Claims:WE CLAIM:
1. An embolic protection system (10’) comprising:
a delivery system (20) having a distal end, the delivery system (20) including an implantable medical device (100) at the distal end; and
an embolic protection device (10) provided towards the distal end of the delivery system (20), the embolic protection device (10) further comprising:
a frame (12) having a proximal end (10a) and a distal end (10b), the frame (12) including a proximal section (12a) disposed at its proximal end (10a) and a distal section (12b) disposed adjacent to the proximal section (12a), the proximal section (12a) including at least one row of cells arranged circumferentially, the distal section (12b) including a plurality of arms(b1) placed circumferentially and extending in the axial direction, each arm (b1) of the plurality of arms (b1) including a plurality of holes (b2) and being connected to an adjacently placed arm (b1) via a plurality of links (b3); and
a mesh (14) being secured to the frame (12) via the plurality of holes (b2) for blood filtration and capturing of one or more embolic particles,
wherein each of the plurality of links (b3) include a pre-defined shape having a pre-defined angle which prevents overlapping of the arms (b1) to allow uniform crimping and low crimp profile of an embolic protection device (10),
wherein each arm (b1) is curved inwardly towards the distal end (10b) to minimize damage to an arterial wall.
2. The embolic protection system(10’) as claimed in claim 1, wherein the implantable medical device (100) includes one or more of a prosthetic heart valve, a clot retrieval device, an aortic stent graft, a vena cava filter or other heart related devices.
3. The embolic protection system(10’) as claimed in claim 1, wherein the frame (12) is made from one or more biocompatible metals selected from stainless steel, cobalt chromium alloy, nickel titanium alloy (nitinol) or platinum and tantalum alloys.
4. The embolic protection system (10’) as claimed in claim 1, wherein the at least one row of cells include two rows of rhombus shaped closed cells.
5. The embolic protection system (10’) as claimed in claim 1, wherein the plurality of arms (b1) include six arms.
6. The embolic protection system(10’) as claimed in claim 1, wherein the pre-defined shape includes one of a V-shape, an elliptical shape, a zig-zag shape, a U-shape, a W-shape or an inverted V-shape.
7. The embolic protection system (10’) as claimed in claim 1, wherein the plurality of holes (b2) are disposed in pairs.
8. The embolic protection system (10’) as claimed in claim 1, wherein the mesh (14) includes a fabric mesh made from one of nylon, polytetrafluoroethylene (PTFE), polypropylene or polyethylene.
9. The embolic protection system (10’) as claimed in claim 1, wherein the mesh (14) includes a pore size ranging from 40µm to 140µm.
10. The embolic protection system (10’) as claimed in claim 1, wherein the mesh (14) includes a thickness ranging from 50µm to 100µm. , 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:
EMBOLIC PROTECTION SYSTEM
2. APPLICANTS:
Meril Life Sciences Pvt. Ltd, an Indian Company, of the address Survey No. 135/139, Bilakhia House Muktanand Marg, Chala, Vapi- 396191, Gujarat, India

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

FIELD OF INVENTION
[001] The present invention relates to a medical device, more specifically, the present invention corresponds to an embolic protection system.
BACKGROUND
[002] A human heart has four valves namely a mitral valve, a tricuspid valve, an aortic valve and a pulmonary valve. Out of them, the aortic valve is situated in the lower left heart chamber and controls the blood flow from the heart to the aorta and further towards the rest of body. However, as the age progresses, accumulation of calcium particles on the aortic valve leaflets increases which further restricts opening of valve leaflets. Such a condition is known as aortic stenosis. People with severe aortic stenosis have symptoms like shortening of breath, chest pain, heart murmur, etc. Therefore, there is need to replace the stenosed heart valve.
[003] Stenosed heart valve can be replaced either by a surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement process (TAVR). Currently, transcatheter aortic valve replacement (TAVR) is recognized as the most beneficial method for the patients having high surgical risk for replacing stenosed heart valve owing to the fact that it is a minimally invasive procedure.
[004] During TAVR process, a native damaged heart valve is replaced with the new functional prosthetic heart valve. However, during this process, calcified debris and other embolic particles are released from the stenosed heart valve. Such embolic particles pass through bloodstream and may block the sub-arteries of aortic arch (like carotid) leading to a stroke or transient ischaemic attack. Further, aorta has three sub arteries which supply oxygenated blood to the brain, muscles and other body parts. Hence, if calcium and other embolic particles reach brain with blood flow, they may create brain embolization and lesions in cerebral blood vessel which may in turn create blockage in the vessel. Blockage of the vessels may gradually lead to sudden stroke i.e. a “silent stroke”. Therefore, cerebral embolic protection devices are recommended to prevent the migration of these calcified particles to prevent the aforesaid conditions.
[005] The conventional embolic protection devices however, have associated drawbacks which build up a need for a more superior and advanced device. For instance, the currently available devices are so structured that the struts of the devices are unable to withstand the pressure exerted by arteries and easily break and/or deform. Also, the struts of the embolic devices have sharp ends which cause damage to the vessel walls. Further, owing to the limitation of the structures of existing embolic protection devices, the devices include a crimp profile which require large sized delivery sheaths and/or two punctures. The use of such delivery sheaths ultimately leads to making larger puncture for insertion of embolic protection device with TAVR delivery system and hence may make operational procedure more challenging.
[006] Therefore, there exists a need of an improved embolic protection device with TAVR delivery system which overcomes the drawbacks of existing systems.
SUMMARY
[007] The present invention discloses an embolic protection system having a delivery system including an implantable medical device and an embolic protection device. The embolic protection device includes a frame having a proximal end and a distal end. The frame further includes a proximal section disposed at its proximal end and a distal section disposed adjacent to the proximal section. The proximal section further includes at least one row of cells arranged circumferentially. The distal section includes a plurality of arms that are placed circumferentially and extend in the axial direction. Each arm is curved inwardly towards the distal end to minimize damage to an arterial wall.
[008] Each arm of the plurality of arms has a plurality of holes and is connected to an adjacently placed arm via a plurality of links. Each of the plurality of links include a pre-defined shape having a pre-defined angle which prevent overlapping of the arms to allow uniform crimping and low crimp profile of an embolic protection device.
[009] The embolic protection device further includes a mesh being secured to the frame via the plurality of holes for blood filtration and for capturing of one or more embolic particles.
[0010] 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
[0011] 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 instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale.
[0012] FIG. 1 shows the embolic protection device 10 in deployed state in accordance with an embodiment of the present invention.
[0013] FIG. 1a depicts an embolic protection device 10 in accordance with an embodiment of the present invention.
[0014] FIG. 2 depicts a frame 12 in accordance with an embodiment of the present invention.
[0015] FIG. 2a depicts an exploded view of arm b1 at the second distal end 12b2 in accordance with an embodiment of the present invention.
[0016] FIG. 2b and 2c illustrate alternate embodiments of the frame 12 in accordance with an embodiment of the present invention.
[0017] FIG. 3 depicts the embolic protection device 10 is in compressed state in accordance with an embodiment of the present invention.
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] 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 and apparatus can be used in combination with other systems 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 corresponds to an embolic protection system. The embolic protection system includes an embolic protection device used with a delivery system. The delivery system of the present invention is a transcatheter delivery system. The embolic protection device of the present invention is used to capture one or more embolic particles that may be released during TAVR without hindering the normal blood flow. However, it should be noted that the embolic protection device may also be used for capturing embolic particles during implantation of other implantable medical devices such as clot retrieval devices, aortic stent graft, vena cava filter, other heart related device, etc.
[0023] The embolic protection system of the present invention is implanted through a single sheath through a single insertion.
[0024] The embolic protection device includes a self-expandable frame. The embolic protection device includes an expandable state and a compressed state. The expandable state of the embolic protection device refers to the deployed state of the embolic protection device. The compressed state of the embolic protection device corresponds to the state of the embolic protection device when disposed within a delivery sheath.
[0025] The frame includes a proximal section and a distal section. The proximal section includes a tubular structure having at least one row of closed cells. The proximal section offers easy crimping/welding of the embolic protection device on the delivery catheter.
[0026] The distal section extends from the proximal section towards a distal end of the embolic protection device. The distal section translates to a conical shaped structure in the expanded state. The distal section includes a plurality of arms having multiple holes. All the arms are uniformly distributed around the circumference of the distal section and shaped in such a way that the distal section of the frame remains in close contact with the wall of the aorta thereby offering strength to the embolic protection device to withstand blood flow. The arms may be slightly curved inwardly at the distal end to reduce arterial wall damage.
[0027] The aforesaid arms of the frame are connected to each other through angled links for example, “V / inverted V” shaped links. Such links prevent overlapping of the arms which might occur during compression of the embolic protection device thereby allowing uniform crimping of the embolic protection device to achieve a low crimp profile. Owing to the use of angled links, there is an approximate reduction of almost 50% in crimp profile as compared to the conventional systems. Furthermore, “V/ inverted V” shaped link assures full coverage of an aorta lumen during the expanded state which captures most embolic particles during the TAVR process.
[0028] The embolic protection device further includes a fabric mesh which is stitched over the inner surface of the frame via the holes. The fabric mesh is a porous mesh which captures the embolic particles from the blood which passes through it.
[0029] FIG. 1 shows the embolic protection system 10’ deployed at a deployment site. The embolic protection system 10’ includes an embolic protection device 10 and a delivery system 20. The embolic protection device 10 is deployed using a delivery system 20 at the deployment site. The deployment site in the present invention corresponds to aorta. However, the embolic protection device 10 can be deployed at other sites such as sinotubular junction and ascending aortaas per the teachings of the present invention. In an embodiment, the embolic protection device 10 is deployed before a brachiocephalic artery in ascending aorta/sinotubular junction. The deployment of the embolic protection system at such a position results in coverage of all the sub-arteries of the aorta thereby, completely eliminating any chance of a stroke or passing of embolic particle.
[0030] As shown in FIG. 1, the embolic protection device 10 is mounted towards a distal end of the delivery system 20 in expanded state. As shown in FIG. 1, a prosthetic heart valve 100 is also disposed at the distal end of the delivery system 20. Though the present invention is explained via a prosthetic heart valve, the delivery system 20 of the present invention may be used for deploying other implantable medical devices as well.
[0031] On expansion of the prosthetic heart valve 100, calcified debris and other embolic particles are released from a stenosed heart valve which is then captured by the embolic protection device 10.
[0032] In expanded state, the blood is filtered through the embolic protection device 10 as it captures the embolic particles. After the completion of TAVR process, the embolic protection device 10 having the captured embolic particles is enclosed within a delivery sheath20a and the embolic protection device 10 is withdrawn.
[0033] FIG. 1a depicts the embolic protection device 10 of the present invention in expanded state. As shown in FIG. 1a, the embolic protection device 10 includes a proximal end 10a and a distal end 10b.
[0034] The size of the embolic protection device 10 may vary depending upon the inner diameter of the ascending aorta. In an embodiment, the size of the embolic protection device 10 is selected from 25mm to 45mm at an interval of 5 mm depending on the diameter of prosthetic heart valve 100 from 18mm to 34mm.Owing to such selection of size, the embolic protection device 10 fits well in the ascending aorta and also maintains proper position during operation.
[0035] The total length of the embolic protection device 10 may range from 30mm to 60mm. In an embodiment, the embolic protection device 10 has a length of 45mm. The diameter of the embolic protection device 10 in expanded state may range from 10mm to 60mm. In an embodiment, the diameter of the embolic protection device 10 in expanded state is 35mm. The diameter of the embolic protection device 10 in compressed state may range from 2mm to 8mm. In an embodiment, the diameter of the embolic protection device 10 in compressed state is 4.5mm.
[0036] As shown in FIG. 1a, the embolic protection device 10 includes a frame 12 and a mesh 14.The mesh 14 is placed within the frame 12 and is secured to an inner surface of the frame 12 (described below).
[0037] The frame 12 of the present invention is a self-expandable structure. The frame 12 may be made of one or more biocompatible metals. The metals may include without limitation, stainless steel, cobalt chromium alloy, nickel titanium alloy (nitinol), platinum and tantalum alloys, etc. In an embodiment, the frame 12 is made from nitinol. Nitinol is utilized for the making the embolic protection device 10 due to its super elasticity and shape memory properties.
[0038] The frame 12 includes a pre-defined structure which may be formed via any conventional technique. In the present invention, the frame 12 is made from a nitinol tube via Nd:Yag laser cutting. The outer diameter of the nitinol tube may range from 1mm to 10mm and the thickness may range from 0.05mm to 1.0mm. Laser cutting may depend upon few crucial parameters such as without limitation, pulse energy, frequency, gas pressure and output power. In the present invention, pulse energy during the laser cutting process is maintained between from 50µJ to 65µJ. The frequency may range from 160KHz to 172KHz. Argon gas pressure may range from 10bar to 18bar. Power may range from 7Watt to 15Watt.
[0039] After the laser cutting process, shape setting of the frame 12 is performed using a mould. In an embodiment, the frame 12 is attached to a stainless steel (SS) mould and kept in the aluminum fluidized bath at specific temperature for specific time. For achieving the desired shape and to eliminate the chances of frame breakage, multiple different diameter moulds may be used. For example, three moulds of different diameters may be used - 15mm, 30mm and 45mm diameters. The diameter of the frame 12 after first moulding operation may range from 15mm to 30mm, after second moulding operation may range from 30mm to 35mm and after third moulding operation may range from 35mm to 45mm. The temperature of shape setting process may range from 475°C temperature to 520°C temperature and the shape setting process time may range from 2.5min to 8min. In an embodiment, the temperature and time are 502°C and 5minutesrespectively.
[0040] Thereafter, sand blasting or abrasive blasting is performed to obtain a smooth surface by forcibly propelling stream of abrasive material on a rough surface. In an embodiment, air driven sand blasting process is performed. Sand blasting process depends upon two parameters namely blast pressure and working time. The blast pressure may range from 1.1bar to 3.0bar. In an embodiment, the blast pressure is 2.0bar. The sandblasting time may range from 30seconds to 55seconds. In an embodiment, the time is 42seconds.
[0041] After the completion of the sand blasting process, electropolishing process is performed for reducing the roughness of surface by leveling the micro peak. In an embodiment, a mixture of acetic acid (78%) and perchloric acid (22%) is used as an electrolyte and stainless Steel (SS) plate is used as cathode. The temperature of electrolyte bath may ranges from 5°C temperature to 20°C temperature. In an embodiment, the temperature is 15°C. Further, current for electropolishing may range from 0.08A to 1.5Awhile the voltage may range from 6V to 15V. In an embodiment, the current and voltage are 0.7A and 10V respectively.
[0042] The frame 12 may include a proximal end which is same as the proximal end 10a of the embolic protection device 10 while a distal end of the frame 12 may be same as the distal end 10b of the embolic protection device 10. The frame 12 includes at least two portions i.e. a proximal section 12a and a distal section 12b as represented in FIG. 2. The proximal section 12a and the distal section 12b may form an integral structure or alternately, be two separate structures coupled together via a conventional technique. In an embodiment, the proximal section 12a and the distal section 12b form an integral structure of the embolic protection device 10.
[0043] The proximal section 12a may be disposed towards the proximal end 10a of the embolic protection device 10 while the distal section 12b is positioned at the distal end 10b of the embolic protection device 10.
[0044] The proximal section 12a may be a tubular structure having pre-defined dimensions. The proximal section 12a may include a pre-defined length and a pre-defined diameter. The length of the proximal section 12a may range from 5mm to 15mm. In an embodiment, the length of the proximal section 12a is 10mm. The diameter of proximal section 12a may be uniform or non-uniform along its length. In an exemplary embodiment shown in FIG. 1a, the diameter of the proximal section is uniform and may range from 3mm to 5mm. In an embodiment, the diameter of the proximal section is 4 mm.
[0045] The proximal section 12a may include at least one row of cells arranged circumferentially. The cells may be open or closed. The shape of the cells may be of any conventional shape such as, without limitation, hexagonal, square, rhombus, etc. In an embodiment, the proximal section 12a includes two rows of rhombus shaped closed cells. The number of rows of closed cells and the dimensions of the closed cells may be dependent upon the dimensions of the proximal section 12a which may in turn be dependent on the anatomy of the deployment site. The length of each closed cell may range from 2mm to 10mm. In an embodiment, the length of each closed cell is 5mm.
[0046] The aforesaid structure of the proximal section 12a of the embolic protection device 10 helps in crimping/welding of the embolic protection device 10 on the delivery system 20.
[0047] The distal section 12b of the frame 12 extends from the distal edge of the proximal section 12a towards the distal end 10b of the embolic protection device 10. As shown in FIG. 2, the distal section 12b translates to a conical shape in expanded state which helps to capture the embolic particles. However, other shapes of the distal section 12b are also within the scope of the present invention.
[0048] The distal section 12b includes a second proximal end 12b1 and a second distal end 12b2. The second proximal end 12b1 and the second distal end 12b2 have same diameter when the embolic protection device 10 is in compressed state. However, owing to the conical shape of the distal section 12b in expanded state, the diameter of the second distal end 12b2 becomes more than the diameter of the second proximal end 12b1.The diameter of the second proximal end 12b1 may range between 3mm and 6mm. In an embodiment, the diameter of the second proximal end 12b1 is 4mm. The diameter of the second distal end 12b2 may range between 25mm to 45mm. In an embodiment, the diameter of the second distal end 12b2 is 40mm.
[0049] The distal section 12b includes a plurality of arms b1 that are placed circumferentially and extend in an axial direction. In an embodiment, the distal section 12b includes six arms b1. The arms b1 may be spaced uniformly at a pre-defined distance or may have non-uniform distribution. In an embodiment, the arms b1 are distributed uniformly.
[0050] The dimensions of all the arms b1 may be same or different. In an embodiment, the dimensions of all the arms b1 are same. For example, the length of each arm b1 may range from 30mm to 40mm and the width of each arm b1 may range from 0.5mm to 1.0mm. In an embodiment, the length and the width of each arm b1 are 35mm and 0.8mmrespectively.
[0051] In an embodiment, the arms b1 are curved inwardly towards the second distal end 12b2 as shown in FIG. 2a. Such curved arms b1 minimize any risk of damage to the arterial wall. A portion of the arms b1 at the second distal end 12b2 may remain relatively straight. In an embodiment, around 10mm to 20mm of each arm b1 towards second distal end 12b2 remains relatively straight and in close contact with the lumen.
[0052] Each of the arms b1 may include a plurality of holes b2 for securing the mesh 14. The number of holes b2 may range from 10 to 15. The disposition of the holes b2 over the arms b1 may follow a pre-defined pattern. In an embodiment as shown in FIGs. 2-2c, the holes b2 are disposed in pairs. In an embodiment, each arm b1 includes a total of 12 holes placed as 6 pairs. The distance between each of the pairs may be same or different. In an embodiment, the distance between each pair of holes b2 is 6mm. The pairs of holes b2 are equally spaced so that the mesh 14 may be tightly stitched to the frame 12.
[0053] The diameter of each of the holes b2 may range between 0.45mm and 0.55mm. In an embodiment, the diameter of each hole b2 is 0.5mm. The aforesaid diameter and number of holes b2 help to provide sufficient strength for attachment of the mesh 14 of embolic protection device 10 to remain in position against blood flow in aorta and also prevent the escape of embolic particles.
[0054] The above described arms b1 of the distal section 12b may be connected with each other through a plurality of links b3. The number of links b3 may be same as the number of arms b1. The links b3 in the embolic protection device 10 may include a pre-defined shape. The pre-defined shape of the links b3 may be formed by connecting at least two struts at a pre-defined angle. Alternately, the links b3 may be include a single strut having bent at a pre-defined angle for example in shapes such as without limitation, V-shape (FIG. 2), elliptical (FIG. 2c), zig-zag, U-shape, W-shape, inverted V-shape (FIG. 2b), etc.
[0055] In an embodiment, the links b3 are “inverted V” shaped links as shown in FIG. 2b. The use of such links b3 provides stability and assure full coverage of the lumen of aorta thereby minimizing any chances of the embolic particles to escape. Moreover, during the compression of embolic protection device 10, such angled links b3 prevent overlapping of the arms b1 thereby allowing uniform crimping and low crimp profile. In an embodiment, there is approximately 50% reduction in crimp profile of the embolic protection device 10’ as compared to the conventional systems. Due to low profile of device 10, the size of outer as well as inner diameter of delivery sheath 20a also reduces which ultimately lead to the requirement of minor puncture for insertion into the human body.
[0056] The length of the “V shaped” links b3 may range from 20mm to 30mm. In an embodiment, the length of the “V shaped” links b3 is 25mm. The width of the “V shaped” links b3 may range from 0.2mm to 0.4mm. In an embodiment, the width of the “V shaped” links b3 is 0.3mm. The thickness of the “V shaped” links b3 may range from 0.08mm to 0.25mm. In an embodiment, the thickness of the “V shaped” links b3 is 0.15mm.
[0057] In an embodiment, the embolic protection device 10 includes a plurality of radiopaque markers for easy visibility and traceability of the embolic protection device 10. The number of radiopaque markers varies from 3 to 12. The markers may be disposed on a pre-defined location on the frame 12 (not shown).
[0058] The mesh 14 may be secured to the inner surface of the above described frame 12. The mesh 14 of the embolic protection device 10 is used for blood filtration and capturing embolic particles.
[0059] The mesh 14 may be knitted, braided or laser processed. The mesh 14 may be made from one or more polymers such as, but not limited to, nylon, polytetrafluoroethylene (PTFE), polypropylene, polyethylene, etc. In an embodiment, the mesh 14 is a fabric mesh made of nylon. The mesh 14 may be a micro-porous or a macro-porous mesh. In an embodiment, the mesh 14 is a micro-porous structure having a pre-defined pore size. The pore size may range from 40µm to 140µm. In an embodiment, the pore size of the mesh 14 is 80µm.
[0060] The thickness of the mesh 14 may range from 50µm to 100µm. In an embodiment, the thickness of the mesh 14 is 60µm. Owing to such thickness, the diameter of the embolic protection device 10 remains low which results in easier compression and delivery of embolic protection device 10 with the delivery system 20 through small introducer sheath.
[0061] The mesh 14 is stitched to the frame 12 via holes b2 with the help of a suture. The suture may be made from a braided material. The braided material may be non-resorbable in nature. The suture may be made from, without limitation, nylon, polyester, polyvinylidene fluoride (PVDF), polypropylene or their derivatives, etc. In present invention, a non-resorbable braided suture is used and material of suture is polyester. The use of braided suture provides high tensile strength, easy handling and secure knot tying.
[0062] The diameter of the suture may range from 25µm to 60µm. In an embodiment, the diameter of the suture is 35µm.
[0063] The above disclosed embolic protection device 10 is covered with the delivery sheath 20a in compressed state as shown in FIG. 3.The delivery sheath20a moves backward or forward to open or close the embolic protection device 10 respectively.
[0064] The delivery sheath 20a may be made of a biocompatible plastic having adequate flexibility and rigidity such as poly-tetrafluoro ethylene (PTFE), low-density polyethylene (LDPE), high-density polyethylene (HDPE), pebax, etc. In an embodiment of the present invention, a braided PTFE tube is used as the delivery sheath 20a. The braided tube may include three layers i.e. an inner PTFE layer, a middle SS braided layer and an outer pebax layer. The inner diameter of the delivery sheath 20a may range from 12Fr to 21Fr. In an embodiment, the inner diameter of the delivery sheath 20a is 14Fr. The outer diameter of the delivery system 20 may range from 12Fr to 16Fr.
[0065] The embolic protection device 10 is crimped/ welded on the delivery system 20 using a polymeric tube 30. The embolic protection device 10 may be fixed using the welding process. The temperature during process may range from 180°C-250°C. In an embodiment, the temperature is around 210°C. The process time may ranges from 10 seconds to 20 seconds. In an embodiment, the process time is 15 seconds.
[0066] The polymeric tube 30 may be made from polyurethane, PTFE, pebax, silicon, etc. In present invention, a tube made with polyurethane is used. The inner diameter of the polymer tube 30 may range from 4.0mm to 6.0mm and the thickness may range from 50µm to 200µm. In an embodiment, the inner diameter and the thickness of the polymer tube 30 are about 4.6mm and 150µm respectively.
[0067] The present invention will be now explained with the help of following example:
[0068] Example 1:
[0069] An embolic protection device having a frame with six arms of 33mm length and width of 1 mm was used. All the arms included three pairs of holes having a diameter of 0.50mm for stitching the mesh on the inner surface of the frame. The embolic protection device had a blunt proximal end and was crimped on the transcatheter valve at the distal end before balloon. Embolic protection device frame was initially evaluated for uniformity of compression. However, it was observed that during compression, few of the arms overlapped with each other which increased the profile of the embolic protection device with delivery system in compressed state i.e. 19Fr. Further, punctures or damages were observed in the lumen. Due to increase in the profile, the size of the delivery sheath also increased which ultimately lead to need of larger puncture for insertion of embolic protection device with TAVR delivery system. This made the operating procedure challenging.
Example 2:
[0070] An embolic protection device having a frame including six arms with 33mm length and 0.8 mm width was used. Further, the arms were connected through the “V shaped” link. Additionally, all the arms were slightly curved inside at their distal end to prevent damage to the aorta lumen. Further, proximal end of the frame had a rhombus shaped cell and was crimped /welded the on transcatheter valve by a polyurethane tube with the help of the tube welding machine. The embolic protection device frame was initially evaluated for uniformity of crimping and no overlapping of arms was observed. Therefore, the embolic protection device with the delivery system achieved a low profile in the compressed state i.e. 17Fr. Due to the low profile, the size of the embolic protection device with TAVR delivery system reduced which led to need of minor puncture for insertion and easy operation procedure.
[0071] 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.