Systems and methods for implant delivery

Abstract

Some embodiments of the present disclosure are directed generally to systems and methods for delivering an implant to a body vessel of a patient. Such disclosed implants may be a monofilament implant, and disclosed systems for implanting the implant may be automatic. Some embodiments may enable retraction of said implant back into the delivery system following partial exteriorization of the implant from the delivery system. Some embodiments may be configured for retraction of said implant from the patient's body following complete exteriorization of the implant from the delivery system. Some of the embodiments are directed at delivering a monofilament implant for preventing embolic stroke. Other embodiments are directed at preventing pulmonary embolism, occluding a body vessel such as the left atrial appendage, occluding a body passageway such as a patent foramen ovalae, stenting a body vessel, or releasing a local therapeutic agent such as a drug or ionizing radiation.

Claims

1. A method of delivering an embolism protection device (EPD) into a living body, comprising: determining the diameter of a target vessel at an implantation site; selecting an appropriate sized EPD for the target vessel based on the determined diameter of the target vessel; penetrating the skin adjacent the target vessel via a tip of a needle of a delivery device; advancing the tip of the needle towards the target vessel; penetrating the target vessel using the tip of needle; advancing a pusher of the delivery device toward the distal end of the needle; and withdrawing the needle and the pusher out of the target vessel; wherein the needle assumes an approximately perpendicular orientation with respect to a plane tangent to an arterial wall at the puncture site.

2. The method of claim 1, wherein the EPD includes a stem, and the pusher is configured such that the distance between the distal tip of the pusher and the distal end of the needle is approximately equal to the length of the stem, resulting in the EPD assuming a correct position within the target vessel.

3. The method of claim 1, wherein the method is performed under imaging guidance comprising at least one of ultrasound, high resolution ultrasound, x-ray fluoroscopy, CT, and MRI.

4. The method of claim 1, wherein advancing comprises placing the tip of the needle a predetermined distance from the vessel puncture site.

5. The method of claim 1, wherein the EPD assumes a predetermined orientation after exteriorization.

6. The method of claim 1, wherein the tip of the needle is placed about 1 mm into the lumen of the target vessel.

7. The method of claim 1, wherein the EPD is pre-loaded into the delivery device.

8. The method of claim 1, wherein selection of the EPD comprises selecting the maximal diameter of the deployed state of the EPD is between about 0.5 to about 1 mm less than the diameter of the vessel.

9. The method of claim 1, wherein the selecting of the appropriately sized EPD comprises under-sizing the EPD along at least one dimension of the EPD relative to the diameter of the target vessel.

10. The method of claim 9, further comprising oversizing the EPD along another dimension of the EPD relative to the diameter of the target vessel.

11. A method of delivering an embolism protection device (EPD) into a living body, comprising: determining the diameter of a target vessel at an implantation site; selecting an appropriate sized EPD for the target vessel based on the determined diameter of the target vessel; penetrating the skin adjacent the target vessel via a tip of a needle of a delivery device; advancing the tip of the needle towards the target vessel; penetrating the target vessel using the tip of needle; advancing a pusher of the delivery device toward the distal end of the needle; and withdrawing the needle and the pusher out of the target vessel; wherein selection of the EPD comprises selecting the maximal diameter of the deployed state of the EPD is between about 0.5 to about 1 mm less than the diameter of the vessel.

12. A method of delivering an embolism protection device (EPD) into a living body, comprising: determining the diameter of a target vessel at an implantation site; selecting an appropriate sized EPD for the target vessel based on the determined diameter of the target vessel; penetrating the skin adjacent the target vessel via a tip of a needle of a delivery device; advancing the tip of the needle towards the target vessel; penetrating the target vessel using the tip of needle; advancing a pusher of the delivery device toward the distal end of the needle; and withdrawing the needle and the pusher out of the target vessel; wherein the selecting of the appropriately sized EPD comprises under-sizing the EPD along at least one dimension of the EPD relative to the diameter of the target vessel.

13. The method of claim 12, further comprising oversizing the EPD along another dimension of the EPD relative to the diameter of the target vessel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention may be better understood with reference to the accompanying drawings and subsequently provided detailed description:

(2) FIGS. 1A-E depict an implant system and its corresponding method of use according to some embodiments of the present disclosure. The system comprises a pusher that configured to diminish the effect of buckling.

(3) FIG. 2A-C depict various needle designs according, to some embodiments of the present disclosure. These designs render the needle more visible under ultrasound imaging and less traumatic to the target vessel.

(4) FIGS. 3A-F depict an implant system and its corresponding method of use according to some embodiments of the present disclosure. The system comprises a first introducer needle and a second, vessel-puncturing needle that is slidable within the introducer needle lumen.

(5) FIGS. 4A-E depict an implant system according to some embodiments of the present disclosure. Under certain conditions the system allows for interiorization of the implant back into the needle lumen.

(6) FIGS. 5A-D depict an implant system according to some embodiments of the present disclosure. The system features mechanical engagement and disengagement of the implant and the pusher.

(7) FIGS. 6A-C depict an automatic delivery system comprising a motor according to some embodiments of the present disclosure. The motor axis is approximately perpendicular to the needle.

(8) FIGS. 7A-C depict an automatic delivery system comprising a motor according to some embodiments of the present disclosure. The motor axis is approximately parallel to the needle.

(9) FIGS. 8A-C depict an automatic delivery system in which power is transmitted from a motor to a push wire via rollers.

(10) FIGS. 9A-H depict a removable implant system and its corresponding method of use according to some embodiments of the present disclosure.

DETAILED DESCRIPTION OF SOME OF THE EMBODIMENTS

(11) Reference is now made to FIGS. 1A-E, which depict an implant system and method for implant delivery according to some embodiments of the present disclosure. System 1 may comprise a pusher 10, an implant 12, and a needle 11. Pusher 10 may comprise a push wire 14 and a stabilizing tube 13.

(12) The push wire and the stabilizing tube may be rigidly connected at their proximal ends by a suitable method such as, for example, welding, gluing, or screwing. Push wire 14 is configured to be slidably received within the proximal end of the lumen of needle 11. Stabilizing tube 13 is configured to slidably receive the proximal end of needle 11.

(13) Stabilizing tube 13 diminishes the deleterious effect of buckling of wire 14 as it is being pushed into the lumen of needle II. This is because stabilizing tube 13 may be made sufficiently stiff as to not buckle under the push force required to slide implant 12 within the lumen of needle 11, and push wire 14, even if it buckles, is kept by the internal walls of stabilizing tube 13 substantially collinear with the lumen of needle 11. Push wire 13 is thus able to transmit push force from its proximal to its distal end even if it buckles.

(14) Push wire 14 may be made from metal or plastic. Suitable metals include, for example, stainless steel and nitinol. Stabilizing tube 13 may also be made from metal or a plastic. Suitable metals include, for example, stainless steel and nitinol.

(15) Implant 12 may be made from a super elastic alloy, such as nitinol. The implant may be of monofilament construction (as depicted in in FIG. 1A), but may also may be of a different construction (for example, a multi-filament construction or a cut-tube construction). The implant assumes an un-deployed, substantially linear state (as in FIG. 1A) or a deployed, functional state (as in FIG. 1E). The implant is constrained to its un-deployed substantially linear state by the needle, in whose distal lumen end it initially resides. Upon exteriorization from the needle (FIGS. 1C-1E), the implant retains its deployed, functional state by virtue of its super-elasticity.

(16) Whenever implant 12 is a monofilament implant, the wire from which it is made may have a circular cross-section. The diameter may range from about 0.05 mm to about 1 mm.

(17) Implant 12 may be an embolic protection device for stroke prevention, an embolic protection device for pulmonary embolism prevention, a vessel occlusion device such as a left atrial appendage occluder, a therapeutic agent delivery platform a stent, or any other medical implant that fits in its un-deployed state into the lumen of a thin needle. Implant 12 may be any implant that can be twisted into its functional shape from a monofilament. Implant 12 may be, but is not limited to, any of the implants described in U.S. Provisional Patent Applications Nos. 61/653,676, 61/693,979, 61/746,423, 61/754,264, as well as PCT publication nos. WO2013/179137, WO2014/102767 and WO2014/111911 (the entire disclosures of which all herein incorporated by reference).

(18) In some embodiments, the functional, deployed state of implant 12 may comprise a substantially straight stem 17, configured to traverse the wall of a target vessel 16 and anchor the implant in place, and a functional portion 18, configured to perform a beneficial medical function (FIG. 1E). If, for example, implant 12 is an embolic protection device then functional portion 18 resembles the shape of a helix. The helix is implanted with its axis perpendicular to the blood flow in the vessel, and (sufficiently large) emboli originating upstream of the implant may be prevented by the helix coils from flowing past the implant. The helix of monofilament embolic protection devices according to some embodiments may be configured to trace the shape of a cone or an hour glass. Such devices may have a stem intended for traversing a vessel wall. The stem may be perpendicular to the helix axis.

(19) Needle 11 may be made from metal or plastic. Suitable metals include, for example, stainless steel and nitinol. The outer diameter of the needle may range from about 0.2 mm to 2 mm. The inner diameter of the needle may range from 0.1 mm to 1.9 mm.

(20) Whenever implant 12 is a monofilament implant, the inner diameter of needle 11 may be between one and two times the diameter of the wire from which implant 12 is made. We have found in laboratory experiments that this minimizes the push force required to insert and/or advance implant 12 in the lumen of needle 11.

(21) In operation, the operator first assesses the size of target vessel 16. Typically, the assessment is made by, for example, ultrasound, fluoroscopy, CT, or MRI. If, for example, the vessel is an artery or a vein, the systolic (minimal) diameter of the vessel at the implantation site is measured and recorded. The operator then chooses an appropriately sized implant 12 (preloaded in system 1). Whenever implant 12 is a monofilament implant, the operator chooses the implant size according to the following rule: the maximal diameter of the deployed state of the implant should be about 0.5 to 1.5 mm less than the systolic diameter of the vessel. In some embodiments under-sizing may be required in order to allow for the implant to properly exteriorize and assume its functional, deployed shape.

(22) Next, the operator punctures skin 15, advances the tip of needle 11 towards the target vessel 16, and punctures target vessel 16 using the tip of needle 11 (FIG. 1 B). All of these steps may be performed under imaging guidance. Possible imaging modalities include ultrasound, high resolution ultrasound, x-ray fluoroscopy, CT, and MRI. The tip is placed a predetermined distance from the vessel puncture site, and the needle assumes a predetermined orientation. For example, if implant 12 is an embolic protection device, then the tip of needle 11 is placed about 1 mm into the lumen of vessel 16. The needle assumes a perpendicular orientation with respect to a plane tangent to the arterial wall at the puncture site. Whenever the operator determines that either the tip is placed improperly or the needle orientation is improper, system 1 may be retracted and the present step of the procedure may be attempted again.

(23) Once proper needle position has been achieved, the operator holds needle 11 steady and advances pusher 10 towards the distal end of the needle (FIG. 1 C). This causes implant 12 to be exteriorized from the needle. The exteriorized portion of the implant attempts to assume its functional deployed shape.

(24) The operator continues to push pusher 10 until its proximal end touches the proximal end of needle 11. Whenever implant 12 comprises a stem 17 pusher 10 may be configured such that at the position described in FIG. 1D the distance between the distal tip of the pusher and the end of the needle is approximately equal to the length of the stem. In some embodiments, this enables the implant 12 to assume the correct orientation within the vessel.

(25) Next, the operator verifies using an appropriate imaging modality that the implant is properly positioned and withdraws the needle and the pusher out of the patient's body (FIG. 1E). The implantation procedure is complete.

(26) Reference is now made to FIGS. 2A-C, which depict various designs according to some embodiments of needle 11 of system 1. Needle 11 need not be of uniform outer diameter. Furthermore, needle 11 need not be of monoblock construction. For example, needle 11 may comprise a first larger diameter needle 21 and a second smaller diameter vessel-puncturing needle 22 (FIG. 2A). The second needle 22 is housed within the lumen of the first needle 21. The distal tip of second needle 22 protrudes a predetermined distance distally to the distal end of first needle 21. This distance is typically somewhat larger than the thickness of the target vessel wall. The two needles may be connected using a suitable means such as, for example, gluing, or welding. First needle 21 may have an outer diameter ranging from about 0.3 mm to about 1 mm, and second needle 22 may have an outer diameter ranging from about 0.1 mm to about 0.8 mm. First needle 21 may be made out of metal, such as, for example, stainless steel or nitinol. The same goes for second needle 22.

(27) In operation, the operator may use ultrasound guidance to advance the needle of FIG. 2A towards the target vessel. As the first needle 21 is clearly visible (whereas the tip of second needle 22 need not be ultrasound visible), the operator punctures the vessel wall by advancing the tip of the first needle adjacent to the vessel wall. The second needle 22, whose sharp distal end protrudes beyond the distal end of first needle 21, thus penetrates the vessel wall.

(28) The embodiment of needle 11 depicted in FIG. 2A has the following advantages: (I) safety: the second needle may have a very small outer diameter, thereby causing minimal reducing trauma to the vessel wall. For example, the outer diameter of second needle 22 may be less than 0.5 mm, or even less than 0.3 mm. (2) The first needle may have a diameter sufficient to render it highly visible under ultrasound guidance. For example, the diameter of the first needle 21 may be greater than 0.5 mm, or even greater than 0.8 mm; (3) The first needle 21 may have an outer diameter sufficiently large as to make needle 11 sufficiently stiff to penetrate towards structures deep in the patient's body. Thus, the embodiment of needle 11 according to FIG. 2A eliminates the inherent tradeoff existing in uniform-outer-diameter needles: ultrasound visibility and stiffness on the one hand against a small outer diameter facilitating minimally-traumatic punctures.

(29) Reference is now made to FIGS. 2B and 2C, which depict some embodiments of needle 11 according to the present disclosure. In both cases the outer diameter of the distal end of the needle is smaller than the outer diameter of the proximal end of the needle. In FIG. 2B the transition from the smaller to the larger outer diameter is continuous, whereas in FIG. 2C it is discontinuous (that is, a step or a multi-step transition). The operation of systems I comprising the needles 11 according to FIGS. 2B and 2C is similar to the operation of systems based on the needle of FIG. 2A, and will therefore be omitted. The advantages of the needles II according to FIGS. 2B and 2C are also essentially the same as for the needle of FIG. 2A. The needles of FIG. 2B-C may be made out of metal, such as, for example, stainless steel or nitinol. The needles may be given their shapes by, for example, machining.

(30) The needles of FIGS. 2A-C may be made echogenic by roughening their surfaces, providing them with ultrasound reflection enhancement means, such as cornerstone reflectors, or coating them with echogenic coatings such as a micro-bubble-containing polymer coating.

(31) Reference is now made to FIGS. 3A-F, which depict an implant system and a method for implant delivery according to some embodiments of the present disclosure. System 3 may comprise an implant 12, a first echogenic needle 35, a second needle 36, and a pusher 31.

(32) Implant 12, which may (but does not have to be) a monofilament implant, is substantially similar to the implant of system 1, and therefore its detailed description will be omitted here.

(33) Second needle 36 may be made, for example, from plastic or metal. Suitable metals include, for example, stainless steel and nitinol. The outer diameter of second needle may be less than about 0.5 mm, or even less than about 0.3 mm. The inner diameter of second needle may be less than about 0.4 mm, or even less than 0.25 mm. Optionally, a needle stabilizing tube 38 may be configured to receive first needle 35 in its lumen. Tube 38 may be rigidly joined to second needle 36 at a predetermined point along the length of second needle 36. Optionally, a handle 37 may be disposed and rigidly connected to second needle 36 at the vicinity of the point where needle 36 and tube 38 are joined.

(34) First needle 35 may be made, for example, from plastic or metal. Suitable metals include, for example, stainless steel and nitinol. The outer diameter of first needle 35 may range from about 0.2 mm to about 1 mm.

(35) Pusher 31 may have a similar construction to pusher 13 of system 1: pusher 13 may comprise a push wire 34 and optionally a pusher stabilizing tube 33, which may be joined at their proximal ends. Optionally, pusher 31 may comprise a pusher handle 32.

(36) Initially (FIG. 3A), implant 12 situated in the un-deployed state near the distal end of the lumen of second needle 36. Push wire 34 is slidably received in the proximal end of the lumen of second needle 36. Stabilizing pusher tube 33 slidably receives at its distal end the proximal end of second needle 36. Second needle 36 is slidably received in the proximal end of the lumen of first needle 35. Needle stabilizing tube 38 slidably receives the proximal end of first needle 35. Initially, the distal tip of second needle 36 is within the lumen of first needle 35.

(37) In operation, the operator first assesses the size of target vessel 16. Typically, the assessment is made by, for example, ultrasound, fluoroscopy, CT, or MM. If, for example, whenever the vessel is an artery or a vein, the systolic (minimal) diameter of the vessel at the implantation site is measured and recorded. The operator then chooses an appropriately sized implant 12 (preloaded in system 3). Whenever implant 12 is a monofilament implant the operator may choose the size according to the following rule: the maximal diameter of the deployed state of the implant should be about 0.5 to 1 mm less than the systolic diameter of the vessel. Undersizing is required in order to allow for the implant to properly exteriorize and assume its functional, deployed shape.

(38) Next, the operator punctures skin 15 using the tip of first needle 35 and advances the tip of needle 35 towards the target vessel 16 (FIG. 3B). All of these steps may be performed under imaging guidance. Possible imaging modalities include ultrasound, high resolution ultrasound, x-ray fluoroscopy, CT, and Mill. The tip of first needle 35 is placed a predetermined distance from the vessel puncture site, and the needle assumes a predetermined orientation. For example, if implant 12 is an embolic protection device, then the tip of needle 35 is placed about 1 mm outside of the wall of vessel 16. The needle assumes a perpendicular orientation with respect to a plane tangent to the arterial wall at the puncture site. Whenever the operator determines that either the tip is placed improperly or the needle orientation is improper, system 3 may be retracted and the present step of the procedure may be attempted again.

(39) Once proper needle position has been achieved, the operator holds needle 35 steady and advances handle 37 towards the distal end of needle 35 (FIG. 3C). This causes second needle 36 to exteriorize from the lumen of first needle 35 and puncture the vessel wall. The pushing of handle 37 ceases when the proximal end of first needle 35 reaches handle 37 (and, optionally, the proximal end of stabilizing tube 38, which prevents the bucking of needle 36).

(40) Next, the operator holds needles 35 and 36 steady and advances pusher 31 towards the distal end of needle 36 (FIG. 3D). This causes implant 12 to be exteriorized from the needle. The exteriorized portion of the needle attempts to assume its functional shape.

(41) The operator continues to push pusher 31 until its proximal end touches the proximal end of second needle 36. Whenever implant 12 comprises a stem 17 pusher 31 may be configured such that at the position depicted in FIG. 3E the distance between the distal tip of the push wire 34 and the end of needle 36 is approximately equal to the length of the stem. This enables the implant 12 to assume the correct orientation within the vessel.

(42) Next, the operator verifies using an appropriate imaging modality that the implant is properly positioned and withdraws the needles and the pusher out of the patient's body (FIG. 3F). The implantation procedure is complete.

(43) An embodiment of system 3 lacking implant 12 and in which second needle 36 is configured as a biopsy needle is possible.

(44) System 3 has the following important advantages: (1) ease of use: initially, the tip of the second needle is inside the lumen of the first needle. Therefore confusion between the tips of the two needles upon ultrasound visualization is eliminated; (2) safety: the second needle may have a very small outer diameter, thereby making the puncture in the vessel wall correspondingly small and non-traumatic; (3) the needle-in-needle configuration provides desired stiffness during system insertion.

(45) Reference is now made to FIGS. 4A-E, which depict an implant system according to some embodiments of the present disclosure. System 4 may comprise an implant 12, implant manipulation means 40, and a needle 43.

(46) Implant 12, which may (but does not have to) be a monofilament implant, is substantially similar to the implant of systems 1 and 3. Needle 43 may be substantially similar to needle 11 of system 1. Therefore a detailed description of implant 12 and needle 43 is omitted.

(47) Implant manipulation means 40 may comprise a pusher 41, a connector 42, and a stopper 44.

(48) Pusher 41 may be substantially similar to pusher 10 or to push wire 14 of system 1.

(49) Connector 42 may be configured as a tube having a lumen, whose function is to provide a rigid yet severable connection between implant 12 and pusher 41. The connector may be made, for example, from metal, plastic, or heat-shrinkable plastic.

(50) Stopper 44 may be a tube disposed near the distal end of the lumen of needle 43. The lumen of stopper 44 may be of uniform diameter, or it might have a varying diameter. The lumen of stopper 44 may have the shape of a cone with the apex cut off. Stopper 44 may be made from metal. The stopper may be rigidly connected to the needle by, for example, welding, soldering, or brazing. Stopper 44 may be integral with needle 43. Whenever the stopper is integral with the needle it may be made by, for example, machining the needle.

(51) Connector 42 may be configured to receive at its distal end the proximal end of implant 12. Connector 42 may also be configured to receive at its proximal end the distal end of pusher 41. The connector may be configured to rigidly engage both the proximal part of implant 12 and the distal part of pusher 41 by static friction. The static friction force may be configured sufficiently large such that pulling the implant into the needle (by pulling the pusher) is possible without severing the connection made by connector 42 between implant 12 and pusher 41. The static friction force may also be simultaneously configured to be sufficiently small as to enable the pusher and implant to slide through the lumen of the connector when sufficient push-force is applied to the pusher and the connector is kept motionless.

(52) Providing appropriate static friction force may be achieved by one or more of making the connector from heat-shrinkable plastic and optimizing the connector's length, initial luminal diameter, and wall thickness.

(53) Both pusher 41 and engagement mechanism 42 may be configured to be slidably received within the lumen of needle 43. Implant 12 is configured to be slidably received in its un-deployed state within the distal end of the lumen of needle 43.

(54) Implant 12 is exteriorized by sliding pusher 41 within the lumen of needle 43 until the distal end of connector 42 is in contact with the proximal end of stopper 44 (FIG. 4B). The connector is thus prevented from further advancing distally in the lumen of needle 43. When the implant is in the position depicted in FIG. 4B, it is possible to exteriorize the implant completely by continuing to push the pusher. The continued pushing causes the pusher to slide within the lumen of connector 42, thereby overcoming the friction force between connector 42 and implant 12, thus pushing the proximal part of implant 12 out of the lumen of the connector (FIG. 40). Needle 43 and manipulation means 40 may then be retracted, leaving behind implant 12 in the deployed state (FIG. 4E).

(55) It is also possible interiorize a partially exteriorized implant 12 by pulling the pusher with respect to needle 43. The pull force is transmitted to implant 12 via the static friction force between connector 42 and both of implant 12 and pusher 41 (FIG. 4C).

(56) The operation of system 4 is substantially similar to the operation of system 1, except for the following step. Following near-complete exteriorization (FIG. 4B) of the implant from the needle, the operator verifies using a suitable imaging modality that the implant is properly deployed in the target vessel. If this is the case then the operator continues to push the pusher while holding the needle in place, thereby releasing the implant from the connector (FIG. 40) and withdraws from the patient's body all non-implantable elements of the system (FIG. 4E). Otherwise, the operator holds needle 43 steady and pulls pusher 41 back, thereby interiorizing implant 12 into the needle lumen. The operator may then attempt the procedure once more.

(57) It is possible for connector 42 to engage implant 12 and/or pusher 41 by any mechanical means known in the art. Suitable mechanical means may include, screwing, a bayonet, and a positive locking mechanism. It is possible to make the pusher from an electricity conducting core and an insulating coating. The connector may also be made from an insulator. A nick may be made in the insulating coating of the pusher. Electric current may be run in the core, thereby electrolyzing the conductor in the vicinity of the nick. This mechanism, similar to the detachment mechanism of embolization coils, may be used to detach the implant and the connector from the pusher.

(58) In some embodiments, stopper 44 may be optional.

(59) Reference is now made to FIGS. 5A-D, which depict an implant system according to some embodiments of the present disclosure. System 5 may comprise an implant 12, an implant manipulation means 51, a needle 56, and a stopper 54.

(60) Implant 12, which may (but does not have to) be a monofilament implant, may be substantially similar to the implant of systems 1 and 3. Needle 56 may be substantially similar to needle 11 of system 1. Therefore a detailed description of implant 12 and needle 56 is omitted.

(61) Implant manipulation means 51 may comprise a push tube 52, a disengagement wire 53, and, optionally, wire handle 55. Disengagement wire is configured to be slidably received thin (the proximal end of) the lumen of push tube 52.

(62) Implant manipulation means 51 is configured to be slidably received within the proximal end of the lumen of needle 56. Implant 12 is configured to be slidably received in its un-deployed state within the distal end of the lumen of needle 56.

(63) The distal end of push tube 52 mechanically engages the proximal end of implant 12: the proximal end of implant 12 is inserted in the distal end of the lumen of push tube 52. The connection is held together by static friction.

(64) Implant 12 is exteriorized by sliding implant manipulation means 51 within the lumen of needle 56 (FIG. 5B). It is also possible interiorize a partially exteriorized implant 12 by pulling the manipulation means with respect to needle 56.

(65) Implant 12 may be disengaged from implant manipulation means 51 in the following way: The stopper 54 is pushed distally until it contacts the proximal end of needle 56. This causes the disengagement wire to be pushed distally, thereby exteriorizing the proximal end of implant 12 from the distal end of the lumen of push tube 52.

(66) The operation of system 5 is substantially similar to the operation of system 1, except for the following step. Following near-complete exteriorization of the implant from the needle, wherein the proximal end of implant 12 is engaged with the distal end of push tube 52 and the stopper 54 is in contact with the proximal end of needle 56 (FIG. 5B), the operator verifies using a suitable imaging modality that the implant is properly deployed in the target vessel. If this is the case then the operator pushes the disengagement wire handle distally and thereby disengages the implant from the push tube (FIG. 5C). Then the operator withdraws from the patient's body all non-implantable elements of the system. Otherwise, the operator holds needle 56 steady and pulls pusher 51 back, thereby interiorizing implant 12 into the needle lumen. The operator may then attempt the procedure once more.

(67) The systems according to the embodiment presented in FIGS. 4A-E and 5A-D have the advantage of improved safety: an improperly exteriorized implant may be withdrawn back into the needle, thereby obviating the need to extract a mal-deployed implant using minimally invasive or even surgical means.

(68) Reference is now made to FIGS. 6A-C, which depict an automatic implant system according to some embodiments of the present disclosure. Automatic implant system 6 may comprise an implant 12, a driving mechanism 61, a pusher 64, and a needle 68. Implant 12, which may (but does not have to) be a monofilament implant, may be substantially similar to the implant of systems 1 and 3. Needle 68 may be substantially similar to needle 11 of system 1. Therefore a detailed description of implant 12 and needle 68 is omitted.

(69) Pusher 64 may comprise push wire 65, stabilizing tube 67, and rack 66. Push wire 65 is substantially similar to push wire 14 of system 1, and stabilizing tube 67 is substantially similar to stabilizing tube 13 of system 1. The push wire and the stabilizing tube may be rigidly joined at their proximal end using a suitable joining technique (for example, gluing, welding, or soldering). Rack 66 is joined to stabilizing tube 65 on its outside wall. Rack 66 may be collinear with stabilizing tube 65 as in FIG. 6A. The rack may assume the shape of a toothed strip. It may also be cylindrically symmetrical. The rack may be integral with the stabilizing tube, or it may be separate from it.

(70) Driving mechanism 61 may comprise a motor 62 and a spur gear 63, which is rotated by the motor axis. The motor axis is substantially perpendicular to the needle. Driving mechanism 61 may be rigidly joined to needle 68. Driving mechanism 61 may also comprise one or more of a controller, a CPU, a computer memory, a man-machine interface, and a power supply (all not shown).

(71) Initially, implant 12 is loaded in its un-deployed shape in the distal lumen of needle 68. Push wire 65 of pusher 64 is slidably received in the proximal end of the lumen of needle 68. The distal end of stabilizing tube 67 slidably receives the proximal end of needle 68. Rack 66 is configured to engage with spur gear 63 via interlocking of the teeth of the rack with the teeth of the spur wheel. Thus, rotation of the spur wheel causes pusher 64 to move relative to needle 68.

(72) The operation of system 6 is substantially similar to the operation of system 1 except for the following difference: instead of manually pushing the pusher in order to exteriorize implant 12 from needle 68, the operator causes pusher 66 to exteriorize the implant by providing instructions (via, for example, buttons comprised in the man machine interface) to driving mechanism 61.

(73) System 6 has the following important advantages: (1) it enables single″handed operation by a single operator, and; (2) In reduces inter-operator variability because of automation.

(74) Reference is now made to FIGS. 7A-C, which depict an automatic implant system according to some embodiments of the present disclosure. Automatic implant system 7 may comprise an implant 12, a driving mechanism 71, a pusher 75, and a needle 79.

(75) Implant 12, which may (but does not have to) be a monofilament implant, may be substantially similar to the implant of systems 1 and 3. Needle 79 may be substantially similar to needle 11 of system 1. Therefore the detailed description of implant 12 and needle 79 is omitted.

(76) Pusher 75 is substantially similar to pusher 64 of system 6. Push wire 77, stabilizing tube 78, and rack 76 may be substantially similar to their counterpalis 65, 67, and 66 in pusher 64. Therefore a detailed description of pusher 75 is omitted.

(77) Driving mechanism 71 may comprise a motor 72 and a worm 74 having helical threads configured to engage the teeth of rack 76. The worm's rotation axis is identical with the motor axis. The motor axis is substantially parallel to the needle. Driving mechanism 71 is joined rigidly to needle 79. Driving mechanism 71 may also comprise one or more of a controller, a CPU, a computer memory, a man-machine interface, and a power supply (all not shown).

(78) Initially, implant 12 is loaded in its un-deployed shape in the distal lumen of needle 79. Push wire 77 of pusher 75 is slidably received in the proximal end of the lumen of needle 79. The distal end of stabilizing tube 78 slidably receives the proximal end of needle 79. Rack 76 is configured to engage with worm 73 via interlocking of the teeth of the rack with the threads of the worm. Thus, rotation of the worm causes pusher 75 to move relative to needle 79.

(79) The operation of system 7 is substantially similar to the operation of system 6.

(80) System 7 has the following important advantages: (1) It enables single-handed operation by a single operator; (2) In reduces inter-operator variability because of automation, and; (3) the parallel orientation of the motor axis and the needle makes for good ergonomic design.

(81) Reference is now made to FIGS. 8A-C, which depict an automatic implant system according to some embodiments of the present disclosure. Automatic implant system 8 may comprise a monofilament implant 12, a driving mechanism 80, a push wire 84, and a needle 85.

(82) Implant 12, which may (but does not have to) be a monofilament implant, may be substantially similar to the implant of systems 1 and 3. Needle 85 may be substantially similar to needle 11 of system 1. Therefore the detailed description of implant 12 and needle 85 is omitted.

(83) Push wire 84 is substantially similar to push wire 14 of system 1. Therefore a detailed description of push wire 14 is omitted.

(84) Driving mechanism 80 may comprise a motor 81 coupled to a first roller 82 and a second roller 83. Motor 81 causes roller 81 to rotate. Push wire 84 is disposed between the first and the second roller. The force of friction between the first roller and the push wire causes the push wire to advance or retract as a result of roller rotation by the motor.

(85) Driving mechanism 80 is joined rigidly to needle 85. Driving mechanism 80 may comprise one or more of a controller, a CPU, a computer memory, a man-machine interface, and a power supply (all not shown).

(86) Initially, implant 12 is loaded in its un-deployed shape in the distal lumen of needle 85. Push wire 84 is slidably received in the proximal end of the lumen of needle 85. Push wire 84 may initially have a substantially linear configuration, or it may have a more spatially compact form. For example, push wire 84 may initially be rolled on a spool (not shown) in order to save space in system 8.

(87) The operation of system 8 is substantially similar to the operation of system 6.

(88) System 8 has the following advantages: (1) it enables single-handed operation by a single operator; (2) In reduces inter-operator variability because of automation, and; (3) It is conductive towards an ergonomic, compact design because the push wire may be initially disposed on a spool or in a coil.

(89) Reference is now made to FIGS. 9A-H, which depict a removable implant system and method for implant delivery and potential removal according to some embodiments of the present disclosure.

(90) System 9 may comprise a pusher 90, a removable implant 91, and a needle 92. Pusher 90 may be a hollow tube having a lumen 97 therethrough. Pusher 90 may be made from, for example, a metal such as stainless steel, or from plastic.

(91) Removable implant 91 may comprise a monofilament 93, an anchor 94 (optional), and a pull-wire 98. Monofilament 93 and pull-wire 98 may be one and the same, or alternatively, monofilament 93 and pull-wire 98 may be separate components. The proximal end of monofilament 93 may be joined to the distal end of pull-wire 98 by any suitable method known in the art, such as welding, brazing, gluing, or by means of a mechanical connector. Monofilament 93 and pull-wire 98 may each be joined to anchor 94 by, for example, welding, brazing, gluing, or crimping.

(92) Monofilament 93 may be made from a super-elastic alloy, such as nitinol, and may be made from a wire having a circular cross-section, with a diameter between about 0.05 mm and about 1.0 mm (for example). Monofilament 93 may assume an un-deployed, substantially linear state (as in FIG. 9A) or a deployed, functional state (as in FIG. 9E). The monofilament is constrained to its un-deployed, substantially linear state by the needle, where the monofilament initially resides in the distal lumen end thereof. Upon exteriorization from the needle (FIGS. C, D), the monofilament retains its deployed, functional state by virtue of its super-elasticity.

(93) Implant 91 may have the same uses as implant 12 and may have any functional, deployed shape realizable by twisting monofilament 93. Monofilament 93 may have, but is not limited to have, a functional shape similar to that of any of the implants described in the PCT publications incorporated by reference herein (see paragraph [0046]).

(94) In some embodiments, the functional, deployed state of implant 91 may comprise a substantially straight stem 95, configured to traverse the wall of a target vessel 16 and secure the implant in place, and a functional portion 96, configured to perform a beneficial medical function. If, for example, implant 91 is an embolic protection device, then functional portion 96 resembles the shape of a helix. The helix may trace a shape similar to a shell of a body of revolution, such as, for example, a sphere, an oval, or an ellipsoid. The helix is implanted with its axis approximately perpendicular to the direction of the vessel (which, in arteries, for example, is the same as the direction of the blood flow). Thus, sufficiently large emboli originating upstream of the implant may be prevented by the helix coils from flowing past the implant.

(95) The length of the helix may be greater than the diameter of the vessel, thereby ensuring contact between the distal end of the helix and the vessel wall as the helix is compressed along the direction of its axis. Growth of cells from the vessel wall (neointimal formation) on the distal end of the helix may further secure implant 91 in place. The diameter of the helix may be less than the diameter of the vessel, thereby ensuring proper deployment.

(96) Anchor 94 may reside near the proximal end of stem 95. Anchor 94 may have, for example, an un-deployed state configured to fit within the lumen of needle 92, and a deployed state configured to adhere to surrounding tissue. Anchor 94 may be made from nitinol. The anchor may comprise, for example, one or more barb, one or more protrusion, or one or more micro-barb.

(97) Pull-wire 98 may have a circular cross section. The diameter of pull-wire 98 may be between 0.03 mm and 1.0 mm. Pull-wire 98 may be made, for example, of metal, a super-elastic alloy (nitinol), a polymer, or a biodegradable polymer.

(98) Needle 92 may be made from metal or plastic, with suitable metals including, for example, stainless steel and nitinol. The outer diameter of the needle may range from about 0.2 mm to about 2 mm. The inner diameter of the needle may range from 0.1 mm to 1.9 mm.

(99) Pull-wire 98 may be configured such that at least a portion of it slidably fits within lumen 97 of pusher 90. Pusher 90 may be configured to slidably fit within the lumen of needle 92. Pusher 90 may also be configured to push either on the proximal end of monofilament 93 or on the proximal end of anchor 94. Pusher 90 is initially arranged in the proximal end of the lumen of needle 92, proximally to monofilament 93 and anchor 94, with at least a portion of pull-wire 98 within pusher lumen 97.

(100) In operation, the operator first assesses the size of target vessel 16. Typically, the assessment is made by, for example, ultrasound, fluoroscopy, CT, or Mill. If, for example, the vessel is an artery or a vein, the systolic (minimal) diameter at the implantation site is measured and recorded. The operator then chooses an appropriately sized implant 91 (preloaded in system 9). If, for example, the functional portion of monofilament 93 is a helix, then the helix diameter may be chosen undersized between 0.1 mm and 1.0 mm compared to the minimal vessel diameter at the implantation site.

(101) Next, the operator punctures skin 15, advances the tip of needle 92 towards the target vessel 16, and punctures vessel 16 using the tip of needle 92 (FIG. 9B). All of these steps may be performed under imaging guidance. Possible imaging modalities include ultrasound, high resolution ultrasound, z-ray fluoroscopy, CT, and MM. The tip is placed in the lumen of the vessel, approximately in the middle of the lumen of the vessel. The needle may assume an approximately perpendicular orientation with respect to a plane tangent to the vessel wall at the puncture site.

(102) Once proper needle position in the vessel lumen has been achieved, the operator advance pusher 90 towards the distal end of needle 92 while holding the needle steady (FIG. 9C). This causes implant 91 to be exteriorized from the needle. The exteriorized portion of the implant attempts to resume its functional deployed shape.

(103) The operator continues to push pusher 90 until its proximal end is aligned with the proximal end of the needle. Whenever implant 91 comprises a stem 95 and an anchor 94 pusher 90 may be configured such that at the position described in FIG. 9D the distance between the distal end of the pusher and the tip of the needle is approximately equal to the length of the stem. In some embodiments, this enables monofilament 93 to assume the correct orientation within the vessel.

(104) Next, the operator verifies using a proper imaging modality that the monofilament has correctly assumed its functional shape within the vessel lumen. The operator then withdraws the needle and the pusher. The anchor slides out of the tip of the needle as the needle is being pulled, and the pull-wire 98 slides out of pusher lumen 97. The situation depicted in FIG. 9E is achieved upon complete withdrawal of the needle and the pusher: functional portion 96 of monofilament 93 is within the lumen of vessel 16, stem 95 traverses the vessel wall, anchor 94 is external to the vessel wall and under skin 15, and pull-wire 98 traverses the patient's skin.

(105) Whenever implant 91 is intended for permanent use, the operator inspects the implantation site using a suitable imaging modality, such as ultrasound, x-ray, fluoroscopy, MRI or CT, anywhere from, for example, minutes to months after the implantation. If the result is satisfactory, the operator clips pull-wire 98 at the level of skin 15 and lifts the skin, thereby placing the entire remainder of the pull-wire subcutaneously. The situation depicted in FIG. 9F is achieved.

(106) Whenever implant 91 is intended for removal due to the temporary nature of its use, or whenever implant 91 is intended for permanent use but has to be removed due to safety reasons, the operator pulls the pull wire, thereby causing monofilament 93 to deform as in FIG. 9G and be exteriorized from vessel 16 and from the patient's body (FIG. 9H). Monofilament 93 may exit the vessel wall through the breach in which the stem originally resides.

(107) Note that an automatic system having a hollow pusher may be used to deliver implant 91. Operation is similar to that described above for system 9 (except that a motor is used to advance the pusher via a gear and a rack), and therefore detailed description is omitted.

(108) Any and all combinations of the embodiments described herein may be possible. For example automatic systems in which the implant may be retrieved back into the needle are possible.

(109) Example embodiments have been described herein. As may be noted elsewhere, these embodiments have been described for illustrative purposes only and are not limiting. Other embodiments are possible and are covered by the disclosure, which will be apparent from the teachings contained herein. Thus, the breadth and scope of the disclosure should not be limited by any of the above-described embodiments but should be defined only in accordance with features and claims supported by the present disclosure and their equivalents. Moreover, embodiments of the subject disclosure may include formulations, methods, systems and devices which may further include any and all elements/features from any other disclosed formulations, methods, systems, and devices, including the manufacture and use thereof. In other words, features from one and/or another disclosed embodiment may be interchangeable with features from other disclosed embodiments, which, in turn, correspond to yet other embodiments. One or more features/elements of disclosed embodiments may be removed and still result in patentable subject matter (and thus, resulting in yet more embodiments of the subject disclosure). Furthermore, some embodiments of the present disclosure may be distinguishable from the prior art by specifically lacking one and/or another feature, functionality, ingredient or structure which is included in the prior art (i.e., claims directed to such embodiments may include “negative limitations”).

(110) Any and all references, articles, publications, patents, patent publications, and patent applications cited herein are incorporated by reference in their entireties for all purposes. However, mention of any reference, article, publication, patent, patent publication, and patent application cited herein is not, and should not be taken as, an acknowledgment or any form of suggestion that they constitute valid prior art or form part of the common general knowledge in any country in the world.