Cannula assembly

Abstract

To provide a cannula assembly and a method of manufacturing the cannula assembly.SOLUTION: The cannula assembly includes a cannula and a pigtail extension coupled to the cannula. The pigtail extension includes a proximal section having a first stiffness and a distal section having a second stiffness, the first stiffness greater than the second stiffness. The proximal section of the pigtail extension is positioned between the cannula and at least a portion of the distal section.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority under 35 USC § 119(e) from U.S. Provisional Application No. 61 / 992,825, filed May 13, 2014, the entire contents of which are incorporated herein by reference.

[0002] Technical Field The present disclosure relates to a cannula assembly and, more particularly, to a cannula assembly operable with a blood pump assembly, such as an intravascular heart pump system. [Background technology]

[0003] background To deliver blood from the heart to the arteries, a blood pump assembly, such as an intracardiac or intravascular blood pump, may be introduced into the heart. The blood pump assembly may be introduced percutaneously through the vascular system during a cardiac procedure. Specifically, the blood pump assembly may be inserted by a catheter procedure through the femoral or axillary / subclavian arteries, into the ascending aorta, across a valve, and into the left ventricle. Once inserted, the blood pump assembly draws blood from the left ventricle through a cannula and ejects the blood into the aorta.

[0004] The stability of the blood pump assembly within the ventricle affects the use and performance of the pump. Positioning the blood pump assembly too close to the ventricular apex can lead to suction and arrhythmia problems. Positioning the blood pump assembly too deep within the ventricle can result in the outlet being on the aortic valve or within the ventricle. If the blood pump assembly is improperly positioned, valuable time is wasted while the blood pump assembly is repositioned. The time wasted repositioning the blood pump assembly can be life-threatening, as procedures requiring such embodiments affect the viability and quality of life of the patient. Summary of the Invention

[0005] overview The systems, methods, and devices disclosed herein provide a cannula assembly for an intravascular blood pump. The cannula assembly includes a cannula coupled to a dual-rigidity pigtail extension. The dual-rigidity pigtail extension has a relatively rigid proximal section and a relatively soft distal section. The intravascular blood pump may generate a thrust force that compresses the cannula assembly against the patient's tissue. The rigid proximal section is sufficiently rigid to substantially resist buckling under such compression (e.g., a hardness of 60, 70, 80, 90, 100, or higher on the Shore D scale). In contrast, the distal section may be sufficiently soft or flexible to exhibit a tendency to buckle against the patient's tissue (e.g., a hardness of 50, 40, 30, 20, or lower on the Shore D scale). This controlled buckling allows the proximal region of the pigtail extension to substantially maintain its original length so that it can act as a mechanical spacer. This spacing can facilitate proper positioning of the intravascular blood pump relative to the patient's heart or vasculature. For example, the stiff proximal portion may prevent the blood inlet from being too close to the ventricular wall to avoid aspirating tissue. Additionally, the stiff proximal portion may ensure that the outlet of the blood pump is positioned on the opposite side of the valve (e.g., the aortic valve) relative to the inlet. This allows blood to be pumped out of the ventricle to increase cardiac output. At the same time, the relatively soft distal portion may reduce trauma to the patient's tissue. For example, the softer material of the distal portion may reduce stresses induced locally in the patient's tissue. Additionally, deformation of the distal portion of the pigtail may increase the area over which forces are transmitted to the tissue. As used herein, "endovascular" refers to a component that is positioned in whole or in part within the patient's vasculature, within the patient's heart, or both. Additionally, as used herein, dual stiffness refers to a component having at least two sections with different stiffnesses.

[0006] In some embodiments, a kit is provided that includes a cannula and two or more pigtail extensions having relatively rigid proximal sections of varying lengths (e.g., 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, or any other suitable length). Each pigtail extension in the kit has a proximal end portion configured to connect to a distal end portion of the cannula. The connection may be removable to allow a physician to change the pigtail extension originally connected to the cannula assembly. This allows a physician to select a pigtail extension that provides the appropriate spacing for positioning the intravascular blood pump for a particular patient. In some embodiments, the appropriate length of the rigid proximal section is determined using imaging (e.g., x-ray, MRI, CT scan, fluoroscopy, or ultrasound) or estimated using patient data (e.g., height, sex, age, or weight).

[0007] Various embodiments provide a blood pump assembly and methods of manufacturing and implementing the blood pump assembly. Various embodiments provide a cannula assembly including a cannula and a pigtail extension coupled to the cannula. The pigtail extension includes a proximal portion having a first stiffness and a distal portion having a second stiffness, the first stiffness being greater than the second stiffness. The proximal portion of the pigtail extension is positioned between the cannula and at least a portion of the distal portion.

[0008] In certain embodiments, the cannula assembly includes a pump coupled to the cannula. The cannula is positioned between the pump and the pigtail extension. The cannula assembly may include an impeller blade rotatably coupled to a pump motor. According to certain embodiments, the pump is coupled to the cannula by a pump housing component including a plurality of blood drainage apertures. In certain embodiments, the pump housing component includes a peripheral wall extending about an axis of rotation of the impeller blade. The peripheral wall includes a plurality of blood drainage apertures; each blood drainage aperture of the plurality of blood drainage apertures is surrounded by an aperture peripheral edge. The aperture peripheral edge extends across the peripheral wall from an inner peripheral wall surface to an outer peripheral wall surface. According to certain embodiments, the aperture peripheral edge includes a radiused edge portion radiused between the inner peripheral wall surface and the outer peripheral wall surface. The cannula component may include a blood inlet manifold. The blood inlet manifold may include a plurality of inlet openings. In certain embodiments, the proximal portion of the pigtail extension is constructed from nylon. In certain embodiments, the proximal portion of the pigtail extension is constructed from a polymer including, but not limited to, one or more of polyurethane or Pebax®. In certain embodiments, the distal portion of the pigtail extension is constructed from Pebax. In certain embodiments, the distal portion of the pigtail extension is constructed from a polymer including, but not limited to, polyurethane. The proximal portion of the pigtail extension may have a hardness or durometer value in the range of 60-100 Shore D. The distal portion of the pigtail extension may have a hardness or durometer value in the range of 20-50 Shore D. The stiffness of the proximal portion may be modified by the addition of other materials, such as glass fillers or metallic or fiber braids.

[0009] Various embodiments provide a method of manufacturing a cannula assembly. The method includes coupling a pigtail extension to a cannula. The pigtail extension includes a proximal portion having a first stiffness and a distal portion having a second stiffness less than the first stiffness. The proximal portion is positioned between the cannula and at least a portion of the distal portion. The method also includes coupling a pump to the cannula. The cannula is positioned between the pump and the pigtail extension.

[0010] In certain embodiments, an impeller blade is rotatably coupled to the pump motor. According to certain embodiments, the impeller blade is at least partially positioned within the pump housing component. According to certain embodiments, the pump is coupled to the cannula by a pump housing component including a plurality of drainage apertures. The pigtail extension may be coupled to the cannula via a blood inlet manifold. The blood inlet manifold may include a plurality of inlet openings. In certain embodiments, a proximal portion of the pigtail extension is comprised of nylon. In certain embodiments, a proximal portion of the pigtail extension is comprised of a polymer including, but not limited to, one or more of polyurethane or Pebax. In certain embodiments, a distal portion of the pigtail extension is comprised of Pebax. In certain embodiments, a distal portion of the pigtail extension is comprised of a polymer including, but not limited to, polyurethane.

[0011] [The present invention 1001] A cannula, connected to the cannula, a proximal portion having a first stiffness; and A distal portion having a second stiffness Including, the first stiffness is greater than the second stiffness; and the proximal portion being positioned between the cannula and at least a portion of the distal portion. Pigtail extension and A cannula assembly for an intravascular heart pump system comprising: [The present invention 1002] The cannula assembly of claim 10, wherein the proximal portion of the pigtail extension has a hardness within the range of about 60 to 100 Shore D. [The present invention 1003] The cannula assembly of claim 1001 or 1002, wherein the distal portion of the pigtail extension has a hardness within the range of about 20 to 50 Shore D. [The present invention 1004] A cannula assembly according to any one of claims 1001 to 1003, wherein the distal portion includes a curved portion. [The present invention 1005] Any of the cannula assemblies of claims 1001 to 1004, wherein the curved portion is curved around an axis substantially perpendicular to the central axis of the cannula. [The present invention 1006] Any of the cannula assemblies of the present inventions 1001 to 1005, wherein the curved portion is curved by more than about 180 degrees. [The present invention 1007] The cannula assembly of any of claims 1001-1006, wherein the proximal portion is dimensioned to have a buckling load greater than the thrust generated by the blood pump assembly. [The present invention 1008] A cannula assembly of any of claims 1001 to 1007, wherein the distal portion is dimensioned to have a buckling load less than the thrust generated by the blood pump assembly. [The present invention 1009] Any of the cannula assemblies of claims 1001 to 1008, wherein the proximal portion of the pigtail extension has a length of greater than about 10 mm. [The present invention 1010] The cannula assembly of any one of claims 1001 to 1009, wherein the pigtail extension is configured to be removably coupled to the cannula. [The present invention 1011] The cannula assembly of any of claims 1001 to 1010, wherein the distal portion of the pigtail extension is approximately 25% to 75% of the overall length of the pigtail extension. [The present invention 1012] The cannula assembly of any one of claims 1001 to 1011, further comprising a pump connected to the cannula, the cannula being positioned between the pump and the pigtail extension. [The present invention 1013] Any of the cannula assemblies of claims 1001 to 1012, wherein the pump is connected to the cannula by a pump housing component including a plurality of drainage apertures. [The present invention 1014] The cannula assembly of any one of claims 1001 to 1013, wherein the cannula includes a blood inlet manifold. [The present invention 1015] Any of the cannula assemblies of claims 1001 to 1014, wherein the proximal portion of the pigtail extension is made of nylon. [The present invention 1016] The cannula assembly of any one of claims 1001 to 1015, wherein the proximal portion of the pigtail extension is constructed from a polymer including one or more of polyurethane and pebax. [The present invention 1017] Any of the cannula assemblies of claims 1001 to 1016, wherein the distal portion of the pigtail extension is constructed from Pebax. [The present invention 1018] Any of the cannula assemblies of claims 1001 to 1017, wherein the distal portion of the pigtail extension is made of polyurethane. [The present invention 1019] coupling a pigtail extension to a cannula, the pigtail extension including a proximal portion having a first stiffness and a distal portion having a second stiffness, the proximal portion being positioned between the cannula and at least a portion of the distal portion; and connecting a pump to the cannula, the cannula being positioned between the pump and the pigtail extension; 1. A method for manufacturing a cannula assembly for an intravascular heart pump system, comprising: [The present invention 1020] 1020. The method of claim 1019, wherein the proximal portion of the pigtail extension has a hardness in the range of 60 to 100 Shore D. [The present invention 1021] The method of any one of claims 1019 to 1020, wherein said distal portion of said pigtail extension has a hardness within the range of 20 to 50 Shore D. [The present invention 1022] Any of the methods of claims 1019 to 1021, wherein the pump is connected to the cannula by a pump housing component including a plurality of drainage apertures. [The present invention 1023] The method of any one of claims 1019 to 1022, wherein the pigtail extension is connected to the cannula via a blood inlet manifold. [The present invention 1024] The method of any one of claims 1019 to 1023, wherein the pigtail extension is removably coupled to the cannula. [The present invention 1025] A cannula, a first pigtail extension including a first proximal portion having a first stiffness and a first length and a first distal portion having a second stiffness, the first stiffness being greater than the second stiffness; a second pigtail extension including a second proximal portion having a third stiffness and a second length and a second distal portion having a fourth stiffness, the third stiffness being greater than the fourth stiffness; Equipped with the second length is greater than the first length, and the first pigtail extension and the second pigtail extension are each configured to removably couple to the cannula; Cannula assembly kit for intravascular heart pump system. Variations and modifications will occur to those skilled in the art after reviewing this disclosure. The disclosed features may be implemented in any combination and subcombination (including multiple subordinate combinations and subcombinations) with one or more other features described herein. The various features described or illustrated above, including any components thereof, may be combined or integrated into other systems. Furthermore, certain features may be omitted or not implemented. It should be understood that all combinations of the above concepts and additional concepts described in more detail below are contemplated as part of the inventive subject matter disclosed herein (unless such concepts are mutually inconsistent). In particular, all combinations of claimed subject matter at the end of this disclosure are contemplated as part of the inventive subject matter disclosed herein. [Brief description of the drawings]

[0012] Those skilled in the art will appreciate that the accompanying drawings are primarily for illustrative purposes and are not intended to limit the scope of the subject matter described herein. The drawings are not necessarily to scale, and in some cases, various aspects of the subject matter disclosed herein may be shown exaggerated or enlarged in the drawings to aid in understanding different features. In the drawings, like reference symbols generally refer to similar features (e.g., functionally similar and / or structurally similar elements, etc.). [Figure 1] 1 illustrates a cannula assembly according to an exemplary embodiment. [Diagram 2] 1 illustrates a side cross-sectional view of a pigtail extension in accordance with an exemplary embodiment. [Diagram 3] 3 illustrates an end view of the pigtail extension of FIG. 2. [Figure 4] 1 illustrates a method of manufacturing a cannula assembly, according to certain embodiments.

[0013] The features and advantages of the inventive concepts disclosed herein will become more apparent from the following description read in conjunction with these drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Detailed Description Below is a more detailed description of various concepts relating to the systems and methods of the present invention for providing a cannula assembly, and embodiments of the systems and methods of the present invention. It should be understood that the disclosed concepts are not limited to any particular manner of embodiment, and thus the various concepts outlined above and described in more detail below may be implemented in any of numerous ways. Examples of specific embodiments and applications are provided primarily for purposes of illustration.

[0015] The systems, methods, and devices disclosed herein provide a cannula assembly for an intravascular blood pump. The cannula assembly includes a cannula coupled to a dual-rigidity pigtail extension. The dual-rigidity pigtail extension has a relatively rigid proximal section and a relatively soft distal section. The intravascular blood pump may generate a thrust force that compresses the cannula assembly against the patient's tissue. The rigid proximal section is sufficiently rigid to substantially resist buckling under such compression (e.g., a hardness of 60, 70, 80, 90, 100, or higher on the Shore D scale). In contrast, the distal section may be sufficiently soft or flexible to exhibit a tendency to buckle against the patient's tissue (e.g., a hardness of 50, 40, 30, 20, or lower on the Shore D scale). This controlled buckling allows the proximal region of the pigtail extension to substantially maintain its original length so that it can act as a mechanical spacer. This spacing can facilitate proper positioning of the intravascular blood pump relative to the patient's heart or vasculature. For example, the stiff proximal portion may prevent the blood inlet from being too close to the ventricular wall to avoid aspirating tissue. Additionally, the stiff proximal portion may ensure that the outlet of the blood pump is positioned on the opposite side of the valve (e.g., the aortic valve) relative to the inlet. This allows blood to be pumped out of the ventricle to increase cardiac output. At the same time, the relatively soft distal portion may reduce trauma to the patient's tissue. For example, the softer material of the distal portion may reduce stresses induced locally in the patient's tissue. Additionally, deformation of the distal portion of the pigtail may increase the area over which forces are distributed to the tissue. Intravascular as used herein refers to a component that is positioned in whole or in part within the patient's vasculature, within the patient's heart, or both. Additionally, dual stiffness as used herein refers to a component having at least two sections with different stiffnesses.

[0016] FIG. 1 illustrates a blood pump assembly according to an exemplary embodiment. The blood pump assembly 100 includes a blood pump 101, a housing component 102, an impeller blade 103 rotatably coupled to the blood pump 101, a cannula 104, a blood inlet manifold 105, a pigtail extension 106, and a catheter 107. The blood pump 101 is coupled to the cannula 104 by the housing component 102 at a distal end of the cannula 104. The blood pump 101 is also coupled to the catheter 107. In some embodiments, the blood pump 101 includes a motor. In such cases, the catheter 107 may contain electrical leads that communicatively couple the pump 101 to one or more electronic controllers or other sensors. In certain embodiments, the pump 101 is driven by a flexible shaft. In such cases, a drive portion of the motor may be located outside the patient's body, and the catheter 107 may contain the flexible shaft. The catheter 107 may also house other components, such as, for example, a purge fluid conduit or other conduits configured to receive a guidewire or other components associated with the procedure. The housing component 102 includes one or more apertures or openings 109 configured to expel or drain blood drawn into the cannula 104 out of the blood pump assembly 100. In certain embodiments, the housing component 102 encloses the blood pump 101.

[0017] In certain embodiments, the blood pump 101 comprises a micro axial pump having a pumping capacity ranging, including but not limited to, 5 L / min to 2.5 L / min. In certain embodiments, the blood pump 101 comprises a micro axial pump having a diameter ranging, including but not limited to, 21 Fr to 10 Fr.

[0018] The cannula 104 may include an elongated flexible hose section and may include a shape memory coil, such as a Nitinol coil. In certain embodiments, the cannula 104 is at least partially constructed from a polyurethane material. In certain embodiments, the cannula 104 has a diameter including, but not limited to, a range of 12 Fr to 9 Fr. In certain embodiments, the cannula 104 includes a 45° bend. The cannula 104 includes a blood inlet manifold 105 coupled to the cannula 104 at a proximal end thereof for receiving blood flow into the blood pump assembly 100. The blood inlet manifold 105 includes one or more blood inlet openings positioned within the inlet manifold 105. The blood inlet manifold 105 couples a pigtail extension 106 to the cannula 104.

[0019] The pigtail extension 106 helps stabilize and position the blood pump assembly 100 in the correct position within the left ventricle. In certain embodiments, the pigtail extension has an outer diameter ranging from, but not limited to, 4Fr to 8Fr. In operation, the blood pump assembly 100 is percutaneously inserted through the femoral or axillary / subclavian arteries and into the left ventricle. When properly positioned, the blood pump assembly 100 delivers blood from an inlet area of ​​the blood inlet manifold 105 inside the left ventricle, through the cannula 104, and to an outlet opening of the housing component 102 positioned within the ascending aorta.

[0020] According to certain embodiments, the pigtail extension 106 can be configured from a straight configuration to a partially curved configuration. FIG. 1 shows the pigtail extension in a curved configuration. The curve is about an axis that is substantially perpendicular to the central axis of the cannula. In some embodiments, the curve is greater than 180 degrees (e.g., 200, 220, 240, 260, 270, 300, 320 degrees, or any suitable angle). In some embodiments, the curve is less than 180 degrees (e.g., 90, 100, 120, 140, 160 degrees, or any suitable angle). Thus, the pigtail extension 106 may be constructed, at least in part, from a flexible material. The pigtail extension 106 has a dual stiffness. Specifically, the pigtail extension 106 includes a distal portion 107 and a proximal portion 108, with the proximal portion 108 constructed from a material having a higher stiffness than the distal portion 107. The proximal portion 108 may be constructed of a different material and may have a different structure than the blood inlet manifold 105 and the cannula 104. In certain embodiments, the proximal portion 108 is sufficiently rigid to substantially prevent buckling of the proximal portion 108, thereby spacing the blood inlet opening of the blood inlet manifold 105 away from the ventricular apex. The rigidity of the proximal portion 108 also reduces the likelihood that the blood outlet opening or drainage aperture 109 of the housing component 102 will migrate into the aortic valve or into the ventricle of the heart. The distal portion 107 of the pigtail extension 106 is flexible relative to the proximal portion 108 to provide an atraumatic tip for contacting the ventricular wall. This flexibility also allows for the insertion of a guidewire through the inner conduit 210 of the pigtail extension 106. In certain embodiments, the proximal and distal portions 108, 107 of the pigtail extension are constructed from different materials having different stiffnesses. In certain embodiments, the proximal and distal portions 108, 107 of the pigtail extension are constructed from the same material having different stiffnesses.

[0021] In some embodiments, the length of the proximal portion 108 of the pigtail extension is selected based on the size of the left ventricle of a particular patient. For example, a physician may be provided with a kit that includes two or more pigtail extensions with rigid proximal portions of various lengths. Each pigtail extension in the kit may have a proximal end portion configured to couple to a cannula (such as at the blood inlet manifold 105). In particular, the proximal end portion of the pigtail extension may be configured to removably couple to the cannula. For example, the proximal end portion of the pigtail extension may include a snap connection, an interference fit, a threaded connector, or any other suitable reversible or removable connector. This allows the physician to change the pigtail extension originally connected to the cannula while still being sufficiently secure to prevent the pigtail extension connection from becoming dislodged within the patient's vasculature. In certain embodiments, this allows the kit to initially include a cannula with a "standard" sized pigtail initially connected to the catheter 104, which may be exchanged for a larger or smaller pigtail as needed. The "standard" pigtail extension may be sized to fit a majority of patients (e.g., 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 95%), while a larger or smaller size may fit the remaining patients. The physician may select a pigtail extension with an appropriate proximal length based on medical images. For example, the physician may determine the ventricular size using MRI, CT, x-ray, ultrasound, fluoroscopy, or any other suitable imaging method. In certain embodiments, this size is determined preoperatively. In some embodiments, the physician estimates the ventricular size using patient data (e.g., age, height, weight, sex).

[0022] FIG. 2 illustrates a side cross-sectional view of pigtail extension 206 according to an exemplary embodiment. FIG. 3 illustrates an end view of pigtail extension 206 of FIG. 2. Pigtail extension 206 includes proximal section 208, distal section 207 including curved tip 212, and conduit 210 for use with a guidewire. Pigtail extension 206 has a dual stiffness since proximal section 208 has a greater stiffness than distal section 207. In an exemplary embodiment, distal section 207 and proximal section 208 are constructed from one or more layers of material provided to impart different stiffness to the two sections. In certain embodiments, proximal and distal sections have corresponding diameters. For example, proximal section 208 may be constructed from a single layer of a first material having a first thickness and a first stiffness, and distal section 207 may be constructed from two layers of material. In such a case, the two layers may include a first layer of a first material with a second thickness less than the first thickness, and a second layer of a second material with a third thickness (the sum of the second and third thicknesses corresponds to the first thickness) and a second stiffness. Thus, the distal portion 207 may have an overall lower stiffness than the proximal portion 208, and may be specifically configured to curl or buckle. The stiff proximal portion 208 is sufficiently stiff to substantially resist buckling under such compression (e.g., 60, 70, 80, 90, 100, or higher on the Shore D scale). The distal portion 207 is sufficiently soft or flexible to exhibit a tendency to buckle against the patient's tissue (e.g., 50, 40, 30, 20, or lower on the Shore D scale). In some embodiments, the distal portion may be made stiffer by incorporating additional materials, such as metal, fiber, braided metal or fiber, glass, or any other suitable material.

[0023] In some embodiments, the proximal portion may be made stiffer than the distal portion by incorporating additional material into the proximal portion, such as metal, fiber, braided metal or fiber, glass, or any other suitable material. The additional material may be added by injection molding, coextrusion, gluing, heat reflow processing, or any other suitable process. In some embodiments, the additional material forms a matrix or other suitable structure within the proximal portion. To reinforce the transition from the proximal portion to the distal portion, the additional material may extend from the proximal portion partially into the distal portion. In certain embodiments, the additional material may be placed between the first and second layers of material of the stiff proximal portion. Incorporating additional material into the proximal portion allows for the stiffness difference to be achieved using a single base material for the proximal and distal portions. Using a single base material for the proximal and distal portions may help achieve a melt in the transition area between the proximal and distal portions. This may facilitate joining the proximal portion to the distal portion during manufacturing.

[0024] An intravascular or intracardiac blood pump may generate a thrust force that compresses the cannula assembly against the patient's tissue, and the stiffness of the proximal portion allows the proximal region to maintain its original length and act as a mechanical spacer to maintain proper positioning of the intravascular blood pump. Thus, the stiff proximal portion 208 may prevent the blood inlet from being too close to the ventricular wall to avoid aspirating tissue. The stiff distal portion 208 may ensure that the outlet of the blood pump (e.g., blood pump 101) is positioned on the opposite side of the valve (e.g., aortic valve) from the inlet. This allows blood to be pumped out of the ventricle to increase cardiac output. At the same time, the relatively soft distal region may reduce trauma to the patient's tissue. For example, a softer material at the distal portion may reduce stresses induced locally in the patient's tissue. Additionally, deformation of the distal portion of the pigtail may increase the area over which forces are distributed to the tissue.

[0025] In certain embodiments, the pigtail extension 206 includes a curved tip 212. In some embodiments, the pigtail extension 206 is configurable from a straight configuration to a partially curved configuration. The curve of the curved tip is about an axis that is substantially perpendicular to the central axis of the cannula. In some embodiments, the curve is greater than 180 degrees (e.g., 200, 220, 240, 260, 270, 300, 320 degrees, or any suitable angle). In certain embodiments, the curve is less than 180 degrees (e.g., 90, 100, 120, 140, 160 degrees, or any suitable angle).

[0026] The pigtail extension 206 also includes a conduit 210 extending through the proximal and distal portions. The conduit 210 is sized to receive a guidewire through the pigtail extension 206. In certain embodiments, the proximal portion 208 of the pigtail extension 206 is constructed from nylon. In some embodiments, the proximal portion 208 of the pigtail extension 206 is constructed from a polymer including, but not limited to, one or more of polyurethane or Pebax. In certain embodiments, the distal portion 207 of the pigtail extension 206 is constructed from Pebax. In certain embodiments, the distal portion 207 of the pigtail extension 208 is constructed from a polymer including, but not limited to, polyurethane. The proximal portion 208 of the pigtail extension 206 may have a hardness or durometer value in the range of 60-100 Shore D. The distal portion 207 of the pigtail extension 208 may have a hardness or durometer value in the range of 20-50 Shore D. According to certain embodiments, the distal portion 207 of the pigtail extension 206 comprises 25-75% of the overall length of the pigtail extension 206.

[0027] FIG. 4 illustrates a method 400 for manufacturing a cannula assembly according to certain embodiments. Method 400 may be performed to manufacture cannula assembly 100 in any of the embodiments described above. In step 402, a dual-rigidity pigtail extension, such as pigtail extension 106 or 206 of FIGS. 1 and 2, is coupled to a cannula. The pigtail extension includes a relatively rigid proximal section and a relatively flexible distal section. The pigtail extension may be removably coupled to the cannula, or the pigtail extension may be permanently coupled to the cannula. In step 404, a pump is coupled to the cannula such that the cannula is positioned between the pump and the pigtail extension.

[0028] As used herein, the terms "approximately", "about", "substantially" and similar terms are intended to have a broad meaning consistent with common usage accepted by those skilled in the art to which the content of this disclosure belongs. As should be understood by those skilled in the art who review this disclosure, these terms are intended to enable the description of specific features described, but not to limit those features to the precise numerical ranges provided. Thus, these terms should be interpreted as indicating that non-substantial or non-important modifications or changes to the described content are considered to be within the scope of this disclosure.

[0029] For purposes of this disclosure, the term "coupled" means connecting two members to one another directly or indirectly. Such connection may be static or movable in nature. Such connection may be achieved by the two members, or the two members and any additional intermediate members integrally formed with one another as a single unit, or by the two members, or the two members and any additional intermediate members attached to one another. Such connection may be of a permanent nature or of a removable or releasable nature.

[0030] It should be noted that according to other exemplary embodiments, the orientation of various elements may differ, and such variations are intended to be encompassed by the present disclosure. It is recognized that features of the disclosed embodiments may be incorporated in other disclosed embodiments.

[0031] It is important to note that the construction and arrangement of the device or its components as shown in the various exemplary embodiments are illustrative only. While only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that numerous modifications (e.g., variations in size, dimensions, configuration, shape, and proportions of various elements, parameter values, mounting arrangements, use of materials, colors, orientations, etc.) are possible without significantly departing from the novel teachings and advantages of the disclosure. For example, elements shown as integrally formed may be constructed as multiple pieces or elements, the positions of elements may be reversed or otherwise changed, and the nature or number of separate elements or positions may be modified or changed. The order of any process or method steps may be changed or reordered according to alternative embodiments. Other substitutions, modifications, changes, and omissions may be made to the design, operating conditions, and arrangements of the various exemplary embodiments without departing from the scope of the disclosure.

[0032] While various embodiments of the invention have been described and illustrated herein, it is contemplated that one of ordinary skill in the art can readily envision a variety of other mechanisms and / or structures for performing the functions described herein and / or obtaining the results and / or one or more of the advantages described herein, and each such variation and / or modification is contemplated to fall within the scope of the inventive embodiments described herein. More generally, one of ordinary skill in the art will readily appreciate that any parameters, dimensions, materials, and configurations described herein are intended to be exemplary unless otherwise specified, and that the actual parameters, dimensions, materials, and / or configurations will vary depending on the specific application for which the teachings of the invention are used. Those of ordinary skill in the art will recognize, or be able to ascertain using no more than routine experimentation, numerous equivalents to the specific embodiments of the invention described herein. It is therefore to be understood that the above-described embodiments have been presented by way of example only, and that within the scope of the appended claims and their equivalents, embodiments of the invention may be practiced other than as specifically described and claimed. The inventive embodiments of the present disclosure relate to each individual feature, system, article, material, kit, and / or method described herein. In addition, any combination of two or more of such features, systems, articles, materials, kits, and / or methods is within the inventive scope of the present disclosure, provided that such features, systems, articles, materials, kits, and / or methods are not mutually inconsistent.

[0033] Additionally, the techniques described herein may be implemented as a method, at least one example of which is provided above. The acts performed as part of a method may be ordered in any suitable manner, unless otherwise indicated. Thus, embodiments may be constructed such that the acts are performed in an order different from that illustrated, which may include performing some acts simultaneously even though they are shown in the exemplary embodiments as sequential acts.

[0034] The indefinite articles "a" and "an" as used herein and in the claims should be understood to mean "at least one" unless expressly indicated otherwise. When used herein and in the claims, "or" should be understood to have the same meaning as "and and / or or" as defined above. For example, when separating items in a list, "or" or "and and / or or" should be interpreted as being inclusive, i.e., including at least one, but also including two or more of a plurality of elements or a list of elements, and optionally including additional items that are not listed. Only terms expressly stated to the contrary, such as "only one of" or "exactly one of," are meant to include exactly one element of a plurality of elements or a list of elements. As a whole, the term "or" as used in this specification should be construed as indicating exclusivity (i.e., "one or the other, but not both") only when preceded by exclusive terms, such as "either," "one of," "only one of," or "exactly one of."

[0035] As used herein and in the claims, the phrase "at least one" in reference to one or more elements should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each element specifically listed in the list of elements, and not excluding any combination of elements in the list of elements. This definition also allows for the optional presence of elements different from those specifically identified in the list of elements to which the phrase "at least one" refers, whether related to those elements specifically identified. Thus, as a non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B" or, equivalently, "at least one of A and / or B") can refer in one embodiment to at least one A, optionally including more than one, with no B (and optionally including elements other than B); in another embodiment to at least one B, optionally including more than one, with no A (and optionally including elements other than A); in yet another embodiment to at least one A, optionally including more than one, and at least one B (and optionally including other elements), optionally including more than one, etc.

[0036] In the claims as well as in the above specification, all transitional phrases such as "comprising," "including," "carrying," "having," "containing," "accompanying," "holding," "comprising," and the like, should be understood to be open-ended, i.e., to mean including but not limited to.

[0037] The claims should not be read as limited to the described order or elements unless stated to that effect. It should be understood that various changes in form and detail can be made by those skilled in the art without departing from the spirit and scope of the appended claims. All embodiments that come within the spirit and scope of the following claims and equivalents thereto are claimed.

Claims

1. A blood pump, an impeller rotatably coupled to the blood pump; a cannula including a proximal end and a distal end, the proximal end of the cannula being coupled to the blood pump; a catheter connected to the blood pump, the blood pump being positioned between the catheter and the cannula; a proximal portion having a first stiffness; and A distal portion having a second stiffness Including, the first stiffness is greater than the second stiffness; and the proximal portion is coupled to the distal portion of the cannula. Pigtail extension and An intravascular heart pump system comprising:

2. The intravascular heart pump system of claim 1, wherein the proximal portion of the pigtail extension has a hardness in the range of 60 to 100 Shore D.

3. An intravascular heart pump system as described in claim 1 or 2, wherein the distal portion of the pigtail extension has a hardness within the range of 20 to 50 Shore D.

4. An intravascular heart pump system as described in any one of claims 1 to 3, wherein the distal portion includes a curved portion.

5. An intravascular heart pump system as described in any one of claims 1 to 4, wherein the curved portion is curved around an axis substantially perpendicular to the central axis of the cannula.

6. An intravascular heart pump system as described in any one of claims 1 to 5, wherein the curved portion is curved by more than 180 degrees.

7. An intravascular heart pump system as described in any one of claims 1 to 6, wherein the proximal portion of the pigtail extension has a length of greater than 10 mm.

8. An intravascular heart pump system as described in any one of claims 1 to 7, wherein the pigtail extension is configured to be removably connected to the cannula.

9. An intravascular heart pump system as described in any one of claims 1 to 8, wherein the distal portion of the pigtail extension is 25% to 75% of the total length of the pigtail extension.

10. An intravascular heart pump system as described in claim 1, wherein the proximal portion is dimensioned to have a buckling load greater than the thrust generated by the intravascular heart pump system.

11. An intravascular heart pump system as described in claim 1, wherein the distal portion is dimensioned to have a buckling load that is less than the thrust generated by the intravascular heart pump system.

12. An intravascular heart pump system as described in any one of claims 1 to 11, further comprising a pump housing component including a plurality of blood drainage apertures, the pump being connected to the proximal end of the cannula by the pump housing component, and the impeller being positioned at least partially within the pump housing component.

13. The intravascular heart pump system of claim 12, wherein the cannula includes a blood inlet manifold at the distal end of the cannula, and the proximal portion of the pigtail extension is connected to the blood inlet manifold.

14. An intravascular heart pump system as described in any one of claims 1 to 13, wherein the blood pump includes a motor and the catheter carries conductors connecting the blood pump to one or more electrical controllers or one or more sensors.

15. An intravascular heart pump system as described in any one of claims 1 to 13, further comprising a flexible shaft that drives the blood pump, the catheter housing the flexible shaft.

16. An intravascular heart pump system as described in any one of claims 1 to 15, wherein the cannula includes an elongated flexible hose portion and a shape memory coil.

17. An intravascular heart pump system as described in any one of claims 1 to 16, wherein the proximal portion of the pigtail extension is constructed from nylon.

18. An intravascular heart pump system as described in any one of claims 1 to 17, wherein the proximal portion of the pigtail extension is constructed from a polymer including one or more of polyurethane and Pebax (registered trademark).

19. An intravascular heart pump system as described in any one of claims 1 to 18, wherein the distal portion of the pigtail extension is constructed from Pebax (registered trademark).

20. An intravascular heart pump system as described in any one of claims 1 to 19, wherein the distal portion of the pigtail extension is constructed from polyurethane.

21. The intravascular heart pump system of claim 1, wherein the proximal portion of the pigtail extension comprises a single layer of a first material having a first thickness, and the distal portion of the pigtail extension comprises a first layer of the first material having a second thickness and a second layer of a second material having a third thickness, the sum of the second thickness and the third thickness corresponding to the first thickness.

22. The intravascular heart pump system of claim 21, wherein the first material and the second material are different materials.

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