System for minimally invasive delivery of medical devices

Abstract

A medical device delivery system includes a delivery catheter (102) and an in-line sheath (200), the delivery catheter (102) being preloaded within the in-line sheath (200). The delivery catheter (102) includes a catheter hub (110) and a catheter shaft (130). A catheter shaft (130) includes a proximal portion extending distally from the hub and slidably receiving a proximal narrow portion of the medical device, and a distal portion slidably receiving a distal wide portion of the medical device. The in-line sheath (200) includes a sheath hub (210) and a sheath shaft (230). A sheath shaft (230) includes a proximal portion extending distally from the sheath hub and slidably receiving at least a portion of the proximal portion of the catheter shaft, and an expandable distal portion slidably receiving the distal portion of the catheter shaft.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 317,498, filed on March 7, 2022, entitled “MEDICALDEVICE DELIVERY SYSTEM,” the disclosure of which is hereby incorporated by reference in its entirety for all purposes. Background Art

[0003] The present disclosure generally relates to the field of minimally invasive delivery of medical devices and / or therapies. Minimally invasive transcatheter delivery of medical devices and / or therapies to a target site in the body can be used to treat any number of conditions. Medical devices and / or therapies can be delivered into the heart to address various cardiac abnormalities. Summary of the invention

[0004] Methods and devices related to a medical device delivery system are described herein, which are configured to allow a medical device to be advanced through the delivery system to achieve minimally invasive transcatheter delivery of the medical device. The medical device delivery system may include a straight-through sheath and a delivery catheter associated with the straight-through sheath. For example, the delivery catheter may be preloaded in the straight-through sheath to facilitate the advancement of the medical device delivery system through a tortuous anatomical path.

[0005] The methods and structures for treating patients disclosed herein also encompass similar methods and structures performed on or placed on simulated patients, which are suitable for, for example, training; demonstration; program and / or device development; and the like. The simulated patient can be physical, virtual, or a combination of physical and virtual. The simulation can include a simulation of all or part of a patient, for example, the entire body, a part of the body (e.g., chest), a system (e.g., cardiovascular system), an organ (e.g., heart), or any combination thereof. The physical element can be: natural, including a human or animal body or part thereof; synthetic; or any combination of natural and synthetic. The virtual element can be entirely in silica, or covered on one or more physical parts. The virtual element can be presented on any combination of a screen, headphones, holograms, projections, speakers, headphones, pressure transducers, temperature transducers, or any combination using suitable technology.

[0006] Certain aspects, advantages, and novel features have been described herein for purposes of summarizing the present disclosure. It should be understood that not all such advantages may be achieved according to any particular example. Thus, the disclosed examples may be performed in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] For the purpose of illustration, various examples are depicted in the accompanying drawings, and these examples should not be construed as limiting the scope of the present invention. In addition, various features of different disclosed examples can be combined to form additional examples as part of the present disclosure. In all drawings, reference numerals may be reused to indicate the corresponding relationship between reference elements. However, it should be understood that the use of similar reference numerals in conjunction with multiple drawings does not necessarily imply the similarity between the various examples associated therewith. In addition, it should be understood that the features of the various drawings are not necessarily drawn to scale, and the size of the illustrations thereof is presented for the purpose of illustrating its inventive aspects. In general, some of the features shown may be relatively small compared to the features shown in some examples or configurations.

[0008] Figure 1 A cross-section of a human heart.

[0009] Figure 2A , 2B 2C are side cross-sectional views of examples of medical device delivery systems.

[0010] Figure 3A , 3B and 3C are side cross-sectional views of a sheath delivery system including the medical device delivery system described with reference to FIG. 2 positioned through an outer expandable sheath.

[0011] Figure 4 is a perspective view of an example of a sheath shaft including an expandable distal portion including an expandable coil.

[0012] Figure 5 is a perspective view of an example of a sheath shaft including an expandable distal portion including a shape memory material.

[0013] Figure 6 is a perspective view of an example of a sheath shaft including an expandable distal portion comprising a plurality of discrete elongated sections disposed circumferentially about a delivery catheter tube extending through the sheath shaft.

[0014] Fig. 7A is a side view of an example of a sheath shaft including an expandable distal portion, and Figure 7B is a side cross-sectional view thereof, wherein the expandable distal portion includes a plurality of discrete elongated portions, each of which extends distally along an axis parallel or substantially parallel to the longitudinal axis of the sheath shaft.

[0015] Fig. 8A is a side view of an example of a sheath shaft including an expandable distal portion, and Figure 8Bis a side cross-sectional view thereof, the expandable distal portion includes a plurality of discrete elongated portions, each discrete elongated portion having a bend on a proximally directed end portion.

[0016] Fig. 9A is a side view of an example of a sheath shaft including an expandable distal portion, and Fig. 9B is a side cross-sectional view thereof, wherein the expandable distal portion includes a plurality of discrete elongated portions, each of which extends from a proximal end to a distal end along a convex curved path.

[0017] Fig. 10A is a side view of an example of a sheath shaft including an expandable distal portion, and Fig. 10B is a side cross-sectional view thereof, the expandable distal portion includes a plurality of discrete elongated portions, each discrete elongated portion having a convex curvature on a proximally directed end portion.

[0018] Fig.11 is a side perspective view of a sheath shaft comprising three sections, each section comprising a different material than the other sections.

[0019] Fig.12 is a side cross-sectional view illustrating a distal end of an example sheath shaft, wherein the distal end can be configured to mate with a distal portion of a medical device received within the sheath shaft.

[0020] Fig.13 is a side cross-sectional view illustrating a distal end of another example of a sheath shaft, wherein the distal end can be configured to mate with a distal portion of a medical device received within the sheath shaft.

[0021] Fig.14 is a flow chart of an example of a process for deploying a medical device using a medical device delivery system as described herein.

[0022] Fig.15 is a flow chart of an example of a process for making a medical device delivery system as described herein. DETAILED DESCRIPTION

[0023] The headings provided herein are for convenience only and do not necessarily affect the scope or meaning of the claimed invention.

[0024] The present disclosure provides systems, devices and methods related to a medical device delivery system, which can be used to facilitate the delivery of a medical device to a target site via a catheter in a minimally invasive manner. The medical device delivery system may include a straight-insert sheath and a delivery catheter preloaded in the straight-insert sheath. The medical device may include a proximal narrow portion and a distal wide portion, and the lateral cross-sectional size included in the distal wide portion is larger than the lateral cross-sectional size of the proximal narrow portion. The medical device can be preloaded into the delivery catheter so that the proximal narrow portion is received in the proximal portion of the catheter shaft of the delivery catheter, and the distal wide portion is received in the distal portion of the catheter shaft. The delivery catheter including the medical device preloaded therein can be preloaded in the straight-insert sheath so that the proximal portion of the catheter shaft is received in the proximal portion of the sheath shaft of the straight-insert sheath, and the distal portion of the catheter shaft is received in the expandable distal portion of the sheath shaft. The preload of a medical device delivery system including a delivery catheter (wherein the medical device is received in the delivery catheter) in the straight-insert sheath can facilitate the medical device delivery system to advance through a tortuous anatomical path.

[0025] Although certain preferred examples and instances are disclosed below, the subject matter of the invention extends beyond the specifically disclosed instances to other alternative instances and / or uses and modifications and equivalents thereof. Therefore, the scope of the resulting claims is not limited to any of the specific examples described below. For example, in any method or process disclosed herein, the actions or operations of the method or process may be performed in any suitable order and are not necessarily limited to any particular disclosed order. Various operations may be described as multiple discrete operations in sequence in a manner that may help understand certain instances; however, the order of description should not be interpreted as implying that these operations are order-dependent. In addition, the structures, systems, and / or devices described herein may be embodied as integrated components or separate components. In order to compare various embodiments, certain aspects and advantages of these instances are described. Not all of these aspects or advantages are necessarily achieved by any particular embodiment. Therefore, for example, various instances may be implemented in a manner that realizes or optimizes an advantage or a group of advantages taught herein, without necessarily realizing other aspects or advantages also taught or suggested herein.

[0026] Some standard anatomical terms of position are used herein to refer to the anatomy of animals (i.e., humans) with respect to preferred examples. Although some spatially relative terms, such as "external", "interior", "upper", "lower", "below", "above", "vertical", "horizontal", "top", "bottom" and similar terms, are used herein to describe the spatial relationship between a device / element or anatomical structure and another device / element or anatomical structure, it should be understood that for ease of description, these terms are used herein to describe the positional relationship between elements / structures, as shown in the figure. It should be understood that, in addition to the orientations depicted in the accompanying drawings, spatially relative terms are intended to cover different orientations of elements / structures in use or operation. For example, an element / structure described as "above" another element / structure can represent a position below or beside such other element / structure relative to an alternative orientation of a subject patient or element / structure, and vice versa.

[0027] Figure 1 is a schematic diagram showing various features of a human heart 1. The heart 1 includes four chambers, namely the left atrium 2, the left ventricle 3, the right ventricle 4, and the right atrium 5. A muscular wall called the septum 10 separates the left atrium 2 from the right atrium 5 and the left ventricle 3 from the right ventricle 4. Blood flow through the heart 1 is at least partially controlled by the following four valves: the mitral valve 6, the aortic valve 7, the tricuspid valve 8, and the pulmonary valve 9. The mitral valve 6 separates the left atrium 2 from the left ventricle 3 and controls the blood flow therebetween. The aortic valve 7 separates the left ventricle 3 from the aorta 12 and controls the blood flow therebetween. The tricuspid valve 8 separates the right atrium 5 from the right ventricle 4 and controls the blood flow therebetween. The pulmonary valve 9 separates the right ventricle 4 from the pulmonary trunk or artery 11, thereby controlling the blood flow therebetween.

[0028] In a healthy heart, the heart can receive deoxygenated blood from the rest of the body (generally into the right side of the heart for delivery to the lungs), and receive oxygenated blood from the lungs (generally into the left side of the heart for delivery to the rest of the body). During ventricular diastole, deoxygenated blood reaches the right atrium 5 from the inferior vena cava 15 and the superior vena cava 16 to flow into the right ventricle 4, and oxygenated blood reaches the left atrium 2 from the pulmonary veins to flow into the left ventricle 3. During ventricular systole, deoxygenated blood from the right ventricle 4 can flow into the pulmonary trunk 11 for delivery to the lungs (e.g., via the left pulmonary artery 14 and the right pulmonary artery 13), and oxygenated blood can flow from the left ventricle 3 to the aorta 12 for delivery to the rest of the body.

[0029] Many conditions can inhibit the ability of heart 1 to pump enough blood through it. For example, coronary heart disease, heart inflammation, and / or high blood pressure can cause reduced blood flow to heart 1. Mitral valve dysfunction can cause increased left atrial pressure. Conditions such as mitral regurgitation and / or stenosis can make it difficult to pump blood from the left atrium to the left ventricle, resulting in increased pressure in the left atrium. Dysfunction in the left ventricle 3 can also cause increased left atrial pressure.

[0030] The disclosure herein provides one or more devices and methods related to a medical device delivery system, the medical device delivery system comprising an in-line sheath and a delivery catheter associated with the in-line sheath. For example, the delivery catheter can be preloaded in the in-line sheath. The medical device delivery system can facilitate minimally invasive transcatheter delivery of a medical device to a target site, the target site comprising a target site within the heart, including within a cardiac chamber, such as a left ventricle. The in-line sheath may have a sheath shaft, the sheath shaft comprising a proximal portion and an expandable distal portion, the expandable distal portion being configured to present an expanded state and a collapsed state. When the expandable distal portion is in the expanded state, the delivery catheter can be preloaded in the in-line sheath so that at least a portion of the proximal portion of the catheter shaft of the delivery catheter can be received in the proximal portion of the sheath shaft, and the distal portion of the catheter shaft can be received in the expandable distal portion. For example, the delivery catheter can be preloaded in the delivery catheter body of the in-line sheath.

[0031] In some cases, the medical device can be preloaded in the delivery catheter. The medical device may include a proximal narrow portion and a distal wide portion, and the distal wide portion includes a lateral cross-sectional size greater than the lateral cross-sectional size of the proximal narrow portion. The distal portion of the catheter shaft may have a lateral cross-sectional size larger than its proximal portion, for example to accommodate the distal wide portion of the medical device. Deploying the medical device may include translating the medical device distally relative to the delivery catheter and / or translating the delivery catheter distally relative to the in-line sheath to position the distal wide portion of the medical device at the distal end of the catheter shaft, respectively, and positioning the distal portion of the catheter shaft at the distal end of the sheath shaft. Retracting the medical device may include withdrawing the distal wide portion back into the distal portion of the catheter shaft. The distal portion of the catheter shaft may then be retracted into the expandable distal portion of the sheath shaft. When the in-line sheath is retracted through the anatomical path, the distal wide portion of the medical device can be retained in the distal portion of the catheter shaft, and the distal portion of the catheter shaft can be retained in the expandable distal portion of the in-line sheath.

[0032] The delivery catheter including the medical device preloaded therethrough can be preloaded in the straight-insert sheath so that the distal portion of the catheter shaft and / or the distal wide portion of the medical device will not advance through the proximal portion of the sheath shaft when the medical device is deployed and retracted. The delivery catheter carrying the preloaded medical device is preloaded in the straight-insert sheath to facilitate the use of the straight-insert sheath, the straight-insert sheath comprising a sheath shaft, the sheath shaft comprising a proximal portion with a reduced profile and / or a proximal portion comprising a material different from the material of the expandable distal portion. The reduced profile of the proximal portion of the sheath shaft can facilitate blood flow around it. Using different materials for the proximal portion and the expandable distal portion can facilitate the desired torque capacity of the proximal portion to be used for crossing a tortuous anatomical path, while allowing the distal wide portion of the medical device to be expected to be contained in the expandable distal portion. In some cases, the straight-insert sheath and the delivery catheter can be manufactured together so that the delivery catheter can be preloaded in the straight-insert sheath.

[0033] In some cases, the expandable distal portion of the sheath shaft may include a tubular configuration. In some cases, the expandable distal portion may include a forked configuration. For example, the expandable distal portion may include a plurality of discrete elongated portions extending distally from a proximal portion of the sheath shaft. The plurality of discrete elongated portions may be disposed around corresponding portions of a delivery catheter body, such as at least partially defining the delivery catheter body. Each discrete elongated portion may be configured to rotate outwardly about its proximal end to assume an expanded state so as to accommodate a distal wide portion of a medical device received within the distal portion of the catheter shaft.

[0034] The medical device can be configured to treat any number of conditions including various heart diseases. In some cases, the medical device can be configured to provide improved blood flow through the heart. For example, the medical device may include a mechanical circulatory support (MCS) mechanism. In some cases, the medical device may include a heart pump. In some cases, at least a portion of the medical device (e.g., a distal wide portion) can be positioned in a cardiac chamber, such as the left ventricle. The medical device can be configured to pump blood from the left ventricle into the aorta, thereby delivering oxygen-rich blood to the body. As described herein, the medical device delivery system can facilitate improving blood flow around the system during a deployment procedure. The improved blood flow can then facilitate the execution of more complex procedures, such as procedures requiring longer durations, including procedures for delivering mechanical circulatory support (MCS) devices.

[0035] The straight-insert sheath including a delivery catheter and a medical device preloaded therein can be advanced by an outer expandable sheath positioned in the body. In some cases, the outer expandable sheath can be positioned into the body through an opening in the iliac artery or the femoral artery. The straight-insert sheath can be configured to provide mechanical column strength to reduce or prevent damage to the delivery catheter and / or the medical device due to the radial compression force applied thereon, such as the radial compression force applied by the outer expandable sheath when the delivery system advances through the expandable portion of the outer expandable sheath. In some cases, the straight-insert sheath can advance to position the expandable distal portion of the sheath shaft at the distal end of the outer expandable sheath, and be positioned in the desired chamber, blood vessel and / or passage, such as the aorta, including the descending aorta or the abdominal aorta. After the expandable distal portion of the sheath shaft advances and leaves the outer expandable sheath, the delivery catheter can advance to position the distal portion of the catheter shaft at the distal end of the sheath shaft. Then, the distal wide portion of the medical device can be deployed from the catheter shaft and positioned at the target site. In some cases, the distal wide portion of the medical device can be positioned in the left ventricle.

[0036] Any of the various systems, devices, equipment, etc. in the present disclosure may be sterilized (e.g., using heat, radiation, ethylene oxide, hydrogen peroxide, etc.) to ensure that they are safe for use with patients, and the methods herein may include sterilizing (e.g., using heat, radiation, ethylene oxide, hydrogen peroxide, etc.) the associated systems, devices, equipment, etc.

[0037] The term "associated with" is used herein according to its broad and ordinary meaning. For example, where a first feature, element, component, device or member is described as being associated with a second feature, element, component, device or member, such description should be understood to indicate that the first feature, element, component, device or member is directly or indirectly physically coupled, attached or connected, integrated, at least partially embedded in, or otherwise physically associated with the second feature, element, component, device or member.

[0038] Although the target site is primarily described herein as being within a cardiac chamber, such as a ventricle, it is understood that the target site can be within any number of other organs, chambers, lumens, and / or blood vessels. The medical device can be delivered to any number of other organs, chambers, lumens, and / or blood vessels to treat conditions other than cardiac abnormalities.

[0039] Figure 2A , 2B2C are side cross-sectional views of an example of a medical device delivery system 100. The medical device delivery system 100 may include a delivery catheter 102 and an in-line sheath 200 associated with the delivery catheter 102. The delivery catheter 102 may include a catheter hub 110 and a catheter shaft 130. The catheter shaft 130 may include a medical device conduit 136 extending through the catheter shaft 130, the medical device conduit 136 being configured to slidably receive at least a portion of a medical device. A proximal portion 132 of the catheter shaft 130 may be coupled to the catheter hub 110, such as a distal portion 112 of the catheter hub 110. For example, the catheter shaft 130 may extend distally from the catheter hub 110, including extending distally from a distal end 114 of the catheter hub 110. The in-line sheath 200 may include a sheath hub 210 and a sheath shaft 230. The sheath shaft 230 may include a delivery catheter tube 236 extending through the sheath shaft 230 and configured to slidably receive at least a portion of the catheter shaft 130. The sheath shaft 230 may include a proximal portion 232 and an expandable distal portion 234. The sheath shaft 230 (e.g., the proximal portion 232) may extend distally from the sheath hub 210. The proximal portion 232 of the sheath shaft 230 may be coupled to the sheath hub 210. As described in further detail herein, the expandable distal portion 234 may assume an expanded state configured to accommodate the distal portion 134 of the catheter shaft 130, and assume a collapsed state when the distal portion 134 of the catheter shaft 130 is advanced to leave the distal end of the expandable distal portion 234 and is positioned distal to the expandable distal portion. In some cases, the medical device delivery system 100 including the delivery catheter 102 preloaded within the in-line sheath 200 may be advanced through the outer expandable sheath to facilitate delivery of the medical device to the target site.

[0040] The in-line sheath 200 can be associated with the delivery catheter 102. For example, when the expandable distal portion 234 is in the expanded state, the delivery catheter 102 can be preloaded within the in-line sheath 200 such that at least a portion of the proximal portion 132 of the catheter shaft 130 is received within the proximal portion 232 of the sheath shaft 230, and the distal portion 134 of the catheter shaft 130 is received within the expandable distal portion 234 of the sheath shaft 230. In some cases, the in-line sheath 200 and the delivery catheter 102 can be manufactured together such that the delivery catheter 102 is preloaded within the in-line sheath 200. The proximal portion 132 of the catheter shaft 130 can be preloaded within the proximal portion 232 of the sheath shaft 230, and the distal portion 134 of the catheter shaft 130 can be preloaded within the expandable distal portion 234 of the sheath shaft 230, such that the distal portion 134 of the catheter shaft 130 does not need to be slidably received within the proximal portion 232 of the sheath shaft 230. As described in further detail herein, the distal portion 134 of the catheter shaft 130 can have a larger lateral cross-section than the lateral cross-section of the proximal portion 132 of the catheter shaft 130. Since the distal portion 134 of the catheter shaft 130 does not need to be advanced through the proximal portion 232, the proximal portion 232 of the sheath shaft 230 does not need to adopt a larger lateral cross-section to accommodate the larger distal portion 134 of the catheter shaft 130. When positioned in a patient, the reduced profile of the proximal portion 232 of the sheath shaft 230 can facilitate blood flow therearound. Because the proximal portion 232 does not accommodate the larger distal portion 134 of the catheter shaft 130, the proximal portion 232 may include at least a portion made of a material that is more rigid than the material used for the expandable distal portion 234, thereby improving traversal through tortuous anatomical pathways.

[0041] refer to Figure 2A, the proximal portion 132 of the catheter shaft 130 may be configured to slidably receive at least a portion of the proximal narrow portion of the medical device. The distal portion 134 of the catheter shaft 130 may be configured to slidably receive a distal wide portion of the medical device and / or a portion of the proximal narrow portion of the medical device. The distal wide portion may include a lateral cross-sectional size that is greater than the lateral cross-sectional size of the proximal narrow portion. The lateral cross-section may be perpendicular or substantially perpendicular to the longitudinal axis of the medical device. For example, the distal wide portion may have a diameter wider than the diameter of the proximal narrow portion of the medical device. In some cases, the medical device may be preloaded in the delivery catheter 102. For example, at least a portion of the proximal narrow portion of the medical device may be received in the proximal portion 132 of the catheter shaft 130, and the distal wide portion of the medical device may be received in the distal portion 134 of the catheter shaft 130. Deploying the medical device may include translating the medical device distally relative to the delivery catheter 102 such that a distal wide portion of the medical device is positioned distal to an opening at a distal end 138 of the catheter shaft 130 and a portion of a proximal narrow portion of the medical device is received within a distal portion 134 of the catheter shaft 130.

[0042] In some cases, the distal portion 134 of the catheter shaft 130 can have a lateral cross-section that is sized to accommodate a distal wide portion of a medical device. For example, the distal portion 134 can include a lateral cross-section that is larger than a lateral cross-section of the proximal portion 132. The lateral cross-section can be perpendicular or substantially perpendicular to the longitudinal axis of the catheter shaft 130. The distal portion 134 can have a diameter that is wider than the diameter of the proximal portion 132. For example, the outer diameter and / or inner diameter of the proximal portion 132 (including the diameter of the medical device catheter 136) can be smaller than the outer diameter and / or inner diameter of the distal portion 134.

[0043] In some instances, when in the expanded state, the expandable distal portion 234 of the sheath shaft 230 can have a lateral cross-section that is sized to accommodate the distal portion 134 of the catheter shaft 130. For example, when in the expanded state, the expandable distal portion 234 can include a lateral cross-section that is larger than the lateral cross-section of the proximal portion 232. The lateral cross-section can be perpendicular or substantially perpendicular to the longitudinal axis of the sheath shaft 230. The expandable distal portion 234 can have a diameter that is wider than the diameter of the proximal portion 232. For example, the outer diameter and / or inner diameter of the proximal portion 232 (including the diameter of the delivery catheter tube 236) can be smaller than the outer diameter and / or inner diameter of the expandable distal portion 234.

[0044] In some cases, the sheath hub 210 may include an outer sheath engagement feature 250, which is configured to engage with the outer expandable sheath to prevent or reduce the distal translation and proximal translation of the plug-in sheath 200 relative to the outer expandable sheath. In some cases, the outer sheath engagement feature 250 can be configured to prevent or reduce the rotational movement of the plug-in sheath 200 relative to the outer expandable sheath, such as rotating around the longitudinal axis of the plug-in sheath 200. In some cases, the outer sheath engagement feature 250 can be configured to engage with the outer sheath hub of the outer expandable sheath. For example, the outer sheath engagement feature 250 may include at least a portion on the distal end 214 of the sheath hub 210. The distal end 214 of the sheath hub 210 can be positioned against or near the proximal end of the outer sheath hub so that the outer sheath engagement feature 250 can be triggered, activated and / or engaged to fix the relative rotation and translation position of the outer expandable sheath and the plug-in sheath 200.

[0045] In some cases, the sheath hub 210 can include a catheter engagement feature 252 configured to engage with a portion of the delivery catheter 102 to prevent or reduce distal and proximal translation of the delivery catheter 102 relative to the in-line sheath 200. In some cases, the catheter engagement feature 252 can be configured to prevent or reduce rotational movement of the delivery catheter 102, such as rotation about the longitudinal axis of the delivery catheter 102. In some cases, the catheter engagement feature 252 can be configured to frictionally contact a portion of the catheter shaft 130 extending through the sheath hub 210. The catheter engagement feature 252 can be triggered, activated, and / or engaged so that one or more portions thereof can frictionally contact a portion of the catheter shaft 130. For example, after the distal portion 134 of the catheter shaft 130 is in a desired position distal to the expandable distal portion 234, the catheter engagement feature 252 can engage with a portion of the catheter shaft 130 extending through the sheath hub 210.

[0046] Figure 2B and 2C The expandable distal portion 234 of the sheath shaft 230 is shown in greater detail. As described herein, the expandable distal portion 234 can be configured to assume an expanded state or a collapsed state. When in the expanded state, the expandable distal portion 234 can be configured to slidably receive the distal portion 134 of the catheter shaft 130. For example, when in the expanded state, the expandable distal portion 234 can include an outer diameter and / or inner diameter that is greater than the outer diameter and / or inner diameter of the proximal portion 232 of the sheath shaft 230. Figure 2B and 2CThe expandable distal portion 234 is shown in an expanded state while the distal portion 134 of the catheter shaft 130 is received by the expandable distal portion 234. When the expandable distal portion 234 of the sheath shaft 230 is in a collapsed state, a portion of the proximal portion 132 of the catheter shaft 130 can be received by the expandable distal portion 234. For example, after the distal portion 134 of the catheter shaft 130 is advanced distally out of the opening at the distal end 238 of the sheath shaft 230 and a portion of the proximal portion 132 of the catheter shaft 130 is received in the expandable distal portion 234, the expandable distal portion 234 of the sheath shaft 230 can assume the collapsed state.

[0047] In some cases, expandable distal portion 234 of sheath shaft 230 can include a tubular configuration. In some cases, expandable distal portion 234 can include a cylindrical shape when in the expanded state.

[0048] refer to Figure 2C In some cases, the proximally directed portion 242 of the expandable distal portion 234 may include an inclined profile to provide a transition from a narrower proximal portion 232 to a wider lateral cross-section of the expandable distal portion 234. In some cases, the inclined profile can provide a space between the catheter shaft 130 received within the delivery catheter body 236 and the sheath shaft 230. In some cases, the space can be configured to accommodate a portion of a guidewire that is configured to pass through the medical device to facilitate deployment of the medical device. In some cases, the distally directed portion 244 of the expandable distal portion 234 can provide a space between the catheter shaft 130 received within the delivery catheter body 236 and the sheath shaft 230, such as at the distal portion 134 of the catheter shaft 130. The space can be configured to accommodate a portion of a guidewire that is configured to pass through the medical device to facilitate deployment of the medical device.

[0049] In some cases, the medical device can be preloaded in the delivery catheter 102 such that the distal wide portion of the medical device is disposed in the distal portion 134 of the catheter shaft 130, and the proximal narrow portion of the medical device is disposed in the proximal portion 132 of the catheter shaft 130. It should be noted that for simplicity, the medical device is not shown. The delivery catheter 102 including the medical device preloaded therein can be preloaded in the straight-through sheath 200 such that the proximal portion 132 of the catheter shaft 130 is disposed in the proximal portion 232 of the sheath shaft 230, and the distal portion 134 of the catheter shaft 130 is received in the expandable distal portion 234. The delivery catheter 102 including the medical device preloaded therein can be translated distally relative to the straight-through sheath 200 so that the distal portion 134 of the catheter shaft 130 carrying the preloaded medical device can extend out of the straight-through sheath 200. For example, deploying the medical device may include advancing the delivery catheter 102 distally relative to the in-line sheath 200 to position the distal portion 134 of the catheter shaft 130 distal to the distal end 238 of the sheath shaft 230. Subsequently, the medical device may be advanced distally relative to the delivery catheter 102 to position the distal wide portion of the medical device distal to the distal end of the catheter shaft 130.

[0050] In some cases, the proximal portion 232 of the sheath shaft 230 may include a material different from the material of the expandable distal portion 234. In some cases, the proximal portion 232 may include a flexible material. In some cases, the expandable distal portion 234 may include a material that is both flexible and expandable. In some cases, the sheath shaft 230 may include a laser-cut hypotube that provides the desired flexibility, torque capacity, and / or expandability. In some cases, the hypotube may include stainless steel and / or a shape memory material (e.g., nitinol). In some cases, the sheath shaft 230 may include a polyamide (e.g., nylon) and / or a thermoplastic elastomer (e.g., polyether block amide). In some cases, one or more portions of the sheath shaft 230 may include a radiopaque material to facilitate visualization of the sheath shaft 230 during deployment (including at the distal end 238 of the sheath shaft 230). In some cases, one or more portions of the sheath shaft 230 may include a hydrophilic coating thereon to facilitate advancement of the sheath shaft 230, including passing through the outer expandable sheath.

[0051] In an alternative, the sheath shaft may include a non-expandable distal portion. The distal portion of the sheath shaft may not expand and / or collapse. For example, the non-expandable distal portion may have a larger lateral cross-section, for example, than the proximal portion of the sheath shaft, configured to accommodate the distal portion of the catheter shaft of the distal wide portion of the carrying medical device. After the distal portion of the catheter shaft advances distally and leaves the distal portion of the sheath shaft, the non-expandable distal portion of the sheath shaft may not collapse. For example, whether or not the distal portion of the catheter shaft is received by the non-expandable distal portion, the non-expandable distal portion can maintain or substantially maintain its configuration, such as a larger cross-sectional size than the proximal portion of the sheath shaft.

[0052] In some cases, the non-expandable distal portion may have the same configuration as the expandable distal portion 234 of the sheath shaft 230 in the expanded state as described with reference to FIG. The non-expandable distal portion may include a size and shape that is the same as the size (including cross-sectional size) and shape of the expandable distal portion 234 in the expanded state. For example, the non-expandable distal portion may include a tubular configuration, including a cylindrical shape. In some cases, the non-expandable distal portion may maintain or substantially maintain a cylindrical shape regardless of whether the distal portion of the catheter shaft is received by the non-expandable distal portion. In some cases, the proximally oriented portion of the non-expandable distal portion may include an inclined profile to provide a transition from a narrower proximal portion to a wider lateral cross-section of the non-expandable distal portion.

[0053] Figure 3A , 3B 3C is a side cross-sectional view of a sheath delivery system 300 including the medical device delivery system 100 described with reference to FIG. 2 positioned through an outer expandable sheath 302. Figure 3A, the outer expandable sheath 302 may include an outer sheath hub 310 and an outer sheath shaft 330. The outer sheath shaft 330 may include a proximal portion 332 and a distal portion 334. The outer sheath shaft 330 may be coupled to the sheath hub 310, for example extending distally from the outer sheath hub 310, including extending from a distal end 314 of the sheath hub 310. The medical device delivery system 100 may include a delivery catheter 102 preloaded within the in-line sheath 200. At least a portion of the sheath shaft 230 including at least a portion of the catheter shaft 130 preloaded therethrough may be advanced through the outer expandable sheath 302. For example, the sheath shaft 230 including at least a portion of the catheter shaft 130 preloaded therethrough may be advanced through the outer sheath hub 310 and the outer sheath shaft 330. In some cases, the medical device can be preloaded within the delivery catheter 102 such that the distal wide portion of the medical device is disposed within the distal portion 134 of the catheter shaft 130 and at least a portion of the proximal narrow portion of the medical device is disposed within the proximal portion 132 of the catheter shaft 130. The delivery catheter 102 including the medical device preloaded therein can be preloaded within the in-line sheath 200.

[0054] As the sheath shaft 230 is advanced through the outer sheath hub 310 and the outer sheath shaft 330, the sheath shaft 230 can provide structural support and / or protection for the catheter shaft 130 and the medical device carried by the catheter shaft 130. The outer sheath hub 310 may include one or more seals, including one or more hemostatic seals. For example, as the in-line sheath 200 is translated distally relative to the outer expandable sheath 302, the sheath shaft 230 can be advanced through the first seal 320 and the second seal 322 contained in the outer sheath hub 310. As the sheath shaft 230 is advanced through the seals 320, 322, the sheath shaft 230 can provide mechanical column strength and / or protection for the catheter shaft 130 and the medical device preloaded therein.

[0055] In some cases, the outer sheath shaft 330 can include at least a portion that is expandable. For example, prior to insertion of the delivery system 100 through the outer sheath shaft 330, at least a portion of the outer sheath shaft 330 can be in a collapsed state. As the sheath shaft 230 is advanced therethrough, a corresponding expandable portion of the outer sheath shaft 330 can assume an expanded state. Contact between the corresponding expandable portion of the outer sheath shaft 330 and the sheath shaft 230 can expand the outer sheath shaft 330 so that the outer sheath shaft 330 can assume an expanded state. As the sheath shaft 230 is advanced through the outer sheath shaft 330, the sheath shaft 230 can provide mechanical column strength to the catheter shaft 130 and the medical device.

[0056] Figure 3AAn expandable distal portion 234 of the sheath shaft 230 is shown disposed distally of a distal end 338 of the outer sheath shaft 330. For example, the in-line sheath 200 can be translated distally relative to the outer expandable sheath 302 such that the expandable distal portion 234 is advanced through the outer sheath shaft 330 from the proximal end 336 to the distal end 338. The expandable distal portion 234 can be advanced distally out of an opening 340 at the distal end 338. For example, a portion of the proximal portion 232 of the sheath shaft 230 can be positioned through the opening 340 and another portion of the proximal portion 232 of the sheath shaft 230 can be disposed within the outer sheath shaft 330. As the expandable distal portion 234 of the sheath shaft 230 is advanced distally out of the outer sheath shaft 330, the expanded portion of the outer sheath shaft 330 can present a reduced profile. In some cases, the reduction in the profile of the outer sheath shaft 330 can facilitate blood flow around it, thereby providing improved blood flow to the tissue during the procedure, and reducing complications and / or facilitating a procedure of increased duration. As described herein, at least a portion of the outer sheath shaft 330 can be in a collapsed state prior to inserting the medical device delivery system 100 through the outer sheath shaft 330. As the sheath shaft 230 is advanced through the outer sheath shaft 330, the expandable portion of the outer sheath shaft 330 can expand to accommodate the sheath shaft 230. The collapsed portion can apply friction and radial compression forces on the sheath shaft 230 during advancement of the sheath shaft 230. The sheath shaft 230 can be configured to provide a desired mechanical column strength to prevent or reduce damage to the catheter shaft 130 and / or a medical device received therein.

[0057] The outer sheath engagement feature 250, which includes at least a portion on the distal end 214 of the sheath hub 210, can be configured to engage with the outer expandable sheath 302 to prevent or reduce distal and proximal translation and / or rotation of the push-in sheath 200 relative to the outer expandable sheath 302. The outer sheath engagement feature 250 can engage with the push-in sheath engagement feature 350 of the outer sheath hub 310. The push-in sheath engagement feature 350 can include at least a portion on the proximal end 312 of the outer sheath hub 310. The outer sheath engagement feature 250 can engage with the push-in sheath engagement feature 350 to fix the relative translation and / or rotational position of the outer expandable sheath 302 and the push-in sheath 200 after the expandable distal portion 234 is in a desired position distal to the distal end 338 of the outer sheath shaft 330. In some cases, the distal end 214 of the sheath hub 210 can be positioned against or proximate to the proximal end 312 of the outer sheath hub 310 such that the outer sheath engagement feature 250 can engage with the in-line sheath engagement feature 350 of the outer sheath hub 310 .

[0058] The catheter engagement feature 252 can be configured to frictionally engage a portion of the delivery catheter 102 to prevent or reduce distal and proximal translation and / or rotation of the delivery catheter 102 relative to the in-line sheath 200. The catheter engagement feature 252 can be triggered, activated, and / or engaged such that one or more portions thereof can frictionally contact a portion of the catheter shaft 130 extending through the sheath hub 210 after the distal portion 134 of the catheter shaft 130 is in a desired position distal to the expandable distal portion 234. In some instances, the delivery catheter 102 can be advanced relative to the in-line sheath 200 until the distal end 114 of the catheter hub 110 contacts the proximal end 212 of the sheath hub 210.

[0059] Figure 3A The arrows in the figure show the distal and proximal translation of the straight-through sheath 200 and the delivery catheter 102. For example, the top arrows show the distal and proximal translation of the straight-through sheath 200 relative to the outer expandable sheath 302. The bottom arrows show the distal and proximal translation of the delivery catheter 102 relative to the straight-through sheath 200. Figure 3B , the distal portion 134 of the catheter shaft 130 is shown as being disposed distally of the distal end 238 of the sheath shaft 230 . Figure 3C In more detail, Figure 3B In some cases, deploying the medical device may include translating the delivery catheter 102 distally relative to the in-line sheath 200 to advance the distal portion 134 of the catheter shaft 130 through the opening 240 at the distal end 238 of the sheath shaft 230. The distal wide portion of the medical device may then be advanced through the distal end 138 of the catheter shaft 130.

[0060] As described herein, after the expandable distal portion 234 is in a desired position distal to the distal end 338 of the outer sheath shaft 330, the outer sheath engagement feature 250 can engage with the push-in sheath engagement feature 350. The distal end 214 of the sheath hub 210 can be positioned against or proximate to the proximal end 312 of the outer sheath hub 310 such that the push-in sheath engagement feature 350 can engage with the outer sheath engagement feature 250 of the sheath hub 210. After the distal portion 134 of the catheter shaft 130 is in a desired position distal to the distal end 238 of the sheath shaft 230, the catheter engagement feature 252 can frictionally contact a portion of the catheter shaft 130 extending through the sheath hub 210.

[0061] Figure 3CShown in greater detail are the distal portion 134 of the catheter shaft 130 disposed distally of the distal end 238 of the sheath shaft 230, and the expandable distal portion 234 of the sheath shaft 230 disposed distally of the distal end 338 of the outer sheath shaft 330. A portion of the proximal portion 232 of the sheath shaft 230 may be positioned through the opening 340 at the distal end 338 of the outer sheath shaft 330, and another portion of the proximal portion 232 of the sheath shaft 230 may be disposed within the outer sheath shaft 330. A portion of the proximal portion 132 of the catheter shaft 130 may be positioned through the opening 240 at the distal end 238 of the sheath shaft 230, and another portion of the proximal portion 132 of the catheter shaft 130 may be disposed within the expandable distal portion 234 of the sheath shaft 230. When the distal portion 134 of the catheter shaft 130 is advanced distally away from the expandable distal portion 234 and a portion of the proximal portion 132 of the catheter shaft 130 is received by the expandable distal portion 234, a corresponding portion of the expandable distal portion 234 can assume a collapsed state. In some cases, the expandable distal portion 234 assuming a collapsed state can facilitate blood flow therearound, thereby providing improved blood flow to tissue during a procedure.

[0062] The medical device can be translated distally relative to the delivery catheter 102 and the in-line sheath 200 to advance the distal wide portion of the medical device out of the opening at the distal end 138 of the catheter shaft 130. For example, the distal wide portion of the medical device can be positioned distally of the distal portion 134 of the catheter shaft 130 at a target site, such as within a cardiac chamber including a ventricle.

[0063] The medical device can be retracted to be withdrawn from the target site. For example, the medical device can be translated proximally relative to the delivery catheter 102 to position the distal wide portion of the medical device back in the distal portion 134 of the catheter shaft 130. Then, the delivery catheter 102 can be translated proximally relative to the in-line sheath 200 to position the distal portion 134 of the catheter shaft 130 back in the expandable distal portion 234 of the sheath shaft 230. Then, the in-line sheath 200, the delivery catheter 102 and the medical device can be withdrawn together. When the in-line sheath 200, the delivery catheter 102 and the medical device are retracted by the outer expandable sheath 302, the distal wide portion of the medical device and the distal portion 134 of the catheter shaft 130 can be maintained in the expandable distal portion 234. For the deployment and retraction of the medical device, the distal portion 134 of the catheter shaft 130 and / or the distal wide portion of the medical device may not need to advance through the proximal portion 232 of the sheath shaft 230. The proximal portion 232 of the sheath shaft 230 can therefore have a reduced profile and / or include a different material than the material of the expandable distal portion 234 .

[0064] Figure 4 and Figure 5is a perspective view of an example of a sheath shaft including an expandable distal portion made of different materials, wherein the expandable distal portion is shown in an expanded state. Figure 4 An example of a sheath shaft 400 including an expandable distal portion 404 is shown, the expandable distal portion including an expandable coil 408. The expandable coil 408 can facilitate expansion and / or contraction of the expandable distal portion 404. The sheath shaft 400 can include a delivery catheter body 406 that extends through the sheath shaft 400 and is configured to receive at least a portion of a delivery catheter. The delivery catheter can be preloaded within the delivery catheter body 406 so that a distal portion of the catheter shaft of the delivery catheter can be disposed within the expandable distal portion 404 when the expandable distal portion 404 is in an expanded state, for example, preloaded within a portion of the delivery catheter body 406 that extends through the expandable distal portion 404. The expandable distal portion 404 can include a proximally directed portion 410 and a distally directed portion 412. In some cases, the proximally directed portion 410 can include a transition from the proximal portion 402 of the sheath shaft 400 to the expandable distal portion 404. For example, the transition portion can include a lateral cross-section that increases in a direction extending from the proximally oriented portion 410 to the distally oriented portion 412. The lateral cross-section can be perpendicular or substantially perpendicular to the longitudinal axis of the sheath shaft 400.

[0065] The expandable distal portion 404 may include an expandable coil 408 along a longitudinal portion. The expandable coil 408 may extend along at least a portion of the longitudinal dimension, including extending along the entire longitudinal dimension, such as the entire length of the expandable distal portion 404. The longitudinal dimension may extend along the longitudinal axis of the sheath shaft 400. In some cases, the coils of the expandable coil 408 may surround corresponding portions of the delivery catheter tube 406. For example, the expandable distal portion 404 may include an expandable coil 408, whose coils are positioned around a portion of the delivery catheter tube 406 of the expandable distal portion 404. In some cases, the coils of the expandable coil 408 positioned around the delivery catheter tube 406 may at least partially define the delivery catheter tube 406. In some cases, the expandable distal portion 404 including the expandable coil 408 may include a tubular configuration, including a cylindrical shape. For example, the coils of the expandable coil 408 may form the cylindrical shape of the expandable distal portion 404.

[0066] Figure 5An example of a sheath shaft 500 including an expandable distal portion 504 is shown, the expandable distal portion including a shape memory material 508 configured to facilitate expansion and / or contraction of the expandable distal portion 504. The expandable distal portion 504 is shown in an expanded state, for example when the distal portion of the catheter shaft of a delivery catheter is preloaded therein. The sheath shaft 500 may include a delivery catheter body 506 extending through the sheath shaft 500. For example, when the catheter shaft is preloaded within the delivery catheter body 506, the distal portion of the catheter shaft may be disposed within a portion of the delivery catheter body 506 extending through the expandable distal portion 504. At least a portion of the expandable distal portion 504 may include the shape memory material 508. The shape memory material 508 may be along at least a portion of the longitudinal dimension, including along the entire longitudinal dimension, such as the entire length of the expandable distal portion 504. The longitudinal dimension may extend along the longitudinal axis of the sheath shaft 500. Any number of shape memory materials may be used, including, for example, nitinol. In some cases, expandable distal portion 504 can include a tubular configuration, including a cylindrical shape. For example, expandable portion 504 including shape memory material 508 can be formed into a cylindrical shape.

[0067] The expandable distal portion 504 may include a proximally oriented portion 510 and a distally oriented portion 512. In some cases, the proximally oriented portion 510 may include a transition from the proximal portion 502 of the sheath shaft 500 to the expandable distal portion 504. For example, the transition may include a lateral cross-section that increases in a direction extending from the proximally oriented portion 510 to the distally oriented portion 512. The lateral cross-section may be perpendicular or substantially perpendicular to the longitudinal axis of the sheath shaft 500.

[0068] refer to Figure 4 and Figure 5 The described sheath shafts 400, 500 may include a proximal portion 402, 502 that may or may not include the same material as the corresponding expandable distal portion 404, 504. In some cases, reference Figure 4 The proximal portion 402 of the depicted sheath shaft 400 may include a different material than the expandable distal portion 404. In some cases, reference Figure 5 The proximal portion 502 of the depicted sheath shaft 500 may comprise the same material as the expandable distal portion 504 .

[0069] Figure 6600 includes a perspective view of an example of a sheath shaft 600 including an expandable distal portion 604, the expandable distal portion including a plurality of discrete elongated portions 608 disposed circumferentially around a delivery catheter body 606. The plurality of discrete elongated portions 608 can partially define a corresponding portion of the delivery catheter body 606, such as a portion of the delivery catheter body 606 extending through the expandable distal portion 604. The delivery catheter body 606 can be configured to slidably receive at least a portion of a catheter shaft of a delivery catheter. The plurality of discrete elongated portions 608 can be coupled to a proximal portion 602 of the sheath shaft 600. Each discrete elongated portion 608 can include a proximally directed end portion 610 and a distally directed end portion 612. The proximally directed portions 610 can be coupled to each other. For example, the proximally directed portion 610 can be coupled to the proximal portion 602 of the sheath shaft 600. In some cases, each discrete elongated portion of the plurality of discrete elongated portions 608 can extend distally from the proximal portion 602 , eg, the respective proximal end 614 of each discrete elongated portion 608 can be adjacent to the distal end of the proximal portion 602 .

[0070] Each of the plurality of discrete elongated portions 608 can be spaced apart from an adjacent discrete elongated portion 608 along at least a portion of the respective longitudinal dimension, thereby facilitating movement of a portion of the discrete elongated portion 608 away from the adjacent discrete elongated portion 608. The distally directed end portions 612 can be spaced apart from one another such that when the expandable distal portion 604 is in the expanded state, the distally directed end portions 612 can be configured to be disposed further away from one another than when the expandable distal portion 604 is in the collapsed state. In some cases, each of the plurality of discrete elongated portions 608 can be spaced apart from an adjacent discrete elongated portion 608 along the entire length of the respective discrete elongated portion 608. For example, each of the plurality of discrete elongated portions 608 can be rotated about its proximal end 614 to move away from and back toward an adjacent discrete elongated portion 608 such that the expandable distal portion 604 can be in an expanded state and a collapsed state, respectively. Each of the plurality of discrete elongated portions 608 can be rotated about its proximal end 614 to accommodate a distal portion of a catheter shaft positioned through the expandable distal portion 604 such that the distally directed end portions 612 of the discrete elongated portions 608 can be further away from adjacent distally directed end portions 612. Each of the plurality of discrete elongated portions 608 can be rotated toward each other while the distal portion of the catheter shaft is positioned distal to the expandable distal portion 604, e.g., positioning the distally directed end portions 612 closer to each other. In some instances, the expandable distal portion 604 can be in a collapsed state while the distal portion of the catheter shaft is positioned distal to the expandable distal portion 604. Figure 6The expandable distal portion 604 is shown in a collapsed state.

[0071] Reference again Figure 6 , each discrete elongated portion 608 may include a first portion 618 and a second portion 620, the second portion 620 being distal to the first portion 618. Each of the first portions 618 may have an angled orientation relative to the longitudinal axis of the sheath shaft 600. The first portion 618 may extend from the proximal portion 602 of the sheath shaft 600 at an angle relative to the longitudinal axis of the sheath shaft 600 to provide a transition from a smaller lateral cross-section of the proximal portion 602 to a larger lateral cross-section of the expandable distal portion 604. For example, the first portion 618 may include an inclined profile to provide a transition from a smaller lateral cross-section of the proximal portion 602 to a larger lateral cross-section of the expandable distal portion 604. In some cases, the second portion 620 may extend from the first portion 618 to the distal end 616 of the corresponding discrete elongated portion 608 along an axis parallel or substantially parallel to the longitudinal axis of the sheath shaft 600. The lateral cross-section of the sheath shaft 600 at the proximal end 614 of the discrete elongated portion 608 can be smaller than the lateral cross-section at the distal end 616 of the discrete elongated portion 608. For example, the inner diameter and / or outer diameter of the sheath shaft 600 at the proximal end 614 can be shorter than the inner diameter and / or outer diameter at the distal end 616.

[0072] although Figure 6 Four discrete elongated portions 608 are shown circumferentially disposed around the delivery catheter body 606, but it should be understood that the expandable distal portion may include fewer or more elongated portions. The discrete elongated portions may have any number of configurations. In some cases, the discrete elongated portions may have a rod configuration. In some cases, the discrete elongated portions may include one or more curved surface portions that at least partially define the delivery catheter body. For example, the discrete elongated portions may include a first surface that is oriented toward the delivery catheter body and extends along at least the longitudinal dimension of the expandable distal portion. The first surface may include a bend along a lateral dimension, for example, along a dimension that is perpendicular or substantially perpendicular to the longitudinal dimension, and is configured to at least partially define the delivery catheter body. In some cases, the bend may include a segment of a circle. In some cases, each discrete elongated portion may be identical. The discrete elongated portions may be evenly spaced around the delivery catheter body. For example, the expandable distal portion 604 may include four identical discrete elongated portions 608 extending distally from the proximal portion 602 and may be evenly spaced around the delivery catheter tube 606.

[0073] The proximal portion 602 and the expandable distal portion 604 may or may not include different materials. Figure 6A proximal portion 602 of a sheath shaft 600 is shown that includes a material that is different from the material of the expandable distal portion 604. For example, the proximal portion 602 including a first material can be attached, bonded, and / or assembled to the expandable distal portion 604. Alternatively, the sheath shaft 600 can be a unitary component. In some cases, the sheath shaft 600 can be a unitary unit that includes a consistent material throughout.

[0074] Fig. 7A is a side view of an example of a sheath shaft 700 having an expandable distal portion 704 including a plurality of discrete elongated portions 708 in a collapsed state, and Figure 7B is a side cross-sectional view of an example of a sheath shaft in an expanded state. Fig. 7A When in the collapsed state, each of the plurality of discrete elongated portions 708 can extend distally along an axis that is parallel or substantially parallel to the longitudinal axis of the sheath shaft 700. The plurality of discrete elongated portions 708 can be disposed circumferentially around the delivery catheter body 706 of the sheath shaft 700. Fig. 7A A catheter shaft disposed through the delivery catheter tube 706 is not shown. A plurality of discrete elongated portions 708 can be coupled to the proximal portion 702 of the sheath shaft 700. Each discrete elongated portion 708 can include a proximally directed end portion 710 and a distally directed end portion 712. The proximally directed portion 710 can be coupled to the proximal portion 702 of the sheath shaft 700. For example, each of the plurality of discrete elongated portions 708 can extend distally from the proximal portion 702 along an axis that is parallel or substantially parallel to the longitudinal axis of the sheath shaft 700.

[0075] When the expandable distal portion 704 is in the collapsed state, the expandable distal portion 704 can have a uniform or substantially uniform lateral cross-sectional area along the longitudinal dimension. The lateral cross-section can be perpendicular or substantially perpendicular to the longitudinal axis of the sheath shaft 700. The longitudinal dimension can be parallel or substantially parallel to the longitudinal axis of the sheath shaft 700. When in the collapsed state, the expandable distal portion 704 can have a cross-sectional size at the proximal end 714 that is the same or similar to the cross-sectional size at the distal end 716 of each of the plurality of discrete elongated portions 708. In some cases, the expandable distal portion 704 can have a uniform inner diameter and / or outer diameter along the longitudinal dimension, including the entire length of the expandable distal portion 704. For example, when in the collapsed state, the expandable distal portion 704 can have a uniform or substantially uniform inner diameter and / or outer diameter along the entire or substantially the entire length. The inner diameter and / or outer diameter at the proximal end 718 of the expandable distal portion 704 is the same as the inner diameter and / or outer diameter at the distal end 720 of the expandable distal portion 704 .

[0076] refer to Figure 7B, the expandable distal portion 704 is shown in an expanded state, and the distal portion 754 of the catheter shaft 750 is disposed through the expandable distal portion 704. For example, the catheter shaft 750 is disposed through the delivery catheter body 706 of the sheath shaft 700. The proximal portion 752 of the catheter shaft 750 is shown as being disposed within the proximal portion 702 of the sheath shaft 700. Each of the plurality of discrete elongated portions 708 can be rotated outwardly around a corresponding proximal end 714 in an expanded state to accommodate the distal portion 754 of the catheter shaft 750. When the expandable distal portion 704 is in an expanded state, the distal ends 716 of the plurality of elongated portions 708 can be spaced further apart from each other than when in a collapsed state. For example, the distal portion 754 of the catheter shaft 750 can be pushed against the proximally directed portion 710 of each of the plurality of discrete elongated portions 708, thereby rotating the plurality of discrete elongated portions 708 away from each other around their proximal ends 714. The proximal end 756 of the catheter shaft distal portion 754 can be close to or adjacent to the proximal end 714 of the discrete slender portion 708, and the distal end 758 of the catheter shaft distal portion 754 can be oriented toward the distal end 716 of the discrete slender portion 708.

[0077] In some cases, the catheter shaft 750 can be advanced relative to the sheath shaft 700 to deploy the catheter shaft 750. When the catheter shaft distal portion 754 is positioned distal to the distal end 720 of the expandable distal portion 704, the expandable distal portion 704 can assume a collapsed state.

[0078] Fig. 8A is a side view of an example of a sheath shaft 800 including a plurality of discrete elongated portions 808 in a collapsed state, and Figure 8B is a side cross-sectional view of an example of the sheath shaft in an expanded state. Fig. 8A, the sheath shaft 800 is shown in a collapsed state. Each discrete elongated portion 808 may include a proximally oriented end portion 810 and a distally oriented end portion 812. The proximally oriented portion 810 may include a bend 822 so that the lateral cross-section of the distal end 820 of the expandable distal portion 804 is greater than the lateral cross-section at the proximal end 818. The lateral cross-section may be taken along a plane perpendicular to or substantially perpendicular to the longitudinal axis of the sheath shaft 800. For example, a portion of each discrete elongated portion 808 proximal to the bend 822 may be angled relative to the longitudinal axis of the sheath shaft 800. In some cases, a portion of each discrete elongated portion 808 proximal to the bend 822 may be perpendicular to or substantially perpendicular to the longitudinal axis of the sheath shaft 800. In some cases, a portion of each discrete elongated portion 808 distal to the bend 822 may extend along an axis parallel to or substantially parallel to the longitudinal axis of the sheath shaft 800. The proximally oriented portion 810 can be coupled to the proximal portion 802 of the sheath shaft 800. In some cases, each discrete elongated portion 808 can extend distally from the proximal portion 802 along an "L-shaped" path. A portion of each discrete elongated portion 808 proximal to the bend 822 can form a shorter leg of the "L-shape", and a portion of each discrete elongated portion 808 distal to the bend 822 can form a longer leg of the "L-shape". In some cases, the bend 822 can include a stepped configuration. Multiple discrete elongated portions 808 can be arranged circumferentially around the delivery catheter body 806. The delivery catheter body 806 can be configured to slidably receive a catheter shaft 850, such as Figure 8B When the expandable distal portion 804 is in the collapsed state, the outer diameter and / or inner diameter at the proximal end 818 of the expandable distal portion 804 can be smaller than the outer diameter and / or inner diameter at the distal end 820 of the expandable distal portion 804. The outer diameter and / or inner diameter of the expandable distal portion 804 at the distal end 816 of the plurality of discrete elongated portions 808 can be larger than the outer diameter and / or inner diameter at the proximal end 814 of the plurality of discrete elongated portions 808.

[0079] refer to Figure 8B, the expandable distal portion 804 can be in an expanded state when the distal portion 854 of the catheter shaft 850 is received therein. The proximal portion 852 of the catheter shaft 850 can be received in the proximal portion 802 of the sheath shaft 800. For example, the proximal end 856 of the distal portion 854 can be disposed proximal to or adjacent to the bend 822 of the sheath shaft 800. In some cases, the proximal end 856 of the distal portion 854 can abut the bend 822, and the distal end 858 of the catheter shaft distal portion 854 can be oriented toward the distal end 816 of the discrete elongated portion 808. In some cases, contact between the proximally oriented end portion 810 of each of the plurality of discrete elongated portions 808, including the bend 822, and the catheter shaft distal portion 854 can cause the plurality of discrete elongated portions 808 to rotate outwardly about the respective proximal ends 814 to accommodate the catheter shaft distal portion 854.

[0080] In some cases, the catheter shaft 850 can be advanced relative to the sheath shaft 800 to deploy the catheter shaft 850. When the catheter shaft distal portion 854 is positioned distal to the distal end 820 of the expandable distal portion 804, the expandable distal portion 804 can assume a collapsed state.

[0081] In some cases, when in the expanded state, the expandable distal portion 804 described with reference to FIG8 can have a lateral cross-section at the distal end 820 that is smaller than the lateral cross-section at the distal end 720 of the expandable distal portion 704 described with reference to FIG7. In some cases, the bend 822 on the proximally directed portion 810 can provide a reduced lateral cross-sectional area. The reduced cross-sectional area can facilitate advancement of the sheath shaft 800 through the outer expandable sheath.

[0082] Fig. 9A is a side view of an example of a sheath shaft 900 in a collapsed state, wherein the sheath shaft 900 includes a plurality of discrete elongated portions 908 that each extend along a convexly curved path. Fig. 9B is a side cross-sectional view of the sheath shaft 900 in an expanded state. Fig. 9A , each discrete elongated portion 908 may include a proximally directed end portion 910 and a distally directed end portion 912. The delivery catheter body 906 may extend through the catheter shaft 900 and be configured to slidably receive the catheter shaft. A plurality of discrete elongated portions 908 may be circumferentially disposed around the delivery catheter body 906. Fig. 9ANot shown is a catheter shaft within the delivery catheter tube 906. Each discrete elongated portion 908 can extend along a convex curved path extending between a corresponding proximally directed end portion 910 and a distally directed end portion 912. In some instances, each discrete elongated portion 908 can extend along a convex curved path from a proximal end 914 to a distal end 916. Each of the plurality of discrete elongated portions 908 can be coupled to the proximal portion 902 of the sheath shaft 900, e.g., extending distally from the proximal portion 902 along a convex curved path to a distal end 916 of the corresponding discrete elongated portion 908.

[0083] refer to Fig. 9B , the catheter shaft 950 is received by the delivery catheter tube 906. For example, when the distal portion 954 of the catheter shaft 950 is received therein, the expandable distal portion 904 can be in an expanded state. The proximal portion 952 of the catheter shaft 950 can be received in the proximal portion 902 of the sheath shaft 900. The proximal end 956 of the distal portion 954 can be disposed proximal to or adjacent to the proximal end 918 of the expandable distal portion 904. The distal end 958 of the catheter shaft distal portion 954 can be oriented toward the distal end 920 of the expandable distal portion 904. In some cases, the proximal end 956 of the catheter shaft distal portion 954 can contact the proximally oriented end portions 910 of the plurality of discrete elongated portions 908. Contact between the proximally directed end portion 910 of each of the plurality of discrete elongated portions 908 and the distal portion 954 of the catheter shaft 950 can push the plurality of discrete elongated portions 908 outward, e.g., cause outward rotation about the respective proximal ends 914, so as to accommodate the distal portion 954 of the catheter shaft 950. In some instances, the convexly curved discrete elongated portions 908 can facilitate advancement of the sheath shaft 900 through the outer expandable sheath.

[0084] In some cases, the catheter shaft 950 can be advanced relative to the sheath shaft 900 to deploy the catheter shaft 950. When the catheter shaft distal portion 954 is positioned distal to the distal end 920 of the expandable distal portion 904, the expandable distal portion 904 can assume a collapsed state.

[0085] Fig. 10A is a side view of another example of a sheath shaft 1000 including a plurality of discrete elongated portions 1008 in a collapsed state, and Fig. 10B is a side cross-sectional view of another example of the sheath shaft in an expanded state. Fig. 10A, the sheath shaft 1000 is shown in a collapsed state. Each discrete elongated portion 1008 may include a proximally directed end portion 1010 and a distally directed end portion 1012. The delivery catheter body 1006 may extend through the catheter shaft 1000 and be configured to slidably receive the catheter shaft. Multiple discrete elongated portions 1008 may be circumferentially disposed around the delivery catheter body 1006. Fig. 10A The catheter shaft within the delivery catheter tube 1006 is not shown. The proximally directed portion 1010 may include a convex bend 1022 such that a lateral cross-section of the distally directed portion 1012 of the expandable distal portion 1004 is smaller than a lateral cross-section at the widest portion of the convex bend 1022. For example, the lateral cross-section at the distal end 1020 of the expandable distal portion 1004 can be smaller than a lateral cross-section at a proximal portion of the expandable distal portion 1004, such as at the widest portion of the convex bend 1022. The outer diameter and / or inner diameter of the proximal portion of the expandable distal portion 1004, such as at the widest portion of the convex bend 1022, can be larger than the outer diameter and / or inner diameter at the distal end 1016 of the plurality of discrete elongated portions 1008. In some cases, when the expandable distal portion 1004 is in the collapsed state, the distal end 1016 of each discrete elongated portion 1008 contacts at least one distal end 1016 of another discrete elongated portion 1008. In some cases, when the expandable distal portion 1004 is in the collapsed state, the distal ends 1016 of the plurality of discrete elongated portions 1008 can be spaced apart from one another.

[0086] refer to Fig. 10B, the expandable distal portion 1004 can be in an expanded state when the distal portion 1054 of the catheter shaft 1050 is received therein. The proximal portion 1052 of the catheter shaft 1050 can be received in the proximal portion 1002 of the sheath shaft 1000. The proximal end 1056 of the distal portion 1054 can be disposed proximal to or adjacent to the proximal end 1018 of the expandable distal portion 1004. The distal end 1058 of the catheter shaft distal portion 1054 can be oriented toward the distal end 1020 of the expandable distal portion 1004. The distal portion 1054 of the catheter shaft 1050 can be pushed against the plurality of discrete elongated portions 1008 such that, in the expanded state, the plurality of discrete elongated portions 1008 rotate outwardly about the respective proximal ends 1014 to accommodate the distal portion 1054 of the catheter shaft 1050. In some cases, the distal portion 1054 of the catheter shaft 1050 can be pushed against the proximally directed end portion 1010 and / or the distally directed end portion 1012. In some cases, when in the expanded state, the distally directed end portion 1012 can be in contact with the catheter shaft distal portion 1054 and disposed around the catheter shaft distal portion. In some cases, the contact between the catheter shaft distal portion 1054 and the distally directed end portion 1012 when the expandable distal portion 1004 is in the expanded state can facilitate the advancement of the sheath shaft 1000 through the outer expandable sheath. In some cases, the bend 1022 can conform to or substantially conform to a portion of the catheter shaft distal portion 1054. In some cases, the plurality of elongated portions 1008 can conform to or substantially conform to the shape of the catheter shaft distal portion 1054 to facilitate the passage of the expandable distal portion 1004 through the outer sheath shaft in the expanded state.

[0087] In some cases, the catheter shaft 1050 can be advanced relative to the sheath shaft 1000 to deploy the catheter shaft 1050. In some cases, the expandable distal portion 1004 can assume an intermediate expandable state when the catheter shaft distal portion 1054 is positioned distal to the distal end 1020 of the expandable distal portion 1004. For example, when the proximal portion 1052 of the catheter shaft 1050 is disposed through the expandable distal portion 1004, the distal end 1016 of each discrete elongated portion 1008 can contact a corresponding portion of the catheter shaft proximal portion 1052.

[0088] Fig.111 is a side perspective view of a sheath shaft 1100 including three sections, each section including a material different from the material of the other sections. The sheath shaft 1100 may include a proximal section 1102 and an expandable distal section 1104. When the expandable distal section 1104 is in an expanded state, the expandable distal section 1104 may include a lateral cross-section that is larger than the lateral cross-section of the proximal section 1102. For example, when the catheter shaft is preloaded within the delivery catheter tube 1106 of the sheath shaft 1100, the expandable distal section 1104 may be in the expanded state. Fig.11 The expandable distal portion 1104 is shown in an expanded state. The proximal portion 1102 may include a first portion 1108 and a second portion 1110, the first portion 1108 being more proximal than the second portion 1110. The first portion 1108 may include a material that is more rigid than the second portion 1110. In some cases, the first portion 1108 may include a rigid portion and the second portion 1110 may include a flexible portion. In some cases, the rigidity of the first portion 1108 may facilitate the desired torque capability of the sheath shaft 1100. The combination of the improved torque capability of the first portion 1108 and the flexibility of the second portion 1110 may facilitate the traversal of the sheath shaft 1100 through a tortuous anatomical path.

[0089] The first portion 1108 may include any number of materials to provide the desired rigidity. In some cases, the first portion 1108 may be braid-reinforced. The first portion may include a braid-reinforced tubular configuration. The second portion 1110 may include any number of materials to provide the desired flexibility. In some cases, the second portion 1110 may be braid- and / or coil-reinforced. In some cases, the second portion 1110 may include a braid- and / or coil-reinforced tubular configuration.

[0090] In some cases, the expandable distal portion 1104 can be coupled to the second portion 1110 of the proximal portion 1102. The expandable distal portion 1104 can be a portion that is both expandable and flexible. In some cases, the expandable distal portion 1104 can extend distally from the second portion 1110. For example, the expandable and flexible portion can extend distally from the flexible portion. The proximal end 1120 of the expandable distal portion 1104 can be adjacent to the distal end 1116 of the second portion 1110. The proximal end 1114 of the second portion 1110 can be adjacent to the distal end 1112 of the first portion 1108. The expandable distal portion 1104 can have one or more features as described herein. In some cases, the expandable distal portion 1104 can be coil-enhanced. For example, the expandable distal portion 1104 can include an expandable coil 1118 extending from the proximal end 1120 to the distal end 1122.

[0091] Alternatively, the sheath shaft 1100 can include a non-expandable distal portion. For example, the sheath shaft 1100 can include a non-expandable distal portion having, for example, a larger lateral cross-section than the proximal portion 1102 of the sheath shaft 1100. The non-expandable distal portion can have the same configuration as the expandable distal portion 1104 in the expanded state. The non-expandable distal portion can include a flexible material. In some cases, the non-expandable distal portion can be a flexible portion that includes the same size and shape as the size (including cross-sectional size) and shape of the expandable distal portion 1104 in the expanded state.

[0092] refer to Figure 4 , 5 , 6, 7, 8, 9, 10 and 11 described sheath shafts 400, 500, 600, 700, 800, 900, 1000, 1100 may have one or more other features of the sheath shaft 230 described with reference to FIG. 2. In some cases, reference Figure 4 , 5 , 6, 7, 8, 9, 10 and 11 described sheath shafts 400, 500, 600, 700, 800, 900, 1000, 1100 may be part of one or more medical device delivery systems described herein (including the medical device delivery system 100 described with reference to FIG. 2).

[0093] Fig.12 and Fig.13 is a side cross-sectional view illustrating a distal end of an example expandable distal portion, wherein the distal end can be configured to mate with a distal portion of a medical device received by a corresponding expandable distal portion. Fig.12 An expandable distal portion 1200 is shown including a circumferential tapered portion 1202 at a distal end 1204. The expandable distal portion 1200 can be part of a push-in sheath including one or more other features as described herein. For simplicity, the remainder of the push-in sheath is not shown. Fig.12, the circumferential tapered portion 1202 may extend circumferentially around the distal end 1204 of the expandable distal portion 1200. The circumferential tapered portion 1202 may have a slope and / or curvature oriented toward the longitudinal axis of the expandable distal portion 1200. The circumferential tapered portion 1202 may be configured to engage with a corresponding portion of the medical device 1250 when the medical device 1250 is preloaded in the in-line sheath. For example, when the medical device 1250 is preloaded in the in-line sheath, the medical device 1250 may include a distal portion 1252 disposed distal to the distal end 1204 of the expandable distal portion 1200. The medical device 1250 may be preloaded in a delivery catheter preloaded in the in-line sheath such that the distal portion 1252 of the medical device 1250 is distal to the distal end of the delivery catheter, such as the distal end of a catheter shaft of the delivery catheter. For simplicity, the delivery catheter is not shown.

[0094] The circumferential tapered portion 1202 can be seated against a corresponding tapered portion 1254 of the medical device 1250. The corresponding tapered portion 1254 can have a configuration that is the same or similar to that of the circumferential tapered portion 1202, including, for example, a same or similar slope and / or curvature. In some cases, the corresponding tapered portion 1254 can be on a proximally oriented surface of the distal portion 1252, such that the corresponding tapered portion 1254 can mate with the circumferential tapered portion 1202 when the medical device 1250 is preloaded in the in-line sheath. In some cases, the corresponding tapered portion 1254 can be a curved portion, such that the circumferential tapered portion 1202 can be configured to mate with a curved portion of the medical device 1250 disposed distal to the expandable distal portion 1200.

[0095] refer to Fig.13, the expandable distal portion 1300 has a distal end 1304, the distal end including a circumferential lateral portion 1302 configured to engage with a corresponding portion of a medical device 1350. The expandable distal portion 1300 can be part of a straight-through sheath including one or more other features as described herein. For simplicity, the remainder of the straight-through sheath is not shown. The circumferential lateral portion 1302 can extend circumferentially around the distal end 1304 of the expandable distal portion 1300. The circumferential lateral portion 1302 can include a surface that is perpendicular or substantially perpendicular to the longitudinal axis of the expandable distal portion 1300. The circumferential lateral portion 1302 is configured to engage with a corresponding lateral portion 1354 of a medical device 1350 disposed distal to the expandable distal portion 1300. For example, the distal portion 1352 of the medical device 1350 can be disposed distal to the distal end 1304 of the expandable distal portion 1300. In some cases, the circumferential lateral portion 1302 can include a proximally-oriented portion of the distal portion 1352 of the medical device 1350 that is perpendicular or substantially perpendicular to the longitudinal axis of the expandable distal portion 1300. For example, a proximally-oriented flat portion of the medical device 1350 disposed distal to the distal end 1304 of the expandable distal portion 1300 can seat against the circumferential lateral portion 1302.

[0096] The engagement between the distal portion of the medical device and the distal end of the sheath shaft can facilitate secure positioning of the medical device within the delivery catheter and / or in-line sheath during advancement of the medical delivery system through the outer expandable sheath. Fig.12 and 13 The expandable distal portions 1200, 1300 described may be part of one or more sheath shafts described herein, including, for example, with reference to Figure 4 , 5 and 11 described sheath shafts 400 , 500 and 1100 .

[0097] Fig.14 1400 is a process flow diagram of an example of a process 1400 for delivering a medical device using one or more medical delivery systems in a medical delivery system as described herein. In box 1402, the process may involve providing an outer expandable sheath. The outer expandable sheath may include an outer sheath hub and an outer sheath shaft. In some cases, the outer expandable sheath may be positioned in an anatomical path to facilitate subsequent positioning of the medical device through the outer expandable sheath. In some cases, the outer expandable sheath may be an introducer pathway sheath. The outer sheath shaft may include at least a portion of the outer sheath shaft, the portion being expandable and configured to be in a collapsed state before the medical device delivery system is inserted through the outer sheath shaft, and in an expanded state to accommodate the medical device delivery system when the medical device delivery system is positioned to pass through the outer sheath shaft.

[0098] In frame 1404, the process may involve providing a delivery catheter. The medical device may be preloaded in the delivery catheter. The delivery catheter may include a catheter shaft including a proximal portion that slidably receives a proximal narrow portion of the medical device. The distal portion of the catheter shaft may slidably receive a distal wide portion of the medical device. The distal wide portion of the medical device may have a lateral cross-sectional area greater than the lateral cross-sectional area of ​​the proximal narrow portion of the medical device. For example, the inner diameter and / or outer diameter of the distal wide portion may be greater than the inner diameter and / or outer diameter of the proximal narrow portion. In some cases, the distal portion of the catheter shaft may have a lateral cross-sectional area greater than the lateral cross-sectional area of ​​the proximal portion of the catheter shaft to receive the corresponding portion of the medical device. For example, the inner diameter and / or outer diameter of the distal portion of the catheter shaft may be greater than the inner diameter and / or outer diameter of the proximal portion of the catheter shaft.

[0099] In block 1406, the process can involve providing a push-in sheath including a sheath shaft, at least a portion of a catheter shaft being preloaded within the sheath shaft. The sheath shaft can include a proximal portion that slidably receives the proximal portion of the catheter shaft. The expandable distal portion of the sheath shaft in an expanded state can slidably receive the distal portion of the catheter shaft.

[0100] In frame 1408, the process can involve advancing the expandable distal portion of the sheath shaft in the expanded state through the outer expandable sheath. The delivery catheter can be preloaded in the in-line sheath so that when the expandable distal portion of the sheath shaft is advanced through the outer expandable sheath, at least a portion of the catheter shaft is carried by the sheath shaft. For example, at least a portion of the sheath shaft including the expandable distal portion can be advanced through the outer sheath hub and the outer sheath shaft. The in-line sheath can be translated distally relative to the outer expandable sheath until the expandable distal portion is advanced through the opening at the distal end of the outer sheath shaft and is disposed distal to the distal end of the outer sheath shaft.

[0101] When the sheath shaft is translated distally relative to the outer expandable sheath and advances through the outer sheath hub and the outer sheath shaft, the sheath shaft can protect the catheter shaft and the medical device preloaded therein. For example, the outer sheath hub may include one or more seals, including a hemostatic seal. When the sheath shaft advances through the one or more seals, the sheath shaft can provide column strength along the longitudinal dimension of the sheath shaft. The sheath shaft can protect the catheter sheath and the medical device from interacting with one or more seals of the outer sheath hub. As described herein, the outer sheath shaft may include at least a portion that is in a collapsed state prior to insertion into the delivery system. When the sheath shaft advances through the collapsed outer sheath shaft, the sheath shaft can provide column strength and / or protection for the catheter sheath and the medical device.

[0102] In frame 1410, the process can involve advancing the delivery catheter relative to the in-line sheath to position the distal portion of the catheter shaft at the distal end of the expandable distal portion of the sheath shaft. For example, the delivery catheter can be translated distally relative to the in-line sheath to advance the distal portion of the catheter shaft through the distal opening on the distal end of the sheath shaft, so that the deployment of the medical device. After the expandable distal portion of the sheath shaft is positioned at the distal end of the outer sheath shaft, the distal portion of the catheter shaft can be positioned to pass through the distal opening on the distal end of the sheath shaft. In some cases, for example, when a part of the proximal portion of the catheter shaft is received by the expandable distal portion, the expandable distal portion of the sheath shaft can present a collapsed state after the distal portion of the catheter shaft advances and leaves the expandable distal portion. As described herein, the proximal portion of the catheter shaft can have a smaller lateral cross-sectional size compared to the distal portion of the catheter shaft.

[0103] In block 1412, the process can involve advancing the medical device relative to the delivery catheter to position the distal wide portion of the medical device distal to the distal end of the catheter shaft. In some cases, after the distal portion of the catheter shaft is positioned distal to the distal end of the sheath shaft, the medical device can be deployed from the delivery catheter.

[0104] In some cases, the outer expandable sheath can be inserted through an opening in the iliac artery or the femoral artery. A straight-insert sheath comprising a delivery catheter and a medical device preloaded therein can advance through the outer expandable sheath, and when the straight-insert sheath is positioned to pass through the outer expandable sheath, the corresponding portion of the outer expandable sheath presents an expanded state. When the sheath shaft advances through the outer expandable sheath, the expandable distal portion of the sheath shaft can be in an expanded state. The expandable distal portion of the sheath shaft can be positioned distal to the distal end of the outer expandable sheath and enter a target anatomical structure, such as the aorta, including the descending aorta or the abdominal aorta. After the expandable distal portion of the sheath shaft advances and leaves the outer expandable sheath, the outer expandable sheath can present a collapsed state, so as to facilitate blood flow around the outer expandable sheath. The outer expandable sheath in a collapsed state can facilitate blood flow close to and / or adjacent to the insertion site, such as an area with narrower blood vessels, such as the iliac artery or the femoral artery.

[0105] After the expandable distal portion of the sheath shaft is in its target position, the delivery catheter and / or medical device can then be advanced to the target site. The delivery catheter can be translated distally relative to the in-line sheath to deploy the distal portion of the catheter sheath from the expandable distal portion of the sheath shaft. Subsequently, the distal wide portion of the medical device can be deployed from the delivery catheter. As described herein, the expandable distal portion of the sheath shaft can be positioned in a larger vessel that can more easily accommodate the expandable distal portion. After the distal portion of the catheter sheath carrying the distal wide portion of the medical device therein advances and leaves the distal end of the expandable distal portion, the expandable distal portion of the sheath shaft can be in a collapsed state. The collapsed expandable distal portion can facilitate blood flow around it, for example, in the descending aorta or the abdominal aorta.

[0106] The medical device can be used to treat any number of conditions. In some cases, the medical device can be configured to treat heart disease. In some cases, the distal wide portion of the medical device can be advanced to a target site in a heart chamber, including the right ventricle or the left ventricle.

[0107] In some cases, the catheter engagement feature of the sheath hub can be activated to provide frictional contact between the in-line sheath and the delivery catheter to prevent or reduce proximal translation and distal translation of the delivery catheter relative to the in-line sheath. For example, after the distal portion of the catheter shaft advances and leaves the distal end of the sheath shaft and is positioned at the desired position, the relative position of the delivery catheter and the in-line sheath can be fixed. The frictional contact between the engagement feature of the sheath hub and the delivery catheter can prevent or reduce the translation and / or rotational movement of the delivery catheter relative to the in-line sheath. In some cases, after the relative position of the delivery catheter and the in-line sheath is fixed, the medical device can advance and leave the distal end of the catheter shaft.

[0108] In some cases, an outer sheath engagement feature of a sheath hub configured to engage with the hub of an outer expandable sheath can be activated to prevent or reduce distal and proximal translation of the in-line sheath relative to the outer expandable sheath. For example, after the expandable distal portion of the sheath shaft advances to leave the distal end of the outer sheath shaft and is positioned at a desired position, the relative position of the in-line sheath and the outer expandable sheath can be fixed. In some cases, the distal portion of the catheter shaft can advance to leave the distal end of the sheath shaft after the relative position of the outer expandable sheath and the in-line sheath is fixed.

[0109] Fig.151 is a process flow diagram illustrating a manufacturing process 1500 for manufacturing one or more medical device delivery systems as described herein. In box 1502, the process may involve providing a medical device including a proximal narrow portion and a distal wide portion. In box 1504, the process may involve providing a catheter shaft of a delivery catheter. The catheter shaft of the delivery catheter may be disposed around at least a portion of the medical device so that the proximal portion of the catheter shaft slidably receives at least a portion of the proximal narrow portion of the medical device. The distal portion of the catheter shaft may slidably receive the distal wide portion of the medical device. In box 1506, the process may involve providing a sheath shaft of an in-line sheath. The sheath shaft may surround at least a portion of the catheter shaft. The proximal portion of the sheath shaft may slidably receive at least a portion of the proximal portion of the catheter shaft, and the expandable distal portion of the sheath shaft in an expanded state slidably receives the distal portion of the catheter shaft. As described herein, in some cases, the expandable distal portion may include a tubular configuration, including a cylindrical configuration. Alternatively or in combination, the expandable distal portion may include a plurality of discrete elongated portions.The plurality of discrete elongated portions may be disposed circumferentially around the distal portion of the catheter shaft.

[0110] In some cases, the in-line sheath and delivery catheter can be assembled together. In some cases, the catheter hub can be coupled to the catheter shaft and / or the sheath hub can be coupled to the sheath shaft after the sheath shaft is disposed around at least a portion of the catheter shaft. For example, the catheter hub can be coupled to a proximal portion of the catheter sheath and / or the sheath hub can be coupled to a proximal portion of the sheath shaft after the sheath shaft is positioned around at least a portion of the catheter shaft.

[0111] Additional description of the example

[0112] A list of examples is provided below, each of which may include aspects of any other examples disclosed herein. In addition, aspects of any of the above examples may be implemented in any of the numbered examples provided below.

[0113] Example 1: A medical device delivery system comprising a delivery catheter and an in-line sheath. The delivery catheter may include a catheter hub and a catheter shaft. The catheter shaft may include a medical device catheter extending through the catheter shaft and configured to slidably receive at least a portion of a medical device, wherein a proximal portion of the catheter shaft extends distally from the catheter hub and is configured to slidably receive a proximal narrow portion of the medical device, and wherein the distal portion of the catheter shaft is configured to slidably receive a distal wide portion of the medical device, and wherein the distal wide portion of the medical device has a diameter wider than a diameter of a proximal narrow portion of the medical device. The delivery catheter may be preloaded in an in-line sheath. The in-line sheath may include a sheath hub and a sheath shaft, the sheath shaft including a delivery catheter body extending through the sheath shaft and configured to slidably receive at least a portion of the catheter shaft. The proximal portion of the sheath shaft may extend distally from the sheath hub and slidably receive at least a portion of the proximal portion of the catheter shaft, and the expandable distal portion of the sheath shaft may be configured to assume an expanded state or a collapsed state, and wherein the expandable distal portion is configured to slidably receive the distal portion of the catheter shaft when in its expanded state.

[0114] Example 2: A system according to any example herein, in particular example 1, wherein the expandable distal portion of the sheath shaft comprises a tubular configuration.

[0115] Example 3: The system according to any example herein, in particular example 2, wherein the expandable distal portion comprises a cylindrical shape when in the expanded state.

[0116] Example 4: A system according to any example herein, in particular examples 2 or 3, wherein the expandable coil extends along a longitudinal portion of the expandable distal portion, the coils of the expandable coil extending around a corresponding portion of the delivery catheter body.

[0117] Example 5: A system according to any example herein, in particular examples 2 to 4, wherein the expandable distal portion comprises a shape memory material.

[0118] Example 6: A system according to any example herein, in particular examples 2 to 5, wherein the distal end of the expandable distal portion includes a circumferential tapered portion having an inclined surface oriented toward the longitudinal axis of the sheath shaft, the circumferential tapered portion being configured to engage with a curved portion of the medical device disposed distal to the expandable distal portion.

[0119] Example 7: A system according to any example herein, in particular examples 2 to 5, wherein the distal end of the expandable distal portion includes a circumferential lateral portion perpendicular to the longitudinal axis of the sheath shaft, and the circumferential lateral portion is configured to engage with a flat portion of the medical device disposed distal to the expandable distal portion.

[0120] Example 8: A system according to any example herein, in particular Example 1, wherein the expandable distal portion includes a plurality of discrete slender portions, the plurality of discrete slender portions being circumferentially arranged around the delivery catheter body and partially defining a corresponding portion of the delivery catheter body, each discrete slender portion including a proximally directed end portion and a distally directed end portion, the proximally directed portions being connected to each other, and the distally directed end portions being spaced apart from each other, wherein when the expandable distal portion is in the expanded state, the distally directed end portions are configured to be disposed farther away from each other than when the expandable distal portion is in the collapsed state.

[0121] Example 9: A system according to any example herein, in particular example 8, wherein the expandable distal portion comprises three discrete elongated portions.

[0122] Example 10: A system according to any example herein, in particular example 8 or 9, wherein when the expandable distal portion is in the collapsed state, each discrete slender portion extends distally along an axis parallel to the longitudinal axis of the sheath axis to provide an expandable distal portion having a consistent outer diameter along the longitudinal dimension of the expandable distal portion.

[0123] Example 11: A system according to any example herein, in particular example 8 or 9, wherein each discrete elongated portion extends along a convex curved path from a corresponding proximal end to a corresponding distal end.

[0124] Example 12: A system according to any example herein, in particular example 8 or 9, wherein when the expandable distal portion is in the collapsed state, the proximally oriented portion of each discrete slender portion includes a bend to provide an outer diameter of the expandable distal portion at the distal end of the plurality of discrete slender portions, the outer diameter being larger than the outer diameter at the proximal end of the plurality of discrete slender portions.

[0125] Example 13: A system according to any example herein, in particular examples 8 or 9, wherein the proximally directed portion of each discrete slender portion includes a convex bend to provide a proximal portion of the expandable distal portion having an outer diameter wider than an outer diameter of the distal portion of the expandable distal portion.

[0126] Example 14: A system according to any example herein, in particular example 13, wherein when the expandable distal portion is in the collapsed state, the distal end of each discrete slender portion is in contact with at least one other discrete slender portion.

[0127] Example 15: A system according to any example herein, in particular example 13, wherein when the expandable distal portion is in the collapsed state, the distal ends of the plurality of discrete elongated portions are spaced apart from one another.

[0128] Example 16: The system according to any example herein, in particular examples 1 to 15, wherein the proximal portion of the sheath shaft comprises a rigid portion and a flexible portion, the rigid portion being proximal to the flexible portion.

[0129] Example 17: A system according to any example herein, in particular Example 16, wherein the expandable distal portion extends distally from the flexible portion.

[0130] Example 18: A system according to any example herein, in particular examples 1 to 17, wherein the sheath hub includes a catheter engagement feature, which is configured to engage with a portion of the delivery catheter to prevent distal and proximal translation of the delivery catheter relative to the in-line sheath.

[0131] Example 19: The system of any example herein, in particular Example 18, wherein the catheter engagement feature comprises a catheter shaft engagement component configured to frictionally contact a portion of the catheter shaft.

[0132] Example 20: A system according to any example herein, in particular examples 1 to 19, wherein the expandable distal portion of the sheath shaft and at least a portion of the proximal portion of the sheath shaft are configured to advance through an outer expandable sheath; and the sheath hub includes an outer sheath engagement feature, which is configured to engage with the outer expandable sheath to prevent distal and proximal translation of the insert sheath relative to the outer expandable sheath.

[0133] Example 21: The system according to any example herein, in particular Example 20, wherein the outer sheath engagement feature includes a hub engagement member configured to engage with a hub of the outer expandable sheath.

[0134] Example 22: A method of delivering a medical device, the method comprising providing an outer expandable sheath; providing a delivery catheter, the delivery catheter comprising a catheter shaft, the catheter shaft having a proximal portion that slidably receives a proximal narrow portion of the medical device and a distal portion that slidably receives a distal wide portion of the medical device; and providing a push-through sheath comprising a sheath shaft, at least a portion of the catheter shaft being preloaded within the sheath shaft. The sheath shaft may include a proximal portion that slidably receives the proximal portion of the catheter shaft, and an expandable distal portion that slidably receives the distal portion of the catheter shaft in an expanded state. The method may include advancing the expandable distal portion of the sheath shaft in the expanded state through the outer expandable sheath; advancing the delivery catheter relative to the push-through sheath to position the distal portion of the catheter shaft distal to the distal end of the expandable distal portion of the sheath shaft; and advancing the medical device relative to the delivery catheter to position the distal wide portion of the medical device distal to the distal end of the catheter shaft.

[0135] Example 23: The method according to any example herein, in particular Example 22, and further comprising advancing the distal wide portion of the medical device into a heart chamber.

[0136] Example 24: A method according to any example herein, in particular examples 22 or 23, and further comprising activating a catheter engagement feature of a sheath hub of a straight-through sheath to provide frictional contact between the straight-through sheath and the delivery catheter to prevent proximal and distal translation of the delivery catheter relative to the straight-through sheath.

[0137] Example 25: A method according to any example herein, in particular examples 22 to 24, and further comprising activating an outer sheath engagement feature of a sheath hub of the insert sheath to engage with the hub of the outer expandable sheath to prevent distal and proximal translation of the insert sheath relative to the outer expandable sheath.

[0138] The above methods may be performed on a living animal or on a simulated object, such as a cadaver, a cadaver heart, an anthropomorphic artifact, a simulator (eg, having simulated body parts, hearts, tissues, etc.).

[0139] Example 26: A method for manufacturing a medical device delivery system, the method comprising providing a medical device, the medical device comprising a proximal narrow portion and a distal wide portion; providing a catheter shaft of a delivery catheter, the proximal portion of the catheter shaft slidably receiving at least a portion of the proximal narrow portion of the medical device, and the distal portion of the catheter shaft slidably receiving the distal wide portion of the medical device; and providing a sheath shaft of a straight-in sheath, the proximal portion of the sheath shaft slidably receiving at least a portion of the proximal portion of the catheter shaft, and the expandable distal portion of the sheath shaft in an expanded state slidably receiving the distal portion of the catheter shaft.

[0140] Example 27: The method according to any example herein, in particular Example 26, and further comprising providing a catheter hub, and coupling the catheter hub to the proximal portion of the catheter sheath.

[0141] Example 28: The method according to any example herein, in particular example 26 or 27, and further comprising providing a sheath hub, and coupling the sheath hub to the proximal portion of the sheath shaft.

[0142] Example 29: The method according to any example herein, in particular examples 26 to 28, wherein providing a sheath shaft of the push-in sheath around at least a portion of the catheter shaft comprises providing an expandable distal portion comprising a tubular configuration.

[0143] Example 30: A method according to any example herein, in particular examples 26 to 28, wherein the sheath shaft providing a straight-through sheath around at least a portion of the catheter shaft includes providing an expandable distal portion, the expandable distal portion comprising a plurality of discrete elongated portions circumferentially arranged around the distal portion of the catheter shaft.

[0144] The above methods may be performed on a living animal or on a simulated object, such as a cadaver, a cadaver heart, an anthropomorphic artifact, a simulator (eg, having simulated body parts, hearts, tissues, etc.).

[0145] Depending on the example, some actions, events or functions of any process or algorithm described in this article may be performed in a different order, may be added, combined or omitted entirely. Therefore, in some instances, not all described actions or events are necessary to practice the process.

[0146] Conditional language used herein, such as "may", "can", "could", "might", "for example", etc., unless otherwise expressly stated or otherwise understood in the context of use, is generally intended and generally intended to express that certain instances include certain features, elements and / or steps, while other instances do not include certain features, elements and / or steps. Therefore, such conditional language is generally not intended to imply that features, elements and / or steps are required for one or more instances in any case, or that one or more instances must include logic for determining whether these features, elements and / or steps are included in any particular instance or will be performed in any particular instance with or without author input or prompting. The terms "include", "comprise", "have", etc. are synonyms, used in their ordinary sense, and are used inclusively in an open-ended manner, and do not exclude additional elements, features, actions, operations, etc. In addition, the term "or" is used in a non-exclusive sense (and is not used in an exclusive sense), so that when, for example, a list of connected elements is used, the term "or" means one, some, or all of the elements in the list. Unless specifically stated otherwise, linking language such as the phrase "at least one of X, Y, and Z" is generally understood in context to convey that an item, term, element, etc. can be X, Y, or Z. Thus, such linking language is generally not intended to imply that certain examples require that at least one of X, at least one of Y, and at least one of Z each be present.

[0147] It should be understood that in the above description of examples, various features are sometimes combined in a single example, figure or its specification for the purpose of simplifying the present disclosure and helping to understand one or more of the various inventive aspects. However, this method of the present disclosure should not be interpreted as reflecting the intention that any claim requires more features than the features clearly recorded in the claim. In addition, any parts, features or steps shown and / or described in the specific examples herein can be applied to any other example or used with any other example. In addition, for each example, no component, feature, step or group of components, features or steps is necessary or indispensable. Therefore, it is expected that the scope of the present invention disclosed herein and claimed below should not be limited by the specific examples described above, but should only be determined by clearly reading the attached claims.

[0148] It should be understood that certain ordinal terms (such as "first" or "second") may be provided for ease of reference and do not necessarily imply physical characteristics or order. Therefore, as used herein, ordinal terms (such as "first", "second", "third", etc.) used to modify elements (such as structures, components, operations, etc.) do not necessarily indicate the priority or order of the elements relative to any other elements, but can generally distinguish the elements from another element with a similar or identical name (but using ordinal terms). In addition, as used herein, indefinite articles ("one" and "an") can indicate "one or more" instead of "one". In addition, operations performed "based on" a condition or event can also be performed based on one or more other conditions or events that are not explicitly stated.

[0149] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the examples belong. It should also be understood that, unless expressly defined as such herein, terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their context in the relevant art and the present invention, and will not be interpreted in an idealized or overly formal sense.

[0150] Spatially relative terms "external," "internal," "upper," "lower," "below," "above," "vertical," "horizontal," and similar terms may be used herein to describe the relationship between one element or component and another element or component, as shown in the figures. It should be understood that the spatially relative terms are intended to cover different orientations of the device in use or operation in addition to the orientations described in the drawings. For example, in the case where the device shown in the figures is flipped, a device positioned "below" or "below" another device can be placed "above" the other device. Thus, the illustrative term "below" can include a lower position and an upper position. The device can also be oriented in another direction, and thus the spatially relative terms can be interpreted differently depending on the direction.

[0151] Unless expressly stated otherwise, comparative and / or quantitative terms such as "less", "more", "greater", etc. are intended to encompass the concept of equality. For example, "less" may not only mean "less" in the strictest mathematical sense, but also mean "less than or equal to".

Claims

1. A medical device delivery system, comprising: A delivery catheter, the delivery catheter comprising: a catheter hub; and a catheter shaft including a medical device conduit extending therethrough and configured to slidably receive at least a portion of a medical device, wherein the proximal portion of the catheter shaft extends distally from the catheter hub and is configured to slidably receive the proximal narrow portion of the medical device, and wherein the distal portion of the catheter shaft is configured to slidably receive a distal wide portion of the medical device, and wherein the distal wide portion of the medical device has a diameter wider than a diameter of a proximal narrow portion of the medical device; and A straight-insertion sheath, wherein the delivery catheter is preloaded in the straight-insertion sheath, and the straight-insertion sheath comprises: a sheath hub; and A sheath shaft comprising a delivery catheter body extending through the sheath shaft and configured to slidably receive at least a portion of the catheter shaft, wherein a proximal portion of the sheath shaft extends distally from the sheath hub and is configured to slidably receive at least a portion of the proximal portion of the catheter shaft, and wherein the expandable distal portion of the sheath shaft is configured to assume an expanded state or a collapsed state, and wherein the expandable distal portion of the sheath shaft is configured to slidably receive the distal portion of the catheter shaft when in its expanded state.

2. The system of claim 1, wherein the expandable distal portion of the sheath shaft comprises a tubular configuration.

3. The system of claim 2, wherein the expandable distal portion comprises a cylindrical shape when in the expanded state.

4. A system according to claim 2 or 3, wherein the expandable coil extends along a longitudinal portion of the expandable distal portion, and the coils of the expandable coil extend around a corresponding portion of the delivery catheter body.

5. The system of claim 2 or 3, wherein the expandable distal portion comprises a shape memory material.

6. A system according to claim 2 or 3, wherein the distal end of the expandable distal portion includes a circumferential tapered portion having an inclined surface oriented toward the longitudinal axis of the sheath shaft, and the circumferential tapered portion is configured to engage with a curved portion of the medical device disposed distal to the expandable distal portion.

7. A system according to claim 2 or 3, wherein the distal end of the expandable distal portion includes a circumferential lateral portion perpendicular to the longitudinal axis of the sheath shaft, and the circumferential lateral portion is configured to engage with a flat portion of the medical device disposed distal to the expandable distal portion.

8. The system of claim 1, wherein the expandable distal portion comprises: a plurality of discrete elongated sections disposed circumferentially about the delivery catheter body and partially defining a corresponding portion of the delivery catheter body, each discrete elongated section including a proximally directed end portion and a distally directed end portion, the proximally directed portions being coupled to one another and the distally directed end portions being spaced apart from one another, Wherein when the expandable distal portion is in the expanded state, the distally directed end portions are configured to be disposed farther apart from each other than when the expandable distal portion is in the collapsed state.

9. A system according to claim 8, wherein when the expandable distal portion is in the collapsed state, each discrete slender portion extends distally along an axis parallel to the longitudinal axis of the sheath axis to provide an expandable distal portion having a consistent outer diameter along the longitudinal dimension of the expandable distal portion.

10. The system of claim 8, wherein each discrete elongated portion extends along a convexly curved path from a corresponding proximal end to a corresponding distal end.

11. A system according to claim 8, wherein when the expandable distal portion is in the collapsed state, the proximally oriented portion of each discrete slender portion includes a bend to provide an outer diameter of the expandable distal portion at the distal end of the plurality of discrete slender portions, the outer diameter being larger than the outer diameter at the proximal end of the plurality of discrete slender portions.

12. The system of claim 8, wherein the proximally directed portion of each discrete elongated portion includes a convex curvature to provide a proximal portion of the expandable distal portion including an outer diameter wider than an outer diameter of a distal portion of the expandable distal portion.

13. A system according to claim 12, wherein when the expandable distal portion is in the collapsed state, the distal end of each discrete slender portion is in contact with at least one other discrete slender portion, or the distal ends of the multiple discrete slender portions are spaced apart from each other.

14. A system according to claim 2, 3 or any one of claims 8 to 13, wherein the proximal portion of the sheath shaft includes a rigid portion and a flexible portion, the rigid portion is proximal to the flexible portion, and wherein the expandable distal portion extends distally from the flexible portion.

15. A system according to claim 2, 3 or any one of claims 8 to 13, wherein the sheath hub includes a catheter engagement feature, which is configured to frictionally contact a portion of the delivery catheter to prevent distal and proximal translation of the delivery catheter relative to the straight-insert sheath.

16. A system according to claim 2, 3 or any one of claims 8 to 13, wherein: the expandable distal portion of the sheath shaft and at least a portion of the proximal portion of the sheath shaft being configured to be advanced through an outer expandable sheath; and The sheath hub includes an outer sheath engagement feature configured to engage with a hub of the outer expandable sheath to prevent distal and proximal translation of the in-line sheath relative to the outer expandable sheath.

17. A method of delivering a medical device, the method comprising: providing an outer expandable sheath; providing a delivery catheter comprising a catheter shaft having a proximal portion slidably receiving a proximal narrow portion of the medical device and a distal portion slidably receiving a distal wide portion of the medical device; A push-in sheath is provided that includes a sheath shaft, at least a portion of the catheter shaft being preloaded within the sheath shaft, the sheath shaft comprising: a proximal portion slidably receiving the proximal portion of the catheter shaft; and an expandable distal portion slidably receiving the distal portion of the catheter shaft in an expanded state; advancing an expandable distal portion of the sheath shaft in the expanded state through the outer expandable sheath; advancing the delivery catheter relative to the in-line sheath to position the distal portion of the catheter shaft distal to the distal end of the expandable distal portion of the sheath shaft; and The medical device is advanced relative to the delivery catheter to position a distal wide portion of the medical device distal to the distal end of the catheter shaft.

18. The method of claim 17, and further comprising advancing the distal wide portion of the medical device into the heart chamber.

19. The method of claim 17 or 18, and further comprising activating a catheter engagement feature of a sheath hub of the in-line sheath to provide frictional contact between the in-line sheath and the delivery catheter to prevent proximal and distal translation of the delivery catheter relative to the in-line sheath.

20. The method of claim 17 or 18, and further comprising activating an outer sheath engagement feature of a sheath hub of the push-in sheath to engage with a hub of the outer expandable sheath to prevent distal and proximal translation of the push-in sheath relative to the outer expandable sheath.

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