Claims:WE CLAIM
1. A delivery system (100) for implanting a neurovascular implant (1) in a single entry procedure, comprising:
a. an inner tube (110) having a proximal end (110a), a distal end (110b) and a slotted pattern;
b. at least two radiopaque markers provided on the inner tube (110), the at least two radiopaque markers include a proximal marker (113) and a distal marker (115);
c. the implant (1) provided on the inner tube (110) between the proximal marker (113) and the distal marker (115);
d. one or more resheathing pads (117) disposed on the inner tube (110) at a predefined distance from the proximal marker (113) such that the implant (1) interacts with at least a part of the resheathing pad(s) (117); and
e. a multi-layered outer sheath (130) including an outer layer (130c1), a middle layer (130c2) and an inner layer (130c3), the outer sheath (130) including a lumen in which the inner tube (110) is provided, the outer sheath (130) including a radiopaque marker band (130’) at its distal end (130b);
wherein, prior to delivery of the implant (1), the radiopaque marker band (130’) of the outer sheath (130) is in proximity with the distal marker (115) of the inner tube (110),
wherein, after the delivery of the implant, the radiopaque marker band (130’) of the outer sheath (130) is in proximity with the proximal marker (113) of the inner tube (110),
wherein, the implant (1) is resheathed until the radiopaque marker band (130’) of the outer sheath (130) does not align with the one or more resheathing pad (117).
2. The delivery system (100) as claimed in claim 1, wherein a proximal end (110a) of the inner tube (110) is coupled to the luer hub (150).
3. The delivery system (100) as claimed in claim 1, wherein a proximal end (130a) of the outer sheath (130) is coupled with the Y-hub (170).
4. The delivery system (100) as claimed in claim 1, wherein a distal end (110b) of the inner tube (110) is provided with a soft tip (111).
5. The delivery system (100) as claimed in claim 1, wherein the proximal marker (113) is disposed towards the proximal end (110a) of the inner tube (110) at a predefined distance from a soft tip (111).
6. The delivery system (100) as claimed in claim1, wherein the distal marker (115) is disposed towards the distal end (110b) of the inner tube (110) adjacent to a soft tip (111).
7. The delivery system (100) as claimed in claim 1, wherein the resheathing pad (117) is disposed towards the distal end (110b) of the inner tube (110) at predefined distance from the proximal marker (113), predefined distance ranges from 0.5mm to 30mm.
8. The delivery system (100) as claimed in claim 1, wherein the slotted pattern of the inner tube (110) is produced by a cut over the inner tube (110) on at least a part of its length in a spiral configuration.
9. The delivery system (100) as claimed in claim 1, wherein the slotted pattern of the inner tube (110) is produced by winding two or more wire strands.
10. The delivery system (100) as claimed in claim 1, wherein the inner tube (110) includes a tapered distal region and a non-tapered proximal region.
11. The delivery system (100) as claimed in claim 1, wherein the proximal marker (113) is conical shaped.
12. The delivery system (100) as claimed in claim 1, wherein the distal marker (115) is rectangular shaped.
13. The delivery system (100) as claimed in claim 1, wherein the resheathing pads (117) include a coil like structure made of one or more wire strands to resheath the implant (1).
14. The delivery system (100) as claimed in claim 4, wherein the proximal marker (113) is disposed at a predefined distance from the soft tip (111), the predefined distance ranges from 10mm to 250mm.
15. A method (200) to deploy an implant (1) using the delivery system (100), comprising:
a. placing a guidewire (190) at an implantation site (10);
b. navigating the delivery system (100) with a pre-loaded crimped implant (1) to the implantation site (10);
c. positioning a distal marker (115) of an inner tube (110) of the delivery system (100) at a predefined location;
d. revealing the pre-loaded crimped implant (1) from within a lumen of an outer sheath (130) by placing a radiopaque marker band (130’) of the outer sheath (130) in close proximity with the proximal marker (113) leading to expansion of the pre-loaded crimped implant (1); and
e. retrieving the delivery system (100).
16. The method (200) as claimed in claim 15, wherein revealing the implant (1) includes pulling the outer sheath (130) over the inner tube (110).
17. The method (200) as claimed in claim 15, wherein revealing the implant (1) includes pushing the inner tube (110) within the outer sheath (130).
18. The method (200) as claimed in claim 15, wherein revealing the implant (1) includes pulling the outer sheath (130) and simultaneously pushing the inner tube (110). ,
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:
DELIVERY SYSTEM FOR NEUROVASCULAR DEVICES

2. APPLICANT:
Meril Life Sciences Pvt. Ltd., an Indian company of the address Survey No. 135/139 Bilakhia House, Muktanand Marg, Chala, Vapi- 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 invention relates to a delivery system. More specifically, the present invention relates to a microcatheter based delivery system for neurovascular devices.
BACKGROUND
[002] Intracranial aneurysm refers to a bulge or ballooning in a blood vessel of the brain. Intracranial aneurysm can leak or rupture causing internal brain to bleed. Intracranial aneurysm occurs within the neurovasculature at various vessel branch points for example, aneurysms of anterior neurovasculature include ICA (Internal Carotid Artery) aneurysms, superior hypophysial artery aneurysms, ophthalmic artery aneurysms, anterior choroidal aneurysms, etc. Aneurysms of posterior neurovasculature include anterior inferior cerebellar artery (AICA) aneurysms, posterior inferior cerebellar artery (PICA) aneurysms, superior cerebellar artery (SCA) aneurysms, etc.
[003] There are several known methods for treatment of aneurysms for example, surgical clipping across the artery which feeds the aneurysm, coiling method, flow diversion, etc. These treatment options require a physician to perform an in vivo procedure which generally involves implanting a device with the help of a delivery system through the neurovasculature of the patient.
[004] Generally, the implantation procedure using conventional delivery systems involves guidewire insertion at a targeted location followed by a microcatheter entry at the target location over the guidewire. Then the guidewire is removed and the delivery system along with an implant is inserted inside the microcatheter to deploy the implant.
[005] The conventional operational procedure to deploy the implant requires multiple insertions at a puncture site to access the implantation site via microcatheters, guide wires, implant delivery system, saline or contrast fluids etc. In said procedures, multiple insertions may increase the chance of procedural errors because the physician is required to follow multiple steps to insert different accessories.
[006] Making multiple insertions using the conventional delivery systems may not be feasible when dealing with complicated vasculature like intracranial arteries. Intracranial arteries are very complicated due to its anatomy which involves tortuous cavernous pathway and/or narrowing of artery. Most of the diabetic patients may have scattered occlusion inside their intracranial arteries which makes the said arteries very narrow.
[007] Further, during the implantation procedure, there is a high risk of kinking the conventional delivery system and/or the delivery wire (guidewire). Hence, the delivery system requires more force to push for deploying the implant. This may further damage or adversely change the implant design and construction. Further, there is a chance of rupturing the microcatheter of the delivery system which may create problems during retrieval of the system from an introducer sheath.
[008] In the conventional delivery system, a resheathing pad made up of a single wire of a radiopaque material is provided over the delivery wire which provides grip to an inner surface of the implant resulting in a resheathing functionality. However, the resheathing functionality is very primitive when the delivery system is used in vivo. In addition, the conventional delivery systems do not include any provision for multiple resheathing to allow accurate placement of the implant.
[009] Further, the delivery system contains a holding member to hold/fix an end of the implant. In addition to the holding member, other components are provided to push the implant out of the delivery system at the implantation site. In some cases, once the implant is deployed, the holding member adversely effects the retrieval of the delivery system inside the microcatheter.
[0010] The conventional delivery systems have compromised flexibility as well as reduced push force inside the tortuous pathways due to the vulnerability of the delivery wire to kink or damage during the procedure.
[0011] Therefore, there arises a requirement of a neurovascular delivery system which overcomes the aforementioned challenges associated with the conventional solutions.
SUMMARY
[0012] The present invention relates to a delivery system for implanting a neurovascular implant in a single entry procedure. The delivery system includes an inner tube, at least two radiopaque markers, the implant, one or more resheathing pad, and a multi-layered outer sheath. The inner tube includes a proximal end, a distal end and a slotted pattern. The at least two radiopaque markers are provided on the inner tube. The at least two radiopaque markers include a proximal marker and a distal marker. The implant is provided on the inner tube between the proximal marker and the distal marker. The one or more resheathing pads is disposed on the inner tube at a predefined distance from the proximal marker such that the implant interacts with at least a part of the resheathing pad(s). The multi-layered outer sheath including an outer layer, a middle layer and an inner layer. The outer sheath includes a lumen in which the inner tube is provided. The outer sheath includes a radiopaque marker band at its distal end. Prior to delivery of the implant, the radiopaque marker band of the outer sheath is in proximity with the distal marker of the inner tube. After the delivery of the implant, the radiopaque marker band of the outer sheath is in proximity with the proximal marker of the inner tube. The implant is resheathed until the radiopaque marker band of the outer sheath does not align with the one or more resheathing pad.
[0013] The present invention further relates to a method to deploy an implant using the delivery system of the present invention. The method includes placing a guidewire at an implantation site; navigating the delivery system with a pre-loaded crimped implant to the implantation site; positioning a distal marker of an inner tube of the delivery system at a predefined location; revealing the pre-loaded crimped implant from within a lumen of an outer sheath by placing a radiopaque marker band of the outer sheath in close proximity with the proximal marker leading to expansion of the pre-loaded crimped implant; and retrieving the delivery system.
[0014] 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
[0015] 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 instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale.
[0016] Fig. 1 depicts a delivery system 100 in accordance with an embodiment of the present invention.
[0017] Fig. 2 depicts a magnified view of the delivery system 100 in accordance with an embodiment of the present invention.
[0018] Fig. 3a and 3b depict an inner tube 110 in accordance with an embodiment of the present invention.
[0019] Fig. 4 depicts a soft tip 111 in accordance with an embodiment of the present invention.
[0020] Fig. 5 depicts a proximal marker 113 in accordance with an embodiment of the present invention.
[0021] Fig. 6 depicts a distal marker 115 in accordance with an embodiment of the present invention.
[0022] Fig. 7 depicts a resheathing pad 117 in accordance with an embodiment of the present invention.
[0023] Fig. 8 depicts an outer sheath 130 in accordance with an embodiment of the present invention.
[0024] Fig. 8a depicts a cross-sectional view of the outer sheath 130 in accordance with an embodiment of the present invention.
[0025] Fig. 9 illustrates a flowchart of a method 200 to deploy an implant 1 using the delivery system 100 in accordance with an embodiment of the present invention.
[0026] Fig. 9a-e depicts the delivery system 100 with respect to the method 200 in accordance with an embodiment of the present invention.
[0027] Fig. 10 depicts the delivery system 100 used in a stenosed pathway in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE DRAWINGS
[0028] 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.
[0029] 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.
[0030] 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.
[0031] 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.
[0032] In accordance with the present disclosure, an integrated microcatheter based delivery system (or delivery system) used to deploy a self-expandable implantable device (or implant) is disclosed. Implant may include without limitation a flow diverter, a coil, a stent, etc. The delivery system of the present invention can easily traverse the tortuous anatomy of cavernous pathway / intracranial artery for the treatment of intracranial aneurysm and/or stenosis.
[0033] The delivery system of the present invention is a ready to use microcatheter based delivery system which includes a pre-loaded implant. Further, the integrated delivery system of the present invention enables a physician to perform a single entry implantation procedure, i.e. the delivery system can by itself guide the implant through tortuous vasculature and deploy the implant at an implantation site without the need of any unnecessary accessories. The delivery system has high flexibility and excellent push force which renders the delivery system very easy to operate and easy to push. Moreover, the delivery system facilitates accurate placement of the implant at an implantation site without any structural deformation, damage and/or kink to the surface of the implant. The implantation site includes without limitation an intracranial artery, internal carotid artery, middle cerebral artery, anterior and posterior cerebral artery, peripheral artery, etc. After implantation, the delivery system facilitates easy retrieval from the body lumen without any problem. The delivery system has an outer profile of 2Fr-3Fr.
[0034] The delivery system of the present invention includes an outer sheath and an inner tube. The outer sheath acts as a microcatheter and provides optimal flexibility and kink resistance. The inner tube is placed inside the outer sheath and allows a guidewire to pass through for placement at an intracranial location (implantation site). The inner tube acts as a delivery wire and mimics the flexibility and kink resistance of the guidewire. The delivery system of the present invention does not require additional accessories like catheters and holding members for deployment of the Implant.
[0035] The delivery system includes a plurality of radiopaque markers which aid in visualization of the delivery system under fluoroscopic examination overcoming the low radiopacity of the implantation site. In an embodiment, the inner sheath of the delivery system includes a conical-shaped proximal marker. The unique design of a proximal marker (conical-shaped) helps to minimize the friction between a lumen of the outer sheath and an outer surface of the proximal marker. The proximal marker also acts as a pusher by pushing the implant towards a distal end of the delivery system during a deployment process into the body lumen. In another embodiment, the inner tube includes a rectangular-shaped distal marker. The rectangular shape of the marker helps to better locate and position the implant at the aneurysm neck during the deployment of the implant. Further, a radiopaque marker band of the outer sheath helps the physician to determine resheath-ability of the implant and successful deployment of the implant.
[0036] The inner tube can easily slide within the lumen of the outer sheath. The implant is loaded within the lumen of the outer sheath and over the inner tube for implantation. For example, the implant may be partially rests over one or more resheathing pads between the proximal and distal marker. The unique design of the resheathing pad (made of two wire strands) enhances the friction between an inner surface of the implant and the resheathing pad. The resheathing pad is disposed adjacent to the proximal marker over the inner tube of the delivery system. The disposition of the resheathing pad along with enhanced friction increases the chances of multiple resheathing of the implant even when 60% to 80% of the implant is deployed.
[0037] The delivery system of the present invention is able to deploy the implant within a patient’s neurovasculature in a single entry (in contrast to multiple entries) procedure, i.e. a physician has to insert the delivery system over a guidewire once the guidewire has been placed at the implantation site (also known as over the wire or OTW mechanism). Due to the simplicity of the single entry procedure, the delivery system of the present invention reduces time to deploy the implant and minimizes deployment errors. Further, due to the OTW mechanism and excellent flexibility of the delivery system, the delivery system can easily be navigated through the tortuous pathway in a smooth manner.
[0038] Now referring to the figures, Fig. 1 depicts an integrated delivery system 100 of the present invention. The delivery system 100 includes an inner tube 110, an outer sheath 130, a luer hub 150, a Y-hub 170 and a guide wire 190, etc. Further, delivery system 100 includes a loaded and crimped neurovascular implant 1 (shown in Fig. 2). The neurovascular implant 1 may include without limitation a flow diverter, a coil, a stent, etc. The delivery system 100 may have a length defined by a proximal end 100a and a distal end 100b of the delivery system 100. The length of the delivery system 100 may range from 1000mm to 2000mm. In an embodiment, the length of the delivery system 100 is 1500mm.
[0039] The delivery system 100 is a ready to use microcatheter based delivery system which may include a pre-loaded implant 1 (as shown in Fig. 2). The delivery system 100 facilitates accurate placement of the implant 1 at an implantation site without any structural deformation, damage and kink to the surface of the implant 1. After implantation, the delivery system 100 facilitates easy retrieval from the body lumen without any problem.
[0040] The inner tube 110 of the delivery system 100 may be made of a material including but not limited to stainless steel, cobalt chromium, nickel alloys (nitinol), etc. In an embodiment, the inner tube 110 is made of nickel and titanium alloy, i.e. nitinol which provides better strength, flexibility and kink resistance. The guidewire 190 passes through the inner tube 110 for placement at the implantation site. The inner tube 110 acts as a delivery wire and mimics the flexibility and kink resistance of the guidewire 190.
[0041] As shown in Fig. 2, the inner tube 110 may include a proximal end 110a and a distal end 110b. In an embodiment, the distal end 110b is more flexible than the proximal end 110a. The proximal end 110a of the inner tube 110 helps to better push the inner tube 110 once the delivery system 100 reaches the implantation site. The distal end 110b of the inner tube 110 easily conforms to the tortuous neurovasculature without kinking. The inner tube 110 may be utilized to transmit a torque or a pushing force because of its exceptional whip free properties and high resistance to kinks.
[0042] The proximal end 110a of the inner tube 110 may be coupled to the luer hub 150 (depicted in Fig. 1) via any means including but not limited to adhesives bonding, ultraviolet glue, etc. In an embodiment, the proximal end 110a of the inner tube 110 is coupled to the luer hub 150 with the help of 209-grade ultraviolet gluing technique, i.e. after applying a medical grade glue; it is cured under ultraviolet radiation. The luer hub 150 facilitates insertion of the guidewire 190 inside the inner tube 110 (depicted in Fig. 1).
[0043] The inner tube 110 may include a tapered distal region and a non-tapered proximal region. The length of the inner tube 110 may be defined by the proximal end 110a and the distal end 110b ranging from 500mm to 2000mm, preferably from 800mm to 1700mm. The inner tube 110 may have an inner diameter ranging from 0.05mm to 0.65mm, preferably from 0.10mm to 0.50mm. The distal region of the inner tube 110 may have a tapered outer diameter ranging from 0.10mm to 0.70mm, preferably from 0.30mm to 0.60mm. The proximal region of the inner tube 110 may have a non-tapered outer diameter ranging from 0.20mm to 0.90mm, preferably from 0.40mm to 0.70mm. In an embodiment, the length and inner diameter of the inner tube 110 is 1500mm, and 0.46mm respectively. In an embodiment, the tapered outer diameter of the distal region of the inner tube 110 ranges from 0.40mm to 0.55mm, with the distal end 110b having an outer diameter of 0.48mm. In an embodiment, the non-tapered outer diameter of the proximal end 110a of the inner tube 110 is 0.55mm.
[0044] The inner tube 110 may include one or more layers to facilitate variable flexibility along its length thereby providing better control during deployment of the implant 1. For example, one or more region of the inner tube 110 may be multi-layered to increase stiffness and/or may be single layered to increase flexibility. The inner tube 110 addresses various clinical challenges for navigating torturous vascular pathways by providing better flexibility and trackability. The inner tube 110 facilitates improved transmittance of torque and/or pushing force.
[0045] In an embodiment, the inner tube 110 is a hollow cylindrical tube. The inner tube 110 may include a slotted pattern throughout its length or only on a part of its length (for example, the tapered distal region). The slotted pattern of the inner tube 110 may provide better kink resistance, and enhanced flexibility. Further, due to the slotted pattern, the inner tube 110 is rendered as a light weight structure for easy navigation through the tortuous neurovasculature.
[0046] The slotted pattern of the inner tube 110 may be produced by coiling, laser cutting, or other functionally equivalent means. In an embodiment as shown in Fig. 3a, the slotted pattern on the inner tube 110 is produced by laser cutting the inner tube 110. The inner tube 110 may be laser cut along its entire length or only a part of its length to produce the slotted pattern. The slotted pattern of the inner tube 110 provides better flexibility, trackability and torquability for implantation of the neurovascular implant 1 through torturous and narrowing vascular pathways. In an exemplary embodiment, the inner tube 110 is laser cut in a spiral configuration to produce the slotted pattern. The spiral laser cut of the inner tube 110 may have a pitch ‘A’ ranging from 5mm to 50mm, preferably 20mm to 35mm. The flexibility of the inner tube 110 may depend on the pitch of the spiral laser cut.
[0047] In an alternate embodiment as depicted in Fig. 3b, the slotted pattern of the inner tube 110 is produced by winding two or more wire strands to form a hollow cylinder. Other equivalent techniques like braiding, coiling, etc. are within the scope of the teachings of the present invention. The wire strands of the inner tube 110 may be wounded in any order including but not limited to helical winding or twisting on a pre-defined mandrel, etc. In an exemplary embodiment, the inner tube 110 is made by winding three wire strands helically to form a hollow cylindrical tube. The coiling of the plurality of wire strands of the inner tube 110 provides better flexibility, torquability and kink resistance for implantation of the neurovascular implant 1 through torturous and complex neurovascular pathways.
[0048] The plurality of wires (or multi-layer shaft wire) of the inner tube 110 may be made of a material including but not limited to stainless steel, platinum, nitinol, platinum-tungsten wires. In an embodiment, the plurality of wires of the inner tube 110 is made of nitinol which provides kink resistance along with better flexibility and torque transmission. Each wire strand of the inner tube 110 may have a diameter ranging from 0.01mm to 0.10mm, preferably from 0.03mm to 0.08mm. In an embodiment, the diameter of the wire strand is 0.05mm.
[0049] Further, the distal end 110b of the inner tube 110 may be provided with a soft tip 111. The soft tip 111 may be attached on the distal end 110b by any means including but not limited to adhesive, ultraviolet gluing, spot welding, laser welding, etc. In an embodiment, the soft tip 111 is bonded to the distal end 110b of the inner tube 110 by medical grade adhesive for better bonding strength. The soft tip 111 provides better guidance and/or may prevent tissue trauma while inserting the delivery system 100 and deploying the implant 1.
[0050] The soft tip 111 may be made of a material including but not limited to polytetrafluoro ethylene (PTFE), HDPE, Pebax or any other polyester. In an embodiment, the soft tip 111 is made of Pebax, due to its light weight and kink resistance provides optimal flexibility and stiffness for atraumatic deployment of the implant 1. Further, Pebax includes other excellent material properties like overmolding, wide ranges of softness and flexibility, chemical resistance and easy processing.
[0051] The soft tip 111 (as depicted in Fig. 4) may include an inner cavity 111a. The soft tip 111 may be tapered. The soft tip 111 may have a proximal end 111b and a distal end 111c. The soft tip 111 may include a length between the proximal end 111b and the distal end 111c in a range of 1mm to 15mm, preferably from 5mm to 10mm. In an embodiment, the length of the soft tip 111 is 8mm.
[0052] The soft tip 111 may have a proximal outer diameter ranging from 0.40mm to 1.20mm, preferably from 0.60mm to 1.00mm. The soft tip 111 may have a distal outer diameter ranging from 0.10mm to 0.80mm, preferably from 0.50mm to 0.70mm. The soft tip 111 may have an internal diameter ranging from 0.10mm to 0.80mm, preferably 0.40mm to 0.60mm. In an embodiment, the proximal outer diameter, distal outer diameter, internal diameter of the soft tip 111 is 0.90mm, 0.60mm, and 0.50mm respectively.
[0053] Further, at least two radiopaque markers may be provided on the inner tube 110. The radiopaque markers may be made of a material including but not limited to stainless steel, gold, platinum, platinum-iridium or platinum tungsten. In an embodiment, the radiopaque markers are made of platinum-iridium. The at least two radiopaque markers provide enhanced visibility through the reduced radiopacity of thick skull bones thereby giving the physician an added advantage of better judgement and control during deployment of the implant 1.
[0054] The radiopaque markers may be coupled to the inner tube 110 by any means including but not limited to adhesives, laser welding, spot welding, ultraviolet gluing technique, or a combination thereof. In an embodiment, the radiopaque markers are coupled to the inner tube 110 with the help of medical grade adhesives and welding for better affixation.
[0055] As shown in Fig. 2, the inner tube 110 may be provided with a proximal marker 113 and a distal marker 115. The proximal marker 113 may be disposed towards the proximal end 110a at a predefined distance from the soft tip 111. The predefined distance may be in a range of 10mm to 250mm, preferably from 20mm to 220mm. The predefined distance may depend upon a length of a crimped implant which in turn is dependent upon the implant’s property. For example, in case of a braided implant, the length of the crimped implant is more than the length of the implant, whereas in case of a laser cut implant, the length of the crimped implant does not differ from the length of the implant. In an exemplary embodiment, for a 35mm long implant having a diameter of 3mm, the proximal marker 113 is disposed 115mm to 125mm from the soft tip 111. The proximal marker 113 acts as a pusher to push the implant 1 during deployment of the implant 1. Further, the proximal marker 113 helps the physician to determine if the implant 1 is successfully deployed at the implantation site (described below).
[0056] The proximal marker 113 may have any shape including but not limited to circular, flat, conical, or rectangular shape. In an embodiment as depicted in Fig. 5, the proximal marker 113 is conical in shape. The conical shape of the proximal marker 113 helps to minimize friction between a lumen of the outer sheath 130 and the proximal marker 113. Further, due to the conical shape of the proximal marker 113, it reduces the chances of overlap between the implant 1 and a surface of the proximal marker 113 while pushing the implant 1 during deployment.
[0057] The proximal marker 113 may have a proximal outer diameter ranging from 0.25mm to 0.85mm, preferably from 0.40mm to 0.70mm. The proximal marker 113 may have a distal outer diameter ranging from 0.40mm to 0.90mm, preferably from 0.55mm to 0.75mm. The proximal marker 113 may have an inner diameter ranging from 0.10mm to 0.80mm, preferably 0.40mm to 0.60mm. The proximal marker 113 may have a length ranging from 0.50mm to 3.5mm, preferably from 1mm to 2.5mm. In an embodiment, the proximal outer diameter, the distal outer diameter, the inner diameter and the length of the proximal marker 113 is 0.62mm, 0.65mm, 0.50mm and 2.00mm respectively. The proximal outer diameter and the distal outer diameter of the proximal marker 113 restrict any longitudinal movement of the implant 1 during deployment of the implant 1 at the implantation site.
[0058] The distal marker 115 may be disposed towards the distal end 110b of the inner tube 110 adjacent to the soft tip 111. In an embodiment as depicted in Fig. 2, the distal marker 115 is present at a junction between the implant 1 and the soft tip 111. Such disposition of the distal marker 115 may help to precisely position the implant 1 during deployment of the implant 1 at the aneurysm neck (implantation site). Further, the disposition of the distal marker 115 may help determine the crimped profile/length of the implant 1 when the implant 1 is loaded between the inner tube 110 and the outer sheath 130.
[0059] The distal marker 115 may have any shape including but not limited to circular, flat, conical, rectangular shape. In an embodiment as shown in Fig. 6, the distal marker 115 is rectangular in shape. The rectangular shape of the distal marker 115 helps to better locate and/or position the implant 1 at the implantation site (aneurysm neck) during the deployment of the implant, i.e. it provides a reference point to the physician during deployment of the implant 1.
[0060] The distal marker 115 may have an outer diameter ranging from 0.25mm to 0.85mm, preferably from 0.40mm to 0.70mm. The distal marker 115 may have an inner diameter ranging from 0.10mm to 0.80mm, preferably 0.40mm to 0.60mm. The distal marker 115 may have a length ranging from 0.10mm to 3.5mm, preferably from 0.50mm to 2.5mm. The distal marker 115 may have a width ranging from 0.01mm to 0.09mm, preferably from 0.02mm to 0.08mm. In an embodiment, the outer diameter, the inner diameter, the length and the width of the distal marker 115 is 0.62mm, 0.50mm, 2mm and 0.06mm respectively.
[0061] The inner tube 110 may also include one or more resheathing pads 117 to resheath the implant, as required by the physician, during deployment of the implant 1. In addition to the proximal marker 113 and distal marker 115, the resheathing pads 117 may also act as radiopaque markers thereby helping the physician deploy the implant 1 with better judgment. In an embodiment as shown in Fig. 2, the inner tube 110 is provided with a single resheathing pad 117. When the implant 1 is crimped and loaded between the inner tube 110 and a lumen of the outer sheath 130, at least a part of an inner surface (for example a proximal region) of the implant 1 may interact with at least a part of the resheathing pad(s) 117.
[0062] The resheathing pad 117 may be disposed at a predefined position on the inner tube 110. The position of the resheathing pad 117 contributes in determination of the frictional forces between the resheathing pad 117 and the inner surface of the implant 1. The frictional force between the implant 1 and resheathing pad 117 may in turn determine the efficiency of the resheathing of the implant 1 within the outer sheath 130 during the deployment of the implant 1. In an embodiment, the resheathing pad 117 may be disposed adjacent the proximal marker 113. The resheathing pad 117 may be disposed at a predefined distance from the proximal marker 113 towards the distal end 110b of the inner tube 110. The predefined distance may be in a range of 0.5mm to 30mm. In an embodiment, the resheathing pad 117 is disposed at a distance of 15mm from the proximal marker 113 to provide optimal resheathing of the implant 1. Such disposition of the resheathing pad 117 along with enhanced friction (described below) increases the chances of multiple resheathing (i.e. resheath-ability) of the implant 1 even when 60% to 80% of the implant 1 is deployed.
[0063] In an alternate embodiment, the inner tube 110 is provided with more than one resheathing pad 117; for example, three resheathing pads (not shown), namely a first pad, a second pad and a third pad. The first pad may be disposed at a distance from the proximal marker 113, the distance ranging from 2mm to 10mm. The second pad may be disposed at a distance from the proximal marker 113, the distance ranging from 10mm to 20mm. The third pad may be disposed at a distance from the proximal marker 113, the distance ranging from 20mm to 30mm. In an embodiment, the first pad, the second pad and the third pad are disposed at 5mm, 15mm and 25mm respectively from the proximal marker 113. Multiple resheathing pads 117 provide enhanced support to the implant 1 in the crimped state, enabling easy multiple resheathing and/or better grip over the implant 1 thereby resulting in accurate deployment of the implant 1.
[0064] The resheathing pad 117 may be made of a material including but not limited to platinum, platinum-tungsten, nitinol, silicone, rubber or pebax. In an embodiment, the resheathing pad 117 may be made of platinum-tungsten.
[0065] The resheathing pad 117 may have any structure including but not limited to tubular, spring/coil like structure. In an embodiment as depicted in Fig. 7, the resheathing pad 117 resembles a coil like structure. The coil like structure of the resheathing pad 117 helps to maintain strong longitudinal grip over the implant 1.
[0066] The coil like structure of the resheathing pad 117 may be made of one or more wire strands. In an embodiment as depicted in Fig. 7, the resheathing pad 117 is made of two wire strands namely a first wire 117a and a second wire 117b. Using two wire strands for the resheathing pad 117 increases the friction between the implant 1 and the resheathing pad 117 thereby improving the chances of resheathing of the implant 1 during deployment. The one or more wire strands of the resheathing pad 117 may have a diameter ranging from 0.010mm to 0.080mm, preferably from 0.040mm to 0.060mm. In an embodiment, the one or more wire strands of the resheathing pad 117 have a diameter of 0.050mm. In an exemplary embodiment, each wire strand making the coil like structure of the resheathing pad 117 includes a pitch which is equal to the diameter of the wire strand.
[0067] In an exemplary embodiment, the first wire 117a is made of nitinol and the second wire 117b is made of platinum. The first wire 117a provides better flexibility along with kink resistance. The second wire 117b provides optimal radiopacity for imaging through fluoroscopy.
[0068] The resheathing pad 117 may have an outer diameter ranging from 0.10mm to 1.80mm, preferably from 0.40mm to 1.40mm. The resheathing pad 117 may have an inner diameter ranging from 0.05mm to 1.20mm, preferably from 0.20mm to 1.00mm. The resheathing pad 117 may have a length ranging from 0.5mm to 5mm, preferably from 1.5mm to 4mm. In an embodiment, the outer diameter, the inner diameter and the length of the resheathing pad 117 is 0.55mm, 0.50mm and 3.00mm respectively.
[0069] Lastly, the delivery system 100 includes the outer sheath 130 (depicted in Fig. 8). The outer sheath 130 acts as a microcatheter which carries the inner tube 110, i.e. the outer sheath 130 may be provided around the inner tube 110; and holds the crimped and loaded implant 1 in between the lumen of the outer sheath 130 and the inner tube 110 thereby eliminating the need of any complicated accessories. The inner tube 110 may be operationally coupled to the outer sheath 130 such that the inner tube 110 may slide within a lumen of the outer sheath 130. The outer sheath 130 of the delivery system 100 gives an advantage to the physician to perform the deployment procedure in a single entry, i.e. physician has to just insert delivery system 100 over a guide wire 190 placed at the implantation site. Further, the outer sheath 130 provides optimal flexibility and kink resistance during deployment of the implant 1.
[0070] The outer sheath 130 may be tapered. The outer sheath 130 may have a length defined by a proximal end 130a and a distal end 130b ranging from 400mm to 1800mm, preferably from 600mm to 1600mm. The outer sheath 130 may have an inner diameter ranging from 0.40mm to 0.80mm, preferably from 0.50mm to 0.70mm. The outer sheath 130 may have a proximal outer diameter ranging from 0.75mm to 1.20mm, preferably 0.85mm to 1.10mm. The outer sheath 130 may have a distal outer diameter ranging from 0.70mm to 1.10mm, preferably 0.80mm to 1.00mm. In an embodiment, the length, the inner diameter, the proximal outer diameter and the distal outer diameter of the outer sheath 130 is 1300mm, 0.68mm, 0.97mm and 0.90mm respectively. The outer sheath 130 may have a low profile size ranging from 1Fr to 4Fr.
[0071] The outer sheath 130 may be made of a material including but not limited to different grades of pebax (pebax 7233, pebax 5533, pebax 7232, etc), PTFE, PEEK, nylon, HDPE, FEP polyurethane, etc. In an embodiment, the outer sheath 130 is made of pebax or made of two or more tubing component.
[0072] The outer sheath 130 may be made of one or more layers (or multi-layered) to achieve desired flexibility and kink resistance properties. The one or more layers of the outer sheath 130 may be made of a solid material, a braided material, a coiled material or a combination thereof. In an embodiment as depicted in Fig. 8a, the outer sheath 130 is made up of three layers namely an outer layer 130c1, a middle layer 130c2 and an inner layer 130c3.
[0073] In an embodiment, the outer layer 130c1 is made of pebax. Pebax is a light weight material having excellent overmolding property and is easily processed. Due to the said properties of pebax, it is considered an appropriate material for preparing catheters, tubing and multi lumen tubing. The outer layer 130c1 provides atraumatic movement of the delivery system 100 within the neurovasculature.
[0074] In an embodiment, the middle layer 130c2 is made by braiding a plurality of wires ranging from 4 to 32 wires. The braiding of the middle layer 130c2 may be made of a metal or an alloy. In an embodiment, the braiding of the middle layer 130c2 is made up of 16 stainless steel flat wires. Stainless steel flat wire provides enhanced strength optimal hardness/stiffness to the middle layer 130c2. Further, stainless steel provides other advantages like excellent corrosion resistance and high ductility. In an exemplary embodiment, the braided middle layer 130c2 is 0.017mm thick and 0.076mm wide. The middle layer 130c2 provides optimal flexibility with kink resistance.
[0075] In an embodiment, the inner layer 130c3 is made of PTFE. The inner layer130c3 may define the lumen of the outer sheath 130. And the inner layer 130c3 facilitates smooth deployment of the implant 1 with least frictional resistance, i.e. provides enhanced lubricity.
[0076] As shown in Fig. 1, the outer sheath 130 may include a proximal end 130a and a distal end 130b. The proximal end 130a may be coupled with the Y-hub 170 (depicted in Fig. 1) via any means including but not limited to adhesives bonding, ultraviolet glue, etc. In an embodiment, the proximal end 130a of the outer sheath 130 is coupled to the Y-hub 170 with the help of 209-grade ultraviolet gluing technique, i.e. after applying medical grade glue; it is cured under ultraviolet radiation.
[0077] The Y-hub 170, as the name suggests, includes three openings/ports. One of the three openings (say an out port) of the Y-hub 170 may be coupled to the outer sheath 130 (described above). One of the remaining opening (say an in port) of the Y-hub 170 may facilitate insertion of the inner tube 110 within the outer sheath 130 via the out port of the Y-hub 170. And lastly, a flush port of the Y-hub 170 facilitates insertion of saline solution, contrast media or similar substances. The Y-hub 170 further acts as a hemostatic valve to control bleed back thereby minimizing patient’s blood loss.
[0078] The outer sheath 130 may also include one or more radiopaque marker bands 130’. The radiopaque marker bands 130’ may be made of a material including but not limited to stainless steel, gold, platinum, platinum-iridium or platinum tungsten. In an embodiment, the radiopaque marker band 130’ is made of platinum-iridium.The radiopaque marker band 130’ may be disposed at the distal end 130b of the outer sheath 130 (as shown in Fig. 9b). The radiopaque marker band 130’ of the outer sheath 130 helps in resheath-ability and precise placement of the implant 1 at the implantation site. In an exemplary embodiment, the physician may try to resheath the implant 1 as long as the radiopaque marker band 130’ of the outer sheath 130 do not align with at least one of the resheathing pad(s) 117.
[0079] In an exemplary embodiment as depicted in Fig. 9, the delivery system 100 is used to deploy the implant 1 at an implantation site (aneurysm) 10 by a method 200. The method 200 enables the physician to perform a single entry implantation procedure, i.e. the delivery system 100 can by itself guide the implant 1 through tortuous vasculature and deploy the implant 1 at the implantation site 10 without the need of any other accessories or multiple entry of various sheaths or catheters. Due to the simplicity of the single entry procedure, the delivery system 100 reduces time to deploy the implant 1 and minimizes deployment errors. Further, it reduces loss of blood during the procedure as is rampant in conventional procedures. The method 200 begins at step 201, where the guidewire 190 may be placed at the implantation site 10 through a dermal puncture. In an exemplary embodiment, the guidewire 190 is placed at the aneurysm 10 via a femoral puncture site.
[0080] At step 203, the delivery system 100 may be inserted through the dermal puncture and navigated over the guidewire 190 to reach the implantation site 10 (as shown in Fig. 9a). The delivery system 100 may be inserted and navigated over the guidewire 190 such that the inner tube 110 of the delivery system 100 slides over the guidewire 190 to reach the implantation site 10.
[0081] At step 205, the distal marker 115 of the delivery system 100 may be positioned at a predefined location with respect to the implantation site 10. In an embodiment as shown in Fig. 9b, the distal marker 115 is placed at a neck of the aneurysm (implantation site) 10. As shown, the lumen of the outer sheath 130 includes an inner tube 110 carrying the implant 1. The preloaded crimped implant 1 is provided between the proximal marker 113 and distal marker 115 of the inner tube 110 as depicted. Further, at least a part of the inner surface (for example a proximal region) of the implant 1 interacts with at least a part of the resheathing pad(s) 117. Further, in the depicted embodiment relating to the initial configuration of the delivery system 100, the radiopaque marker band 130’ of the outer sheath 130 is disposed in close proximity to the soft tip 111 and/or the distal marker 115 of the inner tube 110.
[0082] At step 207, the implant 1 may be deployed at the implantation site 10 by revealing the implant 1 from within the lumen of the outer sheath 130. The implant 1 may be revealed by either pushing the inner tube 110 within the lumen of outer sheath 130, pulling the outer sheath 130 over the inner tube 110 or a combination thereof (as shown in Fig. 9c). In an exemplary embodiment, the outer sheath 130 is pulled and simultaneously, the inner tube 110 is pushed to deploy the implant 1. In yet another exemplary embodiment as shown in Fig. 9d, the outer sheath 130 is pulled over the inner tube 110 until the radiopaque marker band 130’ of the outer sheath 130 is in close proximity to the proximal marker 113 of the inner tube 110. Also, due to the proximal outer diameter and the distal outer diameter of the proximal marker 113, it restricts the longitudinal movement of the implant 1 while the outer sheath 130 is pulled. The placement of the radiopaque marker band 130’ of the outer sheath 130 in close proximity to the proximal marker 113 may provide a confirmation about a complete unsheathing and expansion of the crimped implant 1, i.e. successful deployment of the implant 1.
[0083] At an optional step 209, during deployment of the implant 1, the inner tube 110 may be partially or entirely resheathed within the lumen outer sheath 130 by either pulling the inner tube 110 within the lumen of outer sheath 130, pushing the outer sheath 130 over the inner tube 110 or a combination thereof. In an exemplary embodiment as shown in Fig. 9e, the inner tube 110 is resheathed within the outer sheath 130 such that the radiopaque marker band 130’ of the outer sheath 130 is again disposed in close proximity to the soft tip 111 and/or the distal marker 115 of the inner tube 110. The optional step 209 may enable the physician to resheath the implant 1 for reposition the delivery system 100 and/or the distal marker 115 as required. The implant 1 may only be resheathed until the radiopaque marker band 130’ of the outer sheath 130 does not align with the one or more resheathing pads 117.
[0084] In case the implant 1 is incompatible with the implantation site 10 (for example due to size of the implant) based on judgment of the physician, it may be preferable to continue the procedure with an implant with better compatibility. Implanting incompatiable implant may lead to medical complication in future, for example migration of the implant from the implantation site 10. The optional step 209 may also enable the physician to resheath the implant 1 and continue the method from step 203 by replacing the delivery system 100 with a similar delivery system having the implant with better compatibility.
[0085] At step 211, the delivery system 100 may be retrieved from the implantation site 10 and/or the dermal puncture.
[0086] The present invention may be supported by the following examples:
[0087] Example 1 (Prior art): A procedure using a guide wire based delivery system was performed to deploy an implant. An introducer sheath and a guiding catheter were inserted within a puncture at a femoral site to reach the aortic arch. After the guiding catheter reached the aortic arch, a guidewire was placed at the implantation site (intracranial artery) via the guiding catheter. A compatible microcatheter was inserted over the guidewire and placed at the implantation site. Thereafter, the guidewire inside the microcatheter was replaced by the delivery system including a delivery wire along with the implant. The delivery wire was pushed until the implant was deployed at the implantation site.
[0088] In the procedure performed using the guide wire based delivery system, it was observed that the procedure was unnecessarily difficult for the physician and vulnerable to clinical problems associated with stenosed tortuous arteries of the patient.
[0089] Example 2 (Present invention): In case of microcatheter based delivery system 100 of the present invention, the physician performed the procedure to deploy an implant 1 in a single entry (as shown in Fig. 9a-e), i.e. the physician inserted the delivery system 100, within a puncture at a femoral site, over the guidewire 190 once the guidewire 190 was placed at the implantation site (aneurysm) 10.
[0090] Even in extreme case (as shown in Fig 10), when imaging techniques showed tortuous pathways with scattered occlusions 11 due to which artery became narrow, the microcatheter based delivery system 100 of the present invention helped the physician to perform the procedure with ease and without any adverse complication including kinking or damage of the intracranial vessel or creation of emboli/clot, etc. Further, due to the single entry procedure performed via the delivery system 100, loss of blood from the puncture at the femoral site was significantly minimized.
[0091] 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.