Abstract:
Described here are devices and methods for suture management. In some variations, the devices comprise an elongate tubular member having a proximal end, a distal end, a lumen therebetween, a cantilever blade positioned near the distal end of the elongate tubular member, and an expandable member positioned adjacent the cantilever blade for actuating the cantilever blade. Also described are devices comprising an elongate tubular member having a proximal end, a distal end, a lumen at least partially therebetween, and an aperture in a wall thereof for passage of a suture therethrough. These devices further comprise a blade connected to a blade housing disposed within the lumen, where the blade is oriented parallel to the longitudinal axis of the lumen. The blade and blade housing may be slidable within the lumen, or an inner shaft for may be slidable within the lumen. Methods of using the devices are also described.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Patent Application Ser. No. 60/974,051 filed on Sep. 20, 2007, which is hereby incorporated by reference in its entirety. 
    
    
     FIELD 
     In general, the devices and methods described herein relate to the manipulation and management of sutures or suture-like materials. In particular, the devices and methods described herein relate to remotely manipulating and managing sutures or suture-like materials. 
     BACKGROUND 
     The use of sutures has been widespread in surgical procedures. Sutures may be used to close incisions or wounds, to join tissue segments, or ligate sections of tissue. After a suture has been put to its intended use, it is often tied into a knot to secure it in place. When the suture is placed in a region having restricted access, tying a knot may be particularly difficult. Thus, knots are often formed outside of a patient and pushed toward the region. Once the knot has been positioned in the region, the ends of the suture generally need to be trimmed back, which may be difficult using standard instruments. As such, additional devices and methods for remotely manipulating a suture or suture-like material may be desirable. 
     BRIEF SUMMARY 
     Described here are devices and methods for suture management. In some variations, the devices comprise an elongate tubular member having a proximal end, a distal end, a lumen therebetween, a cantilever blade positioned near the distal end of the elongate tubular member, and an expandable member positioned adjacent the cantilever blade for actuating the cantilever blade. The lumen is configured for the passage of a suture at least partially therethrough. The expandable member may be any suitable expandable member. In some variations, the expandable member is inflatable (e.g., a balloon). In other variations, the expandable member comprises a pair of jaws. In still other variations, the device may include one or more retractable guides that may help to bring the suture into a position where it may be severed by the cantilever blade. In some variations, the retractable guide may comprise a guide loop. In other variations, the retractable guide may comprise a spiral loop. 
     Other devices for severing a suture are also described. For example, devices are also described comprising an elongate tubular member having a proximal end, a distal end, and a lumen therebetween, opposed cutting blades near the distal end, and an actuator for actuating the opposed cutting blades, where the actuator is disposed at least in part about the outer surface of the cutting blades. The actuator may be any suitable structure. In some variations, the actuator comprises an expandable member. In some of these variations, the actuator may be inflatable. In some of these variations, the actuator may be a balloon. In other variations, the actuator comprises actuation jaws configured to actuate the opposed blades when pulled proximally or pushed distally. In still other variations, the device may comprise a retractable guide as described above. 
     Additional devices are also described. For example, devices are described comprising an elongate tubular member having a proximal end, a distal end, and a lumen at least partially therebetween, the elongate tubular member comprising an aperture in a wall thereof for passage of a suture therethrough, and a blade connected to a blade housing and disposed within the lumen, where the blade is oriented parallel to the longitudinal axis of the lumen, and the blade and blade housing are slidable within the lumen. In some of these variations, the device further comprises an actuator configured to actuate the slidable blade. In some of these variations, the actuator may be an expandable member. In other variations, the actuator may be a pull wire. In still other variations, the actuator may include one or more magnets. In other variations, the actuator may include a plunger. Some variations of the devices described here further comprise a handle. In some of these variations, the handle comprises one or more safety features. The devices may include one or more retractable guides as described above. 
     Other described devices comprise a first elongate tubular member comprising a proximal end, a distal end, and a lumen at least partially therebetween, the first elongate tubular member having a substantially closed distal end having an aperture therein, the aperture having at least one cutting edge, and a second elongate tubular member comprising a proximal end, a distal end, and a lumen at least partially therebetween, the second elongate tubular member having a substantially closed distal end having an aperture therein, the aperture having at least one cutting edge. The first and second elongate tubular members are rotatable relative to one another such that upon rotation, the cutting edge of the first elongate tubular member and the cutting edge of the second elongate tubular member are brought toward one another. In some variations, the device comprises one or more retractable guides as described above. 
     Also described here are methods for severing a suture. In some variations, the methods comprise advancing a cutting assembly over a suture, the cutting assembly comprising a first elongate tubular member comprising a proximal end, a distal end, and a lumen at least partially therebetween, the first elongate tubular member having a substantially closed distal end having an aperture therein, the aperture having at least one cutting edge and a second elongate tubular member comprising a proximal end, a distal end, and a lumen at least partially therebetween, the second elongate tubular member having a substantially closed distal end, having an aperture therein, the aperture having at least one cutting edge, the suture passing through the distal end of the cutting assembly when the apertures of the first and second elongate tubular members are aligned, and rotating the first elongate tubular member with respect to the second elongate tubular member. Rotation of the first elongate tubular member with respect to the second elongate tubular member causes the cutting edges of the first and second elongate tubular members to be brought toward one another. 
     In other variations, the methods comprise retracting a blade assembly within an elongate tubular member to contact and sever a suture, the elongate tubular member comprising a proximal end, a distal end, and a lumen at least partially therethrough, the blade assembly comprising a blade and a blade housing, the blade assembly being slidably disposed within the lumen of the elongate tubular member, and wherein the blade is oriented parallel to the longitudinal axis of the lumen. In some of these variations, retracting the blade assembly comprises retracting the blade assembly using one or more magnets. In other variations, retracting the blade assembly comprises retracting the blade assembly using a shaft slidably disposed within the tubular member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a perspective view of one variation of a suture management device.  FIG. 1B  is a cross-sectional side view of the same suture management device. 
         FIG. 2  is a perspective view of a variation of a suture management device. 
         FIG. 3  is a cross-sectional side view of a suture management device having a cutting assembly with cutting jaws. 
         FIG. 4  is a cross-sectional side view of a suture management device having a cutting assembly with cutting jaws. 
         FIG. 5  is a cross-sectional side view of a suture management device having a cutting assembly with a cantilevered blade. 
         FIG. 6  is a cross-sectional side view of a suture management device having a cutting assembly with a longitudinally oriented blade. 
         FIGS. 7A and 7B  are cross-sectional side views of a suture management device having a balloon-actuated cutting assembly. 
         FIGS. 8A and 8B  are cross-sectional side views of a suture management device having a magnetically actuated cutting assembly. 
         FIGS. 9A  is a cross-sectional side view of a suture management device having a cutting assembly with cutting apertures.  FIGS. 9B-9D  are perspective views of the suture management device of  FIG. 9A . 
         FIGS. 10A and 10B  are side views of variations of handpieces having actuator handles. 
         FIGS. 11A-11C  are perspective views of a variation of a handpiece having a button and a safety lock.  FIG. 11D  is a cross-sectional side view of the handpiece of  FIGS. 11A-11C . 
         FIG. 12A  is a perspective view and  FIG. 12B  is a cross-sectional side view of a variation of a suture engagement portion. 
         FIGS. 13A and 13B  are perspective views of a suture engagement portion having a slot. 
         FIGS. 14A and 14B  are cross-sectional side views of a suture management device that may sever a suture knot. 
         FIGS. 15A-15C  are cross-sectional side views of a suture management device having a retractable guide with a guide loop. 
         FIG. 16  is a cross-sectional side view of a suture management device having a rectrable guide with a spiral loop. 
     
    
    
     DETAILED DESCRIPTION 
     Described here are devices and methods for managing and manipulating sutures remotely from a user. When reference is made to the term “suture” herein, it should be understood that the term suture is generic and is intended to capture a wide variety of sutures and suture-like materials, including materials such as filaments, yams, threads, chords, strips, and any combination of the foregoing, and the like. In some variations, the devices described here may be used to push or guide a suture, with or without a surgical knot, to a remote location. In some of these variations, the devices may be used to sever a suture at a location remote from the user. In some of these variations, the devices may be used to sever a suture at a predetermined or measured distance from a knot. Additionally, in some variations, the devices may be additionally configured to remove a knot or a knotted section of a tied suture. This may provide particular utility in instances where removing an undesirable suturing outcome is desirable. 
     Generally, the devices described here comprise a handpiece, a catheter body, and one or more cutting assemblies.  FIGS. 1A and 1B  show one such variation of suture management device ( 100 ).  FIG. 1A  shows a perspective view of suture management device ( 100 ), including handpiece ( 102 ) and catheter body ( 104 ). Also shown there is suture ( 106 ).  FIG. 1B  shows a cross-sectional side view of suture management device ( 100 ), further showing cutting assembly ( 108 ) including cutter jaws ( 110 ) held within catheter body ( 104 ). While shown in  FIG. 1B  as having cutter jaws ( 110 ), cutting assembly ( 108 ) may have any configuration of elements, as will be described in more detail below. In some variations, the device may further comprise a suture engagement portion.  FIG. 2  shows one such variation of suture management device ( 200 ). Shown there is handpiece ( 202 ), catheter section ( 204 ), and suture engagement portion ( 206 ). Suture engagement portion ( 206 ), which will be described in more detail below, generally engages at least a section of a suture (not shown) and may take on any suitable configuration. In other variations, the device may further comprise a retractable guide, which will be described in more detail below. 
     Catheter Section 
     In some variations, the suture management device comprises one or more catheter sections. A catheter section may be any structure capable of being advanced to a location remote from a user. For example, the catheter section may comprise a tube, sheath, or catheter body, which defines one or more lumens or channels. The catheter section may be made of any suitable material, may have any suitable geometry or configuration, and be made to have any suitable property. All or a portion of the catheter section may be flexible. Conversely, all or a portion of the catheter section may be rigid. Of course, the catheter section may be flexible along a portion of its length, and rigid along a portion of its length. 
     The catheter section may be guidable or steerable to a location remote from a user (e.g., using one or more pull or push wires, cables, or the like). Similarly, the catheter section may comprise or otherwise include one or more preshaped curves or bends along its length for facilitating positioning. The catheter section may also comprise one or more layers, coatings, or specialized surfaces. In some of these variations, at least a portion of the outer surface of the catheter section may be coated with, made from, or otherwise comprise a lubricious material such as PTFE. In others of these variations, the catheter section may comprise one or more coatings, reservoirs, or the like, which are configured to release one or more beneficial agents, such as, but not limited to antibiotics, antimicrobial agents, and anti-inflammatory agents. 
     Cutting Assemblies 
     The cutting assemblies described here may be used to sever a suture upon actuation of the suture management device. The cutting assembly may be contained entirely within a catheter section or a suture engagement portion, but need not be. In variations where the cutting assembly is entirely contained within the suture management device, the cutting assembly may be configured to come into contact only with suture. This, in turn, may prevent the cutting assembly from cutting or damaging bodily tissues. Additionally, the forces associated with operating the cutting assembly may be internalized within the suture management device, which may in turn prevent the cutting assembly from imparting a force to the suture management device. This may further prevent tissue trauma. 
     In some variations, the cutting assembly includes one or more cutter jaws. Indeed,  FIG. 3  illustrates a cross-sectional view of the distal end of one such variation of suture management device ( 300 ). Shown there is cutting assembly ( 302 ) enclosed within catheter section ( 304 ). In this variation, cutting assembly ( 302 ) comprises suture channel ( 306 ), actuation cannula ( 308 ) attached to actuation jaws ( 310 ), and cutter jaws ( 312 ) attached to catheter section ( 304 ) via connection sleeve ( 314 ). Also shown there is suture ( 316 ). While shown in  FIG. 3  as being disposed within catheter section ( 304 ), it should be appreciated that cutting assembly ( 302 ) may be located anywhere in or on suture management device ( 300 ), including, but not limited to, a handpiece (not shown) or a suture engagement portion (not shown). In the variation shown in  FIG. 3 , actuation cannula ( 308 ) and actuation jaws ( 310 ) may be slidably disposed within catheter section ( 304 ), and may be engagable with a handpiece (not shown) such that activation of the handpiece may withdraw actuation cannula ( 308 ) and actuation jaws ( 310 ) proximally relative to the rest of suture management device ( 300 ). As actuation jaws ( 310 ) are withdrawn proximally, they may engage cutterjaws ( 312 ). This engagement may cause cutter jaws ( 312 ), which may not slide relative to catheter section ( 304 ), to move toward the center of catheter section ( 304 ). As the cutterjaws ( 312 ) move toward each other, they may sever suture ( 316 ). The point at which cutter jaws ( 312 ) sever suture ( 316 ) may control the length of suture that remains beyond a surgical knot, for example, and it should be appreciated that the configuration of suture management device ( 300 ) may be altered to achieve a desirable cutting length. 
     While shown in  FIG. 3  as being fixed relative to catheter section ( 304 ), cutter jaws ( 312 ) may be engagable with a handpiece (not shown) to slide relative catheter section ( 304 ). In these variations, the actuation cannula ( 308 ) may be fixed to catheter section ( 304 ), and may decrease in diameter from the distal end of actuation cannula ( 308 ) to the proximal end of actuation cannula ( 308 ). When the handpiece is used to withdraw cutter jaws ( 312 ) proximally relative to suture management device ( 300 ), the cutter jaws ( 312 ) may engage actuation cannula ( 308 ). This may bring cutter jaws ( 312 ) together, and thereby cut suture ( 316 ). 
     While the variation of suture management device ( 300 ) shown in  FIG. 3  utilizes an actuator cannula that is withdrawn proximally relative to the catheter section, the actuator cannula may alternatively be configured to be pushed distally relative to the catheter section. Indeed,  FIG. 4  shows a cross-sectional side view of one such variation of suture management device ( 400 ), including catheter section ( 402 ). Shown there are cutter jaws ( 404 ) attached to actuation cannula ( 406 ), suture channel ( 408 ), and actuator jaws ( 410 ) fixed to catheter section ( 402 ). Also shown there is suture ( 412 ). Again, actuation cannula ( 406 ) may be able to slide relative to catheter section ( 402 ). In some variations, actuation cannula ( 406 ) may engage a handpiece (not shown) such that activation of the handpiece causes the actuation cannula ( 406 ) to slide distally relative to catheter section ( 402 ). As actuation cannula ( 406 ) slides distally, the cannula may engage actuator jaws ( 410 ). This engagement may cause cutter jaws ( 404 ) to move toward each other, which may in turn sever suture ( 412 ). 
     While shown in  FIGS. 3-4  as having two cutting jaws, the cutting assembly may have any number of cutting jaws. Indeed, the cutting assembly may have one, two, three, or four or more cutting jaws. In some variations, as will be described in more detail below, the cutting assembly includes alternative methods of cutting and does not include any cutting jaws. Indeed, while shown in  FIGS. 3-4  as having cutting jaws, the cutting assemblies described here may have any suitable cutting structure. For example, the cutting assembly may include one more cantilevered cutting blade.  FIG. 5  shows a cross-sectional side view of distal portion of one such variation of suture management device ( 500 ). Shown there is suture engagement portion ( 502 ) including suture channel ( 504 ), cantilever cutting blade ( 506 ) having blade edge ( 508 ), and balloon ( 510 ) having balloon lumen ( 512 ). Generally, cantilever cutting blade ( 506 ) may move between a standby position (not shown) to a cutting position where the blade edge ( 508 ) passes at least partially through suture channel ( 504 ). 
     To sever a suture (not shown) disposed within suture channel ( 504 ), balloon ( 510 ) may be inflated. The increase in volume of balloon ( 510 ) may bias cantilever cutting blade ( 506 ) away from the outer wall ( 514 ) of suture engagement portion ( 502 ), thereby moving cantilever cutting blade ( 506 ) to its cutting position, as shown in  FIG. 5 . Balloon ( 510 ) may be inflated by passing a fluid through balloon lumen ( 512 ) into balloon ( 510 ). This fluid may be any suitable gas or liquid. In some variations, cantilever cutting blade ( 506 ) may naturally return to its standby position when the balloon is deflated. In other variations, balloon ( 510 ) is attached to both cantilever cutting blade ( 506 ) and outer wall ( 514 ) of suture engagement portion ( 502 ), such that deflation of balloon ( 510 ) returns cantilever cutting blade ( 506 ) to its standby configuration. In still other variations, suture management device ( 500 ) may include some structure to return cantilever cutting blade ( 506 ) to its standby position when balloon ( 510 ) is deflated. In some of these variations, suture management device ( 500 ) comprises one or more springs that bias cantilever cutting blade ( 506 ) away from the cutting position. In others of these variations, suture management device ( 500 ) comprises one or more magnets that bias cantilever cutting blade ( 506 ) away from the cutting position. 
     While shown in  FIGS. 3-5  as having cutting blades or jaws with cutting surfaces that are oriented approximately perpendicular to the longitudinal axis of the suture management device, the cutting assemblies may have cutting blades or jaws that are oriented at any angle relative to the suture management device.  FIG. 6  illustrates a cross-sectional side view of one such variation of suture management device ( 600 ), including suture engagement portion ( 602 ) attached to catheter section ( 604 ). Shown there is blade housing ( 608 ) attached to longitudinally oriented blade ( 606 ) and inner shaft ( 610 ). Also shown there is suture ( 612 ) disposed at least partially within suture engagement portion ( 602 ). In variations such as these, blade housing ( 608 ) may be able to slide within suture engagement portion ( 602 ). Similarly, inner shaft ( 610 ) and plunger ( 614 ) may be able to slide within suture engagement portion ( 602 ) and catheter section ( 604 ). Additionally, inner shaft ( 610 ) may be engagable with blade housing ( 608 ) and a handpiece (not shown), such that activation of the handpiece causes inner shaft ( 610 ) to move distally relative to the suture management device ( 600 ). This in turn may move the inner shaft ( 610 ), plunger ( 614 ), and suture ( 612 ) distally relative to the suture management device ( 600 ), and may cause blade ( 606 ) to sever suture ( 612 ). Additionally, activation of the handpiece may be used to cause blade housing ( 608 ) to move proximally relative to suture management device ( 600 ). This in turn may move blade ( 606 ) proximally relative to suture management device ( 600 ), and may cause blade ( 606 ) to sever suture ( 612 ). While shown in  FIG. 6  as configured to push inner shaft ( 610 ), plunger ( 614 ), and suture ( 612 ) distally relative to suture management device ( 600 ) to sever a suture ( 612 ), suture management device ( 600 ) may alternatively be configured to pull blade ( 606 ) proximally to sever a suture. 
       FIGS. 7A and 7B  show another variation of suture management device ( 700 ) having cutting assembly ( 702 ) with a longitudinally oriented blade ( 704 ). Shown there is suture engagement portion ( 706 ) defining a suture channel ( 708 ), blade housing ( 710 ) attached to blade ( 704 ) and spring ( 714 ), balloon ( 716 ) having a balloon lumen ( 718 ), and catheter section ( 720 ). Blade housing ( 710 ) may be capable of sliding within catheter section ( 720 ). When balloon ( 716 ) is deflated, blade housing ( 710 ) may sit in a standby position, as shown in a cross-sectional side view in  FIG. 7A . In order to activate suture management device ( 700 ), balloon ( 716 ) may be inflated by passing a fluid, either liquid or gas, through balloon lumen ( 718 ). The inflated balloon ( 716 ) may push blade housing ( 710 ) distally relative to catheter section ( 720 ). This may in turn move blade ( 704 ) distally through blade channel ( 722 ) in suture engagement portion ( 706 ), as shown in  FIG. 7B . As blade ( 704 ) moves through blade channel ( 722 ), it may also move through suture channel ( 708 ) and may thereby sever a suture (not shown). Once balloon ( 716 ) is deflated, spring ( 714 ) may act to return blade housing ( 710 ) to its standby position. Similarly, suture management device ( 700 ) may alternatively or additionally include magnets or other structures that act to return blade housing ( 710 ) to its standby position. 
       FIGS. 8A and 8B  show still another variation of a suture management device ( 800 ) having cutting assembly ( 802 ) with a longitudinally oriented blade ( 804 ). Shown there is suture engagement portion ( 806 ) defining a suture channel ( 808 ), return magnet ( 810 ), blade housing ( 812 ) including housing magnet ( 814 ) and attached to blade ( 804 ), catheter section ( 816 ), and actuator rod ( 818 ) having actuator magnet ( 820 ). Blade housing ( 812 ) and actuator rod ( 818 ) may be able to slide within catheter section ( 816 ). Furthermore, the magnets may be axially magnetized and oriented such that housing magnet ( 814 ) is repelled by both return magnet ( 810 ) and actuator magnet ( 820 ). Additionally, the magnets may be configured such that the repulsive force between the housing magnet ( 814 ) and the actuator magnet ( 820 ) is stronger than the repulsive force between housing magnet ( 814 ) and return magnet ( 810 ). When cutting assembly ( 802 ) is not being activated, blade housing ( 812 ) may be in a standby position, as shown in a cross-sectional side view in  FIG. 8A . Actuator rod ( 818 ) may be engagable with a handpiece (not shown), such that activation of the handpiece causes actuator rod ( 818 ) to slide distally relative to catheter section ( 816 ). As actuator rod ( 818 ) moves distally, the repulsive force between actuator magnet ( 818 ) and housing magnet ( 814 ) may cause blade housing ( 812 ) to slide distally relative to catheter section ( 816 ), and may overcome the repulsive force between housing magnet ( 814 ) and return magnet ( 810 ). This may in turn cause blade ( 804 ) to move distally within blade channel ( 822 ), as shown in  FIG. 8B . This movement may result in blade ( 804 ) severing a suture (not shown). When the handpiece is no longer activated, and actuator rod ( 818 ) returns to its original position, the repulsive force between housing magnet ( 814 ) and return magnet ( 810 ) may cause blade housing ( 812 ) to return to its standby position. Alternatively or additionally, a return spring or other structure may act to return blade housing ( 812 ) to its standby position. 
       FIGS. 9A-9D  show another variation of suture management device ( 900 ) having cutting assembly ( 902 ).  FIGS. 9A and 9B  shows a cross-sectional side view and a cross-sectional perspective view, respectively, of suture management device ( 900 ) including inner cannula ( 904 ) and outer cannula ( 906 ). Also shown there is suture ( 908 ). Inner cannula ( 904 ) may be disposed within outer cannula ( 906 ), and may be capable of rotating relative to outer cannula ( 906 ). Additionally, inner cannula ( 904 ) may define an inner aperture ( 910 ), which may in turn have cutting edges ( 912 ), as shown in a perspective view in  FIG. 9C . Similarly, outer cannula ( 904 ) may define an outer aperture ( 914 ), which may also have cutting edges ( 912 ), as shown in a perspective view in  FIG. 9D . 
     Inner cannula ( 904 ) and outer cannula ( 906 ) may be aligned such that at least a portion of inner aperture ( 910 ) aligns with at least a portion of outer aperture ( 914 ), enabling suture ( 908 ) to pass through the inner ( 910 ) and outer ( 914 ) apertures. When inner cannula ( 904 ) is rotated relative to outer cannula ( 906 ), the cutting edges ( 912 ) of the inner ( 910 ) and outer ( 914 ) apertures are brought together, thereby decreasing the amount of overlap between inner ( 910 ) and outer ( 914 ) apertures, which may in turn sever suture ( 908 ). 
     While shown in  FIGS. 9A-9D  as having quarter-circle shapes, inner ( 910 ) and outer ( 914 ) apertures may have any size and shape. Indeed, inner ( 910 ) and outer ( 914 ) apertures may have a shape that approximates a circle, a half-circle, a triangle, a rectangle, an oval, a polygon, sections thereof or the like. Additionally, while shown in  FIGS. 9A-9D  as having the same size and shape, inner ( 910 ) and outer ( 914 ) apertures need not have the same size and shape. Indeed, inner ( 910 ) and outer ( 914 ) apertures may have the same shape but different sizes, may have different shapes but the same size, or may have different shapes and different sizes. 
     It should be appreciated that each cutting assembly may include any feature or combination of features as described above. Indeed, the cutting assemblies may include any number of cutting jaws, blades, apertures with cutting edges, combinations thereof and the like, and may be activated using magnets, balloons, actuator cannulas, rotating cannulas, combinations thereof or the like. 
     Handpieces 
     The handpieces described here may have any suitable configuration of elements. Generally, the handpiece may allow a user to guide or manipulate the suture management device within a body or enclosed space. The handpiece may further allow a user to guide or manipulate a suture at a location remote from the user. Additionally, the handpiece may control the actuation of one or more cutting assemblies, which may be used to sever a suture or a suture knot. 
     In some variations, the handpiece may comprise one or more actuation handles.  FIG. 10A  shows one such variation of handpiece ( 1000 ) comprising actuation handle ( 1002 ) and connected to catheter section ( 1004 ). Also shown there is connection sleeve ( 1006 ), actuation cannula ( 1008 ). Connection sleeve ( 1006 ) may connect actuation handle ( 1002 ) to actuation cannula ( 1008 ), which may in turn cause actuation cannula ( 1008 ) to move when actuation handle ( 1002 ) is squeezed. Actuation handle ( 1002 ) may provide a structure that is easily graspable by a user. Additionally, actuation handle ( 1002 ) may be used to control the severing of a suture (not shown), by activating a cutting assembly (not shown). 
     In some variations, such as that shown in  FIG. 10A , the actuation handle ( 1002 ) is configured to pull an actuation cannula ( 1006 ) proximally relative to catheter section ( 1008 ) when the actuation handle ( 1002 ) is compressed.  FIG. 10B  shows another variation of handpiece ( 1012 ) comprising actuation handle ( 1014 ) and connected to catheter section ( 1016 ). In these variations, actuation handle ( 1014 ) is configured to push actuation cannula ( 1018 ) distally relative to catheter section ( 1016 ) when actuation handle ( 1014 ) is compressed. In still other variations, the actuation handle may be configured to rotate a cannula when the actuation handle is compressed. 
     Additionally, in some variations the handpiece may comprise one or more safety features or locks that may prevent a user from accidentally activating a cutting assembly.  FIGS. 11A-11D  illustrate a variation of suture management device ( 1100 ) comprising handpiece ( 1102 ) connected to catheter section ( 1104 ).  FIG. 11A  shows a perspective view of suture management device ( 1100 ), comprising handle portion ( 1106 ), button ( 1108 ), and safety lock ( 1110 ). In these variations, button ( 1108 ) may be depressed relative to handle portion ( 1106 ) to activate a cutting assembly (not shown), as shown in  FIG. 11B . When safety lock ( 1108 ) engages handpiece ( 1102 ) as shown in  FIG. 11A , however, button ( 1108 ) may not be depressed. In order to depress button ( 1108 ), safety lock ( 1110 ) must first be removed, as shown in  FIG. 11C . Once the cutting assembly has been activated, a spring ( 1112 ) disposed within handpiece ( 1102 ) may return the button to its original position, as shown in a cross-sectional side view in  FIG. 11D , and the safety lock ( 1110 ) may be returned to the device. 
     While shown in  FIGS. 10-11B  as having actuation handles or buttons, the handpiece may comprise any suitable structure that is capable of activating a cutting assembly. These structures include, but are not limited to triggers, sliding actuators, cranks, knobs, rotating handles, combinations thereof, and the like. Additionally, in variations where the suture management device comprises a retractable guide, as will be described in more detail below, the handpiece may additionally include one or more structures to retract retractable guide into the catheter section. The handle may also comprise a luer for attachment to one or more inflation lumens in the case of balloon actuating cutting mechanisms. 
     Suture Channels and Suture Engagement Portions 
     Generally, the suture management devices described here may comprise one or more suture channels through which one or more sutures may be passed. The suture channel may have ends positioned at any two suitable locations on the suture management device. The placement of the suture channel may be determined by the configuration of a cutting assembly or another feature of the device. In some variations, the suture passes through a suture channel that spans between the proximal and distal ends of the suture management device, as shown in  FIGS. 1A and 1B . In other variations, the suture channel enters and exits the suture management device through a suture engagement portion or other aperture. 
       FIGS. 12A and 12B  illustrate one variation of suture engagement portion ( 1200 ).  FIG. 12A  shows a perspective view and  FIG. 12B  shows a cross-sectional side view of suture engagement portion ( 1200 ). Shown there is suture channel ( 1202 ), cantilever cutting blade ( 1204 ) having blade edge ( 1206 ), and balloon ( 1208 ) having balloon lumen ( 1210 ). In this variation, suture channel has a suture entrance ( 1212 ) at the distal end of suture engagement portion ( 1200 ) and a suture exit ( 1214 ) in wall ( 1216 ) of suture engagement portion ( 1200 ). A suture (not shown) may be passed from suture entrance ( 1212 ) to suture exit ( 1214 ), or vice versa, thereby allowing suture engagement portion ( 1200 ) to engage a portion of a suture. 
       FIGS. 12A and 12B  show suture engagement portion ( 1200 ) as having a structure that may be independent of a catheter section (not shown), but it need not. In some variations, the suture engagement portion may be integral with a catheter section. Additionally, the suture engagement portion may be located at any point along the device. In some variations, the suture engagement portion may be located at the distal end of the suture management device. In other variations, the suture engagement portion may be located at some point along the length of a catheter section. 
     In some variations that include a suture engagement portion, the suture engagement portion may include one or more slots on the surface of suture engagement portion. These slots may allow the suture engagement portion to engage a portion of a suture without the need to pass one end of the suture through the suture channel. These variations may find particular utility in instances when no end of a suture is available, or a tangled section of suture would otherwise prevent engagement between the suture management device and a portion of the suture.  FIGS. 13A and 13B  show perspective views one such variation of suture engagement portion ( 1300 ). Shown there is suture engagement portion ( 1300 ) attached to catheter section ( 1304 ) and comprising slot ( 1306 ). Also shown there is suture ( 1308 ). Slot ( 1306 ) may comprise transverse segment ( 1310 ), longitudinal segments ( 1312 ), and suture tab ( 1314 ). 
     In order to engage suture engagement portion ( 1300 ), suture ( 1308 ) may be placed within transverse segment ( 1310 ), as shown in  FIG. 13A . The suture ( 1308 ) may then be threaded through longitudinal segments ( 1312 ) and past suture tab ( 1314 ), such that suture ( 1308 ) enters the side of suture engagement portion ( 1300 ) and exits at the distal end of suture engagement portion ( 1300 ). Suture tab ( 1314 ) may serve to prevent suture ( 1308 ) from disengaging with suture engagement portion ( 1300 ) while the suture management device is manipulated or advanced. 
     While shown in  FIGS. 13A and 13B  as having both transverse ( 1310 ) and longitudinal ( 1312 ) segments, slot ( 1306 ) may have any suitable configuration. Indeed, slot ( 1306 ) may have any combination of linear or arced sections, and these sections may be oriented within suture engagement portion ( 1300 ) in any suitable configuration. Additionally, while shown in  FIGS. 13A and 13B  as sized to accept one suture ( 1308 ), slot ( 1306 ) may be sized to accept two, three or four or more sutures ( 1308 ). Furthermore, suture engagement portion ( 1300 ) may have any number of slots ( 1306 ), and each slot ( 1306 ) may have any number of suture tabs ( 1314 ). Generally, suture tab ( 1314 ) may be any structure that resists movement of a suture through slot ( 1306 ). 
     In variations in which the suture management device comprises one or more suture channels, these suture channels may have any suitable shape or configuration. In some variations, the suture channel may be configured such that bodily tissue is incapable of entering the suture channel. This may provide an additional level of safety as it may prevent tissue from contacting the cutting assembly. In some variations, the suture channel may be configured to accept only one suture. In other variations, the suture channel may be configured to accept two, three, or four or more sutures. In still other variations, the suture channel may be sized such that a suture may pass therethrough while a knotted section of the suture may not pass therethrough. In these variations, the suture management device may be able to push a knotted section of suture to a location remote from a user. In yet other variations, the suture channel may be sized to accept a retractable guide, as described in more detail below, and one or more sutures. 
     In some variations, the suture management device includes one or more features that allow a user to remove a suture knot in the event of an undesirable suturing outcome.  FIGS. 14A and 14B  show one such variation of suture management device ( 1400 ), including suture engagement portion ( 1402 ). More specifically,  FIG. 14A  shows a cross-sectional side view of suture management device ( 1400 ). Also shown there is suture channel ( 1406 ) having first section ( 1408 ) and second section ( 1410 ), cantilever blade ( 1412 ), and balloon ( 1414 ) with balloon lumen ( 1416 ). Second section ( 1410 ) of suture channel may sized such that a both a suture ( 1418 ) and a suture knot ( 1420 ) may pass therethrough, as shown in  FIG. 14B . First section ( 1408 ) may be sized such that suture ( 1418 ) may pass therethrough, but suture knot ( 1420 ) may not. This may serve to position suture knot ( 1420 ) such that activation of cantilever blade ( 1412 ) will sever both suture ( 1418 ) and suture knot ( 1420 ). 
     Retractable Guide 
     In some variations, the devices described here comprise a retractable guide.  FIGS. 15A-15C  illustrate a variation of suture management device ( 1500 ).  FIG. 15A  shows a perspective view of the entire suture management device ( 1500 ). Shown there is handpiece ( 1502 ) with sliding actuator ( 1504 ) and push actuator ( 1506 ), and catheter section ( 1508 ) having suture channel ( 1510 ), retractable guide ( 1512 ) with guide loop ( 1514 ), marker ( 1516 ), and push rod ( 1518 ) with blade ( 1520 ). Retractable guide ( 1512 ) may be disposed within suture channel ( 1510 ), and may be withdrawn proximally into suture channel ( 1510 ) upon activation of sliding actuator ( 1504 ). Similarly, blade ( 1520 ) may be advanced distally relative to catheter section ( 1508 ) upon activation of push actuator ( 1506 ). 
     To use suture management device ( 1500 ), a suture ( 1522 ) may be threaded through guide loop ( 1514 ), and suture management device ( 1500 ) may be advanced over suture ( 1522 ) to a target site ( 1524 ), as shown in  FIG. 15B . In some variations, this advancement may be visualized using marker ( 1516 ) and/or imaging methods such as fluoroscopy or ultrasound to ensure suture management device ( 1500 ) is properly placed. Once suture management device ( 1500 ) has been properly placed, retractable guide ( 1512 ) may be withdrawn into suture channel ( 1510 ) using slide actuator ( 1504 ). This may in turn cause guide loop ( 1514 ) to engage suture ( 1522 ) and pull suture ( 1522 ) at least partially within suture channel ( 1510 ), as shown in  FIG. 15C . Once suture ( 1522 ) has been pulled into suture channel ( 1510 ), blade ( 1520 ) may be advanced to sever suture ( 1522 ). 
     While shown in  FIGS. 15A-15C  as having a marker ( 1516 ), suture management device ( 1500 ) need not. In variations that do include a marker ( 1516 ), the marker ( 1516 ) may be made of any material that is capable of being viewed by an imaging method (e.g., fluoroscopy, ultrasound, etc.). Although shown in  FIGS. 15A-15C  as being located on the distal end of catheter section ( 1508 ), marker may be disposed anywhere in, on, or along suture management device ( 1500 ). Additionally, while shown in  FIGS. 15A-15C  as having only one marker, suture management device ( 1500 ) may have any number of markers. Indeed, suture management device ( 1500 ) may have zero, one, or two or more markers. 
     Additionally, while shown in  FIGS. 15A-15C  as having a guide loop ( 1514 ), the retractable guide ( 1512 ) may have any suitable structure for engaging suture ( 1522 ). Indeed,  FIG. 16  shows another variation of suture management device ( 1600 ), having catheter section ( 1602 ) with cutting assembly ( 1604 ), suture channel ( 1606 ), and retractable guide ( 1608 ) having spiral loop ( 1610 ). Also shown there is suture ( 1612 ). Spiral loop ( 1610 ) may be wound around suture ( 1612 ) to engage suture, which may allow suture management device ( 1600 ) to engage suture ( 1612 ) without the need to thread one end of suture ( 1612 ) through the retractable guide ( 1608 ). This may provide particular utility in instances where neither end of the suture is available to be threaded through retractable guide ( 1608 ). Generally, the retractable guide may be any structure capable of being withdrawn into a suture channel, may be made of any suitable material, and may have any suitable geometry (e.g., one or more curves or bends). Examples of suitable materials include, but are not limited to nickel titanium alloys, stainless steel, PET, polyether block amide, and combinations thereof. 
     It should be appreciated that the devices described here may include any combination of elements of as described above. More specifically, the suture management devices may include any combination of handpieces, catheter sections, cutting assemblies, markers, and retractable guides as described above. 
     Methods 
     Any of the suture management devices described above may be used to sever a suture at a point remote from a user. In some methods, a suture is used in a procedure at a target location. This procedure may be any suitable procedure, including, but not limited to, wound closure, drawing together two tissue segments, and ligating an area of tissue such as the left atrial appendage. In some of these methods, a knot may then be tied at the target site. This knot may be any suitable knot, including but not limited to a slip knot. In some of these methods, a suture management device may engage at least a portion of the suture. 
     The suture management device may engage the suture in any suitable manner as described above, and this engagement may depend on the configuration of elements in the device. In variations where the suture management device includes a suture channel, a free end of the suture may be threaded through one end of the suture channel and passed through the other end. In variations in which the suture management device includes one or more slots, the suture may be threaded through suture channel via the one or more slots. In variations where the suture management device comprises a retractable guide, the retractable guide may engage the suture. For example, when the retractable guide comprises a guide loop, an end of the suture may be passed through the eye of the guide loop. Alternatively, in variations where the retractable guide includes a spiral loop, and the spiral loop may be wrapped around a portion of the suture, or an end of the suture may be passed through the spiral loop. 
     Once the suture management device has engaged the suture, the suture management device may be advanced along the suture to the target site. In some variations, the suture management device may be advanced to the target site simultaneously with engaging the suture. For example, in variations where the suture is threaded between the ends of a suture channel, the suture management device may be advanced toward the target site while the suture is being threaded. In some variations, the suture acts to guide the suture management device to the target location. Indeed, in variations that include a retractable guide, the engagement between the retractable guide and the suture may serve to lead the suture management along the length of the suture until it reaches the target site. Similarly, the suture management device may be advanced to the target site through one or more catheters or catheter assemblies, a sheath, or other introducer, which may or may not be engaged with the suture, and which may or may not include one or more curves or bends. In some of these methods, the suture management device may be advanced under fluoroscopic or ultrasonic guidance. 
     As the suture management device is advanced to the target site, a portion of the device may abut the knot. In some of these variations, the suture management device may hold the knot in place, yet still allow a portion of suture to move freely through the device. In some of these variations, a portion of suture may be withdrawn through the device relative to the knot. In some variations, this may serve to tighten the knot. In other variations, such as variations that include a slip knot, this may serve to cinch a loop of suture. 
     Once the desired knot tightness, and knot and suture placement has been achieved, the suture management device may then be activated to sever the suture. In some variations, activation of the suture management device results in the activation of a cutting assembly. It should be noted that any of the cutting assemblies as described above may be used to sever a suture. In variations that include a retractable guide, the retractable guide may first be withdrawn into the device, which may in turn pull a portion of the suture into the device, where it may be severed by the cutting assembly. In some variations, suture management devices may be used to remove a knot in the case of an undesirable suturing outcome. Additionally, the suture management device may be configured to sever a suture such that a predetermined amount of suture remains. In some variations, this may be achieved by configuring the cutting portion of the cutting assembly to sever a suture at a given distance from the distal end of the device. If the end of the suture management device is abutting the knot, a user may know how much suture will remain relative to the knot when the suture is severed. If a longer length of suture is desired, the cutting assembly may be reconfigured, or the user may withdraw the suture management device a certain amount relative to the suture (and thus the knot). 
     In some methods, a knot may be tied extracorporeally, and then advanced to the target site. In other methods, a suture management device may be used to advance the knot to the target site. In these methods, the suture management device may engage at least a portion of the suture as described above. Generally, a portion of the suture management device may abut or otherwise contact the knot such that as the suture management device is advanced, it pushes the knot. As such, the knot may be pushed to the target location by the suture management device. In some of these variations, a portion of the suture may act to guide the suture management device to the target site. Of course, as described above, the suture management device may also be advanced to the target site through one or more catheters or catheter assemblies, a sheath, or other introducer, which may or may not be engaged with the suture, and which may or may not include one or more curves or bends. In these or other variations, the suture management device may be advanced under fluoroscopic or ultrasonic guidance. Once the knot has been positioned at the target sit, it may be tightened or removed, as described above. Similarly, once the proper tightness has been achieved, the suture management device may sever the suture, as described above. 
     In still other methods, the suture management devices described here may be used to ligate a portion of tissue, such as the left atrial appendage. In these variations, one end of a suture may be tied to itself using a slip knot or similar knot to create a loop. A suture management device may engage the suture in any of the ways as described above, and the suture management device may be used to guide the loop to a target location. Again, the suture management device may be advanced to the target site through one or more catheters or catheter assemblies, sheaths, or other introducers. In some methods, this advancement may occur under fluoroscopic or ultrasonic visualization. Once at the target site, the loop may be placed around the tissue to be ligated. In some variations, the suture management device may be manipulated to place the loop around the target tissue. In other variations, one or more additional tools may be advanced to the target location to help place the loop around the target tissue. Once in place, one end of the suture may be withdrawn through the suture management device to cinch the tissue. The knot and suture may be removed in the case of an undesirable suturing outcome, otherwise the knot may be tightened and the suture severed as described above. 
     While devices and methods have been described in some detail here by way of illustration and example, such illustration and example may be for purposes of clarity of understanding only. It will be readily apparent to those of ordinary skill in the art in light of the teachings herein that certain changes and modifications may be made thereto without departing from the spirit and scope of the appended claims.