Patent Publication Number: US-11648357-B2

Title: Methods, systems, and devices for sealing and flusing a delivery system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. patent application Ser. No. 15/661,988, filed Jul. 27, 2017 and titled “Methods, Systems, and Devices for Sealing and Flushing a Delivery System,” which claims the benefit of and priority to: U.S. Provisional Patent Application Ser. No. 62/380,888, filed Aug. 29, 2016 and titled “Methods, Systems, and Devices for Sealing and Flushing a Delivery System”; and U.S. Provisional Patent Application Ser. No. 62/436,926, filed Dec. 20, 2016 and titled “Methods, Systems, and Devices for Sealing and Flushing a Delivery System,” the disclosures of which are incorporated herein by references in their entireties. 
    
    
     BACKGROUND OF THE DISCLOSURE 
     1. The Field of the Disclosure 
     The present disclosure generally relates to methods, systems, and devices for sealing and flushing a delivery system or delivery catheter. 
     2. The Relevant Technology 
     Intravascular medical procedures allow the performance of therapeutic treatments in a variety of locations within a patient&#39;s body while requiring only relatively small access incisions. An intravascular procedure may, for example, eliminate the need for open-heart surgery, reducing risks, costs, and time associated with an open-heart procedure. The intravascular procedure also enables faster recovery times with lower associated costs and risks of complication. An example of an intravascular procedure that significantly reduces procedure and recovery time and cost over conventional open surgery is a heart valve replacement or repair procedure. An artificial valve is guided to the heart through the patient&#39;s vasculature. For example, a catheter is inserted into the patient&#39;s vasculature and directed to the inferior vena cava. The catheter is then urged through the inferior vena cava toward the heart by applying force longitudinally to the catheter. Upon entering the heart from the inferior vena cava, the catheter enters the right atrium. The distal end of the catheter may be deflected by one or more deflecting mechanisms, which can be achieved by tension cable, or other mechanisms positioned inside the catheter. Precise control of the distal end of the catheter allows for more reliable and faster positioning of a medical device and/or implant and other improvements in the procedures. 
     An intravascularly delivered device needs to be placed precisely to ensure a correct positioning of the medical device, which is essential for its functionality, as the device may be difficult to reposition after the device is fully deployed from the delivery system. Additionally, the ability to recapture a partially deployed device is desirable in the event that the distal end of the catheter moves relative to the target location and compromises the precise positioning of the device. 
     The expansion and/or recapture of the device requires the collapse of one or more movable or deformable portions of the device. The one or more movable or deformable portions expand and/or collapse toward the longitudinal axis of a sheath during longitudinal movement of the sheath over the transverse exterior of the device. Proximal movement of the sheath relative to the device allows the device to expand beyond a diameter of the sheath. Distal movement of the sheath relative to the device constrains the device in the tip of the sheath. More rigid and/or robust devices with a high outwards force require a stiffer sheath and/or greater longitudinal forces to move the sheath relative to the device. Increasing the stiffness of the sheath is undesirable during intravascular procedures since a stiff device might not be able to be delivered through a tortuous anatomy. 
     BRIEF SUMMARY OF THE DISCLOSURE 
     Provided are sealing and flushing methods, systems, and devices to ensure that no air or unwanted fluid is trapped in a delivery device when it will be delivered through the vasculature of a patient. For instance, one embodiment includes a method for sealing and flushing a delivery member. The method includes sealing one or more lumens of the delivery member and flushing a fluid from the one or more lumens. In some embodiments, the flushing is done with CO 2 . 
     According to another embodiment, a method for sealing and flushing a delivery member includes sealing (i) a guide wire lumen, (ii) at least one suture lumen of a suture catheter which receives the guide wire lumen, (iii) a delivery catheter disposed about both the suture catheter and the guide wire lumen, and (iv) an outer sheath disposed about the delivery catheter. The method also includes flushing a fluid from the guide wire lumen, the at least one suture lumen, a lumen associated with the delivery catheter, and a lumen of the outer sheath. 
     According to another embodiment, an interventional device delivery system includes a handle assembly and a delivery member. The handle assembly includes a catheter holder with a passageway therethrough. A flush block is associated with the catheter holder and has a flush port and a flush chamber. The delivery member is associated with the handle assembly and includes a plurality of catheters. At least one of the catheters has a proximal end disposed within the passageway in the catheter holder and is in fluid communication with the flush chamber. 
     Additional features and advantages will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the embodiments disclosed herein. The objects and advantages of the embodiments disclosed herein will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing brief summary and the following detailed description are exemplary and explanatory only and are not restrictive of the embodiments disclosed herein or as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order to describe various features and concepts of the present disclosure, a more particular description of certain subject matter will be rendered by reference to specific embodiments which are illustrated in the appended drawings. Understanding that these figures depict just some example embodiments and are not to be considered to be limiting in scope, various embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: 
         FIG.  1    illustrates a delivery system configured for delivering, positioning, and deploying an interventional device, the delivery system including a handle assembly coupled to a delivery member; 
         FIG.  2 - 1    illustrates a cross-section of the delivery member, showing various nested components of the delivery member, including an outer sheath, a steering catheter, a delivery catheter, a suture catheter, and a guidewire tube; 
         FIG.  2 - 2    illustrates another cross-section of the delivery member; 
         FIG.  3    illustrates a cross-section of a portion of the delivery system where a flushing fluid or gas can be introduced to flush the delivery member; 
         FIG.  3 - 1    illustrates a cross-section of a catheter holder that is usable with the handle assembly of  FIG.  1   ; 
         FIG.  4    illustrates an exploded view of a gasket assembly of the handle assembly of  FIG.  1   ; 
         FIG.  5    illustrates a cross-section of a suture catheter of the delivery member of  FIG.  1   ; and 
         FIG.  6    illustrates a cross-section of a portion of the delivery system where a flushing fluid or gas can be introduced into the delivery catheter of the delivery member of  FIG.  1   . 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure is directed to devices, systems, and methods for delivering, positioning, and deploying interventional devices, such as intravascular devices, replacement heart valve devices, valve repair devices, annuloplasty devices, clip devices, and other interventional devices not necessarily configured as a replacement valve. More specifically, the present disclosure is directed to methods, systems, and devices for sealing and flushing a delivery member to ensure that no air or unwanted fluid is trapped in the delivery member when it will be delivered through the vasculature of a patient. 
     As discussed herein, the devices and systems can include a multi-layered elongated delivery member (also referred to herein as simply the elongated member or the delivery member). The delivery member can include a plurality of catheter and/or hypotube members which provide different functionality during operation of the delivery system to enable effective delivery and deployment of the interventional devices. With use a delivery member with multiple components, sufficient flushing of the delivery member is to occur before it can be inserted into the vasculature of the human anatomy. As discussed herein, the disclosed delivery systems and devices enable flushing of the various delivery member elements. 
     With reference to the drawings,  FIG.  1    illustrates an embodiment of a delivery system  100 . As shown, the delivery system  100  includes a handle assembly  102  and an elongated delivery member  104 . The delivery member  104  is coupled to the handle assembly  102  and extends distally from the handle assembly  102 . The delivery member  104  includes a plurality of catheter and/or hypotube members which provide different functionality during operation of the delivery system  100  to enable effective delivery and deployment of an interventional device. 
     The proximal end of an outer sheath  106  (also referred to herein as delivery sheath  106 ) is coupled to an end ring  108 , and the outer sheath  106  extends to a distal end where it is coupled to an interventional device cover  110 . The interventional device cover  110  functions to house an intervention device during delivery of the interventional device to the targeted site. A steering catheter handle  112  is disposed proximal of the end ring  108 . The proximal end of a steering catheter  114  is coupled to the steering catheter handle  112 , and the steering catheter  114  extends distally from the steering catheter handle  112  into the outer sheath  106 . The steering catheter handle  112  includes one or more controls  116  which are operatively coupled to the steering catheter  114  so that manipulation of the controls  116  adjusts the curvature of the steering catheter  114 . Because the steering catheter  114  is nested within the outer sheath  106 , curving of the steering catheter  114  causes corresponding curving/steering in the outer sheath  106 . The illustrated embodiment of the delivery member  104  includes additional components which are not visible in the view of  FIG.  1    but may be seen in the cross-sectional views of  FIGS.  2 - 1  and  2 - 2   . 
       FIG.  2 - 1    illustrates a cross-sectional view of the delivery member  104  transverse to a longitudinal axis thereof and  FIG.  2 - 2    is a cross-sectional view parallel to a longitudinal axis thereof. As shown, the steering catheter  114  is disposed within the outer sheath  106 . A delivery catheter  118  is disposed within the steering catheter  114 . A suture catheter  120  is disposed within the delivery catheter  118 , and a guidewire tube  122  is disposed within the suture catheter  120 . The guidewire tube  122  is configured for receiving a guidewire  124 . 
     Although the particular nested configuration shown in  FIGS.  2 - 1  and  2 - 2    represent one example embodiment, alternative embodiments may include a different concentric arrangement of constituent parts. For example, some embodiments may configure the outermost member with steering functionality, some embodiments may include more than one catheter with steering functionality, and some embodiments may trade the radial positions of the suture catheter  120  and delivery catheter  118 , etcetera. Furthermore, while the illustrated embodiment of a delivery member  104  includes six coaxial members, it will be understood that more or fewer members can be used. Additionally, the members of the delivery member need not be coaxial, but can be at least partially received within one another and can be radially offset. 
     As shown in  FIG.  2 - 1   , the steering catheter  114  includes a plurality of lumens  126  extending through the length of the steering catheter  114 . The lumens  126  may be configured for receiving tension cables which extend between the controls  116  and the distal end of the steering catheter  114 . One or more tension cables may additionally or alternatively be coupled to intermediate sections of the steering catheter  114 . Manipulation of the controls  116  can adjust tension in the tension cables to increase or decrease curvature of the steering catheter  114  at various positions. Although the controls  116  are shown in  FIG.  1    as knobs, alternative embodiments may additionally or alternatively include one or more buttons, sliders, ratcheting mechanisms, or other suitable controls capable of adjusting tension to provide steering. Illustrative structures that can be used as part of the steering catheter handle  112  and or steering catheter  114  are described in U.S. Pat. No. 7,736,388, the disclosure of which is incorporated herein by this reference. 
     Referring again to  FIG.  1   , a delivery catheter holder  128  is disposed proximal of the steering catheter handle  112 . Although not visible in the view of  FIG.  1   , the proximal end of the delivery catheter  118  may be coupled to the delivery catheter holder  128 . The delivery catheter  118  extends distally away from the delivery catheter holder  128  and into the steering catheter  114 . A suture catheter holder  130  is disposed proximal of the delivery catheter holder  128 . Although not visible in  FIG.  1   , the proximal end of the suture catheter  120  may be coupled to the suture catheter holder  130 . The suture catheter  120  extends distally away from the suture catheter holder  130  and into the delivery catheter  118 . 
     An alignment ring  132  and alignment rods  134  provide structural support for maintaining proper alignment of the delivery catheter holder  128  and suture catheter holder  130 , which thereby functions to maintain coaxial alignment of the delivery catheter  118  and suture catheter  120 . A suture catheter control  136  is coupled to the alignment ring  132  and is operatively coupled to the suture catheter holder  130 . Manipulation of the suture catheter control  136  adjusts the relative positioning of the delivery catheter holder  128  and suture catheter holder  130 . In the illustrated embodiment, the suture catheter control  136  operates through threaded engagement with the suture catheter holder  130 , such that rotation of the suture catheter control  136  translates the suture catheter holder  130  relative to the suture catheter control  136  and therefore relative to the delivery catheter holder  128 . Alternative embodiments may additionally or alternatively include one or more of a slider and rail assembly, a ratcheting mechanism, or other suitable means of linear adjustment. 
     The illustrated suture catheter holder  130  also includes a set of tensioner posts  138 . In some embodiments, sutures may extend from the distal end of the suture catheter  120  to the tensioner posts  138 . The sutures may be wrapped around respective tensioner posts  138  such that screwing/unscrewing of the tensioner posts  138  adjusts tension of the coupled sutures. In other embodiments, the sutures are attached to a distal connection ring rather than extend throughout the length of the catheter. In such an embodiment, the tensioner posts  138  may be omitted. 
     A second set of alignment rods  140  extend proximally from the suture catheter holder  130  and connect to an alignment cap  142 . The guidewire tube  122  extends distally through the alignment cap  142  and into the suture catheter  120  at the suture catheter holder  130 . The guidewire tube  122  extends to the distal end of the delivery member  104  where it is attached to a distal tip  144 . 
     The guidewire tube  122  may be selectively translatable relative to the suture catheter holder  130 , so that the guidewire tube  122  and distal tip  144  may be linearly translated relative to the suture catheter  120 . In the illustrated embodiment, the guidewire tube  122  is coupled to a guidewire tube handle  146 . The guidewire tube  122  and guidewire tube handle  146  may be selectively locked relative to the suture catheter holder  130 , such as through a set screw, clamp, or other selective fastener. For example, such a fastening structure may be associated with the alignment cap  142 . 
     When the guidewire tube  122  is linearly locked to the alignment cap  142 , movement of the delivery catheter holder  130  will translate to the alignment cap  142  and to the guidewire tube  122 . The distal tip  144  and suture catheter  120  will thus move together. When unlocked, the guidewire tube  122  (and likewise the distal tip  144 ) may be moved relative to the suture catheter  120 . 
     With use of a delivery member with multiple components, such as delivery member  104 , sufficient flushing of the delivery member is to occur before insertion into the vasculature of the human anatomy. The flushing of some of the delivery member components can be achieved with standard hemostasis valves. For instance, as shown in  FIG.  1   , a hemostasis valve  148  is disposed about the steering catheter  114  and connected to the proximal end of the outer sheath  106 . The hemostasis valve  148  includes a flush port  150  to which a pressurized line may be connected (e.g., with a luer connection) to introduce a flushing fluid or gas between the steering catheter  114  and the outer sheath  106 . Similarly, a hemostasis valve  152  can be connected to the proximal end of the guidewire tube  122  to enable connection of a pressurized line to flush the guidewire tube  122 . 
     To flush the other components of the delivery member  104 , the delivery system  100  may provide one or more additional access points where pressurized line(s) may be connected to introduce a flush fluid or gas into the components of the delivery member  104 . The pathways for some of the lumens or the spaces between adjacent components of the delivery member  104  may be especially challenging since the lumens or spaces have dimensions as small as 0.002 inches. Some of these lumens or spaces are used for sutures and wires that will be connected to an intravascular device, such as a valve or repair device, and will enable the loading of the intravascular device as well as the release. It is suggested that all lumen or spaces before they will be flushed with saline or other flushing fluids can be flushed with CO 2 . The viscosity of a gas compared to a liquid is significantly lower and therefore it will be much easier to replace the entrapped air with a gas like CO 2 . CO 2  is frequently used in medical application and especially in the peripheral vessels as a contrast medium. The gas, when in contact with blood, will dissolve quickly without causing any air emboli. 
     In some embodiments, the entire delivery member  104  is flushed with CO 2  during production and sealed in a gas tight bag or some other flexible or hard-shell container that will be filled with CO 2 . This will guarantee that all lumens in the delivery member  104  will be filled with the inert gas and any air emboli can be eliminated. In yet other embodiments, all flush ports will be closed to ensure that the gas will stay in the lumens and spaces. Following packing in an airtight package, the delivery member  104  can be sterilized using ETO, gamma or e-beam. Before use, the delivery member  104  can optionally be flushed with saline solution or can be used directly with the CO 2  in the lumens or spaces of the delivery member  104 . 
       FIG.  3    illustrates one embodiment of an access point where a flushing fluid or gas can be introduced into the delivery member  104 . The access point is provided at the proximal end of the suture catheter holder  130 . More specifically, a flush block  154  is connected to a proximal end of the suture catheter holder  130  via one or more fasteners  156  (e.g., screws, bolts, pins, clamps, adhesives, etc.). The flush block  154  has a port  158  to which a pressurized line may be connected (e.g., via a luer connection) to introduce a flushing fluid or gas into the flush block  154 . 
     The port  158  is in fluid communication with a flush chamber  160  within the flush block  154 . The distal end of the flush chamber  160  is open to a passageway through the suture catheter holder  130 , while a proximal end of the flush chamber  160  is closed off by a gasket assembly  162 . The interfaces between the flush block  154  and the suture catheter holder  130  and between the flush block the  154  and the gasket assembly  162  can be sealed by one or more seals  164  disposed therebetween. As a result, a flushing fluid or gas introduced into the flush block  154  will pass through the flush chamber  160  and into the suture catheter holder  130  around the guidewire tube  122 , as shown by arrow A in  FIG.  3   . 
     As the flushing fluid or gas flows into the suture catheter holder  130 , the flushing fluid or gas will pass between the guidewire tube  122  and the suture catheter  120 . After the cavities between the guidewire tube  122  and the suture catheter  120  and between the suture catheter  120  and the suture catheter holder  130  have been filled with the flushing fluid or gas, increased pressure (e.g., due to the decreased amount of unfilled space within the delivery member  104  and/or an increase in the pressure used to introduce that flushing fluid or gas into the device) will cause the flushing fluid or gas to pass through lumens (see  FIG.  5   ) within the wall of the suture catheter  120 . 
     In some embodiments, the suture catheter handle  130  may include a vent channel to allow air trapped in the suture catheter handle  130  to be released when a flushing fluid or gas is introduced. For instance, as that shown in  FIG.  3 - 1   , the suture catheter handle  130  includes a vent channel  131  that is in fluid communication with the passageway extending through the suture catheter handle  130  and an exterior of the suture catheter handle  130 . In some embodiments, the vent channel  131  may be a straight channel between the interior and exterior of the suture catheter handle  130 . In other embodiments, the vent channel  131  may have multiple legs, some of which extend longitudinally and some which extend transverse to the suture catheter handle  130 . In still other embodiments, the vent channel  131  may include one or more valves that selectively open or close either under specified pressure differentials or through manual operation. In any event, after the flushing fluid or gas has been introduced into the suture catheter handle  130  as described above and has replaced all air trapped in the suture catheter handle  130 , the vent channel  131  can be closed. Thereafter, the pressure of the flushing fluid or gas can be increased to force the flushing fluid or gas through the components of the delivery member  104 . 
     As noted, the proximal end of the flush chamber  160  is closed off by the gasket assembly  162 .  FIG.  4    illustrates an exploded view of the gasket assembly  162 , showing a proximal plate  166 , a distal plate  168 , and a gasket  170  thereof. In the illustrated embodiment, the proximal plate includes a pocket or recess  172  into which a portion of the gasket  170  is received. With the gasket  170  disposed within the pocket  172 , the proximal and distal plates  166 ,  168  can be connected together (e.g., via fasteners, screws, bolts, adhesives, clamps, etc.) as shown in  FIG.  3   . When the proximal and distal plates  166 ,  168  are connected together, the gasket  170  is compressed therebetween. The gasket  170  can be soft silicon, TPU, FEP, PFTE or any other material suitable for sealing. 
     The interventional device can be connected to the handle assembly with sutures, wires, or other elongate structures. The sutures or wires can run through the wall of the suture catheter  120 . An exemplary cross section of the suture catheter  120  is shown in  FIG.  5   . As can be seen, the suture catheter  120  includes a plurality of lumens  174  extending through the wall thereof in a longitudinal direction. The number of sutures or wires may correspond to the number of lumens  174  in the suture catheter  120 , or vice versa. Each suture can be stitched through the gasket  170 . At its proximal end, the gasket  170  can have a small chamfer to guide the needle or stiletto connected to the suture through the gasket  170 . The stitching of the suture through the gasket  170  can enable a safe sealing. In some embodiments, additional lumens  174  may be provided for additional functions, such as adding a tension cable to be connected to an end ring, tension cable to be connected to the outer sheath  106 , electrical cable to be connected to a circuit board to terminate suture by shorting a circuit and creating heat, or other functions. 
     Additional components of the delivery member  104  can likewise be flushed. For instance,  FIG.  6    illustrates the proximal end of the delivery catheter  118  sealed against the interior of the handle assembly  102  via an O-ring  178 . Flushing fluid or gas introduced to the port  158  discussed above in connection with  FIG.  3    may pass between an exterior of the suture catheter  120  and the interior of the handle assembly  102  until it reaches the proximal end of the delivery catheter  118 . The pressure of the flushing fluid or gas and the seal between the delivery catheter  118  and the interior of the handle assembly  102  may force the flushing fluid or gas into the space between the delivery catheter  118  and the suture catheter  120 . As the flushing fluid or gas passes between the delivery catheter  118  and the suture catheter  120 , any air or other impurities disposed therebetween may be flushed out and replaced with the flushing fluid or gas. 
     While  FIG.  6    has been described as using the flushing fluid or gas introduced through the port  158  (see  FIG.  3   ), it will be appreciated that a flushing fluid or gas may be introduced into the handle assembly  102  through one or more additional ports. The one or more additional ports may allow for flushing fluid or gas to be introduced into the handle assembly  102  and flush the lumens or spaces between various components of the delivery member  104 . For instance, the handle assembly may include a port adjacent to the proximal end of the delivery catheter  118  and through which a flushing fluid or gas may be introduced into the delivery catheter  118 . Similarly, the handle assembly  102  may include a port adjacent to the proximal end of the steering catheter  114  and through which a flushing fluid or gas may be introduced into the steering catheter  114  and/or the lumens  126  thereof. Alternatively, the components of the delivery member  104 , and particularly the proximal ends thereof, may be arranged within the handle assembly  102  such that flushing fluid or gas introduced through the port  158  can pass through one or more of the components of the delivery member  104 . 
     Returning to  FIG.  1   , each of the valves ( 150 ,  152 ) or ports (e.g., port  158 ) through which a flushing fluid or gas is introduced into the delivery system  100  can be connected to a flushing fluid or gas delivery device  180 , such as a CO2MMANDER or other device or system that provides a source of a flushing fluid or gas (e.g., CO 2 ). In some embodiments, such as that illustrated in  FIG.  1   , the delivery device  180  and the delivery system  100  are connected via a plurality of tubes  182  and a manifold  184 . Employing a manifold  184  can allow for selective flushing of all or portions of the delivery member  104 . For instance, to flush all of the components of the delivery member  104 , all of the manifold valves may be opened and flushing fluid or gas may be delivered to all of the valves and ports of the delivery device  100 . In contrast, if only a portion of the delivering member  104  is to be flushed, one or more of the valves of the manifold  184  can be closed such that flushing fluid or gas is delivered only to the desired portions of the delivery member  104 . 
     In some embodiments, the flushing can be automated. For instance, a controller  186  can control the opening and closing of the valves of the manifold  184 . As noted above, the flushing of the various components of the delivery member  104  can be done simultaneously or individually. The controller  186  can control the valves of the manifold  184  to enable the desired flushing. In some embodiments, a sensor can detect pressure changes within the various tubes  182 , indicating that a sufficient flush has been achieved. In addition or as an alternative to a pressure sensor, a flow sensor can be used to indicate when enough volume has been flushed through the delivery member  104  or specific components thereof. In the illustrated embodiment the controller  186  is shown as part of the manifold  184 . In other embodiments, the controller may be part of the delivery device  180  or may be a standalone unit. In any event, after successful flushing, the tubes  182  can be disconnected from the handle assembly and the valves or ports can be closed using a 1 or 2 way stopcock. 
     The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.