Abstract:
A delivery system for endoluminal delivery of an expandable device comprising a catheter having a proximal end and an opposite distal end configured to support an expandable device, a primary sheath having a delivery position in which the primary sheath constrains the expandable device toward a collapsed configuration suitable for endoluminal delivery, and a handle having an actuator for axially displacing the primary sheath from the delivery position, wherein the handle includes a knob for operating one or more functions of the handle which is initially hidden to prevent use by a user and then revealed as a result of displacement of the primary sheath from delivery position so as to allow subsequent actuation of the knob by the user.

Description:
BACKGROUND 
       [0001]    1. Field 
         [0002]    The present disclosure relates to handles for medical device deployment systems and, more particularly, to handles configured for use in multi-stage deployment systems for expandable medical devices. 
         [0003]    2. Discussion 
         [0004]    Handles for catheter-based deployment systems for endoluminal delivery of expandable devices are well-known in the art. It remains desirable to provide improved handles that can accommodate multi-stage endoluminal delivery and deployment of expandable medical devices, while improving or at least maintaining ease of operation to the clinician. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and together with the description serve to explain the principles of the present disclosure. 
           [0006]      FIGS. 1-5  are cutaway perspective views of a deployment handle for a medical device delivery system, shown in successive stages of use; and 
           [0007]      FIGS. 2A and 3A  are enlarged views of  FIGS. 2 and 3 , respectively. 
       
    
    
     DETAILED DESCRIPTION 
       [0008]    A handle mechanism is disclosed herein for use in connection with delivery systems for endoluminal delivery and deployment of medical devices, such as vascular endoprosthetic implants. A delivery system in accordance with the present disclosure can include a first actuator for selectively actuating a first tubular member and a second actuator for selectively actuating a second tubular member, wherein the second actuator is initially hidden and subsequently presented for use in response to operation of the first actuator. 
         [0009]    Referring to  FIGS. 1-5 , for example, a medical device delivery system is generally indicated at  100 . The delivery system  100  includes a catheter (not shown) having a proximal end and an opposite distal end. The distal end of the catheter is configured for supporting at least one expandable, endoluminally deliverable medical device (not shown). Examples of endoluminally deliverable medical devices include stents, grafts, replacement heart valves, and the like, or any combination thereof. 
         [0010]    The delivery system can include one or more tubular members for releasably constraining the medical device for endoluminal delivery and deployment. The delivery system  100  can, for example, include an elongated first tubular member  200  having a generally cylindrically shaped side wall defining a longitudinally extending lumen (not shown). The first tubular member  200  can have a delivery configuration, in which the medical device is placed within the lumen and constrained by the side wall toward a constrained state suitable for endoluminal delivery of the medical device. The delivery system  100  can also include an elongated second tubular member  300  having a generally cylindrically shaped side wall defining a longitudinally extending lumen (not shown). In the delivery configuration, the second tubular member  300  can be disposed between the first tubular member  200  and the medical device to limit expansion of medical device following removal or displacement of the first tubular member  200  from the delivery configuration. More specifically, the second tubular member  300  can limit expansion of the medical device toward an intermediate state that is larger than the constrained state and yet still smaller than a fully-deployed state, so as to allow axial and rotational positioning of the medical device at the treatment site prior to committing to a full deployment of the medical device. Examples of tubular members include catheters, sheaths, and introducers, or any elongate, tubular member used for supporting and endoluminally delivering a medical device. The tubular members can be constructed using any suitable material or combination of materials, such as polymers, polymer films, and braided wire structures, and any suitable methods known to those having ordinary skill in the art, such as injection molding, extrusion, flow-formed layered wraps, or any combination thereof. 
         [0011]    The delivery system includes a handle having actuators and interfaces, such as knobs, operable to facilitate displacement, removal or actuation of the first and second tubular members from their respective delivery configurations. Such a handle is disclosed in  FIGS. 1-5  and generally indicated at  400 . The handle  400  includes an outer housing  402 . The handle  400  is disposed along and coupled to the proximal end of the catheter. The handle  400  includes a first actuator mechanism  410  and a first knob  420  for manual operation of the first actuator mechanism  410 . The first actuator mechanism  410  includes a follower  412  that is axially displaceable as indicated by the arrow “A” in  FIG. 1  in response to corresponding operation of the first knob  420 . The follower  412  is, in turn, coupled to the first tubular member  200  to cause axial displacement of the first tubular member with the follower  412  during operation of the first knob  420 . The first tubular member  200  is shown in  FIG. 1  in the delivery configuration. In this configuration, the follower  412  is positioned at a distal portion  404  of the handle  400 . Operation of the first knob  420  causes displacement of the first tubular member  200  with the follower  412  from the delivery configuration, as shown in  FIG. 1 , toward the proximal portion  408  of the handle  400 , as shown in  FIGS. 2-4 . 
         [0012]    Still referring to  FIGS. 1-4 , the handle  400  includes a second actuator mechanism  500  and a second knob  520  for manual operation of the second actuator mechanism  500 . As shown in  FIG. 1 , with the first tubular member  200  in the delivery configuration, the second knob  520  is positioned and hidden at a proximal portion  408  of the handle  400 . An arm  522  extends from the second knob  520  toward the distal portion  404  of the handle  400  for engaging the follower  412  during operation of the first actuator mechanism  410 . As shown, in the delivery configuration, an end of the arm  522  can be spaced apart from the follower  412  to allow an initial displacement of the first tubular member  200  without causing corresponding displacement of the second knob  520  from the housing  402 . The second knob  520  and arm  522  are supported by and slidably coupled to the housing  402  to allow displacement of the second knob  520  from the handle housing  402  during movement of the follower  412  with the first tubular member  200  between the positions shown in  FIG. 1  and  FIG. 3 . 
         [0013]    Optionally, a receiver  530  can be provided to support and locate the end of the arm  522  relative to the handle  400 . A distal end  532  of the receiver  530  is configured to engage the follower  412  instead of the end of the arm  522 , as previously discussed. The opposite proximal end  534  of the receiver  530  is defined by a pair of legs  536 . The legs  536  are spaced apart to receive the end of the arm  522  therebetween. 
         [0014]    The actuator mechanisms of the handle can include a variety of mechanisms for moving or actuating the tubular members in response to actuation of respective knobs of the handle. The first actuator mechanism  410  of the handle  400  shown in the figures, for example, includes a helically threaded positioner mechanism  600  for displacing the first tubular member  200  along an axis  610  in response to rotation of the first knob  420  about the axis  610 . 
         [0015]    The positioner mechanism  600  includes a helical slot or guide  620  formed along an inner surface  632  of a tubular wall  630  that extends from the first knob  420 . The wall  630  and, therefore, the helical guide  620  rotate with the first knob  420 . The follower  412  is disposed within a lumen defined by the wall  630 , is engaged with the helical guide  620  and is rotatably constrained with respect to the axis  610 , so that rotation of the helical guide  620  with the first knob  420  causes axial displacement of the follower  412  and the first tubular member  200  therewith, relative to the catheter and the second tubular member  300 . Thus, rotation of the first knob  420  causes or allows progressive expansion of the medical device from the constrained state as the first tubular member  200  is retracted relative to the catheter from the delivery configuration of  FIG. 1  to the various stages of displacement shown in  FIGS. 2-3 . 
         [0016]    Referring to  FIG. 3A , eventual engagement between the proximal end  534  of the receiver  530  and a locating surface  406  in the handle  400  provides a positive stop to prevent further axial displacement of the follower  412 , first tubular member  200  and, in turn, further rotation of the first knob  420 . 
         [0017]    As earlier discussed, expansion of the medical device from the constrained state following removal of the first tubular member  200  is limited to the intermediate state by the second tubular member  300 . Maintaining the medical device at the intermediate state allows axial or rotational positioning of the medical device at the treatment site prior to committing to full deployment. 
         [0018]    The second tubular member  300  can also be axially retracted like the first tubular member. Alternatively, the second tubular member  300  can be formed from a film sleeve held together by an elongated member (not shown), such as a deployment wire or fiber. An example of the latter arrangement is disclosed in U.S. Pat. No. 6,352,561 to Leopold et al., the content of which is incorporated herein by reference in its entirety. In either case, the second actuating mechanism  500  may be provided as a coupling between the second knob  520  and the second tubular member  300  and/or the elongated member, so that removing the second knob  520  from the handle  400  causes removal and/or opening or otherwise actuation of the second tubular member  300 . 
         [0019]    In operation, the first knob  420  is rotated to actuate the threaded positioner mechanism  600  and cause displacement of the first tubular member  200  from the position in  FIG. 1  toward the position in  FIG. 3 . As earlier discussed, the follower  412  is initially spaced apart from the end of the arm  522 . Thus, the second knob  520  remains undisturbed and hidden inside the outer housing  402  near the proximal portion  408  of the handle  400  during initial actuation of the first knob  420  to prevent use of the second knob  520 . 
         [0020]    Displacement of the first tubular member  200  relative to the medical device allows the medical device to expand from the constrained state toward the second tubular member  300 , which limits expansion of the medical device to the intermediate state. In this state, the clinician may choose to make final axial and/or rotational adjustments of the position of the medical device prior to full deployment of the medical device. Once the medical device is placed at a desired position at the treatment site, the clinician can continue to operate the first knob  420 . 
         [0021]    Eventually, as shown in  FIG. 2 , the follower  412  contacts the end of the arm  522  so that continued operation of the first knob  420  and movement of the first tubular member  200  translates into displacement of the second knob  520  from the outer housing  402 , as shown in  FIG. 3 , wherein the second knob  520  is presented for use by the clinician. The second knob  520  and arm  522  can be removed and separated from the handle  400 , as shown in  FIGS. 4 and 5 , to cause displacement and/or otherwise opening of the second tubular member  300  to allow expansion of the medical device toward engagement with surrounding vessel tissue. 
         [0022]    The second knob  520  can include a slot  524  to accommodate use of a guidewire (not shown), which allows the second knob  520  to be substantially coaxial or otherwise near the axis  610 . 
         [0023]    After full deployment of the medical device, the handle  400  can be separated from the first tubular member  200  to allow the first tubular member  200  to be used as an introducer sheath for other medical devices or related surgical implements. 
         [0024]    It will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the spirit or scope of the present disclosure. Thus, it is intended that the present present disclosure cover the modifications and variations of this present disclosure provided they come within the scope of the appended claims and their equivalents.