Introducer sheath with multi-layered hub - Patent application

Abstract

To provide an introducer sheath having a multi-layer hub for percutaneous insertion of a heart pump.SOLUTION: An introducer assembly includes an elongate sheath sized for insertion into a blood vessel of a patient, and a hub. The hub can be coupled to a proximal portion of the sheath and can include a first hub portion and a second hub portion. The hub can include various features to facilitate breaking away or separating the introducer assembly from a patient. For example, the first hub portion can have a first notch which can facilitate breaking, splitting, or fracturing the hub. The second hub portion can partially surround the first hub portion and can include two wings and an opening disposed above the first notch. The first hub portion can be formed from a first material, and the second hub portion can be formed from a second material. In some embodiments, the second material can be stiffer than the first material to facilitate fracturing the hub.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 62 / 298,171, filed on February 22, 2016, the content of which is incorporated herein by reference in its entirety.

Background Art

[0002] Background Patients with heart disease may be treated with a percutaneous mechanical circulatory support device, commonly referred to as a heart pump, configured to assist the native heart pump function or replace the native heart pump function by continuous pumping operation. Such a heart pump assembly can be introduced surgically or percutaneously through the vasculature, for example through a blood vessel, during a heart procedure. In one common approach, the pump assembly is inserted by a catheter insertion procedure through the femoral artery using an introducer sheath.

[0003] The introducer sheath can provide a reliable access point for the introduction of a heart pump assembly as well as a wide range of diagnostic and therapeutic intervention catheter - based devices. The introducer sheath can be inserted into an artery or a vein, and the pump can be advanced through the introducer sheath into the patient. Then, the introducer sheath can be cut and peeled away into two halves along a break wall, leaving the pump, catheter, and / or guide wire in place. This allows a physician to perform clinical procedures that require separation / removal of the introducer sheath without disturbing the position of the pump, catheter, guide wire, and / or other devices that are to be introduced into and remain within the body.

[0004] As percutaneous heart pumps have become larger and more sophisticated, the introducer sheaths used to introduce the pump into the body have necessarily become larger as well. Larger introducer sheath-hub assemblies require a greater break force to split the introducer sheath hub (e.g., due to a greater break wall thickness). The increased break force can make hub rupture more difficult and less reliable. Furthermore, the increased break force can lead to abrupt hub rupture, which can unnecessarily shake, dislodge, or damage the pump and / or potentially cause discomfort or injury to the treating physician. Summary of the Invention

[0005] overview Disclosed herein is an introducer sheath having a multi-layered hub for percutaneous insertion of a heart pump. The hub can include two or more hub sections formed of different materials to reduce the breakage force required to split a tear-away introducer. The hub includes a first hub section and a second hub section partially surrounding the first hub section. The first hub section includes one or more notches along which the hub is configured to split. The second hub section includes wings or tabs located on each side of the hub to provide leverage for applying the breakage force. The first hub section can be formed of a soft material with low ultimate strength, while the second hub section can be formed of a relatively rigid material with an ultimate strength greater than that of the first hub section. In such a configuration, the soft first hub section allows the hub to easily split along the notches in the first material, while the rigid second hub section has rigid wings that provide improved leverage during fracture. The stiff wings do not bend or flex excessively when force is applied, but instead transfer the applied load to the notch, thereby facilitating the splitting of the introducer. The stiffer wings also reduce the amount of elastic energy stored when force is applied to the wings during splitting of the introducer hub. This reduces the sudden release of elastic energy when the hub splits, thereby reducing the risk of displacing or damaging the pump or causing discomfort or injury to the patient or physician. Thus, by using two hub sections with different material properties, the systems, methods, and devices described herein can facilitate the splitting of tear-away introducer sheaths. By maintaining a low break force, the multi-layered hub allows for the use of larger-diameter introducer sheaths that would otherwise be unable to split.

[0006] The second hub portion can be overmolded onto the first hub portion. The overmolding can form a hemostatic bond between the first hub portion and the second hub portion. To strengthen the bond between the two portions, the first hub portion can also include ridges or grooves, and the second hub portion is molded over these ridges or grooves. This can increase the amount of torque that the second hub portion can transmit to the first hub portion without breaking the bond. Additionally, the second hub portion can include an opening over one or more notches of the first hub portion. This opening allows the first hub portion to crack easily in the region of the one or more notches, thereby preserving the low breaking force of the hub.

[0007] In one aspect, the introducer assembly includes an elongate sheath and a hub. The elongate sheath is sized for insertion into a patient's blood vessel and includes a longitudinal axis. The hub is coupled to the proximal portion of the sheath and includes a first hub portion and a second hub portion. The first hub portion includes a first notch. The second hub portion partially surrounds the first hub portion and includes two wings and an opening provided over the first notch. The first hub portion includes a first material, the second hub portion includes a second material, and the first material is different from the second material. In some embodiments, the first material has a first ultimate strength and the second material has a second ultimate strength. In certain embodiments, the second ultimate strength is greater than the first ultimate strength. In some embodiments, the first material has a first rigidity and the second material has a second rigidity, and the second rigidity is greater than the first rigidity.

[0008] In some embodiments, the first notch is oriented parallel to the longitudinal axis of the elongate sheath. In certain embodiments, the hub is configured to break at the first notch along the direction of the longitudinal axis of the elongate sheath. In some embodiments, the elongate sheath has a longitudinal cut parallel to the longitudinal axis of the elongate sheath. The elongate sheath can be configured to tear along the longitudinal cut parallel to the longitudinal axis of the elongate sheath.

[0009] In some embodiments, the first hub portion includes a ridge. In some embodiments, the first hub portion and the elongate sheath form a hemostatic bond. In certain embodiments, the wings include a wide side and a narrow side, the wide side being perpendicular to the longitudinal axis of the elongate sheath. In some embodiments, the narrow side of the wings is perpendicular to the longitudinal axis of the elongate sheath. In some embodiments, the first hub portion further includes a second notch. In some embodiments, the first hub portion includes a first ridge and a second ridge that define edges of the first notch.

[0010] In some embodiments, the first material has a hardness of about 45 Shore D. In certain embodiments, the second material has a hardness of about 68-72 Shore D. In some embodiments, the introducer hub has a minimum diameter of about 9 Fr. In other embodiments, the introducer hub has a minimum diameter of about 26 Fr. In certain embodiments, the first hub portion has a minimum thickness of about 0.1 mm at the first notch. In some embodiments, the first hub portion has a maximum thickness of about 0.3 mm at the first notch.

[0011] In some embodiments, the thickness of the first hub portion at the first notch is variable along the length of the notch. In some embodiments, the thickness of the first hub portion at the first notch is greatest at the proximal end portion of the first notch. In some embodiments, the thickness of the first hub portion at the first notch is between about 0.01 inches and 0.012 inches at the proximal end of the first hub. In some embodiments, the thickness of the first hub portion at the first notch is between about 0.004 inches and 0.006 inches at the distal end portion of the first hub. [The present invention 1001] an elongated sheath having a longitudinal axis, the sheath being sized for insertion into a patient's blood vessel; a hub coupled to a proximal portion of the sheath; the hub comprising: a first hub portion having a first notch; a second hub portion partially surrounding the first hub portion; and wherein the second hub portion comprises: With two wings; an opening provided above the first notch; the first hub portion comprises a first material and the second hub portion comprises a second material, the first material being different from the second material; Introducer assembly. [The present invention 1002] The introducer assembly of the present invention 1001, wherein a first material has a first ultimate strength and a second material has a second ultimate strength, the second ultimate strength being greater than the first ultimate strength. [The present invention 1003] The introducer assembly of the present invention 1001, wherein the first material has a first stiffness and the second material has a second stiffness, the second stiffness being greater than the first stiffness. [The present invention 1004] The introducer assembly of any one of claims 1001 to 1003, wherein the first notch is oriented parallel to the longitudinal axis of the elongate sheath. [The present invention 1005] The introducer assembly of any one of claims 1001 to 1004, wherein the hub is configured to break at a first notch along the longitudinal axis of the elongate sheath. [The present invention 1006] The introducer hub of any one of inventions 1001 to 1005, wherein the elongated sheath includes a longitudinal cut parallel to the longitudinal axis of the elongated sheath. [The present invention 1007] The introducer assembly of any one of claims 1001 to 1006, wherein the elongate sheath is configured to split along a longitudinal incision parallel to the longitudinal axis of the elongate sheath. [The present invention 1008] The introducer assembly of any one of inventions 1001 to 1007, wherein the first hub portion includes a ridge. [The present invention 1009] An introducer assembly according to any one of inventions 1001 to 1008, wherein a first hub portion and an elongated sheath form a hemostatic bond. [Invention 1010] An introducer assembly according to any one of inventions 1001 to 1009, wherein each wing includes a wide surface and a narrow surface, and the wide surface is perpendicular to the longitudinal axis of the elongated sheath. [Invention 1011] An introducer assembly according to any one of inventions 1001 to 1010, wherein each wing includes a wide surface and a narrow surface, and the narrow surface is perpendicular to the longitudinal axis of the elongated sheath. [Invention 1012] An introducer assembly according to any one of inventions 1001 to 1011, wherein the first hub portion includes a second notch. [Invention 1013] An introducer assembly according to any one of inventions 1001 to 1012, wherein the first hub portion includes a first ridge and a second ridge that define an edge of the first notch. [Invention 1014] An introducer assembly according to any one of inventions 1001 to 1013, wherein the first material has a hardness of about 45 Shore D. [Invention 1015] An introducer assembly according to any one of inventions 1001 to 1014, wherein the second material has a hardness in the range of about 68 to 72 Shore D. [Invention 1016] An introducer assembly according to any one of inventions 1001 to 1015, wherein the hub has a minimum diameter of about 9 Fr. [Invention 1017] An introducer assembly according to any one of inventions 1001 to 1016, wherein the hub has a minimum diameter of about 26 Fr. [Invention 1018] An introducer assembly according to any one of inventions 1001 to 1017, wherein the first hub portion has a minimum thickness of 0.1 mm at the first notch. [Invention 1019] The introducer assembly of any of the present inventions 1001 - 1018, wherein the first hub portion has a maximum thickness of 0.3 mm at the first notch. [The present invention 1020] The introducer assembly of any of the present inventions 1001 - 1019, wherein the thickness of the first hub portion at the first notch is variable along the length of the notch. [The present invention 1021] The introducer assembly of the present invention 1020, wherein the thickness of the first hub portion at the first notch is maximum at the proximal end portion of the first hub portion. [The present invention 1022] The introducer assembly of the present invention 1021, wherein the thickness of the first hub portion at the first notch is about 0.01 inch to 0.012 inch at the proximal end portion of the first hub portion. [The present invention 1023] The introducer assembly of the present invention 1021, wherein the thickness of the first hub portion at the first notch is about 0.004 inch to 0.006 inch at the distal end portion of the first hub portion.

Brief Description of the Drawings

[0012] The foregoing and other objects and advantages will become apparent from the following detailed description when considered in conjunction with the accompanying drawings. In the figures, like reference numerals throughout refer to like parts.

[0013] [Figure 1] A plan view of an exemplary introducer hub assembly is shown. [Figure 2] A perspective view of an exemplary introducer hub assembly is shown. [Figure 3] A perspective view of an exemplary first hub portion of an introducer hub assembly is shown. [Figure 4] A perspective view of an introducer hub assembly including first and second hub portions is shown. [Figure 5] A perspective view of the notch of the introducer hub assembly of FIG. 2 is shown. [Figure 6]Shows an end view of an exemplary introducer hub assembly having a plurality of material layers. [Figure 7] Shows a perspective view of an exemplary introducer hub assembly having wings disposed laterally with respect to the central longitudinal axis of the introducer hub. [Figure 8] Shows an introducer hub assembly inserted into a patient's blood vessel, together with a percutaneous pump extending therethrough. **DETAILED DESCRIPTION**

[0014] Detailed Description To provide an overall understanding of the systems, methods, and devices described herein, specific exemplary aspects are described. The aspects and features described herein are specifically described in the context of use in connection with an introducer sheath for percutaneous insertion of a heart pump, but all of the components and other features outlined below may be combined with each other in any suitable manner and adapted and applied to other types of introducer sheaths, other types of heart assist devices, or for the delivery of any suitable catheter, guide wire, surgical tool, or medical device.

[0015] The devices described herein include an introducer and a hub assembly for the introducer (the introducer can be used, for example, for percutaneous insertion of a heart pump). The hub can have a first hub portion and a second hub portion partially surrounding the first hub portion. The first hub portion can include a notch along which the hub can be configured to break or split. The second hub portion can include wings or tabs located on either side of the hub that can be used as leverage to apply a breaking force. The first hub portion can be formed of a soft material having low ultimate strength, while the second hub portion can be formed of a relatively rigid material having an ultimate strength greater than that of the first hub portion. In such a configuration, the soft first hub portion can allow the hub to easily break or split along the notch in the first material, while the wings of the rigid second hub portion provide improved leverage during breaking. The stiffness of the wings is selected so that they do not bend or flex excessively under pressure, but instead transfer the applied load to the notch, thereby facilitating the splitting of the introducer. Stiffer wings can also reduce the amount of elastic energy stored when force is applied to the wings during splitting of the introducer hub. This reduces the sudden release of elastic energy when the hub breaks, thereby reducing the risk of displacing or damaging the pump and / or injuring the patient or physician. Thus, by using two hub sections with different material properties, the systems, methods, and devices described herein can facilitate the splitting of the introducer sheath. By maintaining a low break force, the multi-layered hub allows for the use of introducer sheaths with larger dimensions and / or larger calibers that would otherwise be impossible to split.

[0016] The hub assembly can be manufactured in a variety of ways and can include a variety of combinations of features. For example, the second hub portion can be overmolded onto the first hub portion. The overmolding can form a bond between the first and second hub portions that prevents blood from passing through the interface between the first and second hub portions. In particular, the bond formed by overmolding can be a chemical and / or molecular bond. If the first hub portion is formed of a polymer similar to the polymer from which the second hub portion is formed, the polymer chains of the two materials can crosslink at the interface between the first and second hub portions.

[0017] Alternatively, the first and second hubs can be molded separately and then bonded together using any technique known in the art, such as using a chemical adhesive. In either case, the first hub portion can also include ridges or grooves to strengthen the bond between the first and second hub portions by increasing the surface area for polymer crosslinking and / or to provide a mechanical interlock between the first and second hub portions. This can increase the amount of force the second hub portion can transmit to the first hub portion without breaking the bond. As another example, the second hub portion can include openings over one or more notches in the first hub portion. The openings allow the first hub portion to easily break in the area of the notches, thus preserving the low break force of the hub. Thus, by maintaining a low break force, the systems, methods, and devices described herein allow the introducer hub to be larger to accommodate a larger heart pump, while still allowing it to be disassembled with the application of a reasonable amount of force.

[0018] FIG. 1 shows a plan view of an introducer hub assembly 50 including an elongate sheath 2 and a hub 10. The elongate sheath 2 is sized for insertion into a patient's blood vessel and includes a longitudinal axis 8. The hub 10 includes a first hub portion 12 having a first notch 14 and a second hub portion 16 having an opening 20 and two wings 18a and 18b. The opening 20 is provided over the first notch 14. The first notch 14 of the first hub portion 12 is aligned with or at least partially parallel to the longitudinal axis 8 of the elongate sheath 2 in some embodiments. The second hub portion 16 partially covers the first hub portion 12. In some embodiments, the second hub portion 16 is overmolded on the first hub portion 12. The second hub portion 16 includes an opening 20 over the first notch 14 that exposes the first notch 14.

[0019] The first notch 14 formed in the first hub portion 12 provides a break wall at which cracks can be generated in the hub 10 by applying force to the wings 18a and 18b. The first notch 14 can be formed of a first material having a relatively low ultimate strength breaking force. Further, the first notch 14 can be formed such that the thickness of the first material at the lower portion of the first notch 14 allows breakage of the hub 10 at the first notch 14 with a moderately low force. Additionally, the shape of the notch 14 can concentrate stress to facilitate splitting of the hub 10 along the notch 14. In some embodiments, the first hub portion 12 has a minimum thickness of 0.1 mm at the first notch 14. In some embodiments, the first hub portion 12 has a maximum thickness of 0.3 mm at the first notch 14. In some embodiments, the first hub portion 112 has a thickness of 0.075 mm, 0.08 mm, 0.09 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm or any other suitable thickness at the first notch 14.

[0020] The second hub layer 16 that partially surrounds the first hub layer 12 allows the wings 18a and 18b to be formed from a more rigid material. The rigid wings 18a and 18b allow a healthcare provider to apply a force, such as hand force, to break the hub 10 at the first notch 14. After breaking the hub, the wings 18a and 18b can be pulled apart and used to peel the introducer hub assembly 50 away from the patient and any device or guide wire extending through the blood vessel. In some embodiments, the second hub portion 16 can be overmolded onto the first hub assembly 12.

[0021] In use, the introducer hub assembly 50 facilitates the insertion of a heart pump or other medical article into a patient's blood vessel. The introducer hub assembly 50 is designed as a peel-away introducer. The elongate sheath 2 is inserted into the patient's blood vessel and the heart pump is advanced through the hub 10 and the elongate sheath 2 into the patient. During removal of the introducer hub assembly 50, the wings 18a and 18b can be grasped and a first force applied by a user, such as a healthcare provider, in the user's direction to break the hub 10 along the first notch 14. A second force can then be applied in a direction opposite the first force to break the hub 10 along a second notch (not shown). The introducer hub assembly 50, including the hub 10 and the elongate sheath 2, can then be peeled away leaving the heart pump or other medical article within the patient's blood vessel undisturbed.

[0022] Figure 2 shows a perspective view of an exemplary introducer hub assembly 100. The introducer hub assembly 100 includes an elongate sheath 102 and a hub 110. The hub 110 includes a first hub portion 112 and a second hub portion 116. The first hub portion 112 includes a first notch 114, a proximal end portion 115, and a distal end portion 117. The second hub portion 116 includes an opening 120 above the first notch 114 and two wings 118a and 118b. The elongate sheath 102 includes a longitudinal axis 108 and an inner diameter 104 sized to allow a heart pump or medical device to pass through the elongate sheath 102 and be inserted into a patient's blood vessel. The inner diameter 104 of the elongate sheath can be 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, or any other suitable diameter. In some embodiments, the inner diameter of the elongate introducer body 105 is compatible with devices having a diameter of 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), 22 French (7.33 mm), 24 French (8 mm), 26 French (8.67 mm), or any other suitable diameter. The first hub portion 112 is located closest to the outer surface 106 of the elongate sheath 102. The first hub portion 112 includes a first notch 114 oriented parallel to the longitudinal axis 108 of the elongate sheath 102. The first hub portion 112 also includes a first ridge 128a and a second ridge 128b that extend upward from the surface of the elongate sheath 106 and define the first notch 114. The second hub portion 116 partially surrounds the first hub portion 112, except for the opening 120 above the first notch 114. In some embodiments, the opening 102 is also above the first ridge 128a and the second ridge 128b of the first hub portion 112 that define the first notch 114. The second hub portion 116 includes two wings 118a and 118b that extend outwardly on each side of the hub 110.Each of the two wings 118a and 118b is configured to include a wide side 124a and 124b and a narrow side 125a and 125b. The two wings 118a and 118b can be oriented in a variety of directions. In some embodiments, the wide sides 124a and 124b of the wings 118a and 118b can be disposed perpendicular to the longitudinal axis 108 of the elongate sheath 102. In other embodiments, the narrow sides 125a and 125b of the wings 118a and 118b can be disposed perpendicular to the longitudinal axis 108 of the elongate sheath 102.

[0023] After inserting the heart pump or medical device into a patient, the introducer hub assembly 100 can be separated along the length of the first notch 114 in the hub 110 and along the length of the longitudinal cut 122 in the elongate sheath 102. The wings 118a and 118b are designed to be grasped by a healthcare professional for removal. The healthcare professional applies force to the first and second wings 118a and 118b to separate (e.g., "peel") the introducer assembly 100. This separates the hub 110 at the first notch 114 and the longitudinal cut 120, breaking the hub 110 and elongate sheath 102 in half. In some embodiments, the wings 118a and 118b are designed to be pushed in a downward motion toward the elongate sheath 102 to break the hub 110 at the first notch 114. In such embodiments, the wide sides 124a and 124b of the wings 118a and 118b may be oriented perpendicular to the longitudinal axis 108 of the elongate sheath 102. In other embodiments, the narrow sides 125a and 125b of the wings 118a and 118b may be oriented perpendicular to the longitudinal axis 108 of the elongate sheath 102 and may be designed such that forcing the two wings 118a and 118b toward each other facilitates breaking of the first notch 114. When the hub 110 breaks at the first notch 114, the wings 118a and 118b may be peeled away from each other to remove the hub 110. The elongate sheath 102 may also include a longitudinal cut 122 parallel to the longitudinal axis 108 that aligns with the first notch 114 in the hub 110. Elongate sheath 102 may be configured to split along longitudinal slit 122 to be torn away when hub 110 is broken and peeled away by pulling wings 118a and 118b away from one another. First hub portion 112 may include a second notch (e.g., 126 in FIG. 4 ) opposite first notch 114. In such a case, the second notch is also broken by pulling wings 118a and 118b away from one another.The elongate sheath 102 may further include a second longitudinal notch (not shown) through which the hub 110 may be broken and split.

[0024] The first hub portion 112 and the second hub portion 116 may be constructed of materials having different material properties. The first hub portion 112 may have different surface characteristics, durometer, ultimate or tensile strength, modulus of elasticity, or other material properties than the second hub portion 116. The second hub portion 116 may be harder, stiffer, tougher, or more rigid than the first hub portion 112. The different material properties of the first hub portion 112 from the second hub portion 116 allow the hub 110 to be efficiently broken by hand by medical personnel while increasing in size to accommodate larger pumps and medical devices. In some embodiments, the material forming the second hub portion 16 has an ultimate strength greater than the ultimate strength of the material forming the first hub portion 12. In some embodiments, the material forming the second hub portion 16 has a stiffness greater than the stiffness of the material forming the first hub portion 12. In certain embodiments, the first material forming the first hub portion 12 has a hardness of 45 Shore D. In some embodiments, the first material may have a hardness of 30 Shore D, 35 Shore D, 40 Shore D, 45 Shore D, 50 Shore D, or any other suitable hardness. In some embodiments, the second material forming the second hub portion 16 has a hardness of 60 Shore D, 65 Shore D, 68 Shore D, 70 Shore D, 72 Shore D, 75 Shore D, or any other suitable hardness.

[0025] FIG. 3 shows a perspective view of a first hub portion 112 of the introducer hub assembly 100 of FIG. 2. The first hub portion 112 is attached to the elongated sheath 102 at the proximal end of the elongated sheath 102 and includes a first notch 114 defined by a first ridge 128a, a second ridge 128b, and a ridge 130. The first notch 114 may align with a longitudinal cut 122 on the elongated sheath 102 that is parallel to the longitudinal axis 108 of the elongated sheath 102. The first hub portion 112 may define the first notch 114 at a minimum thickness 132 of the first hub portion 112 at the first notch 114. The first notch 114 may be further defined by the first ridge 128a and the second ridge 128b. The ridge 130 may be configured as a ribbed body or groove oriented in one or multiple directions on the first hub portion 112. The ridge 130 enables reliable interfacing with the overmolded layer of the first hub portion 112, promoting structural rigidity during breakage of the introducer hub assembly 100. The ridge 130 provides a mechanical connection between the first hub portion 112 and a second hub portion (e.g., 116 of FIG. 2), transmitting the torque applied to the wings (e.g., 118a and 118b of FIG. 2) to the first hub portion 112. Thus, the force applied to the wings (e.g., 118a and 118b of FIG. 2) is transmitted to the fracture wall of the first notch 114. The first hub portion 112 may form a hemostatic bond with the elongated sheath 102, particularly when both the first hub portion 112 and the elongated sheath 102 are composed of the same material.

[0026] FIG. 4 shows a perspective view of an introducer hub assembly 100 in a particular embodiment. The introducer hub assembly 100 includes an elongate sheath 102, a first hub portion 112 having a first notch 114 and a second notch 126, and a second hub portion 116 having two wings 118a and 118b. The first hub portion 112 has a proximal end portion 115 and a distal end portion 117. The first hub portion 112 is connected to the elongate sheath 102 at the distal end portion 117. The second hub portion 116 partially covers the first hub portion 112. In some embodiments, the second hub portion 112 substantially completely covers the first hub portion 116 except for an opening 120 over the first notch 114. In some embodiments, the second hub portion may cover a smaller portion of the first hub portion 112. As described above, the first and second hub portions can be formed using various techniques (e.g., overmolding the second hub portion 116 onto the first hub portion 112, or molding the first and second hub portions 112, 116 separately and then adhering them together using an adhesive).

[0027] The first notch 114 is oriented parallel to the longitudinal axis 108 of the elongate sheath 102 and is aligned with a longitudinal cut 122 of the elongate sheath 102 such that when the hub 110 breaks at the first notch 114 and the elongate sheath 102 tears along the longitudinal cut 122, the hub assembly 100 can function as a peel-away introducer. The hub 110 has a second notch 126 in the first hub portion 112 shown on the side of the hub 110 opposite the first notch 114. The second notch 126 further facilitates breaking of the hub 110 for removal of the hub assembly 100. The second notch 126 can be defined in a manner similar to the first notch 114 and can be oriented parallel to the longitudinal axis 108 of the elongate sheath 102. The longitudinal sheath 102 can include a second longitudinal cut (not shown) that aligns with the second notch 126 and is on the side opposite the longitudinal cut 122.

[0028] During removal of the introducer assembly 100, a force is applied to wings 118a and 118b to push the wide faces 124a and 124b of the wings 118a and 118b toward each other. As the force is transmitted through the material and applied toward the first notch 114, a compressive force is created at the first notch 114 in the hub and a tension is created at the second notch 126 such that the first notch 114 breaks at both. Application of a force in the opposite direction to the wings breaks the second notch 126. The first notch 114 of the first hub portion 112 and the minimum thickness 132 of the first hub portion 112 at the first notch 114 and the second notch 126 enable the hub 110 to break easily at the first notch 114 and the second notch 126. To further facilitate breaking of the hub 110 at the first notch 114 and the second notch 126, the first hub portion may include a material having a low ultimate strength. The second hub portion 116 may include a material having a higher ultimate strength than the material of the first hub portion 112. In some embodiments, the first hub portion 112 and the second hub portion 116 may be constructed of a polyether block amide (e.g., PEBAX® from Arkema Group) or a similar material. The second hub portion 116 includes wings 118a and 118b that can withstand the force required to break the hub 110 without bending, facilitating breaking of the hub. Further, the second hub portion 116 may have an increased thickness 134 where it covers the first hub portion 112 to provide rigidity to the hub 110.

[0029] FIG. 5 shows a perspective view of the first notch 114 in the introducer hub assembly 100 of FIGS. 1 and 2. The first notch 114 is formed in the first hub portion 112 with a minimum thickness 132 at the first notch 114. The first notch 114 extends the length of the first hub portion 112 from the proximal end portion 115 to the distal end portion 117. The first notch 114 is further defined by first and second ridges 128a and 128b formed in the first hub portion 112. The second hub portion 116 partially covers the first hub portion 112 and includes an opening 120 above the first notch 114. The second hub portion 116 can have a corresponding thickness 134. In some embodiments, the first hub portion 112 has a minimum thickness 132 of 0.1 mm at the first notch 114. In some embodiments, first hub portion 112 has a maximum thickness of 0.3 mm at first notch 114. In certain embodiments, first hub portion 112 has a thickness 132 at first notch 114 of 0.075 mm, 0.08 mm, 0.09 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, or any other suitable thickness.

[0030] In some embodiments, first hub portion 112 has a variable thickness 132 at first notch 114 along the length of first notch 114. In certain embodiments, first hub portion 112 has a greater thickness 132 at proximal end portion 115 than at distal end portion 117 of first hub portion 112. Distal end portion 117 of notch 114, which is closest to the connection between hub 110 and elongate sheath 102, may have the greatest stress concentration during fracture and therefore may be the intended fracture initiation point. Thus, the relatively thin fracture wall of notch 114 at distal end portion 117 reduces the force required to initiate fracture.

[0031] In some embodiments, a hemostatic valve (not shown) is included in the hub 110 at the proximal end portion 115. The proximal end portion 115 where the valve is disposed must have sufficient strength to support the hoop stress induced into the hub 110 from compression of the valve. This is particularly important when an article such as a catheter is inserted into the hub and increases the hoop stress. In some embodiments, the thickness 132 of the notch 114 at the proximal end portion 115 is greater than the thickness of the notch 114 at the distal end portion 117. The increased notch thickness at the proximal end portion 115 reinforces the hub 110 in the hoop stress increasing region. In some embodiments, the thickness of the notch 114 at the distal end portion 117 is about 0.004" to 0.006". In some embodiments, the thickness of the notch 114 at the distal end portion 117 is 0.003", 0.0035", 0.004", 0.0045", 0.005", 0.0055", 0.006", 0.0065" or any other suitable thickness. In some embodiments, the thickness of the notch 114 at the proximal end portion 115 of the first hub portion 112 is about 0.010" to 0.012". In some embodiments, the thickness of the notch 114 at the proximal end portion 115 of the first hub portion 112 is 0.0095", 0.010", 0.0105", 0.011", 0.0115", 0.012", 0.0125" or any other suitable thickness. In some embodiments, the change in thickness can occur as a smooth transition. In some embodiments, the change in thickness can occur by a series of stepwise thickness increases.

[0032] The use of a softer material to form the first hub portion 112 allows the thickness of the notch 114 to vary along its length. This is because the thickness of the notch 114 is constrained at the upper end by the maximum allowable break force and at the lower end by manufacturing tolerances. If the notch 114 is too thick, it cannot be broken. However, if it is too thin, it cannot be easily manufactured by conventional methods (e.g., injection molding). The use of a softer material for the first hub portion 112 increases the upper limit of the notch thickness, allowing for a sufficiently low break force at a larger notch thickness. This increase in the upper limit of the notch thickness provides a range over which the notch thickness can vary, thereby allowing for variation in the notch thickness along its length. Therefore, using a different material for the first hub portion 112 compared to the second hub portion 116 allows for variation in the notch thickness along its length.

[0033] FIG. 6 shows a perspective view along the longitudinal axis 108 of the elongated sheath 102 of a particular embodiment of an introducer hub assembly 100. The introducer hub assembly 100 includes an elongated sheath 102 sized to fit over a heart pump or medical device and be inserted into a patient's blood vessel. The elongated sheath 102 is surrounded by a first hub portion 112 that includes a first notch 114, which is a point where the thickness of the first hub portion 112 can be a minimum thickness 132. A second hub portion 116 surrounds the first hub portion 112 and includes an opening 120 above the first notch 114. In some embodiments, the first notch 114 can be further defined by ridges or extensions (shown as 128a and 128b in FIG. 5) on the first hub portion 112. In some embodiments, the base of the first notch 114 may be defined by the first hub portion 112, and the second hub portion 116 may further define an upper portion of the first notch 114. The second hub portion 116 also includes a first wing 118a and a second wing 118b.

[0034] FIG. 7 shows a perspective view of an alternative embodiment of an introducer hub assembly 200 having wing 218a and 218b in a horizontal orientation. The introducer hub assembly 200 includes an elongate sheath 202 having an inner diameter 204 and a longitudinal axis 208 sized to permit passage of a heart pump into a patient's blood vessel, a first hub portion 212 having a first notch 214, an opening 220 above the first notch 214, and a second hub portion 216 having first and second wings 218a and 218b.

[0035] The first wing 218a and the second wing 218b are oriented such that the broad faces 224a and 224b of the wings 218a and 218b are perpendicular to the longitudinal axis 208 of the elongate sheath 202. In this embodiment, the introducer hub assembly 200 is broken and detached from the patient using a technique different from that of the embodiment of FIG. 1. More specifically, to break the hub 210 at the first notch 214, the broad faces 224a and 224b of the wings 218a and 218b are pushed toward the elongate sheath 202. The hub 210 breaks along the first notch 214 and a second notch (not shown) on the side opposite the first notch 214. Additionally, the elongate sheath 202 tears at a longitudinal incision 222 and a second longitudinal incision (not shown) on the side opposite the longitudinal incision 222. The introducer hub assembly 200 then breaks in half and can be removed, leaving the device, catheter, or guide wire at a predetermined location within the patient's blood vessel.

[0036] FIG. 8 shows the introducer hub assembly 100 of FIGS. 2, 4, and 6 inserted into a patient's blood vessel 140, along with a percutaneous pump 142 extending partially therethrough. The percutaneous pump 142 can include various features such as a pump head 144 and a catheter body 146. The percutaneous pump 142 can be a ventricular assist device, a heart pump driven by a flexible shaft and a motor disposed outside the patient's body, a heart pump including an implantable motor, a heart pump having an expandable pump rotor, or any other suitable pump. The introducer hub assembly 100 is advanced into the blood vessel 140 through the vessel opening 150 in the direction indicated by arrow 148, and then the percutaneous pump 142 is inserted into the blood vessel 140 through the introducer hub assembly 100. The blood vessel 140 can be the femoral artery, and the vessel opening 150 can be an arteriotomy.

[0037] After the percutaneous pump 142 has been advanced through the introducer hub assembly 100, the introducer hub assembly 100 may be removed and, in some embodiments, replaced with a device suitable for long-term use. To remove the introducer hub assembly, a healthcare professional may grasp the first and second wings 118a and 118b and apply either a force toward the elongate sheath 102 or a force radial to the elongate sheath 102 (depending on the orientation of the first and second wings 118a and 118b relative to the elongate sheath 102) to urge the first wing 118a toward the second wing 118b. In the orientation of the wings 118a and 118b shown, the healthcare professional applies a radial (radial relative to the elongate sheath 102) force to the wings 118a and 118b to move them toward each other. The first and second wings 118a and 118b are formed from the rigid material of the second hub portion 116 and do not flex under the application of force. The applied force is transmitted from the wings 118a and 118b to the first and second notches 114 and 126 (not shown). A minimum thickness 132 of the first hub portion 112 at the first and second notches 114 and 126 allows the hub 110 to break at the first and second notches 114 and 126. In some embodiments, a healthcare professional applies a second radial force in the opposite direction to break the second notch 126. The longitudinal cuts 122 on the elongate sheath 102 allow the sheath to separate along the longitudinal axis 208, and the hub 110 and elongate sheath 102 can be peeled away into two pieces, leaving the percutaneous pump 142 in place in the blood vessel 140.

[0038] The foregoing is merely illustrative of the principles of the present disclosure, and the device may be practiced in other ways than those presented by way of example and not limitation. It will be understood that while the devices disclosed herein are shown for use in percutaneous insertion of a heart pump, they may also be adapted for use in devices in other applications requiring hemostasis.

[0039] After considering the present disclosure, those skilled in the art will envision variations and modifications. The disclosed features may be implemented in any combination and sub - combination (including multiple dependent and partial combinations) with one or more other features described herein. The various features, including any of their constituent parts, may be combined or integrated as other systems. Moreover, certain features may be omitted or not implemented.

[0040] Examples of changes, substitutions, and modifications are ascertainable by those skilled in the art and can be made without departing from the scope of the information disclosed herein. All references cited herein are incorporated by reference in their entirety and form part of this application.

Claims

1. An elongate sheath having a longitudinal axis sized for insertion into a patient's blood vessel; and a hub coupled to a proximal portion of the elongate sheath, the hub comprising a first hub portion having a first notch, a first ridge, and a second ridge, the first ridge and the second ridge defining an edge of the first notch, the first ridge and the second ridge extending laterally from the first hub portion, and a second hub portion partially surrounding the first hub portion wherein the second hub portion is overmolded on the first hub portion, and the second hub portion comprises two wings; and an opening provided over the first notch, wherein the first hub portion comprises a first material and the second hub portion comprises a second material, the first material being different from the second material, an introducer assembly.

2. The introducer assembly of claim 1, wherein the first material has a first ultimate strength and the second material has a second ultimate strength, the second ultimate strength being greater than the first ultimate strength.

3. The introducer assembly of claim 1, wherein the first material has a first rigidity and the second material has a second rigidity, the second rigidity being greater than the first rigidity.

4. The introducer assembly of claim 1, wherein the first notch is oriented parallel to the longitudinal axis of the elongate sheath.

5. The introducer assembly of claim 1, wherein the hub is configured to break at the first notch along the direction of the longitudinal axis of the elongate sheath.

6. The introducer assembly of claim 1, wherein the elongate sheath further comprises a longitudinal cut parallel to the longitudinal axis of the elongate sheath.

7. The introducer assembly of claim 6, wherein the elongate sheath is configured to tear along the longitudinal cut parallel to the longitudinal axis of the elongate sheath.

8. An elongate sheath having a longitudinal axis sized for insertion into a patient's blood vessel; and a hub coupled to a proximal portion of the elongate sheath, the hub comprising a first hub portion having a first notch, and a second hub portion partially surrounding the first hub portion wherein the second hub portion is overmolded on the first hub portion, and the second hub portion comprises two wings; and an opening provided over the first notch, The first hub portion includes a first material, the second hub portion includes a second material, and the first material is different from the second material. The first hub portion includes a plurality of ridges. An introducer assembly.

9. The introducer assembly according to claim 1, wherein the first hub portion and the elongate sheath form a hemostatic bond.

10. The introducer assembly according to claim 1, wherein each wing includes a wide surface and a narrow surface, and the wide surface is perpendicular to the longitudinal axis of the elongate sheath.

11. The introducer assembly according to claim 1, wherein each wing includes a wide surface and a narrow surface, and the narrow surface is perpendicular to the longitudinal axis of the elongate sheath.

12. The introducer assembly according to claim 1, wherein the first hub portion includes a second notch.

13. The introducer assembly according to claim 1, wherein the first material has a hardness of 45 Shore D.

14. The introducer assembly according to claim 1, wherein the second material has a hardness in the range of 68 to 72 Shore D.

15. The introducer assembly according to claim 1, wherein the hub has a minimum diameter of 9 Fr.

16. The introducer assembly according to claim 1, wherein the first hub portion has a thickness that varies along the length of the first notch at the first notch.

17. The introducer assembly according to claim 16, wherein the thickness of the first hub portion at the first notch is maximum at the proximal end portion of the first hub portion.

18. The introducer assembly according to claim 17, wherein the thickness of the first hub portion at the first notch is 0.01 inch to 0.012 inch at the proximal end portion of the first hub portion.

19. The introducer assembly according to claim 17, wherein the thickness of the first hub portion at the first notch is 0.004 inch to 0.006 inch at the distal end portion of the first hub portion.

20. The second hub portion is overmolded on the first hub portion such that a hemostatic bond is formed between the second hub portion and the first hub portion. The introducer assembly according to claim 1.

21. The introducer assembly according to claim 8, wherein the second hub portion is overmolded on a plurality of ridges.

Images