Abstract:
A needle knife sphincterotome comprising a tensioning filament for positionally adjusting its distal end and a needle knife configured for tissue aspiration. The sphincterotome includes an actuatable handle attached to an elongate shaft having a needle knife near its distal end. The tensioning filament includes proximal and distal attachments and is configured such that actuation of the handle introduces a tension in the tensioning filament that bends, arches, or otherwise deforms the distal end of the sphincterotome shaft.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims priority to U.S. Provisional Application Ser. No. 60/852,197, filed Oct. 17, 2006, which is incorporated herein by reference in its entirety. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present device relates to medical devices, and specifically to improvements to a wire-guided aspiration needle or needle knife.  
       BACKGROUND OF THE INVENTION  
       [0003]     In endoscopic, or other minimally invasive surgery, generically referred to herein as endoscopic surgery, a needle knife may be used in conjunction with an endoscope to provide surgical cutting inside a patient. For example, a needle knife may used during certain procedures to make an incision in a sphincter (sphincterotomy). As one example, a common treatment of cholecystitis includes the removal of gallstones from the common bile duct. This is frequently done endoscopically with the use of a duodenoscope. The common bile duct proceeds from the junction of the common hepatic duct with the cystic duct, which is open to the gall bladder, and merges with the pancreatic duct, forming the ampulla of Vater, which itself opens into the duodenum at the papilla of Vater. The sphincter of Oddi is a muscular ring that controls passage of fluid from the ampulla of Vater into the duodenum. For removal of gallstones in an endoscopic procedure, access to the common bile duct for removal of gallstones is eased using a needle knife sphincterotome (or side-wire sphincterotome) to incise or sever the sphincter of Oddi. The needle knife sphincterotome is introduced through the duodenoscope and guided through the duodenum to the common bile duct. Once the tool is guided into the sphincter, its cutting element is used to incise the sphincter, and thereby improve access to the bile duct and impacted gallstones. The needle knife cutting tip may be hollow and provide a path of fluid communication with a lumen from the distal cutting element through an elongate catheter forming the major length of its body to allow for aspiration of tissue therethrough.  
         [0004]     Another example of a common procedure utilizing a needle knife sphincterotome is endoscopic retrograde cholangiopancreatography (ERCP), a diagnostic visualization technique used for variety of clinical applications. In this procedure, a contrast fluid such as a radio-opaque dye is introduced through a tube into the ampulla of Vater. A needle knife sphincterotome is often employed to provide access through the sphincter of Oddi in the same manner as described above. ERCP is often used in diagnosis of cholecystitis, as well as in the diagnosis and treatment of other conditions of the pancreatic and common bile ducts and related structures.  
         [0005]     As illustrated in  FIG. 1 , one prior art needle knife sphincterotome  100  includes a handle  110  attached to a catheter shaft  102  generally made of PTFE (polytetrafluoroethylene) or another flexible material. The sphincterotome  100  includes a wire guide lumen  106  extending through the shaft  102  and open to a side port  104 , which allows the tome  100  to be directed over a wire guide  108  in either of a long-wire (not shown) or short-wire (“rapid exchange”) manner, a configuration known in the art as “convertible” or “dual use”. An electrode means  114  is included in the handle  110  for connection to an electrosurgical generator (not shown) for providing current to a distal needle knife  109 . Electric current passed from an electrode  114  in the handle  110  enables the knife  109  to act as an electrosurgical cutting element that may be used effectively to cut and cauterize tissue, such as the sphincter of Oddi in the exemplary procedures described above. The knife  109  may include a lumen (not shown) extending therethrough (and extending up through the shaft) to aspirate tissue.  
         [0006]     It would be advantageous to provide a distal steering means enabling a user to direct the distal end of a needle knife sphincterotome by manipulation of a proximal handle means independent of a wire guide.  
       BRIEF SUMMARY OF THE INVENTION  
       [0007]     In one aspect, the present invention includes a sphincterotome that includes a handle assembly, a flexible elongate shaft, and a tensioning filament. The flexible elongate shaft is connected to the handle assembly and includes a first lumen, a proximal end, and a distal end. An electroconductive component extends through at least a portion of the elongate shaft and includes a proximal component section and a distal component section. The proximal component section is attached to an electrode in the handle assembly, and the distal component section extends beyond the distal end of the elongate shaft to form a cutting element. The tensioning filament includes a proximal filament section and a distal filament section. The proximal filament section is slidably disposed at least partially in the first lumen and has a proximal attachment to the handle assembly. A portion of the distal filament section exits the first lumen and is attached near the distal end of the shaft. The attachment mounting of the filament is configured such that, when the handle assembly is actuated, the filament is moved longitudinally in a manner that deforms a distal portion of the shaft.  
         [0008]     In another aspect, the present invention includes a needle knife sphincterotome that includes a proximal handle assembly, an elongate shaft distally extendable from the handle assembly, an electroconductive needle knife element disposed in the elongate shaft and projecting generally distally therefrom, and a tensioning filament connecting the handle assembly to a region near a distal end of the elongate shaft and configured such that an actuation of the handle assembly exerts a deforming tension upon the distal end of the elongate shaft. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  is a typical prior art sphincterotome;  
         [0010]      FIG. 2  is an external side view of a sphincterotome embodiment of the present invention;  
         [0011]      FIG. 2A  is a cross-sectional view of the embodiment of  FIG. 2 , taken along line  2 A- 2 A;  
         [0012]      FIGS. 2B-2B  are side views of the embodiment of  FIG. 2 , showing—respectively—default/relaxed and actuated states of the device;  
         [0013]      FIG. 3  shows an external side view of another sphincterotome embodiment of the present invention in a non-actuated state;  
         [0014]      FIGS. 3A-3B  depict a handle-locking mechanism of the embodiment shown in  FIG. 3 ;  
         [0015]      FIG. 3C  illustrates the sphincterotome of  FIG. 3  in an actuated state; and  
         [0016]      FIG. 3D  shows a cross-section of a shaft portion of the sphincterotome of  FIG. 3  taken along line  3 D- 3 D. 
     
    
     DETAILED DESCRIPTION  
       [0017]     The following disclosure describes embodiments of a needle knife sphincterotome including a tensioning filament/wire that provides for steering the distal end of the sphincterotome independent of a wire guide. Those of skill in the art will appreciate that variations of the described embodiments as well as other embodiments are possible and are within the scope of this application.  
         [0018]      FIGS. 2-2A  illustrate one embodiment of a needle knife sphincterotome  200 .  FIG. 2  shows a side external view of the tome  200 , and  FIG. 2A  shows a cross-sectional view along the perspective of line  2 A- 2 A. The proximal end includes a handle assembly  210 , which has a first portion and a second portion. In the illustrated embodiment, the first portion is a one-ring (also referred to as a thumb ring or stem) handle component  212  that is attached to the proximal end of the catheter shaft  214  of the sphincterotome  200 . The second portion is a two-ring (also referred to as a finger ring or spool) handle component  216  that is slidably mounted to the one-ring handle component  212 . The two-ring handle component  216  is connected to a steering filament  250 . The two-ring handle component  216  includes a housing  218  supporting an electrode  220 . Also, the two-ring handle component includes a dual port structure  230 , which has a first port  232  open to a wire guide lumen  234  of the catheter and a second port  236  that provides access to a needle lumen  237  and, optionally, to an aspiration/irrigation lumen  238  that extends through an aspiration needle/needle knife  240 , which itself is slidably disposed through the needle lumen  237 . Those of skill in the art will appreciate that the lumen  238  may be configured and used for aspiration of tissue from the distal to the proximal portion of the needle  240 , and/or for introduction of a fluid therethrough (e.g., irrigation fluid, radio-contrast fluid). A body portion of the knife  240  extends proximally and is in electroconductive contact with the electrode  220 . In other embodiments, the needle  240  may be solid (i.e., lacking a lumen). Persons of skill in the art will appreciate that many other embodiments of a sphincterotome handle are possible and practicable within the scope of the present invention. For example, the handle assembly may use a different number of rings, a trigger grip, or other gripping surfaces adapted for manipulating a sphincterotome. As another example, the connection between handle components and the shaft and filament may be reversed. Other structures such as a utility port for fluid communication access to a lumen in the sphincterotome shaft may also be located on a first or second portion of a handle assembly.  
         [0019]     In the illustrated embodiment, the catheter shaft  214  includes a side port  242  near the distal end, which provides for use of the tome  200  along a wire guide in “rapid exchange configuration” by allowing a wire guide to pass out through the side port  242  without having to travel through the length of the shaft  214 . As shown, a wire guide  244  extends through the wire guide lumen  234  in a “long wire configuration.” During a procedure using the tome  200 , it is preferable that the wire guide  244  not extend beyond a distal cutting/coagulation end  240   a  of the knife  240 , which end  240   a  may be disposed in line with, parallel to, or at an angle to a central longitudinal axis of the shaft  214 . In the illustrated embodiment, the needle  240  includes a proximally-mounted guide-ring  241 , which allows the needle end  240   a  to be retracted into or extended from the needle lumen  237  of the shaft  214 . The guide-ring  241  includes an optional catch  241   a  for engaging the port  236  and holding the needle  240  in the extended position illustrated in  FIG. 2 . In other embodiments, the needle  240  may be fixed in an extended position.  
         [0020]     The tome  200  also includes the distal-steering filament  250 . The proximal end of the filament  250  is attached to the two-ring handle component  216 , and the filament  250  extends distally through a filament lumen  252  to and through a side aperture  254  near the distal catheter end, and is attached nearer the distal end of the catheter  214 . The filament  250  provides a user with the ability to steer the distal end of the tome catheter  214  by moving the handle components  212 ,  216  relative to each other. As shown in  FIG. 2B , which shows the handles and includes a detail, partially cut-away view of a distal end of the sphincterotome  200 , the distal end portion of the catheter  214  is generally aligned with its main longitudinal axis, which is the default position for the catheter  214  and handles.  FIG. 2C  illustrates the same perspective view as  FIG. 2B  and shows that, when the handle components  214 ,  216  are drawn together, the filament  250  is pulled proximally relative to the catheter  214 , which bends, curves, or otherwise deforms the distal catheter end as the filament  250  is drawn proximally through the side aperture  254  and its distal end pulls on the distal catheter end. During an operation of the tome  200 , this allows a user greater steering control of the distal catheter end and the knife end  240   a  mounted thereon, specifically allowing the user to move the axis of the knife end  240   a  out of alignment with the primary longitudinal axis of the catheter  214 . This feature may allow for steering around corners, as well as allowing the knife end  240   a  to be used on a surface that is parallel (or nearly so) with the primary longitudinal axis of the tome&#39;s catheter  214 . In an alternative embodiment, the filament  250  may be electroconductive and be in electroconductive communication with the electrode  220  such that the filament may be used as a cutting/coagulation wire in the same manner as side-wire sphincterotomes known in the art (e.g., Fusion® OMNI-Tome by Cook Endoscopy).  
         [0021]      FIGS. 3-3D  illustrate another embodiment of a needle knife sphincterotome  300  configured with a handle-locking mechanism, a needle actuation mechanism, and a means for distorting a distal portion of the tome  300 .  FIG. 3  shows a side external view of the tome  300  in a non-deployed state. The proximal end includes a handle assembly  310 , which has a first portion and a second portion. In the illustrated embodiment, the first portion is a one-ring (also referred to as a thumb ring or stem) handle component  312  that is attached to the proximal end of the catheter shaft  314  of the sphincterotome  300 . The second portion is a two-ring (also referred to as a finger ring or spool) handle component  316  that is slidably mounted to the one-ring handle component  312 . The two-ring handle component  316  is connected to a steering filament  350 . The two-ring handle component  316  includes a housing  318  supporting an electrode  320 .  
         [0022]     The handle assembly  310  has a locking mechanism that includes an off-center-mounted friction wheel  313  rotatably mounted to the two-ring handle component  316  and disposed such that its surface may frictionally engage the one-ring handle component  312  to limit the ability of, or prevent, the handle components  312 ,  316  from sliding relative to each other.  FIGS. 3A-3B  show a diagrammatic cross-section along line  3 A- 3 A. Specifically,  FIG. 3A  depicts the friction wheel  313  in an “unlocked orientation” wherein the two handle portions  312 ,  316  are freely slidable relative to each other. In contrast,  FIG. 3B  shows the friction wheel  313  in a “locked orientation” where it is rotated to frictionally engage a surface of the one-ring handle component  312 . The engagement shown is most effective at preventing movement of the handles  312 ,  316  apart from each other, and those of skill in the art will appreciate that other mechanisms for locking the handles relative to each other may be provided in accord with the present invention. For example, a transversely mounted thumb-screw, a detent mechanism, or some other locking means may be provided.  
         [0023]     Also, the two-ring handle component includes a distal dual port structure  330 , which has a first port  332  open to a wire guide lumen  334  of the catheter and a second port  336  that optionally provides access to a needle lumen  337  and/or to an aspiration/irrigation lumen  338  that extends through an aspiration needle/needle knife  340 , which itself is slidably disposed through the needle lumen  337 . In  FIG. 3 , the needle  340  is shown in a retracted position Those of skill in the art will appreciate that the lumen  338  may be configured and used for aspiration of tissue from the distal to the proximal portion of the needle  340 , and/or for introduction of a fluid therethrough (e.g., irrigation fluid, radio-contrast fluid). A body portion of the knife  340  extends proximally and is in electroconductive contact (not shown) with the electrode  320 . In other embodiments, the needle  340  may be generally solid (i.e., lacking a lumen). Persons of skill in the art will appreciate that many other embodiments of a sphincterotome handle are possible and practicable. For example, the handle assembly may use a different number of rings, a trigger grip, or other gripping surfaces adapted for manipulating a sphincterotome. As another example, the connection between handle components and the shaft and filament may be reversed. Other structures such as a utility port for fluid communication access to a lumen in the sphincterotome shaft may also be located on a first or second portion of a handle assembly.  
         [0024]     As shown in  FIGS. 3 and 3 C, the needle  340  includes a proximally-mounted guide-ring  341 , which allows the needle end  340   a  to be retracted into or extended from the needle lumen  337  of the shaft  314 . The guide-ring  341  is mounted to a housing  341   a,  which includes an optional catch  341   b  configured for holding the needle  340  in a retracted position as shown in  FIG. 3 , or in an extended position as illustrated in  FIG. 3C . The optional catch  341   b  is configured as a bayonet-type slide catch and includes a slot  341   c  in which travels a boss  341   d  protruding from the guide-ring  341 . As those of skill in the art will appreciate from the depictions in  FIGS. 3 and 3 C, the needle end  340   a  can be extended distally by actuation of the guide-ring  341 . Actuation of the guide-ring includes rotating the guide-ring  341  to guide its boss  341   d  out of an upper inverted-J-portion of the slot  341   c,  then moving the guide-ring  341  down/distally so that the boss  341   d  travels down the major length of the slot  341   c.  The actuation is concluded by rotating the guide-ring  341  to guide the boss  341   d  into engagement with a lower J-portion of the slot  341   c.    
         [0025]     In the illustrated embodiment, the catheter shaft  314  includes a side port  342  near the distal end, which provides for use of the tome  300  along a wire guide in “rapid exchange configuration” by allowing a wire guide to pass out through the side port  342  without having to travel through the length of the shaft  314 . During a procedure using the tome  300 , it is preferable that the wire guide (not shown) not extend beyond a distal cutting/coagulation end  340   a  of the knife  340 , which end  340   a  may be disposed in line with, parallel to, or at an angle to a central longitudinal axis of the shaft  314 .  
         [0026]     The tome  300  also includes the distal-steering filament  350 . The proximal end of the filament  350  is attached to the two-ring handle component  316 , and the filament  350  extends distally through a filament lumen  352  to and through a side aperture  354  near the distal catheter end, and is attached nearer the distal end of the catheter  314 . The filament  350  provides a user with the ability to steer the distal end of the tome catheter  314  by moving the handle components  312 ,  316  relative to each other.  FIG. 3C  illustrates the same view as  FIG. 3A  and—in addition to the extension of the needle end  340   a  described above—shows that, when the handle components  314 ,  316  are drawn together, the filament  350  is pulled proximally relative to the catheter  314 , which bends, curves, or otherwise deforms the distal catheter end as the filament is drawn proximally through the side aperture  354  and its distal end pulls on the distal catheter end. During an operation of the tome  300 , this allows a user greater steering control of the distal catheter end (independent of the wire guide, for example, if the wire guide has been partially retracted) and the knife end  340   a  mounted thereon, specifically allowing the user to move the axis of the knife end  340   a  out of alignment with the primary longitudinal axis of the catheter  314 . This feature may allow for the knife end  340   a  to be used on a surface that is parallel (or nearly so) with the primary longitudinal axis of the tome&#39;s catheter  314 . As shown in the illustrated embodiment, actuation of the needle end  340   a  and the filament  350  are independent of each other.  FIG. 3D  shows a cross-sectional view of the catheter portion  314  along line  3 D- 3 D.  
         [0027]     In preferred embodiments, one or more optically visible and/or radio-opaque markers (not shown) are placed at predetermined locations in or on the catheter to aid fluoroscopic imaging and navigation during procedures using a device of the present invention.  
         [0028]     Persons of skill in the art will appreciate that variants of the sphincterotome with a steering mechanism described herein are within the scope of the present invention. It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, that are intended to define the spirit and scope of this invention.