Steerable access sheath and methods of use

Abstract

The present invention provides devices, systems, methods and kits for endoscopically accessing a body cavity and providing a directed pathway toward a target tissue within the cavity. The directed pathway is provided by an access sheath which is positioned in a desired configuration, generally directed toward the target tissue. Depending on the location of the target tissue and the desired angle of approach, the access sheath may be required to maintain one or more curves in one or more planes to properly direct the interventional devices. In addition, the access sheath has a locking feature to hold the sheath in place and maintain the desired configuration. Interventional devices may then be passed through the sheath to the target tissue.

What is claimed is:  
     
         1 . An articulatable access system for accessing a body cavity comprising: 
 a shaft having a proximal end, a distal end, and a central lumen therethrough, wherein the distal end is passable through to the body cavity, the central lumen is sized for passage of an interventional device therethrough and a portion of the shaft comprises a series of articulating members;    at least one pullwire which extends through at least one of the articulating members to move the portion of the shaft into an articulated position; and    an obturator removably positionable in the central lumen and configured to position the portion of the shaft in a first shape.    
     
     
         2 . An articulatable access system as in  claim 1 , further comprising a locking feature to hold the articulating members in the articulated position to direct the device to the body cavity.  
     
     
         3 . An articulatable access system as in  claim 1 , wherein the articulating members are configured to allow the articulated position to include a primary curve.  
     
     
         4 . An articulatable access system as in  claim 3 , wherein the primary curve has a radius of curvature in the range of approximately 0.125 in. to 1.000 in.  
     
     
         5 . An articulatable access system as in  claim 3 , wherein the articulating members are configured to allow the articulated position to further include a secondary curve.  
     
     
         6 . An articulatable access system as in  claim 5 , wherein the secondary curve has a radius of curvature in the range of approximately 0.050 in. to 0.750 in.  
     
     
         7 . An articulatable access system as in  claim 5 , wherein the primary curve and secondary curve lie in different planes.  
     
     
         8 . An articulatable access system as in  claim 7 , wherein the primary curve and secondary curve lie in substantially orthogonal planes.  
     
     
         9 . An articulatable access system as in  claim 5 , wherein the distal end terminates in a distal tip and the at least one pullwire is fixedly attached to the distal tip to allow the distal tip to move through an angle theta.  
     
     
         10 . An articulatable access system as in  claim 9 , wherein the secondary curve and the angle theta lie in different planes.  
     
     
         11 . An articulatable access system as in  claim 10 , wherein the secondary curve and the angle theta lie in orthogonal planes.  
     
     
         12 . An articulatable access system as in  claim 9 , wherein the primary curve, secondary curve and the angle theta each lie in different planes.  
     
     
         13 . An articulatable access system as in  claim 12 , wherein the primary curve, secondary curve and the angle theta each lie in orthogonal planes.  
     
     
         14 . An articulatable access system as in  claim 1 , wherein distal end is configured to be passable through a blood vessel to the body cavity.  
     
     
         15 . An articulatable access system as in  claim 14 , wherein the body cavity comprises a chamber of a heart and the articulated position directs the central lumen toward a valve.  
     
     
         16 . An articulatable access system as in  claim 1  wherein the obturator is generally straight such that the first shape is generally straight.  
     
     
         17 . An articulatable access system as in  claim 1  wherein the obturator is articulatable such that the first shape has at least one curve.  
     
     
         18 . An articulatable access system as in  claim 1  wherein the obturator is flexible such that the shaft is positionable through the patient's vasculature when the obturator is positioned in the central lumen.  
     
     
         19 . An articulatable access system as in  claim 1 , wherein the at least one pullwire comprises four pullwires.  
     
     
         20 . An articulatable access system as in  claim 1 , wherein the articulating members comprise interfitting domed rings.  
     
     
         21 . An articulatable access system for accessing a body cavity comprising: 
 a shaft having a proximal end, a distal end, and a central lumen therethrough, wherein the distal end is passable through to the body cavity, the central lumen is sized for passage of an interventional device therethrough and a portion of the shaft comprises a series of interfitting articulating members;    at least one pullwire which extends through at least one of the articulating members to move the portion of the shaft into an articulated position;    an obturator removably positionable in the central lumen and configured to position the portion of the shaft in a first shape; and    a locking feature to hold the interfitting articulating members in the articulated position to direct the device to the body cavity.    
     
     
         22 . An articulatable access system as in  claim 21 , wherein each of the articulating members is independently rotateable against an adjacent articulating members.  
     
     
         23 . An articulatable access system as in  claim 21 , wherein the at least one pullwire comprises a first pullwire which is fixedly attached to the shaft at a primary attachment point so that applying tension to the first pullwire deflects the series of interfitting articulating members to form a primary curve.  
     
     
         24 . An articulatable access system as in  claim 23 , wherein the primary curve has a radius of curvature in the range of approximately 0.125 in. to 1.000 in.  
     
     
         25 . An articulatable access system as in  claim 23 , wherein the distal end terminates in a distal tip and the primary attachment point is located at the distal tip.  
     
     
         26 . An articulatable access system as in  claim 23 , wherein the at least one pullwire further comprises a second pullwire which is fixedly attached to the shaft at a secondary attachment point so that applying tension to the second pullwire deflects the series of interfitting articulating members to form a secondary curve.  
     
     
         27 . An articulatable access system as in  claim 26 , wherein the secondary curve has a radius of curvature in the range of approximately 0.050 in. to 0.750 in.  
     
     
         28 . An articulatable access system as in  claim 26 , wherein the at least one pullwire further comprises a third pullwire which is fixedly attached to the shaft at a distal attachment point and so that applying tension to the third pullwire moves the distal end through an angle theta.  
     
     
         29 . An articulatable access system as in  claim 28 , wherein the angle theta is in the range of −100° to +100° degrees.  
     
     
         30 . An articulatable access system as in  claim 21 , wherein each pullwire extends through the central lumen.  
     
     
         31 . An articulatable access system as in  claim 21 , wherein each pullwire extends through a pullwire lumen in a wall the interfitting articulating members.  
     
     
         32 . An articulatable access system as in  claim 31  wherein the pullwire lumen is oblong.  
     
     
         33 . An articulatable access system as in  claim 21 , wherein the at least one pullwire comprises eight pullwires.  
     
     
         34 . An articulatable access system as in  claim 21 , wherein the locking feature comprises means for holding the at least one pullwire in a tensioned position so that the interfitting articulating members are compressed together.  
     
     
         35 . An articulatable access system as in  claim 21 , wherein the locking feature comprises a frictional surface on at least a portion of the articulating members to enhance friction between the articulating members.  
     
     
         36 . An articulatable access system as in  claim 21 , wherein the obturator further comprises a guidewire lumen configured to slidably receive a guidewire.  
     
     
         37 . An articulatable access system as in  claim 21  further comprising a hemostasis valve in communication with the central lumen adapted for inhibiting fluid flow therefrom, the hemostasis valve being configured to receive the interventional device and the obturator.  
     
     
         38 . An access system for accessing a body cavity comprising: 
 a sheath comprising a shaft having a proximal end, a distal end and a central lumen therethrough, wherein the distal end is passable through to the body cavity and a portion of the shaft comprises a series of articulating members which are movable into an articulated position; and    an obturator sized for passage through the central lumen, at least a portion of the obturator being articulatable, wherein articulation of the obturator positions the articulating members of the sheath in the articulated position.    
     
     
         39 . An access system as in  claim 38 , wherein each articulating members is independently rotatable relative to an adjacent articulating members.  
     
     
         40 . An access system as in  claim 38 , further comprise a locking mechanism in the sheath to lock the articulating members in the articulated position.  
     
     
         41 . An access system as in  claim 40 , wherein the locking mechanism comprises a pullwire extending through at least a portion of the articulating members and configured to compress the articulating members together.  
     
     
         42 . An access system as in  claim 38 , wherein the obturator comprises at least one pullwire passing therethrough whereby exerting tension on the pullwire deflects the obturator.  
     
     
         43 . An access system as in  claim 38  wherein the sheath includes an articulation mechanism adapted to articulate the articulating members.  
     
     
         44 . An access system as in  claim 38 , wherein the articulation mechanism comprises at least one pullwire extending through at least a portion of the articulating members.  
     
     
         45 . An access system as in  claim 38 , wherein the articulated position comprises a primary curve.  
     
     
         46 . An access system as in  claim 45 , wherein the articulated position further comprises a secondary curve.  
     
     
         47 . An access system as in  claim 46 , wherein the primary curve and secondary curve lie in different planes.  
     
     
         48 . An access system as in  claim 38 , wherein the obturator is removable such that the sheath remains in the articulated position upon removal of the obturator.  
     
     
         49 . A method of performing a procedure at a treatment site in a body cavity comprising: 
 advancing a sheath to the body cavity, wherein the sheath comprises a shaft having a proximal end, a distal end, and a central lumen therethrough, a portion of the shaft comprising a series of articulating members, an obturator being removably positioned in the central lumen;    articulating the articulating members to move the portion of the shaft into an articulated position;    maintaining the articulating members in the articulated position;    removing the obturator from the central lumen; and    passing an interventional device through the central lumen, wherein the articulated position directs the interventional device to the treatment site.    
     
     
         50 . A method as in  claim 49 , wherein the sheath further comprises at least one pullwire which extends through at least one of the articulating members, and wherein articulating the articulating members comprises applying tension to the at least one pullwire.  
     
     
         51 . A method as in  claim 50 , wherein maintaining the articulating members comprises holding tension in the at least one pullwire.  
     
     
         52 . A method as in  claim 49  wherein the obturator further comprises at least one pullwire, and wherein articulating the articulating members further comprises applying tension to the at least one pullwire to deflect the obturator.  
     
     
         53 . A method as in  claim 49  wherein advancing the sheath comprises slidably positioning the sheath over a guidewire.  
     
     
         54 . A method as in  claim 50 , wherein the articulated position includes a primary curve.  
     
     
         55 . A method as in  claim 54 , wherein the primary curve has a radius of curvature in the range of approximately 0.125 in. to 1.000 in.  
     
     
         56 . A method as in  claim 54 , wherein the articulated position further includes a secondary curve.  
     
     
         57 . A method as in  claim 56 , wherein the secondary curve has a radius of curvature in the range of approximately 0.050 in. to 0.750 in.  
     
     
         58 . A method as in  claim 56 , wherein the primary curve and secondary curve lie in different planes.  
     
     
         59 . A method as in  claim 56 , wherein the distal end terminates in a distal tip and articulating the articulating members includes moving the distal tip through an angle theta to move the portion of the shaft into the articulated position, wherein the angle theta is in the range of −100° to +100° degrees.  
     
     
         60 . A method as in  claim 59 , wherein the primary curve, the secondary curve and the angle theta each lie in different planes.  
     
     
         61 . A method as in  claim 49  wherein the obturator is flexible, and wherein advancing the sheath comprises positioning the sheath through a curved path.  
     
     
         62 . A method as in  claim 49 , wherein the body cavity comprises a left atrium.  
     
     
         63 . A method as in  claim 62 , wherein advancing the sheath comprises positioning the sheath across the interatrial septum.  
     
     
         64 . A method as in  claim 62  wherein the distal end terminates in a distal tip and articulating the articulating members includes moving the portion of the shaft into the articulated position so that the distal tip is directed towards the mitral valve.  
     
     
         65 . A method as in  claim 49 , further comprising: 
 wherein passing the interventional device through the central lumen includes passing the interventional device through an opening in the mitral valve.    
     
     
         66 . A method of accessing a body cavity comprising: 
 advancing a sheath to the body cavity, wherein the sheath comprises a shaft having a proximal end, a distal end, and a central lumen therethrough, and a portion of the shaft comprises a series of articulating members;    passing an obturator through the central lumen;    articulating the obturator to position the articulating members in an articulated position;    locking the articulated members in the articulated position; and    removing the obturator to allow passage of an interventional device through the central lumen, wherein the articulated position directs the interventional device into the body cavity.    
     
     
         67 . A method as in  claim 66 , wherein articulating the obturator further comprises applying forces to the central lumen to position the articulating members.  
     
     
         68 . A method as in  claim 67 , wherein the articulated position includes a primary curve.  
     
     
         69 . A method as in  claim 68 , wherein the articulated position further includes a secondary curve.  
     
     
         70 . A method as in  claim 69 , wherein the primary curve and secondary curve lie in different planes.  
     
     
         71 . A method as in  claim 69 , wherein the distal end terminates in a distal tip and articulating the obturator further comprises moving the distal tip through an angle theta to move the portion of the shaft into the articulated position.  
     
     
         72 . A method as in  claim 71 , wherein the primary curve, secondary curve, and angle theta lie in different planes.  
     
     
         73 . A method as in  claim 66 , wherein the obturator comprises at least one pullwire, wherein articulating the obturator comprises applying tension to the at least one pullwire.  
     
     
         74 . A method as in  claim 66 , wherein the sheath comprises at least one pullwire which extends through at least one of the articulating members, and wherein locking the articulating members comprises holding tension in the at least one pullwire with a locking mechanism.  
     
     
         75 . A method as in  claim 66 , wherein the body lumen comprises a blood vessel.  
     
     
         76 . A method as in  claim 75 , wherein the body cavity comprises a left atrium.  
     
     
         77 . A method as in  claim 76 , wherein advancing the sheath comprises passing the sheath through an intra-atrial septum.  
     
     
         78 . A method as in  claim 77 , wherein the distal end terminates in a distal tip and articulating the articulating members includes moving the portion of the shaft into the articulated position so that the distal tip is directed towards the mitral valve.  
     
     
         79 . A method as in  claim 78 , wherein passing the interventional device through the central lumen includes passing the interventional device through an opening in the mitral valve.  
     
     
         80 . A kit for accessing a body cavity comprising: 
 an articulatable access system comprising 
 a shaft having a proximal end, a distal end, and a central lumen therethrough, wherein the distal end is passable to the body cavity, the central lumen is sized for passage of an interventional device therethrough and a portion of the shaft comprises a series of articulating members;  
 at least one pullwire which extends through at least one of the articulating members to move the portion of the shaft into an articulated position;  
 a locking feature to hold the articulating members in the articulated position to direct the device to the body cavity; and  
   instructions for using the articulatable access system, wherein the instructions set forth method steps including 
 advancing the sheath to the body cavity,  
 applying tension to the at least one pullwire to move the portion of the shaft into the articulated position;  
 maintaining the articulating members in the articulated position; and  
 passing an interventional device through the central lumen, wherein the articulated position directs the interventional device into the body cavity.  
   
     
     
         81 . A kit as in  claim 80 , further comprising the interventional device.  
     
     
         82 . A kit for accessing a body cavity comprising: 
 a sheath comprising a shaft having a proximal end, a distal end and a central lumen therethrough, wherein the distal end is passable to the body cavity and a portion of the shaft comprises a series of articulating members which are lockable in a fixed position; and    instructions for using the sheath, wherein the instructions set forth method steps including 
 advancing the sheath through a body lumen to the body cavity,  
 passing an obturator through the central lumen, wherein the obturator has means for articulating the obturator, wherein articulation of the obturator positions the articulating members in an articulated position which becomes the fixed position upon locking; and  
 articulating the obturator to position the articulating members in the articulated position;  
 locking the articulated members in the articulated position; and  
 removing the obturator to allow passage of an interventional device through the central lumen, wherein the articulated position directs the interventional device into the body cavity.  
   
     
     
         83 . A kit as in  claim 82 , further comprising the obturator.  
     
     
         84 . A kit as in  claim 82 , further comprising the interventional device.