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:
STENT IMPLANT

2. APPLICANT:
Meril Life Sciences Pvt Ltd., an Indian company of the Survey No. 135/139 Bilakhia House, Muktanand Marg, Chala, Vapi-Gujarat 396191, India.

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

FIELD OF INVENTION
[1] The present disclosure relates to a medical implant. More particularly, the present disclosure relates to a stent implant.
BACKGROUND OF INVENTION
[2] Wide-neck aneurysms, intracranial aneurysms, secular aneurysms and intracranial stenosis correspond to one of the leading causes of stroke worldwide. All these diseases pertain to narrowing of major intracranial arteries due to the build-up of an atherosclerotic plaque. For example, in intracranial aneurysm also known as brain aneurysm, a cerebrovascular disorder is caused due to weakness in the wall of a cerebral artery or vein which causes localized dilation or ballooning (bulging). The most detrimental stage of the aneurysm is reached when the balloon bursts (and/or ruptures) leading to a stroke, massive internal bleeding, etc.
[3] In order to treat wide-neck aneurysm, intracranial aneurysms, secular aneurysms or intracranial stenosis, a cerebral balloon angioplasty is performed. However, angioplasty is associated with significant risks of intimal dissection, thrombosis, recoiling and/or vessel rupture.
[4] Other treatment strategies to cure aneurysms include surgical clipping of an artery which feeds the aneurysm, coiling method, glue, mesh stents flow diversion, etc. However, these methods exhibit various limitations due to the size of the bulge (aneurysm) which requires various open brain surgical procedures for treatment. For example, when the size of the bulge is smaller and the neck of the bulge is narrow, coils are placed with the help of microcatheters for their treatment. The use of said coils for the treatment of such aneurysms also exhibits various limitations. The said limitations include for example, slippage of the coil from the neck of the aneurysm into the artery thereby, blocking intracranial arteries or coil protrusion into the parent artery and subsequent thrombus formation thereby compromising the parent vessel.
[5] Yet other techniques to treat coil wide-neck aneurysms include flow diversion using stents. In this procedure, stents are implanted inside the intracranial blood vessels to treat the aforesaid conditions. However, the currently existing stent implant designs have complications while bending over torturous regions of the vessels and kink after deployment. The conventional stents mostly include open-cell structures which do not allow re-sheathing of the stent, if required and hence, such stents cannot be re-positioned once partially deployed. Further, the open-cell structures tend to extend outwards at bend locations thereby, increasing the chances of penetration of aneurysm.
[6] Thus, there arises a need for an implant that overcomes the problems associated with the conventional implants.
SUMMARY OF INVENTION
[7] 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 mere examples of the disclosure, which may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid populating 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.
[8] The present disclosure relates to an implant. The implant includes a tubular body having a proximal end and a distal end. The implant includes plurality of circumferential first rows of connecting elements having dense configuration and second row of connecting elements having sparse configuration. The two adjacent circumferential rows of connecting elements of the first row and second rows are connected with a plurality of links. The number of connecting elements in the first row are at least double the number of connecting elements of the connecting elements of the second row. The connecting elements of the two adjacent circumferential rows between two consecutive links form a closed cell structure.
BRIEF DESCRIPTION OF DRAWINGS
[9] The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the apportioned drawings. For the purpose of illustrating 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.
[10] Fig. 1 depicts an implant 100, according to an embodiment of the present disclosure.
[11] Fig. 2A depicts a flat cross-sectional view of the implant 100, according to an embodiment of the present disclosure.
[12] Fig. 2B depicts an inset view of the implant 100, according to an embodiment of the present disclosure.
[13] Fig. 2C depicts a detailed view of the proximal end 100a of the implant 100, according to an embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE DRAWINGS
[14] Prior to describing the invention 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.
[15] 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.
[16] 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.
[17] 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.
[18] The present disclosure relates to an implant. In an embodiment, the implant is an intracranial stent. The implant may be used to treat medical conditions such as, a wide neck aneurysm, a secular aneurysm, an intracranial aneurysm or an intracranial vessel having a deposition plaque. The implant may be further mounted over a delivery device for delivery of the implant inside the body. However, the teachings of the present disclosure may also be extended to implants used for other implantation sites such as peripheral vessels, carotid, renal blood vessels, etc.
[19] The implant of the present disclosure is made of plurality of closed cells formed by a plurality of rows of connecting elements, that provide effective placement of the implant inside the intracranial vessels. In an embodiment, the plurality of rows includes a first row and a second row of connecting elements that alternate with each other. In an embodiment, the first row and the second row may be connected via a plurality of links. The closed cell structures formed by the links and connecting elements allow re-sheathing of the stent, if required and hence, the stents of the present disclosure can be re-positioned once partially deployed. Further, the links function to enhance the flexibility and crimped profile along with effective radial properties to the implant. Due to this structure, the implants can easily bend over torturous regions of the vessels and provide less kinking after deployment.
[20] The implant of the present disclosure is designed to provide support to the coil mass within the aneurysm and minimize implant deflection. The implant is suitable to be used to treat wide- neck aneurysm having a diameter greater than or equal to 2mm and less than or equal to 4.5 mm. The implant can be easily loaded on to a delivery system due to the arrangement and structure of the first rows and second rows and link connections there between.
[21] Fig. 1 depicts an implant 100, according to the present disclosure. The implant 100 includes a tubular body having a proximal end 100a and a distal end 100b and a length extending there between. In an embodiment, the implant 100 has a flared proximal end 100a and a flared distal end 100b. Alternately, the diameter of the stent may be uniform from distal end to the proximal end. The tubular body includes a lumen that extends from the proximal end 100a to the distal end 100b. The tubular body may be radially expandable and collapsible. For instance, the tubular body of the implant 100 may expand once placed inside the body lumen. Further, for delivery of the implant 100, the tubular body may be radially collapsed over a catheter.
[22] The tubular body of the implant 100 is made of a plurality of rows of connecting elements (more clearly shown in Fig. 2A). The rows are disposed circumferentially such that one circumferential row of connecting elements sits on top of the previous circumferential row of connecting elements to form an implant 100 of required length. In an embodiment, the implant 100 includes two types of rows, a first row ‘X’ with densely populated connecting elements (referred as dense configuration) and a second row ‘Y’ with sparsely populated connecting elements (referred as sparse configuration). For example, the first row ‘X’ includes a greater number of connecting elements in comparison to the second row ‘Y’ due to the dense configuration while the second row ‘Y’ includes a smaller number of connecting elements in comparison to the first row ‘X’, due to the sparse configuration. For example, the ratio of connecting elements in the first row ‘X’ to the second row ‘Y’ is 2:1. Alternately, the ratio of connecting elements in the first row ‘X’ to the second row ‘Y’ may be more than 2:1. This arrangement of the first row “X” and the second row “Y” forms a close cell like structure which helps in expansion and loading of the stent in a delivery system and provides more flexibility compared to conventional stents.
[23] In the depicted embodiment, the first row ‘X’ and the second row ‘Y’ alternate with each other. Alternately, multiple first rows ‘X’ may be stacked one on top of the other followed by one or more second rows ‘Y’ stacked one on top of the other. Various other arrangements of the first row ‘X’ and the second row ‘Y’ are within the teachings of the present invention.
[24] In an embodiment, the proximal end 100a and the distal end 100b of the implant 100 may include the first row ‘X’ with a plurality of protrusions 104 that extend away from the tubular body as described in Fig. 2B below. These rows are referred as the proximal row and the distal row respectively. The first rows ‘X’ at the proximal end 100a and the distal end 100b provide higher radial strength to the stent implant.
[25] The connecting elements of the first row “X” and the second row “Y” may be arranged in a zig-zag or sinusoidal pattern defining a plurality of peaks “P”. Specifically, the point of contact of two adjacent or consecutive connecting elements is referred as the peak.
[26] In an embodiment, some of the peaks of a second row ‘Y’ are connected to the respective peaks of adjacent first rows ‘X’ via links 102 on either side. Similarly, except for the proximal and distal rows, some of the peaks of a first row ‘X’ are connected to the respective peaks of adjacent second rows ‘Y’ via links 102 on either side. The links 102 maybe straight connectors, S-shaped connectors, Z-shaped connectors, zig-zag connectors, etc. In an embodiment, the links 102 are provided at both the peaks of a connecting element of the second row ‘Y’ with one peak facing the proximal end 100a and the other consecutive peak facing the distal end 100b. In another embodiment, the links 102 are provided at first and fifth consecutive peaks of the first row ‘X’ with one peak facing the proximal end 100a and the other consecutive peak facing the distal end 100b.
[27] In an embodiment, the number of connecting elements in the first row “X” may be at least double the number of connecting elements in the second row “Y”. For example, between two consecutive links 102, eight connecting elements of the first row ‘X’ and four connecting elements of the second row ‘Y’ may be positioned. This assembly of the connecting elements of the first row ‘X’ and the second row ‘Y’ between two adjacent links 102 form a closed cell structure. The closed cells reduce the kinking of the implant 100 and also reduce the delivery profile of the implant 100 needed for efficient loading. It is to be noted that the number of connecting elements of the first row ‘X’ and the second row ‘Y’ between two adjacent links 102 may be more or less and depends upon the diameter of the stent.
[28] In an embodiment, every fifth peak of the first row ‘X’ coincides with every second peak of the second row ‘Y’ on one or both sides of the first row ‘X’.
[29] The dimensions of the connecting elements of the first and second row and links 102 are described via Fig. 2B. The length of a connecting element of the first row ’X’ is depicted as ‘L’. The length “L” may range between 1 mm to 2 mm. In an embodiment, the length “L” of the connecting element is 1.55 mm. The length of a connecting element of the second row ’Y’ is depicted as ‘G’. The length “G” may range between 1.5 mm to 2.5 mm. In an embodiment, the length “G” of the connecting element is 2.04 mm. It is to be noted that the length of the connecting elements of the first row and second row may be same or different.
[30] The height of the first row ‘X’ is depicted as “O” in expanded state. The height “O” may range between 1 mm to 2 mm. In an embodiment, the height “O” of the first row ‘X’ is 1.46 mm.
[31] The height of the second row ‘Y’ is depicted as “A” in expanded state. The height “A” may range between 1.5 mm to 2.5 mm. In an embodiment, the height “A” of the second row ‘Y’ is 1.75 mm.
[32] Two consecutive connecting elements of the first row may have an inner radius “R” and an outer radius “S”. The inner radius “R” may range from 0.01 mm to 0.08 mm and the outer radius “S” may range from 0.08 mm to 0.5 mm. In an embodiment, the inner radius is 0.05 mm and the outer radius is 0.2 mm.
[33] Two consecutive connecting elements of the first row ‘X’ may make a pre- defined angle “I” with each other in the expanded state. The angle “I” may range from 26o to 30o. In an embodiment, the angle is 28°.
[34] Two consecutive connecting elements of the second row ‘Y’ may have an inner radius D” and an outer radius “E”. The inner radius “D” may range from 0.08 mm to 0.3 mm and the outer radius “E” may range from 0.20 mm to 0.30 mm. In an embodiment, the inner radius is 0.1 mm and the outer radius is 0.25 mm.
[35] Two consecutive connecting elements of the second row ‘Y’ may make a pre- defined angle “B” with each other in the expanded state. The angle “B” may range from 50o to 60o. In an embodiment, the angle is 55°.
[36] The link 102 may have a length “K” ranging from 0.20 mm to 0.30 mm. In an embodiment, the length “K” of the link 102 is 0.25 mm. The link 102 may have a pre- defined width “N” ranging from 0.1 mm to 0.3 mm. In an embodiment, the width of the link 102 is 0.2 mm.
[37] At each peak, in the expanded state, a connecting element of first row ‘X’ may make a predefined angle ‘F’ with the adjacent connecting element of the second row ‘Y’. The angle “F” may range from 135° to 141°. In an embodiment, the predefined angle is 138°.
[38] The distance between two consecutive links 102 may be denoted as “M” and range from 2.5 mm to 5.5 mm. In an embodiment, the distance “M” is 3.99 mm.
[39] The peak-to-peak distance of one closed cell may be denoted as “J” and range from 3 mm to 4 mm. In an embodiment, the distance “J” is 3.46 mm.
[40] The implant 100 may have a uniform diameter from the proximal end 100a to the distal end 100b. The implant 100 may have a diameter ranging from 3 mm to 4.5 mm. In an embodiment, the implant 100 has a diameter of 3 mm, 4 mm and 4.5 mm. In an alternate embodiment, the implant 100 may have a tapered configuration from the proximal end 100a to the distal end 100b. The diameter of the implant 100 may also vary depending upon the vessel size of an individual.
[41] The implant 100 may be made of self-expanding materials such as without limitation Cobalt Chromium, Stainless Steel, Nitinol (Nickel-Titanium), platinum and tantalum. In an embodiment, the implant 100 is made of Nitinol (Nickel-Titanium) alloys.
[42] Fig. 2C depicts the expanded view of the proximal end 100a of the implant 100. As shown, the proximal end 100a commences with a first row of connecting elements ‘X’ followed by the second row of connecting elements ‘Y’. The proximal row includes connecting elements as in the first row ‘X’. Some of the peaks of the proximal row may be provided with one or more protrusions 104 extending away from the tubular body of the implant 100. The protrusions 104 may be extend parallel to the longitudinal axis of the implant 100 or may form an angle with respect to the longitudinal axis.
[43] In an embodiment, the protrusions 104 may extend from every fifth peak of the proximal row. The protrusions 104 may have a pre- defined length “P” and width “Q” ranging from 0.6 mm to 1 mm and 130 µm to 170 µm respectively. In an embodiment, the protrusions 104 have a length and width of 0.8 mm and 150µm. The protrusions 104 may have a pre- defined radius ranging from 0.07 mm to 0.09 mm. In an embodiment, the protrusions 104 have a radius of 0.08 mm. The protrusions 104 help to provide an efficient deployment of the implant 100 inside the blood vessels and also prevent the implant 100 from migrating.
[44] Similar to the proximal end 100a, protrusions 104 can be provided with the distal row. The features of the protrusions 104 at the distal row maybe the same as the protrusions 104 of the proximal row.
[45] On the other side of the connecting elements of the proximal row, the links 102 connect the proximal row to the second row ‘Y’. Similarly, at the distal end 100b, on the other side of the connecting elements of the distal row, the links 102 connect the distal row to the second row ‘Y’.
[46] The aforesaid implant 100 may be manufactured via methods known in the art. For example, the implant 100 may be manufactured by laser cutting a tube made of self-expanding material.
[47] 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 implant (100) comprising:
a) a tubular body having a proximal end (100a) and a distal end (100b);
b) a plurality of circumferential first rows “X” of connecting elements having dense configuration of the connecting elements;
c) a plurality of circumferential second rows “Y” of connecting elements having sparse configuration of the connecting elements; and
d) a plurality of links (102) connecting two adjacent circumferential rows of connecting elements, the adjacent circumferential rows including the first row “X” and the second row “Y”;
wherein number of connecting elements in the first row “X” are at least double the number of connecting elements in the second row “Y”; and
wherein the two consecutive links (102) and the connecting elements of two adjacent circumferential rows between two consecutive links (102) form a closed cell structure.
2. The implant (100) as claimed in claim 1, wherein ratio of the connecting elements in the first row ‘X’ to the connecting elements in the second row ‘Y’ is 2:1.
3. The implant (100) as claimed in claim 1, wherein the first row ‘X’ and the second row ‘Y’ are arranged alternately.
4. The implant (100) as claimed in claim 1, wherein a plurality of protrusions (104) is provided on the first row “X” at the proximal end (100a) and the distal end (100b) of the implant 100.
5. The implant (100) claimed in claim 4, wherein the protrusions 104 extend from every fifth peak of the proximal row.
6. The implant (100) as claimed in claim 4, wherein the plurality of protrusions 104 are one of parallel or angled with respect to the longitudinal axis of the implant 100.
7. The implant (100) as claimed in claim 1, wherein the connecting elements of the first row “X” and the second row “Y” are arranged in a zig-zag or sinusoidal pattern to define a plurality of peaks “P”.
8. The implant (100) as claimed in claim 1, wherein the links 102 are provided at first and fifth consecutive peaks of the first row ‘X’ with one peak facing the proximal end 100a and the other consecutive peak facing the distal end 100b.
9. The implant (100) as claimed in claim 1, wherein the closed cell structure includes two consecutive links 102, eight connecting elements of the first row ‘X’ and four connecting elements of the second row ‘Y’.
10. The implant (100) as claimed in claim 1, wherein the links (102) include one or more of straight connectors, S-shaped connectors, Z-shaped connectors, Zig-zag connectors.
11. The implant (100) as claimed in claim 1, wherein every fifth peak of the first row ‘X’ coincides with every second peak of the second row ‘Y’.