Device for atrial appendage exclusion

A surgical applicator for a fastener, the surgical applicator comprising: a handle; a trigger movable relative to the handle between an initial position, an actuated position, and an intermediate position between the initial position and the actuated position; and a lockout mechanism movable relative to the trigger between a locked position and an unlocked position, the lockout mechanism operatively arranged to: lock the trigger in the intermediate position when the trigger is moved from the initial position toward the actuated position; and permit movement of the trigger from the intermediate position toward the initial position or the actuated position when the lockout mechanism is moved from the locked position to the unlocked position.

BACKGROUND OF THE INVENTION

Field of the Invention

The present disclosure pertains broadly to the field of fasteners and/or applicators. More specifically, the disclosure relates to surgical applicators of implants and/or fasteners, including but not limited to sterilized fasteners such as staples.

Background of the Invention

Atrial fibrillation is a relatively common condition characterized by a very rapid heartbeat of the left and right atrium. While atrial fibrillation is not normally fatal itself, it has been associated with an increased risk of stroke. It is believed that the rapid heartbeat causes blood to pool in the left atrial appendage (LAA) which causes emboli that are released into the left atrium from where they can enter the cerebral vasculature, thus causing a stroke. In addition to stroke, the emboli can enter coronary circulation, potentially causing myocardial infarction, or can enter peripheral circulation, potentially causing peripheral vascular disease.

The risk of stroke in patients suffering from atrial fibrillation can be reduced in a variety of ways. For example, blood thinning drugs can be used to reduce the risk of clot formation. The use of blood thinners, however, is contraindicated in patients at risk of bleeding disorders. More aggressive treatment protocols have been proposed which involve closing the LAA. Closure and excision may be performed in open surgical procedures, typically requiring the patient to be placed on by-pass and the chest to be opened through the sternum. Alternatively, thoracoscopic and other less invasive procedures have been proposed. The tools are used to ablate or fuse the LAA from the inside using energy, adhesives, or the like.

In some examples, a compliant closure structure may be used for closing the LAA. Such compliant structure may have an elastomeric body having a pair of opposed legs which may be arranged in an oval or a U-shaped configuration to define an opening therebetween. By placing the opening between the legs over the LAA and aligning it with the base of the LAA, the compliant closure structure may be closed to provide the desired sealing of the LAA. To hold the compliant closure structure closed, a number of discrete, axially spaced-apart tissue penetrating fasteners are arranged along the lengths of each of the legs. By compressing the legs together to press-fit the closure devices, the compliant closure structure may be closed to provide a compliant seal which effectively isolates the LAA.

The compliant closure structure is closed using a hand-operated delivery tool having jaws which can be inserted into the legs of the closure structure and actuated to close the jaws in the legs over the LAA. The jaws further include comb studs which engage and press fit the closure devices in order to hold the compliant closure structure in its closed, sealing configuration. The studs are intended to be retracted to allow the delivery tool to be removed.

Existing delivery tools have certain shortcomings. For example, the actuation of the jaws and retraction of the comb studs can be performed out of order, increasing the risk that the delivery of the compliant structure will fail. Additionally, existing delivery tools do not allow for repeated “previewing” of the placement of the compliant closure structure on the LAA without closing the tissue penetrating fasteners. Moreover, positioning and orientation of the delivery tool can be difficult, particularly when the tool is introduced through an intercostal penetration to access the LAA.

SUMMARY OF THE INVENTION

For these reasons, it would be desirable to provide improved delivery tools for use with the compliant closure devices for sealing the LAA. It would be further desirable if the delivery tools and methods of their use were compatible with the delivery of other tissue closure devices and for procedures in addition to closure of the LAA.

According to some non-limiting examples, a surgical applicator for a fastener may include a handle, a trigger movable relative to the handle between an initial position, an actuated position, and an intermediate position between the initial position and the actuated position, and a lockout mechanism movable relative to the trigger between a locked position and an unlocked position. The lockout mechanism may be operatively arranged to: lock the trigger in the intermediate position when the trigger is moved from the initial position toward the actuated position, and permit movement of the trigger from the intermediate position toward the initial position or the actuated position when the lockout mechanism is moved from the locked position to the unlocked position.

According to some non-limiting examples, the lockout mechanism may be further operatively arranged to permit movement of the trigger from the initial position to the actuated position when the lockout mechanism is moved from the locked position to the unlocked position prior to movement of the trigger from the initial position. The trigger may be movable relative to the handle from the initial position with application of a compressive force on the trigger in a direction toward the handle. The trigger may have a distal side opposite a proximal side facing the handle, and at least a portion of the lockout mechanism may be positioned on the distal side of the trigger.

According to some non-limiting examples, the lockout mechanism may have a release button connected to the trigger, the release button being movable between a first position and a second position relative to the trigger. The lockout mechanism may further have a trigger stop connected to the handle, the trigger stop being movable between a first position and a second position relative to the handle. The release button may be pivotally movable relative to the trigger, or linearly movable in a direction lateral relative to the trigger. The release button may be biased to the first position by a release button biasing member. The trigger stop may be biased to the first position by a trigger stop biasing member. Movement of the trigger from the initial position toward the actuated position may engage the trigger with the trigger stop to automatically lock the trigger in the intermediate position. Movement of the release button from the first position to the second position when the trigger is in the intermediate position may permit disengagement of the trigger from the trigger stop.

According to some non-limiting examples, a ratcheting mechanism may be provided to engage the trigger when the trigger is moved from the intermediate position toward the actuated position to prevent movement of the trigger toward the initial position. The ratcheting mechanism may disengage from the trigger when the trigger is moved to the actuated position. The ratcheting mechanism may have a ratchet rod and a ratchet that is engaged with the ratchet rod when the trigger is moved from the intermediate position toward the actuated position. The ratcheting mechanism may be actuated when the trigger is moved from the intermediate position toward the actuated position by a predetermined distance.

According to some non-limiting examples, the surgical applicator may further have a jaw assembly selectively movable between an open position and a closed position via movement of the trigger from the initial position to the actuated position. The jaw assembly may have a pair of jaws movably attached to one another, with each jaw having a pair of lateral sides with a plurality of lateral slots extending through each lateral side. An outer surface of at least one of the lateral sides of each jaw may have a recess that receives a cover element for enclosing at least a portion of the plurality of lateral slots. The cover element may be adhesively secured in the recess. The jaws may be pivotally attached to one another by a pin. The surgical application may further include a dampening mechanism operatively arranged with the trigger to dampen variations in a compressive force applied on the trigger during movement between the initial position and the actuated position. The dampening mechanism may have a spring and a damper.

According to some non-limiting examples, a surgical applicator for a fastener may have a handle, a trigger movable relative to the handle between an initial position, an actuated position, and an intermediate position between the initial position and the actuated position, and a lockout mechanism. The lockout mechanism may include a release button connected to the trigger and a trigger stop connected to the handle. Movement of the trigger from the initial position toward the actuated position may engage the trigger stop with the trigger to lock the trigger in the intermediate position, and movement of the release button relative to the trigger when the trigger is in the intermediate position may disengage the trigger from the trigger stop to permit movement of the trigger from the intermediate position toward the initial position or the actuated position. The surgical applicator may further have a ratcheting mechanism that engages the trigger when the trigger is moved from the intermediate position toward the actuated position to prevent movement of the trigger toward the initial position. The ratcheting mechanism may disengage from the trigger when the trigger is moved to the actuated position.

According to some non-limiting examples, a surgical applicator for a fastener may have a handle, a trigger movable relative to the handle between an initial position, an actuated position, and an intermediate position between the initial position and the actuated position, and an elongate body extending distally from the handle. The elongate body may have a distal portion, a jaw assembly at the distal portion selectively movable between an open position, a closed position, and an intermediate position between the open position and the closed position via movement of the trigger. The surgical applicator may further have a lockout mechanism operatively arranged to lock the trigger and the jaw assembly in the intermediate position when the trigger is moved from the initial position toward the actuated position, and permit movement of the trigger from the intermediate position toward the initial position or the actuated position to move the jaw assembly from the intermediate position toward the open position or the closed position, respectively.

According to some non-limiting examples, a method of operating a fastener applicator may include moving a trigger of the fastener applicator from an initial position toward an actuated position by applying a compressive force on the trigger in a direction toward a handle of the fastener applicator, closing a jaw assembly of the fastener applicator from an open position toward a closed position via movement of the trigger, and locking the trigger and the jaw assembly in an intermediate position with a lockout mechanism. The method may further include moving the lockout mechanism from a locked position to an unlocked position, moving the trigger from the intermediate position toward the actuated position, and closing the jaw assembly from the intermediate position to the closed position via movement of the trigger. Closing the jaw assembly to the closed position may close a fastener from an unfixed position to a fixed position.

According to some non-limiting examples, the method may further include blocking the trigger via a ratcheting mechanism from movement toward the initial position after the trigger is moved from the intermediate position toward the actuated position. The jaw assembly may move from the closed position toward the open position when the trigger is moved to the actuated position, or after the trigger is moved to the actuated position. The method may further include unlocking the trigger when the trigger is moved to the actuated position.

Further examples of the present disclosure are set forth in the following numbered clauses.

Clause 1: A surgical applicator for a fastener, the surgical applicator comprising:

a handle;

a trigger movable relative to the handle between an initial position, an actuated position, and an intermediate position between the initial position and the actuated position; and

a lockout mechanism movable relative to the trigger between a locked position and an unlocked position, the lockout mechanism operatively arranged to:lock the trigger in the intermediate position when the trigger is moved from the initial position toward the actuated position; andpermit movement of the trigger from the intermediate position toward the initial position or the actuated position when the lockout mechanism is moved from the locked position to the unlocked position.

Clause 2: The surgical applicator of clause 1, wherein the lockout mechanism is further operatively arranged to permit movement of the trigger from the initial position to the actuated position when the lockout mechanism is moved from the locked position to the unlocked position prior to movement of the trigger from the initial position.

Clause 3: The surgical applicator of clause 1 or clause 2, wherein the trigger is movable relative to the handle from the initial position with application of a compressive force on the trigger in a direction toward the handle.

Clause 4: The surgical applicator of any of clauses 1-3, wherein the trigger has a distal side opposite a proximal side facing the handle, and wherein at least a portion of the lockout mechanism is positioned on the distal side of the trigger.

Clause 5: The surgical applicator of any of clauses 1-4, wherein the lockout mechanism comprises:

a release button connected to the trigger, the release button movable between a first position and a second position relative to the trigger, and

a trigger stop connected to the handle, the trigger stop movable between a first position and a second position relative to the handle.

Clause 6: The surgical applicator of clause 4, wherein the release button is pivotally movable relative to the trigger.

Clause 7: The surgical applicator of clause 4, wherein the release button is linearly movable in a direction lateral relative to the trigger.

Clause 8: The surgical applicator of clause 4, wherein the release button is biased to the first position by a release button biasing member.

Clause 9: The surgical applicator of clause 4, wherein the trigger stop is biased to the first position by a trigger stop biasing member.

Clause 10: The surgical applicator of clause 4, wherein movement of the trigger from the initial position toward the actuated position engages the trigger with the trigger stop to automatically lock the trigger in the intermediate position.

Clause 11: The surgical applicator of clause 4, wherein movement of the release button from the first position to the second position when the trigger is in the intermediate position permits disengagement of the trigger from the trigger stop.

Clause 12: The surgical applicator of any of clauses 1-11, further comprising a ratcheting mechanism that engages the trigger when the trigger is moved from the intermediate position toward the actuated position to prevent movement of the trigger toward the initial position.

Clause 13: The surgical applicator of clause 10, wherein the ratcheting mechanism disengages from the trigger when the trigger is moved to the actuated position.

Clause 14: The surgical applicator of clause 10, wherein the ratcheting mechanism comprises a ratchet rod and a ratchet that is engaged with the ratchet rod when the trigger is moved from the intermediate position toward the actuated position.

Clause 15: The surgical applicator of clause 10, wherein the ratcheting mechanism is actuated when the trigger is moved from the intermediate position toward the actuated position by a predetermined distance.

Clause 16: The surgical applicator of any of clauses 1-15, further comprising a jaw assembly selectively movable between an open position and a closed position via movement of the trigger from the initial position to the actuated position.

Clause 17: The surgical applicator of clause 16, wherein the jaw assembly comprises a pair of jaws movably attached to one another, each jaw having a pair of lateral sides with a plurality of lateral slots extending through each lateral side.

Clause 18: The surgical applicator of clause 17, wherein an outer surface of at least one of the lateral sides of each jaw has a recess.

Clause 19: The surgical applicator of clause 18, wherein the recess receives a cover element that encloses at least a portion of the plurality of lateral slots.

Clause 20: The surgical applicator of clause 17, wherein the cover element is adhesively secured in the recess.

Clause 21: The surgical applicator of clause 17, wherein the jaws are pivotally attached to one another by a pin.

Clause 22: The surgical applicator of any of clauses 1-21, further comprising a dampening mechanism operatively arranged with the trigger to dampen variations in a compressive force applied on the trigger during movement between the initial position and the actuated position.

Clause 23: The surgical applicator of clause 22, wherein the dampening mechanism comprises a spring and a damper.

Clause 24: A surgical applicator for a fastener, the surgical applicator comprising:

a handle;

a trigger movable relative to the handle between an initial position, an actuated position, and an intermediate position between the initial position and the actuated position; and

a lockout mechanism comprising a release button connected to the trigger and a trigger stop connected to the handle,

wherein movement of the trigger from the initial position toward the actuated position engages the trigger stop with the trigger to lock the trigger in the intermediate position, and

wherein movement of the release button relative to the trigger when the trigger is in the intermediate position disengages the trigger from the trigger stop to permit movement of the trigger from the intermediate position toward the initial position or the actuated position.

Clause 25: The surgical applicator of clause 24, further comprising a ratcheting mechanism that engages the trigger when the trigger is moved from the intermediate position toward the actuated position to prevent movement of the trigger toward the initial position.

Clause 26: The surgical applicator of clause 24 or clause 25, wherein the ratcheting mechanism disengages from the trigger when the trigger is moved to the actuated position.

Clause 27: A surgical applicator for a fastener, the surgical applicator comprising:

a handle;

a trigger movable relative to the handle between an initial position, an actuated position, and an intermediate position between the initial position and the actuated position;

an elongate body extending distally from the handle, the elongate body having a distal portion;

a jaw assembly at the distal portion of the elongate body, the jaw assembly selectively movable between an open position, a closed position, and an intermediate position between the open position and the closed position via movement of the trigger; and

a lockout mechanism operatively arranged to:lock the trigger and the jaw assembly in the intermediate position when the trigger is moved from the initial position toward the actuated position; andpermit movement of the trigger from the intermediate position toward the initial position or the actuated position to move the jaw assembly from the intermediate position toward the open position or the closed position, respectively.

Clause 28: A method of operating a fastener applicator, the method comprising:

moving a trigger of the fastener applicator from an initial position toward an actuated position by applying a compressive force on the trigger in a direction toward a handle of the fastener applicator;

closing a jaw assembly of the fastener applicator from an open position toward a closed position via movement of the trigger;

locking the trigger and the jaw assembly in an intermediate position with a lockout mechanism;

moving the lockout mechanism from a locked position to an unlocked position;

moving the trigger from the intermediate position toward the actuated position; and

closing the jaw assembly from the intermediate position to the closed position via movement of the trigger.

Clause 29: The method of clause 28, wherein closing the jaw assembly to the closed position closes a fastener from an unfixed position to a fixed position.

Clause 30: The method of clause 28 or clause 29, further comprising blocking the trigger via a ratcheting mechanism from movement toward the initial position after the trigger is moved from the intermediate position toward the actuated position.

Clause 31: The method of any of clauses 28-30, wherein the jaw assembly moves from the closed position toward the open position when the trigger is moved to the actuated position, or after the trigger is moved to the actuated position.

Clause 32: The method of any of clauses 28-31, further comprising unlocking the trigger when the trigger is moved to the actuated position.

InFIGS.1-13B, like characters refer to the same components and elements, unless otherwise stated.

DESCRIPTION OF THE PREFERRED EXAMPLES

Spatial or directional terms, such as “left”, “right”, “inner”, “outer”, “above”, “below”, and the like, are not to be considered as limiting as the invention can assume various alternative orientations. For purposes of the description hereinafter, the terms “end,” “upper,” “lower,” “right,” “left,” “vertical,” “horizontal,” “top,” “bottom,” “lateral,” “longitudinal,” and derivatives thereof shall relate to the invention as it is oriented in the drawing figures.

As used in the specification and the claims, the singular form of “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.

All numbers used in the specification and claims are to be understood as being modified in all instances by the term “about”. By “about” is meant a range of plus or minus ten percent of the stated value.

Unless otherwise indicated, all ranges or ratios disclosed herein are to be understood to encompass any and all subranges or subratios subsumed therein. For example, a stated range or ratio of “1 to 10” should be considered to include any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges or subratios beginning with a minimum value of 1 or more and ending with a maximum value of 10 or less, such as but not limited to, 1 to 6.1, 3.5 to 7.8, and 5.5 to 10.

The terms “first”, “second”, and the like are not intended to refer to any particular order or chronology, but instead refer to different conditions, properties, or elements.

By “at least” is meant “greater than or equal to”. By “not greater than” is meant “less than or equal to”.

The term “includes” is synonymous with “comprises”.

The terms “proximal” or “proximally”, when used in reference to any portion of the fastener applicator, refer to a portion of the fastener applicator closest to a body of a user handling the fastener applicator during use of the fastener applicator. Conversely, the terms “distal” or “distally”, when used in reference to any portion of the fastener applicator, refer to a portion of the fastener applicator furthest away from a body of a user handling the fastener applicator during use of the fastener applicator.

It is to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary examples or aspects of the invention. Hence, specific dimensions and other physical characteristics related to the examples or aspects disclosed herein are not to be considered as limiting.

Various examples of the present disclosure provide alternative and improved devices, systems, and methods for deploying one or more closure devices or fasteners to tissue. An exemplary tissue structure of a patient at risk of stroke or other adverse events resulting from emboli released into circulation from the LAA, may include the LAA.

Referring now toFIG.1, a fastener applicator10(also referred to herein as “surgical applicator” or “applicator”) constructed in accordance with various examples of the present disclosure has a shaft12having a handle assembly17at its proximal end13, and a jaw assembly16at a distal end15, where individual jaws18,20are adapted to carry a fastener22(shown inFIG.2). The handle assembly17has a trigger32movable relative to a handle34between an initial position, an actuated position, and an intermediate position between the initial position and the actuated position. The trigger32is movable relative to the handle34from the initial position with application of a compressive force on the trigger32in a direction toward the handle34(arrow A inFIG.1). In various examples of the present disclosure, the fastener applicator10is configured for introducing the fastener22over the tissue structure.

With reference toFIG.2, the fastener22is shown in accordance with one non-limiting example of the present disclosure. The fastener22has a substantially U-shaped configuration for receiving the tissue structure, such as the LAA or other tissue structure, when the jaws18,20of the fastener applicator10are open. The fastener22has a compressible body24and a pair of parallel legs26having two opposed compliant tissue-engaging surfaces28. The legs26are movable between an open or unfixed position and a closed or fixed position. In some examples, the legs26are each comprised of a soft biologically compatible material. The fastener22further has a plurality of tissue-penetrating fasteners30spaced-apart along the legs26and disposed to extend from a first one of the tissue-engaging surfaces28, through tissue at a puncture site, to a second one of the tissue-engaging surfaces28to close the tissue structure therebetween. The plurality of tissue-penetrating fasteners30apply a desired level of compression force, which is determined by both the softness of the compressible body24and the distance between the tissue-engaging surfaces28when they are fully connected to the tissue structure. When connected to the tissue structure, the fastener22is left in place in order to close and/or seal the tissue structure. A portion of the tissue structure extending beyond the fastener22may then be cut, excised, or otherwise removed, although this may be left to the physician's preference. More detailed description of various fasteners suitable for use with the fastener applicator10of the present disclosure are described in U.S. Pat. No. 7,992,757, the full disclosure of which is incorporated herein by reference.

Referring now toFIG.3, an exploded view of the fastener applicator10ofFIG.1is shown. The handle assembly17has a housing36comprising a first housing portion36aand a second housing portion36bcoupled to one another and defining an interior space for receiving the working components of the handle assembly17. The first housing portion36aand the second housing portion36b, when assembled together, define the handle34that is grasped by the user when handling the fastener applicator10. In some examples, the first and second portions36a,36bof the housing36are coupled using one or more handle fasteners38. In other examples, the first and second portions36a,36bof the housing36may be coupled using clips, grooves, adhesive, welding, or any other mechanical fastening arrangement. In various examples, the first and second portions36a,36bof the housing36may be removably or non-removably coupled to one another.

With continued reference toFIG.3, the interior space of the housing36receives various components for actuating the surgical applicator10between an initial position, an actuated position, and an intermediate position between the initial position and the actuated position. For example, the housing36may receive various gears, linkages, springs, or the like to effect movement or actuation of the trigger32between the initial position, the actuated position, and the intermediate position between the initial position and the actuated position. As discussed herein, the housing36receives at least a portion of the trigger32that is movable relative to the housing36in a pivoting motion about a trigger pivot pin44. The trigger32may be biased to the initial position by a trigger biasing member, such as a trigger spring38. The trigger spring38is compressible with movement of the trigger32from the initial position such that a restoring force is generated in the trigger spring38that restores the trigger32to the initial position when an urging force on the trigger32is removed or reduced to a magnitude that is lower than the restoring force of the trigger spring38. In some examples, the trigger32has a trigger stop40pivotally connected to at least a portion of the housing36. The trigger stop40may be movable between a first position and a second position relative to the handle34. The trigger stop40is biased to the first position by a trigger stop biasing member, such as a dampening spring50.

With continued reference toFIG.3, the housing36receives a ratcheting mechanism46having a ratchet rod120and a ratchet128, as discussed herein. The ratcheting mechanism46engages when the trigger32is moved from the intermediate position toward the actuated position to prevent movement of the trigger32toward the initial position. In some examples, the ratcheting mechanism46disengages when the trigger32reaches the actuated position such that the trigger32automatically moves toward the initial position when the ratcheting mechanism46is disengaged, or when the force applied to the trigger is relieved. A dampening mechanism48is received within the housing36and operatively arranged with the trigger32to dampen variations in a compressive force applied on the trigger32during movement between the initial position and the actuated position. In some examples, the dampening mechanism48has a dampening spring50received within a damper plunger52and a damper54. In various examples, the damper54may be a friction damper, an elastomeric damper, a magnetic damper, a viscous damper, or any combination thereof.

With reference toFIG.4A, the jaw assembly16is illustrated separate from the remaining components of the fastener applicator10.FIG.4Bis an exploded view of the jaw assembly16ofFIG.4A. As described herein, the jaw assembly16is movable between an open position (shown inFIGS.4A-4B) and a closed position (shown inFIGS.8B-8C) via movement of the trigger32from the initial position to the actuated position. The jaw assembly16comprises a pair of jaws18,20movably attached to one another. In some examples, the jaws18,20are pivotally attached to one another with a hinge pin56and a washer58. In some examples, the hinge pin56and the washer58may be welded together, such as using laser welding, ultrasonic welding, or other type of welding. In other examples, the hinge pin56and the washer58are adhesively connected with each other, threadably connected with each other, or connected by way of any other removable or non-removable mechanical connection.

With continued reference toFIGS.4A-4B, each jaw18,20has a pair of lateral sides60, with each lateral side60having a plurality of lateral slots62extending therethrough. The lateral slots62define a channel for guiding the movement of jaw cam pins64. A single jaw cam pin64is received within each lateral slot62and is movable within the lateral slot62between a first position and a second position. In the first position, the jaw cam pins64in each jaw18,20are positioned relative to a stud comb66such that the comb66is in an extended or exposed position within the jaws18,20. In the second position, the jaw cam pins64in each jaw18,20are positioned such that the jaw cam pins64urge the stud comb66in each jaw18,20to a retracted or concealed position, wherein the comb66acts on the tissue penetrating fasteners30of the fastener22.

With continued reference toFIGS.4A-4B, the jaws18,20are received within a clamp box68. In some examples, the clamp box68has a pair of sides68a,68bdefining a central opening70therebetween for receiving the jaws18,20. The sides68a,68bof the clamp box68may be removably or non-removably connected to one another, such as by one or more rivets72. The movement of the jaws18,20between the open and closed positions is guided by the interaction between the guide slots63on each of the jaws18,20and a corresponding guide pin65(shown inFIG.4B) on the clamp box68.

The clamp box68receives a distal end74of at least a portion of the shaft14, such as the distal end of the clamp tube76. With reference toFIGS.4C-4E, the shaft14comprises the clamp tube76slidably received within an ejection tube77and an inner pull rod78slidably received within the clamp tube76such that the clamp tube, ejection tube77, and the inner pull rod78are coaxially disposed relative to one another. The clamp tube76may be rotatable about its longitudinal axis to rotate the clamp box68and the jaws18,20, thereby facilitating the orientation of the jaws18,20relative to the handle assembly17during use of the fastener applicator10. In some examples, the shaft14is rotatable about its longitudinal axis with rotation of the positioning knob88(shown inFIG.5).

The pull rod78is axially movable relative to the clamp tube76with movement of the trigger32. For example, the pull rod78may be movable in a direction extending between the proximal and distal ends of the shaft14and along a longitudinal axis thereof. Movement or closure of the trigger32from the initial position toward the actuated position draws the pull rod78proximally toward a proximal end80of the shaft14relative to the clamp tube76and the ejection tube77, which in turn closes the jaws18,20. The ejection tube77has at least one tendon82connected at its distal end. The at least one tendon82is operatively connected with the comb stud66such that movement of the trigger32to the activated position also pulls the at least one tendon82to cause the retraction of the comb stud66.

With reference toFIGS.4A-4B, an outer surface of at least one of the lateral sides60of each jaw18,20has a recess84. The recess84may be formed as a channel that extends into the body of each jaw18,20from the lateral sides60in a region surrounding the lateral slots62. In some examples, the recess84receives a cover element86(also shown inFIG.3) that encloses at least a portion of the plurality of lateral slots62. A thickness of the cover element86may be chosen such that an outer surface of the cover element86may be flush with the surface of the lateral side60. In other examples, the thickness of the cover element86may be chosen such that its outer surface is recessed relative to the surface of the lateral side60, or such that the outer surface of the cover element86protrudes laterally from the surface of the lateral side60. In some examples, the cover element86may be adhesively secured in the recess84. In further examples, the cover element86may be transparent such that the lateral slots62and the jaw cam pins64can be seen through the cover element86. When positioned in the recess84, the cover element86prevents contamination of the lateral slots62and the jaw cam pins64during use of the fastener applicator10which may cause the blockage of one or more lateral slots62and/or impede the movement of one or more jaw cam pins64through the lateral slots62.

With reference toFIG.5, the trigger32comprises a first trigger portion32aand a second trigger portion32bcoupled to one another. The first trigger portion32aand the second trigger portion32b, when assembled together, define the trigger32that is grasped by the user when handling the fastener applicator10. In some examples, the first and second trigger portions32a,32bare coupled using one or more trigger fasteners90. In other examples, the first and second trigger portions32a,32bmay be coupled using clips, grooves, adhesive, welding, press fit, or any other mechanical fastening arrangement. In various examples, the first and second trigger portions32a,32bmay be removably or non-removably coupled to one another.

With continued reference toFIG.5, each trigger portion32a,32bhas a first end92that is received within the housing36(shown inFIG.3) and pivotally movable relative to the housing36. A second free end94extends opposite the first end92and protrudes outside the housing36. The second free end94of the trigger32is configured for being grasped by the user during movement of the trigger32between the initial position and the activated position. The trigger32further has a distal side110opposite a proximal side108facing the handle. As described herein, at least a portion of a lockout mechanism is positioned on the distal side110of the trigger32.

With continued reference toFIG.5, the trigger32has a pivot pin opening112configured for receiving the trigger pivot pin44(shown inFIG.3). The trigger32is pivotally movable about a longitudinal axis of the trigger pivot pin44which has its terminal ends secured to the housing36. A trigger slot114extends through the body at the first end92of the trigger32. The trigger slot114is configured to receive a closing trunnion116connected to the distal end of the pull rod78. The trigger slot114acts as a camming mechanism for controlling the movement of the pull rod78due to the movement of the closing trunnion116within the trigger slot114. In some examples, the shape of the trigger slot114is configured to result in a linear movement of the pull rod78in a direction of a longitudinal axis118of the shaft14as a result of a pivoting movement of the trigger about the trigger pivot pin44. The closing trunnion116may contact or be positioned in near contact with a first end of the trigger slot114when the trigger32is in the initial position (FIG.7A). Similarly, the closing trunnion116may contact or be positioned in near contact with a second end (opposite the first end) of the trigger slot114when the trigger32is in the actuated position (FIG.7E). The closing trunnion116may be positioned between the first end and the second end of the trigger slot114when the trigger32is in the intermediate position between the initial position and the actuated position. Lateral pins of an ejection trunnion164are received within an opening123extending through a first end of a trigger sub lever122(see, also,FIGS.10A-10C) such that movement of the trigger32also causes a corresponding movement of the trigger sub lever122due to movement of the ejection trunnion164within the trigger slot114(seeFIGS.10A-10C).

With continued reference toFIG.5, a second end of the trigger sub lever122has a pin125that is pivotally connected to the trigger32. In this manner, the first end of the trigger sub lever122is slidably movable relative to the trigger slot166and the ejection trunnion164, while the second end of the trigger sub lever122is pivotally movable relative to the trigger sub stop feature172on the handle34(seeFIGS.10A-10C). When the second end of trigger sub lever122strikes the trigger sub stop feature172on the handle34, and the trigger32continues moving proximally toward an actuated position, relative motion of the first end of the trigger sub lever122is amplified by pivoting about a pin125. Amplification is determined by the ratio of the two distances L1and L2inFIG.10B. L1is the distance between the trigger sub stop feature172and the trigger sub lever pin125while L2is the distance between the trigger sub lever pin125and the ejection trunnion164. The trigger sub lever122effects the ejection trunnion164via the trigger sub lever slot170. In this manner, a first (small) movement of the trigger32can have a second (greater) movement on the ejection trunnion164due to the ejection trunnion164being linked to the ejection tube77. In this manner, the combs66can be retracted via the tendons82to release the fastener22(shown inFIG.2).

With reference toFIG.6A, the fastener applicator10has a lockout mechanism140amovable relative to the trigger32between a locked position and an unlocked position. The lockout mechanism140ainFIG.6Ais shown in accordance with one example of the present disclosure. The lockout mechanism140ais operatively arranged to lock the trigger32in the intermediate position (FIG.7B) when the trigger32is moved from the initial position toward the actuated position. The lockout mechanism140ais further operatively arranged to permit movement of the trigger32from the intermediate position toward the initial position or the actuated position when the lockout mechanism is moved from the locked position to the unlocked position (FIG.7C). The lockout mechanism140ais further operatively arranged to lock the trigger32in the initial position when a trigger release button96is moved from the first position to the second position prior to movement of the trigger32from the initial position.

With continued reference toFIG.6A, the lockout mechanism140acomprises the trigger release button96, the trigger stop40, and the ratcheting mechanism46. As described herein, movement of the trigger32from the initial position toward the actuated position engages the trigger32with the trigger stop40and moves the trigger stop40to automatically lock the trigger32in the intermediate position. To release the trigger32from the intermediate position, movement of the trigger release button96from the first position to the second position about the trigger release button pivot pin100when the trigger32is in the intermediate position permits disengagement of the trigger stop40from the trigger32. In this manner, the trigger32can be retracted to the initial position due to a restoring force of the trigger spring38or moved to the actuated position to close the fastener22(shown inFIG.2).

The trigger release button96extends through an opening98on the trigger32between the first end92and the second free end94(FIG.5). In various examples, the trigger release button96is positioned relative to the first and second ends92,94of the trigger32such that the trigger release button96may be operated using the user's index finger that contacts a pressing surface97of the trigger release button96. The trigger release button96is movable between a first position, wherein the trigger release button96protrudes from the opening98, and a second position, wherein at least a portion of the trigger release button96is moved into the opening98on the trigger. In some examples, the trigger release button96may protrude from the opening98in the first position and the second position.

The trigger release button96is pivotally movable relative to the trigger32between the first position and the second position about the first trigger release button pivot pin100. In other examples, the trigger release button96may be linearly movable relative to the trigger32, such as by movement in a proximal/distal direction of the fastener applicator10, or in a lateral direction relative to the trigger32. A trigger release button slot104in the trigger release button96receives a second trigger release button pin106and may delimit a range of movement of the trigger release button96. The second trigger release button pin106may contact or be positioned in near contact with a first end of the trigger release button slot104when the trigger release button96is in the first position. Similarly, the second trigger release button pin106may contact or be positioned in near contact with a second end (opposite the first end) of the trigger release button slot104when the trigger release button96is in the second position.

The trigger release button96is biased to the first position by a release button biasing member, such as a trigger release button spring102. The trigger release button spring102is compressible with movement of the trigger release button96from the first position toward the second position such that a restoring force is generated in the trigger release button spring102that restores the trigger release button96to the first position when an urging force on the trigger release button96is removed and the trigger release button96is disconnected from the trigger stop40.

With continued reference toFIG.6A, the trigger release button96has a stop member150positioned at a second free end95of the trigger release button96and configured for engaging at least a portion of the trigger stop40to prevent movement of the trigger32from the initial position if the trigger release button96is pressed before the trigger32is moved to the intermediate position. In this manner, the trigger32can be moved from the initial position only if the trigger release button96is not pressed. In some examples, the stop member150may be configured as a rounded tip at the second end of the trigger release button96.

With continued reference toFIG.6A, the trigger release button96has a trigger stop release member152positioned between the first trigger release button pivot pin100and the stop member150. The trigger stop release member152is configured for engaging at least a portion of the trigger stop40when the trigger32is positioned in the intermediate position between the initial position and the actuated position. Pressing the trigger release button96when the trigger32is in the intermediate position engages the trigger stop release member152with the trigger stop40to unlock the trigger stop40and permit movement of the trigger32from the intermediate position toward the actuated position or the initial position. In some examples, the trigger stop release member152may be shaped as a rounded protrusion at a proximal portion of the trigger release button96between the first trigger release button pivot pin100and the stop member150.

A non-limiting example embodiment of a trigger release button96ais shown inFIG.11. The embodiment of the trigger release button96aincludes a pressing surface97a, a trigger release button slot104a, and a stop member150a. In the embodiment of the trigger release button96ashown inFIG.11, the pressing surface97aincludes a raised cross pattern197, which provides a distinct surface for the user to locate the trigger release button and an increased grip to the user, thereby making the fastener applicator easier to use. This non-limiting example embodiment of trigger release button96acan be used in the embodiments of the fastener applicator of the present disclosure, including the embodiments of the fastener applicator shown inFIGS.6A,6B and7A-7E.

With continued reference toFIG.6A, the trigger stop40is connected to the handle34and is movable relative to the handle34between a first position (FIG.7A) and a second position (FIG.7E). The trigger stop40is biased to the first position by a trigger stop biasing member, such as the dampening spring50(FIG.3). In some examples, the trigger stop40is pivotally movable relative to the handle34between the first position and the second position about a trigger stop pin142. The trigger stop40has a first end144that is pivotable about the trigger stop pin142and a second free end146opposite the first end144.

At least a portion of the trigger stop40may be recessed within the housing36of the handle34when the trigger stop40is in the first position. For example, the first end144and the second end146of the trigger stop40may be recessed within the housing36of the handle34when the trigger stop40is in the first position. In some examples, at least a portion of the trigger stop40may extend from the housing36of the handle34when the trigger stop40is pivoted from the first position toward the second position. For example, the first end144of the trigger stop40may be recessed within the interior of the housing36of the handle34while at least a portion of the second end146of the trigger stop40protrudes from the interior of the housing36when the trigger stop40is pivoted from the first position toward the second position.

With continued reference toFIG.6A, the trigger stop40has a dampening cam148configured for interacting with the dampening mechanism48when the trigger32is moved from the intermediate position toward the actuated position. The dampening cam148is positioned at the first end144of the trigger stop40and is shaped to vary the displacement of the dampening spring50(shown inFIG.3) and the dampening plunger52during the stroke of the trigger32between the intermediate position toward the actuated position. As the dampening plunger52is compressed against the restoring force of the dampening spring50, the dampening plunger52engages the damper54(shown inFIG.7E). In some examples, the dampening cam148on the trigger stop40and the dampening mechanism48may be configured to require a persistent resistive force on the trigger32during movement of the trigger32from the intermediate position toward the final position regardless of the position of the trigger32during its stroke between the intermediate position and the final position. In this manner, the user does not need to vary the force input on the trigger32during activation of the fastener applicator10which may inadvertently change the position of the jaw assembly16(shown inFIG.1) relative to the tissue structure.

With continued reference toFIG.6A, the second end146of the trigger stop40has a first stop member engagement surface154configured for engaging the stop member150of the trigger release button96if the trigger release button96is pressed while the trigger32is positioned in the initial position. Contact between the first stop member engagement surface154of the trigger stop40and the stop member150of the trigger release button96prevents movement of the trigger32from the initial position toward the actuated position if the trigger release button96is pressed before the trigger32is moved to the intermediate position. In this manner, the trigger32is locked in the initial position until the trigger release button96is released, thereby disengaging the first stop member engagement surface154of the trigger stop40from the stop member150of the trigger release button96. In some examples, the first stop member engagement surface154of the trigger stop40may be configured as a recess at a terminal portion of the second end146of the trigger stop40.

Movement of the trigger32to the intermediate position locks the trigger32relative to the handle34due to engagement of a trigger latch156on the trigger stop40with a trigger catch158on the trigger32. In some examples, the trigger latch156on the trigger stop40is configured as at least one protrusion that extends laterally away from at least one lateral side of the trigger stop40. In some examples, the trigger latch156is a pair of protrusions that extend laterally away from opposing lateral sides of the trigger stop40. The trigger catch158on the trigger32may be configured as a recess on a proximal side108of the trigger32that is shaped to receive at least a portion of the trigger latch156.

The trigger latch156and the trigger catch158engage when the trigger32is moved to the intermediate position and prevent movement of the trigger32toward the initial position or the actuated position. The trigger latch156and the trigger catch158are disengaged by pressing the trigger release button96, whereby at least a portion of the trigger release button96contacts at least a portion of the trigger stop40to move the trigger stop40and displace the trigger latch156from contact with the trigger catch158on the trigger32. In some examples, the stop member150of the trigger release button96engages a release surface160on the trigger stop40to move the trigger stop40and displace the trigger latch156from contact with the trigger catch158on the trigger32. The release surface160may be positioned at the second end146of the trigger stop40and proximally of the stop member150.

With continued reference toFIG.6A, the trigger stop40has a trigger actuation surface162positioned proximally of a second stop member engagement surface155and the release surface160. The trigger actuation surface162of the trigger stop40is configured for engaging the trigger stop release member152of the trigger release button96when the trigger32is moved from the intermediate position toward the actuated position while the trigger release button96is pressed. Pressing the trigger release button96when the trigger32is moved from the intermediate position toward the actuated position engages the trigger stop release member152with the trigger actuation surface162of the trigger stop40to unlock the trigger stop40and permit movement of the trigger32toward the actuated position. In some examples, the trigger actuation surface162may be shaped as a ramp that engages the trigger stop release member152of the trigger release button96. In examples where the trigger actuation surface162is shaped as a slot, the trigger actuation surface162provides clearance for movement of the trigger stop release member152along the trigger actuation surface162.

A non-limiting example embodiment of a trigger stop40ais shown inFIGS.12A and12B. The embodiment of the trigger stop40aincludes a first end144a, a second end146a, a dampening cam148a, a first stop member engagement surface154a, a trigger latch156a, a release surface160a, and a trigger actuation surface162a. This non-limiting example embodiment of trigger stop40acan be used in the embodiments of the fastener applicator of the present disclosure, including the embodiments of the fastener applicator shown inFIGS.6A,6B and7A-7E.

With continued reference toFIG.6A, the lockout mechanism140afurther comprises the ratcheting mechanism46that engages when the trigger32is moved from the intermediate position toward the actuated position. The ratcheting mechanism46is configured to prevent movement of the trigger32toward the initial position after the trigger32has been moved from the intermediate position toward the actuated position. In some examples, the ratcheting mechanism46is actuated when the trigger32is moved from the intermediate position toward the actuated position by a predetermined distance. In further examples, the ratcheting mechanism46is actuated when the trigger actuation surface162of the trigger stop40engages the trigger stop release member152of the trigger release button96as the trigger32is moved from the intermediate position toward the actuated position while the trigger release button96is pressed. In further examples, the ratcheting mechanism46is configured to automatically disengage when the trigger32reaches the actuated position to permit movement of the trigger32back toward to the initial position.

The ratcheting mechanism46comprises a ratchet rod120that is selectively engagable with a ratchet lever128when the trigger32is moved from the intermediate position toward the actuated position. The ratchet rod120is movable axially in a distal-to-proximal direction as the trigger32is pivoted from the intermediate position (FIG.7A) toward the actuated position (FIG.7E). The ratchet rod120is linked to the trigger32via a coupler131(shown inFIG.5). The ratchet rod120can pivot relative to the trigger32about the pins168(shown inFIG.5). The ratchet lever128is movable between an initial position (FIG.7A) and an engaged position (FIGS.7D-7E). In some examples, the ratchet lever128is pivotable about a ratchet pivot pin132. The ratchet lever128may be biased in a direction toward the initial position by a ratchet lever biasing mechanism, such as a ratchet lever spring134. Moving the trigger32from the initial position (FIG.7A) toward the actuated position (FIG.7E) results in an axial movement of the pull rod78in a proximal direction of the longitudinal axis118of the shaft14and an axial movement of the ratchet rod120in the proximal direction.

With continued reference toFIG.6A, the proximal end of the ratchet rod120has one or more teeth130that interact with a ratchet lever128. Movement of the ratchet rod120in the proximal direction due to movement of the trigger32from the intermediate position toward the actuated position engages the proximal end of the ratchet rod120with the ratchet lever128. The initial contact between the proximal end of the ratchet rod120with the ratchet lever128displaces the ratchet lever128from the disengaged position toward the engaged position by pivoting the ratchet lever128against the ratchet lever spring134.

The one or more teeth130of the ratchet rod120engage a locking tip136of the ratchet lever128when the trigger32is moved from the intermediate position toward the actuated position to prevent movement of the trigger32from the intermediate position toward the initial position. The ratchet rod120can include any number of teeth such that the trigger32can be progressively closed (i.e., brought into approximation of the handle32) by more fully driving the ratchet rod120under the ratchet lever128in the direction of closure for the trigger32(e.g., from the configuration ofFIG.7Ato the configuration ofFIG.7E).

In some examples, the ratchet lever128may engage the ratchet rod120prior to the trigger32reaching the actuated position to prevent reverse movement of the trigger from the actuated position toward the initial position. For example, the proximal end of the ratchet rod120can contact a ratchet lever engagement surface138at a proximal end of the ratchet lever128. The ratchet lever engagement surface138may be angled such that proximal movement of the ratchet rod120pivots the ratchet lever128. In some examples, the ratchet lever128can be locked due to engagement of one or more locking tabs139on the ratchet lever128with at least a portion of the housing36. In some examples, the one or more locking tabs139may be laterally deflectable between a first position, wherein the ratchet lever128can freely pivot about the ratchet pivot pin132, and a second position, wherein the ratchet lever128is locked relative to the housing36. The one or more locking tabs139may strike the housing36, thus causing a loud click to audibly alert the user that the trigger32has reached the actuated position and that jaws18,20have been closed. This audible confirmation indicates to the user that the fastener22has been closed and that the trigger32can be released. Once the one or more locking tabs139of the ratchet lever128engage the housing36, the ratchet lever128is locked in a disengaged state relative to the ratchet rod120.

A non-limiting example embodiment of a ratchet lever128ais shown inFIGS.13A and13B, and ratchet lever128aincludes a locking tip136aand two locking tabs139a. This non-limiting example embodiment of ratchet lever128acan be used in the embodiments of the fastener applicator of the present disclosure, including the embodiments of the fastener applicator shown inFIGS.6A,6B and7A-7E.

With reference toFIG.6B, the fastener applicator10is shown with a lockout mechanism140bin accordance with another example of the present disclosure. The components of the lockout mechanism140bshown inFIG.6Bare substantially similar to the components of the lockout mechanism140adescribed herein with reference toFIG.6A. As the previous discussion regarding the lockout mechanism140agenerally shown inFIG.6Ais applicable to the lockout mechanism140bshown inFIG.6B, only the relative differences between the two lockout mechanisms are discussed hereinafter.

With continued reference toFIG.6B, the trigger release button96has a stop member150positioned at a second free end95of the trigger release button96and configured for engaging at least a portion of the trigger stop40only when the trigger32is moved to the intermediate position. Unlike the trigger release button96and the trigger stop40shown inFIG.6A, the trigger release button96and the trigger stop40ofFIG.6Bare configured to allow movement of the trigger32from the initial position even if the trigger release button96is pressed before the trigger32is moved from the initial position. In other words, if the trigger release button96is pressed and held, the trigger32can pass through the intermediate position without stopping and ultimately to the actuated position.

With continued reference toFIG.6B, the trigger stop release member152of the trigger release button96is configured for engaging at least a portion of the trigger stop40when the trigger32is positioned in the intermediate position between the initial position and the actuated position. Pressing the trigger release button96when the trigger32is in the intermediate position engages the trigger stop release member152with the trigger stop40to unlock the trigger stop40and permit movement of the trigger32from the intermediate position toward the actuated position. In some examples, pressing the trigger release button96when the trigger32is in the initial position engages the trigger stop release member152with the trigger stop40to unlock the trigger stop40and permit movement of the trigger32from the initial position toward the actuated position, thereby bypassing the locking of the trigger32in the intermediate position.

With continued reference toFIG.6B, the first stop member engagement surface154of the trigger stop40is configured as a substantially planar portion at a terminal portion of the second end146of the trigger stop40. Similarly, the second stop member engagement surface155may be substantially planar, as opposed to the recessed configuration shown inFIG.6A. Pressing the trigger release button96prior to moving the trigger32from the intermediate position toward the actuated position engages the trigger stop release member152with the second stop member engagement surface155and the trigger actuation surface162of the trigger stop40to unlock the trigger stop40and permit movement of the trigger32toward the actuated position.

Having described the structure of the fastener applicator10, a method of using the fastener applicator10to close the fastener22over the tissue structure will now be described with reference toFIGS.7A-8D and10A-10C. With initial reference toFIG.7A, the fastener applicator10is shown in an initial or as-delivered configuration, wherein the trigger32is positioned in the initial position and the jaws18,20(shown inFIG.8A) are in an open configuration to receive the fastener22therebetween. After the fastener22is advanced over the tissue structure, such as the LAA, the jaws18,20are closed by manually moving the trigger32toward the handle34in the direction of arrow A inFIG.7B. The trigger32can be moved toward the handle34from the initial position (FIG.7A) by directing a proximally-directed force in the direction of arrow A on a distal side110of the trigger32.

Closing the trigger32with respect to the handle34, that is, pivoting about the trigger pivot pin44from the initial position of the trigger32(shown inFIG.10AorFIG.7A), draws the pull rod78proximally toward a proximal end of the shaft14relative to the clamp tube76, which in turn closes the jaws18,20(FIG.8B). The trigger32can be moved in a proximal direction to close the jaws18,20or distally to open the jaws18,20during positioning of the fastener22relative to the tissue structure provided that the trigger32is not advanced past the intermediate position. This allows the user to carefully position the fastener22relative to the tissue structure without closing the fastener22.

With reference toFIG.7B, the trigger32is shown in the intermediate position, wherein the trigger32is temporarily locked relative to the handle34due to engagement of a trigger latch156on the trigger stop40with a trigger catch158on the trigger32. When the trigger32is moved to the intermediate position and locked therein, further movement of the trigger32toward the initial position or the actuated position is prevented without further user input via the trigger release button96. With the trigger32locked in the intermediate position, the jaws18,20are closed in a “preview” position, wherein the legs26of the fastener22are brought toward one another to capture the tissue structure therebetween without engaging the tissue penetrating fasteners30(FIG.8A). This allows the user to preview the positioning of the fastener22relative to the tissue structure without closing the fastener22.

If repositioning of the fastener22relative to the tissue structure is necessary, the trigger32can be unlocked by pressing the trigger release button96to disengage the trigger latch156from the trigger catch158(FIG.7C). By pressing the trigger release button96, at least a portion of the trigger release button96, such as the stop member150of the trigger release button96, contacts at least a portion of the trigger stop40, such as the release surface160on the trigger stop40, to move the trigger stop40and displace the trigger latch156from contact with the trigger catch158on the trigger32. The trigger32can then be moved distally relative to the handle34due to a restoring force of the trigger spring42(shown inFIG.3). Movement of the trigger32toward the initial position and away from the handle34opens the jaws18,20to allow repositioning of the fastener22.

Referring now toFIG.7D, if the fastener applicator10is oriented such that the fastener22is arranged at a desired position relative to the tissue structure, the trigger32is unlocked from the intermediate position by pressing the trigger release button96to disengage the trigger latch156from the trigger catch158. The trigger32can then be advanced proximally toward the handle34by moving the trigger32in the direction of arrow A. Closing the trigger32with respect to the handle34moves the trigger stop40from a first position (FIG.7C) to a second position (FIG.7E) relative to the handle34to allow further proximal movement of the trigger32toward the actuated position.

Closing the trigger32with respect to the handle34also proximally retracts the ratchet rod120which is linked to the trigger32. With reference toFIG.10C, with the trigger32positioned in the actuated position, the trunnion116moves to a proximal end of the trigger slot114such that a center of the trunnion116, and therefore the opening123, is spaced apart proximally from a center of the trigger pivot pin44by a second predetermined distance X2that is larger than the first predetermined distance X1shown inFIG.10A. The trigger sub lever122is oriented such that its terminal end contacts the ratchet rod120and advances the ratchet rod120in a proximal direction. Proximal movement of the ratchet rod120due to movement of the trigger32past the intermediate position engages the teeth130of the ratchet rod120with the locking tip136of the locking lever128, thereby activating the ratcheting mechanism46. Once the ratcheting mechanism46is engaged, retraction of the trigger32in a direction toward the initial position (FIG.7A) is prevented. In this manner, the user is committed to closing the fastener22on the tissue structure by fully engaging the trigger32toward the actuated position.

Closure of the trigger32from the intermediate position toward the actuated position further draws the pull rod78proximally toward a proximal end of the shaft14relative to the clamp tube76. The ejection tube77pulls at least one tendon82to retract the comb studs66. When the jaws18,20are closed, the stud combs66engage the tissue penetrating fasteners30so that they engage and lock with each other, thus closing the two legs26of the fastener22, as shown inFIG.8C.

As the trigger32is advanced from the intermediate position toward the actuated position, the trigger stop40is deflected by the trigger32from the first position (FIG.7A) toward the second position (FIG.7E). As the trigger stop40moves from the first position to the second position, the dampening cam148of the trigger stop40contacts the damper plunger52of the dampening mechanism48, thereby compressing the dampening spring50(shown inFIG.3). As the dampening plunger52is compressed against the restoring force of the dampening spring50, the dampening plunger52engages the damper54(shown inFIG.7E), which provides resistance to the compressive force directed to the trigger32in the direction of arrow A. As described herein, the dampening cam148on the trigger stop40and the dampening mechanism48are configured such that the user feels a substantially constant reactive force from the trigger32during movement of the trigger32from the intermediate position toward the final position regardless of the position of the trigger32during its stroke between the intermediate position and the actuated position. For example, the user may perceive a substantially constant reactive force from the trigger32while moving the trigger32toward the handle34in the direction of arrow A, thereby requiring a substantially constant compressive force on the trigger32during movement of the trigger32from the intermediate position toward the actuated position.

Referring now toFIG.7E, the trigger32is moved to the actuated position to release the trigger32from the ratcheting mechanism46and allow retraction of the trigger32toward the initial position. As described herein, the proximal end of the ratchet rod120contacts a ratchet lever disengagement surface138at a proximal end of the ratchet lever128, which lifts the ratchet lever128from the ratchet rod120and prevents reengagement with the ratchet rod120due to interaction of the one or more locking tabs139on the ratchet lever128with at least a portion of the housing36. The jaws18,20may be opened by releasing manual compression on the trigger32, thereby allowing the trigger spring38and the main spring42, which was compressed during closure of the trigger32to push the ratchet rod120distally forward, opening the jaws18,20and leaving the fastener22in place (FIG.8D).

Referring now toFIG.9, one specific example of use is illustrated. In this example, the fastener applicator10is used to deliver a fastener22over the base of a left atrial appendage LAA in an open chest, beating heart procedure. The sternum S is opened, spreading the ribs R to provide a working space over the heart H. After opening the pericardial sack, the heart H may be lifted and turned, for example using a sheet of gauze or other material which is placed behind the heart, to expose the left atrial appendage LAA within the opening as shown inFIG.9. After the left atrial appendage LAA is exposed, the jaws18,20of the fastener applicator10are placed around the base of the left atrial appendage LAA by manipulating the shaft12. Once the jaws18,20properly position the fastener22about the base of the left atrial appendage LAA, the jaws18,20are actuated and the fastener22is deployed as described previously.

Although the invention has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred examples, it is to be understood that such detail is solely for that purpose and that the invention is not limited to the disclosed examples, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims. For example, it is to be understood that the present invention contemplates that, to the extent possible, one or more features of any example can be combined with one or more features of any other example.