Graft fixation devices, systems, and methods

Abstract

To provide devices and methods useful for securing a graft material to a body structure.SOLUTION: Vascular graft 107 includes at least one conduit having a first conduit region and a second conduit region, at least one perturbation formed in the conduit in the second conduit region and configured to cause a vortex in the second conduit region.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 61 / 681,988, entitled "GRAFT ANCHOR DEVICES, SYSTEMS, AND METHODS," filed August 10, 2012, which is incorporated herein by reference in its entirety.

[0002] Technical Field FIELD OF THE DISCLOSURE The present disclosure relates generally to medical devices, and more particularly to devices and methods useful for securing graft materials to body structures. [Background technology]

[0003] background Implant materials, such as grafts, that promote tissue ingrowth can be used in medical technology, particularly in applications involving the replacement, strengthening, and / or repair of blood vessels. These materials may or may not be naturally derived, and when implanted in a patient, cells and other bodily substances from the patient can infiltrate the material, resulting in, for example, new tissue growth on, around, and / or within the implanted material. While tissue ingrowth can enhance the biocompatibility of such implants, excessive tissue growth can result in undesirable complications.

[0004] Such grafts and graft fixation devices can be used in implantable ventricular artificial hearts (VADs) to create inflow and outflow conduits connecting the circulatory system. One of the major challenges for such devices when implanted for the long term is controlling cell ingrowth. Summary of the Invention

[0005] overview In certain aspects, the present disclosure provides unique methods and systems for securing graft material to a wall of a body structure. Some methods and systems include securing a first graft component to a wall of a body structure, where new tissue growth is promoted on, around, and / or within the first graft. The first graft component is intended to provide a cuff structure that facilitates the securement of a second graft component. The second graft component and the first graft component may have the same or substantially similar materials, biological properties, mechanical properties, and / or dimensions. Alternatively, the second graft component may have different materials, biological properties, mechanical properties, and / or dimensions than the first graft component. The graft may be formed from two or more similar or different components.

[0006] In another aspect, the present disclosure provides a graft formed from components having different properties that can be bonded together to impart different properties to different portions of the graft.

[0007] In another aspect, the present disclosure provides techniques for restricting cellular in-growth to the proximal components of the graft, but not to other components; thus, cell growth is restricted to one or more components, but not all components.

[0008] In another aspect, the present disclosure provides a technique used to have grafts of different diameters joined in such a way that vortices can be formed in sections of the graft to enhance the "washout" effect in certain sections of the graft and thus limit any cell proliferation or attachment in such sections of the graft.

[0009] In another aspect, the present disclosure provides a technique used to have a single graft with internal deformations that intentionally create vortices in the flow to disrupt any cell accumulation in such areas.

[0010] In another aspect, the present disclosure provides a technique used to have a single graft with different internal structures or properties in different regions to enhance certain responses or behaviors in certain regions while other regions inhibit certain responses and behaviors.

[0011] In one embodiment, a vascular graft is provided. The vascular graft includes at least one conduit having a first conduit portion and a second conduit portion. The vascular graft further includes at least one perturbation formed in the conduit in the second conduit portion and configured to induce a vortex in the second conduit portion.

[0012] The first conduit portion may comprise a first material and the second conduit portion may comprise a second material different from the first material. The first material may comprise silicone rubber. The second material may comprise porous ePTFE. The second material may comprise woven Dacron®.

[0013] At least one perturbation may reduce the inner diameter of the conduit section. At least one perturbation may be tapered.

[0014] The first conduit portion and the second conduit portion may have substantially the same diameter.

[0015] The vascular graft may include a blood flow assist system coupled to at least one of the conduits.

[0016] Another embodiment provides a vascular graft including at least one conduit having a first conduit section and a second conduit section. The second conduit section includes a bulbous portion relative to the first conduit section. The graft further includes at least one first support strut positioned within the first conduit section. The at least one first support strut is formed in a spiral shape. The graft further includes at least one second support strut positioned within the second conduit section.

[0017] At least one second support strut may be sutured to the outer wall of the bulbous portion of the second conduit portion.

[0018] The at least one second support strut may be constructed from stainless steel wire.

[0019] The system may include a blood flow assist system coupled to at least one of the conduits.

[0020] [The present invention 1001] at least one conduit having a first conduit portion and a second conduit portion; at least one perturbation formed in the conduit at the second conduit section and configured to induce a vortex in the second conduit section; vascular grafts, including [The present invention 1002] The vascular graft of the present invention 1001, wherein the first conduit portion comprises a first material and the second conduit portion comprises a second material different from the first material. [The present invention 1003] The vascular graft of the present invention 1002, wherein the first material comprises silicone rubber. [The present invention 1004] The vascular graft of the present invention 1002, wherein the second material comprises porous ePTFE. [The present invention 1005] The vascular graft of the present invention 1002, wherein the second material comprises woven Dacron. [The present invention 1006] 1001. The vascular graft of claim 10, wherein said at least one perturbation reduces the diameter of the conduit portion. [The present invention 1007] The vascular graft of the present invention 1001, wherein said at least one perturbation is tapered. [The present invention 1008] The vascular graft of the present invention 1001, wherein the first conduit portion and the second conduit portion have substantially the same diameter. [The present invention 1009] 1001. The vascular graft of claim 10, further comprising a blood flow assist system coupled to said at least one conduit. [The present invention 1010] forming at least one conduit; At least one of forming and attaching a perturbation in the at least one conduit configured to induce vortices in fluid flowing from the first conduit section to the second conduit section to separate the first conduit section from the second conduit section. A method for forming a vascular graft, comprising: [The present invention 1011] 10. The method of claim 10, further comprising the step of connecting a blood flow assist system to said at least one conduit. [The present invention 1012] at least one conduit having a first conduit section and a second conduit section, the second conduit section including a bulbous portion relative to the first conduit section; At least one first support strut positioned within the first conduit portion and formed in a spiral shape. at least one second support strut positioned within the second conduit section; vascular grafts, including [The present invention 1013] 1013. The system of claim 1012, wherein said at least one second support strut is sutured to an outer wall of said bulbous portion of the second conduit portion. [The present invention 1014] The system of claim 1012, wherein said at least one second support strut is constructed from stainless steel wire. [The present invention 1015] The system of claim 1012, further comprising a blood flow assist system coupled to said at least one conduit. It should be recognized that all combinations of the foregoing concepts and additional concepts discussed in more detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter listed at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein. It should also be recognized that terms explicitly used herein, which may also appear in any disclosures incorporated by reference, should be given the meaning most consistent with the specific concepts disclosed herein. [Brief explanation of the drawings]

[0021] Those skilled in the art will understand that the accompanying drawings are primarily for illustrative purposes and are not intended to limit the scope of the inventive subject matter described herein. The drawings are not necessarily to scale; in some cases, various aspects of the inventive subject matter disclosed herein may be shown exaggerated or enlarged in the drawings to facilitate an understanding of different features. In the drawings, like reference characters typically refer to like features (e.g., functionally similar elements and / or structurally similar elements).

[0022] [Figure 1] 1 shows a graft made of two components having different diameters and different properties, according to an exemplary embodiment of the present invention. [Figure 2] 1 shows a single graft having internal structures to form a vortex that is believed to limit any cell accumulation in that area, according to an exemplary embodiment of the present invention. [Figure 3] 1 shows a single graft having two regions containing distinct internal structural features that respond and behave differently in the presence of blood flow, according to an exemplary embodiment of the present invention. [Figure 4] 1 illustrates a conduit having a support structure according to an exemplary embodiment of the present invention. [Figure 5] 1 illustrates a counterpulsation system according to an exemplary embodiment of the present invention. [Figure 6] 1 illustrates the surgical implantation of a graft component, according to an exemplary embodiment of the present invention. [Figure 7] 1 illustrates the surgical implantation of a graft component, according to an exemplary embodiment of the present invention. [Figure 8] 10 illustrates a method of connecting two flanges of a graft component according to an exemplary embodiment of the present invention. [Figure 9] 10 illustrates a method of connecting two flanges of a graft component according to an exemplary embodiment of the present invention. [Figure 10] 10A and 10B show vertical cross-sectional views of the connected graft components of FIGS. 8 and 9. FIG. [Figure 11] Shown is a bubble or bulged area constructed by "splitting" the bubble in the middle of the hemisphere. [Figure 12] 1 shows a cross-sectional view of a graft component according to an exemplary embodiment of the present invention. [Figure 13] 1 shows the placement of a "bubble" or bulging area of ​​graft material positioned away from the anastomosis. [Figure 14] 14A and 14B illustrate a pump connected to a graft component, according to an exemplary embodiment of the present invention.

[0023] The features and advantages of the inventive concepts disclosed herein will become more apparent from the detailed description set forth below when taken in conjunction with the accompanying drawings. DETAILED DESCRIPTION OF THE INVENTION

[0024] Detailed Description Various concepts related to, and exemplary embodiments of, the present devices, systems, and methods for providing graft fixation are described in more detail below.

[0025] While the present disclosure may be embodied in many different forms, for the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiments illustrated in the accompanying drawings, and specific terminology will be used to describe the same. It will be understood, however, that no limitation of the scope of the disclosure is thereby intended. Any alterations and further modifications in the described embodiments, and any further applications of the principles of the disclosure as described herein, that would normally occur to one skilled in the art to which this disclosure pertains, are contemplated.

[0026] The present disclosure, in certain aspects, provides a vascular graft 102 including a first component 101 with a sewing cuff 105 and a second component 102 with another sewing cuff 103. The first component 101 can be attached to a blood vessel 104 using commonly practiced suturing techniques or any other mechanical or non-mechanical anastomosis method. In some embodiments, the first component 101 is made of a material that enhances cell ingrowth to enhance the biocompatibility of the graft. As such, the material may be a porous EPTFE or woven Dacron material, depending on the case.

[0027] The second component 102 may have a smaller diameter and may be provided with a sewing cuff 103 to allow for easy connection of the first component 101 and the second component 102 by commonly used sutures or any other mechanical or non-mechanical anastomosis method.

[0028] The distal end of second component 102 typically protrudes into and is somewhat concentric with first component 101, forming a groove-shaped circular ring between components 101 and 102. Blood cells may accumulate in this groove, which would define a transition / boundary / seam between the cellular ingrowth region and the smooth, non-cellular ingrowth region, as intended. Furthermore, second component 102 is made of a material that inhibits cellular ingrowth or attachment within its lumen, e.g., a smooth, thin silicone layer; thus, cellular ingrowth would be restricted to first component 101. To further promote continuous ingrowth defined by the smooth, thin layer of cells growing from the blood vessel into first component 101, first component 101 is designed with its rigidity and potentially a bellows structure to act as a shock absorber for any blood pump device that may be attached to component 102. The shock-absorbing means effectively absorbs any flow / pressure-induced axial motion, thus helping to promote continued cell ingrowth at the desired site. As such, pumping device-induced motion would not prevent ingrowth, which could result in continued cell overgrowth, narrowing of the opening, and irregular granular tissue, which could also dislodge and lead to an ischemic event. While ingrowth into the first component 101 is desirable, ingrowth onto the outer surface of the first component 101 must be prevented by a cell-inhibiting surface means, such as a silicone coating, because overgrowth onto the outer surface of the first component 101 could otherwise result in deformation of the target vessel, which could essentially limit the vascular opening near the anastomosis.

[0029] Due to the difference in luminal diameter between the first component 101 and the second component 102, a vortex typically forms at a vortex region 106 located proximal to the junction region of the first component 101 and the second component 102. The vortex region 106 serves as a region to limit continued ingrowth or cell attachment in the vortex region 106.

[0030] In a different embodiment, the present disclosure provides a vascular graft 107 formed from a single or multiple tubular components having, in certain aspects, similar inner diameters. The internal deformation portion 108 can be integral or added later during graft manufacturing to form a "necked-down" region in the lumen of the graft 107. The internal deformation portion 108 acts as a ridge to create a convolution proximal to the graft 107, inhibiting cellular ingrowth, cell attachment, and / or cell deposition. The two sections of the graft 107 separated by the internal deformation portion 108 can be similar or different in biological properties, mechanical properties, and / or physical response to blood contact. The region of the graft 107 distal to the internal deformation portion 108 may be surface treated to inhibit cellular ingrowth, while the proximal region is designed to promote cellular ingrowth from the blood vessel onto the graft.

[0031] In different embodiments, the present disclosure provides a vascular graft 203 formed from one or more sections, e.g., first section 201 and second section 202, that create a single graft possessing, in certain aspects, different biological properties, mechanical properties, and / or physical responses to blood contact. In one embodiment, section 201 is impregnated with silicone rubber to inhibit cell ingrowth, while section 202 is porous / rough in nature to promote ingrowth. The seam between sections 201 and 202 does not include a physical step that prevents any unwanted overgrowth of cells from section 202 onto section 201.

[0032] FIG. 4 illustrates a support stent for a conduit, e.g., for use as a graft with a counterpulsation device (CPD). The conduit includes terminal ports and passageways between the ports that include bulging regions, e.g., spherical sections. In some embodiments, e.g., when used with a CPD, blood may flow through the conduit in alternating directions. Conduit 401 includes a spiral support structure 403 on a first conduit section surface. Conduit 401 includes a spherical section 402 having multiple support structures 404 connected thereto. Support structures 403 and 404 may be constructed of stainless steel wire and connected to the conduit via sutures, according to an exemplary embodiment. Spherical section 402 may be inwardly and outwardly flexible to allow for cleaning of the transition. Spherical section 402 may be manufactured using a graft, such as a 20 mm graft, which is cut and sutured to form the spherical shape illustrated in FIG. 4.

[0033] The conduit may be supported by a stent structure. In some embodiments, the support structure includes a first portion including one or more support struts shaped to form a bulbous portion. In some embodiments, the outer surface of the material of the bulbous portion of the conduit (e.g., PTFE or other suitable material) may be attached to the struts. In some embodiments, this arrangement causes the bulbous portion of the conduit to flex during use, for example, to facilitate cleaning of the conduit passageway.

[0034] In some embodiments, the support stent may include a second portion that supports a non-spherical portion of the conduit (e.g., a portion having a substantially constant cross-section). In some embodiments, the second portion may include a spiral-shaped support structure. In some embodiments, the struts of the first portion of the support structure may be connected to the second portion of the support structure.

[0035] The support stent may be made of any suitable material (eg, a biocompatible material having sufficient structural properties to support the conduit), including, for example, stainless steel or a shape memory material such as Nitinol.

[0036] In some embodiments, the conduit may be formed with one or more sections, e.g., a first section and a second section, creating a single graft possessing different biological properties, mechanical properties, and / or physical responses to blood contact.

[0037] In one embodiment, the first section is impregnated with silicone rubber to inhibit cell ingrowth, while the second section is porous / rough to promote ingrowth. The join between the sections does not include a physical step, which prevents any unwanted overgrowth of cells from the first section to the second section. Other embodiments may feature other transition shapes.

[0038] In some embodiments, the first area may correspond to one portion of the sphere, while the second area corresponds to another portion, or vice versa.

[0039] One form of counterpulsation system usable with embodiments of the invention disclosed herein is shown in FIG. 5. Here, pump 10 is implanted in a patient's right pacemaker pocket. Blood fills pump 10 on one side, and air or other fluid fills a sac or pouch (not shown) on the other side of pump 10. An air drive line 12 passes from the pacemaker pocket to a skin exit port 14, so that the entire pump 10 is under the skin and can remain there for extended periods. After exiting the skin, drive line 12 is attached to a small air drive unit 16 that controls compressed air to periodically enter and exit pump 10. The cavity of pump 10 may be formed by a sac or pouch. As the heart beats, the cavity fills with air (less cardiac work to pump blood out) and empties to return blood to the circulatory system (greater flow rate for the patient). Pump 10 is attached to the circulatory system by a conduit 20. Conduit 20 moves blood between the patient's circulatory system and pump 10. This situation allows the patient to have long-term counterpulsation with full mobility, which is a great advantage for patients with severe and potentially irreversible cardiac dysfunction, as they can lead relatively normal lives except for the need to carry around a small, battery-powered controller 16.

[0040] As mentioned above, blood is periodically pumped into and out of pump 10 through a conduit 20 connected to the circulatory system. There are several considerations related to the implantation and use of this conduit 20. First, while almost all conduits allow blood to flow in one direction, this conduit 20 changes direction twice with each heartbeat as pump 10 fills and empties with each cardiac cycle. This presents several significant problems, discussed below. A second potential problem with a conduit in this situation is that it is typically sutured to the subclavian artery 22 or axillary artery, which are located below the clavicle and often quite deep, making it technically difficult for a surgeon to suturing the end of conduit 20 to the artery 22.

[0041] Problems with bidirectional flow conduits relate to the reaction of blood and tissue at the interface with the synthetic material, which depends on the direction of blood flow. For example, many medical devices, such as blood pumps, are connected to the patient's circulatory system with synthetic graft materials, such as Dacron® or polyester materials like advanced porous Teflon® (ePTFE), that promote tissue or cell ingrowth. The inside of the blood pump is generally smooth and constructed of metal or plastic. When blood flows from a smooth metal or plastic blood pump to a synthetic graft (e.g., polyester), the interface where the pump meets the conduit (from plastic or metal to synthetic graft) is a stable junction, and there are few problems when blood flows forward through this junction.

[0042] Unfortunately, experience has shown that when blood flows in reverse, from an artificial graft, such as polyester, toward a blood pump with a smooth surface, deposits of blood components, including platelets and fibrin, adhere to the junction of the two materials, primarily on the surface of the artificial graft, overhanging the inlet to the pump. These deposits, particularly platelets, tend to attract more blood components, resulting in large, often friable deposits at the junction. These deposits can break off from the junction, enter the blood pump, and be delivered through the patient's circulatory system. These deposits can flow anywhere, but if they reach the arteries to the brain, they can cause a stroke. For this reason, many successful blood pumps employ smooth artificial conduits (e.g., silicone or urethane) to allow blood to enter the pump.

[0043] The problem with counterpulsation is that blood flows alternately in both directions. One solution is to use a smooth silicone or urethane conduit, which can create a stable junction between the pump and the conduit, where blood enters the pump. This solves the problem at the inlet to the pump. However, when the silicone material is anastomosed (sewn) to the artery, a large amount of blood material (fibrin and platelets) deposits at the junction. Therefore, simply replacing the inlet conduit with a silicone surface is not sufficient. While it is tempting to simply have a silicone conduit and add a textile extension, this simply transfers the problems that occur at the junction between the pump and the rough textured surface of the graft to the junction between the graft and the silicone tubing or cannula.

[0044] FIG. 8 shows a cross-section of one exemplary solution. The subclavian artery 22 is shown at the top of the figure. A "foam" or bulged region 24 made of Dacron®, Teflon®, or other material is sutured to the artery 22. A conduit section 26 made of silicone or other smooth material is connected to the other side of the bulged region 24. Rather than a direct bond, a special interface is created. The smooth silicone surface section 26 extends a few millimeters into the bulged region 24 made of fiber or other material by a tip section 26a. The wall of the silicone tip section 26a does not contact the fiber or material of the bulged region or foam section 24. This prevents contact between the silicone and the fiber (or between a smooth section and a rough section).

[0045] The heart valve was constructed in a configuration that avoids tissue ingrowth into the heart valve by creating ridges so that there is no continuous connection between the fiber surface and the smooth surface. The ridges prevent tissue from growing into the joints and creating points for platelets and fibrin to adhere. The use of small washer materials may also be useful. Figure 12 shows a small washer 28 around the base of the tip 26a that may help prevent adhesion of blood components.

[0046] 13 illustrates this placement of a "bubble" or bulging region 24a of graft material located away from the anastomosis. In particular, bulging region 24a is connected to or includes extension 24b that is anastomosed to artery 22. Other features may be as previously described.

[0047] Figures 14A and 14B show that a similar arrangement can be made at the joint of pump 10. Here, the plastic, metal, or other smooth surface of joint or tip portion 10a of pump 10 is separated from the rough surface of the expanded graft material by a foam interface 24a. An extension 24b of graft material is sutured to artery 22 as previously described (Figure 13). Another extension 24c at the opposite end can cooperate with a suitable connector 28 to facilitate connection to pump interface or tip portion 10a. Junction or interface 10a serves as an inlet / outlet port that extends into, but does not typically contact, the graft material 24a in use.

[0048] These devices with foam or bulging portions can be fabricated in one piece. As previously mentioned, the subclavian artery 22 is located quite deep, and the incision is small. Therefore, a surgeon attempting to suture a graft with foam or bulging portions to it would be working in a deep hole. The foam or bulging portions at the end of the graft would obstruct the view into the artery. It would be useful to avoid this problem while also meeting the need to maintain a linear arrangement where smooth and rough surfaces do not directly contact each other.

[0049] Such a solution is shown in Figures 6 and 7. Here, a graft element made of a material such as those described above is sutured to the artery. The graft element 30 has a flange 32 at one end. The element 30 is small and easy to move around, so it does not obstruct the surgeon's view. Figure 7 shows how easily this element 30 can be sutured around the opening 22a in the artery 22.

[0050] FIG. 8 shows how the joint between the silicone material portion 26 of the conduit 20 and the graft element 30 is reformed, for example, when a lip or flange 34 of the suture or graft material of the conduit portion 26 is attached to a flange 32 on the element 30 already anastomosed to the artery 22.

[0051] Figure 9 shows how the two flanges 32, 34 are sutured together. This is a very easy anastomosis to perform.

[0052] It should be understood that the flanges 32, 34 may be connected not only by sutures, but also by staples, clips, glue, clamps, and the like.

[0053] FIG. 10A shows a vertical cross section of the two flanges 32, 34 when they are joined together.

[0054] 10B shows how the bubble or bulged connector 30 need not be flat, i.e., it can be angled. Also, the connector 30 need not be a generally spherical bubble as shown elsewhere herein. All that matters is that the bulged area avoids direct contact between the silicone and the graft surface (i.e., smooth and rough flow surfaces) at the joint during use.

[0055] The bubble or bulged area 36 is very useful because it allows the graft to move or "pivot" within the bubble 36 but not contact the walls of the bubble 36.

[0056] FIG. 10B also shows that clips or staples 38 attach connector 30 to artery 22 and attach flanges 32, 34 together.

[0057] The conduit section 26 need not be entirely silicone. It may have any inner core that provides a compatible surface for exposed blood. For example, the interior may be metal, have metal spiral reinforcement, or the like. It may also have a graft material such as ePTFE or other polyesters on the interior.

[0058] The smooth surface does not have to be silicone; it is used as a representation of a smooth surface. The surface may be metal or plastic (as is the case in the pump connection shown in Figures 14A and 14B).

[0059] 11 shows a bubble or bulged area 40 constructed by "splitting" the bubble in the center of the hemisphere. Formally, the joint 42 is equally possible anywhere in this arrangement, and this location on the hemisphere is merely exemplary.

[0060] Alternatively, a more complete foam mold may be fabricated to perform the same function, and the end of a silicone cannula inserted into the defect.

[0061] It should be noted that the terms used are essentially smooth surfaces (silicone, plastic, metal) and rough or textured surfaces (Dacron, Teflon, ePTFE). It is also possible to have tightly woven or knitted materials, usually called fabrics, that can function as smooth surfaces.

[0062] It is also possible to make a tightly woven polyester that behaves like a smooth surface. A tightly woven sutureable graft can be placed directly in contact with a silicone surface without any bubbles or steps to obstruct it.

[0063] It is also important to avoid collapse of the conduit, since it is placed under the skin and can be crushed when the patient lies on it. In this case, reinforcement of the conduit with spirals or rings made of plastic or wire can be used. Additionally, additional thickness of polymer or plastic can be added to make them stronger.

[0064] In various embodiments, any of the devices and techniques described herein may be used in any suitable combination with the devices and techniques described in the accompanying documentation.

[0065] As used herein, the terms "approximately," "about," "substantially," and similar terms are intended to have broad meanings consistent with common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure belongs. It should be understood by those of ordinary skill in the art upon viewing this disclosure that these terms are intended to allow for the description of certain features being described without limiting the scope of these features to the precise numerical ranges provided. Thus, these terms should be interpreted to indicate that insubstantial or insignificant modifications or variations of the subject matter being described are considered to be within the scope of the present disclosure.

[0066] It should be noted that the term "exemplary" as used herein to describe various embodiments is intended to indicate that such embodiments are possible examples, representations, and / or illustrations of possible embodiments (and that such terms are not intended to imply that such embodiments are necessarily particular or best examples).

[0067] For purposes of this disclosure, the term "coupled" means the direct or indirect joining of two members to one another. Such joining may be fixed or movable in nature. Such joining may be achieved with two members integrally formed with one another as a single unit, or with two members and optional additional intermediate members, or with two members attached to one another. Such joining may be permanent in nature, or may be removable or releasable in nature.

[0068] It should be noted that the orientation of various elements may differ according to other exemplary embodiments, and that such variations are intended to be encompassed by the present disclosure. It is recognized that features of the disclosed embodiments may be incorporated into other disclosed embodiments.

[0069] It is important to note that the construction and arrangement of spring systems or their components as shown in the various exemplary embodiments are exemplary only. While only a few embodiments are described in detail in this disclosure, those skilled in the art upon viewing this disclosure will readily recognize that many modifications (e.g., changes in size, dimensions, structure, shape and proportions of various elements, parameter values, mounting arrangements, use of materials, color, orientation, etc.) are possible without substantially departing from the novel teachings and advantages of the disclosed subject matter. For example, elements shown as integrally formed may be constructed from multiple parts or elements, element positions may be reversed or otherwise changed, and the nature or number of individual elements or positions may be modified or changed. The order or arrangement of any process or method steps may be changed or rearranged according to alternative embodiments. Other substitutions, modifications, variations, and omissions may also be made in the design, operating conditions, and arrangement of the various exemplary embodiments without departing from the scope of the present disclosure.

[0070] All literature and similar materials cited in this application, including but not limited to patents, patent applications, articles, books, papers, and web pages, are expressly incorporated by reference in their entirety, regardless of the format of such literature and similar materials. In the event that one or more of the incorporated literature and similar materials differs from or contradicts this application, including but not limited to defined terms, term usage, descriptions of technology, etc., this application controls.

[0071] While various embodiments of the present invention have been described and illustrated herein, those skilled in the art will readily envision various other means and / or structures for performing the functions and / or obtaining the results and / or one or more advantages described herein, and each such variation and / or modification is deemed to be within the scope of the embodiments of the present invention described herein. More generally, those skilled in the art will readily recognize that all parameters, dimensions, materials, and configurations described herein are intended to be exemplary, and that the actual parameters, dimensions, materials, and / or configurations will depend on the specific application for which the teachings of the present invention are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the present invention described herein. Accordingly, it should be understood that the foregoing embodiments are presented by way of example only, and that, within the scope of the appended claims and their equivalents, embodiments of the present invention may be practiced otherwise than as specifically described and claimed. The inventive aspects of the present disclosure are directed to each individual feature, system, article, material, kit, and / or method described herein. Furthermore, any combination of two or more such features, systems, articles, materials, kits, and / or methods, if such features, systems, articles, materials, kits, and / or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.

[0072] Additionally, the techniques described herein may be embodied as methods, at least one example of which is provided. Acts performed as part of a method may be ordered in any suitable manner. Thus, even if acts are shown as sequential in an illustrative embodiment, embodiments may be constructed in which acts are performed in an order different from that illustrated, which may include performing some acts simultaneously.

[0073] All definitions defined and used herein should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0074] The indefinite articles "a" and "an," as used in this specification and the appended claims, unless clearly indicated to the contrary, should be understood to mean "at least one."

[0075] The phrase "and / or," as used in this specification and the appended claims, should be understood to mean "either or both" of the elements so conjoined, i.e., elements that are present conjunctively in some cases and disjunctively in other cases. Multiple elements listed with "and / or" should be construed in the same manner, i.e., "one or more" of the elements so conjoined. Other elements, whether related or unrelated to those elements specifically identified, may optionally be present other than the elements specifically identified by the "and / or" clause. Thus, as a non-limiting example, a reference to "A and / or B," when used in conjunction with open-ended language such as "comprising," refers, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); and so forth.

[0076] As used herein and in the appended claims, "or" should be understood to have the same meaning as "and / or" as defined above. For example, when separating items in a list, "or" or "and / or" shall be construed as inclusive, i.e., the inclusion of at least one, including more than one, of some or a list of elements, and optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as "only one of" or "exactly one of," or, when used in the appended claims, "consisting of," shall refer to the inclusion of exactly one element of some or a list of elements. Generally, the term "or" as used herein shall only be construed to indicate exclusive alternatives (i.e., "one or the other, but not both") when preceded by exclusive terms such as "either," "one of," "only one of," or "exactly one of." When used in the appended claims, "consisting essentially of" shall have its ordinary meaning as used in the field of patent law.

[0077] As used in this specification and the appended claims, the phrase "at least one" in reference to a list of 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 and every element specifically listed in the list of elements, and not excluding any combinations of elements in the list of elements. This definition also allows for the optional presence of elements other than those specifically identified in the list of elements to which the phrase "at least one" refers, whether related or unrelated 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 to, in one embodiment, at least one A, optionally including more than one, with no B present (and optionally including elements other than B); in another embodiment, at least one B, optionally including more than one, with no A present (and optionally including elements other than A); in yet another embodiment, at least one A, optionally including more than one, and at least one B, optionally including more than one (and optionally including other elements); etc.

[0078] In the appended claims and in the above specification, all transitional phrases such as "comprising," "including," "holding," "having," "containing," "involving," "holding," "consisting of," and the like, shall be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases "consisting of" and "consisting essentially of" shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.

[0079] The appended 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 may 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 appended claims and their equivalents are claimed.

Claims

1. 1. A vascular graft comprising at least one conduit having a first conduit portion and a second conduit portion, the first conduit portion has a substantially constant diameter and connects to a first end of a second conduit portion, the second end of the second conduit portion including an opening configured to connect to a blood vessel; the distal end of the first conduit portion extends to the second conduit portion, the second conduit portion being a connector having a bulged portion and a connector portion, the bulged portion configured to allow the first conduit portion to swivel within the bulged portion without contacting an interior of the bulged portion; the first conduit portion includes a first material having a smooth surface, and the second conduit portion includes a second material different from the first material, the second material including a rough surface; Vascular graft.

2. The vascular graft of claim 1, wherein the first material comprises silicone rubber.

3. The vascular graft of claim 1, wherein the second material comprises porous ePTFE.

4. The vascular graft of claim 1, wherein the second material comprises a woven polyester material.

5. The vascular graft of claim 1 , wherein the at least one conduit is configured to connect to a blood flow assist system.

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