Adjustable sheath device

Abstract

The present invention provides a dynamically expandable sheath that can expand within a blood vessel as a medical device passes through the sheath, and can contract to nearly its original size when the medical device is removed from the sheath. [Solution] The present invention relates to an adjustable sheath device for insertion into the body to provide intravascular access to various medical devices, and includes a dynamically expandable sheath 200 that is expandable in the blood vessel as the medical device passes through the sheath 200 and contractable to nearly its original size when the medical device is removed from the sheath 200. It generally comprises a rigid collar and an elongated sleeve having a continuous elastomer outer layer and an expandable inner layer.

Description

[Technical Field]

[0001] The technical field generally relates to adjustable sheath devices that are inserted into the body to provide intravascular access for various medical devices. This includes, but is not limited to, access to all arterial and vascular systems, abdominal and thoracic procedures, cerebrospinal procedures, genitourinary and gynecological procedures, and upper gastrointestinal and colorectal procedures. Embodiments of the present invention generally provide a dynamically expandable sheath that is expandable within a blood vessel when a medical device passes through the sheath, and is contractible to substantially return to its original size when the medical device is removed from the sheath. [Background Art]

[0002] Vascular introducer sheaths are common in endovascular procedures such as transcatheter aortic valve replacement (TAVR), angioplasty and stent placement, and are for introducing removable devices such as wires, balloons, and pressure transducers, as well as for introducing and deploying implantable devices such as mechanical aortic valves and stents, facilitating access to the vascular system.

[0003] Vascular introducer sheaths generally consist of a single hollow annular cuff, i.e., a sleeve. Once the introducer sheath is inserted, manipulated, and placed within the patient's vascular system, it allows devices to pass through the sleeve. The sleeve terminates at one end with an annular collar, which rests on the patient's skin and is positioned within the opening to the blood vessel. This collar generally forms a temporary seal around the opening to the blood vessel, and may include one or more inlets that allow devices and fluids to pass through the lumen of the sleeve into the patient's vascular system.

[0004] Furthermore, vascular introducer sheaths are designed to protect blood vessels from physical damage that can occur due to the insertion of medical devices into the vascular system, especially when the device is large relative to the lumen of the blood vessel. For example, TAVR procedures are commonly performed via the femoral artery, which in elderly patients is often smaller in diameter than the device itself. This often leads to arterial damage due to shear forces between the arterial wall and the device.

[0005] During endovascular procedures, it is common practice to insert and remove a series of introducer sheaths with increasing diameters to widen the vascular opening or vessel until it is large enough for the safe and unimpeded passage of an endovascular device. Depending on the size of the patient's vascular system, the procedure is started with the introduction of a small-diameter introducer sheath, and the diameter is gradually increased until the opening and the introducer sheath are large enough to allow for the delivery of a removable or implantable device.

[0006] For example, the introduction and advancement of a transcatheter aortic valve typically involves the insertion of a smaller diameter introducer to dilate the arterial entry site and vascular system before the insertion of a specific size sheath and introducer, which is often between 14 and 20 French diameters, depending on the size required to advance the transcatheter aortic valve replacement system. [Overview of the project] [Problems that the invention aims to solve]

[0007] The insertion and removal of each introducer sheath increases the overall procedure time and the risk of damage to the vascular wall. Although attempts are made to maintain instrument sterility and employ aseptic procedures in the operating room, the mere presence of intravascular openings and the introduction of foreign objects into the patient pose a risk of infection, and this risk increases with the number of objects being treated and the procedure time. Furthermore, blood loss and stress on the patient increase with procedure time and the introduction of objects into the patient. When introducer sheaths are inserted into the patient and into the patient's blood vessels, as the introducer sheaths progress through the patient's vascular system, vascular damage due to abrasion of the luminal surface of the vessel, and even rupture of the vessel itself, pose a significant risk at the vascular opening.

[0008] Past attempts to design and develop expandable introducer sheaths to minimize the need to introduce multiple sheaths during endovascular procedures have been largely unsuccessful. Expandable sheaths are designed to be inserted while constricted to a small diameter, expand once placed in a blood vessel, and then constrict again before removal to reduce their diameter. However, many are made from composite materials with an expandable portion extending along the longitudinal direction of the sheath. Because only a portion of the composite sheath material is expandable, these devices expand minimally and often do not expand sufficiently to reduce the need to introduce a larger second or third introducer sheath into the patient. Such composite constructions introduce structural fragility that leads to "ridgeding," or buckling, of the introducer sheath in the blood vessel, as the expandable portion collapses when forced through the vascular system, often resulting in device failure. Furthermore, expandable sheaths generally cannot constrict back to their original diameter, often causing damage to the blood vessel or its opening during their removal.

[0009] For example, when placed in a patient's body through an opening in the femoral artery, the introducer sheath plays a crucial role in protecting the patient's surrounding vascular system from damage or trauma that may occur as the introducer or device passes through curved or complex vascular pathways. However, many introducer sheaths are too rigid to navigate these curved and complex vascular pathways, potentially twisting, buckling, and failing during insertion and placement, which is why sheathless techniques are still frequently used in many surgeries. Physicians must weigh the trade-off between the safety of sheaths when passing through complex areas such as the iliofemoral system and sheathless devices, as the device itself tends to catch on or damage the luminal surface in curved sections of the vessel.

[0010] In procedures like TAVR, which offer a viable alternative to more invasive and risky open cardiac surgery, the safe passage of guidewires, introducers, and the mechanical valve itself through the surrounding vascular system is essential to extending the applicability of these critical corrective surgeries to patient groups that would otherwise be unsuitable.

[0011] For many patient groups, such as the elderly, traditional cardiac surgery to correct functional defects of the aortic valve carries far too high a risk. TAVR offers a safer alternative for these patients. However, even with the latest medical technology and generally best practices, TAVR procedures performed in Australia still resulted in 5.5% of patients experiencing major vascular complications, 8.5% with major bleeding, 1.6% with stroke, and 1.6% with myocardial infarction. Possible causes of these vascular injuries in TAVR include the patient's vessel diameter, the presence of atherosclerosis, the diameter of the introduced and retrieved sheaths, as well as sheath characteristics, including sheath stiffness and the degree of sheath's susceptibility to twisting or buckling.

[0012] Therefore, addressing any one of these areas of vascular damage during TAVR is expected to improve the safety of the procedure and enable it to be performed on a wider range of patients who are currently not suitable candidates for aortic replacement. [Means for solving the problem]

[0013] In various respects, aspects of the present invention relate to a retractable sheath for protecting the luminal surface of a blood vessel from the introduction of a medical device into the blood vessel, the retractable sheath comprising a rigid collar having an inner surface defining an internally extending passage, the rigid collar comprising an elongated sleeve attached to the rigid collar and expandable in the circumferential direction, the elongated sleeve comprising a proximal opening and a distal opening defining a luminal passage between the proximal opening and the distal opening, and the elongated sleeve comprising a continuous elastomer outer layer and at least a partially discontinuous expandable inner layer The expandable inner layer comprises two separate layers, the discontinuous portion of which comprises a rigid polymer sheet having properties such as generating an annular outward resistance when forcibly wound, the rigid polymer sheet being wound into a lumen formed by the continuous elastomer outer layer and extending longitudinally, and forming at least a portion of the expandable inner layer when positioned substantially in contact with the lumen surface of the continuous elastomer outer layer, the rigid collar being attached to the circumferentially expandable elongated sleeve at the proximal opening of the circumferentially expandable elongated sleeve.

[0014] This configuration provides a dynamically expandable sheath that can expand within a blood vessel as a medical device passes through the sheath, and can contract to nearly its original size when the medical device is removed from the sheath.

[0015] This functionality is achieved through a unique construction concept, where the elastomer outer layer applies counter-pressure to the expansion of the elongated sleeve, causing it to contract, while the expandable inner layer applies less counter-pressure to the contraction of the elongated sleeve, forming a passage within the expandable inner layer, although the counter-pressure of the elastomer outer layer is greater than that of the expandable inner layer. This configuration results in passive contraction of the elongated sleeve as the medical device passes through it. This configuration differs significantly from conventional introducer sheaths with a stretchable outer layer or a single stretchable layer, which generally cannot stretch uniformly in the radial direction, thus causing sheath buckling or failing to contract sufficiently close to its original size to allow for safe removal of the sheath.

[0016] It is well understood that the introducer sheath must provide a balance of properties including sufficient flexibility to advance through the vascular network, sufficient stiffness to prevent twisting and buckling, and sufficient elasticity to return to its original shape when expanded circumferentially or when involuntarily bent or twisted. The conceptual framework of the present invention makes it possible to provide complementarity of physical properties. Each layer of the elongated sleeve provides different physical properties, providing complementarity of physical properties that cannot be provided by either single material. That is, the expandable inner layer of an embodiment of the present invention provides stiffness, while the elastomer outer layer provides elasticity, and both provide a degree of flexibility sufficient to advance through the patient's vascular system.

[0017] Furthermore, the orientation of the seams along the longitudinal direction of the expandable inner layer, and / or the degree of overlap of the expandable inner layer, can be changed to adjust and optimize the elasticity and flexibility of the sheath.

[0018] Furthermore, the multilayer structure concept according to aspects of the present invention allows for a wider selection of materials for forming the elastomer outer layer and the expandable inner layer, thereby providing a better opportunity for those skilled in the art to optimize the physical properties of the expandable sheath or to find the desired physical properties of the expandable sheath.

[0019] The selection of appropriate materials must also conform to the desired shape of the expandable sheath or elongated sleeve. Individual shapes may provide functional characteristics as required in a particular embodiment.

[0020] For example, to facilitate insertion, embodiments of the present invention may include an elongated sleeve that is at least partially tapered along its longitudinal direction between the proximal and distal openings. The degree of tapering may be essential for certain applications, such as TAVR procedures where the valve may be considerably larger than the patient's femoral artery, and the degree of tapering is preferably such that it increases the ease with which the expandable sheath can be inserted into the vascular opening, in which case the insertion of the tapered sleeve may gently stretch and expand the vascular opening and the vessel itself, and the insertion of the device may be facilitated by insertion into the larger opening of the sleeve. Furthermore, the tapered shape may allow the sheath to be expanded with less introductory force than a non-tapered expandable sheath.

[0021] Therefore, it is preferable that the sleeve edge defining the distal opening has a circumference at least about 20% smaller than the sleeve edge defining the circumference of the proximal opening. Or, more specifically, it is preferable that the sleeve edge defining the distal opening has a circumference at least about 25% smaller than the sleeve edge defining the circumference of the proximal opening. In many applications such as TAVR, a distal opening having a circumference at least about 35% of the circumference of the proximal opening is preferred. In practice, the preferred circumference of the distal opening is in the range of about 35% to 40% of the circumference of the proximal opening.

[0022] A tapered shape may be achieved by molding only one of the elastomer outer layer or the expandable inner layer. For example, the expandable inner layer may be molded to be cylindrical and not tapered, and the tapered shape of the elongated sleeve is given by the tapered elastomer outer layer. Furthermore, the tapered shape of the expandable inner layer may be achieved by winding a rigid polymer sheath in a tapered shape.

[0023] A particular embodiment of the expandable sheath may comprise an elongated sleeve having a substantially cylindrical portion terminating at a proximal opening. Specifically, the expandable inner layer may comprise a substantially cylindrical continuous portion terminating at a proximal opening and a discontinuous rigid polymer sheet portion terminating at a distal opening, wherein the discontinuous rigid polymer sheet portion is wound within a lumen formed by a continuous elastomer outer layer and extends longitudinally, and is positioned substantially in contact with the lumen surface of the continuous elastomer outer layer.

[0024] In a preferred embodiment, the substantially cylindrical portion terminating at the proximal opening is sized to facilitate a strong seal to the vascular opening. Such non-tapered portions of the expandable inner layer may have axial seams, i.e., joints, or may be formed integrally with the discontinuous tapered portions. Preferably, the overlap of the discontinuous tapered portions of the rolled rigid polymer sheet increases from the proximal end to the distal end, forming a helical edge along the longitudinal direction of the elongated sleeve. The inclined edge may facilitate smooth expansion and contraction of the expandable inner layer.

[0025] Furthermore, the number of turns of the spirally wound rigid polymer sheet weakens, or reduces, the longitudinal rigidity of the rigid polymer sheet along the longitudinal direction of the sheath. This alters its properties not only in terms of resistance to radial expansion and contraction, but also through the flexibility of the sheath.

[0026] The expandable inner layer may have notches, slits, and other features to improve or modify the physical properties of the elongated sleeve, specifically its bendability, resistance to torsion, or elasticity.

[0027] The expandable inner layer may be integrally formed from a substantially uniform rigid polymer material provided with cuts or notches between the substantially cylindrical continuous portion and the discontinuous rigid polymer sheet portion. The discontinuous rigid polymer sheet portion may be wound in an overlapping state in a relaxed state, and configured to be helically wound around the longitudinal axis of the elongated sleeve.

[0028] Helical winding is generally preferred because it facilitates expansion and contraction of the discontinuous rigid polymer sheet portion. This also provides the best combination of properties including reduced susceptibility to kinking during delivery and the most typical flexibility.

[0029] Specifically, edges of the discontinuous rigid polymer sheet portion may be helically wound around the longitudinal axis of the elongated sleeve. The discontinuous rigid polymer sheet portion is preferably wound around the longitudinal axis of the sheath for a number of turns substantially equal to the number of turns that the distal portion is wound plus about 0.5 to about 1.5. More specifically, the number of turns is substantially equal to the number of turns that the distal portion is wound plus about 1.

[0030] When winding the discontinuous rigid polymer sheet portion around the longitudinal axis of the elongated sleeve, both the number of turns around the longitudinal axis of the elongated sleeve and the degree of overlap of the discontinuous rigid polymer sheet portion itself can individually or together change the performance characteristics of the sheath. The axial stiffness along the longitudinal direction of the sheath increases as the degree of overlap of the discontinuous rigid polymer sheet portion increases, whereas the stiffness can decrease as the number of turns of the discontinuous rigid polymer sheet portion itself around the longitudinal axis of the elongated sleeve increases.

[0031] The number of times the discontinuous rigid polymer sheet is wrapped around the longitudinal axis of the sheath may be increased to approximately equal to the number of times the distal portion is wrapped plus about 2. This can adjust the annular resistance of the sheet as the medical device passes through it, and as a result, can help protect the luminal walls of the patient's vascular system. Conversely, the flexibility of the sheath may be adjusted by reducing the number of wraps to approximately equal to the number of times the distal portion is wrapped plus about 0.5, thereby reducing the degree of overlap of the rigid polymer sheet and decreasing the degree of longitudinal rigidity of the rigid polymer sheet.

[0032] The shape of the cutout or notch may be selected from a variety of shapes, such as circular, triangular, oval, or T-shaped, or it may be selected based on the desired physical properties of the elongated sleeve.

[0033] The expandable inner layer may have a series of small notches along its longitudinal direction, which can improve the bendability of the elongated sleeve. For example, this may include a series of cuts or slits.

[0034] Alternatively, the expandable inner layer may be formed from a continuous thin strip. The strip may further comprise a series of coils projecting from its edges and aligned longitudinally, which are wound onto the continuous thin strip. The wound coils are typically between 1 mm and 10 mm in length, and the spacing between the coils is between 0.1 mm and 10 mm. In certain embodiments, the diameter of each coil may be constant along the longitudinal direction of the continuous strip, or it may vary along the longitudinal direction so that at least the coils at the distal end have a smaller diameter than the coils at the proximal end.

[0035] A rigid polymer sheet according to an embodiment of the present invention may be formed from a material comprising at least one selected from the group consisting of polyethylene, polypropylene, nylon, polyester, PTFE, copolymers thereof, or other biocompatible polymers. The rigid polymer sheet is preferably formed from polypropylene.

[0036] When certain materials are used, the edges of overlapping sections may come into contact with each other and become fixed in place, which can cause discontinuities in the expandable inner layer to become immobile when expanded. To avoid this problem, such edges may be rounded, blunted, or cut at a non-right angle.

[0037] The rigid polymer sheet may have at least three edges, in which case at least one edge terminates with an oblique cut. Furthermore, at least two substantially opposing edges may intersect at a terminal or edge defining a distal opening, and at least one of these two edges is formed by an oblique cut.

[0038] In another embodiment, the expandable inner layer may be formed from a continuous helically wound strip or wire. This expandable inner layer may be characterized by a strip or wire with a thickness of dimension "W", in which case it is wound with a helical pitch between "W" and "2W".

[0039] The pitch of the spiral strip is preferably between approximately 0.5 and 2 times the length of each strip, where the length of each strip is the axial length of the division. More specifically, a preferred spiral pitch is between 0.9 and 1.1 times the length.

[0040] The helical wire may be made of titanium, titanium alloy, or stainless steel, or a polymer material such as polyester, polyethylene, polypropylene, or other biocompatible material. The helical wire may be tapered along the longitudinal direction of the elongated sleeve.

[0041] The prior art discloses multilayer sheaths in which two or more layers are bonded together. A characteristic inherent to the configuration of such embodiments is that the combination of physical properties of each layer is lost when the layers are bonded together as a single unit.

[0042] Therefore, in a preferred embodiment of the present invention, the continuous elastomer outer layer and the expandable inner layer are movable relative to each other. Preferably, the tubular surface of the continuous elastomer outer layer and the outer surface of the expandable inner layer are movable relative to each other and preferably have a low coefficient of friction. Acceptable coefficients of friction are well known to those skilled in the art, and therefore, the selection of materials having a sufficiently low intrinsic coefficient of friction is well known to such those skilled in the art.

[0043] However, the inner and outer layers may be fixed to each other at their proximal ends, which may be achieved through welding, bonding, or direct relative attachment by clamping, or through attachment of both tubes to a hemostatic valve or similar device. This ensures that these layers are held in the desired position while remaining movable relative to each other.

[0044] Specifically, the proximal end of the inner layer may be attached to the hard collar by bonding the outer surface region of the expandable inner layer to the inner surface of the hard collar. The elastomer outer layer may be held in place once positioned on the outer surface of the hard collar by making the circumference of the proximal side in a relaxed state less than or equal to the outer circumference of the hard collar.

[0045] In certain embodiments, the elongated sleeve may have a lubricating layer or surface treatment between the luminal surface of the continuous elastomer outer layer and the outer surface of the expandable inner layer. Such a configuration preferably includes at least one selected from the group consisting of silicone, glycerin oil, PTFE, or hydrophilic polymers to reduce the coefficient of friction. The lubricating layer may further include a hydrogel-based coating that can contain a pharmaceutical agent for treating or preventing infection or allergies. These substances or other hydrophilic coating materials may be applied to the inner surface of the expandable inner layer to reduce the coefficient of friction between the medical device and the expandable sheath.

[0046] Now, looking at the configuration of several embodiments of the elongated sleeve, the continuous elastomer outer layer may be formed from an elastomer material, and as a result, the continuous elastomer outer layer can expand when the elastomer material is stretched and contract when the elastomer material is relaxed. Preferably, with the appropriate selection of material, the elastomer material can be made to return to a circumference of no more than approximately 135% of its initial circumference when it contracts. Generally, the resting circumference of the proximal edge is about 135% larger than the resting circumference of the distal edge, and therefore the elastomer material must be able to return to a circumference of at least the size of the proximal opening. It is even more preferable that the elastomer material can return to a circumference in the range of about 115% to about 120% of its initial circumference when it contracts, although this may be about 117%.

[0047] Furthermore, by selecting appropriate materials, it is possible to ensure that, when the elastomer material is stretched, the continuous elastomer outer layer expands to at least 1.35 times its unstretched circumference. Ideally, the desired stretchability of the elastomer material should not limit the type of medical device that can pass through it; therefore, it is preferable that the continuous elastomer outer layer expands to approximately 300% to 400% of its unstretched circumference when the elastomer material is stretched.

[0048] The continuous elastomer outer layer is preferably formed from one of the group consisting of latex rubber or non-latex substitutes, including nitrile rubber, polyvinyl chloride, neoprene, polypropylene, and polyisoprene. The continuous elastomer outer layer is preferably formed from a silicone material or a silicone composite material.

[0049] The preferred material for forming the elastomer outer layer is selected from materials that can be formed to a thinness that provides sufficient counterpressure to contract the expandable inner layer without rupturing. In this way, the user does not need to apply significant force to the medical device to forcibly expand the elastomer outer layer during insertion, which would otherwise risk damaging blood vessels. For this reason, the continuous elastomer outer layer is preferably about 0.2 mm thick or less. More specifically, the continuous elastomer outer layer is preferably about 0.1 mm thick.

[0050] In a preferred embodiment, the rigid collar is provided by a hemostatic valve connector. The hemostatic valve connector may include a hemostatic valve to prevent the patient from losing blood from the opening of the blood vessel. The hemostatic valve connector may further include an opening for introducing the medical device into the lumen of an elongated sheath. The hemostatic valve connector may also include one or more inlets for introducing fluid into the patient's vascular system.

[0051] To improve the visibility of medical devices or retractable sheaths in X-ray imaging equipment during medical procedures, elongated sleeves may be equipped with radiopaque markers. The radiopaque markers are preferably located at the distal end of the elongated sleeve and may be evenly bonded to the elastomer outer layer or the expandable inner layer. The radiopaque markers may be metal wires such as nitinol, which may be bonded to or sewn onto the elongated sleeve, or they may be polymer-based, such as tungsten-filled nylon, polyethylene, or polyurethane, and bonded to the elongated sleeve. Alternatively, the radiopaque markers may be bonded to the elastomer outer layer and the expandable inner layer, joining these layers together at the distal end of the elongated sleeve.

[0052] During insertion of the retractable sheath into the patient, a rigid introducer may be inserted into the expandable inner layer. In certain embodiments, the retractable sheath may have a rigid introducer protruding from the distal end of an elongated sleeve within the lumen of the elongated sleeve.

[0053] During insertion, the rigid introducer may be positioned to protrude from the distal end of the expandable medial layer. The rigid introducer typically has a tapered tip. The rigid introducer may also have a small opening for passing a wire previously inserted into the blood vessel.

[0054] The rigid introducer may be tapered to match the diameter of the distal opening of the elongated sleeve, or to match the outer contour of the elongated sleeve. Alternatively, the outer surface of the rigid introducer may be stepped to match both the distal inner diameter and the proximal inner diameter of the expandable inner layer.

[0055] Following the insertion of the retractable sheath, the rigid introducer may be removed to allow another device to move through the lumen of the elongated sleeve.

[0056] The use of the expandable sheath according to an aspect of the present invention may include the steps of obtaining the expandable sheath according to that aspect, passing a rigid introducer through the lumen of the expandable sheath, and introducing the expandable sheath into a blood vessel.

[0057] A method according to an aspect of the present invention may further comprise the steps of removing a rigid introducer and passing a medical device through the lumen of a retractable sheath.

[0058] The expandable sheath according to an aspect of the present invention is preferably manufactured by the steps of obtaining a rigid collar, an elastomer outer layer, and an expandable inner layer, as described in accordance with the aspect; attaching the expandable inner layer to the rigid collar at the proximal opening; and positioning the expandable inner layer inside the elastomer outer layer.

[0059] Alternatively, the elastomer outer layer may be molded simultaneously within the hard collar.

[0060] Herein, a broad range of embodiments of the present invention will be described with reference to the accompanying drawings, in addition to the examples and preferred embodiments disclosed in the detailed description. The present invention may be embodied in many different forms and should not be construed as being limited to the embodiments described herein. These embodiments are presented for illustrative purposes only, in order to convey the full scope and breadth of the present invention, which is sufficient and adequate for this disclosure. [Brief explanation of the drawing]

[0061] [Figure 1] This image shows a computed tomography scan illustrating the pathway from the femoral artery through the left and right iliac arteries to the abdominal arteries. [Figure 2] This is a front perspective view of an adjustable sheath according to an embodiment of the present invention. [Figure 3(a)] This is a side view showing a sheath collar according to an embodiment of the present invention. [Figure 3(b)]This is a rear perspective view showing a sheath collar according to an embodiment of the present invention. [Figure 3(c)] This is a front perspective view showing a sheath collar according to an embodiment of the present invention. [Figure 4(a)] This is a side view of an adjustable sheath according to an embodiment of the present invention. [Figure 4(b)] This is a cross-sectional view of an adjustable sheath according to an embodiment of the present invention, in section AA. [Figure 4(c)] This is a cross-sectional view of the adjustable sheath according to an embodiment of the present invention, in cross-section BB. [Figure 4(d)] This is a cross-sectional view of the adjustable sheath in cross-section CC according to an embodiment of the present invention. [Figure 5(a)] This is a rear perspective view showing an adjustable sheath according to an embodiment of the present invention, together with an introducer. [Figure 5(b)] This is a side view of the introducer passing through the lumen of an adjustable sheath. [Figure 5(c)] This is a cross-sectional view of the adjustable sheath and introducer in DD section. [Figure 6(a)] This is a front perspective view showing an adjustable sheath according to an embodiment of the present invention, with the outer elastomer tube removed, and showing a linearly cut inner layer. [Figure 6(b)] This is a front perspective view showing an adjustable sheath according to an embodiment of the present invention with the outer elastomer tube removed, and showing an inner layer that is cut in a straight line and has further notches. [Figure 6(c)] This is a front perspective view showing an adjustable sheath according to an embodiment of the present invention, with the outer elastomer tube removed, and showing the spirally cut inner layer. [Figure 7(a)] This is a front perspective view of an adjustable sheath according to an embodiment of the present invention, showing the V-shaped inner layer with the outer elastomer tube removed and in an expanded state. [Figure 7(b)]These are lateral cross-sectional views relating to embodiments of the present invention, showing the inner layer in an expanded state, a partially expanded state, and a contracted state, respectively. [Figure 8] This graph shows the bendability of an adjustable sheath according to an embodiment of the present invention, each having an inner layer that is cut in a straight line, a spiral, and a V-shape. [Modes for carrying out the invention]

[0062] Some aspects of the present invention will be described in the following embodiments.

[0063] The computed tomography scan images shown in Figure 1 illustrate the pathways that removable or implantable medical devices, such as mechanical aortic valves, should take when being delivered through the arterial pathway from the femoral artery through the left and right iliac arteries to the abdominal artery. The terminal portions of the right and left femoral arteries are indicated by 110(a) and 110(b), respectively. The right and left iliac arteries are indicated by 120(a) and 120(b), respectively, and the abdominal artery is indicated by 130. The pathways of a medical device inserted into the femoral artery to the abdominal artery are shown along the dotted lines in the left image for entry via the right femoral artery 120(a) and in the right image for entry via the left femoral artery 120(b).

[0064] The shape of the pathway shown in Figure 1 illustrates several vascular curves that the medical device must overcome during insertion to reach the required position for placement. Since the image is only two-dimensional, it does not show the pathway that must pass through complex skeletal structures, including the pelvis, in three dimensions. During use, the device is typically attached to an elongated introducer for manipulation through the vascular system, and often considerable force is applied to the introducer to guide the device through the lumen of the vessel. During this process, the greatest risk of vascular damage occurs where the vessel is narrowest. The introducer sheaths of the form described herein protect the luminal surface from damage caused by the insertion of the medical device and / or introducer. Depending on the characteristics of the device, or the location of insertion or delivery, the introducer sheath may be a short structure for placement and protection around the opening of the vessel and a short pathway into the vessel, or it may be longer so that a longer pathway extends from the opening of the vessel to protect longer portions of the lumen wall.

[0065] Figure 2 shows an adjustable sheath 200 suitable for use as an introducer sheath as described above. The adjustable sheath 200 broadly consists of two main components: a rigid, cylindrical collar 210 and an elongated, tapered sleeve 220. The collar 210 is a hollow structure configured to allow material to be supplied into the inner lumen of the sleeve 220 through the larger opening of the sleeve 220. The cylindrical collar 210 is made of a rigid material so that the user can handle the collar and pass an object or material through it. The collar 210 terminates with a narrowed opening of a similar diameter to the larger opening of the sleeve 220, connecting these two components by allowing the sleeve 220 to be placed and secured within it.

[0066] The sleeve 220 tapers away from the collar 210 to facilitate insertion into the incision formed to enter the patient's vascular system. The sleeve 220 has a smooth, flexible structure that tapers from the proximal end 230 and narrows towards the distal end 240 to facilitate insertion and advancement of the sheath into the blood vessel. The sleeve 220 is expandable and expandable to allow larger introducers, valves, or other medical devices to be introduced into the patient through the lumen of the sleeve, and can expand around the device, gently pressing against the lumen wall of the vessel as it moves through the vessel, and can also contract to its original size so that the device can be gently removed from the patient when the device is removed.

[0067] Figure 3 shows the structure of the collar 210. Figure 3a shows three main parts formed within the collar 210, including a valve section 310 having a hemostatic valve (not shown) inside, a connector section 320 providing an inlet or other connector for entering a blood vessel, and a fixing section 330 for securing a sleeve 220 (not shown) inside. Figure 3b shows the arrangement of the hemostatic valve 340 located within the valve section 310. The hemostatic valve 340 may be pierced or punctured to allow the device to enter the lumen of the sleeve through the sheath collar and return to a closed state to prevent backflow of fluid from the blood vessel. Figure 3c shows the arrangement of an inlet 350 for connecting a medical fluid conduit to the sheath collar to introduce fluid to the patient.

[0068] Color 210 is formed from a rigid polymer such as polyethylene, polyester, or polypropylene, but may also be formed from any rigid biocompatible material that is deemed suitable for the intended purpose by those skilled in the art.

[0069] Figure 4a is a side view of the expandable sheath 200, showing the appearance of the collar 210 and the outer surface of the sleeve 220. The sleeve 220 is formed from two thin, flexible layers: an outer elastomer tube 410 and an expandable inner layer 420. The outer elastomer tube 410 is formed as a tapered, elongated tube that holds a sheet inside, which is rolled to form the expandable inner layer 420.

[0070] The outer elastomer tube 410 is formed from an elastomer material that can stretch when pressure is applied from within the lumen of the sleeve, but returns the sleeve to substantially its original diameter when the internal pressure is reduced. The outer elastomer tube has a wall thickness of less than 0.2 mm, preferably less than 0.1 mm, in the relaxed state. The outer elastomer tube 410 is formed from silicone to maximize elasticity and minimize wall thickness, thereby minimizing the risk of damage to the vascular system. However, those skilled in the art may select other materials for use if they are deemed to have suitable properties. These materials may include latex rubber, or non-latex substitutes such as nitrile rubber, polyvinyl chloride, neoprene, polypropylene, and polyisoprene.

[0071] Figure 4a shows cross-sectional points at points AA, BB, and CC. Figure 4b shows a cross-section at point AA, indicating that the sleeve is in a relaxed state at its largest diameter at the proximal end 230, and consequently, the outer elastomer tube 410 is also at its largest diameter. In the AA section, the expandable inner layer 420 is a single layer of uniform thickness around the entire inner circumference of the sleeve 220.

[0072] Figure 4c shows a cross-section at point BB, illustrating the internal structure of the sleeve 220, where the outer elastomer tube 410 is tapered and has a smaller diameter than the diameter in cross-section AA. The expandable inner layer 420 is shown overlapping to the extent that it is folded twice. On the other hand, Figure 4d shows a cross-section at point CC, illustrating the internal structure of the sleeve 220, where the outer elastomer tube 410 is smallest at the distal end 240 of the sleeve 220. At this point, the expandable inner layer 420 is shown overlapping to the extent that it is folded three times.

[0073] The inner tube may be formed from a polymer material such as polyethylene, polypropylene, nylon, polyester, PTFE, or other film-like material.

[0074] The expandable inner layer 420 is formed as a sheet of polymer material such as polyethylene, polypropylene, nylon, polyester, PTFE, or other film-like material, and is cut to approximately the same length as the outer elastomer tube 410 and to the width required to wind it three times within the distal end 240 of the sleeve 220. The appropriate material is selected according to its stiffness when wound helically at a pitch equal to approximately 1 plus the helical pitch at the distal end. However, as is well known to those skilled in the art, several materials may be suitable for forming the expandable inner layer 420.

[0075] The expandable inner layer may consist of rolled or wound sheets, but a better configuration is to start with an extruded tube, then cut along its longitudinal axis, and then roll or wound the sheet portion. A suitable material has a balance of elasticity and flexibility that allows for expansion and contraction without permanent deformation, and resists buckling and crushing. Preferred material choices are polypropylene or polyethylene.

[0076] The expandable inner layer 420 and the outer elastomer tube 410 are fixed to each other at the proximal end 230. They may be joined by welding, bonding, clamping, or by attaching each to the collar 210. The expandable inner layer 420 and the outer elastomer tube 420 can move freely relative to each other along the longitudinal direction of the sleeve 220. A lubricant such as oil, grease, hydrogel, or other low-friction surface treatment agent may be applied between the expandable inner layer 420 and the outer elastomer tube 420 to facilitate movement between them. At the distal end 240 of the sleeve 220, the expandable inner layer 420 and the outer elastomer tube 410 may be joined to each other at a portion of the circumference of the outer elastomer tube 410. They may be joined by welding, bonding, or suturing.

[0077] Furthermore, the expandable inner layer 420 and the outer elastomer tube 410 may be sutured or stapled with radiopaque materials such as stainless steel, titanium, nickel-titanium alloy, or other metals or metal alloys for sensing purposes.

[0078] Figures 5a–5c illustrate the exemplary use of the adjustable sheath 200 when passing the introducer device 510 through the internal lumen of the adjustable sheath 200. During insertion into the vascular system, the introducer device 510 can pass through the hemostatic valve 340, be pushed through the internal lumen of the sheath collar 210, and be inserted through the expandable inner layer 420 (not shown) of the sleeve 220. As shown in Figure 5b, the introducer device 510 passes through the expandable inner layer 420 and protrudes from the distal end 240 of the sleeve 220. The tapered end 520 of the introducer device 510 can be temporarily held within the distal end 240 of the outer elastomer tube 410. Figure 5c shows that the expandable inner layer 420 gradually expands, reducing the degree to which it overlaps itself.

[0079] Furthermore, to facilitate the feeding of the device through the expandable inner layer 420, the inner surface of the lumen wall may be coated with a lubricating coating such as silicone, glycerin oil, PTFE, hydrophilic polymer, or other low-friction surface.

[0080] Similarly, the outer elastomer tube 410 can be coated with a low-friction layer on its outer surface to increase ease of insertion into the vascular system. Surface treatments may include hydrogel-based coatings that can contain pharmaceutical agents for treating or preventing infection or allergies, as well as those that may be applied to the expandable inner layer.

[0081] The introducer device 510 is formed to have a tapered shape at its tip that conforms to the internal shape of the expandable inner layer 420. However, the introducer device 510 may be formed with a uniform diameter to match the inner diameter of the expandable inner layer 420, or it may be formed with stepped diameters at its proximal and distal ends to match the respective inner diameters of the expandable inner layer 420. After the adjustable sheath is inserted into the blood vessel, the introducer device 510 can be removed and another device can be passed through the internal lumen of the adjustable sheath 200.

[0082] The introducer device 510 may have a small hole at its tip that allows a wire previously inserted into the blood vessel to pass through.

[0083] The introducer device 510 may consist of multiple components, with the outer side temporarily clamped between two or more components, allowing the user to adjust the position of the components of the introducer device 510 and release the outer elastomer tube 410. In an alternative embodiment, the outer elastomer tube 410 may be folded within an expandable inner layer 420 at the distal end 240, so as described above, it may be held by the introducer device 510 during vascular insertion and released when the introducer device 510 is removed.

[0084] Figures 6a and 6c show the adjustable sheath 200 with the outer elastomer tube 410 removed. As shown in Figure 6a, the expandable inner layer 420 is formed as a sheet cut to have a single longitudinal seam line 610 when rolled in a tapered shape with overlapping sections. At the proximal end 230, the outer elastomer tube 410 has a non-tapered portion to facilitate a strong seal to the vascular opening. The non-tapered proximal end 230 is circumferentially connected to the rest of the expandable inner layer 420 but shares a seam or seam line around a continuous axis.

[0085] The expandable inner layer 420 may be cut and molded into many different shapes. Alternatively, the expandable inner layer 420 may be rolled to form a non-tapered cylinder in its relaxed state, in which case the tapered shape is provided by the tapered outer tube.

[0086] Figures 6b and 6c show optional features such that the expandable inner layer 420 is further characterized by a notch 620 at the distal end 240 of the tapered section 630, separating the tapered section 630 from the non-taped section 640. The notch 620 forms an opening 650 in the expandable inner layer 420, thereby allowing the tapered section 630 to continue to the non-taped section 640 without causing twisting and localized crushing of the sleeve 220, as the opening 650 partially extends circumferentially around the sleeve 220. The notch 620 can also increase ease of manufacturing by reducing the risk of the device being inserted being accidentally fed between the expandable inner layer and the outer elastomer tube. It can also improve the buckling and torsional strength of the adjustable sheath. The shape of the opening can be selected to be a variety of shapes, such as circular, triangular, oval, or T-shaped. The selected shape may be optimized through trial and error and testing of the desired physical properties of the adjustable sheath.

[0087] Figure 6c shows another embodiment in which the tip section 630 is discontinuous. This discontinuous portion is rectangular along the entire length of the tip section 630, but the degree of overlap along the longitudinal direction of the tip section increases from the proximal end to the distal end, generating a helical edge 650 along the longitudinal direction of the tube.

[0088] Figure 7a shows another embodiment in which, in the expanded state, the edges are not parallel, i.e., form a V-shaped cut, and the circumference of the inner layer at the distal end is smaller than the circumference of the inner layer at the proximal end. With this configuration, as shown in Figure 7a, a smaller overall distal diameter can be easily obtained by reducing the thickness of the material due to the overlapping layers. In the event of excessive expansion, the tip section 630 separates at the junction line 610. To prevent the expandable inner layer 420 from becoming fixed in the expanded state within the blood vessel as one blunt edge of the expandable inner layer 420 wedge against the other blunt edge of the expandable inner layer 420, the edges of the overlapping portion may be rounded or cut at a non-right angle. Figure 7b shows the movement of one edge of the expandable inner layer 420 relative to the other edge when it deflates after excessive expansion, when cut at a non-right angle. When one edge contacts the other, the outer edge 710 slides over the inner edge 710 until the expandable inner layer 420 retracts to approximately its original position.

[0089] In another embodiment, the expandable inner layer 420 is formed by a continuous strip or wire, characterized by a thickness of dimension "W" and wound helically with a helical pitch between "W" and "2W". The helical winding can be formed from wire such as titanium, titanium alloy, or stainless steel, or from polymer material such as polyester, polyethylene, polypropylene, or other biocompatible material. The helical winding tapers from the distal end to the proximal end.

[0090] In yet another embodiment, the expandable inner layer 420 is formed of a continuous thin strip, the strip having a series of coils wound in orthogonal directions extending from one end of the continuous strip back onto it. The wound coils are typically between 1 mm and 10 mm in length and are spaced between 0.1 mm and 10 mm apart. In a particular embodiment, the diameter of each coil may be constant along the longitudinal direction of the continuous strip, or the diameter may be varied along the longitudinal direction so that the coils at least at the distal end have a smaller diameter than the coils at the proximal end.

[0091] In certain embodiments, an opening may be provided at the proximal end 230 of the outer elastomer tube 410 to allow for the removal of air trapped between the outer elastomer tube 410 and the expandable inner layer 420 before inserting the adjustable sheath into the vascular system, and this opening may be closed by a valve (not shown). Before use, a liquid such as saline or a sterile agent may be introduced through this valve into the space between the inner and outer tubes prior to the medical procedure.

[0092] To improve the visibility of the adjustable sheath by an X-ray imaging device during medical procedures, radiopaque markers may be incorporated into the sleeve, specifically the distal end 240. These markers may be metal wires such as nitinol bonded or sutured to the tube, or polymer materials such as tungsten-filled nylon, polyethylene, or polyurethane bonded to the tube, or similar configurations known to those skilled in the art. The radiopaque markers can be incorporated at any number of locations in the expandable inner layer 420 or the outer elastomer tube 410.

[0093] <Preliminary Test of Embodiment> [Stretchable] Test details: Measure the diameter of the sheath before inserting the introducer and after withdrawing the introducer. Report the shrinkage rate of the sheath relative to its original diameter. Report the force required to withdraw the introducer.

[0094] Criteria for evaluation: Target maximum contraction rate.

[0095] Number of test samples: One sample each of the following: standard sheath, linearly cut tapered prototype sheath, spirally cut tapered prototype sheath, and V-shaped cut tapered prototype sheath.

[0096] Methods: The proximal and distal outer diameters of the sheath under test were measured before inserting the introducer. The introducer was then inserted into the sheath until it protruded from the distal end. The introducer was then withdrawn from the sheath and completely removed. The force required to withdraw the introducer was recorded to assess any difficulty in doing so. The distal outer diameter of the sheath was then measured again to assess the amount of shrinkage or springback. The shrinkage ratio was then calculated as a ratio to the initial distal shrinkage.

[0097] result [Table 1]

[0098] All samples underwent smooth insertion of the introducer, requiring no excessive force to insert it. All adjustable sheaths clearly exhibited the characteristic of retracting to the limit of the sheath's capacity after the introducer had protruded from the end of the sheath.

[0099] After the introducer was withdrawn, the V-shaped cut sample did not shrink completely because the cut ends collided and did not overlap properly. The outer layer of the V-shaped cut sample was pulled back approximately 4 mm from the edge of the inner layer, which is likely due to increased friction against the introducer.

[0100] Conclusion: All prototype sheaths clearly demonstrated the ability to contract after inserting and withdrawing the introducer. The V-shaped cut specimen showed the smallest distal end measurement but did not contract as intended. The straight-cut and spiral-cut specimens showed nearly equivalent performance, but other performance characteristics should be considered when selecting a preferred configuration. The force required to withdraw the valve feeding mechanism was not excessive for any of the configurations and did not pose a risk of problem or injury to the user.

[0101] [Bendability] Test details: Measure the force required to bend the sheath at an angle of up to 30° without an introducer.

[0102] Judgment criteria: The force required to bend the sheath to an angle of up to 30°. This force must not exceed the standard force.

[0103] Number of test samples: One sample each of the following: standard sheath, linearly cut tapered prototype sheath, spirally cut tapered prototype sheath, and V-shaped cut tapered prototype sheath.

[0104] Method: A jig for holding the sheath was constructed with a cantilever length of 200 mm. The sheath was bent using a handheld force gauge, and the applied force was recorded in grams. The applied force was converted to Newtons for matching purposes.

[0105] Results: The table below shows the bending force in N for each sample. [Table 2]

[0106] Conclusion: All prototype sheaths clearly demonstrated improved bendability compared to the reference sample. The three different prototype sheaths exhibited different bendability and stiffness, as shown in Figure 8.

[0107] [Sheath twisting characteristics] Test details: Measure the force required to twist the sheath and the angle at which the twist occurs.

[0108] Criteria: The angle required to twist the sheath must exceed the standard.

[0109] Number of test samples: One sample each of the following: standard sheath, linearly cut tapered prototype sheath, spirally cut tapered prototype sheath, and V-shaped cut tapered prototype sheath.

[0110] Method: A jig for holding the sheath was constructed with a cantilever length of 200 mm. The sheath was bent using a handheld force gauge, and the applied force was recorded in grams. The applied force was converted to Newtons for consistency. The angle relative to the torsion was read by referring to a template and represents the angle between the axis of the sheath and the line connecting the bending point to the distal end of the sheath.

[0111] result: [Table 3]

[0112] The spirally cut and V-shaped cut samples were able to bend beyond a 90-degree angle without twisting. Since these samples exceeded the test capacity, testing was stopped at this point.

[0113] Conclusion: All prototype devices clearly demonstrated improved resistance to twisting compared to the baseline. Both the V-shaped and spiral-cut samples bent more than the straight-cut samples without twisting.

[0114] <Manufacturing of the Embodiment> The adjustable sheath is constructed by manufacturing an expandable inner layer and an outer elastomer tube, and then assembling and bonding both of these components to a commercially available collar with a hemostatic valve.

[0115] The expandable inner layer is manufactured from medical-grade polyamide according to standard extrusion or injection molding techniques. For linearly cut inner layers, the raw material is extruded into a tapered, elongated cylindrical shape and cut along the length of the molded body.

[0116] In the case of a spiral inner layer, once the inner layer is molded to the desired size and shape, it is heat-shrunk around a mold of the desired diameter to form a cylindrical portion for bonding to the collar. The remaining sheet portion of the inner layer is cut at an oblique angle to create the shape necessary for spiraling within the outer elastomer tube.

[0117] The outer elastomer tube is formed from silicone into a desired tapered shape using resin molding techniques known to those skilled in the art, which are suitable for molding and curing thin silicone sheets and tubular structures. The proximal portion of the outer elastomer tube is formed to have the same or slightly larger diameter than the cylindrical portion of the expandable inner layer.

[0118] The sheet portion of the expandable inner layer is manually wound into a spiral with a diameter smaller than that of the outer elastomer tube, aligned with the tube at its proximal end, and then placed inside the tube. A small amount of adhesive is applied to the proximal end (i.e., the larger end) of the tapered sleeve, so that the adhesive contacts the outer elastomer tube and the expandable inner layer. Next, the proximal end is positioned around the opening of a commercially available hemostatic valve, and both the expandable inner layer and the outer elastomer tube are bonded to the collar of the hemostatic valve. Once the adhesive has cured, the sheath is ready for use.

[0119] Throughout this specification, the term “comprise,” or variations such as “comprises,” or “comprising,” means to include the element, integer, or step, or group of elements, integers, or steps described, but not to exclude other elements, integers, or steps, or groups of elements, integers, or steps.

[0120] It will be understood that the terms “fastener,” or “fastening,” “connection,” or “sealing,” when used alone or in conjunction with another term such as “means,” may be used interchangeably if the interpretation of the terms can be considered functionally interchangeable with that of another by a person skilled in the art. Furthermore, the use of one of the aforementioned terms does not preclude interpretations that include another term.

[0121] Various devices and components of devices described herein may be provided in various sizes and / or dimensions as needed. Appropriate sizes and / or dimensions will vary depending on the specifications of the components to be connected or the field of use, and can be selected by those skilled in the art.

[0122] It will be understood that features, elements, and / or characteristics described in relation to one embodiment of this specification may be used in conjunction with other embodiments of the invention as needed.

[0123] Preferred embodiments of this specification are disclosed for illustrative purposes only, but those skilled in the art will understand that various modifications, additions, and substitutions are possible without departing from the scope and spirit of this specification and the appended claims.

[0124] When an element or layer is described as being "on top of" or "inside" another element or layer, it will be understood that the element or layer can exist directly on top of or inside the other element or layer. Conversely, when an element is described as being "directly on top of" or "directly inside" another element or layer, it will be understood that there is no intervening element or layer.

[0125] As used herein, the term "and / or" includes any combination of one or more of the items listed together, and all combinations thereof.

[0126] The terms First, Second, Third, etc., may be used herein to describe various elements, components, regions, layers, and / or parts, but it will be understood that these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are used solely to distinguish one element, component, region, layer, or part from another region, layer, or part. Accordingly, without departing from the teachings herein, the First element, component, region, layer, or part may be referred to as the Second element, component, region, layer, or part.

[0127] Spatially relative terms such as “downward,” “upward,” “top,” “bottom,” “left,” and “right” may be used herein to describe the relationship between one element or feature and another, as shown in the diagrams, for the sake of clarity. It should be understood that spatially relative terms are intended to encompass different orientations of the components in use or operation, in addition to the orientations shown in the diagrams. For example, if the device in the diagram is turned over, an element described as “downward” relative to another element or feature would be located “upward” relative to that other element or feature. Thus, the exemplary term “downward” may encompass both upward and downward orientations. Devices may also be oriented in other ways (e.g., a 90-degree rotation, or other orientations), and the spatially relative descriptive terms used herein should be interpreted accordingly.

[0128] The terms used herein are for the sole purpose of describing specific embodiments and are not intended to limit the invention. Where used herein, the singular forms “a,” “an,” and “the” are intended to include the plural form unless the context otherwise explicitly indicates. It will be further understood that the terms “include,” “equip,” and / or “equip,” where used herein, identify the presence of the described features, integers, steps, actions, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, actions, elements, components, and / or groups thereof.

[0129] This specification describes embodiments based, for example, on illustrations and / or cross-sectional views illustrating the outline of preferred embodiments (and intermediate structures) disclosed. In this specification, deformation from the illustrated shape is expected, for example, due to manufacturing techniques and / or tolerances. Therefore, the embodiments disclosed should not be construed as being limited to the specific shapes of the components shown herein, and include, for example, errors in shape due to manufacturing.

[0130] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as those generally understood by those skilled in the art to which this specification belongs. Furthermore, terms as defined in commonly used dictionaries should be interpreted to have a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0131] Any reference in this specification to “one embodiment,” “one example,” or “exemplary embodiment” means that any particular feature, configuration, or characteristic described in relation to that embodiment is included in at least one of the disclosed embodiments. The appearance of such phrases in various parts of this specification does not necessarily refer to the same embodiment. Furthermore, if a particular feature, structure, or characteristic is described in relation to one embodiment, it is within the comprehension of those skilled in the art to practice and / or use such feature, structure, or characteristic in relation to another embodiment.

[0132] Furthermore, the embodiments are intended to include, or extend to, methods of use and methods of manufacture for any or all of the elements disclosed in the above description.

[0133] As described above, the present invention has been explained based on specific embodiments, but it should be understood that the present invention is not limited to these disclosed embodiments. By reading the teachings herein, many modifications and alternative embodiments of the present invention will be conceived by those skilled in the art to which the present invention relates, but these are intended and encompassed by both this specification and the appended claims.

[0134] All publications referenced herein are incorporated herein by reference. Any descriptions of documents, acts, substances, devices, articles, etc. contained herein are intended solely to illustrate the context relating to the present invention. It should not be construed as accepting that any or all of these matters constitute part of the prior art or were well known in the relevant art of the present invention, even if they existed in Australia or elsewhere prior to the date of the priority claim of this application.

[0135] In fact, the scope of the present invention should be determined by the proper interpretation and construction of the appended claims and their legal equivalents, as understood by those skilled in the art based on the disclosure herein and the appended drawings.

Claims

1. A retractable sheath for protecting the luminal surface of a blood vessel from the introduction of a medical device into the blood vessel, It has a hard collar with an inner surface that defines the passage extending inside, The rigid collar has an elongated sleeve attached to the rigid collar that is expandable and contractible in the circumferential direction, and the elongated sleeve has a proximal opening and a distal opening, defining a lumen between the proximal opening and the distal opening. The elongated sleeve comprises two separate layers, including a continuous elastomer outer layer and an expandable inner layer that is at least partially discontinuous, wherein the discontinuous portion of the expandable inner layer comprises a rigid polymer sheet that, when forcibly wound, generates an annular outward resistance, the rigid polymer sheet is wound within the lumen formed by the continuous elastomer outer layer and extends longitudinally, and when positioned substantially in contact with the lumen surface of the continuous elastomer outer layer, forms at least a portion of the expandable inner layer. The rigid collar is attached to the elongated sleeve at the proximal opening of the elongated sleeve, which is expandable in the circumferential direction. Extendable sheath.

2. The expandable inner layer comprises a substantially cylindrical continuous portion terminating at the proximal opening and a discontinuous rigid polymer sheet portion terminating at the distal opening, wherein the discontinuous rigid polymer sheet portion is wound within a lumen formed by the continuous elastomer outer layer and extends longitudinally, and is positioned substantially in contact with the lumen surface of the continuous elastomer outer layer, according to claim 1.

3. The retractable sheath according to claim 2, wherein the discontinuous rigid polymer sheet portion is wound in a relaxed state with overlaps and is configured to be wound spirally around the longitudinal axis of the elongated sleeve.

4. The edge of the discontinuous rigid polymer sheet portion is spirally wound around the longitudinal axis of the elongated sleeve, as described in claim 3.

5. The retractable sheath according to claim 4, wherein the discontinuous rigid polymer sheet portion is wound around the longitudinal axis of the retractable sheath for approximately 0.5 to 1.5 times the number of times the distal portion is wound.

6. The retractable sheath according to claim 1, wherein the rigid polymer sheet has at least three edges, and at least one edge terminates with an oblique cut.

7. The retractable sheath according to claim 6, wherein the rigid polymer sheet comprises at least three edges, at least two substantially opposing edges intersecting at a point or edge defining the distal opening, and at least one of the two edges is formed by an oblique cut.

8. The expandable sheath according to claim 1, wherein the continuous elastomer outer layer and the expandable inner layer are movable relative to each other, and the tubular surface of the continuous elastomer outer layer and the outer surface of the expandable inner layer are movable relative to each other.

9. The expandable sheath according to claim 8, wherein the elongated sleeve comprises a lubricating layer or surface treatment between the tubular surface of the continuous elastomer outer layer and the outer surface of the expandable inner layer, the lubricating layer comprising at least one selected from the group consisting of silicone, glycerin oil, PTFE, or a hydrophilic polymer, for reducing the coefficient of friction.

10. The expandable inner layer is integrally formed from a substantially uniform rigid polymer material having notches or cutouts between the substantially cylindrical continuous portion and the discontinuous rigid polymer sheet portion, according to claim 9.

11. The retractable sheath according to claim 1, wherein the elongated sleeve is tapered at least partially along its longitudinal direction between the proximal opening and the distal opening.

12. The retractable sheath according to claim 11, wherein the edge of the elongated sleeve defining the distal opening has a circumference at least about 20% smaller than the edge of the elongated sleeve defining the circumference of the proximal opening.

13. The telescopic sheath according to claim 12, wherein the edge of the elongated sleeve defining the distal opening has a circumference at least about 25% smaller than the edge of the elongated sleeve defining the circumference of the proximal opening.

14. The retractable sheath according to claim 1, wherein the rigid polymer sheet is formed from a material comprising at least one selected from the group consisting of polyethylene, polypropylene, nylon, polyester, PTFE, copolymers thereof, or other biocompatible polymers.

15. The expandable sheath according to claim 1, wherein the continuous elastomer outer layer is made of an elastomer material, the continuous elastomer outer layer can expand when the elastomer material is stretched and can contract when the elastomer material is relaxed, and when the elastomer material contracts, it can return to a circumference of about 135% or less of the initial circumference.

16. The expandable sheath according to claim 15, wherein the continuous elastomer outer layer is expandable to approximately 1.35 times or more the circumference when the elastomer material is stretched.

17. The retractable sheath according to claim 1, wherein the continuous elastomer outer layer is formed from a silicone material or a silicone composite material and has a thickness of about 0.2 mm or less.

18. The retractable sheath according to claim 16, wherein the continuous elastomer outer layer has a thickness of approximately 0.1 mm.

19. The retractable sheath according to claim 1, further comprising a rigid introducer provided within the lumen of the elongated sleeve and protruding from the distal end of the elongated sleeve.

20. The retractable sheath according to claim 1, wherein the elongated sleeve is equipped with a radiopaque marker.

21. A method of using the retractable sheath described in claim 1, The steps of obtaining the retractable sheath described in claim 1, The steps include passing a rigid introducer through the lumen of the aforementioned retractable sheath, The process includes the step of introducing the aforementioned retractable sheath into a blood vessel. method.

22. A method for manufacturing the retractable sheath described in claim 1, The steps of obtaining the rigid collar, elastomer outer layer, and expandable inner layer described in claim 1, The steps include attaching the expandable inner layer to the rigid collar at the proximal opening, The step of placing the expandable inner layer inside the elastomer outer layer is included. method.

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