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:
VASCULAR FILTER
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
[001] The present disclosure relates to a medical device. More particularly, the present disclosure relates to a vascular filter.
BACKGROUND
[002] Inferior vena cava (IVC) is responsible to move blood from the lower body to the heart. Thereafter, this blood is pumped by the heart to the lungs to get oxygenated.
[003] Vena cava filters are one of the treatment options available to prevent pulmonary embolism for patients having thromboembolism, absolute contraindication to anticoagulation, etc. They also provide distal protection during vascular procedures.
[004] A vena cava filter is implanted within the IVC to capture any blood clots or pieces of thrombosis before they reach the lungs, thus preventing embolism.
[005] Conventionally available vena cava filters used for long-term implantation have a risk of migration/dislodgement, usually due to high blood pressure and/or heavy/big clot load. The said vena cava filter fails to hold/fixate the vena cava filter resulting in migration of the vena cava filter from its position.
[006] Further, the conventional vena cava filters are generally difficult to retrieve after their implantation.
[007] Hence, there arises a need of a filter which overcomes the problems related to conventional filters.
SUMMARY
[008] 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 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.
[009] The present disclosure relates to a filter including an elongate member, a plurality of first struts, a plurality of second struts and at least one V-shaped struts. The elongate member is disposed at a proximal end of the filter. The plurality of first struts extends away from the elongate member and towards a distal end of the filter. The plurality of first struts are radially collapsible and expandable. The plurality of second struts extends away from the elongate member and towards the distal end of the filter. The plurality of second struts are radially collapsible and expandable. The plurality of first struts are relatively smaller in length than the plurality of the second struts. The plurality of first struts and the plurality of second struts are arranged alternatingly. The at least one V-shaped struts coupling at least one of the first struts to an adjacently disposed one of the second struts.
BRIEF DESCRIPTION OF DRAWINGS
[0010] 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.
[0011] Fig. 1 depicts a filter 100 according to an embodiment of the present disclosure.
[0012] Fig. 1a depicts a cross-sectional view of a jacket 101b of the filter 100 according to an embodiment of the present disclosure.
[0013] Fig. 1b depicts a proximal view of the filter 100 according to an embodiment of the present disclosure.
[0014] Fig. 2 depicts a method to deploy the filter 100 according to an embodiment of the present disclosure.
[0015] Fig. 3 depicts a method to retrieve the filter 100 according to an embodiment of the present disclosure.
[0016] Fig. 3a depicts a retrieval sheath 10 to retrieve the filter 100 according to an embodiment of the present disclosure.
[0017] Fig. 3b depicts the filter 100 constrained within the retrieval sheath 10 according to an embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE DRAWINGS
[0018] 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.
[0019] 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.
[0020] 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.
[0021] 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.
[0022] The present invention discloses a vascular filter (or filter) used to filter blood flow and trap blood clots (or thrombus or emboli). The filter is used for various therapeutic purposes, such as thrombus capture in vena cava, distal protection during vascular procedures, etc. The filter is implanted inside a blood vessel of the patient, for example, with the patient’s inferior vena cava.
[0023] The filter of the present disclosure is provided with a plurality of struts having a plurality of barbs and a hook. The filter may be temporarily implanted within the vasculature tissue and then easily retrieved from therein, even after long term implantation. The filter is also suitable for permanent implantation at the discretion of the physician.
[0024] The clots in the blood stream are trapped inside the filter until the body’s own lytic system dissolves it into smaller fragments. The filter can also be used during implantation of other medical devices/implants or at the time of surgeries thereby preventing the risk of clots entering the heart.
[0025] The filter of the present disclosure is self-expandable from a radially collapsed state to a radially expandable state. The filter allows the physician to deploy the filter in an easy and controlled manner.
[0026] Now referring to the figures, Fig. 1 depicts an exemplary filter 100, according to an embodiment of the present disclosure. The filter 100 has a proximal end 100a and a distal end 100b. The filter 100 includes an elongate member 101, a plurality of first struts 103, a plurality of second struts 105 and a plurality of V-shaped struts 107. At least a portion of the filter 100 is self-expandable, for example, the plurality of first struts 103, the plurality of second struts 105, and the plurality of V-shaped struts 107 are radially collapsible and expandable.
[0027] The filter 100 is manufactured by cutting the filter 100 from a tube, i.e., the filter 100 includes an integrated structure. The tube may be made of a shape memory material including, but not limited to, nitinol, magnesium alloy, biocompatible polymers, etc. The tube may be cut using a pre-defined technique such as, but not limited to, wire electrical discharge machining (WEDM), laser cutting, micro abrasive waterjet cutting, etc. In an embodiment, the filter 100 is laser cut from a single piece of nitinol tube. The filter 100 may have a pre-defined shape such as, but not limited to, lunate, brolly, hastate, rhomboid etc. In an embodiment, as shown in Fig. 1, the filter 100 is brolly (or umbrella-like) shaped.
[0028] Although the filter 100 of the present disclosure is described with an example of an integrated structure, the filter 100 may have components either removably or fixedly coupled to each other and the same is within the scope of the teachings of the present disclosure.
[0029] The elongate member 101 is disposed at the proximal end 100a of the filter 100. The elongate member 101 may have pre-defined shape including, but not limited to, star shaped, tubular shaped, delta shaped, oval shaped, etc. The elongate member 101 may be solid or hollow. In an embodiment, the elongate member 101 has a hollow tubular shape. The elongate member 101 may have a pre-defined diameter ranging from 0.9 mm to 2.2 mm. In an embodiment, the diameter of the elongate member 101 is 1.8 mm.
[0030] At least a portion of the elongate member 101 is flared outwardly as a plurality of wings 101a. In an exemplary embodiment, as shown in Fig. 1, the elongate member 101 is provided with two outwardly flaring wings 101a. The wings 101a may be coupled to the elongate member 101 towards the proximal end 100a of the filter 100. The wings 101a may form a first angle with an axially extending axis (not shown) of the filter 100. The first angle ranges from 190° to 320°. In an embodiment, the first angle is 225°. The wings 101a help to easily grab (or snare) the filter 100 for easy retrieval from within the vasculature tissue (explained later). Due to the presence of more than one wings 101a, the filter 100 can be securely grabbed from one of the wings 101a if the other wing(s) 101a is compromised due to tilting of the filter 100.
[0031] The elongate member 101 is provided with a jacket 101b (as shown in Fig. 1a). The jacket 101b is disposed within the elongate member 101 towards the proximal end 100a of the filter 100. The jacket 101b is provided with a plurality of internal threads 101b1 configured to receive a delivery wire (not shown). The internal threads 101b1 are used to screw the delivery wire to the elongate member 101 (explained later).
[0032] The first struts 103 extend away from the elongate member 101 and towards the distal end 100b of the filter 100. In an exemplary embodiment, as shown in Fig. 1, the filter 100 is provided with three first struts 103. The first struts 103 may have a pre-defined shape including, but not limited to, ramp shaped, straight shaped, sine shaped, zig-zag shaped, etc. In an embodiment, as shown in Fig. 1, the first struts 103 have a slight sine shape. The first struts 103 may have a pre-defined length ranging from 20 mm to 50 mm. The first struts 103 may have a pre-defined width ranging from 0.2 mm to 1.0 mm. The first struts 103 may have a pre-defined thickness ranging from 0.1 mm to 0.4 mm. In an exemplary embodiment, the length, width, and thickness of the first struts 103 are 40 mm, 0.4 mm, and 0.2 mm, respectively. The first struts 103 provide stability to the filter 100 by preventing the filter 100 from tilting. The first struts 103 provide strength to the filter 100 and help to entrap the blood clots.
[0033] Each of the first struts 103 may be provided with at least one first barb 103a. The first barbs 103a may be disposed towards the distal end 100b of the filter 100. The first barbs 103a may have any pre-defined shape including, but not limited to, hook shaped, L-shaped, V-shaped, N-shaped, etc. In an embodiment, as shown in Fig. 1, each of the first struts 103 is provided with one V-shaped first barb 103a.
[0034] The second struts 105 extends away from the elongate member 101 and towards the distal end 100b of the filter 100. In an exemplary embodiment, the filter 100 is provided with three second struts 105. The second struts 105 may have a pre-defined shape including, but not limited to, J-shaped, flare shaped, Arabic six shaped (?), sine shaped, waning crescent shaped, etc. In an embodiment, as shown in Fig. 1, the second struts 105 have a slight sine shape. The second struts 105 may have a pre-defined length ranging from 38 mm to 58 mm. The second struts 105 may have a pre-defined width ranging from 0.2 mm to 1.2 mm. The second struts 105 may have a pre-defined thickness ranging from 0.1 mm to 0.4 mm. In an exemplary embodiment, the length, width and thickness of the second struts 105 are 46 mm, 0.6 mm and 0.2 mm, respectively. The second struts 105 provide strength and stability to the filter 100 to grasp the surrounding wall of the blood vessel after the filter 100 is deployed. The second struts 105 help in uniform deployment of the filter 100 and help to entrap the blood clots.
[0035] Each of the second struts 105 may be provided with at least one second barb 105a. The second barbs 105a may be disposed towards the distal end 100b of the filter 100. The plurality of second barbs 107’ may have a pre-defined shape including, but not limited to, Latin gamma shaped (?), r-shaped, J-shaped, square root shaped (v), psi shaped (?), etc. In an embodiment, as shown in Fig. 1, each of the second struts 105 is provided with a J-shaped second barb 105a.
[0036] The first and second barbs 103a, 105a help to hold and secure the filter 100 within the vasculature after the filter 100 is deployed, i.e., once the filter 100 is deployed within a blood vessel the first and second barbs 103a, 105a provide resistance to migration and tilting of the filter 100. The first and second barbs 103a, 105a also prevent transverse rotation of the filter 100 within the blood vessel. The pre-defined shape of the first and second barbs 103a, 105a minimizes the risk of puncture and trauma to the blood vessels and provides good holding ability to the filter 100 in severe circumstances such as high blood pressure.
[0037] The first struts 103 and the second struts 105 may have different lengths. In an exemplary embodiment, as shown in Fig, 1, the first struts 103 have a relatively smaller length than the second struts 105. The difference in length of the first and second struts 103, 105 provides easy and controlled expansion of the filter 100 while the filter 100 is being deployed within the blood vessel (explained later).
[0038] As shown in Figs. 1 and 1b, the first struts 103 and the second struts 105 are arranged alternatingly in a circular manner such that at least one of the first struts 103 is coupled to an adjacently disposed one of the second struts 105 via at least one V-shaped strut 107. In an exemplary embodiment, as shown in Fig. 1, the filter 100 is provided with three first struts 103 and three second struts 105 arranged alternatively such that each first strut 103 is coupled to the adjacently disposed second strut 105 via one V-shaped strut 107.
[0039] The V-shaped struts 107 may be disposed between the adjacent first and second struts 103,105. The V-shaped struts 107 may point towards the proximal end 100a or the distal end 100b of the filter 100. In an exemplary embodiment, as shown in Fig. 1, the V-shaped struts 107, pointing towards the distal end 100b, are disposed adjacent to the elongate member 101. The V-shaped struts 107 along with the first and the second struts 103, 105 help to form a mesh-like structure (as shown in Fig. 1b) of the filter 100. The mesh-like structure of the filter 100 helps to filter the blood flow and entraps blood clots.
[0040] Fig. 2 depicts an exemplary method 200 to deploy the filter 100 within a vasculature. The method 200 commences at step 201 by radially collapsing the first and second struts 103, 105 and constraining the filter 100 within a delivery sheath (not shown). The delivery sheath prevents the filter 100 from radially expanding such that the filter 100 can be safely advanced to an implantation site within the vasculature.
[0041] At step 203, the delivery wire is coupled to the filter 100. In an exemplary embodiment, an end of the delivery wire (not shown) is screwed to the internal threads 101b1 of the jacket 101b.
[0042] At step 205, the filter 100 is advanced to and positioned at the implantation site within the vasculature.
[0043] At step 207, the filter 100 is gradually pushed out of the delivery sheath thereby enabling the filter 100 to gradually self-expand. In an exemplary embodiment, the filter 100 is pushed out of the delivery sheath by pushing the delivery wire while the delivery sheath is kept stationary. In another embodiment, the filter 100 is pushed out of the delivery sheath by retracting the delivery sheath while the delivery wire is kept stationary. In yet another embodiment, the filter 100 is gradually pushed out of the delivery sheath by simultaneously retracting the delivery sheath and pushing the delivery wire.
[0044] Due to the difference in length of the first and second struts 103, 105, while the filter 100 is gradually pushed out from the delivery sheath, the filter 100 is deployed in a controller and step-wise manner.
[0045] At step 207a, the second struts 105 self-expand prior to the first struts 103. Accordingly, the second struts 105 grasp the surrounding wall of the vasculature before the first struts 103.
[0046] After step 207a, the physician may optionally reposition the filter 100 within the vasculature.
[0047] At step 207b, the first struts 103 self-expand after the second struts 105 has grasped the surrounding wall of the vasculature.
[0048] At step 207c, the delivery sheath is completely retracted from over the filter 100 before the first struts 103 are able to grasp the surrounding wall of the vasculature. The complete retraction of the delivery sheath from over the filter 100 induces a sudden jolt in the filter 100. Since the second struts 105 have already grasped the surrounding wall of the vasculature, the sudden jolt is safely absorbed within the vasculature without the filter 100 getting disoriented at the implantation site.
[0049] At step 207d, the first struts 103 grasps the surrounding the wall of the vasculature thereby securing the filter 100 at the implantation site.
[0050] At step 209, the delivery wire is unscrewed from the internal threads 101b1 of the jacket 101b.
[0051] At step 211, the delivery wire along with the delivery sheath is withdrawn from the implantation site.
[0052] Fig. 3 depicts an exemplary method 300 to retrieve the filter 100 after the filter 100 has been deployed at the implantation site. The method 300 commences at step 301 by determining the location of the deployed filter 100 within the vasculature. In an exemplary embodiment, the location of the filter 100 is confirmed by X-ray imaging with contrast.
[0053] At step 303, a retrieval sheath 10 (as shown in Fig. 3a) along with a snare loop 11 (as shown in Fig. 3a) is advanced to the location of the deployed filter 100 within the vasculature. The snare loop 11 includes a retrieval wire with one or more loops 11a at an end. The snare loop 11 is disposed within a lumen of the retrieval sheath 10.
[0054] At step 305, the snare loop 11 is advanced out of the retrieval sheath 10 such that at least one loop 11a of the one or more loops 11a of the snare loop 11 encircles at least one of the wings 101a of the filter 100 (as shown in Fig. 3a).
[0055] At step 307, the snare loop 11 is retracted within the retrieval sheath 10 to snag the loop(s) 11a of the snare loop 11 with the wing(s) 101a of the filter 100.
[0056] At step 309, the retrieval sheath 10 is gradually advanced to constrain the filter 100 within the lumen of the retrieval sheath 10 (as shown in Fig. 3b). While the retrieval sheath 10 is gradually advanced over the filter 100, the filter 100 radially collapses.
[0057] At step 311, the retrieval sheath 10 constraining the filter 100 is withdrawn from within the vasculature.
[0058] 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. A filter (100) comprising:
a. a proximal end (100a) and a distal end (100b);
b. an elongate member (101) disposed at the proximal end (100a);
c. a plurality of first struts (103) extending away from the elongate member (101) and towards the distal end (100b), the plurality of first struts (103) being radially collapsible and expandable;
d. a plurality of second struts (105) extending away from the elongate member (101) and towards the distal end (100b), the plurality of second struts (105) being radially collapsible and expandable, the plurality of first struts (103) being relatively smaller in length than the plurality of the second struts (105), the plurality of first struts (103) and the plurality of second struts (105) arranged alternatingly; and
e. at least one V-shaped struts (107) coupling at least one of the first struts (103) to an adjacently disposed one of the second struts (105).
2. The filter (100) as claimed in claim 1, wherein at least a portion of the elongate member (101) flare outwardly as a plurality of wings (101a).
3. The filter (100) as claimed in claim 1, wherein a jacket (101b) is provided within the elongate member (101).
4. The filter (100) as claimed in claim 3, wherein the jacket (101b) is provided with a plurality of internal threads (101b1) configured to receive a delivery wire.
5. The filter (100) as claimed in claim 1, wherein each of the plurality of first struts (103) are provided with at least one first barb (103a).
6. The filter (100) as claimed in claim 5, wherein the first barbs (103a) are one of L-shaped, V-shaped, or N-shaped.
7. The filter (100) as claimed in claim 1, wherein each of the plurality of the second struts (105) are provided with at least one second barb (105a).
8. The filter (100) as claimed in claim 7, wherein the second barbs (105a) are one of Latin gamma shaped (?), r-shaped, J-shaped, square root shaped (v), or psi shaped (?).
9. The filter (100) as claimed in claim 1, wherein the first struts (103) are one of ramp shaped, straight shaped, sine shaped, or zig-zag shaped.
10. The filter (100) as claimed in claim 1, wherein the second struts (105) are one of J-shaped, flare shaped, Arabic six shaped (?), sine shaped, or waning crescent shaped.