BACKGROUND OF THE INVENTION

Field of the Invention

The present invention generally relates to surgical fasteners, and more specifically relates to applicator instruments, systems and methods for deploying surgical fasteners.

Description of the Related Art

Hernia is a condition where a small loop of bowel or intestine protrudes through a weak place or defect within the abdominal muscle wall or groin of a patient. This condition commonly occurs in humans, particularly males. Hernias of this type may result from a congenital defect whereby the patient is born with this problem, or may be caused by straining or lifting heavy objects. Heavy lifting may be known to create a large amount of stress upon the abdominal wall and can cause a rupture or tearing at a weak point of the abdominal muscle to create the defect or opening. In any case, the patient may be left with an unsightly bulge of intestinal tissue protruding through the defect, which may result in pain, reduced lifting abilities, and in some cases, impaction of the bowel, or possibly other complications if the flow of blood is cut off to the protruding tissue.

A common solution to the above-described problem may be surgery. During a surgical procedure, the defect is accessed and carefully examined, either through an open incision or endoscopically through an access port such as a trocar. In either case, careful examination is required due to the network of vessels and nerves which exist in the area of a typical defect, which requires a surgeon to conduct a hernia repair with great skill and caution. Within this area can be found vascular structures such as gastric vessels, the external iliac vessels, and the inferior epigastric vessels, as well as reproductive vessels such as the vas deferens extending through the inguinal floor.

Once the surgeon is familiar with the anatomy of a patient, the surgeon carefully places the viscera back into the patient's abdomen through the defect. Repairing the defect can involve closure of the defect with sutures or fasteners but generally involves placing a surgical prosthetic such as a mesh patch over the open defect, and attaching the mesh patch to the abdominal wall or inguinal floor with conventional suture or with surgical fasteners. The mesh patch acts as a barrier and prevents expulsion of bowel through the defect. Suturing of the mesh patch to the inguinal floor can be well suited to open procedures but can be much more difficult and time consuming with endoscopic procedures. With the adoption of endoscopic surgery, endoscopic surgical instruments that apply surgical fasteners can be used. However, the tissue of the inguinal floor may offer special challenges to the surgeon when a needle or fastener is used to penetrate structures such as Cooper's ligament.

At present, there are a variety of surgical instruments and fasteners available for the surgeon to use in an endoscopic or open procedure to attach the mesh patch to the inguinal floor. One of the earliest types of endoscopic surgical instruments used is a surgical stapler. A plurality or stack of these unformed staples may be generally contained within a stapling cartridge in a serial fashion, and may be sequentially advanced or fed within the instrument by a spring mechanism. A secondary valving or feeding mechanism may be employed to separate the distal most staple from the stack, to hold the remainder of the spring loaded stack, and may be used to feed the distal most staples into the staple forming mechanism. Feeding mechanisms of this type are found in U.S. Pat. No. 5,470,010 to Rothfuss et al., and in U.S. Pat. No. 5,582,616, also to Rothfuss et al.

Another hernia mesh attachment instrument uses a helical wire fastener that resembles a small section of spring. Multiple helical wire fasteners may be stored serially within the 5 mm shaft, and may be corkscrewed or rotated into tissue. A load spring may be used to bias or feed the plurality of helical fasteners distally within the shaft. A protrusion extends into the shaft to possibly prevent the ejection of the stack of fasteners by the load spring and may permit passage of a rotating fastener. Instruments and fasteners of these types are found in U.S. Pat. No. 5,582,616 to Bolduc et al., U.S. Pat. No. 5,810,882 to Bolduc et al., and in U.S. Pat. No. 5,830,221 to Stein et al.

Whereas the above surgical instruments may be used for hernia fastening applications, they use a spring mechanism to feed a plurality of fasteners through the surgical instrument. Spring mechanisms typically use a long soft coil spring to push a stack of fasteners through a guide or track within the shaft of the surgical instrument. These types of feeding mechanisms may be generally simple and reliable, but may require an additional secondary valving mechanism or protrusion to separate and feed one fastener from the stack.

Other surgical fasteners may be used for hernia mesh attachment but utilize either a reloadable single shot instrument or a rotary magazine that holds a small number of fasteners. These types of surgical fastening instruments can be found in U.S. Pat. Nos. 5,203,864 and 5,290,297, both to Edward Phillips. These instruments have not gained acceptance by the surgical community, possibly due to their single shot capabilities and the large size of the rotary magazine, which can restrict such an instrument to an open procedure.

Whereas all the above surgical instruments may be used for hernia fastening applications, they either use a spring mechanism to feed the plurality of fasteners through the surgical instrument, or a rotary magazine in lieu of a feeding mechanism. Other types of surgical fasteners may be available, such as surgical clips, and they can utilize feeding mechanisms that do not require the use of a spring to feed the clips distally. A reciprocating feeding mechanism is described in U.S. Pat. Nos. 5,601,573; 5,833,700; and 5,921,997 to Fogelberg et al. The Fogelberg et al. references teach a clip applier with a feeding mechanism that utilizes a reciprocating feed bar to feed a serial stack of clips. A feeder shoe may operably engage with and move with the distally moving feed bar and may slidingly engage with the proximally moving feed bar. Thus, the feeder shoe may index or push the stack of clips distally with the distally moving feed bar and remains stationary relative to the proximally moving feed bar. A valving mechanism may be also required to separate the distal-most clip from the stack and to hold the stack stationary as the distal most clip may be applied onto a vessel. Whereas the Fogelberg et al. references teach a reciprocating feeding mechanism with a single reciprocating member, they do not teach the use of the clip applier in the attachment of hernia mesh, nor do they teach the individual driving or feeding of each clip by a moving member.

Another fastener feeding mechanism that uses reciprocation is that disclosed in U.S. Pat. No. 4,325,376 to Klieman et al. A clip applier that stores a plurality of clips in a serial fashion within a clip magazine is disclosed. The clips are in a stack wherein the proximal most clip may be pushed or fed distally by a pawl that may be ratcheted or indexed distally by a reciprocating member or ratchet blade with each actuation of the instrument. As the pawl indexes distally, it can push the stack of clips distally. A secondary valving mechanism may be also described. Thus, the feeding mechanism of Klieman et al. teaches the use a single reciprocating member and pawl to push or feed the stack of clips distally, and may require a secondary valving mechanism to feed the distal most clip.

U.S. Pat. No. 3,740,994 to DeCarlo Jr. describes a novel reciprocating feeding mechanism that may index a plurality of staples or clips, and may ready them for discharge by reciprocating one of a pair of opposing leaf spring assemblies. The staples reside serially within a guide rail with a fixed leaf spring assembly extending into the plane of the guide rail. A reciprocating leaf spring assembly may opposedly extend inwardly towards the fixed leaf spring assembly. As the reciprocating leaf spring assembly moves distally, each of individual leaf springs of the assembly may engage a staple and move it distally. The distally moving staples deflect the local individual leaf springs of the fixed leaf spring assembly, and the deflected leaf springs may return to the un-deflected position after passage of the staple. As the moving leaf spring assembly moves proximally, the leaf springs of the fixed leaf spring assembly hold the staples stationary and prevent proximal movement thereof. A secondary guide rail and valving mechanism may be provided to separate a single staple from the stack for forming and can hold the stack of staples stationary as the single clip is formed.

Additionally, similar feeding mechanisms are disclosed in U.S. Pat. No. 4,478,220 to DiGiovanni et al. and U.S. Pat. No. 4,471,780 to Menges et al. Both of these related patents teach a reciprocating feeding mechanism that uses one fixed member and one reciprocating member to feed or index a plurality of clips distally. Angled flexible fingers may be hingedly attached to the reciprocating member and operatively engage the clips when moving distally, and slidingly engage with the clips when moving proximally. The angled flexible fingers within the fixed member deflect out of the way when the clips move distally and spring up to stop proximal movement of the clip after the clip has passed. A secondary valving mechanism is also disclosed.

Commonly assigned U.S. Patent Application Publication No. 2002/0068947, the disclosure of which is hereby incorporated by reference herein, teaches a device for delivering a plurality of individual surgical fasteners. In one embodiment, the delivery device includes a drive mechanism having distal and proximal ends. The drive mechanism has a moving member and a fixed opposing member, whereby the moving member is moveable proximally and distally with respect to the delivery device. The moving member has a sharpened distal end for piercing tissue. The device includes at least one surgical fastener located between the first and the second members. Each of the at least one surgical fasteners has a proximal end and a distal end. The device also has an actuator having at least two sequential positions. A first position for moving the moving member distally and piercing tissue, and a second position for moving the moving member proximally, thereby deploying the distal end of the fastener.

Tacks for fixing meshes used laparoscopically have generally been made of metal, such as stainless steel, nitinol, or titanium. The metal tacks were necessary to provide for sufficient holding strength, penetration of various prosthetic meshes, and for ease of manufacture. Until recently, there were no absorbable tacks available on the market, and surgeons could only use absorbable sutures in order to provide a fixation means that did not permanently stay in the body. However, using sutures is exceedingly difficult for laparoscopic procedure, and so they are generally not used unless the repair is done in an open fashion. With surgical trends leading to more minimally invasive techniques with minimum foreign body accumulation, an absorbable tack with minimum profile that can be applied laparoscopically is needed.

In spite of the above advances, there remains a need for further improvements. In particular, there remains a need for surgical fasteners having a minimum profile, surgical fasteners that may be applied laparoscopically, and surgical fasteners that are absorbable.

SUMMARY OF THE INVENTION

In one embodiment, the present invention discloses an applicator instrument and methods for consistently deploying surgical fasteners. In one embodiment, the applicator instrument is used to hold a prosthetic device such as surgical mesh in place over tissue. In one embodiment, the applicator instrument includes a mechanism for positioning a surgical fastener in line with a firing rod. The applicator instrument preferably includes a firing system that initially advances the firing rod toward the surgical fastener at a first speed. In one embodiment, energy may be stored in the firing system as the firing rod is advanced or piloted toward the surgical fastener. The firing system desirably engages the surgical fastener with the firing rod while maintaining the surgical fastener in a stationary position. The firing system preferably releases the stored energy to advance the firing rod at a second speed that is greater than the first speed to deploy the surgical fastener into tissue. In one embodiment, one surgical fastener is dispensed during one cycle of the firing system. A plurality of surgical fasteners may be dispensed for securing a prosthesis such as a surgical mesh to tissue.

In one embodiment, an applicator instrument for dispensing surgical fasteners preferably includes a housing, and an elongated shaft extending from the housing having a proximal end coupled with the housing and a distal end remote therefrom. The applicator instrument desirably includes a firing system for dispensing surgical fasteners from the distal end of the elongated shaft. The firing system preferably includes a firing rod disposed in the elongated shaft, and desirably has a firing cycle with a first stage for advancing the firing rod toward the distal end of the elongated shaft at a first rate of speed and a second stage for advancing the firing rod toward the distal end of the elongated shaft at a second rate of speed that is greater than the first rate of speed.

In one embodiment, a distal end of the firing rod includes an insertion fork. The applicator instrument is adapted to slowly pilot the insertion fork into a lead surgical fastener followed by quick firing of the surgical fastener through a prosthetic device and into tissue. Prior art devices rapidly advance a pushing element in one motion through a fastener in a hammer-like manner while continuing to drive the fastener into tissue, or slowly engage a fastener at the same rate for slowly driving the fastener into tissue. The first type of prior art device is limited in its ability to engage the fastener in a secure manner to assure the fastener's proper insertion into tissue. The first “hammer-like” prior art device may also damage the surgical fastener due to impact force or may require the use of a massive fastener adapted to withstand impact forces. The second type of prior art device does not advance the fastener fast enough to avoid tissue tenting and to enable proper tissue penetration. Both of these prior art approaches do not lend themselves to consistent and repeatable fastener penetration into tissue. In one embodiment, the present invention solves these limitations by slowly piloting an insertion fork into a lead surgical fastener, which assures proper engagement of the insertion fork with the surgical fastener. After proper engagement, the present invention also provides for quick firing of the surgical fastener through a prosthetic device and into tissue. As a result, each surgical fastener is preferably inserted the same way regardless of the speed of a user's trigger squeeze.

In one embodiment, the distal end of the firing rod is coupled with at least one of the surgical fasteners during the first stage of the firing cycle, and the distal end of the firing rod dispenses the at least one of the surgical fasteners from the distal end of the elongated shaft during the second stage of the firing cycle. The firing system may include an energy storing element such as a firing spring coupled with the firing rod, whereby the firing system is adapted to store energy in the firing spring before the second stage of the firing cycle and transfer the stored energy from the firing spring to the firing rod during the second stage of the firing cycle. In certain embodiments, the energy storing element may also include a pneumatic device, a hydraulic device and/or a compressed gas device.

In one embodiment, the applicator instrument includes an actuator movable between a first position and a second position for activating the firing system. The actuator may be a squeezable trigger that activates the firing system. In one embodiment, the firing spring is at least partially compressed prior to the first stage of the firing cycle, and the firing rod advances distally at a rate that is proportional to movement of the actuator during the first stage of the firing cycle. The firing spring is preferably compressible for storing energy therein as the actuator moves from the first position to the second position. The energy stored in the firing spring is released during the second stage of the firing cycle for rapidly driving the firing rod toward the distal end of the elongated shaft. Although many of the embodiments disclosed herein refer to a “firing spring”, it is contemplated that other energy storing devices, such as those disclosed above may be used and still fall within the scope of the present invention.

In one embodiment, the firing system preferably includes a release latch that constrains the firing rod from moving toward the distal end of the elongated shaft after the first stage of the firing cycle and before the second stage of the firing cycle. At a preferred stage of the firing cycle, and preferably after energy is stored in the firing system, the release latch desirably releases the firing rod for moving distally.

In one embodiment, the applicator instrument may include an advancer coupled with the actuator and extending through the elongated shaft for advancing the surgical fasteners toward the distal end of the elongated shaft. The advancer is preferably adapted to move toward the distal end of the elongated shaft as the actuator moves from the first position to the second position. The advancer is preferably adapted to move toward the proximal end of the shaft as the actuator moves from the second position to the first position. The advancer desirably includes a plurality of advancer tabs projecting toward a distal end of the advancer, whereby each advancer tab is adapted to engage one of the surgical fasteners for urging the surgical fasteners toward the distal end of the elongated shaft.

In one embodiment, the surgical fasteners are disposed within the elongated shaft for being urged toward the distal end of the elongated shaft by the advancer. In one embodiment, a most distal one of the surgical fasteners is engageable by the staging assembly for aligning the most distal one of the surgical fasteners with the distal end of the firing rod. In one embodiment, the distal end of the firing rod includes an insertion fork having spaced tines that are adapted to engage the most distal one of the surgical fasteners.

In one embodiment, a surgical fastener includes a first leg having a distal end with a first insertion tip, a proximal end, and a first insertion tool seating surface located adjacent the first insertion tip. The surgical fastener preferably includes a second leg having a distal end with a second insertion tip, a proximal end, and a second insertion tool seating surface located adjacent the second insertion tip. The surgical fastener also desirably includes a bridge connecting the proximal ends of the first and second legs for forming a closed proximal end of the surgical fastener. In one embodiment, tines of an insertion fork are preferably seatable against the first and second insertion tool seating surfaces of the surgical fastener for applying an insertion force upon the surgical fastener at a location that is closer to the distal end of the surgical fastener than the proximal end of the surgical fastener.

In one embodiment, an applicator instrument may include a lockout system coupled with the firing system for preventing operation of the firing system after all of the surgical fasteners have been dispensed. In one embodiment, the lockout system locks an actuator or trigger in a closed position after all of the surgical fasteners have been dispensed.

In one embodiment, an applicator instrument for dispensing surgical fasteners includes a housing having a handle section and a trigger, and an elongated shaft for dispensing the surgical fasteners. The elongated shaft includes a proximal end coupled with the housing and a distal end remote therefrom. The elongated shaft may include a surgical fastener delivery conduit extending therethrough for delivering or dispensing the surgical fasteners from the distal end of the elongated shaft. The applicator instrument preferably includes a firing system actuatable by the trigger, whereby the firing system includes a firing rod and an energy storing assembly coupled with the firing rod. In one embodiment, the firing system desirably has a firing cycle including a first stage for moving the firing rod toward the distal end of the elongated shaft at a first speed and a second stage for transferring energy from the energy storing assembly to the firing rod for driving the firing rod toward the distal end of the elongated shaft at a second speed that is greater than the first speed. In one embodiment, energy may be stored in the energy storing assembly during the initial piloting stage when the firing rod moves forward at the first speed.

In one embodiment, the applicator instrument may include a staging assembly disposed within the elongated shaft for aligning the surgical fasteners with a distal end of the firing rod. The surgical fasteners are preferably advanced through an elongated conduit in the elongated shaft and toward the distal end of the elongated shaft. The applicator instrument may include an advancer coupled with the firing system for incrementally advancing the surgical fasteners toward the distal end of the elongated shaft each time the trigger is squeezed. In one embodiment, the firing rod preferably moves distally as the trigger is squeezed from an open position to a closed position, and the firing rod moves proximally as the trigger returns from the closed position to the open position.

In one embodiment, a method of dispensing surgical fasteners includes providing an applicator instrument having a housing, an elongated shaft projecting from the housing, and a firing system including a firing rod for dispensing surgical fasteners from a distal end of the elongated shaft. The method preferably includes aligning a first surgical fastener with a distal end of the firing rod, advancing the distal end of the firing rod toward the first surgical fastener at a first speed for engaging the surgical fastener, and after the firing rod advancing step and while constraining the firing rod from moving toward the distal end of the elongated shaft, storing energy in the firing system. The method desirably includes releasing the firing rod for distal movement and transferring the stored energy to the firing rod for driving the firing rod distally at a second speed that is greater than the first speed so as to dispense the first or lead surgical fastener from the distal end of the elongated shaft.

In one embodiment, the firing system desirably includes a compressible firing spring coupled with the firing rod, and an actuator coupled with the firing spring for selectively compressing the firing spring for storing energy in the firing system. In one embodiment, the energy for advancing the firing rod is stored in a spring. In one embodiment, the spring is a firing spring that is preferably pre-loaded or pre-compressed prior to actuation of the applicator instrument.

In one embodiment, the applicator instrument includes a lockout mechanism to prevent operation of the applicator instrument when no more surgical fasteners are available (e.g. all of the surgical fasteners have been dispensed). In one embodiment, the lockout mechanism preferably locks the trigger in a closed position when the device is empty. The lockout mechanism may also include a mechanical or electronic counter that displays how many surgical fasteners have been dispensed and/or how many surgical fasteners remain available.

In one embodiment, the distal end of the applicator instrument, such as the distal end of the elongated shaft, includes one or more markings for orientation. The distal end of the elongated shaft may also include one or more features provided on the distal tip to assist with device orientation and/or to capture one or more mesh strands. In one embodiment, the applicator instrument includes one or more protuberances to capture one or more strands of mesh.

In one embodiment, a surgical fastener includes a first leg having a distal end, a proximal end and a first insertion tip at the distal end of the first leg. The surgical fastener preferably includes a second leg having a distal end, a proximal end, and a second insertion tip at the distal end of the second leg. A bridge desirably connects the proximal ends of the first and second legs for forming a closed end of the surgical fastener. The first insertion tip preferably includes a first insertion tool seating surface and the second insertion tip preferably includes a second insertion tool seating surface.

In one embodiment, the first and second legs extend along respective longitudinal axes, and the first and second insertion tips are skewed or angulated outwardly relative to the respective longitudinal axes of the first and second legs. As a result, in one embodiment, the spacing between the insertion tips is greater than the spacing between the first and second legs, which may enhance the capture of strands or fibers between the legs. In one embodiment, at least one of the first and second insertion tips includes a blunt distal piercing point. In one embodiment, both of the first and second insertion tips include blunt distal piercing points.

In one embodiment, the first insertion tip includes a proximal end with the first insertion tool seating surface, and the second insertion tip includes a proximal end including the second insertion tool seating surface. In one embodiment, the first insertion tool seating surface is closer to the distal end of the first leg than the proximal end of the first leg, and the second insertion tool seating surface is closer to the distal end of the second leg than the proximal end of the second leg. The first and second insertion tool seating surfaces preferably face toward the proximal ends of the respective first and second legs and are adapted to be engaged by the distal end of an insertion tool, such as the distal ends of tines or an insertion fork.

In one embodiment, the first insertion tool seating surface includes an opening facing toward the proximal end of the first leg, and the second insertion tool seating surface includes a second opening facing toward the proximal end of the second leg. The openings in the insertion tool seating surfaces may be blind openings that are closed at one end (e.g. at the distal end). In one embodiment, the first insertion tool seating surface includes a first aperture that extends completely through the first insertion tip, and the second insertion tool seating surface includes a second aperture that extends completely through the second insertion tip.

In one embodiment, the first leg of a surgical fastener preferably includes a first alignment guide extending between the proximal end of the first leg and the first insertion tool seating surface, and the second leg preferably includes a second alignment guide extending between the proximal end of the second leg and the second insertion tool seating surface. The first alignment guide on the first leg is preferably in substantial alignment with the first insertion tool seating surface, and the second alignment guide on the second leg is preferably in substantial alignment with the second insertion tool seating surface. The first and second alignment guides may include ribs extending between the distal and proximal ends of the legs, grooves extending between the distal and proximal ends of the legs, or a combination of ribs and grooves.

In one embodiment, the first and second insertion tips have distal ends that are staggered from one another, which may reduce the amount of force required to anchor the surgical fastener in tissue. In one embodiment, the bridge adjacent the proximal end of the surgical fastener defines a third insertion tool seating surface engageable by a surface on an insertion tool.

In one embodiment, the first leg of a surgical fastener includes a first barb projecting toward the proximal end of the first leg, and the second leg of the surgical fastener includes a second barb projecting toward the proximal end of the second leg, whereby the first and second barbs are staggered from one another. In one embodiment, the first and second barbs on the respective first and second legs project outwardly away from one another. In another embodiment, the first and second barbs on the respective first and second legs project inwardly toward one another.

In one embodiment, a surgical fastener for anchoring prosthetic devices to tissue includes a first leg having a distal end, a proximal end, a first alignment guide extending between the distal and proximal ends of the first leg, and a first insertion tip at the distal end of the first leg. The surgical fastener desirably includes a second leg having a distal end, a proximal end, a second alignment guide extending between the distal and proximal ends of the second leg, and a second insertion tip at the distal end of the second leg. The surgical fastener preferably includes a bridge connecting the proximal ends of the first and second legs for forming a closed end of the surgical fastener.

In one embodiment, the first insertion tip has a proximal end with a first insertion tool seating surface and the second insertion tip has a proximal end with a second insertion tool seating surface. The first and second insertion tool seating surfaces may include convex surfaces facing toward the proximal ends of the first and second legs, concave surfaces facing toward the proximal ends of the first and second legs, openings facing toward the proximal ends of the first and second legs, blind vias facing toward the proximal ends of the first and second legs, and/or apertures extending through the first and second insertion tips.

In one embodiment, the first and second alignment guides are selected from the group of alignment guides including ribs extending between the distal and proximal ends of the legs, and grooves extending between the distal and proximal ends of the legs. The first and second alignment guides are substantially aligned with the respective first and second insertion tool seating surfaces. In one embodiment, the first and second seating surfaces are desirably closer to the distal end of the surgical fastener than the proximal end of the surgical fastener.

In one embodiment, an applicator instrument for dispensing surgical fasteners includes a housing, and an elongated shaft extending from the housing, the elongated shaft having a proximal end, a distal end, and a longitudinal axis extending between the proximal and distal ends. The applicator instrument desirably includes a firing rod disposed inside the elongated shaft and that is moveable within a first plane between a retracted position and an extended position. The elongated shaft preferably includes an advancer disposed inside the elongated shaft that is moveable within a second plane between a retracted position and an extended position. The applicator instrument preferably includes a staging assembly located adjacent the distal end of the elongated shaft that is adapted to align surgical fasteners with a distal end of the firing rod. The staging assembly is preferably held below the second plane by the advancer when the advancer is in the extended position, and the staging assembly is preferably adapted to move into at least partial alignment with the distal end of the firing rod when the advancer moves toward or is in the retracted position.

The applicator instrument preferably includes a plurality of surgical fasteners disposed within the elongated shaft, whereby the advancer is adapted to move the surgical fasteners one position toward the distal end of the elongated shaft each time the advancer moves from the retracted position to the extended position. In one embodiment, the plurality of surgical fasteners desirably include a lead surgical fastener located adjacent the distal end of the elongated shaft and a series of trailing surgical fasteners located between the lead surgical fastener and the proximal end of the elongated shaft.

In one embodiment, the advancer includes a plurality of advancer tabs whereby each of the advancer tabs is preferably adapted to engage one of the surgical fasteners for urging the surgical fasteners toward the distal end of the elongated shaft as the advancer moves from the retracted position to the extended position. In one embodiment, the advancer tabs project toward the distal end of the elongated shaft. In one embodiment, the advancer is moveable into the extending position for moving the lead surgical fastener into contact with the staging assembly.

In one embodiment, a floor of the elongated shaft includes a plurality of anti-backup tabs, whereby the anti-backup tabs are adapted to prevent the surgical fasteners in the elongated shaft from moving toward the proximal end of the elongated shaft. In one embodiment, the anti-backup tabs project toward the distal end of the elongated shaft.

In one embodiment, the advancer urges the lead surgical fastener into contact with the staging assembly, and the staging assembly is adapted to lift the lead surgical fastener into substantial alignment with the distal end of the firing rod as the advancer returns to the retracted position.

In one embodiment, the elongated shaft includes at least one guide surface adapted to engage and/or contact the firing rod for guiding distal and proximal movement of the firing rod. In one embodiment, the at least one guide surface includes a pair of opposing guide flanges adapted to engage opposites sides of the firing rod for guiding distal and proximal movement of the firing rod.

In one embodiment, the distal end of the firing rod includes an insertion tool, such as an insertion fork, having a first tine with a distal end adapted to engage the first insertion tool seating surface, and a second tine having a distal end adapted to engage the second insertion tool seating surface. In one embodiment, the bridge of the surgical fastener has a proximal face defining a third insertion tool seating surface, and the insertion tool includes a distal surface extending between the proximal ends of the first and second tines adapted to engage the third insertion tool seating surface.

In one embodiment, an applicator instrument for dispensing surgical fasteners includes a housing, an elongated shaft extending from the housing, the elongated shaft including a proximal end and a distal end remote therefrom, and a plurality of surgical fasteners disposed within the elongated shaft for being dispensed from the distal end of the elongated shaft. The applicator instrument preferably includes an advancer disposed inside the elongated shaft that is moveable between the proximal and distal ends of the elongated shaft, whereby the advancer is adapted to shift the surgical fasteners one position closer to the distal end of the elongated shaft each time the advancer moves distally. The applicator instrument preferably includes a firing rod disposed inside the elongated shaft and overlying the advancer, the firing rod being moveable between the proximal and distal ends of the elongated shaft. The applicator instrument desirably includes a staging assembly located adjacent the distal end of the elongated shaft that is adapted to receive a leading one of the surgical fasteners from the advancer as the advancer moves distally and to shift the received leading surgical fastener into substantial alignment with a distal end of the firing rod when the advancer moves proximally.

In one embodiment, the distal end of the firing rod is adapted to move distally at a first rate of speed for engaging the leading surgical fastener, and then to move distally at a second rate of speed that is faster than the first rate of speed for dispensing the leading surgical fastener from the distal end of the elongated shaft.

In one embodiment, the first leg of the surgical fastener includes a first alignment guide extending between the proximal end of the first leg and the first insertion tool seating surface, and the second leg of the surgical fastener includes a second alignment guide extending between the proximal end of the second leg and the second insertion tool seating surface. The first alignment guide on the first leg is preferably in substantial alignment with the first insertion tool seating surface and the second alignment guide on the second leg is preferably in substantial alignment with the second insertion tool seating surface. In one embodiment, the first alignment guide includes a first rib extending between the distal and proximal ends of the first leg, and the second alignment guide includes a second rib extending between the distal and proximal ends of the second leg, whereby the first and second tines at the distal end of the firing rod have opposing inner surfaces with opposing grooves adapted to engage the first and second ribs on the respective first and second legs for engaging the surgical fastener with the insertion tool.

In one embodiment, a method of dispensing a surgical fastener includes providing an applicator instrument having a housing and an elongated shaft extending from the housing, the elongated shaft including a proximal end and a distal end remote therefrom, and providing surgical fasteners in the elongated shaft for being dispensed one at a time from the distal end of the elongated shaft. The method preferably includes advancing the surgical fasteners within a first plane toward the distal end of the elongated shaft. After advancing a leading one of the surgical fasteners to a location adjacent the distal end of the elongated shaft, the leading surgical fastener is preferably shifted from the first plane into a second plane in which the leading surgical fastener is substantially aligned with a distal end of a firing rod. The firing rod is then desirably moved distally for engaging the leading surgical fastener with the firing rod and dispensing the leading surgical fastener from the distal end of the elongated shaft.

In one embodiment, the method includes loading the surgical fasteners in the elongated shaft. In one embodiment, the step of moving the firing rod distally includes a first distal movement stage during which the firing rod moves distally at a first rate of speed for engaging the leading surgical fastener, and a second distal movement stage that follows the first distal movement stage during which the firing rod moves distally at a second rate of speed for dispensing the leading surgical fastener from the distal end of the elongated shaft, whereby the second rate of speed is greater than the first rate of speed.

In one embodiment, after the advancing step, and while constraining the firing rod from moving toward the distal end of the elongated shaft, energy is stored in the firing system. The firing rod may later be unconstrained or released so that it is able to move in the distal direction and the stored energy may be transferred to the firing rod for driving the firing rod distally at the second speed that is greater than the first speed for dispensing the first surgical fastener from the distal end of the elongated shaft.

In one embodiment, the firing system includes an energy storing element such as a compressible firing spring coupled with the firing rod, and an actuator coupled with the firing spring for selectively compressing the firing spring so as to store energy in the firing system.

In one embodiment, a method of affixing a prosthesis to tissue includes providing an applicator instrument for dispensing surgical fasteners having a housing, an elongated shaft extending from the housing, the elongated shaft having a proximal end coupled with the housing and a distal end remote therefrom, and a firing system for dispensing surgical fasteners from the distal end of the elongated shaft. The firing system preferably includes a firing rod disposed in the elongated shaft, the firing system having a firing cycle with a first stage for advancing the firing rod toward the distal end of the elongated shaft at a first rate of speed and a second stage for advancing the firing rod toward the distal end of the elongated shaft at a second rate of speed that is greater than the first rate of speed. The method preferably includes positioning a prosthesis, such as a surgical mesh, over tissue, and operating the applicator instrument for dispensing at least one of the surgical fasteners from the distal end of the elongated shaft for affixing the prosthesis to the tissue. In one embodiment, a plurality of surgical fasteners may be dispensed for affixing the prosthesis to the tissue.

In one embodiment, a firing system for an applicator instrument adapted to dispense surgical fasteners includes a housing, an elongated shaft extending from the housing, a firing rod disposed within the elongated shaft, a firing rod release engageable with the firing rod for preventing distal movement of the firing rod during at least one stage of a firing cycle, a trigger mounted to the housing, and a firing spring having a first end connected with the firing rod and a second end adapted for being sequentially coupled and decoupled from the trigger during the firing cycle. In one embodiment, the firing cycle desirably includes an initial stage in which the trigger is open and decoupled from the firing spring and the firing spring is at least partially compressed, and a piloting stage during which the firing rod release is disengaged from the firing rod for enabling distal movement of the firing rod. The trigger is preferably compressible a first distance for coupling the trigger with the firing spring for moving the at least partially compressed firing spring distally, which, in turn, moves the firing rod distally at a first rate of speed that is proportional to the movement of the trigger. In one embodiment, an energy storing element such as a pneumatic or hydraulic device may be used in place of or in combination with the firing spring.

In one embodiment, the firing cycle includes, after the piloting stage, an energy storing stage in which the firing rod release engages the firing rod for preventing distal movement of the firing rod, and the trigger is further moveable a second distance for further compressing and storing energy in the firing spring. The firing cycle preferably includes a firing stage in which the firing rod release disengages from the firing rod so that the firing rod is free to move toward the distal end of the elongated shaft and the firing spring transfers the energy stored therein to the firing rod for rapidly advancing the firing rod toward the distal end of the elongated shaft at a second rate of speed that is greater than both the first rate of speed and the movement of the trigger.

In one embodiment, the firing cycle includes a decoupling stage during which the trigger is further compressible a third distance for decoupling the trigger from the firing spring whereupon the firing rod is free to move toward the proximal end of the elongated shaft.

In one embodiment, the firing system includes an advancer disposed within the elongated shaft and that is moveable in proximal and distal directions along the elongated shaft. The firing cycle preferably includes, after the firing stage, a surgical fastener advancing stage during which the trigger is further compressible a fourth distance for moving the advancer toward the distal end of the elongated shaft so as to move the surgical fasteners toward the distal end of the elongated shaft.

In one embodiment, the firing cycle preferably includes, after the surgical fastener advancing stage, a retraction stage during which the trigger moves from a compressed position to the open position of the initial stage for moving the advancer in a proximal direction.

In one embodiment, the firing system preferably includes a spring block disposed within the housing and engageable with a proximal end of the firing spring. The spring block is preferably adapted to move proximally and distally along the longitudinal axis defined by the elongated shaft. In one embodiment, during the energy storing stage, the trigger is coupled with the spring block for moving the spring block distally, which, in turn, further compresses the firing spring.

In one embodiment, the firing system includes a primary latch coupled with the trigger. The primary latch is preferably adapted to couple the trigger with the spring block during the piloting, energy storing, and firing stages, and decouple the trigger from the spring block during the decoupling, surgical fastener advancing, and retraction stages. In one embodiment, at the beginning of the firing stage, the spring block contacts the firing rod release for disengaging the firing rod release from the firing rod so that the firing rod may move distally.

In one embodiment, a firing system for a surgical fastener applicator instrument includes a housing and an elongated shaft extending from the housing. The firing system desirably includes a firing rod disposed within the elongated shaft and being moveable proximally and distally along a longitudinal axis, a firing spring block disposed within the housing and being adapted to move in proximal and distal directions along the longitudinal axis, and a firing spring having a distal end connected with the firing rod and a proximal end engageable with the firing spring block. The firing system preferably includes a trigger mounted to the housing for driving the firing system, whereby the trigger includes a primary latch for sequentially coupling and decoupling the trigger from the firing spring block during a firing cycle.

In one embodiment, the firing cycle preferably includes an initial stage in which the trigger is open, the trigger is decoupled from the firing spring block, and the firing spring is at least partially compressed. The firing system preferably includes a piloting stage in which the firing rod is free to move distally, and the trigger is compressible a first distance for coupling the trigger with the firing spring block so as to move the at least partially compressed firing spring distally, which, in turn, moves the firing rod distally at a first rate of speed that is proportional to the movement of the trigger. In one embodiment, the compression level of the firing spring remains unchanged during the piloting stage. In one embodiment, the firing spring may be compressed during the piloting stage.

In one embodiment, the firing cycle includes, after the piloting stage, an energy storing stage in which the trigger is further compressible a second distance for further compressing and/or storing energy in the firing spring while the firing rod release engages the firing rod for preventing distal movement of the firing rod.

The firing cycle preferably includes, after the energy storing stage, a firing stage in which the firing rod release disengages from the firing rod so that the firing rod is free to move toward the distal end of the elongated shaft and the firing spring transfers the energy stored therein to the firing rod for rapidly advancing the firing rod toward the distal end of the elongated shaft at a second rate of speed that is greater than the first rate of speed.

The firing cycle preferably includes, after the firing stage, a decoupling stage during which the trigger is further compressible a third distance for decoupling the trigger from the firing spring and the firing rod so that said firing rod may move proximally.

In one embodiment, the firing system includes an advancer disposed within the elongated shaft. The advancer is preferably moveable between the proximal and distal ends of the elongated shaft for moving surgical fasteners toward the distal end of the elongated shaft. The firing cycle may include, after the firing stage, a surgical fastener advancing stage during which the trigger is further compressible a fourth distance for moving the advancer toward the distal end of the elongated shaft, which, in turn, moves the surgical fasteners toward the distal end of the elongated shaft.

In one embodiment, the firing system preferably includes a spring block disposed within the housing. The spring block is preferably adapted to move proximally and distally along the longitudinal axis. The spring block preferably engages the firing spring, and during the energy storing stage, the trigger is coupled with the spring block for moving the spring block distally, which, in turn, compresses the firing spring. The firing system may also include a primary latch coupled with the trigger. The primary latch is preferably adapted to couple the trigger with the spring block during the piloting, energy storing, and firing stages, and decouple the trigger from the spring block during the decoupling, surgical fastener advancing, and retraction stages.

In one embodiment, a method of dispensing surgical fasteners from an applicator instrument includes providing a housing, an elongated shaft extending from the housing, a firing rod disposed within the elongated shaft that is moveable proximally and distally for dispensing surgical fasteners from the distal end of the elongated shaft, a trigger for operating the applicator instrument, and an energy storing element disposed between the trigger and the firing rod. The method preferably includes compressing the trigger for piloting the firing rod toward the distal end of the elongated shaft at a first rate of speed, and after piloting the firing rod, preventing the firing rod from moving distally while further compressing the trigger for storing energy in the energy storing element. The method preferably includes releasing the firing rod for distal movement, and transferring the energy stored in the energy storing element to the firing rod for moving the firing rod toward the distal end of the elongated shaft at a second rate of speed that is greater than the first rate of speed. In one embodiment, during the piloting stage, the firing rod moves distally at a first rate of speed that is proportional to the movement of the trigger.

In one embodiment, the energy storing element is a firing spring disposed between the trigger and the firing rod. In one embodiment, the firing spring is at least partially compressed before piloting the firing rod toward the distal end of the elongated shaft and the firing spring has a compression level that does not change during the piloting step. As noted herein, the energy storing element may also include a pneumatic device, a hydraulic device, a compressed gas device, or combinations thereof.

In one embodiment, the method includes providing a plurality of surgical fasteners within the elongated shaft, and providing an advancer disposed within the elongated shaft. The advancer is preferably coupled with the trigger and is adapted to move toward the distal end of the elongated shaft when the trigger is compressed and move toward the proximal end of the elongated shaft when the trigger is opened. The method preferably includes compressing the trigger for moving the advancer toward the distal end of the elongated shaft, whereby the distally moving advancer shifts each of the surgical fasteners one position closer to the distal end of the elongated shaft. In one embodiment, the trigger may not return to the open position until it is completely squeezed to the closed position.

The applicator instrument may be made in various lengths and diameters. Shorter lengths may be more suitable for open surgical procedures. In one embodiment, the diameter of the shaft of the applicator instrument is preferably between about 3-10 mm, and more preferably between about 3-5 mm. In one embodiment, the applicator instrument includes more than one surgical fastener and may be pre-loaded with a plurality of fasteners such as 10, 25, 100 or more surgical fasteners. In one embodiment, the applicator instrument is pre-loaded with 10 surgical fasteners for open procedures. In one embodiment, the applicator instrument is pre-loaded with 30 surgical fasteners for standard laparoscopic procedures. In one embodiment, the surgical fasteners may be housed in cartridges for easy loading and/or re-loading. In certain embodiments, the applicator instrument may include a stay suture device as part of the handle, or a device/handle that dispenses a skin adhesive such as the tissue adhesive sold under the trademark Dermabond™ for use for trocar wound closure.

In one embodiment, a surgical fastener preferably has a very small profile, may be semi-rigid, and may be fully resorbable. The resorbable nature of the surgical fastener preferably decreases chronic pain caused by permanent fixation. In addition, the low profile of the surgical fastener reduces adhesions of the viscera. As is well known to those skilled in the art, it is very common to see excessive adhesions caused by permanent tackers during re-ops.

In one embodiment, a surgical fastener provides two points of fixation with a connecting back span extending between the two points of fixation so as to spread the tissue holding forces over a greater area. The span between the two points of fixation makes it possible to span the tack across the edge of a mesh, which minimizes exposure of tissue to mesh ends that may be the source of tissue irritation.

In one embodiment, an applicator instrument deploys one or more soft tissue surgical fasteners. The surgical fasteners provide low profile soft tissue fixation of prosthetic materials onto the human body. In one embodiment, the applicator instrument provides for tension-free laparoscopic hernia repair using mesh. In one embodiment, a prosthetic mesh is placed over an abdominal defect and attached to tissue with either permanent or resorbable surgical fasteners. In one embodiment, the surgical fasteners are made of relatively soft materials such as plastic or absorbable polymers.

The present invention provides a number of benefits. In one embodiment, male features on a surgical fastener mate with female features on an inserter device, which reduces the cost for molding the surgical fasteners. In one embodiment, pins or tines on an insertion device provide rigidity during insertion of the surgical fastener and leaves less absorbable mass in tissue as compared with tack systems and methods that do not use inserter pins or tines for stiffening.

In one embodiment, the surgical fasteners have rounded proximal ends. Specifically, each surgical fastener has a connecting bridge or back span at the proximal end of the surgical fastener that is rounded and results in a very low profile after insertion into tissue. The low profile design and small diameter of the surgical fastener results in the surgical fastener having the appearance of a suture stitch once the surgical fastener is implanted. The lower profile also preferably reduces the possibility of forming adhesions in the body.

In one embodiment, surgical fasteners have insertion pin holes or recesses formed in the proximal portion of each insertion tip of the surgical fasteners. The insertion pin holes or recesses are preferably located directly over the center of each insertion tip. As a result, the insertion pin holes or recesses are substantially aligned with the insertion tip to avoid tip bending and to direct forces for insertion directly behind each of the penetrating insertion tips.

In prior art fasteners having a single head, the single head may fall through the large pores of the prosthetic mesh. In one embodiment, surgical fasteners of the present invention have a connecting back span or bridge between two insertion tips. The connecting back span or bridge makes the surgical fastener more compatible for use with large pore surgical prosthetic meshes.

In one embodiment, surgical fasteners have blind holes that are filled by metal inserters, probes, or tines during application. The metal inserters preferably provide rigidity to the surgical fastener during insertion, allowing the surgical fastener itself to be made of a softer material, such as an absorbable polymer. In another embodiment, rigid inserters, probes or tines support the tips and/or legs of the surgical fastener during anchoring into tissue.

In one embodiment, surgical fasteners have lead-in channels that are aligned with blind holes or tool seating surfaces. The lead-in channels are axially open on at least one side, which enables less material to be used for forming the surgical fasteners, and which provides a space for tissue in-growth to maximize fixation strength.

In one embodiment, surgical fasteners have staggered tips, which preferably reduce the necessary penetration force by staggering the peak forces encountered during insertion. In one embodiment, surgical fasteners have staggered barbs improve anchoring in tissue by requiring greater pull out forces.

In one embodiment, surgical fasteners have barbs set out of plane from each other, which increase the force necessary for pull out of the surgical fasteners. In one embodiment, surgical fasteners have insertion tips with through openings extending therethrough. The through openings are preferably adapted to receive one or more needles for needle-assisted insertion.

In one embodiment, surgical fasteners have one or more barbs with “living hinge” features. The living hinges enable the barbs to collapse easily during insertion but flare outwardly during attempts to remove the surgical fasteners.

In one embodiment, the pointed insertion tips of the surgical fasteners are cut or have defined chisel points, which enable the insertion tips to cut during insertion, thereby improving the ability of the surgical fasteners to penetrate difficult materials such as GORE® dual mesh. Insertion tips having compound cut or chiseled angles may also be used to allow for stronger, yet shorter tip designs.

In one embodiment, surgical fasteners may have conical-shaped insertion tips that create a puncture rather than a cut, thereby improving holding force. Although the present invention is not limited by any particular theory of operation, it is believed that conical-shaped insertion tips create only a single point of stress concentration, whereby the section of the surgical fastener that follows must expand the hole radially. It is believed that this may make it harder for the rest of the surgical fastener to make it through the hole, but may potentially increase retention forces by making a tighter hole.

In one embodiment, a surgical fastener includes a pair of spaced insertion points having internally facing barbs. The internally facing barbs desirably protect the barbs from external forces, and make the surgical fasteners easier to multi-feed without damaging the barbs. These embodiments may have straight side walls and back spans that enable the surgical fasteners to remain properly aligned within a laparoscopic tube.

In one embodiment, surgical fasteners may incorporate active agents such anti-microbials and anti-adhesion materials. In one embodiment, surgical fasteners may incorporate radio-opacity to enable the surgical fasteners to be visible on x-ray imaging machines.

In one embodiment, ribs are formed on the outside of each leg of the surgical fastener, and an insertion fork has a mating channel that straddles each of the ribs. The ends of each fork tine bottom out in recesses or seating surfaces formed in the insertion tips of the surgical fastener. This above design transfers the complexity of manufacturing recesses from the legs of the surgical fastener to the tines of the insertion tool. This feature is especially important because the applicator instrument will preferably dispense multiple surgical fasteners (as opposed to just one insertion fork).

In one embodiment, an insertion tool includes a bridge that extends between proximal ends of fork tines. The shape of the bridge on the insertion tool may substantially conform to the proximal face of the bridge at the proximal end of the surgical fastener. In one embodiment, the insertion fork is designed so that the bridge element of the insertion fork comes into contact with the proximal end of the surgical fasteners at the time, or just prior to when, the distal ends of each fork bottoms out or engages the seating surfaces formed in the insertion tips of the surgical fastener. In one embodiment, the bridge of the insertion fork may include a softer (with respect to the durometer of the rest of the insertion fork) elastomeric material to reduce the required dimensional precision necessary to assure contact of the bridge and distal fork ends with the surgical fastener at about the same time. This configuration preferably enables the driving force behind the surgical fastener to be distributed along a greater surface area of the surgical fastener so as to reduce the pressure generated between the insertion tool and the surgical fastener.

These and other preferred embodiments of the invention will be described in more detail below.

