Hemostatic valve for sheath assembly

Abstract

An introducer sheath assembly for percutaneous delivery of a medical device that maintains hemostasis within a patient is provided. The assembly includes a hub, a hubcap, and a hemostatic valve. The introducer sheath assembly has a longitudinal axis and a lumen formed therein. The hemostatic valve includes a frame portion and a valve portion, the valve portion having a plurality of slits therein offset through a thickness of the valve portion, and an extension of the frame portion formed from a non-compressible material. When the valve is received by the hub, the extension of the frame portion is received by a valve positioning feature in the hub. The valve positioning feature also receives a positioning portion of the hubcap when the hub and hubcap are advanced into an engaged state, and the positioning portion of the hubcap is advanced into the valve positioning feature, thereby subjecting the non-compressible extension of the frame portion to a compressive force.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 62 / 935,300, filed November 14, 2019, which is incorporated by reference.

[0002] Technical Field The present invention relates to an introducer sheath assembly that allows for the introduction of a medical device into a patient's body at an insertion site, the introducer sheath assembly having a hemostatic valve for reducing or eliminating the drainage of bodily fluids from the patient through the insertion site of the introducer sheath assembly. [Background technology]

[0003] background Patients with heart disease are sometimes treated with a heart pump that is adapted to be inserted into the heart through an adjacent blood vessel and to supplement or replace the pumping function of the natural heart with a continuous pumping operation.

[0004] In one common approach, an introducer sheath is used to gain vascular access prior to the insertion of a medical device such as a heart pump. The introducer sheath is an assembly that includes a hemostatic valve; the hemostatic valve prevents blood leakage from the distal end of the introducer sheath during insertion into a blood vessel. The hemostatic valve should prevent excessive blood leakage when no object is present within the valve or when a guidewire, catheter, blood pump, or other object is being inserted through the valve. One of the main causes of excessive leakage in introducer sheaths is damage or perforation of the hemostatic valve. Summary of the Invention

[0005] overview Described herein is an introducer sheath assembly for percutaneously delivering a medical device that maintains hemostasis within a patient. As shown, the sheath assembly includes a sheath body and a sheath hub assembly coupled to the sheath body. The sheath hub assembly includes a hub, a hub cap, a hemostatic valve, and optionally, a foam. The hemostatic valve includes a valve portion and a frame portion. The frame portion defines a periphery of the valve and has a thickness greater than that of the valve portion, and the valve portion has a plurality of offset slits formed through the thickness of the valve portion. The valve thickness is in the direction in which the medical device moves through the valve. The valve is formed from an incompressible elastomer.

[0006] Examples of incompressible materials are natural rubber, synthetic rubber, polyisoprene, polyurethane, silicone, and thermoplastic elastomers, examples of which are styrenic block copolymers and thermoplastic vulcanizates.

[0007] Optionally, the hub may have a valve positioning feature formed therein. The valve positioning feature is adapted to receive the extension of the frame portion of the valve and the positioning portion of the hub cap. For example, the valve positioning feature may be configured as a channel having an inner wall with a first height and an outer wall with a second height, the outer wall being higher than the inner wall. In this configuration, the valve portion is located above the inner wall of the valve positioning feature, and the extension of the frame portion of the valve extends into the valve positioning feature.

[0008] Optionally, the hubcap's locating portion, i.e., the portion of the hubcap that locates within the hub's valve locating feature, may be thicker at its proximal end than at its distal end. The hubcap is secured in the assembly with the hub and valve. Optionally, the hubcap portion may be sonically welded to the hub portion.

[0009] Optionally, the hub may have a flush port formed therein. Flush ports in such devices are well known to those skilled in the art and will not be described in detail herein.

[0010] Optionally, the frame portion of the valve may have an O-ring at the distal end of the extension from the valve portion. Optionally, the frame portion extension may have a uniform thickness. In another optional configuration, the valve has frame extensions extending from both the proximal and distal sides of the valve body. In another configuration, the frame portion extensions are undercut extensions.

[0011] The locating portion of the hubcap may be either straight or tapered. If the locating portion is tapered, the taper may be either parallel or non-parallel to the tapered portion of the valve portion that contacts the locating portion when the hubcap is assembled to the valve and hub. If the locating portion is straight, it may be either parallel or non-parallel to the valve portion of the valve portion that contacts the locating portion when the hubcap is assembled to the valve and hub.

[0012] A method for assembling an introducer sheath is also described herein. In the method, a hub having a valve positioning feature formed therein is provided. A valve is also provided, comprising a valve portion and a frame portion, the frame portion being thicker than the valve portion. The valve is formed of an incompressible material having a plurality of spiral slits formed in the valve portion. The frame portion extends beyond the valve portion. A hub cap having a positioning portion is also provided. In the method, the valve is assembled to the hub. At least a portion of the frame portion is received by the valve positioning feature. A cap is assembled to the valve and hub such that at least a portion of the positioning portion of the hub cap is received in the valve positioning feature. The volume of the positioning portion received in the valve positioning portion deforms the incompressible material within the valve positioning feature. [Brief explanation of the drawings]

[0013] These and other objects and advantages will become apparent from the following detailed description considered in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout.

[0014] [Figure 1] 1 is a cross-sectional view of an introducer assembly having a hemostasis valve according to certain embodiments. [Figure 2] 3 illustrates percutaneous insertion of a heart pump using the hemostatic valve-utilizing introducer assembly of FIGS. 1 and 2. [Figure 3] 10 is a detailed cross-section of a hemostasis valve positioned within the hub. [Figure 4] FIG. 1 is a top view of a hemostasis valve according to one embodiment. [Figure 5] FIG. 10 is a bottom view of a hemostasis valve according to a second embodiment. [Figure 6] FIG. 5 is a top view of the hemostatic valve of FIG. 4. [Figure 7] 7A-7C are photographs of a hemostatic valve according to a first embodiment before and after insertion over a guidewire. [Figure 8] 8A-8D are photographs of a hemostatic valve according to the second embodiment before and after insertion over a guidewire. [Figure 9] FIG. 2 is a detailed view of a portion of the introducer assembly of FIG. 1. [Figure 10] 10A-10B illustrate compression of the valve as the hub cap is assembled onto the hub of the introducer assembly. [Figure 11] 11A-11B illustrate the introducer assembly before and after the hubcap is ultrasonically welded to the hub. [Figure 12] FIG. 7 is a cross-sectional view of the hemostatic valve shown in FIG. 6. [Figure 13] FIG. 13 is a cross-sectional view of the inner periphery of the hemostatic valve of FIG. 12. [Figure 14] FIG. 10 is a cross-sectional view of the outer periphery of a hemostasis valve according to a second embodiment. [Figure 15] FIG. 10 is a cross-sectional view of the outer periphery of a hemostasis valve according to a third embodiment. [Figure 16] A cross-sectional view of the outer periphery of a hemostatic valve based on a fourth embodiment. [Figure 17] 10 is an illustration of an alternative configuration of the hubcap that exerts pressure in two areas. DETAILED DESCRIPTION OF THE INVENTION

[0015] Detailed Description In this disclosure, when a given element is depicted in a particular drawing or a particular element number is considered or used, or referenced in corresponding descriptive material, it may encompass the same, equivalent, or similar element or element number identified in another drawing or descriptive material to which it pertains.

[0016] The use of " / " in the drawings or associated text is understood to mean "and / or" unless otherwise stated. The description of a particular numerical value or range of values, or use of terms such as approximately or about, is understood as including or describing the approximate numerical value or range of values ​​(e.g., within + / -2%, + / -5%, + / -10%, + / -15%, or + / -20%).

[0017] The term "set" as used herein corresponds to or is defined as a non-empty and finite organization of elements that exhibits a mathematical cardinality of at least 1 (i.e., a set as defined herein may correspond to a unit, singlet, or single-element set, or a multi-element set) based on known mathematical definitions (e.g., in a manner corresponding to the description in "Chapter 11: Properties of Finite Sets," An Introduction to Mathematical Reasoning: Numbers, Sets, and Functions, by Peter J. Eccles, Cambridge University Press (1998) (e.g., as described on p. 140)). Generally, the elements of a set may include or be part of a system, apparatus, device, structure, object, process, physical parameter, or value, depending on the type of set being considered.

[0018] As used herein, proximal is defined as toward or closer to the user, and distal is defined as farther from the user or in the direction away from or opposite distal with respect to fluid flow. The term "vessel" is taken to mean an anatomical vessel, passageway, or channel (e.g., a blood vessel such as an artery), or an anatomical chamber or compartment of a patient or subject. The term "perfusion" is taken to mean the infusion, transfer, or transmission of blood and / or one or more other fluids into a vessel for the purpose of allowing the blood and / or other fluids to reach an organ or tissue (e.g., to provide nutrients and oxygen thereto). The term "fluidically coupled" is taken to mean coupled in a manner that allows the transfer or transmission of fluids (e.g., liquids / gases).

[0019] Certain exemplary aspects will be described so that the systems, methods, and devices described herein can be fully understood. While the aspects and features described herein are specifically described for use in connection with an introducer sheath and hemostatic valve for percutaneously inserting a cardiac pump, it will be understood that all components and other features outlined below may be combined with one another in any suitable manner and may be adapted and applied to other types of introducer sheaths and hemostatic valves, or other types of cardiac assist devices, including balloon pumps.

[0020] The introducer sheath assemblies described herein have a hub / hubcap / valve assembly; the valve geometry and the hub geometry cooperate to seal two fluid paths, thereby providing a hemostatic introducer sheath assembly. The fluid paths independently sealed by the hub / hubcap / valve assembly are: 1) the fluid path around the valve, between the valve and the hub or hubcap, and 2) the fluid path through one or more slits in the valve that allow for the insertion of a medical device through the one or more slits in the valve and / or a mechanism for introducing such a medical device (e.g., a catheter; a dilator, etc.). The valve slits described herein cooperate with the hub / hubcap assembly to provide a hemostatic seal when closed and when a medical device is inserted therethrough.

[0021] Thus, an introducer sheath with a hemostatic valve and a hemostatic hub / hubcap / valve assembly provides two modes of sealing for the valve, which is advantageous compared to prior art assemblies that have only one sealing mode (compression). As compression increases through positioning of the hubcap within the hub, both modes of sealing increase. However, increasing compression increases the force required to insert a device through the valve. Therefore, the amount of force exerted on the valve by the hub / hubcap assembly is controlled so that the insertion force required to pass a device through the slit remains within an acceptable range.

[0022] The valve is formed from an incompressible material, such as silicone, natural or synthetic rubber, polyisoprene, polyurethane, and thermoplastic elastomer. Other incompressible materials suitable for use in the present invention are well known to those skilled in the art and will not be described in detail herein. The hub has a volumetrically constrained structure called a valve positioning feature. The valve has a frame portion with an extension that extends into the valve positioning feature when the valve is positioned in the hub. The hubcap has a positioning portion that also extends into the valve positioning feature when the hubcap is assembled onto the hub. This arrangement provides a volumetric interference between the incompressible valve frame extension, the valve positioning feature, and the positioning portion, thereby providing a sealing pressure between the frame portion extension (e.g., O-ring geometry) and the hub / hubcap. Because the incompressible valve frame extension fits within the valve positioning feature, the volume of the incompressible valve frame extension is smaller than the volume of the valve positioning feature into which it extends. When the hubcap locating portion is forced into the valve locating feature, it reduces the volume of the valve locating portion and deforms the incompressible valve frame extension, which seals off a potential fluid path between the valve and the hub / hubcap assembly.

[0023] The other fluid path through the slit in the valve is sealed by the introducer sheath assembly described herein. The hub / valve / hubcap assembly is dimensioned to provide a radial interference between the hubcap and the valve portion of the valve that provides sealing pressure on the surface of the slit formed in the valve portion. This radial interference is provided by the tapered geometry of the hubcap.

[0024] If the taper geometry of the hub cap is parallel to the corresponding taper on the valve, it will provide substantially uniform compression along the thickness of the valve portion. If the taper geometry is substantially non-parallel to the corresponding taper on the valve, it will provide substantially non-uniform compression along the thickness of the valve portion. In either instance, the compression at the distal end of the valve is greater than the proximal end of the valve.

[0025] Optionally, the hubcap may have a linear geometry. In this option, if the linear geometry of the hubcap is substantially parallel to the geometry of the valve, compression along the length of the valve portion is substantially uniform. If the linear geometry is substantially non-parallel to the geometry of the valve, substantially uneven compression is provided along the length of the valve portion. In either case, compression at the distal end of the valve is greater than compression at the proximal end of the valve.

[0026] In this manner, the systems, methods, and devices described herein reduce or eliminate the risk of bleeding during insertion of a medical device (e.g., a heart pump), guidewire, dilator, or other object. The present hemostatic valve and the manner in which it is disposed within the hub and hubcap control, reduce, or prevent blood loss through and around the valve.

[0027] The introducer sheath assembly has two primary functions. First, the introducer sheath creates a pathway into the desired vasculature to allow for device insertion and removal. Second, the introducer sheath must maintain hemostasis throughout the access site throughout the insertion process. A hemostatic valve maintains hemostasis through the lumen of the introducer sheath. The hemostatic valve component is typically located in the proximal-most portion of the introducer sheath, known as the hub.

[0028] The hemostatic valve is required to form a seal when assembled into the hub. The hemostatic valve must maintain this seal when a device of any size is inserted therethrough. As described above, the hub and hub cap assembly exerts a force on the hemostatic valve described herein to prevent fluid flow from the distal end through the proximal end of the sheath assembly (i.e., leakage from the sheath assembly insertion site).

[0029] To ensure that the valve maintains its seal when a device is threaded through the valve, the additional radial compression applied to the valve by the hub / hubcap assembly ensures that the seal is not compromised by changes in the diameter of the inserted device. In the case of the valve / hub / hubcap assemblies described herein, this additional radial compression is provided by placing the valve within the hubcap. The hub and hubcap assembly is configured to act on the elastomeric valve to provide the necessary valve compression. The valve has a downward-facing sidewall thickness that cooperates with the hubcap fitted within the hub to form the desired seal. Optionally, the downward-facing sidewall of the valve may terminate in an O-ring. Inserting the hubcap downward into the hub applies a compressive force to the slitted valve, sealing it. Optionally, the hubcap may have a tapered opening so that the diameter of the interior of the hubcap that receives the valve decreases as the hubcap advances into the hub. This tapered diameter is referred to herein as the compression feature.

[0030] For an introducer sheath to be able to accommodate devices having multiple diameters, such as the blood pumps described herein, it must form a seal with devices having a variety of diameters, such as 9 French (3 mm), 10 French (3.33 mm), 11 French (3.67 mm), 12 French (4 mm), 13 French (4.33 mm), 14 French (4.67 mm), 15 French (5 mm), 16 French (5.33 mm), 17 French (5.67 mm), 18 French (6 mm), 19 French (6.33 mm), 20 French (6.67 mm), 21 French (7 mm), or any other suitable diameter. Blood pump devices that can be inserted through the introducer sheath assemblies described herein are described, for example, in U.S. Patent No. 7,736,296 to Seiss et al., entitled "Intercardiac Blood Pump," which is incorporated herein by reference.

[0031] For blood pump insertion, the valve must be able to maintain a seal under the following conditions: i) sheath only (when there is nothing inside the valve); ii) only the dilator is inserted into the valve (the dilator may be silicone coated and inserted into the valve to lubricate the valve before inserting the pump device through the valve); iii) a first guidewire is inserted into the valve (e.g., a 0.035" (0.889 mm) diameter guidewire is threaded through the hemostatic valve and used to advance the pump through the valve); iv) A 6 Fr guide catheter is inserted through the valve; v) a second guidewire is inserted into the valve (e.g., a 0.018" (0.457 mm) diameter guidewire); vi) the second guidewire in v), but inserted into the valve along with the 9 Fr catheter portion (3 mm) of the pump; and vii) Pump device (9 Fr (3 mm) catheter portion).

[0032] The above conditions are listed by way of example and not limitation. The assemblies described herein solve the problems of hemostasis and minimal insertion and removal forces while maintaining ease of manufacture of the hub, hubcap, and valve itself. The assemblies described herein provide hemostasis for each of the various sized devices inserted through the valve. The seal is also maintained when such devices are removed.

[0033] The valves described herein are constructed as thin (e.g., about 2 mm to about 4 mm) discs received within a hub / hubcap assembly. The valve is circular because the hub / hubcap assembly defines an internal lumen with a circular cross-section through which the device is inserted into the patient. The valve may be made of soft silicone; a flexible polymer, such as natural or synthetic rubber, polyisoprene, or polyurethane; or a thermoplastic elastomer, such as a styrenic block copolymer or a thermoplastic vulcanizate. The disc has first and second thicknesses. The first peripheral thickness exceeds the second internal thickness. The thicker peripheral portion of the disc is referred to as the frame portion, and the thinner internal portion is referred to as the valve portion. Accordingly, the first thickness is referred to herein as the frame thickness, and the second thickness is referred to as the valve thickness. Both thicknesses are measured in the axial direction of the introducer sheath assembly. Referring to FIG. 12, a valve 104, shown in cross section, has a frame portion 123, shown in FIG. 1, extending from a peripheral portion 123 and terminating in an O-ring portion 120 above the O-ring portion 120. Valve 104 has a valve portion 124 that is thinner than frame portion 123. The O-ring is made of an incompressible material, such as materials described elsewhere herein. O-ring portion 120 defines inner and outer circumferences over which thinner valve portion 124 extends. An internal void portion is designated 125. As described elsewhere herein, O-ring 120 is optional. As described herein, O-ring 120 is an example of an incompressible feature described herein.

[0034] FIG. 1 is a cross-sectional view of an introducer sheath assembly 100 including a hemostatic valve 104 disposed within a hub 102 having a hub cap 105 assembled thereon. The hub has an internal cavity 109 that receives the hemostatic valve 104 and tapers to an internal lumen 111. The hemostatic valve has a valve portion 124 that is thinner than a frame portion 123. The hub 102 is also assembled to an elongate introducer body 106 (i.e., sheath) having an internal lumen 107 and a longitudinal axis 108. The internal lumen 111 of the hub is fluidly connected to the internal lumen 107 of the elongate introducer body. The introducer assembly may optionally include a lubricating foam 110. The lubricating foam actively lubricates a device inserted therethrough. Suitable lubricating foams are well known to those skilled in the art and will not be described in detail herein. Optionally, the lubricating foam 110 may be an open-cell polyurethane that absorbs and retains a lubricating fluid, such as silicone oil. The foam 110 has attachment features to a cap to hold the foam in place. Such attachment features are known and therefore not illustrated herein. The foam 110 has through-holes 127 for devices to pass through so that the device is passively lubricated by the silicone oil within the open-cell network. Optionally, the foam may be provided in portions and assembled with the valve 104 when the hubcap 105 is placed on top.

[0035] The hub 102 has an inlet 153 (i.e., flush port) that fluidly connects a fluid supply line 152 to the internal lumen 111 of the hub 102. Arrows 154 indicate the flow path for fluid entering the hub 102 through the inlet 153. When the hubcap 105 is fully positioned within the hub 102, the hubcap 104 and hub 102 combine to deform the O-ring (the O-ring is incompressible, so its volume does not change). This force 155 seals a potential fluid path within a valve region 156 between the valve 104 and the hub 102 / hubcap 105. The hubcap 105 also exerts a compressive force 157 on the valve 104. The compressive force 157 seals the valve 104 within the hub 102 / hubcap 105 so that there is no fluid flow through the valve 104 from the internal lumen 111 of the hub 102. As shown in Figure 1, a peripheral portion 124 of the valve 104 terminates in an O-ring 120. Figure 1 illustrates the O-ring 120 in an undeformed state and illustrates the change in dimensions of the valve 104 and its O-ring portion 120 caused by fully positioning the hub cap 105 onto the hub 102.

[0036] FIG. 2 illustrates percutaneous insertion of a heart pump assembly 200 using the introducer sheath assembly 100 with the hemostatic valve 104 of FIG. 1 . The heart pump assembly 200 includes a distal end portion 203 including an outlet 206 and a delivery catheter 202. The introducer sheath assembly 100 is shown as also including a fluid supply line 152 for a flush port 153. The fluid supply line has a valve (not shown) used to turn on and off the flow of fluid into the introducer sheath assembly. The fluid supply line 152 may be used to flush the introducer sheath assembly 100 before, during, or after insertion of the heart pump assembly 200. The distal end portion 203 of the heart pump assembly 200 is inserted into the valve assembly 100 along an insertion path 204.

[0037] FIG. 3 illustrates a spiral slit 126 formed through the thickness of the valve portion 124 of the valve 104. Such slits are described in WO2019090351 to Korkuch et al., which is commonly owned with the present application and is incorporated herein by reference. As used herein, a spiral slit is a slit in which cuts in the material are offset through the thickness of the valve portion. For example, the cut 126 may form a spiral through the thickness of the valve portion. The cut may be a single cut or multiple cuts. Such slits are well known to those skilled in the art and will not be described in detail herein.

[0038] The spiral slit 126 passes through the thickness of the valve portion 124 and across the center of the valve. The spiral slit 126 follows a spiral path through the thickness of the valve portion 124 from line 126A ( FIG. 6 ) on the upper surface of the valve 124 to line 126B ( FIG. 5 ) on the lower surface of the valve. The lengths of the first group of lines 126A and the second group of lines 126B determine the size of the spiral slit 126. The size of the spiral slit 126 may be set to balance hemostatic performance with the insertion and removal force of a medical device inserted through the hemostatic valve 104. As the lengths of the first group of lines 126A and the second group of lines 126B increase, the size of the spiral slit 126 increases, reducing the hemostatic performance of the hemostatic valve 104 and also reducing the removal force of a medical device inserted through the hemostatic valve 104.

[0039] As depicted in FIG. 4 , the angle α of the spiral slit 126 defines the angular path of the spiral slit 126 as it traverses through the thickness of the valve 124. Generally, α can be any angle that matches the angular offset between a first set of lines 126A on the upper surface of the valve portion 124 and a second set of lines 126B on the lower surface of the valve portion 124. In another aspect, the angle α matches the angular offset of two of the spiral slits 126 on the upper surface of the valve portion 124. In some aspects, α is equal to 360 / n, where n is the number of spiral slits 126. In another aspect, α is unrelated to the angular offset of two of the lines 126A on the upper surface of the valve portion. In this case, α is the angle of rotation of the helix between the upper and lower surfaces of the valve portion 124 and does not necessarily correspond to the angle between the two lines 126A; as such, the first set of lines 126A and the second set of lines 126B may be angularly offset from one another. This is illustrated in FIG. 6.

[0040] The valve 104 is shown as being received within the hub 102. The hub 102 defines a groove or channel 136 that receives the frame portion 123 of the valve 104, including the O-ring 120 of the valve 104, as shown in FIG. 3 . The channel 136 forms a valve positioning feature 137 having an inner channel wall height 132 and an outer channel wall height 134. The valve portion 124 is supported within the hub 102 by the inner channel wall 130. To assemble the hub 102, valve 104, and hub cap 105, the valve 104 is first placed within the hub 102. When the O-ring 120 is received within the valve positioning feature 137 in the hub 102, it stretches slightly over the inner channel wall 132. However, the O-ring 120 is not compressed when inserted into the hub 102. The potential for fluid leakage through the distal end of the introducer sheath assembly is reduced or eliminated by coupling the hub cap 105 to the hub 102 .

[0041] As described above, the non-compressible feature (e.g., O-ring 120) is a frame portion 123 extending from the valve portion 124. The frame portion has an inner circumference and an outer circumference and is received by the valve positioning feature 137. The inner diameter of the valve positioning feature 137 exceeds the diameter of the internal lumen 111. Because the non-compressible portion is received within the valve positioning feature 137 and the inner diameter defined by the non-compressible feature 120 is larger than the internal lumen, the non-compressible feature 120 does not contact or otherwise engage with devices passing through the spiral slit 126 and the internal lumen 111 of the introducer sheath assembly 100.

[0042] FIG. 4 is a top view of valve 104, in which valve portion 124 has helical slit 126A, depicted as a series of offset cuts, disposed therein. O-ring 120 is disposed below valve portion 124 but has both an inner diameter and an outer diameter that extend beyond the outer diameter of valve portion 124. Valve 104 may be formed as a monolithic piece by injection molding or other molding techniques, which allows the valve design and configuration to be reproduced within very close tolerances. In addition to radial compression of valve 104 by hub 102 and hub cap 105 of introducer sheath assembly 100 when a device (not shown) is threaded through helical slit 126A, hemostasis is also achieved through the design of the helical slit / cut.

[0043] Figure 5 is a top down view of the valve 104. The valve is slightly recessed upward from the O-ring 120 to the valve portion 124, which has a spiral slit 126B formed therein. Figure 5 illustrates optional valve slit 126B configurations, varying from a three-cut spiral to a two-cut configuration. While the two-cut configuration does not reflect the spiral, the spiral propagates through the thickness of the valve portion 124.

[0044] The hemostatic valve 104 may optionally be made of soft silicone. Durometer values ​​(i.e., Shore A hardness) of 20A, 30A, and 40A are expected to be suitable. The valve may also be made of an entirely different elastomer that exhibits similar properties, such as a lower durometer. Examples of such materials are natural or synthetic rubber, polyisoprene, polyurethane, or thermoplastic elastomers such as styrenic block copolymers or thermoplastic vulcanizates. Optionally, the hemostatic valve 104 may be made of medical-grade silicone or other elastomers.

[0045] Figure 6 illustrates the valve of Figure 4, but with a spiral cut progressing through valve portion 124. Figure 6 also illustrates that the diameter of the valve portion tapers slightly inward from the distal end to the proximal end. A cross-section of the valve illustrated in Figure 6, taken along line 12-12, is illustrated in Figure 12.

[0046] 7A-7C are photographs of a hemostatic valve 104 with a spiral slit 126 formed in an x-shape. FIG. 7A shows the valve 104 before anything has been inserted through the slit 126. FIG. 7B shows the valve 104 after a guidewire 134 has been inserted through it. FIG. 7C is a close-up of the slit 126 being compromised by the guidewire 134. Note that in FIG. 7B, there is a gap 136 through the valve 104 that forms when the guidewire is pulled slightly off-center. Typically, a device is inserted after the guidewire has been successfully threaded through the introducer sheath assembly 100. FIG. 7C is a close-up of the gap formed in the valve depicted in FIG. 7B.

[0047] Figures 8A-8D are photographs of a hemostatic valve 104 with a spiral slit 126. The spiral slit propagates through the thickness of the valve portion 124 of the hemostatic valve 104. In Figure 8B, the slit 126 in the valve has been indented to show the spiral nature of the spiral slit 126 (i.e., the offset of the cut as it progresses through the thickness of the valve portion 124). Figure 8C is an image of the valve 104 with a guidewire 134 passing through the slit 126. Figure 8D shows the valve 104 when the guidewire 134 passing through the slit 126 has been pulled off-center.

[0048] Referring to Figure 9, a detailed cross-sectional view of the introducer sheath assembly 100 is shown with the hubcap 105 mating with the hub 102, thereby compressing the frame portion 123 of the hemostatic valve 104 within the valve positioning feature 137. The hubcap 105 has a positioning portion 141 that is pressed into the valve positioning feature 137 between the inner wall 132 and the outer wall 134 of the channel 136 of the hub 102. The relaxed state of the O-ring portion 120 is shown in phantom in Figure 9. Because the O-ring portion 120 is made of a non-compressible material, when the positioning portion 141 of the hubcap 105 is placed within the valve positioning feature 137, the volume available for the O-ring therein is reduced. Because of that reduced volume, the O-ring portion 120 exerts a force that substantially seals the fluid path between the valve, the hub, and the hubcap.

[0049] 17 , hubcap 105 has a stepped interior portion that provides a targeted lateral deformation to valve portion 124 and O-ring portion 120. Stepped portion 160 is sized to exert a lateral force 163 on O-ring 120 when hubcap 105 is positioned on hub 102. Stepped portion 162 is sized to exert a lateral force 163 on valve portion 124 (which has a vertical peripheral profile that is recessed laterally relative to the vertical peripheral profile of O-ring 120). Phantom line 164 illustrates the profiles of valve portion 124 and O-ring 120 prior to deformation by stepped portions 162 and 160, respectively. When hubcap 105 is fully positioned on hub 102, the stepped portions comply with the constraints imposed by stepped portions 160, 162 of hubcap 105.

[0050] 10A-10B, the hub cap 105 is illustrated as having a compression feature 140. The cap 105 with the compression feature 140 is illustrated in FIG. 10A. The compression feature 140 is illustrated as an inwardly and downwardly tapering surface on the portion of the hub cap 105 in which the valve portion 124 of the valve 104 is received. The compression feature 140 seals a slit in the valve portion 124 through the thickness of the valve portion 124. Optionally, the compression feature may be linear. If the compression feature is linear, the slit is sealed across the lateral extent of the valve portion 124. As can be seen from line 142 in FIG. 10B, the frame portion 123 of the valve 104 is compressed inward by the compression feature 140. As discussed above, the compression feature mitigates leakage from the distal end of the introducer sheath assembly 100 that might otherwise occur through a slit in the valve 104. As mentioned above, the introducer sheath assemblies described herein mitigate leakage through two different paths; one through the valve 104 and the other around the valve 104.

[0051] 11A-11B illustrate the hubcap 105 being advanced into the hub 102 for engagement between the hubcap 105 and the hub 102. In FIG. 11B, the valve profile before the hubcap is placed into the hub is shown in solid lines, and the profile after the hubcap is inserted is shown in dashed lines. Referring to FIG. 11A, the hubcap 105 is positioned above the hub 102 and valve 104; the valve 104 is positioned within the hub 102 before the hubcap 105 is placed thereon. The valve has a thinner valve portion 124 and a thicker frame portion 123. The valve O-ring 120 rests within the valve locating feature 136. Foam 110 extends downward from the hubcap 105. The locating portion 141 of the hubcap 105 extends into the valve locating feature 137.

[0052] Referring to FIG. 11B, the hubcap 105 and hub 102 are brought into contact with one another. As described above, forcing the hubcap 105 into the valve positioning feature 137 deforms the incompressible O-ring 120, which seals off any potential fluid path between the valve 104 and the hub 102 / hubcap 105. The valve portion 124 stretches slightly over the valve positioning feature 137 within the hub 102, but is not compressed until the positioning portion 141 of the hubcap 105 is pressed downward onto the hub 102. The positioning portion of the hubcap 105 compresses the O-ring 120 within the valve positioning feature 137 of the hub 102. The O-ring 120 is not fully compressed until the hubcap 105 is fully positioned on the hub (e.g., the hubcap 105 is ultrasonically welded to the hub 102). The ultrasonic weld is illustrated as 150 in FIG. 11B.

[0053] The foam 110 in the hubcap 105 may be formed as pins (not shown) that help the hubcap 105 engage the valve 104. To reduce friction or insertion forces between the valve 104 and a device inserted therethrough, the valve 104 is either formed from or coated with silicone.

[0054] 12 is a cutaway view of the valve 104 shown in FIG. 6, illustrating a cross section of the valve 104 from inside the valve such that a portion of the O-ring 120 is visible along the valve portion 124 above the O-ring. Cavity 125 is the portion of the valve interior defined by frame portion 123 and valve portion 124.

[0055] Figure 13 is a side view of the hemostatic valve 104 of Figure 12. The O-ring 120 is shown in phantom in this view, as it is located on the inner periphery of the valve portion and is therefore viewed from the outer periphery of the valve. The spiral slit 126 is also shown in phantom. The spiral slit 126 is formed through the thickness of the valve portion 124.

[0056] Figure 14 is an alternative hemostatic valve configuration 304, also shown in cross section as in Figure 12. In this configuration, the O-ring is replaced with a linear extension 320 of the frame portion 323 of the valve 304. In this embodiment, the extension 320 is a non-compressible feature that experiences a compressive force within the valve positioning feature 137 when the hub cap 105 is assembled to the hub 102. The valve portion 324 has a spiral slit (not shown) formed therethrough. The extension 320 extends below the valve portion 324 and alternatively performs the function of the O-ring described in the previous embodiment. The frame portion 323 and the valve portion 324 define a cavity 325 below the valve portion 324.

[0057] Figure 15 is an alternative hemostatic valve configuration 404. In this configuration, the O-ring is replaced with an extension 420 on the frame portion 423 that is squared off instead of the rounded O-ring structure. The undercut extension 420 is also received by the valve positioning feature of the hub (not shown in Figure 14) and is a non-compressible feature of the valve 404. The valve portion 424 also has a spiral slit (not shown) formed therethrough. The frame portion 423 and the valve portion 424 define a void 425 below the valve portion 424.

[0058] 16 illustrates an alternative hemostatic valve configuration 504. This hemostatic valve 504 has a frame portion 523 with two extension portions 520 and 520′. The non-compressible feature 520′ is received by the valve positioning feature, while 520 also anchors the hemostatic valve 504 within the introducer sheath assembly when the device is removed from the introducer sheath assembly. A spiral slit is formed in a valve portion 524 intermediate the two extension portions 520 and 520′ of the frame portion 523 of the valve 504. The valve 504 has two voids defined by the valve portion 524 and the frame portion 523. One void 525 is above the valve portion 524, and the other void 525 is below the valve portion 524.

[0059] In this specification, the word "comprising" is to be understood in its "open" sense, i.e., the sense of "including," and therefore is not limited to its "closed" sense, i.e., the sense of "consisting only of." Where the corresponding words "comprise," "comprised," and "comprises" appear, corresponding meanings should be considered to be those of those words.

[0060] While specific aspects of the present technology have been described, it will be apparent to those skilled in the art that the technology may be embodied in other specific forms without departing from its essential characteristics. Accordingly, the described aspects and examples are to be considered in all respects as illustrative and not restrictive. It should be understood that the introducer assemblies described herein may be applied to other systems in which it is desirable to access an arteriotomy in a patient while maintaining hemostasis. Variations and modifications will occur to those skilled in the art after reviewing this disclosure. The features of the present disclosure may be implemented in any combination and subcombination (including multiple subsidiary combinations and subcombinations) with one or more other features.

[0061] It should be further understood that reference herein to material known in the art does not constitute an admission that such material is generally known by those of ordinary skill in the relevant art(s) of this technology, unless otherwise indicated.

Claims

1. An introducer sheath assembly for percutaneous delivery of a medical device to maintain hemostasis within the patient's body, Sheath body; and The sheath hub assembly, connected to the sheath body, comprises a hub, a hub cap, a hemostatic valve, and a valve positioning portion. The hemostatic valve comprises a valve portion and a frame portion, The valve portion is equipped with a helical slit, The hemostatic valve is an introducer sheath assembly comprising at least one void defined by the frame portion of the hemostatic valve.

2. The introducer sheath assembly according to claim 1, wherein the at least one void comprises a lower void and an upper void, each defined by the frame portion, and the valve portion is sandwiched between the lower void and the upper void.

3. The introducer sheath assembly according to claim 2, wherein the frame portion further comprises an O-ring portion configured to be received by the valve positioning portion.

4. The introducer sheath assembly according to claim 1, wherein the frame portion comprises a linear extension.

5. The introducer sheath assembly according to claim 4, wherein the valve positioning portion is configured to receive the linear extension, and the linear extension extends below the valve portion.

6. The introducer sheath assembly according to claim 1, wherein the frame portion comprises a square extension portion that forms an undercut extension portion configured to be received by the valve positioning portion.

7. The introducer sheath assembly according to claim 6, wherein the at least one gap defined by a portion of the hemostatic valve comprises a gap below the valve portion defined by the frame portion and the valve portion.

8. The introducer sheath assembly according to claim 1, wherein the frame portion comprises a first extension portion and a second extension portion.

9. The introducer sheath assembly according to claim 8, wherein the first extension is configured to anchor the hemostatic valve within the introducer sheath assembly.

10. The introducer sheath assembly according to claim 8, wherein the second extension portion is configured to be received by the valve positioning portion.

11. The introducer sheath assembly according to claim 8, wherein the at least one void comprises a first void defined by a first space above the valve portion and a second void defined by a second space below the frame portion.

12. The introducer sheath assembly according to claim 11, wherein the helical slit is formed in the valve portion located midway between the first extension portion and the second extension portion.

13. The introducer sheath assembly according to claim 1, wherein the sheath hub assembly further comprises a lubricating foam.

14. The introducer sheath assembly according to claim 1, wherein the hemostatic valve is formed from an incompressible elastomer.

15. The introducer sheath assembly according to claim 14, wherein the incompressible elastomer is selected from the group consisting of natural rubber, synthetic rubber, polyisoprene, polyurethane, silicone, and thermoplastic elastomers.

16. The introducer sheath assembly according to claim 15, wherein the thermoplastic elastomer is one of a styrene-based block copolymer or a thermoplastic vulcanized product.

17. The introducer sheath assembly according to claim 1, wherein the hub cap includes a lubricating foam.

18. The introducer sheath assembly according to claim 1, wherein the hub has a flash port formed therein.

19. The introducer sheath assembly according to claim 1, wherein the helical slit has an x-shaped pattern.

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