Patent Publication Number: US-2021161370-A1

Title: Medical devices for agent delivery and related methods of use

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority from U.S. Provisional Application No. 62/943,065, filed Dec. 3, 2019, which is incorporated by reference herein in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to medical systems and devices for delivering pressurized fluids/agents, and more particularly, to devices, methods and tools for delivering the fluid/agent through a channel of a medical device. 
     BACKGROUND 
     In certain medical procedures, it may be necessary to stop or minimize bleeding internal to the body. For example, an endoscopic medical procedure may require hemostasis of bleeding tissue within the gastrointestinal tract, for example in the esophagus, stomach, or intestines. 
     During an endoscopic procedure, a user inserts a sheath of an endoscope into a body lumen of a patient. The user utilizes a handle of the endoscope to control the endoscope during the procedure. Tools are passed through a working channel of the endoscope via, for example, a port in the handle, to deliver treatment at the procedure site near a distal end of the endoscope. The procedure site is remote from the operator. 
     To achieve hemostasis at the remote site, a hemostatic agent may be delivered by a device inserted into the working channel of the endoscope. Agent delivery may be achieved through mechanical systems, for example. Such systems, however, may require numerous steps or actuations to achieve delivery, may increase procedure time, may not achieve a desired rate of agent delivery or a desired dosage of agent, may require the user to readjust positioning of the endoscope to allow passage of the device through the working channel, may result in the agent clogging portions of the delivery device, may result in inconsistent dosing of agent, or may not result in the agent reaching the treatment site deep within the GI tract. The current disclosure may solve one or more of these issues or other issues in the art. 
     SUMMARY OF THE DISCLOSURE 
     Examples of the present disclosure relate to, among other things, agent delivery devices. Each of the examples disclosed herein may include one or more of the features described in connection with the disclosed examples. 
     A delivery device may be configured to deliver an agent to a target tissue through a channel of a medical device, the delivery device may include a body including (a) a coupling region configured to removably attach to a handle of the medical device, and (b) a coupler including an exit port for aligning with a port of the channel, wherein the coupler is configured to mate with the port of the channel; a source of an agent; and a source of pressurized fluid. The body, the source of agent, and the source of pressurized fluid may be arranged to deliver agent and pressurized fluid to the exit port for delivery through the channel. 
     Any of the systems and devices disclosed herein may have any of the following features. The coupling region may include a U-shaped surface configured to mate with a handle of the medical device. The U-shaped surface may include features to inhibit movement between the U-shaped surface and the handle of the medical device. The coupling region may be configured to snap-fit onto the handle of the medical device. The coupling region may include a strap configured to wrap around the handle of the medical device. The handle of the medical device may be a first handle, and the body may include a second handle. The second handle may include an interior portion configured to receive a pressurized fluid container. A longitudinal axis of the second handle may extend substantially parallel to a longitudinal axis of the first handle when the delivery device is coupled to the first handle. The second handle may be spaced from the first handle when the delivery device is coupled to the first handle. The second handle may include grooves configured to accommodate fingers of a user&#39;s hand, and an axis extending through the grooves may be substantially parallel to an axis of the first handle. The coupler may be configured to form a fluid tight seal with the port of the channel such that the exit port is fluidically connected to the channel. The coupler may be a press-fit coupler configured to press fit onto the port to form a fluid tight seal with the port. The coupler may be a first coupler and the exit port may be a first exit port, and the device may further include a first catheter fluidically coupled to the first coupler at a first end; a y-connector fluidically coupled to a second end of the first catheter; a syringe fluidically coupled to the y-connector; and a second coupler including a second exit port for aligning with a port of the channel. The second exit port may be fluidically connected to the first catheter, the y-connector, and the syringe; and the second coupler may be configured to mate with the port of the channel. The device may further include a second catheter including a third coupler, wherein the second catheter is fluidically connected to the y-connector, coupled to the second coupler, and the third coupler is configured to mate with the port of the channel. The handle of the medical device may be a first handle, and the body may include a first proximal portion including a second handle, a first distal portion, and a second proximal portion including the coupling region; and the first proximal portion, the second proximal portion, and the first distal portion may form a U-shape. 
     A delivery device may be configured to deliver an agent to a target tissue through a channel of a medical device, the delivery device may include: 1) a body including (a) a coupling region configured to removably attach to a handle of the medical device, and (b) a coupler including an exit port for aligning with a port of the channel, the coupler may be configured to mate with the port of the channel; 2) an enclosure within the body and configured to store an agent, receive a pressurized fluid, and release a combination of the pressurized fluid and the agent through the exit port; and 3) a regulator within the body and configured to control delivery of pressurized fluid to the enclosure, the regulator including a fluid input port, wherein pressurized fluid and agent flows from the enclosure to the exit port upon coupling a pressurized fluid container to the fluid input port. 
     Any of the systems and devices disclosed herein may have a total volume of pressurized fluid within the pressurized fluid container is configured to deploy a preset amount of the agent through the channel. 
     In other examples, a system configured to deliver an agent to a target tissue through a channel of a medical device, the system may include the medical device comprising a handle, the channel, and a port at an end of the channel; and a delivery device. The delivery device may include a body including (a) a coupling region configured to removably attach to the handle; and (b) a coupler including an exit port for aligning with the port, wherein the coupler is configured to mate with the port; a source of an agent; and a source of pressurized fluid, wherein the body, the source of agent, and the source of pressurized fluid may be arranged to deliver agent and pressurized fluid to the exit port and the channel for delivery to target tissue. 
     Any of the systems and devices disclosed herein may have any of the following features. The delivery device may be configured to deliver agent and pressurized fluid through the channel such that the agent contacts an interior surface of the channel. The system or device may include a liner covering an exterior surface of the medical device and an interior surface of the channel. 
     It may be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. As used herein, the terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. The term “exemplary” is used in the sense of “example,” rather than “ideal.” The term “approximately,” or like terms (e.g., “substantially”), includes values +/−10% of a stated value. The term “distal” refers to a portion farthest away from a user when introducing a device into a patient. By contrast, the term “proximal” refers to a portion closest to the user when placing the device into the patient. Proximal and distal directions are labeled with arrows marked “P” and “D”, respectively, throughout the figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various exemplary embodiments and together with the description, serve to explain the principles of the disclosed embodiments. 
         FIG. 1  is a side view of a delivery system according to an exemplary embodiment. 
         FIG. 2  is a side view of a delivery system according to an exemplary embodiment. 
         FIG. 3  is a side view of a delivery system according to an exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An agent delivery device used in exemplary embodiments may be configured to house an agent within a housing of the delivery device and may be configured to control a rate at which an agent and a fluid leave the delivery device. The delivery device may be configured to house single component agents or multi-component agents. In the case of multi-component agents, the delivery device may be configured to allow for mixing of the components, prior to delivery from the device. Various mechanisms may be utilized in order to pre-pressurize a chamber of the agent and actuate the delivery device to deliver the agent. These mechanisms may include pneumatics, wires, tubes, valves, or any suitable combination thereof. Such agent delivery devices may be configured to couple to primary medical devices and may work cooperatively with primary medical devices to deliver an agent to a target tissue. For example, some embodiments of delivery devices combined with a primary medical device, such as one already positioned within a body lumen and at a target site, may facilitate delivering a hemostatic agent through a channel of the medical device to target tissue within a body of a patient. 
     Referring to  FIG. 1 , a delivery system  100  according to an embodiment is shown. Delivery system  100  may include a medical device  101  and a delivery device  102 . Medical device  101  may be considered a primary medical device, and delivery device  102  may be configured to couple to and operate with medical device  101 . Medical device  101  may be an endoscope, a ureteroscope, a hysteroscope, a uteroscope, a bronchoscope, a colonoscope, a cystoscope, and any other medical device known in the art having a channel therethrough. Medical device  101  may include a handle  103 , a catheter  107 , one or more operating knobs  119 ,  121 , one or more valves/actuators  115 ,  117 , and an umbilicus  105 . A channel  125  may be a working channel, may extend distally from a proximal port  123  through a portion of handle  103 , and may extend through catheter  107  to a distal opening  111  at distal end  109 . Channel  125  may be configured to receive one or more tools, fluids, and/or suction applied at proximal port  123  or through umbilicus  105 . In some examples, medical device  101  may include an imaging unit  113  positioned at a distal end  109  of catheter  107 . In some examples, umbilicus  105  may be electronically coupled to a control unit (not shown) and one or more actuators  115 ,  117  may actuate a command executed by the control unit, such as activating a fluid jet, suction, or activating an image capture mechanism using imaging unit  113 . In some examples, umbilicus  105  may couple one or more fluid sources to medical device  101  and/or may couple one or more vacuum sources to medical device  101 . In some examples, one or more knobs  119 ,  121  may be configured to control movement of distal end  109  of catheter  107 . 
     Delivery device  102  may be configured to removably couple to medical device  101 . Delivery device  102  may include a housing  142 , an enclosure  134  containing an agent  135 , a fluid container  130 , a regulator  132  including a fluid source input port  150 , an actuator  146 , a filter  148 , a coupler  140 , and a plurality of tubes  136 ,  138 . In some examples, fluid container  130  may release pressurized fluid into regulator  132  when coupled to regulator  132 . For example, input port  150  may be configured to pierce fluid container  130  when fluid container  130  is coupled to regulator  132 , releasing pressurized fluid from fluid container  130  into regulator  132 . These components and their functions will be discussed below. These components, however, are exemplary. For example, any of the devices and/or their components that are described in U.S. patent application Ser. No. 16/589,633, filed Oct. 1, 2019, may be used in embodiments. The entire contents of that application are incorporated herein. 
     With reference to  FIG. 1 , fluid container  130  is configured to contain a fluid, such as a gas, e.g., carbon dioxide or any other gas or other fluid known in the art. While shown as a cylindrical enclosure, fluid container  130  may be any shape, such as a torpedo-shape, a sphere, or any other shape known in the art and used for storing fluid. In some examples, fluid container  130  could be a carbon dioxide tank or cylinder typically found in medical settings, such as a hospital. Fluid container  130  may include one or more outer walls defining one or more inner chambers (not shown), the inner chamber(s) configured to contain the fluid. The walls of fluid container  130  may be formed of any material suitable for containing the fluid, such as but not limited to a metal alloy, a ceramic, or other material known in the art. The fluid contained in the inner chamber of fluid container  130  may be under pressure. Accordingly, the walls are formed of a material and/or a thickness suitable to contain the fluid at a pressure of, for example, at least approximately 1000 pounds per square inch (PSI), or approximately 850 PSI. For example, gases which may be contained in fluid container  130  may include carbon dioxide (CO2) having a vapor pressure of approximately 2,000-8,000 kPa at typical device temperatures, or nitrogen (N2) having a vapor pressure less than 40 MPa at typical device temperatures. It will be understood that these gases are examples and are not limiting to the types of gases contained in fluid container  106 . 
     With continued reference to  FIG. 1 , fluid container  130  is attached to regulator  132  at regulator input port  150 . Regulator  132  includes input port  150  and one or more output ports  151 ,  152 . Input port  150  of regulator  132  may be configured to pierce fluid container  130 . One or more tubes  136 ,  138  may fluidically couple one or more output ports  151 ,  152  to enclosure  134  and/or coupler  140 . Regulator  132  may be configured to change the flow rate of fluid exiting fluid container  130  such that fluid flows through tubes  136 ,  138  into enclosure  134  and/or coupler  140  at a selected flow rate. In some examples, fluid may enter enclosure  134  and/or coupler  140  at a flow rate in the inclusive range of four standard liters per minute to twelve standard liters per minute of fluid flow. In some examples, delivery device  102  may be configured to operate with fluid flowing through enclosure  134  and/or coupler  140  at a flow rate in the inclusive range of between five standard liters per minute to ten standard liters per minute. 
     Fluid container  130  may be coupled to regulator  132  via a pull-cord coupling mechanism or a pump mechanism. In some examples, a pull-cord coupling mechanism may be included in delivery device  102  and may include an actuator including a cord and pin, and the pin may engage a fluid cartridge (such as fluid container  130 ) to release fluid from the cartridge when a user pulls the cord. For example, the pin may puncture the cartridge and result in pressurized fluid flowing in device  102 . In other examples, a pump mechanism may be included in device  102  and may be configured to supply pressurized fluid to device  102 , for example by supplying pressurized gas in device  102 . In some examples, device  102  may not include regulator  132  and container  130  may be coupled directed to one or more tubes  136 ,  138  via an input opening similar to input opening  150 . 
     Tube  136  may supply fluid under pressure from fluid container  130  and regulator  132  to enclosure  134 . Enclosure  134  may be cylindrical and may include an interior cavity  137  and a funnel portion  139  at an end of enclosure  134 . Enclosure  134  may be configured to store an agent  135 , such as a powder or liquid medicament, within interior cavity  137 , and interior cavity  137  may be fluidically connected to tube  136 . Funnel portion  139  may include tapered surfaces forming a portion of interior cavity  137  that lead to an opening at an end of enclosure  134 . Funnel portion  139  may be configured to direct agent  135  through the opening into tube  138  (branch  160  of tube  138 ) and coupler  140 . In some examples, enclosure  134  may be configured to gravity feed agent  135  into tube  138  and coupler  140 . Enclosure  134  may be any suitable material known in the art. In some examples, enclosure  134  may be made of a transparent material. 
     Tube  138  may include two branches  160 ,  161 . Branch  160  may extend between and fluidically couple enclosure  134  and coupler  140 . Branch  161  may extend between and fluidically couple regulator  132  and coupler  140 . Branch  160  and branch  161  may merge at, or just prior to, coupler  140 . In some examples, tube  138  may include a filter  148  positioned within a lumen of tube  138 . Filter  148  may be configured to allow fluid flow from the regulator  132  distally through the lumen of tube  138 , and may also be configured to prevent movement of agent  135  proximally through tube  138 , towards regulator  132 . Filter  148  may be configured to prevent movement of agent  135  through tube  138  into regulator  132 . In some examples, filter  148  may be configured to restrict fluid flow through tube  138  by narrowing the diameter of the interior lumen of tube  138 . Delivery device  102  may provide a means to deliver agent  135  to a target tissue by using an existing channel on a medical device, such as channel  125  of medical device  101 , which may reduce procedure time and may simplify a procedure requiring delivery of an agent  135  to tissue. 
     Actuator  146  may be operatively coupled to regulator  132  and may be configured to control the release of pressurized fluid from regulator  132  into tube  136  and/or tube  138 . Actuator  146  may include a trigger, a button, a pressure sensor, a lever, and/or any other actuation mechanism known in the art. In some examples, actuator  146  may be configured to control the release of agent  135  into coupler  140  and into channel  125  of medical device  101  via regulation of pressurized fluid applied to tube  136  and enclosure  134 . Actuator  146  may extend outward from housing  142  to allow a user to actuate actuator  146 . 
     Coupler  140  may be configured to releasably couple to port  123  of channel  125  and fluidically connect tube  138  with channel  125 . In some examples, coupler  140  may form a fluid-tight seal between port  123  and coupler  140  such that fluid may pass through tube  138  into channel  125  without flowing to an area exterior to medical device  101  and delivery device  102 . Coupler  140  may include one or more o-rings which may be polymer, rubber, metal, or any other material. In some examples, coupler  140  may be a press-fit coupler and may form a fluid tight seal with port  123 , and fluidically couple tube  138  to channel  125 . In some examples, coupler  140  may be a quick-release coupler. Coupler  140  may be a gasket seal such as a rubber gasket seal or a snap fitting. In some examples, coupler  140  may be a deformable plastic cap that may be pinched by the user to open, placed on port  123 , and released by the user to close onto port  123 . Coupler  140  may include a screw down component (e.g. may include threads that may couple to port  123  via the threads of the coupler  140  mating with threads of the port  123 ), and the geometry at the distal portion of handle  103  may facilitate coupler  140  coupling to port  123 . 
     Each of enclosure  134 , fluid container  130 , regulator  132 , actuator  146 , filter  148 , coupler  140 , and tubes  136 ,  138  may be fully or partially contained within housing  142 . Housing  142  may be U-shaped (an upside-down “U” as shown in the Figure) and may include a proximal portion  170 , a first distal portion  171 , and a second distal portion  172 . First distal portion  171  (at the bottom right of housing  142 ) may be a handle and may be configured for a user to hold using a hand. In some examples, a central longitudinal axis of first distal portion  171  may be configured to extend parallel to a central longitudinal axis of handle  103 . In some examples, proximal portion  170  may contact and extend radially-outward from handle  103  when delivery device  102  is coupled to handle  103 , and first distal portion  171  may be spaced from handle  103 . First distal portion  171  may include an outer surface ergonomically shaped to accommodate one or more fingers of a user&#39;s hand. For example, each of grooves  171   a  on a surface farthest from device  101  can accommodate four fingers of an operator&#39;s hand, while another hand of the operator holds handle  103  of device  101 . A portion of first distal portion  171  may be removable and may be configured to allow insertion of fluid container  130  into housing  142  for coupling to regulator  132 . All or a portion of fluid container  130  may be positioned within first distal portion  171 . In some examples, a removable cover (not shown) may be at a proximal end of housing  142  and may be configured to allow a user to access enclosure  134 . 
     A coupling region  144  of housing  142  may be configured to removably couple to handle  103  of medical device  101 . In some examples, coupling region  144  may be configured to snap-fit onto handle  103 . Coupling region  144  may include coupler  140  and may be configured to couple to handle  103  such that coupler  140  aligns with proximal opening  123  of channel  125 . That surface receives handle  103  of device  101 . In some examples, coupling region  144  may include a U-shaped surface extending longitudinally in a proximal-distal direction. In some examples, coupling region  144  may include a strap (not shown) configured to wrap around handle  103  and couple delivery device  102  to handle  103 . In some examples, coupling region  144  may be configured to generate an audible sound, such as a “click”, when delivery device  102  has been fixedly coupled to handle  103 . In other embodiments, the inner U-shaped surface of coupling region  144  may include friction enhancing features to inhibit movement between that surface and handle  103 . Coupling region  144  may include a deformable plastic component that may deform and return to its original state, in order to facilitate coupling coupling region  144  to handle  103 , and coupling region  144  may have an original state that matches the form factor of handle  103 . In some examples, coupling region  144  may include a C-shaped surface that may be configured to snap onto handle  103  and extend circumferentially around handle  103 . Coupling region  144  may include a hinged portion (not shown) configured to surround handle  103  and couple to a portion of coupling region  144  once positioned around handle  103 . For example, coupling region  144  may include a hinged portion that has a first state in which the hinge is open and coupling region  144  may be positioned around handle, and a second state when the hinged portion extends around a portion of handle  103  and a portion of the coupling region  144  couples to another, different portion of coupling region  144  (which may form a portion extending circumferentially around handle  103 ). A hinged portion of coupling region  144  may fully encircle the radially-outer surface extending around the central longitudinal axis of handle  103 . In some examples, a hinged portion of coupling region  144  may partially encircle the radially-outer surface of handle  103 , extending around the central longitudinal axis of handle  103 , when coupling region  144  is coupled to handle  103 . 
     In operation, if delivery device is not already loaded with an enclosure  134  with agent  135 , a user may first insert an agent  135  into enclosure  134  of delivery device  102 . The user may then, in some examples, couple fluid container  130  to regulator  132 . The user may then couple delivery device  102  to medical device  101  by, in some examples, pushing coupling region  144  towards handle  103 , or in any other way described above. The user may then, in some examples, move delivery device  102  proximally and/or distally until coupler  140  fluidically couples to port  123  of channel  125 , in any of the ways described above. If device  101  has not already been inserted into the patient with distal opening proximate target tissue, the user may then position distal opening  111  of channel  125  proximate to target tissue of a patient, for example target tissue within a body lumen of a patient. Once distal opening  111  is positioned proximate to or at the target tissue, the user may actuate actuator  146 . By actuating actuator  146 , regulator  132  may initiate fluid flow from fluid container  130  through regulator  132  and into tube  136 . Fluid may then flow from tube  136  through enclosure  134 . When fluid flows into enclosure  134 , agent  135  may be moved in the direction of fluid flow and carried through tube  138  and coupler  140 , and into port  123  and channel  125 . Agent  135  may then be deployed through channel  125  and propelled out of distal opening  111  towards the target tissue via the fluid flow. In some examples, after delivering agent  135  to target tissue, a user may then disconnect delivery device  102  from handle  101  and clean channel  125  by extending a wire brush or other cleaning brush through channel  125 , or supplying an irrigation fluid through channel  125 . A user may then re-couple delivery device  102  to handle  103 , and continue delivering agent  135  to target tissue through channel  125 . 
     In some examples, medical device  101  may include a suction channel including a proximal port similar to proximal opening  123  or extending through umbilicus  105  to a suction enclosure, for example. To operate delivery device  102  with such a suction channel, the user may first press an actuator  115 ,  117  to prevent suction from flowing through the suction channel. The user may then couple delivery device  102  to the proximal port of the working channel for delivery of agent  135 , as described above. By first turning off the application of suction to the suction channel, and thereby preventing suction through channel  125 , the user may prevent agent  135  from coming into contact with bodily fluids and may avoid clogging of channel  125  while delivering agent  135  through channel  125 . 
     In other examples, a user may initiate fluid flow through delivery device  102  when fluid container  130  is coupled to regulator  132 , and a user does not need to actuate actuator  146  or otherwise adjust the deployment of agent  135  through channel  125  via fluid flow from fluid container  130 . The actuation of delivery device  102  through coupling fluid container  130  to regulator  132  (for example, piercing a carbon dioxide container by coupling it to regulator  132 ) provides a means to deliver agent  135  to target tissue without the need for actuator  146  and may produce a single shot of agent  135  to target tissue. In some examples, delivery device  102  may not include regulator  107  and may not include actuator  146 . In some examples, all of or the majority of agent  135  may be moved out of enclosure  134  when fluid container  130  is coupled to regulator  132 . The volume of fluid container  130  may be configured to deploy a selected amount of agent  135  using delivery device  102 . 
       FIG. 2  shows an alternative embodiment of a delivery system  200  similar to delivery system  100 . Delivery system  200  may include medical device  201  and delivery device  202 . Medical device  201  may include handle  203 , catheter  207 , and channel  225  including proximal opening  223 , like device  101 . Delivery device  202  may include fluid container  230 , regulator  232 , and enclosure  234 , like device  102 . Any of the features described herein above regarding delivery system  100 , medical device  101 , and delivery device  102  may be included in delivery system  200 , medical device  201 , and delivery device  202 . 
     Delivery system  200  may also include a catheter  256  (e.g. a tube) extending from an output port  280 , which may or may not include a coupler similar to coupler  138 . Catheter  256  may extend from output port  280  to a y-connector  250 , and an end of catheter  256  may fluidically couple to y-connector  250 . Y-connector  250  may also be fluidically coupled to a second catheter  254  (e.g. a tube) extending from y-connector  250  to a syringe  260 . Y-connector  250  may also be fluidically coupled to a third catheter  252  (e.g. a tube) extending from y-connector  250  to port  223  of channel  225 . In some examples, an end of third catheter  252  may include a coupler similar to coupler  138  described herein above and may be configured to fluidically couple to port  223  of channel  225 . In other examples of delivery system  200 , y-connector  250  may be directly coupled to port  223  of channel  225  and may not include third catheter  252 . 
     Syringe  260  may be configured to push fluid through second catheter  254 , y-connector  250 , third catheter  252 , and into channel  225  through port  223 . Syringe  260  may be configured to supply fluid to wash channel  225 . In some examples, a user may deploy fluid into channel  225  via syringe  260  after delivering an agent from delivery device  202  through channel  225 . Syringe  260  may provide a user a means to wash channel  225  immediately after delivery of an agent from delivery device  202  through channel  225  to target tissue of a patient. In some examples, syringe  260  may be configured to facilitate removal of a clog formed within channel  225 , such as a build up of agent  135  within channel  225 . 
       FIG. 3  shows an alternative embodiment of a delivery system  300 . Delivery system  300  may include medical device  301 , delivery device  302 , and syringe  360 . Medical device  301  may include handle  303 , catheter  307 , and channel  325  including proximal opening  323 . Delivery device  302  may include fluid container  330 , regulator  332 , and enclosure  334 . Any of the features described herein above regarding delivery systems  100 ,  200 , medical devices  101 ,  201 , and delivery devices  102 ,  202  may be included in delivery system  300 , medical device  301 , and delivery device  302 . 
     Delivery system  300  also includes a medical device liner  370  extending longitudinally around catheter  307  and a distal portion of handle  303  including port  323 . Medical device liner  370  may also extend through channel  325  such that portions of liner  370  are adjacent to the interior surface of channel  325 . Medical device liner  370  may envelope a portion of medical device  301 , including all of catheter  307 , and may cover the exterior surface of that portion of medical device  301 . In some examples, medical device liner  370  may include two cylindrical sleeve-like portions with a first portion configured to cover the exterior portion of catheter  307  and handle  303 , and a second portion configured to cover, or otherwise line, the interior surface of channel  325 . The first and second portions of device liner  370  may be connected at a distal end portion configured to cover distal tip  309 . The second portion of device liner  370  (the portion within channel  325 ) may be configured to be back-fed through channel  325  from distal end  309 . A portion of device liner  370  may be configured to removably couple to port  323 . Medical device liner  370  may be configured to protect exterior portions of medical device  301  and also protect interior surfaces of channel  325  from abrasion that may be caused by moving agents through channel  325 . Medical device liner  370  may be disposable and may be made of any suitable flexible material known in the art. In some examples, medical device liner  370  may be made of one or more of plastic, polymer, and pebax. Liner  370  may be fastened to proximal opening  323  via heat shrink, reflow of plastic components, or a barb fitting. 
     Unless described otherwise, the structural elements of medical devices  101 ,  201 ,  301  and delivery devices  102 ,  202 ,  302  may be any material known in the art, including but not limited to a metal alloy, a ceramic, and/or a resin. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed device without departing from the scope of the disclosure. Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.