction, as in grafting procedures, deformable surgical fasteners have been conventionally employed. As mentioned previously, however, the applicators commonly used in these situations embody an anvil cooperating with a fastener to deform it and consequently, tend to be of a complex design.
Some advancements have been made in this area so that applicators functioning to attach grafts to tissue, for instance, are not required to embody an anvil and may, therefore, have a more simple design. In particular, it has been suggested in the art to employ fasteners with barbs, thereby eliminating the need for deforming the fastener. These fasteners are limited, however, since the path created in the graft and tissue by the barbs as the fastener is pressed into the graft and tissue may allow the fastener to loosen its grip or to entirely back out of engagement. Moreover, due to their sole reliance upon barbs to retain tissue, the barb fasteners are further limited in that they may not have a great enough retentive surface area for securely holding tissue in place.
To circumvent or overcome the problems and limitations associated with conventional fasteners and applicators, a simple applicator that dispenses a surgical fastener having high surface area for retentive contact with tissue and that can be delivered into body tissue from one direction may be employed. The present invention embodies these characteristics.
The invention includes a surgical fastener and an applicator used in delivering the fastener into body tissue. The fastener and applicator of the present invention may be used in a number of medical procedures including ligating tissue, hernia mesh repair, bladder neck suspension, and in conjunction with implant drug delivery systems or procedures involving positioning of surgical or implantable devices in a patient's body.
The preferred embodiment of the surgical fastener of the present invention is formed into the configuration of a continuous helical coil. The continuous helical coil is longitudinally collapsible and expandable. At the distal end of the helical fastener is a point for enhancing penetration into tissue. The proximal end of the helical fastener has a T-bar which sections the diameter of the fastener, thereby providing a surface for receiving and transmitting longitudinal and rotational forces so that the fastener may be driven into tissue by a corkscrew action. The pitch and length of the helical fastener may vary upon the application as can its diameter and configuration of the most proximal and distal coils comprising the fastener. Additionally, the material selection and fastener stiffness may be selected with a particular application in mind.
In another embodiment of the surgical fastener, the fastener comprises a double continuous helical coil that is also longitudinally collapsible and expandable and may embody various configurations depending upon the application. Moreover, the distal end of the double helical fastener comprises two points for enhancing penetration into tissue and its proximal end comprises a connector bar which connects the two helixes as well as sections the diameter of the double helical fastener. In yet another embodiment, the surgical fastener further comprises a pivot post extending through the center of the fastener and operating to provide the fastener with a stable pivot. In any of the embodiments, one or more barbs may be employed near the point to enhance anchoring characteristics.
A preferred embodiment of the fastener applicator of the present invention includes a proximal portion and a distal portion. The proximal portion is preferably fabricated to be a “reusable” component and the distal portion a “disposable” component. Alternatively, both the distal and proximal portion can be made disposable. The distal portion is elongate and embodies an outer tube housing an inner rotator, a lock clip/indicator and a load spring. The proximal portion includes a handle. In the preferred embodiment of the distal portion, a thread form comprising an interlock spring is provided within the outer tube. The rotator includes a structure running longitudinally along its length that functions to receive the T-bar or connector bar of the fastener and in this way, the rotator may hold a plurality of fasteners. The load spring applies a force against the lock clip/indicator operating to bias the plurality of springs distally within the outer tube and towards the nose piece. The thread form functions to engage the coils of the helical fasteners and when rotating the rotator, a fastener is driven from the distal end of the applicator. In other embodiments of the applicator, the distal end has various other structures functioning to engage the coils of the fastener and to drive them from the distal end of the applicator. In one other embodiment, the distal end comprises a nose piece protrusion for engaging the fastener.
In order to cause the rotator to rotate, the proximal portion of the applicator has a handle and an actuator cooperating with the rotator. In a preferred embodiment, the proximal portion of the applicator embodies a lever pivotally attached about a midpoint to the handle. A first end of the lever is configured to be gripped by hand and a second end is adapted to engage a nut driver. The nut driver travels along a helical lead screw which is connected to the rotator. When the lever is squeezed by hand the nut driver travels along the lead screw causing it to rotate, and through the connection of the lead screw to the rotator, the action of the lead screw causes the rotator to rotate.
Further, the lever comprises a midsection extension. Pivotally attached to the midsection extension of the lever is a spring loaded pawl adapted to releasably engage gear teeth formed in the interior of the handle. The spring loaded pawl prohibits the lever from backstroking until it has been completely depressed. Upon complete depression of the lever, the pawl clears the gear teeth and the spring, biasing the pawl, rotates the pawl away from the teeth, thereby allowing the lever to return to its undepressed condition.
In another embodiment of the proximal portion of the applicator, the lever is pivotally attached at a first end to the handle, the second end being adapted to engage the nut driver. Further, rather than embodying a spring loaded pawl, this alternate embodiment of the proximal portion includes a clutch assembly or releasable connection between the lead screw and rotator and cooperating means to prohibit the lever from backstroking until it has been completely depressed.
Other features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principals of the invention.
As is shown in the drawings, which are included for purposes of illustration and not by way of limitation, the invention is embodied in a continuous helical fastener and an applicator therefor. The helical fastener has a high retentive surface area and the applicator has a simple design and functions to dispense the helical fasteners, without substantially deforming the fasteners, into body tissue, access to which is from one direction only. Some conventional fasteners require deformation to hold tissue and are consequently limited since they require complex applicators to attach them into tissue. Other conventional fasteners lack high retentive surface area for securely holding tissue. Still other fastener/applicator systems require access to tissue from two directions in order to accomplish attaching a fastener to tissue. Thus, the helical fastener and applicator of the present invention provides a superior means to attach fasteners to tissue.
One embodiment of the present invention (
In a preferred embodiment, the fastener 10 is formed into the configuration of a continuous helix and may have a depth 16, a diameter 18 and a pitch 20 determined by the application. The continuous helix may be longitudinally collapsible and expandable. The cross-sectional profile of the continuous helix is substantially circular in the preferred embodiment but can be square, rectangular or triangular. In a particular application such as mesh anchoring for hernia repair, the pre-formed pitch can be 0.050 inches. However, the pre-formed pitch can vary from 0 to a maximum of approximately 3.0 times the coil diameter. In other embodiments, it is contemplated that the pitch 20 vary along the length of the fastener 10 so as to optimize the retaining force of the fastener 10. Moreover, since the continuous helical coil is preferably longitudinally collapsible and expandable, upon insertion into tissue, the final pitch 31 may be less than or greater than the pre-formed pitch. If the coil is made of rigid construction, as is also contemplated, pitch would be made substantially fixed. The diameter in the preferred embodiment may be 5 mm; however, designs ranging from 1 mm and up are contemplated. In practice, the depth 16 of the fastener 10 must be selected so that the extent of fastener penetration into tissue is sufficient to hold the fastener 10 in place.
Moreover, distal end 22 of the fastener 10 is to be configured such that a gap 23 exists between the most distal coil 27 (or first coil) of the fastener 10 and its adjacent coil. As may be appreciated from the preferred embodiment of
In the preferred embodiment, the distal end 22 of the helical fastener 10 terminates with a point 24. The point 24 may be sharp or blunt depending upon the tissue to which the fastener 10 will be affixed. Additionally, one or more barbs or a sharp point projecting in reverse direction to point 24 (not shown) can be added to fastener 10 near point 24 to enhance anchoring characteristics of the fastener. A proximal end 26 of the helical fastener 10 may comprise structure functioning to receive and transmit applied longitudinal forces. In the preferred embodiment, the most proximal coil is formed into a T-bar 33 that perpendicularly sections the diameter 18 of the fastener 10. In alternate embodiments, it is also contemplated that the most proximal coil section the diameter 18 non-perpendicularly or be formed into a spiral 35 existing in a single plane (See
Concerning the material of the helical fastener 10, it is contemplated in the preferred embodiment that the fastener be made from semi-stiff implantable wire, such as titanium, wound into a helical shape. In alternate embodiments, the helical fastener 10 may comprise plastic or absorbable materials. Examples of materials that can be used in constructing the helical fastener 10 include titanium, titanium alloys, stainless steel, nickel, chrome alloys and any other biocompatible implantable metals. Other options for materials are liquid crystal polymers, HDPE, polyglycolic acid, and polyglycolid hydroxgacetic acid. Further, it may also be desirable to coat the fastener, or a portion thereof, with a biocompatible lubricious material that provides for easier delivery of the fastener into tissue.
In another embodiment of the surgical fastener, the fastener 110 is formed into the configuration of a double helix (See
Regarding the proximal 118 and distal 120 ends of the double helical fastener 110, they comprise structure to drive the fastener into tissue as well as tissue piercing structures. The proximal end 118 has a connector bar 122 sectioning the diameter of the fastener that connects one helical coil to another and functions to receive and transmit longitudinal forces. The distal end 120 terminates with two points 124, 125 for piercing and facilitating the implantation of the fastener 110 into tissue.
As may be appreciated by comparing
In yet another embodiment of the surgical fastener, as shown in
The applicator 12 (
In more detail (See
It is also to be appreciated that load spring 42 applies a force through the lock clip indicator 40 to bias the plurality of fasteners distally. The lock clip/indicator 40 may comprise a simple washer sized and shaped to engage the fasteners and rotator 38 as well as to receive forces from the load spring 42. Additionally, lock/clip indicator 40 serves as a jam stop to prevent further actuation by rotator 38 upon discharge of all fasteners by mating with, or abutting against, structure comprising the terminal end 50 and preventing further rotation. Lock/indicator 40 can be made of a color (or shape) to serve as an empty indicator notifying the user that no more fasteners are available. Other embodiments of the indicator 40 may be utilized as long as they function to transmit forces to bias the fasteners distally. The load spring 42 is to be retained within the outer tube 36 and to have physical characteristics such that sufficient forces may be applied through a front end 43 to a last remaining fastener contained within the applicator 12. A back end (not shown) of the load spring 42 may be placed against any stationery structure within the outer tube 36, thereby providing a foundation against which the spring 42 may be compressed. In a preferred embodiment, the load spring 42 extends substantially the length of the distal portion 34.
In the preferred embodiment (
In another embodiment of the applicator 12 (
In other embodiments of the applicator 12, the distal portion embodies other structure or thread forms functioning to engage the surgical fasteners and guide them out of the applicator and into tissue (See
In order to eject surgical fasteners from the distal portion 34, the actuator 32 functions to turn the rotator 38. As the rotator turns, the distal end 22 of a fastener is threaded out of the terminal end 46 of the applicator 12 (see
In the preferred embodiment of the proximal portion 28 of the applicator 12 (See
The nut driver 62 of the applicator 12 travels upon a high helix lead screw 64 which is rotatably mounted within the proximal portion 28. In the preferred embodiment, a longitudinal axis of the high helix lead screw 64 is coaxial with the longitudinal axis 52 extending through the distal portion 34 of the applicator 12. Upon manipulation of the lever 54, the nut driver 62 travels along the lead screw 64 causing it to rotate through a connection of the lead screw 64 to the rotator 38, the action of the lead screw causes the rotator to rotate. The lead screw 64 may be connected to the rotator 38 by any conventional means. For instance, the lead screw 64 can have an internal bore receiving and engaging an end of the rotator 38. Further, the length of travel of the nut driver 62 along the lead screw 64 is chosen such that it causes the rotator to rotate a predetermined number of times so that a single helical fastener 10 is ejected from the applicator 12.
Additionally, in the preferred embodiment, the lever further comprises a midsection extension 66. Pivotally attached to the midsection extension 66 of the lever 54 is contemplated to be a spring loaded pawl 68 adapted to releasably engage gear teeth 70 formed in the interior of the handle 30. Spring loaded pawl 68 is configured to prohibit the lever 54 from backstroking until it has been completely depressed. Upon complete depression of the lever 54, the pawl 68 clears the gear teeth 70 and the spring biasing the pawl 68 rotates the pawl 68 away from the teeth 70, thereby allowing the lever 54 to return to its undepressed condition.
In operation, upon complete depression of the lever 54, the nut driver 62 travels a pre-determined distance along the lead screw 64, causing the rotator 38 to rotate a pre-determined number of revolutions corresponding to a number of turns of a particular helical fastener 10. As the rotator 38 rotates, the fasteners retained by the rotator also rotate and the coils of the most distal fastener are threaded out of the terminal end 46 of the applicator 12 and into tissue. Moreover, where the lever 54 is only partially depressed, the spring loaded pawl 68 operates to hold the lever 54 stationery and will continue to function to hold the lever 54 stationery until the lever 54 has been completely depressed. In this way, the delivery of fasteners into body tissue is controlled so that only a single fastener may be completely ejected out of the applicator 12 and pressed into body tissue at a time.
In the preferred embodiment, the proximal portion 28 is fabricated to have a reusable handle that can be re-sterilized, and the distal portion is made disposable. Thus, upon discharge of all the fasteners 10 from distal portion 34, the distal portion would be discarded and replaced. The handle could be reused up to a limited number of procedures.
In another embodiment of the proximal portion 328, of the applicator 312 (
The nut driver 362 of the applicator 312 travels along a high helix lead screw 364 which is rotatably mounted within the proximal portion 328. Upon manipulation of the lever 354, the nut driver travels along the lead screw 364 causing it to rotate and, through a clutch assembly or a releasable connection of the lead screw 364 to the rotator 38, the action of the lead screw causes the rotator to rotate.
Further, the lever 354, has a mid-section extension 366 that cooperates with a spring biased latch pawl mechanism 368 fixed to the handle adapted to releasably engage teeth 370 formed on the mid-section extension 366. The spring biased latch pawl is configured to prohibit the lever 354 from backstroking until it has been completely depressed. Upon complete depression of the lever 354, the latch pawl 368 clears the mid-section teeth 370 and the spring biased latch pawl 368 rotates away from the teeth, thereby allowing the lever 354 to return to its undepressed condition.
As stated, there is a releasable connection between the lead screw 364 and the rotator. The releasable connection provides the applicator with means to disengage the distal portion of the applicator from the proximal portion. In this way, the proximal portion can be re-used with various different designs of the proximal portion. Further, while the lever 354 is being depressed, the clutch assembly or releasable connection functions to transfer the rotation of the lead screw 364 to the rotator 38, thereby causing the rotator to rotate. Additionally, upon complete depression of the lever, the clutch assembly operates to allow relative motion of the lead screw 364 and the rotator.
One such releasable connection contemplated is a conventional ratchet mechanism. As shown in
In this embodiment, upon complete depression of the lever 354, the nut driver 362 travels a pre-determined distance along the lead screw 364, causing the rotator 38 to rotate a pre-determined number of revolutions. As the rotator 38 rotates, the fasteners retained by the rotator also rotate and the coils of the most distal fasteners are threaded out of the applicator and into the tissue. At this point, the latch pawl mechanism 368 disengages from the teeth 370 and the lever 354 is returned to its undepressed position by spring 357. As with the previous embodiment of the proximal portion 28, the proximal portion of this embodiment functions to allow only a single fastener to be completely ejected from the applicator and be pressed into body tissue at a time.
In other embodiments, means to cause the rotator to rotate may comprise a single knob connected to a rotator which can be turned by hand. Additionally, the revolving means may include a rack and gear structure or a set of beveled gears. Further, instead of comprising a groove, the rotator may be internally threaded, wherein the threaded portions function to house as well as advance the helical fasteners 10. Irrespective of the means or structure employed, however, it is contemplated that the number of revolutions of the rotator be set to a pre-determined parameter so that the delivery of helical fasteners to tissue may be controlled.
From the foregoing, it will be appreciated that the helical fastener in applicator of the present invention functions to securely attach a fastener with high retentive surface area to tissue from one direction through the utilization of an applicator having a simple design. It is also to be appreciated that the present invention may be utilized in a number of applications including ligating tissue, hernia mesh repair, bladder neck suspension, and in conjunction with implant drug delivery systems or procedures involving positioning of surgical or implantable devices in patient.
While several particular forms of the invention have been illustrated and described, it will also be apparent that various modifications can be made without departing from the spirit and scope of the invention.
Thus, it should be understood that various changes in form, detail and application of the present invention may be made without departing from the spirit and scope of this invention.