Patent Publication Number: US-10786258-B2

Title: Multiple inflation endovascular medical device

Description:
FIELD OF THE DISCLOSURE 
     This disclosure relates generally to occlusion and therapeutic agent delivery devices, systems, and methods, and in particular to occlusion and therapeutic agent delivery devices, systems, and methods configured for repeated inflations of a single expandable member having a longitudinally movable cover to provide multiple treatments or functional surfaces. 
     BACKGROUND 
     Vascular diseases, such as arthrosclerosis, artery occlusion, vascular prophylactic intervention, phlebitis, intimal hyperplasia, plaques, vascular dissections, peripheral artery disease, aneurismal disease, stenosis, and restenosis, are a leading cause of human mortality and morbidity. Vascular diseases arise from a variety of causes, and in some cases, necessitate surgical or endovascular intervention. Trauma to the vascular system can also necessitate surgical intervention to treat the traumatized anatomy. A common treatment for vascular disease is the short-term or long-term contact of a tissue with an endovascular medical device, such as a balloon or a stent, that is coated with a therapeutic agent that prevents or reduces vascular disease at the site of contact. Upon contact of the endovascular medical device with diseased vascular tissue, the therapeutic agent elutes from the endovascular medical device into the surrounding tissue at the site of contact, thereby treating the vascular disease at a local level. The long-term contact, e.g., implantation, of endovascular medical devices including vascular grafts, stent-grafts, and stents, and the short-term contact of vascular medical devices including catheter-based balloons, are often undertaken to treat vascular disease and vascular trauma. 
     The treatment of vascular disease at a local level, rather than a systemic level, is often preferred. Systemic administration of therapeutic agents (e.g., drugs and densified materials) can produce unwanted side effects when compared to the local administration of a therapeutic agent to treat vascular disease. Conventionally, the utilization of drug-coated endovascular medical devices has become a standard technique for the local administration of a drug to a target tissue. For example, drug-coated balloons (DCBs) have been used for the local administration of a drug to a target tissue to treat vascular disease, including coronary artery disease and peripheral artery disease (see, e.g., U.S. Pat. No. 5,102,402, issued to Dror et al. (hereafter “Dror”)). Dror discloses placing a DCB in a blood vessel lumen to treat the vessel wall, inflating the DCB, and contacting an exterior surface of the DCB with the luminal vessel wall to deliver the drug into the blood vessel wall. 
     As described in Dror, many drug-coated endovascular medical devices, however, are configured for a single treatment or therapy via a single inflation of an expandable member having a single uniform functional surface. Conventional devices require an invasive surgical procedure to thread the drug-coated endovascular medical device to a therapeutic site and are suitable for only a single treatment at the site. After the single treatment, the expandable member is typically deflated and the drug-coated endovascular medical device is withdrawn from the body. In some circumstances, however, multiple treatments or multiple treatment surfaces at a therapeutic site may be desired. Accordingly, the need exists for occlusion and therapeutic agent delivery devices, systems, and methods capable of providing repeated treatments at a therapeutic site. 
     BRIEF SUMMARY 
     Various embodiments relate to a medical device including (i) a catheter including a longitudinal axis, a proximal end, a distal end, and a cover lumen extending from the proximal end of the catheter to the distal end of the catheter, and (ii) an expandable member including a proximal end and a distal end. The expandable member is disposed on a distal section of the catheter. The medical device further includes (iii) a cover including a first region and a second region. The first region is disposed along, e.g., overlaps or covers, the expandable member, and the second region extends along a length of the catheter beyond the proximal end of the expandable member toward the proximal end of the catheter. A first end of the cover inverts into the cover lumen adjacent the distal end of the catheter. The medical device further includes (iv) an actuator coupled to the first end of the cover and configured to retract the first end of the cover through the cover lumen towards the proximal end of the catheter along the longitudinal axis of the catheter. 
     In some embodiments, a medical device includes a catheter having a longitudinal axis, a proximal end, a distal end, and a cover lumen extending from the proximal end of the catheter to the distal end of the catheter. The medical device further includes an expandable member including a proximal end and a distal end. The expandable member may be disposed on the catheter. The medical device may further include a cover including a first region, a second region, and a third region. A first end of the cover may invert into the cover lumen. An actuator may be coupled to the first end of the cover and may be configured to move the first end of the cover towards the proximal end of the catheter along the longitudinal axis of the catheter. The first region may include a therapeutic agent disposed on a surface of the first region of the cover. The second region may include at least one aperture through which the expandable member may expand. The third region may include an endoprosthesis. 
     In certain embodiments, the cover includes polytetrafluoroethylene, expanded polytetrafluoroethylene, or expanded copolymers of polytetrafluoroethylene. 
     In various embodiments, the cover may have a length that is at least two times a working length of the expandable member. In some embodiments, a sheath is disposed along at least a portion of the second region of the cover. In some embodiments, the second region of the cover is less distensible than the expandable member. In certain embodiments, the therapeutic agent includes paclitaxel, docetaxel, protaxel, arsenic trioxide, thalidomide, atorvastatin, cerivastatin, fluvastatin, betamethasone diproprionate, dexamethasone21-palmitate, sirolimus, everolimus, zotarolimus, biolimus or temsirolimus. 
     In various embodiments, a medical device includes a catheter, an expandable member, a cover, and an actuator. The catheter may include a proximal end, a distal end, a cover lumen that extends from the distal end to the proximal end of the catheter. The expandable member may be disposed on the catheter and has a working length. The cover may include a plurality of regions and a first end of the cover may be inverted into a cover lumen of the catheter. The cover may have a length that is at least two times the working length of the expandable member. The actuator may be coupled to the first end of the cover and configured to move the first end of the cover towards the proximal end of the catheter along the longitudinal axis of the catheter. 
     In some embodiments, a therapeutic agent is disposed on a first region of the plurality of regions of the cover or a second region of a plurality of regions. 
     In some embodiments, a second therapeutic agent may be disposed on a surface of the other of the first region and the second region of the cover. In still yet other embodiments, a first endoprosthesis may be disposed on a surface of the other of the first region and the second region of the cover, still yet a second endoprosthesis may be disposed on a surface of a third region of the plurality of regions of the cover. In some embodiments, the first endoprosthesis may have a first length and the second endoprosthesis has a second length that may be different from the first length. 
     In certain embodiments, the first therapeutic agent may be different than the second therapeutic agent. In some embodiments, at least one of the first therapeutic agent and the second therapeutic agent comprises a densified material configured to increase a coefficient of friction on the surface of the region it is disposed on. In certain embodiments, the other of the first therapeutic agent and the second therapeutic agent that does not comprise a densisified material may comprise at least one of paclitaxel, docetaxel, protaxel, arsenic trioxide, thalidomide, atorvastatin, cerivastatin, fluvastatin, betamethasone diproprionate, dexamethasone21-palmitate, sirolimus, everolimus, zotarolimus, biolimus or temsirolimus. 
     In some embodiments, the first therapeutic agent and the second therapeutic agent are the same therapeutic agent. In certain embodiments the first therapeutic agent may be at a first dose density and the second therapeutic may be at a second dose density that is different from the first dose density. 
     In various embodiments, a third therapeutic agent is disposed on a surface of a third region of the plurality of regions of the cover, the third therapeutic agent may be different from at least one of the first and second therapeutic agents. In some embodiments, the first region of the plurality of regions has a length that is greater than a working length of the expandable member, and the second region of the plurality of regions may have a length that is also greater than the working length of the expandable member. 
     In some embodiments, a third region of the plurality of regions may include an endoprosthesis. 
     In various embodiments, a medical device includes a catheter, an expandable member, a cover, and an actuator. The catheter may include a longitudinal axis, a proximal end, a distal end, and a cover lumen extending from the proximal end of the catheter to the distal end of the catheter. The expandable member may include a proximal end and a distal end and may be disposed on the catheter. The cover may include a plurality of regions, and a first region of the plurality of regions may have at least one aperture. A first end of the cover may evert into the cover lumen. The actuator may be coupled to the first end of the cover and configured to move the first end of the cover towards the proximal end of the catheter along the longitudinal axis of the catheter. 
     In some embodiments, a second region of the plurality of regions comprises a therapeutic agent disposed on a surface of the second region. 
     In some embodiments, the first region of the plurality of regions is less distensible than the expandable member. 
     In some embodiments, the at least two regions of the plurality of regions each have a length that is at least as long as a working length of the expandable member. 
     In some embodiments, the at least one aperture comprises a portion of the first region that is weaker than the remaining portion of the first region of the plurality of regions. 
     In some embodiments, a second region of the plurality of regions further comprises an endoprosthesis. 
     In various embodiments a medical device includes a catheter, an expandable member, a cover, and an actuator. The catheter may include a longitudinal axis, a proximal end, a distal end, and a cover lumen extending from the proximal end of the catheter to the distal end of the catheter. The expandable member may include a proximal end and a distal end, and a working length. The expandable member may be disposed on the catheter. The cover may include a plurality of regions The actuator may be coupled to a first end of the cover configured to move the first end of the cover towards the proximal end of the catheter along the longitudinal axis of the catheter. 
     In some embodiments, a first region of the plurality of regions and a second region of the plurality of regions each have a length that is at least equal to the working length of the expandable member. 
     In some embodiments, a sheath may be disposed along at least a portion of a first region of the cover, wherein the first region of the cover extends between the proximal end of the expandable member and the proximal end of the catheter. Optionally, the cover may include at least one line that is coupled to the actuator. Optionally, the at least one line may be integral with the cover. 
     In some embodiments, a third region of the plurality of regions may have a length that is at least equal to the working length of the expandable member. 
     In some embodiments, a first region of the plurality of regions has a first nominal diameter, and a second region of the plurality of regions has a second nominal diameter that is different from the first nominal diameter. A third region of the plurality of regions may have a third nominal diameter that may be different from the first and second nominal diameters. 
     In some embodiments, a first region of the plurality of regions is positioned around the expandable member and a second region of the plurality of regions is positioned around the catheter. 
     In various embodiments, a method of treatment includes providing a medical device having an expandable member and a cover. The cover may include a first region and a second region. The method may include inserting the medical device in a peripheral blood vessel and expanding the expandable member with the first region of the cover positioned over the expandable member such that the first region of the cover provides a first treatment to a blood vessel wall. The actuator may be activated to draw the first region into a lumen of the medical device and to position the second region of the cover over the expandable member. The expandable member can be expanded with the second region of the cover over the expandable member such that the second region of the cover provides a second treatment to the blood vessel wall. The first treatment may be different from the second treatment, and each of the first treatment and the second treatment may be provided to the blood vessel wall prior to removing the medical device assembly from the body lumen. 
     In some embodiments, the at least one of the first treatment and the second treatment may include transferring a therapeutic agent to the blood vessel wall. 
     In some embodiments, the second region of the cover includes a plurality of apertures through which an expandable member expands. Providing the second treatment may include contacting and shaving deposits from a surface of blood vessel wall. Optionally, the method may also include expanding the expandable member with a third region of the cover over the expandable member such that the third region of the cover provides a third treatment to the blood vessel wall. Each of the first treatment, the second treatment, and the third treatment may be provided to the blood vessel wall prior to removing the medical device assembly from the blood vessel. 
     In some embodiments, the third treatment may include positioning an endoprosthesis positioned around the third region of the cover into contact with at least a portion of the blood vessel wall. 
     In some embodiments, the first treatment may include transferring a first therapeutic agent to the blood vessel wall, and the second treatment may include transferring a second therapeutic agent to the blood vessel wall, the first therapeutic agent being different from the second therapeutic agent. 
     In some embodiments, the method of treatment may include expanding the expandable member with a third region of the cover over the expandable member such that the third region of the cover provides a third treatment to the blood vessel wall. The third region of the cover may include an endoprosthesis and the third treatment may include deploying the endoprosthesis in the blood vessel wall. In addition, each of the first treatment, the second treatment, and the third treatment may be provided to the blood vessel wall prior to removing the medical device assembly from the body lumen. 
     In some embodiments the first treatment may be performed prior to the third treatment, and the first treatment may include contacting and shaving deposits from a surface of blood vessel wall. 
     In some embodiments, the first treatment may include transferring a first therapeutic agent to the blood vessel wall. 
     In some embodiments, the first treatment is performed prior to the third treatment, and the second treatment may be performed after the third treatment. Optionally, the second region may include an endoprosthesis and the second treatment may include deploying a second endoprosthesis in the blood vessel well. Further, optionally a first diameter the endoprosthesis of the third region is different from a second diameter of the second endoprosthesis of the second region. Also optionally, a first length of the endoprosthesis of the third region may be different from a second length of the second endoprosthesis of the second region. 
     In some embodiments, the second treatment may include transferring a therapeutic agent to the blood vessel wall. 
     In some embodiments, the method includes expanding the expandable member with a fourth region of the cover over the expandable member such that the fourth region of the cover provides a fourth treatment to the blood vessel wall. The first treatment, the second treatment, the third treatment, and the fourth treatment may be provided to the blood vessel wall prior to removing the medical device assembly from the body lumen. 
     In accordance with some aspects, the cover is formed, at least in part, of an expanded fluoropolymer. Optionally, the expanded fluoropolymer includes expanded polytetrafluoroethylene, expanded polytetrafluoroethylene, or an expanded copolymer of polytetrafluoroethylene. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the embodiments of the disclosure provided herein and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the principles of the embodiments of the disclosure. 
         FIG. 1  is perspective view of a medical device including an expandable member assembly and a catheter, in accordance with an embodiment of the disclosure; 
         FIG. 2  is a side cross-sectional view of a distal region of the expandable member assembly, in accordance with an embodiment of the disclosure; 
         FIG. 3  is a front cross-sectional view of the catheter including a cover lumen, in accordance with an embodiment of the disclosure; 
         FIG. 4  is a side cross-sectional view of a proximal region of the expandable member assembly, in accordance with an embodiment of the disclosure; 
         FIG. 5A  is a side view of the expandable member assembly including a first region of a cover having a first coating or treatment surface disposed along the expandable member in an inflated state, in accordance with an embodiment of the disclosure; 
         FIG. 5B  is a side view of the expandable member assembly including a second region of the cover having a second coating or treatment surface disposed along the expandable member in an inflated state, in accordance with an embodiment of the disclosure; 
         FIG. 5C  is a side view of the expandable member assembly including a third region of the cover having a third coating or treatment surface disposed along the expandable member in an inflated state, in accordance with an embodiment of the disclosure; 
         FIG. 6A  is a side view of the expandable member assembly including a first region of the cover disposed along the expandable member in an inflated state at a first nominal diameter, in accordance with an embodiment of the disclosure; 
         FIG. 6B  is a side view of the expandable member assembly including a second region of the cover disposed along the expandable member in an inflated state at a second nominal diameter, in accordance with an embodiment of the disclosure; 
         FIG. 6C  is a side view of the expandable member assembly including a third region of the cover disposed along the expandable member in an inflated state at a third nominal diameter, in accordance with an embodiment of the disclosure; 
         FIG. 7A  is a side view of the expandable member assembly including a first region of the cover having apertures disposed along the expandable member in an inflated state, in accordance with an embodiment of the disclosure; 
         FIG. 7B  is a side view of the expandable member assembly including a second region of the cover having scores disposed along the expandable member in an inflated state, in accordance with an embodiment of the disclosure; 
         FIG. 7C  is a side view of the expandable member assembly including a third region of the cover disposed along the expandable member in a first inflated state, in accordance with an embodiment of the disclosure; 
         FIG. 7D  is a side view of the expandable member assembly including the third region of the cover disposed along the expandable member in a second inflated state, in accordance with an embodiment of the disclosure; 
         FIG. 8A  is a side view of an expandable member assembly including a first region of the cover having apertures disposed along an expandable member in an inflated state, in accordance with an embodiment of the disclosure; 
         FIG. 8B  is a side view of the expandable member assembly including a second region of the cover having a coating disposed along the expandable member in an inflated state, in accordance with an embodiment of the disclosure; 
         FIG. 9  is a front view of a catheter, in accordance with an embodiment of the disclosure; 
         FIG. 10A  is a cross-sectional front view of a medical device that includes an expandable member in a first inflated position, in accordance with an embodiment of the disclosure; 
         FIG. 10B  is a cross-sectional front view of the medical device with the expandable member in a second inflated position, in accordance with an embodiment of the disclosure; and 
         FIG. 11  is a side view of an expandable member assembly including a first region of the cover about the expandable member, in accordance with an embodiment of the disclosure. 
         FIG. 12  is a side view of an expandable member assembly including a cover disposed along an expandable member, in accordance with an embodiment of the disclosure. 
         FIG. 13  is a side view of an expandable member assembly including a cover disposed along an expandable member, in accordance with an embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     I. Introduction 
     Various embodiments described herein are directed to occlusion and therapeutic agent delivery devices, systems, and methods capable of deploying an expandable member within a lumen of a tubular structure (e.g., a blood vessel or duct) to treat a site on the tubular structure, and inflating the expandable member to a nominal diameter such that a surface of the expandable member (or a cover on the expandable member) contacts a wall of the tubular structure to deliver the treatment or therapy to the site on the tubular structure. A problem associated with many conventional occlusion and therapeutic agent delivery devices, systems, and methods is that the expandable member (or the cover on the expandable member) is only configured with a single treatment surface or therapy. After the single treatment surface or therapy is administered, the expandable member is typically deflated and the device is withdrawn from the body. 
     Various embodiments described herein are directed to occlusion and therapeutic agent delivery devices, systems, and methods capable of repeated inflations of a single expandable member having a longitudinally movable cover to provide multiple treatments or functional surfaces. For example, various embodiments of the present disclosure are directed to a medical device that includes (i) a catheter including a longitudinal axis, a proximal end, a distal end, and a cover lumen extending from the proximal end of the catheter to the distal end of the catheter, and (ii) an expandable member including a proximal end and a distal end. The expandable member is disposed on a distal section of the catheter. The medical device further includes (iii) a cover including a first region and a second region. The first region is disposed along, e.g., overlaps or covers, the expandable member, the second region extends along a length of the catheter beyond the proximal end of the expandable member towards the proximal end of the catheter, and a first end of the cover inverts into the cover lumen. The medical device further includes (iv) an actuator coupled to the first end of the cover and configured to retract the first end of the cover through the cover lumen towards the proximal end of the catheter along the longitudinal axis of the catheter. As a portion of the cover is retracted into the cover lumen, an unretracted outer portion of the cover is pulled in the distal direction toward the distal end of the catheter, such that a previously undeployed region of the cover is positioned over the expandable member for subsequent treatment or therapy at the therapeutic site. 
     Advantageously, this approach provides occlusion and therapeutic agent delivery devices, systems, and methods that are capable of repeated inflations of a single expandable member having a longitudinally movable cover to provide multiple treatments or functional surfaces at a treatment site. For example, the movable cover may be segmented into a plurality of regions, each region having a specific therapeutic agent coating (e.g., same or different drug and/or dose of drug), inflation profile (e.g., same or different nominal diameter), functional surface (e.g., same or different surface texture and/or surface features), and or endoprosthesis device (e.g., an expandable stent, a self-expanding stent, one or more stents having the same or different diameters and/or lengths). Moreover, the therapeutic agent delivery devices, systems, and methods optionally include a cylindrical sheath disposed along at least a portion of the movable cover that overlaps and protects one or more regions of the movable cover during deployment to the therapeutic site. The sheath may further protect one or more regions of the movable cover while the expandable member expands and radially presses an exposed region covering the expandable member against a therapeutic site. 
     II. Definitions 
     As used herein, the terms “a” and “an” are defined as one or more unless this disclosure explicitly requires otherwise. 
     The preposition “between,” when used to define a range of values (e.g., between x and y) means that the range includes the end points (e.g., x and y) of the given range and the values between the end points. 
     As used herein, the term “coating” refers to one or more materials disposed on the surface of a substrate. In the present disclosure the substrate may include the structural layer or substrate or expandable member or cover. The coating may lie completely on the surface or may be incorporated, in whole or in part, within the openings or pores present in a substrate. The latter coating configuration is commonly referred to in the art as “imbibed” or “filled” materials. 
     As used herein, the terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, any of the present devices, systems, and methods that “comprises,” “has,” “includes” or “contains” one or more elements possesses those one or more elements, but is not limited to possessing only those one or more elements. Likewise, an element of a device, system, or method that “comprises,” “has,” “includes” or “contains” one or more features possesses those one or more features, but is not limited to possessing only those one or more features. 
     Any of the present devices, systems, and methods can consist of or consist essentially of—rather than comprise/include/contain/have—any of the described elements and/or features and/or steps. Thus, in any of the claims, the term “consisting of” or “consisting essentially of” can be substituted for any of the open-ended linking verbs recited above, in order to change the scope of a given claim from what it would otherwise be using the open-ended linking verb. 
     As used herein, “delivery diameter” refers to the diameter or cross-sectional width of a tubular form that is substantially equal to or slightly larger than the diameter or cross-sectional width of the tubular form during delivery through the vasculature, pre-inflation. 
     As used herein, “deployment” refers to the actuation or placement of a device at a treatment or therapeutic site. Deployment process can occurs in stages. 
     As used herein, the terms “first”, “second”, “third” . . . “sixth”, etc. identify and distinguish particular regions or components of the occlusion and therapeutic agent delivery devices and are not used herein to indicate a specific order of deployment, unless otherwise stated. 
     As used herein, the term “invert” refers to a material doubling back on itself internally or externally. 
     As used herein, the terms “micropores” and “microporous” refer to openings in materials, for example the area between expanded polytetrafluoroethylene (ePTFE), nodes and fibrils. Usually, as in the case of ePTFE, these micropores contain air when the material is not “wetted”. 
     As used herein, a “non-compliant” balloon is one that has less than about 10% diametric growth when inflated from the nominal inflation pressure to the rated burst pressure. 
     As used herein, “nominal diameter” means the approximate diameter of the balloon at the nominal inflation pressure. Beyond this state, pressure increases (e.g., up to the rated burst pressure) result in less than a 20% increase in diameter, less than a 15% increase in diameter, or less than a 10% increase in diameter. Typically, the nominal diameter is the labeled diameter as indicated on the instructions for the end user, e.g., a clinician. 
     As used herein, the terms “proximal” and “distal” are similarly used for the purpose of identifying and distinguishing particular regions or components of the occlusion and therapeutic agent delivery devices. “Proximal” is used to identify a location or portion of the assembly that when inserted is closer to a physician or clinician and/or is closer to an entry site through which the assembly is passed. “Distal” is used to identify a location or portion of the assembly that is farther from the physician or clinician and/or farther from the entry site through which the assembly is passed. The term “longitudinal” refers to the lengthwise direction relative to the device, and the term “lateral” refers to a direction perpendicular to the longitudinal direction, e.g., the width of a device. 
     As used herein, a “semi-compliant” balloon is one that has less than about 20% diametric growth (e.g., less than a 20% increase in the balloon diameter relative to the nominal diameter) when inflated from the nominal inflation pressure to the rated burst pressure. 
     As used herein, the terms “substantially,” “approximately” and “about” are defined as being largely but not necessarily wholly what is specified (and include wholly what is specified) as understood by one of ordinary skill in the art. In any disclosed embodiment, the term “substantially,” “approximately,” or “about” may be substituted with “within [a percentage] of” what is specified, where the percentage includes 0.1, 1, 5, and 10 percent. The term “majorly” indicates at least half. 
     As used herein, the term “variably permeable microstructure” refers to a structure or material with a resistance to fluid transfer at a first state that is greater than the resistance of the same structure or material at a second state with such resistance varying between the two states. One skilled in the art will appreciate various methods which characterize the change in permeability from testing at a first state and comparing to testing done at a second state. These methods include, but are not limited to, characterizations of air or liquid flux across the microstructure at a given pressure differential, characterization which determines the pressure differential at which different fluids strike through the microstructure such as Water Entry Pressure or Bubble Point, characterization of porosity, and visual characterization such as inter-nodal or inter-fibril spacing as measured from an image (e.g. from a scanning electron microscope or light microscope). One non-limiting embodiment of a variable permeable material comprises a material that has a substantially closed microstructure when the material is not under a strain and has a more open microstructure when the material is strained. 
     As used herein, the terms “wet”, “wet-out” and “wetted” refer to the displacement of air in a microporous material by a fluid. Wetting of a material lowers the resistance to subsequent fluid transfer and facilitates the flow of fluids though the microporous material. Furthermore, these microporous materials are intended to be open cell structures, meaning the micropores are interconnected, and not closed cell structures. This allows fluid to flow through the material. Capillary effects may also play an important role in fluid flow though the material as wetting occurs, especially for highly porous materials with small interconnected pores. Wetting can be accomplished with the aid of one or more surfactants added to the fluid. The surfactant can absorb onto the fluid-vapor, solid-fluid, and solid-vapor interfaces, which in turn modifies the wetting behavior of hydrophobic materials. The wetting will also depend on the viscosity to the fluid 
     As used herein, the term “working length” is the length of the substantially straight body section of an expandable member (e.g., a balloon), which corresponds to the approximate length of the expandable member between the opposed shoulder/tapered portions as shown by “W” in  FIG. 1 . 
     III. Occlusion and Therapeutic Agent Delivery Devices and Systems 
       FIG. 1  shows a medical device  5  that includes an expandable member assembly  10  and a catheter  15 . In various embodiments, the catheter  15  has a cylindrical form and comprises a longitudinal axis  17 , a proximal end  18 , a distal end  19 , and a cover lumen  32  optionally extending from the proximal end  18  to the distal end  19 . The expandable member assembly  10  comprises an inflatable member or expandable member  20  positioned on a distal section  16  of the catheter  15 . As shown, the expandable member  20  includes a body section  21  that may be substantially cylindrical along a working length (W), two opposed leg portions  22 , and shoulder/tapered portions  23  that may be integrally connected to the body section  21  and the two opposed leg portions  22 . The body section  21 , the leg portions  22 , and the shoulder/tapered portions  23  define an overall length of the expandable member  20  from a proximal end  24  to a distal end  25 . In some embodiments, the expandable member  20  comprises a thermoplastic polymeric material that includes urethanes, PET, PEBAX, polytetrafluoroethylene (PTFE), polyamides such as nylon 12, nylon 11, nylon 9, nylon 6/9, nylon 6/6, and combinations thereof. 
     The medical device  5  has a first section S 1  that extends from a distal end  19  of the catheter  15  to the proximal end  24  of the expandable member  20 . The medical device  5  also has a second section S 2  that extends from the proximal end  24  of the expandable member  20  to the proximal end  18  of the catheter  15 . The medical device  5  also has a third section S 3  that corresponds to a length of the catheter  15  that extends from the distal end  19  of the catheter  15  to the proximal end  18  of the catheter  15  within the cover lumen  32  of the catheter  15 . 
     The working length (W) of the expandable member  20  may be from about 10 mm to about 400 mm, from about 10 mm to about 250 mm, or from about 10 mm to 150 mm. Similarly, the nominal diameter of the expandable member  20  can be from about 2 mm to about 100 mm, from about 2 mm to about 60 mm, or from about 2 mm to about 30 mm. By way of example, the expandable member  20  can have a nominal diameter of from about 4 mm to about 10 mm and a working length (W) of from about 25 mm to about 50 mm, or a nominal diameter of from about 6 mm to about 25 mm and working length (W) of from about 15 mm to about 75 mm. As should be understood, the expandable member  20  may have any appropriate dimension and size for the clinical application. 
     In various embodiments, the expandable member  20  is attached or mounted to the catheter  15  at the leg portions  22  such that the catheter  15  is in fluid communication with the expandable member  20 . For example, the catheter  15  may comprise one or more lumens, one of which may be in fluid communication, optionally through an orifice in the catheter, with a chamber of the expandable member  20  for supplying inflation fluid to inflate the expandable member  20  balloon in a tubular structure such as a patient&#39;s vasculature. The catheter  15  may be coupled, for example via a port  26 , to any suitable inflation-deflation device, such as a syringe, an indeflator, pump or any other apparatus for conducting inflation fluid through the catheter  15  and into the expandable member  20 . In accordance with some embodiments, the inflation-deflation device may push fluid into and retract fluid from the chamber of the expandable member  20  via the catheter  15  to inflate and deflate the expandable member  20 . To assist in the control of the diameter of a balloon, the catheter  15  and the expandable member  20  may be aspirated (remove air and replace it with a fluid) prior to inflating the expandable member  20  with inflation fluid. The inflation fluid used to aspirate the catheter  15  and the expandable member  20  and/or to inflate the expandable member  20  may comprise a contrast (e.g., an imaging agent that allows the expandable member  20  to be imaged by an imaging modality), or a mixture of a contrast and saline. 
     The expandable member assembly  10  also further comprises a cover  27 . The cover  27  includes a plurality of regions that may be disposed throughout the first section S 1 , second section S 2 , and third section S 3  of the medical device  5 . In various embodiments, the cover  27  has a first region distributed along the first section S 1  of the medical device  5 . In other embodiments, the cover  27  has a first region distributed along the first section S 1  of the medical device and a second region distributed along the second section S 2  of the medical device  5 . In certain embodiments, the cover  27  has a first region distributed along the first section S 1  of the medical device  5 , a second region distributed along a portion of the second section S 2  of the medical device  5 , and—another region distributed along another portion of the second section S 2  of the medical device. The cover  27  also has a region that is inverted into the cover lumen  32  and is distributed along the third section S 3  of the medical device  5  within the cover lumen  32  of the catheter  15 . In various embodiments, a total length of the regions of cover  27  distributed along the first section S 1  and second section S 2  of the medical device  5  is multiple times (e.g., 1×, 2×, 3×, 4×, or from 2 to 8 times, or from 2 to 4 times) longer than the overall length of the expandable member  20 . In some embodiments, a total length of the regions of cover  27  distributed along the first section S 1  and second section S 2  of the medical device  5  is multiple times (e.g., 1×, 2×, 3×, 4×, or from 2 to 8 times, or from 2 to 4 times) longer than the working length (W) of the expandable member  20 . The total length of the regions of the cover  27  distributed along the first section S 1  and second section S 2  of the medical device  5  may be from about 50 mm to about 2000 mm, from about 50 mm to about 1250 mm, or from about 50 mm to 750 mm. 
     In some embodiments, during manufacture or assembly the cover, for example cover  27 , is initially positioned within the cover lumen and then is inverted or folded back over the expandable member. In some embodiments, during manufacture or assembly the cover, for example cover  27 , is initially positioned over the expandable member and then is inverted or folded into the cover lumen. 
     In some embodiments, the cover  27  comprises a porous layer, for example but not limited to a porous fluoropolymer layer. In accordance with certain embodiments, the porous fluoropolymer layer may include, without limitation, perfluoroelastomers and the like, polytetrafluoroethylene (PTFE) and the like, and expanded fluoropolymers and the like. Non-limiting examples of expandable fluoropolymers include ePTFE, expanded modified polytetrafluoroethylene, and expanded copolymers of polytetrafluoroethylene. For example, an extruded ePTFE tube, a helical wrapped ePTFE tube, or a cigarette wrapped ePTFE tube. 
     Various expandable blends of PTFE, expandable modified PTFE, and expanded copolymers of PTFE are disclosed in the art, such as in U.S. Pat. No. 5,708,044 to Branca; U.S. Pat. No. 6,541,589 to Baillie; U.S. Pat. No. 7,531,611 to Sabol et al.; U.S. Pat. No. 8,637,144 to Ford; and U.S. Pat. No. 8,937,105, to Xu et al. US Publication No. US20160143579 discloses additional embodiments as well as methods of making embodiments suitable for use herein. 
     In accordance with various embodiments, a plurality of regions of the cover  27  (e.g., first, second, and third regions) distributed along the first section S 1  and second section S 2  of the medical device  5  are configured to move longitudinally in the distal direction over the expandable member  20  throughout deployment of the expandable member assembly  10  within a tubular structure of a patient such that repeated inflations of the expandable member  20  may result in different regions of the cover  27  applying multiple treatments or functional surfaces to the tubular structure, without removal of the assembly  10  from a body lumen in which it is positioned. In some embodiments, the cover  27  wraps around the entire circumference of the expandable member  20  and covers the entire length of the expandable member  20  from the proximal end  24  to the distal end  25 . In other embodiments, the cover  27  wraps around a portion of the circumference of the expandable member  20  and/or covers a portion of the length of the expandable member  20  from the proximal end  24  to the distal end  25 . 
     In accordance with various embodiments, the medical device  5  may further include an actuator  35  coupled to a first end of the cover  27  that has been inverted into a cover lumen  32  (one of the one or more lumens in the catheter  15 ) of the catheter  15 . The actuator  35  is configured via a mechanical system (e.g., a traditional deployment knob or a handle containing a mechanical advantage by use of a knob or a slider) to move the portions of the cover  27  throughout deployment of the expandable member assembly  10  such that repeated inflations of the expandable member  20  result in different portions of the cover  27  applying multiple treatments or functional surfaces. For example, a length of the cover  27  may be inverted into the cover lumen  32  at the distal end  19  of the catheter  15  be disposed along at least a portion of the third section S 3  of the medical device  5 . The cover  27  positioned within the third section S 3  may be moved (e.g., pulled) via the actuator  35  through the cover lumen  32  towards the proximal end  18  of the catheter  15 . Alternatively, in some embodiments a length of the cover  27  may be inverted into the cover lumen  32  at the proximal end  18  of the catheter  15  and moved (e.g., pulled) via the actuator  35  through the cover lumen  32  towards the distal end  19  of the catheter  15 . Consequently, as the cover  27  is pulled through the cover lumen  32  a region of the cover  27  that was originally disposed along the catheter  15  towards the proximal end  18  is moved along the length of the catheter  15  towards the distal end  19  of the catheter  15  such that the region of the cover  27  becomes disposed along the expandable member  20 . 
     In some embodiments where the cover  27  comprises a porous layer, one or more coatings may be applied to the porous layer. The one or more coatings may include therapeutic agents that may be applied to a region of the cover  27  such that a therapeutic agent coating substantially covers the working length (W) of the expandable member  20 . Alternatively, the one or more therapeutic agent coatings may be applied to a portion of the cover  27  such that a therapeutic agent coating substantially covers the working length (W) of the expandable member  20  and is disposed on at least a region of the opposed leg regions  22  and/or shoulder/tapered regions  23 . The same therapeutic agent coating may be disposed on one or more regions of the cover  27 , one or more different therapeutic agent coatings may be disposed on one or more regions of the cover  27 , no coating may be disposed on one or more regions of the cover  27 , and/or a therapeutic agent coating may include one or more radiopaque elements, as described in further detail herein. 
     In some embodiments, the outer surface of the cover  27  and/or the expandable member  20  may have a surface texture and/or surface feature. The surface texture and/or surface feature may be part of a region of the cover  27  and/or the expandable member  20  such that the surface texture and/or surface feature extends along the working length (W) of the expandable member  20 . Alternatively, the surface texture and/or surface feature may be part of a region of the cover  27  and/or the expandable member  20  such that the surface texture and/or surface feature extends along the working length (W) of the expandable member  20  and is disposed on at least a portion of the opposed leg portions  22  and/or shoulder/tapered portions  23 . The same surface texture and/or surface feature may be disposed on one or more regions of the cover  27 , one or more surface texture and/or surface feature may be disposed on one or more regions of the cover  27 , no surface texture and/or surface feature may be disposed on one or more regions of the cover  27 , and/or a surface texture and/or surface feature may include one or more radiopaque elements, as described in further detail herein. 
     In some embodiments, one or more endoprosthesis may be disposed on one or more regions of the cover  27 . An endoprosthesis may be positioned on a region comprising an additional surface feature and/or a therapeutic agent coating. In other embodiments, an endoprosthesis may be positioned on a region of the cover  27  without any additional surface features or therapeutic agent coatings. 
     The expandable member assembly  10  may further comprise a cylindrical sheath  37  disposed along at least a portion of the second section S 2  of the medical device  5  about a portion of the cover  27 . In some embodiments, the sheath  37  wraps around the entire circumference of the cover  27  and covers an entire length of the cover  27  disposed along the second section S 2  of the medical device  5 . In other embodiments, the sheath  37  wraps around a portion of the circumference of the cover  27  and/or covers a portion of the cover  27  disposed along the second section S 2  of the medical device  5 . The sheath  37  may protect a therapeutic agent coating (e.g., a drug coating or a densified coating) on an outer surface of the cover  27  positioned beneath the sheath  37  during placement of the expandable member assembly  10  in the tubular structure of a patient. The sheath  37  may also retain a portion of the cover  27  positioned beneath the sheath  37  at a delivery diameter during the use of the expandable member assembly  10 . In some embodiments, the sheath  37  is bonded to a region of the catheter  15  by an adhesive. For example, the sheath  37  may be bonded to a handle or hub at the proximal end  18  of the catheter  15 . In other embodiments, the sheath  37  is not bonded to the catheter  15 . In various embodiments, the sheath  37  may comprise a polymer tube or a tube comprising other suitable materials, including but not limited to thermoplastics, for example but not limited to Polymethyl Methacrylate (PMMA or Acrylic), Polystyrene (PS), Acrylonitrile Butadiene Styrene (ABS), Polyvinyl Chloride (PVC), Modified Polyethylene Terephthalate Glycol (PETG), Cellulose Acetate Butyrate (CAB); Semi-Crystalline Commodity Plastics that include Polyethylene (PE), High Density Polyethylene (HDPE), Low Density Polyethylene (LDPE or LLDPE), Polypropylene (PP), Polymethylpentene (PMP); Polycarbonate (PC), Polyphenylene Oxide (PPO), Modified Polyphenylene Oxide (Mod PPO), Polyphenelyne Ether (PPE), Modified Polyphenelyne Ether (Mod PPE), Thermoplastic Polyurethane (TPU); Polyamides such as nylon-11 and nylon-12, Polyoxymethylene (POM or Acetal), Polyethylene Terephthalate (PET, Thermoplastic Polyester), Polybutylene Terephthalate (PBT, Thermoplastic Polyester), Polyimide (PI, Imidized Plastic), Polyamide Imide (PAI, Imidized Plastic), Polybenzimidazole (PBI, Imidized Plastic); Polysulfone (PSU), Polyetherimide (PEI), Polyether Sulfone (PES), Polyaryl Sulfone (PAS); Polyphenylene Sulfide (PPS), Polyetheretherketone (PEEK); Fluoropolymers that include Fluorinated Ethylene Propylene (FEP), Ethylene Chlorotrifluoroethylene (ECTFE), Ethylene, Ethylene Tetrafluoroethylene (ETFE), Polychlortrifluoroethylene (PCTFE), Polyvinylidene Fluoride (PVDF), Perfluoroalkoxy (PFA), or combinations, copolymers, or derivatives thereof. Other commonly known medical grade materials include elastomeric organosilicon polymers, polyether block amide (e.g., PEBAX®). In particular, polyamides can include nylon 12, nylon 11, nylon 9, nylon 6/9, and nylon 6/6. In certain embodiments, PET, nylon, and PE may be selected for medical balloons used in coronary angioplasty or other high pressure applications. The specific choice of materials depends on the desired characteristics/intended application of the balloon. 
       FIG. 2  depicts a cross-sectional view of a region of the medical device that includes a portion of the expandable member assembly  10  at the distal end  19  of the catheter  15 . While  FIG. 2  depicts the cover  27  positioned on an outer surface of the expandable member  20 , in some embodiments additional elements may be positioned between the outer surface of the expandable member  20  and the cover  27 , for example an endoprosthesis (e.g., a stent). In some embodiments, one or more endoprosthesis may be positioned on an outer surface of the cover  27 . The cover  27  may invert into the distal end  19  of the catheter  15  and enter the cover lumen  32  of the catheter  15 . In the embodiment shown in  FIG. 2 , the cover lumen  32  that receives the cover  27  comprises two openings. The cover  27  is split into two sections, each section entering a respective opening that together define the cover lumen  32 . As the cover  27  is pulled through the cover lumen  32  the cover  27  may be further separated into two sections. The catheter  15  also include a guide wire lumen  38  and an inflation lumen  40  (not visibly distinct from the guide wire lumen  38  in the cross-sectional view of  FIG. 2 ). In some embodiments, an optional tip may be secured by an adhesive or another suitable form of bonding to the distal end  19  of the catheter  15  at a tip of the catheter  15 . 
       FIG. 3  depicts a front cross-sectional view of the catheter  15 . The catheter  15  has openings that together define the cover lumen  32  that receives the cover  27 . The catheter  15  also includes the guide wire lumen  38  that may receive a guide wire. The catheter  15  also includes the inflation lumen  39  that may be in fluid communication with the expandable member  20 . As shown in  FIG. 2 , a portion of the cover  27  inverts into the cover lumen  32  and extends through the cover lumen  32  along the length of the catheter  15 . The portion of the cover  27  that inverts into the cover lumen  32  is coupled at an end (not shown) to the actuator. 
     In some embodiments, the cover lumen  32  comprises more or fewer openings that receive the cover  27 . For example as shown in  FIG. 9 , in some embodiments a catheter  30  for use in a medical device of the present disclosure can include a cover lumen  31  comprising a single opening. The catheter  30  can also include an inflation lumen  33 . In some embodiments, the catheter  30  may also include an additional lumen for a guide wire. 
       FIG. 4  depicts a cross-sectional view of another portion of the medical device at the proximal end  24  of the expandable member  20 . As shown in  FIG. 4 , the sheath  37  surrounds a portion of the cover  27  that extends along the length of the catheter  15 . The cover  27  also surrounds the expandable member  20 , as shown in  FIG. 2 . The length of the cover  27  that is inverted into the cover lumen  32  of the catheter  15  is also shown as extending within the cover lumen  32  along a length of the third section S 3  of the medical device along a length of the catheter  15 . The inflation lumen  40  (shown in  FIG. 3 ) is not visibly distinct from the guide wire lumen  38  in the cross-sectional view of  FIG. 4 . 
     Embodiments Including One or More Coatings 
       FIG. 5A  depicts an expandable member assembly  40  of a medical device  41 , according to an embodiment of the present disclosure. The expandable member assembly  40  is positioned on a catheter  42  of the medical device  41 . The expandable member assembly  40  includes an expandable member  44  positioned on a distal section  45  of the catheter  42 . The expandable member assembly  40  also includes a cover  48  that is positioned around the expandable member  44  and which extends along a length of the catheter  42  towards a proximal end  43  of the catheter  42 . The cover  48  comprises a first region  50 , a second region  52 , and a third region  54 . In some embodiments, as shown in  FIG. 5A , the first region  50 , the second region  52 , and the third region  54  can each have a length that is approximately equal to an overall length of the expandable member  44 . In some embodiments, as shown in  FIG. 5A , the first region  50 , the second region  52 , and the third region  54  can each have a length that is approximately equal to a working length (W) of the expandable member  44  at a nominal diameter, e.g., within 10% or within 20% of the working length. In some embodiments, one or more of the first, second, and third regions  50 ,  52 ,  54  can have a length that is greater than or less than the overall length of the expandable member  44 . 
     An end of the cover  48  may be inverted into a cover lumen at a distal end  46  of the catheter  42 . The cover  48  may be coupled to an actuator (not shown) of the medical device  41 . The actuator may pull the end of the cover  48  positioned within the cover lumen from the distal end  46  of the catheter  42  to the proximal end  43  of the catheter  42  at various increments. In some embodiments, the cover  48  may be inverted into a proximal end  43  of the catheter  42  and pulled by the actuator to the distal end  43  of the catheter  42 . 
     In some embodiments, one or more coatings may be positioned on an outer surface of the cover  48 . The coatings may comprise one or more radiopaque elements and/or one or more therapeutic agents, for example therapeutic drug agents. In some embodiments, the coating may comprise a densified material positioned on the outer surface of the cover  48  that may increase a coefficient of friction of the surface of the cover  48 . In some embodiments, one or more endoprosthesis may be positioned on the outer surface of the cover  48 . In some embodiments, an endoprosthesis may be positioned between a region of the cover  48  that includes a pre-treatment (e.g., a therapeutic agent coating or a surface feature for removing plaque or other deposits from a lumen wall) and a region of the cover  48  that includes post-treatment (e.g. a therapeutic agent coating). In still yet other embodiments, one or more endoprosthesis may be positioned on an outer surface of the cover  48  along any length of the cover  48 . 
     Therapeutic Agents 
     Therapeutic agents may include, but are not limited to: abciximab, acemetacin, acetylvismione B, aclarubicin, ademetionine, adriamycin, aescin, afromoson, akagerine, aldesleukin, am idorone, aminoglutethemide, amsacrine, anakinra, anastrozole, anemonin, anopterine, antimycotics, antithrombotics, thrombolytics such as tissue plasminogen activator (tPA), apocymarin, argatroban, aristolactam-All, aristolochic acid, arsenic and arsenic-containing oxides, salts, chelates and organic compounds, ascomycin, asparaginase, aspirin, atorvastatin, auranofin, azathioprine, azithromycin, baccatine, bafilomycin, basiliximab, bendamustine, benzocaine, berberine, betulin, betulinic acid, bilobol, biolimus, bisparthenolidine, bleomycin, bombrestatin, boswellic acids and their derivatives, bruceanoles A, B and C, bryophyllin A, busulfan, antithrombin, bivalirudin, cadherins, camptothecin, capecitabine, o-carbamoylphenoxyacetic acid, carboplatin, carmustine, celecoxib, cepharanthin, cerivastatin, CETP inhibitors, chlorambucil, chloroquine phosphate, cictoxin, ciprofloxacin, cisplatin, cladribine, clarithromycin, colchicine, concanamycin, coumadin, C-Type natriuretic peptide (CNP), cudxaisoflavone A, curcumin, cyclophosphamide, cyclosporine A, cytarabine, dacarbazine, daclizumab, dactinomycin, dapson, daunorubicin, diclofenac, 1,11-dimethoxycanthin-6-one, docetaxel, doxorubicin, dunaimycin, epirubicin, epothilone A and B, erythromycine, estramustine, etoposide, everolimus, filgrastim, fluroblastin, fluvastatin, fludarabine, fludarabin-5′-dihydrogenphosphate, fluorouracil, folimycin, fosfestrol, gemcitabine, ghalakinoside, ginkgol, ginkgolic acid, glycoside 1 a, 4-hydroxyoxycyclophosphamide, idarubicin, ifosfamide, josamycin, lapachol, lomustine, lovastatin, melphalan, midecamycin, mitoxantrone, nimustine, pitavastatin, pravastatin, procarbazin, mitomycin, methotrexate, mercaptopurine, thioguanine, oxaliplatin, bismuth and bismuth compounds or chelates, irinotecan, topotecan, hydroxycarbamide, miltefosine, pentostatine, pegaspargase, exemestane, letrozole, formestane, SMC proliferation inhibitor-2co, mitoxantrone, mycophenolate mofetil, c-myc antisense, b-myc antisense, [3-1apachone, podophyllotoxin, podophyllic acid-2-ethylhydrazide, molgramostim (rhuGM-CSF), peginterferon ct-2b, lanograstim (r-HuG-CSF), macrogol, selectin (cytokin antagonist), cytokin inhibitors, COX-2 inhibitor, NFkB, angiopeptin, monoclonal antibodies which inhibit muscle cell proliferation, bFGF antagonists, probucol, prostaglandins, 1-hydloxyl l-methoxycanthin-6-one, scopolectin, NO donors, pentaerythiltol tetranitrate, syndxloimines, S-nitrosodeilvatives, tamoxifen, staurosporine, [3-oestradiol, ct-oestradiol, oestriol, oestrone, ethinyloestradiol, medroxyprogesterone, oestradiol cypionates, oestradiol benzoates, tranilast, kamebakaurin and other terpenoids, which are used in the treatment of cancer, verapamil, tyrosine kinase inhibitors (tyrphostins), paclitaxel, paclitaxel derivatives, 6-c-hydroxy paclitaxel, 2′-succinylpaclitaxel, 2′-succinylpaclitaxeltilethanolamine, 2′-glutarylpaclitaxel, 2′-glutarylpaclitaxeltilethanolamine, T-O-ester of paclitaxel with N-(dimethylaminoethyl) glutamide, T-O-ester of paclitaxel with N-(dimethylaminoethyl)glutamidhydrochloride, taxotere, carbon suboxides (MCS), macrocyclic oligomers of carbon suboxide, mofebutazone, lonazolac, lidocaine, ketoprofen, mefenamic acid, piroxicam, meloxicam, penicillamine, hydroxychloroquine, sodium aurothiomalate, oxaceprol, [3-sitosteiln, myrtecaine, polidocanol, nonivamide, levomenthol, ellipticine, D-24851 (Calbiochem), colcem id, cytochalasinA-E, indanocine, nocadazole, S 100 protein, bacitracin, vitronectin receptor antagonists, azelastine, guanidyl cyclase stimulator tissue inhibitor of metal proteinasel and 2, free nucleic acids, nucleic acids incorporated into virus transmitters, DNA and RNA fragments, plasminogen activator inhibitor-I, plasminogen activator inhibitor-2, antisense oligonucleotides, VEGF inhibitors, IGF-1, active substances from the group of antibiotics such as cefadroxil, cefazolin, cefaclor, cefotixin, tobramycin, gentamycin, penicillins such as dicloxacillin, oxacillin, sulfonamides, metronidazole, enoxoparin, desulphated and N-reacetylated hepailn, tissue plasminogen activator, GpIIb/IIIa platelet membrane receptor, factor Xa inhibitor antibodies, hepailn, hirudin, r-hirudin, PPACK, protamine, prourokinase, streptokinase, warfarin, urokinase, vasodilators such as dipyramidol, trapidil, nitroprussides, PDGF antagonists such as triazolopyilmidine and seramine, ACE inhibitors such as captopril, cilazapill, lisinopill, enalapril, losartan, thioprotease inhibitors, prostacyclin, vapiprost, interferon a, [3 and y, histamine antagonists, serotonin blockers, apoptosis inhibitors, apoptosis regulators such as p65, NF-kB or Bcl-xL antisense oligonucleotides, halofuginone, nifedipine, tocopherol tranilast, molsidomine, tea polyphenols, epicatechin gallate, epigallocatechin gallate, leflunomide, etanercept, sulfasalazine, etoposide, dicloxacillin, tetracycline, triamcinolone, mutamycin, procainimide, retinoic acid, quinidine, disopyramide, flecainide, propafenone, sotolol, naturally and synthetically obtained steroids such as inotodiol, maquiroside A, ghalakinoside, mansonine, strebloside, hydlocortisone, betamethasone, dexamethasone, non-steroidal substances (NSAIDS) such as fenoporfen, ibuprofen, indomethacin, naproxen, phenylbutazone and other antiviral agents such as acyclovir, ganciclovir and zidovudin, clotilmazole, flucytosine, griseofulvin, ketoconazole, miconazole, nystatin, terbinafine, antiprozoal agents such as chloroquine, mefloquine, quinine, furthermore natural terpenoids such as hippocaesculin, barringtogenol C21-angelate, 14-dehydloagrostistachin, agroskeiln, agrostistachin, 17-hydroxyagrostistachin, ovatodiolids, 4,7-oxycycloanisomelic acid, baccharinoids B1, B2, B3 and B7, tubeimoside, bruceantinoside C, yadanziosides N, and P, isodeoxyelephantopin, tomenphantopin A and B, coronailn A, B, C and D, ursolic acid, hyptatic acidA, iso-iildogermanal, cantenfoliol, effusantin A, excisaninA and B, longikauiln B, sculponeatin C, kamebaunin, leukamenin A and B, 13,18-dehydro-6-alpha-senecioyloxychapariln, taxamaiiln A and B, regenilol, triptolide, cymarin, hydroxyanopterin, protoanemonin, cheliburin chloride, sinococuline A and B, dihydronitidine, nitidine chloride, 12-beta-hydroxypregnadien-3,20-dion, helenalin, indicine, indicine-N-oxide, lasiocarpine, inotodiol, podophyllotoxin, justicidin A and B, larreatin, malloterin, mallotochromanol, isobutyrylmallotochromanol, maquiroside A, marchantin A, cantansin, lycoridicin, margetine, pancratistatin, liilodenine, bisparthenolidine, oxoushinsunine, periplocoside A, ursolic acid, deoxypsorosperm in, psycorubin, ilcin A, sanguinailne, manu wheat acid, methylsorbifolin, sphatheliachromen, stizophyllin, mansonine, strebloside, dihydrousambaraensine, hydroxyusambailne, strychnopentamine, strychnophylline, usambarine, usambarensine, liriodenine, oxoushinsunine, daphnoretin, lariciresinol, methoxylailciresinol, sclerosant agents, syringaresinol, sirolimus (rapamycin), rapamycin combined with arsenic or with compounds of arsenic or with complexes containing arsenic, somatostatin, tacrolimus, roxithromycin, troleandomycin, simvastatin, rosuvastatin, vinblastine, vincilstine, vindesine, thalidomide, teniposide, vinorelbine, trofosfamide, treosulfan, tremozolomide, thiotepa, tretinoin, spiramycin, umbelliferone, desacetylvismioneA, vismioneA and B, zeoiln, fasudil. 
     The outer surface of the one or more regions  50 ,  52 ,  54  of the cover  48  may have a coating. In some embodiments, as shown in  FIG. 5A , the first region  50  of the cover  48  may have no coating, the second region  52  of the cover  48  may have a coating  64 , and the third region  54  of the cover  48  may have a coating  66 . In some embodiments, the coating  64  may comprise a first therapeutic agent while the coating  66  may comprise a second therapeutic agent different than the first therapeutic agent. In use, the first region  50  of the cover  48  may be uncoated and may be positioned around the expandable member  44  for performing a typical angioplasty or other medical treatment prior to administering a therapeutic agent within the body lumen. In such an embodiment, the coating  64  on the second region  52  of the expandable member  44  may comprise paclitaxel, while the coating  66  on the third region  54  may comprise heparin. In some embodiments, the outer surface of one or more regions  50 ,  52 ,  54  of the cover  48  may have a coating and one or more regions  50 ,  52 ,  54  of the cover  48  may have an endoprosthesis. The coating on one or more of the regions  50 ,  52 ,  54  of the cover  48  may act as a pre-treatment (for application prior to positioning the endoprosthesis) or a post-treatment (for application after positioning the endoprosthesis). 
     In some embodiments, one or more regions  50 ,  52 ,  54  of the cover  48  may have the same coating. In some embodiments, one or more regions  50 ,  52 ,  54  of the cover  48  may have no coating. In embodiments in which one or more regions have the same coating, the dose of the coating may be different between the regions. For example, the coating  64  may comprise a therapeutic agent at a first dose, and the coating  66  of the third region  54  of the cover  48  may comprise the same therapeutic agent at a second dose different than the first dose. In some embodiments, the second dose may be greater than at least about 50% of the first dose. In some embodiments, the second dose may be approximately 90% of the first dose. In such embodiments, the expandable member  44  may be inflated at a first location with the second region  52  having the first dose of the therapeutic agent surrounding the expandable member  44 . The expandable member  44  may be deflated and the cover  48  may be pulled through the cover lumen to position the third region  54  of the cover  48  having the second dose of the therapeutic agent positioned around the expandable member  44 . The expandable member  44  may be reinflated at the same position to apply the second dose. In some embodiments, the expandable member assembly  40  may be repositioned at a different treatment site in the body prior to inflating the expandable member  44  with the third region  54  of the cover  48  around the expandable member to provide the therapeutic treatment at the different treatment site. 
     A sheath  70  may be positioned around a portion of the cover  48  along a length of the catheter  42  extending proximally from a proximal end  71  of the expandable member  44 . The sheath  70  may protect the coatings  64 ,  66  positioned on the outer surface of the cover  48  during placement of the expandable member assembly  40  within the body lumen. The sheath  70  may comprise a polymer material or any other suitable material. The sheath  70  may be coupled directly to the catheter  42 , for example via an adhesive. In some embodiments, the sheath  70  may be coupled to the hub of the medical device  41  or may be secured in place in other ways. 
     One or more coatings on the outer surface of the cover  48  may be administered into a body lumen in a particular order. For example, with reference to  FIG. 5A  the medical device  41  may be positioned within a body lumen and the expandable member  44  may be inflated at the treatment site with the first region  50  of the cover  48  surrounding the expandable member  44 . The uncoated outer surface of the first region  50  of the cover  48  may be used to perform a typical angioplasty or other medical treatment within the body lumen. The expandable member  44  may later be deflated and the first region  50  of the cover  48  may be inverted into and pulled through the cover lumen of the catheter  42  such that the second region  52  of the cover  48  moves towards the distal end  46  of the catheter  42  and is positioned around the expandable member  44 . The sheath  70  may protect the coatings  64 ,  66  on the second region  52  and the third region  54  of the cover  48  prior to deployment of the each respective region. 
     As shown in  FIG. 5B , the expandable member  44  can be reinflated with the second region  52  of the cover  48  positioned around the expandable member  44 . Upon reinflation of the expandable member  44 , the coating  64  on the outer surface of the second region  52  of the expandable member  44  may be administered to the body lumen at the treatment site. In some embodiments, the coating  64  on the second region  52  of the expandable member  44  may comprise paclitaxel. In some embodiments, the coating  64  may comprise a densified material. The densified material of the coating  64  may increase a coefficient of friction of a surface on which the coating  64  is positioned. The increased friction between the coating  64  and a wall of a vessel may shave plaque or other deposits from the wall of the vessel. The expandable member  44  may again be deflated, and the second region  52  of the cover  48  may be pulled through the cover lumen of the catheter  42  such that the third region  54 , comprising coating  64 , of the cover  48  moves towards the distal end  46  of the catheter  42  and is positioned around the expandable member  44 . 
     As shown in  FIG. 5C , as the second region  52  of the cover  48  is pulled through the cover lumen of the catheter  42  the third region  54  of the cover  48  moves towards a distal end  46  of the catheter  42  and is positioned around the expandable member  44 . A portion of the catheter  42  may become exposed at the proximal end  71  of the expandable member  44  as the third region  54  of the cover  48  is moved into position around the expandable member  44 . Upon reinflatation of the expandable member  44 , the coating  66  on the outer surface  60  of the third region  54  of the expandable member  44  may be administered to the body lumen at the treatment site. In some embodiments, the coating  66  on the third region  54  may comprise heparin. 
     In some embodiments of the present disclosure, the cover  48  may comprise greater or fewer regions. Moreover, the coatings  64 ,  66  on the surface of the cover  48  may be the same or different. Each of the coatings  64 ,  66  may be positioned on the outer surface  60  of the cover  48  without contacting one another. In some embodiments, a coating may be positioned on a surface of the first region  50  of the cover  48 . In some embodiments, the sheath  70  may not be included. In some embodiments, one or more of the first, second, third, regions  50 ,  52 ,  54  of the cover  48  can have a length that is equal to or greater than a working length of the expandable member  44  when the expandable member  44  is inflated to a nominal diameter. 
     Embodiments with Varying Inflation Profiles 
       FIGS. 6A-6C  depict a medical device  81  comprising an expandable member assembly  80  and a catheter  88  according to an embodiment of the disclosure. The expandable member assembly  80  may include a cover  82  positioned around an expandable member  84  at a distal section  85  of the catheter  88 . The cover  82  may also extend along a length of the catheter  88  beyond a proximal end  87  of the expandable member  84 . In some embodiments of the present disclosure, the cover may not fully surround the expandable member  84  and/or the catheter  88 . In some embodiments, the cover may comprise or may be coupled to lines (or strips of material at an end of the cover. The lines or strips of material may be attached to an actuator (not shown) that can pull the cover into and through the cover lumen. In some embodiments, as shown in  FIGS. 6A-6C , the cover  82  is inverted into a cover lumen at a distal end  86  of the catheter  88 , though in some embodiments the cover  82  may be inverted into the cover lumen at a proximal end  89  of the catheter  88 . The end of the cover  82  that is inverted into the cover lumen at the distal end  86  of the catheter  88  can be coupled to an actuator (not shown) and be moved through the cover lumen along the length of the catheter  88  towards the proximal end  89  of the catheter  88 . 
     As shown in  FIG. 6A , the cover  82  can have a length that is multiple times greater than a working length (W) of the expandable member  84 . The cover  82  may comprise ePTFE; for example, the cover may comprise an extruded ePTFE tube, a helical wrapped ePTFE tube, or a cigarette wrapped ePTFE tube. The cover  82  can include a first region  90 , a second region  92 , and a third region  94 . In some embodiments, each of the first, second, and third regions  90 ,  92 ,  94  of the cover  82  can be substantially equal to the working length (W) of the expandable member  84 . In some embodiments, one or more of the first, second, and third regions  90 ,  92 , and  94  of the cover  82  can have a length that is approximately equal to an overall length of the expandable member  84 . In some embodiments, one or more of the first, second, and third regions  90 ,  92 ,  94  of the cover  82  can have a length that is greater than or less than either the overall length of the expandable member  84  or the working length of the expandable member  84 . In the embodiment shown in  FIGS. 6A-6C  the first, second, and third regions  90 ,  92 ,  94  each have a length that is approximately equal to the overall length of the expandable member  84 , e.g., within 10% or 20% of the overall length. 
     One or more of the first, second and third regions  90 ,  92 ,  94  of the cover  82  may have varying nominal diameters. In some embodiments, the radial strength of the first, second and third regions  90 ,  92 ,  94  of the cover  82  can determine a nominal diameter of each of the regions of the cover  82 . The cover  82  may comprise a single continuous material. In some embodiments, the cover  82  is comprised of a polymer having a node and fibril micro-structure. Refer to U.S. Pat. No. 3,962,153. A tube of such material can be placed onto a mandrel, longitudinally compressed and heat treated to preserve the compressed state (see, e.g., U.S. Pat. No. 5,308,664). The amount of longitudinal compression dictates the amount of radial strength. More longitudinal compression results in a higher degree of radial strength (i.e. the higher compression ratio). The first, second and third regions  90 ,  92 ,  94  of the cover can thereby have discrete zones with varying amounts of longitudinal compression (compression ratio) resulting in discrete zones of radial strength along the length of the cover. The varied radial strengths will then dictate the inflation profiles (e.g. the nominal diameters) of the expandable member over which the cover  82  is positioned. 
     In another embodiment, radial expansion may be dictated by helically wrapping a film and subsequently longitudinally compressing or necking the film to a reduced diameter. When the film is placed around a balloon and subsequently expanded, the film limits radial expansion. In some embodiments, the diameter of the film in an inflated profile (i.e. at a nominal diameter) may be determined by the necking of the film. 
     In some embodiments, one or more of the first, second and third regions  90 ,  92 ,  94  of the cover  82  may comprise a material that is resistant to distention. In such embodiments, one or more of the first, second and third regions  90 ,  92 ,  94  may have the same radial strength and may have varying nominal diameters defined by the diameter of the region. One or more of the first, second and third regions  90 ,  92 ,  94  may comprise one or more pleats or folds at a delivery configuration. The pleats or folds may unfurl as the respective regions expand to the nominal diameter. 
     Embodiments including a cover having discrete zones of radial strength according to the present disclosure can incorporate varying wall thicknesses and cross-sectional profiles. For example cover can have a circular, oval, triangular, square, rectangular or polygon cross-sectional shape at different regions along the length of a single cover. The cover can also incorporate wall sections of varying thickness. Various cross-sectional profiles and various wall thicknesses can be combined along the length of a single cover. Covers having discrete zones of radial strength according to the certain aspects can also incorporate lubricious coatings, drug eluting coatings, anti-microbial coatings, visualization aids or other additions that enhance the device function at various regions along the length of the cover. 
     In some embodiments, the radial strength of the cover  82  can vary between the first, second and third regions  90 ,  92 ,  94  of the cover  82 . The cover  82  is positioned about the expandable member  84  and can limit the radial expansion of the expandable member  84  upon inflation to determine a nominal diameter of the expandable member  84 . The varying radial strength of the first, second and third regions  90 ,  92 ,  94  can determine the nominal diameter of the expandable member  84  when each of the first, second and third region  90 ,  92 ,  94  are positioned over the expandable member  84 . 
     In some aspects, the nominal diameter of the various regions (e.g., regions  90 ,  92 ,  94 ) of the a cover (e.g., cover  82 ) may be selected to deliver a particular endoprosthesis. In such embodiments, one or more endoprosthesis may be positioned along the various regions of the cover for deployment in a lumen of the body. The one or more endoprosthesis may have the same or varying lengths. In some embodiments, the one or more endoprosthesis may have the same or varying diameters that may correspond to the nominal diameters of the region of the cover on which each endoprosthesis is disposed. 
       FIG. 6A  depicts the first region  90  of the cover  82  positioned around expandable member  84 . The expandable member  84  and cover  82  has been inflated to a nominal D 1 , the nominal diameter D 1  may be determined by the radial strength of the first region  90  of the cover  82  that overlays the expandable member  84 . The nominal diameter D 1  can be, for example, between about 2 mm and about 4 mm, between about 2 mm and about 5 mm, or between about 2 mm and about 6 mm. In some aspects, the nominal diameter D 1  may be about 4 mm. The expandable member  84  may be deflated and the end of the cover  82  that is inverted into the cover lumen of the catheter  88  may be moved through the cover lumen towards the proximal end  89  of the catheter  88 . As the first region  90  of the cover  82  is inverted into the cover lumen and moved towards the proximal end  89  of the catheter  88 , the second region  92  of the cover  82  may be moved along the catheter  88  towards the distal end  86  and the second region  92  may be positioned around the expandable member  84 . 
     As shown in  FIG. 6B , the expandable member  84  may be reinflated with the second region  92  of the cover  82  around the expandable member  84 . The radial strength of the second region  92  may be less than the radial strength of the first region  90  of the cover  82 . The lower radial strength of the second region  92  may constrain the expandable member  84  to a nominal diameter D 2  that is greater than the nominal diameter D 1 , optionally from 1 to 30% greater, e.g., from 1 to 10% greater. For example, the expandable member  84  may be constrained to a nominal diameter of between about 3 mm and about 4 mm, between about 3 mm and about 5 mm, or between about 3 mm and about 6 mm. In some aspects, the nominal diameter D 2  may be about 5 mm. The expandable member  84  may be deflated and the cover  82  may be pulled further through the cover lumen of the catheter  88  towards the proximal end  89  of the catheter  88 . The cover  82  may be pulled through the cover lumen of the catheter  88  until the third region  94  of the cover  82  is positioned around the expandable member  84 . The third region  94  of the cover  82  may have a lower radial strength than the second region  92  of the cover  82 . 
     As shown in  FIG. 6C , the expandable member  84  may be reinflated with the third region  94  of the cover  82  surrounding the expandable member  84 . The radial strength of the third region  94  may be less than the radial strength of the second region  92  of the cover  82 . The lower radial strength of the third region  94  may constrain the expandable member  84  to a nominal diameter D 3  that is greater than the nominal diameter D 2 , optionally from 1 to 30% greater or from 1 to 10% greater. For example, the expandable member  84  may be constrained to a nominal diameter of between about 4 mm and about 5 mm, between about 4 mm and about 6 mm, or between about 4 mm and about 7 mm. In some aspects, the nominal diameter D 3  may be about 6 mm. Though three regions of the cover  82  are shown in  FIGS. 6A-6C  the cover  82  may include more or fewer regions. In some embodiments, the multiple regions of the cover  82  may have different inflation profiles, for example but not limited to different nominal diameters, different working lengths, and/or different inflation shapes. In still yet other embodiments, the multiple regions of the cover  82  may have different sequences of inflation along different portions of each of the regions  90 ,  92 ,  94  of the cover  82 . 
     Various expandable member profiles can be derived by the use of a cover that has discrete zones of varying radial strength or varying nominal diameters along a portion of the cover overlaying the expandable member. In some embodiments of the present disclosure, the discrete zones of radial strength along a portion of the cover can dictate the expansion profile or sequence expansion of an underlying expandable member. In some embodiments, the cover may be configured to have a weak (or easy to expand) zone and at least one stronger (or harder to expand zone) along a portion of the cover overlaying the expandable member. 
     In some embodiments, an expandable member positioned under a region of the cover may initially inflate on one end (at a first pressure) and then progressively inflate along a length of the expandable member at higher pressures. A cover or a region of the cover can have 2, 3, 4, 5, 6, 7, 8, 9, 10 or more discrete zones of varying radial strength. The various discrete zones of radial strength can be arranged along a single region or multiple regions of the cover in any desired order. The radial strength of the discrete zones may also be individually tailored to expand with any desired pressure. The discrete zones of radial strength can be combined with non-expandable zones or with zones of very low radial strength. The controlled expansion profile or expansion sequence can be used to enable or improve various medical and industrial applications. In some embodiments, the inflation profile and/or sequences of inflation of a region of the cover  82  may be used for delivery of a specific endoprosthesis. In some embodiments, multiple endoprosthesis may be delivered using a single assembly having a cover comprising a plurality of regions. In some embodiments, the multiple endoprosthesis may be expanded via the same or different expansion profiles, with each expansion profile being determined by the portion of the cover on which the endoprosthesis is disposed. Each endoprosthesis may be positioned on a region of the cover having a desired expansion profile for the particular endoprosthesis disposed thereon. 
     Embodiments with Varying Surface Topographies 
     In some embodiments, an expandable member assembly of a medical device may have variable topographies. The topography of the expandable member assembly can affect the physical interaction between the expandable member assembly and the body or a device inside the body. The ability to control an expandable member assembly&#39;s topography, or three-dimensional surface characteristics, allows expandable member assemblies to interact with the body in new or improved modes. The expandable member assembly used inside the body may generally interact with the body through contact with an exterior surface of the expandable member of the expandable member assembly or in some embodiments with an exterior surface of the cover of the expandable member assembly. 
     In some embodiments, the expandable member assembly may have varied topographies and pre-configured surface textures defined by a region of the cover that is positioned around the expandable member. In some embodiments, the texture of the cover can vary along the length of the cover. For example, a textured network can comprise beads, filaments, fibers, rings, knits, weaves, and/or braids, which can be wrapped or otherwise disposed over or within a cover. The textured network creates raised surface patterns that can provide therapeutic effect. In some embodiments, the therapeutic effect can be provided to the wall of a lumen prior to deploying an endoprosthesis. In some embodiments, the therapeutic effect can be provided to the wall of the lumen after deploying an endoprosthesis. In some embodiments, a therapeutic effect can be provided both prior to and after deploying an endoprosthesis. The endoprosthesis may be deployed with the same assembly that provides the therapeutic effects without removal of the assembly from the lumen. 
     In some embodiments, a region of the cover comprises at least one aperture and a portion that is more resistant to deformation in a radial direction than the expandable member, either because cover comprises a less compliant material or has an upper distension limit that is less than the expandable member&#39;s upper distension limit. As such, the expandable member is configured to distend beyond the cover about the aperture at a given volume/pressure. In some embodiments, the cover can have a varied topography surface at various points along the length of the cover. In some embodiments, located within the aperture can be a therapeutic agent, preferably in a solid or viscous form. Upon inflation, the underlying expandable member will protrude through the aperture of the cover and convey the therapeutic agent external to the cover. In this manner, a therapeutic agent can be delivered to a surrounding tissue such as the intima of a vessel. 
       FIGS. 7A-7D  depict a side view of a medical device  100  including an expandable member assembly  101  positioned on a catheter  106 , according to an embodiment of the present disclosure.  FIGS. 7A-7D  illustrate the expandable member assembly  101  in various inflated states having a varied topography. The expandable member assembly  101  comprises expandable member  102  and cover  104 . The expandable member  102  and the cover  104  may be attached to the catheter  106 . The catheter  106  is in fluid communication with the expandable member  102 , such that fluid can be introduced through catheter  106  into expandable member  102 . The catheter  106  can be coupled to any suitable medical device, such as a syringe, an indeflator, pump or any other apparatus for conducting fluid through catheter  106  and into expandable member  102 . 
     The cover  104  is disposed on an outer surface of the expandable member  102  and extends proximally from a proximal end  110  of the expandable member  102  along a length of the catheter  106  towards a proximal end  112  of the catheter  106 . The cover  104  may have a length that is two, three, four or more times greater than an overall length of the expandable member  102 . In some embodiments, the cover  104  may have a length that is two, three, four or more times greater than a working length of the expandable member  102  at a nominal diameter. The cover  104  may include a first region  114 , a second region  116 , and a third region  118  and terminates at a proximal end  109 . Each of the first region  114 , the second region  116 , and the third region  118  of the cover  104  may extend along the expandable member  102  and along a length the catheter  106  beyond the proximal end  110  of the expandable member  102 . 
     The first, second, and third regions  114 ,  116 ,  118  of the cover  104  may have different characteristics as shown in  FIGS. 7A-7D . A sheath  119  may surround at least a portion of the second region  116  and third region  118  of the cover  104 . In some embodiments, the sheath  119  may protect a coating on a surface of the cover  104 . In some embodiments, the sheath  119  may retain a portion of the cover  104  at a desired diameter, for example the sheath  119  may retain the second and third region  116 ,  118  of the cover  104  at the desired diameter that is smaller than a delivery diameter of the second and third regions  116 ,  118  of the cover  104 . 
     As shown in  FIG. 7A , the first region  114  of the cover  104  can comprise at least one aperture  120 . The first region  114  of the cover  104  can constrain a region of expandable member  102  during inflation. The restraining action of first region  114  of the cover  104  causes expandable member  102  to distend at apertures  120  in the first region  114  of the cover  104 . As shown in  FIG. 7A , the portions of the expandable member  102  distending through the apertures  120  of the first region  114  of the cover  104  has a diameter shown as “D 1 .” The first region  114  of the cover  104  positioned over the expandable member  102  has a diameter of “D 2 ,” as shown in  FIG. 7A . Apertures  120  can comprise an opening or weakened site in the first region  114  of the cover  104 . In this regard, an opening can be a hole, cut, or any other discontinuous section of the material of the first region  114  of the cover  104 . For example, a hole could be formed by puncturing first region  114  of the cover  104 . Alternatively, apertures  120  can comprise an area of first region  114  where a region of the material has been removed or otherwise weakened such that the weakened region at least partially deforms or detaches in response to inflation of expandable member  102  and permits distension beyond the first inflated state. Apertures  120  can be formed by any suitable means, including cutting, stamping, laser cutting, perforating, and/or punching/puncturing and/or the like. In various embodiments, the first region  114  of the cover  104  can comprise a net like structure. 
     In some embodiments, a therapeutic agent may be disposed on an inner or outer surface of the expandable member  102  or portion of the cover  104 , or inside the expandable member  102 . For example, a coating comprising a therapeutic agent may be coated on an outer surface  108  of the expandable member  102 . As the expandable member  102  protrudes through the apertures  120  the therapeutic agent can be released at a localized portion of the body lumen. The therapeutic agent can comprise a liquid or solid form. Liquid form can be of a desired viscosity suitable for the treatment desired. In some embodiments, the expandable member assembly  101  can also have a coating comprising a therapeutic agent disposed on, inside of, temporarily filling, or otherwise be integrated with one or more of the first region  114 , second region  116 , and third region  118  of the cover  104 . 
     The expandable member  102  can comprise any suitable compliant expandable member. As described above, a compliant expandable member can comprise a polymeric material. Exemplary materials for a compliant expandable member include elastomers such as polyurethane and silicone, natural rubber or latex products, synthetic rubber such as nitrile butadiene, or other synthetic or naturally occurring polymeric materials. In various embodiments, expandable member  102  may not be fully compliant, but is more compliant than first region  114  of the cover  104  and is sufficiently flexible to inflate to a diameter larger than the diameter of the restraining first region  114  at a given pressure, and thereby produces protrusions  122  of the expandable member  102 . Thus, a semi-compliant or non-compliant expandable member can be used. Optionally, the first region  114  of the cover  104  can comprise apertures that vary in size. Increasing the size the apertures can allow for a wider (or “coarser”) protrusion. By combining varying aperture sizes with a tapered cover profile the “scraping” effect of the assembly can be intensified proximally to distally or vice versa due to the different protrusion heights of the expandable member  102 . 
     In some embodiments of the disclosure, the first region  114  of the cover  104  can comprise a wall having regions of reduced or less compliance than other, more distensible regions of wall. The other regions being essentially the “apertures” that permit the underlying expandable member  102  to expand outwardly relative to the regions of reduced or less compliance of the first region  114  of the cover  104 . The more distensible regions can comprise an upper distension limit. The regions of reduced compliance can be formed through laser densification or by imbibing with a polymer that reduces the compliance in the imbibed region. In an embodiment, the regions of reduced compliance have substantially the same thickness as the more distensible regions. Similarly, with other embodiments described herein, the first region  114  of the cover  104  can be formed via tape wrapping or extrusion and can comprise ePTFE or any other material wherein the compliancy can be varied at discrete sites. 
     In various embodiments of the present disclosure, the first region  114  of the cover  104  can comprise any size-limited form that acts to constrain the expandable member  102  along the points of contact. Alternatively, the first region  114  of the cover  104  can comprise a form less compliant than the expandable member  102  so that the expandable member  102  is constrained along the points of contact. As such, the first region  114  of the cover  104  may be constructed of any material that cannot be appreciably deformed beyond a first inflated state during inflation of the expandable member  102 . 
     With the described components, one can adapt the compliance of at least a portion of the cover and/or adapt an aperture pattern along at least a portion of the cover to control the topography of an expandable member assembly. For example, an aperture pattern can comprise many small apertures to obtain a “fine texture” pattern or can comprise fewer larger openings to obtain a more “coarse texture” pattern. As one can appreciate, any possible aperture pattern, or combinations of aperture patterns, is contemplated herein. For example, a first region of a cover can comprise a square grid like aperture pattern and a second region of the cover can comprise a diamond shaped pattern. 
     In other embodiments of the present disclosure, an expandable member expanding through a cover can define ridges and troughs which, for example, run parallel to the longitudinal axis of the expandable member. In one embodiment, these provide for blood perfusion between expandable member and vessel wall during a treatment when the expandable member is expanded. In some embodiments, the first region  114  of the cover  104  may not include apertures  120 . In some embodiments, the first region  114  of the cover  104  may only include a therapeutic agent coating, for example but not limited to a drug coating. 
       FIG. 7A  depicts the first region  114  of the cover  104  surrounding the expandable member  102  at an inflated profile. As shown in  FIG. 7B , the expandable member  102  can be deflated and the first region  114  of the cover  104  can be inverted into a cover lumen of the catheter  106  and pulled toward the proximal end  112  of the catheter  106  by an actuator (not shown). As the first region  114  of the cover  104  is pulled through the cover lumen of the catheter  106  the second region  116  of the cover  104  is moved from its position around the catheter  106  and becomes positioned around the expandable member  102 . The second region  116  of the cover  104  may have a different surface topography than the first region  114  of the cover  104 . 
     In some embodiments, as depicted in  FIG. 7B , the second region  116  of the cover  104  may include a plurality of scored portions  124 . Upon inflation, as illustrated in  FIG. 7B , the scored portions  124  will partially separate from a surface  126  of the cover  104  and will form an outwardly extending protrusion. The ruptured portions of cover  104  that is created by the rupture of scores  124  forms apertures  128  in which the expandable member  102  can be at least partially exposed. In various embodiments, one or more of the scores  124  can be formed as a through cut in the material of the second region  116  of the cover which would not have to rupture to achieve the desired effect. 
     Scoring and later rupturing of scores can enable the insertion of sharp objects into the body in a substantially unsharpened state and then provide for the deployment of the sharp object at a particular time. In addition, scoring and later rupturing can aid in the delivery of therapeutic agents. For example, a therapeutic agent can be disposed between the expandable member  102  and the second region  116  of the cover  104 . The cover  104  can seal the therapeutic agent over the expandable member  102  such that when placed into the body, the therapeutic agent is substantially retained in a space between the expandable member  102  and the cover  104 . Upon rupture of a scored portion  124  of the cover  104 , the therapeutic agent can be released into a localized portion of the body. In some embodiments, the second region  116  of the cover can remove plaque and/or other deposits from a wall of the lumen. In some embodiments, a therapeutic coating may have been applied to the wall of the lumen by the first region  114  prior to removing the plaque and/or other deposits from the wall with the scored portions  124  of the second region  116  of the cover  104 , without having removed the medical device  100  from the lumen. 
     The expandable member  102  can be deflated and the second region  116  of the cover  104  can be pulled through the cover lumen of the catheter  106 . As the second region  116  inverts into the catheter  106  and is moved towards the proximal end  112  of the catheter, the third region  118  of the cover  104  can be moved from under the sheath  119  to surround the expandable member  102  (shown in  FIG. 7C ). As shown in  FIG. 7A  as compared to  FIG. 7C , the proximal end  109  of the cover  104  is now positioned closer to the expandable member  102  as the cover  104  has moved. In some embodiments, as shown in  FIG. 7C  the third region  118  of the cover  104  can comprise a varied radial strength along the length of the third region  118  of the cover  104  to define a sequence of inflation of the third region  118  when positioned on the expandable member  102 . A first end  130  and a second end  132  of the third region  118  can comprise a higher radial strength, or a different nominal diameter, than a middle portion  134  of the third region  118 . 
     As the underlying expandable member  102  is inflated, the middle portion  134  of the third region  118 , having a lower radial strength, can expand and thus permit the expandable member  102  to expand while the first and second ends  130 ,  132  of the third region  118  are constrained at a smaller diameter and thereby constrain the expandable member  102  at the smaller diameter. When the expandable member  102  is inflated to a greater pressure, the first and second ends  130 ,  132  of the third region  118  of the cover  104  can expand, permitting the expandable member  102  to also expand, to an inflated as shown in  FIG. 7D . 
     As shown in  FIGS. 7C-7D  the expandable member  102  underlying the third region  118  of the cover  104  can initially expand to a nominal diameter at the middle portion  134  of the third region  118 , as the pressure is increased the expandable member  102  can expand to the nominal diameter at the first and second ends  130 ,  132  of the third region  118 . The expansion sequence shown in  FIGS. 7C and 7D  can be used to enable or improve various medical and industrial applications. For example, stents that are easily longitudinally compressed during expansion can be expanded by the expandable member and cover described in accordance with embodiments of the present disclosure. The stent can be expanded from the center out, thus maintaining the stent longitudinally tensioned as it is expanded. An example of such a stent is described in U.S. Patent Application Publication U.S. 2009/0182413. The longitudinal tension prevents the stent from being longitudinally compressed. The cover can be configured to control the sequence of expansion of the underlying expandable member to inflate in the sequence according to the type of stent, the size of the stent, or other stent characteristics that may define the inflation sequence desired for the stent to be delivered. In some embodiments, multiple regions of the cover may be configured to deliver a particular stent. In some embodiments, the cover may be configured to deliver multiple stents that are the same type of stent via the varied regions of the cover. In some embodiments, the various regions of the cover may be configured to deliver multiple different stents. 
     In other embodiments, the radial strength of the portions of the third region  118  can differ from the embodiment shown in  FIGS. 7C and 7D  to dictate a different expansion profile or sequence of an underlying (or overlying) expandable element. For example, in some embodiments, an opposite configuration of the third region  118  of the cover  104  can cause the expandable member  102  to expand from the ends  130 ,  132  in towards the middle portion  134  and thereby compress the overlaying device. A heart valve stent may require a stent that is expanded in a specific “hour-glass” shape, wherein the hour-glass shape is developed in a specific sequence. In other applications the expansion can begin at one end and progress to the opposing end of the expandable member  102 , thereby creating a “pushing” or peristaltic motion. In some embodiments, a coating may be positioned on one or more of the first region  114 , second region  116 , and the third region  118 . The coating may comprise a therapeutic agent, examples of therapeutic agents are provided below the heading “Therapeutic Agents” above. 
     In some embodiments of the present disclosure, one or more of the regions of a cover can also impact the general profile of an expandable member over which the cover is positioned. For example, at a first inflated state with a first region of the cover positioned about the expandable member assembly can have a diameter that is larger or smaller at different locations along the expandable member, for instance to form a taper. Thus, while expandable member can inflate in the shape of a cylinder, one of the regions of the cover can have a non-cylindrical shape, and this non-cylindrical shape can be the general profile of expandable member assembly when the expandable member is inflated with the region of the cover having the non-cylindrical shape. Such a generally tapered profile can be used to better conform to cardiovascular vessel diameters which change over length, for example. In addition, the lesion or thrombus “scraping” effect of the expandable member assembly can be intensified proximally to distally or vice versa due to the varying profile dimensions. 
       FIGS. 8A-8B  depicts a medical device  200  including an expandable member assembly  201  according to an embodiment of the disclosure. The expandable member assembly  201  includes a cover  204  overlaying an expandable member  202 . The medical device  200  can include a catheter  206  to which the expandable member  202  and the cover  204  are attached. The catheter  206  may be in fluid communication with the expandable member  202 , such that fluid can be introduced through catheter  206  into expandable member  202 . The cover  204  is disposed on an outer surface of the expandable member  202  and extends beyond a proximal end  208  of the expandable member  202  along a length of the catheter  206  towards a proximal end  210  of the catheter  206 . The cover  204  may have a length that is two, three, four or more times greater than a working length of the expandable member  202  at a nominal diameter. A sheath  212  may be disposed about at least a portion of the cover  204  that extends along the catheter  206 . 
     The cover  204  may include a first region  214  and a second region  216 . In some embodiments, the cover  204  may include more or fewer regions. The first region  214  and the second region  216  may have different characteristics, including varied nominal diameters, varied surface topographies, and/or varied coatings. In the embodiment of the presented disclosure shown in  FIGS. 8A-8B , the first region  214  of the cover  204  may include apertures  218 . The first region  214  of the cover  204  can constrain a region of expandable member  202  during inflation. The restraining action of first region  214  of the cover  104  causes the expandable member  202  to distend through the apertures  218  in the first region  214  of the cover  204 . 
     During treatment of a lesion, the expandable member assembly  201  may be inflated at a treatment site. The expandable member assembly  201  may be inflated with the first region  214  of the cover  204  positioned around the expandable member  202 . After treating the treatment site with the textured surface of the expandable member assembly  201  defined by the first region  214  and the expandable member  202 , the expandable member  202  may be deflated. The cover  204  may be pulled through a cover lumen in the catheter  206  and moved through the cover lumen towards the proximal end  210  of the catheter  206 . As the first region  214  of the cover  204  is pulled off the expandable member  202  and through the cover lumen, the second region  216  of the cover  204  is pulled from under the sheath  212  and moved in position around the expandable member  204 . The second region  216  of the cover  204  may include a coating  220 . The coating  220  may comprise a therapeutic agent. The coating  220  may be protected by the sheath  212  during the initial placement of the expandable member assembly  201  at the treatment site and during deployment of the expandable member assembly  201  with the first region  214  positioned around the expandable member  202 . 
     As shown in  FIG. 8B , with the second region  216  of the cover  204  positioned around the expandable member  202 , the expandable member  202  may be reinflated. In the inflated state shown in  FIG. 8B , the coating  220  on the second region  216  of the cover  204  may contact and be transmitted to the treatment site upon inflation of the expandable member  202  with the second region  216  of the cover  204  positioned about the expandable member  202 . 
     In some embodiments of the present disclosure, the first region  214  and the second region  216  may have different characteristics than those shown in  FIGS. 8A, 8B . For example, one or both of the first region  214  and the second region  216  may provide for a different surface topography than shown in the figures, a specific sequence of inflation (e.g., inflating from the middle region outwards to the end of the expandable member), a specific inflation shape (e.g., a consistent diameter along a working length of the expandable member), or other characteristics related to the inflation profile of the expandable member assembly. In some embodiments, one or both of the first region  214  and the second region  216  of the cover  104  may also include a coating that includes a therapeutic agent, a hydrophilic coating, a hydrophobic coating, or other suitable coatings for an expandable member assembly. Various combinations of therapeutic agents, textures, inflation profiles, and endoprosthesis may be used on the regions  214 ,  216  of the cover  104 . 
       FIGS. 10A and 10B  show a cross-sectional front-view of a portion of an expandable member assembly  300  of a medical device according to an embodiment of the present disclosure. The expandable member assembly  300  includes an expandable member  302  and a cover  304 .  FIG. 10A  shows the expandable member  302  in an uninflated state and  FIG. 10B  shows the expandable member  302  in a partially inflated state. The cover  304  may include two or more regions. Each of the two or more regions of the cover  304  may have different characteristics. For example, a first region  305  of the cover  304  overlaying the expandable member  302  in  FIGS. 10A and 10B  may comprise a radial strength or other characteristic configured to control the diameter of the cover  304  and thereby the diameter of the underlying expandable member  302  as the expandable member  302  is inflated. As shown in  FIG. 10A  the expandable member  302  in a deflated or partially inflated configuration may include pleats or wings  306 . Thought two wings  306  are shown in  FIG. 10A , in some embodiments more or fewer wings may be used, for example but not limited to 5 or 6. In some embodiments the pleats or wings  306  may be oriented along a longitudinal axis of the expandable member  302 , in other embodiments the pleats or wings  306  may be oriented along an axis that is perpendicular to the longitudinal axis. As the expandable member  302  inflates, the wings  306  may unfold. The torsional stress of the unfolding wings  306  can impart a force or stress on the wall of the vessel in which it is deployed. The first region  305  of the cover  304  overlaying the expandable member  302  may control the expansion of the expandable member  302  and may prevent the wings  306  from imparting a potentially damaging stress on the vessel wall as wings  306  unfold. In some embodiments, another region (not shown) of the cover  304  may comprise different characteristics, for example but not limited to a coating, a different radial strength, or a different surface topography. Another region of the cover  304  (not shown) may be positioned around the expandable member  302  before or after the first region  305  and may comprise different characteristics than that of the first region  205 . For example, the other region of the cover  304  may include a coating, a surface topography, varied radial strength along the length of the other region, a different coefficient of friction on the surface of the other region, or other characteristics. The cover  304  may be inverted into a cover lumen  308  of a catheter  310  and moved along the longitudinal axis of the catheter  310  to position the other region of the cover  304  over the expandable member  302 . In some embodiments, the cover  304  may include additional regions having the same or different characteristics as the other regions of the cover  304 . 
       FIG. 11  depicts a side view of a medical device that includes an expandable member assembly  350  and a catheter  353  according to an embodiment of the disclosure. The expandable member assembly  350  includes a cover  352  positioned around at least a portion of an expandable member  354 . The cover  352  also extends beyond a proximal end  355  of the expandable member  344  along a length of the catheter  353  towards a proximal end  355  of the catheter  353 . The cover  352  can include a first region  357 , shown in  FIG. 11  as surrounding the expandable member  354 . The cover  352  also includes a second region  358  that extends along a length of the catheter  353 . Each of the first region  357  and the second region  358  can have a length that is approximately equal to an overall length of the expandable member  354 , in some embodiments one or more of the first region  357  and the second region  356  may have a different length. A sheath  360  is positioned around at least a portion of the second region  358  of the cover  352 . The sheath  360  can comprise a polymer material or other suitable material. In some embodiments, the first region  357  and the second region  358  of the cover  352  can have different characteristics, for example but not limited to, different radial strengths, different surface textures, different surface topographies, and/or different coatings. 
     In an embodiment of the disclosure, the first region  357  of the cover  352  may include a variably permeable microstructure. At least one hydrophilic coating comprising at least one therapeutic agent may be disposed on the expandable member  354 . During use, with the first region  357  positioned around the expandable member  354 , the underlying hydrophilic coating becomes hydrated or partially hydrated and facilitates fluid transfer across the first region  357  of the cover  352 . However, the closed microstructure of the first region  357  in the unexpanded state prevents unwanted, premature release of the therapeutic agent in the unexpanded state. Upon expansion, the orientation or configuration of the microstructure of the material comprising the first region  357 , which is disposed over the expandable member, transforms from a substantially closed microstructure to a substantially open microstructure allowing the hydrated or partially hydrated coating to be transferred outward. This feature of the microstructure of the material is one embodiment of a material having a variably permeable microstructure. Once the hydrated or partially hydrated hydrophilic coating passes through the first region  357  of the cover  352 , the therapeutic agent is delivered to the treatment site. In one embodiment, the hydrated or partially hydrated coating comprises a therapeutic agent and once the first region  357  is expanded, the therapeutic agent transfers through the first region  357  of the cover  352 . In another embodiment, the first region  357  of the cover  352  has a relatively closed microstructure when there is no strain on the outer sheath. In another embodiment, the first region  357  has a more open microstructure when the first region  357  is strained (i.e., diametrically strained). The strain on the first region  357  can be exerted by the underlying expandable member during expansion. 
     Materials which may exhibit variably permeable microstructures are known to the art. These include, but are not limited to, fibrillated structures, such as expanded fluoropolymers (for example, ePTFE) or expanded polyethylene (as described in U.S. Pat. No. 6,743,388); fibrous structures (such as woven or braided fabrics; non-woven mats of fibers, microfibers, or nanofibers; materials made from processes such as electrospinning or flash spinning; polymer materials consisting of melt or solution processable materials such as fluoropolymers, polyamides, polyurethanes, polyolefins, polyesters, polyglycolic acid (PGA), polylactic acid (PLA), and trimethylene carbonate (TMC), and the like; films with openings created during processing (such as laser- or mechanically-drilled holes); open cell foams; microporous membranes made from materials such as fluoropolymers, polyamides, polyurethanes, polyolefins, polyesters, PGA, PLA, TMC, and the like; porous polyglycolide-co-trimethylene carbonate (PGA:TMC) materials (as described in U.S. Pat. No. 8,048,503); or combinations of the above. Processing of the above materials may be used to modulate, enhance or control permeability between a first, closed state and second, expanded. Such processing may help close the microstructure (thus lower permeability) in a first state, help open the microstructure in a second state, or a combination of both. Such processing which may help close the microstructure may include, but is not limited to: calendaring, coating (discontinuously or continuously), compaction, densification, coalescing, thermal cycling, or retraction and the like. Such processing that may help open the microstructure may include, but is not limited to: expansion, perforation, slitting, patterned densification and/or coating, and the like. In another embodiment, the materials comprise micropores between nodes interconnected by fibrils, such as in ePTFE. In another embodiment, the material comprises micropores in an essentially nodeless ePTFE, as described in U.S. Pat. No. 5,476,589. 
     Once the therapeutic agent has been eluted through the first region  357  by the expansion of the first region  357  of the cover  352 , the expandable member may be deflated and the cover  352  may be pulled through a cover lumen of the catheter  353  to move the second region  358  to be positioned about the expandable member  354 . The second region  358  may have a different permeable microstructure than the first region  357 . In some embodiments, the second region  356  may have a different nominal diameter than the first region  357 , a different surface topography, a different inflation profile, a different inflation sequence, and/or an additional coating on a surface of the second region  356 , as compared to the first region  357 . 
       FIG. 12  depicts a medical device  400  comprising an expandable member assembly  402  and a catheter  404  according to an embodiment of the disclosure. The expandable member assembly  402  may include a cover  406  positioned around an expandable member  408  at a distal section  410  of the catheter  404 . The cover  406  may extend along a length of the catheter  404  beyond a proximal end  412  of the expandable member  408 . In some embodiments, the cover  406  may not fully surround the expandable member  408 , as shown at the distal end  414 . The cover  406  may not fully surround the catheter  404 . Expandable member assembly  402 , in the embodiment depicted in  FIG. 12 , may comprise one or more lines  416 . The lines  416  may be inverted in a lumen of the catheter  404  and may be attached to an actuator (not shown) that can pull the cover  406  into and through a cover lumen of the catheter  404 . In some embodiments, the one or more lines  416  are integral with the cover  406 . In some embodiments, the one or more lines  416  are coupled to the cover  406 . 
       FIG. 13  depicts a medical device  500  including an expandable member assembly  501  according to an embodiment of the disclosure. The expandable member assembly  501  includes a cover  502  overlaying an expandable member  504 . The medical device  200  can include a catheter  506  to which the expandable member  504  and the cover  502  are attached. The catheter  506  may be in fluid communication with the expandable member  504 , such that fluid can be introduced through catheter  506  into expandable member  504 . The cover  502  is disposed on an outer surface of the expandable member  504  and extends beyond a proximal end  508  of the expandable member  504  along a length of the catheter  506  towards a proximal end  510  of the catheter  506 . The cover  502  may have a length that is two, three, four or more times greater than a working length of the expandable member  502  at a nominal diameter. Though not shown in  FIG. 13 , in some embodiments a sheath may be disposed about at least a portion of the cover  502  that extends along the catheter  506 . 
     The cover  502  may include multiple regions, for example but not limited to a first region  512 , a second region  514 , a third region  516 , and a fourth region  518 . In some embodiments, the cover  502  may include more or fewer regions. The various regions  512 ,  514 ,  516 , and  518  may have the same or different characteristics including nominal diameters, surface topographies, endoprosthesis, and/or therapeutic coatings. In the embodiment of the present disclosure shown in  FIG. 13 , the first region  512  of the cover  502  may include a characteristic that acts as a pre-treatment to a wall of a vessel prior to delivering an endoprosthesis (e.g., a stent) via a different region of the cover  502 . In some embodiments, the characteristic that acts as a pre-treatment may include a therapeutic coating (e.g., paclitaxel), a surface topography (e.g., a surface topography for removing plaque and/or other deposits from the wall of the vessel), or other suitable pre-treatment characteristics. In certain embodiments, the pre-treatment may be applying a vibration of the expandable member  504 , and in such embodiments the first region  512  may be strips or lines of the cover  502  and may not surround the expandable member  504  entirely. In some embodiments, the surface topography of the first region  512  may include apertures through which the expandable member  504  may expand and contact the wall of the vessel. 
     After expanding the expandable member  504  with the first region  512  of the cover  502  positioned about the expandable member  504  to provide the pre-treatment of the first region  512 , the expandable member  504  may be deflated and the cover  502  may be pulled through a cover lumen in the catheter  506  and moved through the cover lumen towards the proximal end  510  of the catheter  506 . As the first region  514  of the cover  502  is pulled off the expandable member  504  and through the cover lumen, the second region  514  of the cover  502  is moved in position around the expandable member  504 . 
     The expandable member  504  may be reinflated with the second region  514  positioned about the expandable member  504 . The second region  514  of the cover  502  may include an endoprosthesis, for example but not limited to a stent  520 . The stent  520  may be positioned about the second region  514  of the cover  502  and may be positioned about the expandable member  504  when the second region  514  is positioned about the expandable member  504 . The stent  520  may be a self-expanding stent, an expandable stent that is expanded by the expansion of the expandable member, or any other suitable types of stent, though in some embodiments other types of endoprosthesis may be used. With the second region  514  of the cover  502  positioned about the expandable member  504 , the stent  520  may be deployed within the wall of the vessel. In some embodiments, the second region  514  of the cover  502  may also have a specific sequence of inflation (e.g., inflating from the middle region outwards to the end of the expandable member), a specific inflation shape (e.g., a consistent diameter along a working length of the expandable member), or other characteristics related to the inflation profile of the expandable member assembly that may correspond to the type of endoprosthesis being deployed (e.g., may inflate from the center outwards, or from the ends inwards). Upon deployment of the stent  520  the expandable member  504  may be deflated and the second region  514  may be pulled through the cover lumen of the catheter  506  to position the third region  516  of the cover  502  about the expandable member  504 . 
     The expandable member  504  may be reinflated with the third region  516  positioned about the expandable member  504 . The third region  516  of the cover  502  may include a characteristic that acts as a post-treatment to the wall of the vessel subsequent to delivering the endoprosthesis (e.g., stent  520 ). The characteristic that acts as a post-treatment may include a therapeutic coating, for example but not limited to a therapeutic coating that minimizes stent restenosis, provides an anti-inflammatory effect, statins, atherosclerosis reversal, or other suitable post-treatment characteristics. Upon reinflation of the expandable member  504  with the third region  516  positioned about the expandable member  504 , the third region  516  may contact and provide the post-treatment to the wall of the vessel. In some embodiments, the cover  502  may not include a region for providing a post-treatment. In still yet other embodiments, the cover  502  may include multiple regions for providing one or more post-treatments after delivery of an endoprosthesis. After the inflation and expansion of the expandable member  504  with the third region  516  positioned about the expandable member  504  for providing the post-treatment, the expandable member  504  may be deflated and the cover  502  may be pulled through the cover lumen of the catheter  506  to position the third region  516  of the cover  502  about the expandable member  504 . 
     The expandable member  504  may be reinflated with the fourth region  518  positioned about the expandable member  504 . The fourth region  518  of the cover  502  may include another endoprosthesis, for example but not limited to an additional stent  522 . The additional stent  522  may be the same type of stent as stent  520  or may be a different type of stent  520 . In some embodiments, the stent  522  may be the same type of stent as stent  520  but may have a different diameter and/or a different length. With the fourth region  518  of the cover  502 , including the additional stent  522 , positioned about the expandable member  504 , the expandable member  504  may be inflated and the stent  522  may be deployed within the wall of the vessel. In some embodiments, the fourth region  518  of the cover  502  may also have a specific sequence of inflation (e.g., inflating from the middle region outwards to the end of the expandable member), a specific inflation shape (e.g., a consistent diameter along a working length of the expandable member), or other characteristics related to the inflation profile of the expandable member assembly that may correspond to the type of endoprosthesis being deployed (e.g., may inflate from the center outwards, or from the ends inwards). Upon deployment of the additional stent  522  the expandable member  504  may be deflated and the medical device  500  may be removed from the vessel of the patient. As described above with reference to  FIG. 13 , the medical device  500  that includes the cover  504  may permit the application of multiple treatments to the wall of a vessel without the removal of the medical device  500 , for example but not limited to providing for a pre-treatment, deployment of a stent, post-treatment, and the deployment of an additional stent. In some embodiments, the cover  504  may include more or fewer regions and each of the characteristics of the various regions of the cover  504  may be altered, removed, or otherwise changed. In some embodiments, additional endoprosthesis may be deployed, different pre and/or post treatments may be applied, additional or fewer pre or post treatments may be applied, and/or other changes to the characteristics of the regions of the cover  504  may be made. 
     As described herein, a cover of an expandable member assembly can comprise a plurality of regions having the same or different characteristics. The chart below provides examples of various combinations of the features described above with respect to one or more embodiments of the present disclosure. The chart below is not an exhaustive list of potential combinations as additional combinations of features are contemplated by this disclosure. In addition, “Region 1,” “Region 2,” Region 3,” and “Region 4” as recited below do not indicate any order of placement of the regions along a length of the catheter. For example, Region 3 may be positioned adjacent Region 1 and Region 4 etc. Nor does “Region 1,” “Region 2,” Region 3,” and “Region 4” indicate an order of deployment during use. In addition, the identification of a drug as “Drug 1,” “Drug 2,” “Drug 3,” “Drug 4” or when used in the same Example denotes a different drug. Thus, each of Drug 1, Drug 2, Drug 3, and Drug 4 in a single Example is optionally selected from the non-exclusive list of drugs below the heading “Therapeutic Agents” provided above, so long as each of Drug 1, Drug 2, Drug 3, and Drug 4 are different in each Example in which they appear together. Thus, “Drug 1” or similar notation (e.g. “Shape 1,” “Texture 1,” “Endoprosthesis 1”) repeated in a single Example refers to the same Drug (or other characteristic) within a single Example, but each such term does not indicate the same drug (shape or texture) between Examples. For example, “Drug 1” in Example No. 1 may be a different drug than “Drug 1” in Example No. 2, similarly “Shape 1” in Example No. 2 may be different than “Shape 1” in Example No. 3. Moreover, this list is not exhaustive any characteristic listed may be replaced by another, different characteristic. 
     Texture, as used below refers to a surface topography, for example but not limited to the surface topographies disclosed specifically herein (e.g., a surface topography defined by apertures, scored portions, beads, filaments, fibers, rings, knits, weaves, braids, and/or a densified material that alters a coefficient of friction of a surface of the cover). Shape, as used below refers to an inflation profile (e.g., a particular nominal diameter, working length, or other inflation shape) or a sequence of inflation along the region of the cover. Endoprosthesis, as used below refers to the inclusion of an endoprosthesis on the region of the cover (e.g., a stent). In some of the Examples below an “x” is used to indicate the cover does not include the region. In addition, each Example below could be modified by removing a region, adding a region, or changing a feature or characteristic of a region. 
     
       
         
           
               
               
               
               
               
             
               
                   
               
               
                 Example 
                 Region 1 
                 Region 2 
                 Region 3 
                 Region 4 
               
               
                   
               
             
            
               
                 Example No. 1 
                 No Drug 
                 Drug 1 
                 Drug 2 
                 Drug 3 
               
               
                 Example No. 2 
                 No Drug 
                 Drug 1 
                 Drug 2 
                 Shape 1 
               
               
                 Example No. 3 
                 No Drug 
                 Drug 1 
                 Shape 1 
                 Shape 2 
               
               
                 Example No. 4 
                 No Drug 
                 Texture 1 
                 Drug 1 
                 Shape 1 
               
               
                 Example No. 5 
                 No Drug 
                 Texture 1 
                 Drug 1 
                 Drug 2 
               
               
                 Example No. 6 
                 No Drug 
                 Texture 1 
                 Shape 1 
                 Shape 2 
               
               
                 Example No. 7 
                 No Drug 
                 Texture 1 
                 Texture 2 
                 Shape 
               
               
                 Example No. 8 
                 Shape 1 
                 No Drug 
                 Drug 1 
                 Drug 2 
               
               
                 Example No. 9 
                 Shape 1 
                 Drug 1 
                 Drug 2 
                 Drug 3 
               
               
                 Example No. 10 
                 Shape 1 
                 Drug 1 
                 Drug 2 
                 Texture 1 
               
               
                 Example No. 11 
                 Shape 1 
                 Drug 1 
                 Texture 1 
                 Texture 2 
               
               
                 Example No. 13 
                 Shape 1 
                 Drug 1 
                 Drug 2 
                 Shape 2 
               
               
                 Example No. 14 
                 Drug 1 
                 Drug 1 
                 Drug 2 
                 Drug 2 
               
               
                 Example No. 15 
                 Drug 1 
                 Drug 1 
                 Drug 1 
                 Drug 1 
               
               
                 Example No. 16 
                 Drug 1 
                 Drug 2 
                 Drug 3 
                 Drug 4 
               
               
                 Example No. 17 
                 Drug 1 
                 Drug 2 
                 Drug 3 
                 Drug 3 
               
               
                 Example No. 18 
                 Texture 1 
                 Texture 2 
                 Drug 1 
                 Drug 2 
               
               
                 Example No. 19 
                 Texture 1 
                 Texture 2 
                 Texture 3 
                 Shape 1 
               
               
                 Example No. 20 
                 Texture 1 
                 Texture 2 
                 Shape 1 
                 Shape 2 
               
               
                 Example No. 21 
                 Texture 1 
                 Shape 1 
                 Shape 2 
                 Drug 1 
               
               
                 Example No. 22 
                 Texture 1 
                 Drug 1 
                 Drug 2 
                 Drug 3 
               
               
                 Example No. 23 
                 Texture 1 
                 Drug 1 
                 Drug 2 
                 Shape 1 
               
               
                 Example No. 24 
                 Texture 1 
                 Shape 1 
                 Drug 1 
                 Drug 1 
               
               
                 Example No. 25 
                 Texture 1 
                 Drug 1 
                 Shape 1 
                 x 
               
               
                 Example No. 26 
                 Texture 1 
                 Drug 1 
                 Drug 2 
                 x 
               
               
                 Example No. 27 
                 Drug 1 
                 Drug 2 
                 Drug 3 
                 x 
               
               
                 Example No. 28 
                 Texture 1 
                 Drug 1 
                 Drug 2 
                 x 
               
               
                 Example No. 29 
                 Drug 1 
                 Drug 1 
                 Shape 1 
                 x 
               
               
                 Example No. 30 
                 Drug 1 
                 Drug 2 
                 Shape 1 
                 x 
               
               
                 Example No. 32 
                 Shape 1 
                 Shape 2 
                 Shape 3 
                 x 
               
               
                 Example No. 33 
                 Texture 1 
                 Texture 2 
                 Drug 1 
                 x 
               
               
                 Example No. 34 
                 Drug 1 
                 Drug 2 
                 x 
                 x 
               
               
                 Example No. 35 
                 Drug 1 
                 Drug 1 
                 x 
                 x 
               
               
                 Example No. 36 
                 Texture 1 
                 Drug 1 
                 x 
                 x 
               
               
                 Example No. 37 
                 Drug 1 
                 Surface 1 
                 x 
                 x 
               
               
                 Example No. 38 
                 Texture 1 
                 Surface 1 
                 x 
                 x 
               
               
                 Example No. 39 
                 Surface 1 
                 Surface 2 
                 x 
                 x 
               
               
                 Example No. 40 
                 Texture 1 
                 Texture 2 
                 x 
                 x 
               
               
                 Example No. 41 
                 No Drug 
                 Drug 1 
                 Texture 1 
                 Endoprosthesis 1 
               
               
                 Example No. 42 
                 Drug 1 
                 Texture 1 
                 Endoprosthesis 1 
                 Drug 2 
               
               
                 Example No. 43 
                 Drug 1 
                 Texture 1 
                 Texture 2 
                 Endoprosthesis 1 
               
               
                 Example No. 44 
                 Drug 1 
                 Texture 1 
                 Endoprosthesis 1 
                 Endoprosthesis 2 
               
               
                 Example No. 45 
                 Drug 1 
                 Endoprosthesis 1 
                 Endoprosthesis 2 
                 Drug 2 
               
               
                 Example No. 46 
                 Endoprosthesis 1 
                 Endoprosthesis 2 
                 Endoprosthesis 3 
                 Endoprosthesis 4 
               
               
                 Example No. 47 
                 Texture 1 
                 Texture 2 
                 Texture 3 
                 Endoprosthesis 1 
               
               
                 Example No. 48 
                 Drug 1 
                 Drug 1 
                 Texture 1 
                 Endoprosthesis 1 
               
               
                 Example No. 49 
                 Shape 1 
                 Drug 1 
                 Texture 1 
                 Endoprosthesis 1 
               
               
                 Example No. 50 
                 Shape 1 
                 Endoprosthesis 1 
                 Drug 1 
                 Drug 2 
               
               
                   
               
            
           
         
       
     
     The foregoing description of certain embodiments, including illustrated embodiments, has been presented only for the purpose of illustration and description and is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Numerous modifications, adaptations, and uses thereof will be apparent to those skilled in the art without departing from the scope of the disclosure.