Description:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(Section 10 and Rule 13)

1. TITLE OF THE INVENTION:
OCCLUDER
2. APPLICANT:
Meril Corporation (I) Private Limited, an Indian company of the address Survey No. 135/139, Muktanand Marg, Bilakhia House, Pardi, Vapi, Valsad-396191 Gujarat, India.

The following specification particularly describes the invention and the manner in which it is to be performed:

 
FIELD OF INVENTION
[001] The present disclosure relates to an occluder implant. More particularly, the present disclosure relates to an occluder for the left atrial appendage.
BACKGROUND OF INVENTION
[002] Atrial fibrillation is a heart condition where the upper chamber of the heart known as the atrium, beats irregularly. This condition is most often caused due to dysfunction of any of the valves in the heart. However, in some cases, this condition may be caused without any problem in the heart valves. Such a condition is called non-valvular atrial fibrillation.
[003] A person suffering from non-valvular atrial fibrillation may experience symptoms such as heart palpitation, shortness of breath, fatigue, dizziness, chest discomfort, and so forth. However, the primary concern with non-valvular atrial fibrillation is the increased risk of stroke. The irregular rhythm of the heart can lead the blood to pool in the top left chamber of the heart, known as the left atrium, and form blood clots. If these clots travel to the brain, they can cause a stroke.
[004] The treatment for non-valvular atrial fibrillation may include the use of medicines to regulate the irregular rhythm of the heart. Change in lifestyle can also help to manage the symptoms of non-valvular atrial fibrillation. Alternatively, surgical procedures such as implanting occluders may be used to treat non-valvular atrial fibrillation. Occluders may cover the left atrial appendage (an ear-shaped sac on the wall of the left atrium, and a common place for blood clot formation in the heart) to reduce the chances of blood clot formation thereby, minimizing the chances of travel of the blood clot in the blood flow, which may further decrease the chances of stroke.
[005] However, the occluders known in the art may have bulky structure containing high metallic content. The metal of the occluder after a period of time may cause infection that may lead to severe repercussions. The occluders may also have an increased risk of migration from the implantation site that may increase chances of clots passing through even after implantation of an occluder, a condition known as peri device leakage.
[006] Therefore, there arises a need for an occluder to overcome the shortcomings of the occluders known in the art.
SUMMARY OF INVENTION
[007] Particular embodiments of the present disclosure are described herein below with reference to the accompanying drawings, however, it is to be understood that the disclosed embodiments are merely examples of the disclosure, which may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure.
[008] The present invention relates to an occluder for an atrial appendage, the occluder comprising a frame, and a membrane. The frame includes a hub and a plurality of segments radially coupled to the hub. Each segment of the plurality of segments includes a substantially horizontal section substantially parallel to the horizontal axis of the occluder, a substantially vertical section including an increasingly outward curvature with respect to a longitudinal axis of the occluder; and a connecting section coupling the substantially horizontal section and the substantially horizontal section. The membrane is attached to the plurality of segments. The membrane is configured to seal the plurality of segments and spaces between adjacent plurality of segments.
[009] The foregoing features and other features as well as the advantages of the invention will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures
BRIEF DESCRIPTION OF DRAWINGS
[0010] The summary above and the detailed description of descriptive embodiments, is better understood when read in conjunction with the apportioned drawings. For illustration of the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the disclosure is not limited to specific methods and instrumentality disclosed herein. Moreover, those in the art will understand that the drawings are not to scale.
[0011] Fig. 1 depicts an occluder 100 implanted on a left atrial appendage (or LAA) 10 of a human heart, in accordance with an embodiment of the present disclosure.
[0012] Fig. 2 depicts an isometric view of the occluder 100, in accordance with an embodiment of the present disclosure
[0013] Fig. 3 depicts an isometric view of a frame 110, in accordance with an embodiment of the present disclosure.
[0014] Fig. 4 depicts an isometric view of a segment 113, in accordance with an embodiment of the present disclosure.
[0015] Fig. 5 depicts a cross-sectional view of the frame 110, in accordance with an embodiment of the present disclosure.
[0016] Fig. 6 depicts an isometric view of a membrane 130, in accordance with an embodiment of the present disclosure.
[0017] Fig. 7 depicts the occluder 100 being delivered in the human anatomy via a delivery catheter, in accordance with an embodiment of the present disclosure.
[0018] Fig. 8 depicts a three-dimensional monolayer of endothelial cells (or layer 11) formed on the occluder 100 in accordance with an embodiment of the present embodiment.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0019] Prior to describing the disclosure in detail, definitions of certain words or phrases used throughout this patent document will be defined: the terms "include" and "comprise", as well as derivatives thereof, mean inclusion without limitation; the term "or" is inclusive, meaning and/or; the phrases "coupled with" and "associated therewith", as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have a property of, or the like. Definitions of certain words and phrases are provided throughout this patent document, and those of ordinary skill in the art will understand that such definitions apply in many, if not most, instances to prior as well as future uses of such defined words and phrases.
[0020] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including,” “comprising,” “having,” and variations thereof mean “including but not limited to” unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive and/or mutually inclusive, unless expressly specified otherwise. The terms “a,” “an,” and “the” also refer to “one or more” unless expressly specified otherwise.
[0021] Although the operations of exemplary embodiments of the disclosed method may be described in a particular, sequential order for convenient presentation, it should be understood that the disclosed embodiments can encompass an order of operations other than the particular, sequential order disclosed. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Further, descriptions and disclosures provided in association with one particular embodiment are not limited to that embodiment, and may be applied to any embodiment disclosed herein. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed system, method, and apparatus can be used in combination with other systems, methods, and apparatuses.
[0022] Furthermore, the described features, advantages, and characteristics of the embodiments may be combined in any suitable manner. One skilled in the relevant art will recognize that the embodiments may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments. These features and advantages of the embodiments will become more fully apparent from the following description and apportioned claims, or may be learned by the practice of embodiments as set forth hereinafter.
[0023] The present disclosure relates to an occluder. In an embodiment, the occluder of the present disclosure is implanted inside the heart to cover the left atrial appendage (LAA) say, for the treatment of non-valvular atrial fibrillation. The occluder is compatible with and suitable to all types of LAA anatomy. The occluder of the present invention minimizes or prevents migration of the blood clots from the Left Atrial Appendage (LAA) to the rest of the circulatory system and therefore, minimizes the risk of, or prevents transient ischemic attack, a stroke, or a blood vessel blockage called an embolism.
[0024] The device of the present disclosure is provided with a self-expandable frame at least partially covered with a membrane. The occluder is retrievable and can be retrieved using a suitable retrieval system. The occluder is repositionable and can be repositioned in case if the occluder is displaced from its implanted position. The frame of the occluder promotes atraumatic deployment at the LAA. The occluder is provided with a plurality of hooks that help the device to engage with the surrounding tissue of the LAA thereby, preventing device migration and providing long-term stability to the occluder after implantation.
[0025] The frame provides high radial strength to the occluder to withstand high blood flow rates. The membrane partially covers the frame thereby allowing the occluder to cover the LAA. The shape of the occluder provides a complete coverage of the LAA thereby minimizing any chances of peri-device leakage. The membrane of the occluder may promote uniform and fast reendothelialization after deployment at the target site. The material of the membrane required to cover the frame is very less. Hence, the chance of device related thrombosis is reduced as excess material of the membrane may obstruct the blood flow causing thrombus formation. Reendothelialization plays a vital role in supply of oxygen and other nutrients to the tissues in the proximity of the occluder (such as, parts of the LAA) which are essential for health rhythmic movement of the whole heart. Optionally, the occluder may be coated with an anti-thrombotic coating that lowers the chances of device-related thrombosis.
[0026] Now referring to the figures, Fig. 1 depicts an occluder 100 for an atrial appendage implanted on a left atrial appendage (or LAA) 10 of a human heart.
[0027] Fig. 2 depicts a perspective view of the occluder 100 which includes a proximal end 100a and a distal end 100b. The occluder 100 may have a radially constricted state and a radially expanded state. The occluder 100 is radially expandable from the radially constricted state to the radially expanded state. In an exemplary embodiment, the occluder 100 is self-expandable from the radially constricted state to the radially expandable state, the self-expansion enabled by the structural construction, and the material properties of the occluder 100. A delivery sheath (not shown) may help constrain the occluder 100 in its radially constricted state, during the implantation or implant retrieval procedures. The occluder 100 remains in a radially constricted state while it is carried to the LAA. The occluder 100 may be radially expanded by either retracting the delivery sheath from over the occluder 100 or by pushing the occluder 100 out of the delivery sheath.
[0028] The occluder 100 includes a frame 110, and a membrane 130. The frame 110 defines the structure of the occluder 100. The frame 110 may be at least partially covered with the membrane 130. In an embodiment, the membrane 130 may be fixedly coupled to the frame 110. The membrane 130 may be coupled to the frame 110 using stitching hooking, shrinking, and, the like. Alternately, the membrane 130 may be a separate component and coupled to the frame 110 via suturing, stitching etc. In an embodiment, the membrane 130 is coupled to the frame 110 using stitching.
[0029] In accordance with Fig. 3, the frame 110 includes a hub 111 and a plurality of segments 113. The plurality of segments 113 includes at least two or more segments 113. In the radially expanded state of the frame 110, the segments 113 exert a radial resilient force on the walls of the LAA providing improved positioning on the implantation site thereby reducing the risk of displacement of the occluder 100 form the implantation site (i.e., LAA).
[0030] The hub 111 may be made of a biocompatible material including, but not limited to nitinol, stainless steel, cobalt-chromium, tantalum, and so forth. The hub 111 may have a predefined shape including but not limited to a cylinder, square, pentagon, hexagon, and so forth. In an embodiment, the hub 111 has a cylindrical shape. The diameter of the hub 111 may range between 2.0 mm and 4.0 mm. In an embodiment, the diameter of the hub 111 is 3.2 mm.
[0031] The hub 111 includes a proximal end 111a and a distal end 111b. To the distal end 111b, proximal ends of the plurality of segments 113 are coupled. In an embodiment, the segments 113 are fixedly coupled with the hub 111, hence the segments 113 are held together by the hub 111 at their proximal ends. The segments 113 and the hub 111 may be fixedly coupled using a method including, but not limited to welding, soldering, brazing, laser welding, and the like. In another embodiment, the segments 113 and the hub 111 are coupled together such that entire frame 110 is fabricated as a single structure.
[0032] In an embodiment, each segment 113 is positioned on the hub 111 at an equal distance from the other. Alternately, the segments 113 may be arranged in a predefined pattern including without limitation, non-uniform distance between two consecutive segments 113, alternate sequences of closely placed and distantly placed segments 113, etc. The segments 113 may be arranged radially around a longitudinal axis of the occluder 100. The radial arrangement of the segments 113 makes the frame 110 radially symmetrical about a longitudinal axis of the occluder 100.
[0033] In an embodiment, the plurality of segments 113, coupled to the hub 111 define a bell shape or flower-like shape of the occluder 100. Due to this arrangement of the segments 113, the occluder 100 has high radial strength thereby, minimizing the chances of deformation of the occluder 100 under the systolic and diastolic compression and expansion of the cardiac muscles.
[0034] The segment 113 may be fabricated from a sheet of material using, laser cutting method. In another embodiment, other methods may be used for the fabrication of the segment 113 including, but not limited to molding, casting, shape setting, and so forth. Further details of the segment 113 are explained in the context of Fig. 4.
[0035] The frame 110 may be made of a biocompatible material including, but not limited to nitinol, stainless steel, cobalt-chromium, tantalum, and the like. In an embodiment, the frame 110 is made of nitinol.
[0036] Fig. 4 shows the segment 113. The segment 113 includes a proximal end 113a and a distal end 113b. The proximal end 113a is defined by two struts 116a, 116b, joined together or at least placed in close proximity to each other. In an embodiment, the two struts 116a and 116b are placed in close proximity. The segment 113 is coupled to the hub 111 via the two struts 116a and 116b of the segment 113 using a coupling method including, but not limited to welding, arc welding, soldering, brazing, laser welding, and so forth. It is to be noted that the two struts 116a, 116b may be two ends of a single strut or two or more different struts coupled together at one end and free at other.
[0037] Each segment 113 includes a substantially horizontal section 115a, a connecting section 115b and a substantially vertical section 115c. The substantially horizontal section 115a as well as the connecting section 115b, is positioned towards the distal end 100b of the occluder 100 while the substantially vertical section 115c is positioned towards the proximal end 100a of the occluder 100.
[0038] In the substantially horizontal section 115a, the two struts 116a and 116b define a predefined shape, for example, a semi-circular shape, an arc, etc. In the depicted embodiment, the struts define a substantial D-shape (also referred as D-shaped struts).
[0039] Further, the struts two struts 116a and 116b of the substantially horizontal section 115a are positioned substantially parallel to the horizontal axis of the occluder 100 making the substantially horizontal section 115a parallel to the horizontal axis of the occluder 100. The substantially horizontal sections 115a of all the segments 113 are arranged in such a manner that they form a circular disc. This radial arrangement of the substantially horizontal sections 115a of the plurality of segments 113 provides a large coverage area.
[0040] The connecting section 115b joins the substantially horizontal section 115a, and the substantially vertical section 115c. The struts in the connecting section 115b may be substantially L-shaped (also referred as L-shaped struts). Due to this connection, the width of the substantially horizontal section 115a is at least three times more than the width of the substantially vertical section 115c at the point of connection of the latter with the hub 111. The variation in the width of the substantially horizontal section 115a and the substantially vertical section 115c provides better circumferential expansion and proper wall apposition to the occluder 100.
[0041] The substantially vertical section 115c attains an increasingly outward curvature with respect to a longitudinal axis of the occluder 100 from the proximal to the distal end of the respective segment 113 (clearly depicted in Fig. 5). Specifically, the outward curvature begins from nearly the proximal end 113a of the segment 113 and extends till the connecting section 115b. The curvature of the substantially vertical section 115c facilitates uniform distribution of the radial stress thereby increasing the durability of the occluder 100.
[0042] In an embodiment, the substantially horizontal section 115a, the connecting section 115b and the substantially vertical section 115c are hollow and defined by the two struts 116a and/or 116b as explained above. Due to this, the amount of metallic material used is minimal.
[0043] At least one segment 113 is provided with a hook 114 at the distal end 113b. For example, alternate segments 113 may include the hook 114 or every segment 113 may include the hook 114, etc. The hook 114 is configured to securely, yet removably attach the segment 113 (and consequently the occluder 100) to the walls of the LAA. The hook 114 may be fabricated using the same material as the segment 113. In an embodiment, the hook 114 has a cured body.
[0044] The distal end of the hook 114 may be pointed. The pointed end holds the tissue of the implantation site to provide a firm grip to the occluder 100 on the implantation site. The occluder 100 may be exposed to high rates of blood flow which may displace or migrate the occluder 100 from the implantation site. The hook 114 helps to prevent migration against such forces.
[0045] In an embodiment, the distal end of the hook 114 is fixedly coupled to the segment 113. The hook 114 may be coupled to the distal end 113b of the segment 113 using welding, arc welding, soldering, brazing, laser welding, shape setting, and so forth. In an embodiment, the hook 114 is coupled to the segment 113 using shape setting.
[0046] Fig. 6 depicts the membrane 130 of the occluder 100. In an embodiment, the membrane 130 is fixedly attached to the plurality of segments 113. The membrane 130 is configured to seal the plurality of segments 113 and the spaces between adjacent plurality of segments 113. The membrane 130 is provided with an anti-thrombotic coating that aids or enhances reendothelialization, namely, formation of a three-dimensional monolayer 11 of endothelial cells on the occluder 100 (shown in Fig. 8).
[0047] The membrane 130 may be made of a suitable fabric including but not limited to polyethylene terephthalate (PET), polyester, Dacron, polytetrafluoroethylene (PTFE), pericardium tissue, expanded polytetrafluoroethylene (ePTFE), and so forth. In an embodiment, the fabric used for making the membrane 130 is PET.
[0048] The membrane 130 includes a central cone 130a and a disc 130b with a hollow center stretched around the central cone 130a. The central cone 130a is disposed towards the proximal end 100a of the occluder 100. The shape of the central cone 130a corresponds to the proximal portion of the frame 110. The central cone 130a may define a conduit. The conduit may be in fluid coupling with the hub 111. The conduit may also be configured to house the proximal portion of the frame 110. The conduit may have an internal diameter. The internal diameter may correspond to the proximal portion of the frame 110. The internal diameter of the conduit may be between 2 mm and 6 mm. The conduit may be substantially parallel to the longitudinal axis of the occluder 100.
[0049] The disc 130b of the membrane 130 is disposed towards the distal portion of the segments 113. The disc 130b may be substantially perpendicular to the longitudinal axis of the occluder 100. The diameter of the disc 130b may range between 14 mm and 42 mm. In an embodiment, the central cone 130a and the disc 130b are made from a single piece of fabric. Alternatively, the central cone 130a and the disc 130b may be made from two different pieces of fabric.
[0050] The membrane 130 may be covered with an anti-thrombotic coating which lowers the chances of thrombus formation. The materials used for the coating include without limitation perfluoroalkoxy alkane, polytetrafluoroethylene, etc.
[0051] During a medical procedure, the occluder 100 of the present disclosure may be implanted at the target site using a minimal invasive technique, such as trans-catheterization. The trans-catheterization or transcatheter delivery of the occluder 100 is carried out by using a catheter 200 (shown in Fig. 7).
[0052] The occluder 100 is pre-loaded on the catheter 200. In an exemplary embodiment, a distal end of a delivery shaft 210 may be coupled to the hub 111 of the occluder 100. In an exemplary embodiment, the hub 111 is provided with threads. The one or more threads of the hub 111 are configured to mate with the corresponding one or more threads on the outer surface of the delivery shaft 210 of the transcatheter. The screw-type mechanism ensures easy attachment/detachment of the occluder 100 from the delivery shaft 210 and prevents slipping of the occluder 100 during loading and deployment of the occluder 100.
[0053] During the medical procedure, the delivery shaft 210 may be loaded inside of the catheter 200 and is minimally invaded into the patient’s body via an appropriate vascular access point, e.g., through the transfemoral groin of a patient. The catheter 200 is navigated to the target site (i.e., LAA of the heart) with the help of a guide wire (not shown). Fluoroscopic imaging techniques may be used to guide and monitor the advancement of the catheter 200 during the procedure.
[0054] Once the catheter 200 is positioned at the target site, a membrane sheath of the catheter 200 is withdrawn. The occluder 100 is detached from the delivery shaft 210 and it self-expands to its original configuration. The occluder 100 may be implanted at the target site i.e. Left Atrial Appendage (LAA) by unscrewing the distal end of the delivery shaft 210. Once the device is deployed at the LAA, the catheter 200 and the delivery shaft 210 are manually recaptured.
[0055] The scope of the invention is only limited by the appended patent claims. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present invention is/are used. , Claims:WE CLAIM:
1. An occluder (100) for an atrial appendage, comprising:
a. a frame (110) including a hub (111) and a plurality of segments (113), proximal end of each segment (113) coupled to the hub (111), each segment (113) of the plurality of segments (113) includes:
i. a substantially horizontal section (115a) substantially parallel to the horizontal axis of the occluder (100),
ii. a substantially vertical section (115c) including an increasingly outward curvature with respect to a longitudinal axis of the occluder (100); and
iii. a connecting section (115b) coupling the substantially horizontal section (115a) and the substantially horizontal section (115c); and
b. a membrane (130) attached to the plurality of segments (113), the membrane (130) configured to seal the plurality of segments (113) and spaces between adjacent plurality of segments (113).
2. The occluder (100) as claimed in claim 1, wherein the occluder (100) further includes a plurality of hooks (114) disposed at a distal end (113b) of at least one of the plurality of segments (113).
3. The occluder (100) as claimed in claim 1, wherein the proximal end (113a) of the segment (113) is defined by two struts 116a and 116b joined together or at least placed in close proximity with each other.
4. The occluder (100) as claimed in claim 1, wherein the plurality of segments (113) define a bell shape or flower-like shape of the occluder 100.
5. The occluder (100) as claimed in claim 1, wherein width of the substantially horizontal section (115a) is at least three times more than width of the substantially vertical section (115c) at the point of connection of the latter with the hub 111.
6. The occluder (100) as claimed in claim 1, wherein the substantially horizontal section (115a) includes a substantially D-shaped strut.
7. The occluder (100) as claimed in claim 1, wherein the connecting section (115b) includes substantially L-shaped struts.
8. The occluder (100) as claimed in claim 1, wherein the substantially horizontal section (115a), the connecting section (115b) and the substantially vertical section (115c) are hollow.
9. The occluder (100) as claimed in claim 1, wherein the membrane (130) includes a central cone (130a), and a disc (130b) with a hollow center.
10. The occluder (100) as claimed in claim 1, wherein the central (cone 130a) defines a conduit, fluid coupled with the hub (111), configured to house the proximal portion of the frame (110).
11. The occluder (100) as claimed in claim 1, wherein the disc (130b) is substantially perpendicular to the longitudinal axis of the occluder (100).
12. The occluder (100) as claimed in claim 1, wherein the frame (110) is radially symmetrical about the longitudinal axis of the occluder (100).
13. The occluder (100) as claimed in claim 1, wherein the frame (110) is constructed from Nitinol.
14. The occluder (100) as claimed in claim 1, wherein the membrane (130) is formed of one or more of polyethylene terephthalate (PET), polyester, polytetrafluoroethylene (PTEF), and pericardium tissue.
15. The occluder (100) as claimed in claim 1, wherein the membrane (130) further comprises an anti- thrombotic coating.