Implant delivery system

An implant delivery system comprises an elongate tubular member having a lumen, a tubular implant coaxially disposed within the lumen of the elongate tubular member, and a delivery assembly having a distal portion coaxially disposed within tubular implant. The delivery assembly comprises a delivery wire, an engaging bumper fixedly coupled to the delivery wire, a stopper bumper fixedly coupled to the delivery wire, and a floating element slidably coupled around the delivery wire and disposed between the bumpers, thereby limiting linear translation of the floating element therebetween. The floating element has an engaging portion configured to engage the engaging bumper when the delivery wire is axially translated relative to the elongate member in a first direction. The floating element is configured to radially expand outward to frictionally engage the implant when the engaging portion of the floating element engages the engaging bumper.

FIELD

The present disclosure relates generally to medical devices and intravascular medical procedures and, more particularly, to devices and methods for delivering an implant to a target site in a blood or other body vessel.

BACKGROUND

The use of intravascular medical devices has become an effective method for treating many types of vascular disease. In general, a suitable intravascular device is inserted into the vascular system of the patient and navigated through the vasculature to a desired target site. Using this method, virtually any target site in the patient's vascular system may be accessed, including the coronary, cerebral, and peripheral vasculature.

Medical implants, such as stents, stent grafts, flow-diverters, and vena cava filters, are often utilized in combination with a delivery device for placement at a desired location within the body. A medical implant, such as a stent, may be loaded into a stent delivery device and then introduced into the lumen of a body vessel in a configuration having a reduced diameter. Once delivered to a target location within the body, the stent may then be expanded to an enlarged configuration within the vessel to support and reinforce the vessel wall while maintaining the vessel in an open, unobstructed condition. The stent may be configured to be self-expanding, expanded by a stored potential radial force such as a balloon, or a combination of self-expanding and balloon expanded.

There is an ongoing need to provide alternative stent delivery devices that delivery medical implants into the vasculature of a patient.

SUMMARY

In accordance with a first embodiment of the disclosed inventions, an implant delivery system comprises an elongate tubular member having a lumen, a tubular implant coaxially disposed within the lumen of the elongate tubular member, and a delivery assembly having a distal portion coaxially disposed within tubular implant.

In accordance with one aspect of the disclosed inventions, the delivery assembly comprises a delivery wire, an engaging bumper fixedly coupled to the delivery wire, a stopper bumper fixedly coupled to the delivery wire, and a floating element slidably coupled around the delivery wire and disposed between the bumpers, thereby limiting linear translation of the floating element therebetween. The floating element has an engaging portion configured to engage the engaging bumper when the delivery wire is axially translated relative to the elongate member in a first direction, wherein the floating element is configured to radially expand (e.g., by flaring outward) to frictionally engage the implant when the engaging portion of the floating element engages the engaging bumper.

In one embodiment, the floating element comprises an annular portion slidably disposed around the delivery wire. The annular portion is configured to contact the stopper bumper when the delivery wire is axially translated relative to the elongate member in a second direction opposite to the first direction. The floating element is configured to maintain a radially unexpanded configuration in which the floating element does not frictionally engage the implant when the annular portion of the floating element contacts the stopper bumper. In various embodiments, the engaging portion of the floating element has an inner surface, and the engaging bumper has an outer surface that engages the inner surface of the floating element when the delivery wire is axially translated relative to the elongate member in the first direction. For example, the outer surface of the engaging bumper may taper inwards towards the engaging portion of the floating element.

In one embodiment, the annular portion of the floating element has an abutting surface and the stopper bumper has a corresponding abutting surface that abuts the abutting surface of the floating element when the delivery wire is axially translated relative to the elongate member in the second direction. In this case, the abutting surface of the stopper bumper may be substantially perpendicular to the second direction.

The engaging portion of the floating element may have one of a funnel-like, flower-like, and skirt-like configuration. For example, the engaging portion of the floating element may have a funnel-like configuration including an elastically compressible bent section disposed between two straight sections. The engaging portion of the floating element may have a flower-like configuration including a plurality of petal-like elements. The engaging portion of the floating element may have a flower-like configuration including a plurality of flaps.

In accordance with another embodiment of the disclosed inventions, a delivery assembly comprises a delivery wire, a first set of bumpers including a first engaging bumper and a first stopper bumper fixedly coupled to the delivery wire, a second set of bumpers including a second engaging bumper and a second stopper bumper fixedly coupled to the delivery wire, and a set of floating elements including a first floating element and a second floating element slidably coupled around the delivery wire.

The first floating element is disposed between the first engaging bumper and the first stopper bumper, thereby limiting linear translation of the first floating element therebetween. The first floating element has an engaging portion configured to engage the first engaging bumper when the delivery wire is axially translated in a first direction. The first floating element is configured to radially expand (e.g., by flaring outward) to frictionally engage the implant when the engaging portion of the first floating element engages the first engaging bumper.

The second floating element is disposed between the second engaging bumper and the second stopper bumper, thereby limiting linear translation of the second floating element therebetween. The second floating element has an engaging portion configured to engage the second engaging bumper when the delivery wire is axially translated relative to the elongate member in a second direction opposite the first direction. The second floating element is configured to radially expand (e.g., by flaring outward) to frictionally engage the implant when the engaging portion of the second floating element engages the second engaging bumper.

In one embodiment, the first floating element comprises an annular portion slidably disposed around the delivery wire. The annular portion is configured to contact the first stopper bumper when the delivery wire is axially translated relative to the elongate member in the second direction. The engaging portion of each of the first and second floating elements may have one of a funnel-like, flower-like, and skirt-like configuration. The first floating element is configured to maintain a non-radially expanded configuration in which the first floating element does not frictionally engage the implant when the annular portion of the first floating element contacts the first stopper bumper. The second floating element comprises an annular portion slidably disposed around the delivery wire. The annular portion is configured to contact the second stopper bumper when the delivery wire is axially translated relative to the elongate member in the first direction. The second floating element is configured to maintain a non-radially expanded configuration in which the second floating element does not frictionally engage the implant when the annular portion of the second floating element contacts the second stopper bumper.

In one such embodiment, the engaging portion of the first floating element has an inner surface and the first engaging bumper has a corresponding outer surface that tapers towards the engaging portion of the first floating element and engages the inner surface of the first floating element when the delivery wire is axially translated relative to the elongate member in the first direction, and the engaging portion of the second floating element has an inner surface and the second engaging bumper has a corresponding outer surface that tapers towards the engaging portion of the second floating element and that engages the inner surface of the second floating element when the delivery wire is axially translated relative to the elongate member in the second direction.

In one such embodiment, the annular portion of the first floating element has an abutting surface, and the first stopper bumper has an abutting surface perpendicular to the second direction that abuts the abutting surface of the first floating element when the delivery wire is axially translated relative to the elongate member in the second direction, and the annular portion of the second floating element has an abutting surface, and the second stopper bumper has an abutting surface perpendicular to the first direction that abuts the abutting surface of the second floating element when the delivery wire is axially translated relative to the elongate member in the first direction.

In accordance with a yet another embodiment, a method of operating the implant delivery system is provided, wherein the implant delivery system comprises an elongate tubular member having a lumen, a tubular implant coaxially disposed within the lumen of the elongate tubular member, and a delivery assembly having a distal portion coaxially disposed within tubular implant, and the delivery assembly comprises a delivery wire, a first engaging bumper fixedly coupled to the delivery wire, a first stopper bumper fixedly coupled to the delivery wire, and a first floating element slidably coupled around the delivery wire and disposed between the first bumpers, the method comprising axially translating the delivery wire relative to the elongate member in a first direction, while limiting linear translation of the first floating element between the first engaging bumper and the first stopper bumper, engaging the first engaging bumper with an engaging portion of the first floating element, such that the first floating element radially expands outward to frictionally engage the implant, and further axially translating the delivery wire relative to the elongate member in the first direction, thereby advancing the implant within the lumen of the elongate tubular member. The delivery wire may be further axially translated relative to the elongate member until the implant at least partially deploys out of the lumen of the elongate tubular member.

The deliver assembly may further comprise a second engaging bumper fixedly coupled to the delivery wire, a second stopper bumper fixedly coupled to the delivery wire, and a second floating element slidably coupled around the delivery wire and disposed between the second bumpers.

In this case, the method may further comprise axially translating the delivery wire relative to the elongate member in a second direction opposite to the first direction, while limiting linear translation of the second floating element between the second engaging bumper and the second stopper bumper, disengaging the first engaging bumper from the engaging portion of the first floating element, such that the first floating element radially contracts inwards to release the implant, engaging the second engaging bumper with an engaging portion of the second floating element, such that the second floating element radially expands outward to frictionally engage the implant, and continuing to axially translate the delivery wire relative to the elongate member in the second direction, thereby resheathing the implant within the lumen of the elongate tubular member.

Other and further aspects and features of embodiments of the disclosed inventions will become apparent from the ensuing detailed description in view of the accompanying figures.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Referring first toFIG. 1, one embodiment of an implant delivery system10constructed in accordance with one embodiment of the disclosed inventions will be described. The implant delivery system10generally comprises an elongate tubular member12, a tubular implant20(not shown inFIG. 1), and a delivery assembly30.

The elongate member12has a tubular configuration, and can, e.g., take the form of a sheath, catheter, micro-catheter or the like. The elongate member12has a proximal portion13, a distal portion16, and a lumen17extending through the elongate member12between the proximal portion13and the distal portion16. The proximal section13of the elongate member12remains outside of the patient and accessible to the operator when the implant delivery system10is in use, while the distal portion16of the elongate member12is sized and dimensioned to reach remote locations of a vasculature and is configured to deliver the implant20to a target location in a patient's body, such as an occlusion in a blood vessel, in a blood vessel adjacent to an aneurysm neck, a bifurcated blood vessel, or the like. The implant delivery system10has at least one fluid port15in fluid communication with the elongate member12, which is used to introduce fluids into the elongate member12. The implant20and delivery assembly30are disposed in the lumen17of the elongate member12of the implant delivery system10, as better appreciated inFIG. 2.

The implant20, such a stent or a flow diverter, includes a tubular resilient member having a proximal portion22, a distal portion24, and defining an inner lumen26extending therebetween (FIG. 2). The implant20has a delivery configuration when disposed within the lumen17of the elongate member12and/or is radially constrained by the elongate member12. The implant20is biased to expand radially outwards into a deployed configuration in which the implant20is expanded when deployed out of the elongate member12. The implant20may be constructed from a variety of materials such as stainless steel, elgiloy, nickel, titanium, nitinol, shape memory polymers, or combinations thereof. The implant20may also be formed in a variety of manners as well. For example, the implant20may be formed by etching or cutting a pattern from a tube or sheet of stent material; a sheet of stent material may be cut or etched according to a desired stent pattern whereupon the sheet may be rolled or otherwise formed into the desired substantially tubular, bifurcated or other shape. For the implant20, one or more wires or ribbons of stent material may be woven, braided or otherwise formed into a desired shape and pattern. The implant20may include further components that are welded, bonded or otherwise engaged to one another. The implant20may include a non-porous, non-permeable biocompatible material, cover or the like, when the implant20is used as a blood flow diverter.

The implant delivery system10may be used in an “over-the-wire” configuration, wherein the elongate member12is introduced into the patient over a guidewire which has been previously introduced, and the elongate member12extends over the entire length of the guidewire (not shown). Alternatively, the implant delivery system10may be used in a “rapid-exchange” configuration, where a guidewire extends through only a distal portion of the implant delivery system10from a guidewire port (not shown). In other alternative embodiments, the implant delivery system10may be introduced into the patient after a guidewire had been withdrawn leaving a sheath or access catheter distal portion at the target site for the assembly10to navigate through the vasculature of the patient within the sheath or access catheter.

The implant delivery system10may include one or more, or a plurality of regions along its length having different configurations and/or characteristics. For example, the distal portion16of the elongate member12may have an outer diameter less than the outer diameter of the proximal portion13to reduce the profile of the distal portion16and facilitate navigation in tortuous vasculature (FIG. 1). Furthermore, the distal portion16may be more flexible than the proximal portion13. Generally, the proximal portion13may be formed from material that is stiffer than the distal portion16of the elongate member12, so that the proximal portion13has sufficient pushability to advance through the patient's vascular system, while the distal portion16may be formed of a more flexible material so that the distal portion16may remain flexible and track more easily over a guidewire to access remote locations in tortuous regions of the vasculature. The elongate member12may be composed of suitable polymeric materials, metals and/or alloys, such as polyethylene, stainless steel or other suitable biocompatible materials or combinations thereof. In some instances, the proximal portion13may include a reinforcement layer, such a braided layer or coiled layer to enhance the pushability of the elongate member12. The elongate member12may include a transition region between the proximal portion13and the distal portion16.

Referring further toFIG. 2, the implant20is coaxially disposed within the distal portion16of elongate member12, and the delivery assembly30is coaxially disposed and axially movable relative to the elongate member12and the implant20. The delivery assembly30is configured to engage the implant20when the system30is axially translated relative to the elongate member12for delivery of the implant20into a target site of a patient. The interface between the delivery assembly30and the implant20will be described in further detail below.

The delivery assembly30comprises a delivery wire31having a proximal region32and a distal region33(FIG. 1). The delivery wire31may be made of a conventional guidewire, torqueable cable tube, a hypotube or the like. In either case, there are numerous materials that can be used for the delivery wire31to achieve the desired properties that are commonly associated with medical devices. Some examples can include metals, metal alloys, polymers, metal-polymer composites, and the like, or any other suitable material. For example, the delivery wire31may include nickel-titanium alloy, stainless steel, a composite of nickel-titanium alloy and stainless steel. In some cases, the delivery wire31can be made of the same material along its length, or in some embodiments, can include portions or sections made of different materials. In some embodiments, the material used to construct the delivery wire31is chosen to impart varying flexibility and stiffness characteristics to different portions of the delivery wire31. For example, the proximal region and the distal region33of the delivery wire31may be formed of different materials, such as materials having different moduli of elasticity, resulting in a difference in flexibility. For example, the proximal region32can be formed of stainless steel, and the distal region33can be formed of a nickel-titanium alloy. However, any suitable material or combination of material may be used for the delivery wire31, as desired.

The delivery wire31may further include a distal shapeable or pre-shaped atraumatic end34(FIG. 2), which may aid the advancement of the delivery wire31. In some embodiments, the distal end34may include a coil placed over a portion of a distal end of the delivery wire31(not shown) or, alternatively, may include a material melted down and placed over a portion of the distal end34of the delivery wire31. In some embodiments, the distal end34may include a radiopaque material to aid in visualization. Additionally, the distal end34of the delivery wire31may be floppy and steerable using pull wires (not shown) to facilitate tracking of the delivery assembly30through a vessel to reach a target site. Although not illustrated, it is contemplated that the distal end34of the delivery wire31may include one or more tapered sections, as desired.

The delivery wire31may optionally include one or more bands (not shown) in the distal region33of the delivery wire31. The bands may be formed integrally into the delivery wire31, or they may be separately formed from the delivery wire31and attached thereto. In some embodiments, the bands may be disposed on the delivery wire31. The bands may have a diameter greater than the diameter of the surrounding the delivery wire31. Bands may be formed of any suitable material, such as metals, metal alloys, polymers, metal-polymer composites, and the like, or any other suitable material, as well as any radiopaque material, as desired. Alternatively, it is contemplated that the delivery wire31may include one or more recesses instead of providing bands, if desired.

Significantly, the delivery assembly30comprises at least one set of bumpers40fixedly coupled to the delivery wire31, and a floating element50slidably coupled to the delivery wire31. In the embodiment ofFIG. 2, two sets of bumpers40(a first set of distal bumpers40′ and a second set of proximal bumpers40″) are disposed at the distal portion32of the delivery wire31, with each set having a respective floating element50′/50″ therebetween. In particular, the distal bumpers40′ include a distal engaging bumper42′ and a distal stopper bumper44′, with a distal floating element50′ therebetween, and the proximal bumpers40″ include a proximal engaging bumper42″ and a proximal stopper bumper44″, with a proximal floating element50″ therebetween. The engaging bumpers42/42′/42″ and the stopper bumpers44/44′/44″ are configured to limit translation of the respective floating elements50/50′/50″ therebetween. Additionally, the engaging bumpers42/42″/42″ are configured to interface with the respective floating elements50/50′/50″ to engage (i.e., frictionally engage) the implant20for delivery to a target site (FIGS. 3, 5A-D) and/or re-sheathing the implant20into the elongate member12(FIG. 4).

Each floating element50/50′/50″ has an annular portion51/51′/51″, such as a collar, ring or the like, and engaging portion52/52′/52″ having an inner surface53/53′/53″ configured to interface with an outer surface43/43′/43″ of the engaging bumper42/42′/42″ when the delivery assembly30is actuated, which is described in further detail below.

Between the distal set of bumpers40′, the engaging portion52′ of the distal floating element50′ is proximately disposed to the annular portion51′ of the distal floating element50′, such that the interface between the distal engaging bumper42′ and engaging portion52′ of the distal floating element50′ is configured to engage the implant20when the delivery wire31is advanced or translated in the distal direction for delivery of the implant20into the target site of the patient (FIG. 3).

In contrast, between the proximal set of bumpers40″, the engaging portion52″ of the proximal floating element50″ is distally disposed to the annular portion51of the proximal floating element50″, such that the interface between the proximal engaging bumper42″ and engaging portion52″ of the proximal floating element50″ is configured to engage the implant20when the delivery wire31is withdrawn or translated in the proximal direction for re-sheathing of the implant20into the elongate member12(FIG. 4).

As shown inFIG. 3, the delivery assembly30is actuated by advancing (i.e., distally translating, axially moving) the delivery wire31relative to the elongate member12. When the delivery wire31is advanced relative to the elongate member12, the distal engaging bumper42′ interfaces with the engaging portion52′ of the distal floating element50′, wherein the outer surface43′ of the engaging bumper42′ contacts the inner surface53′ of the engaging portion52′, so that the engaging portion52′ of the distal floating element50′ is disposed between the distal engaging bumper42′ and the implant20. The interface between the distal engaging bumper42′ and the engaging portion52′ of the distal floating element50′ exerts a radially outward force on an interior surface25of the implant20. This radially outward force is sufficient to contact and frictionally engage the implant20so as to advance and deliver the implant20to a target site when the delivery wire31advances relative to the elongate member12. Furthermore, when the delivery wire31is advanced relative to the elongate member12, the proximal stopper bumper44″ contacts the annular portion51″ of the proximal floating element50″, advancing and distally pushing the proximal floating element50″ along with the advancement of the delivery wire31. As shown inFIG. 3, the proximal floating element50″ does not frictionally engage the implant20during advancement of the delivery wire31.

As shown inFIG. 4, the delivery assembly30is actuated by withdrawing (i.e., proximately translating, axially moving) the delivery wire31relative to the elongate member12. When the delivery wire31is withdrawn relative to the elongate member12, the proximal engaging bumper42″ interfaces with the engaging portion52″ of the proximal floating element50″, wherein the outer surface43of the engaging bumper42″ contacts the inner surface53″ of the engaging portion52″, so that the engaging portion52″ of the proximal floating element50″ is disposed between the proximal engaging bumper42″ and the implant20. The interface between the proximal engaging bumper42″ and the engaging portion52of the proximal floating element50″ exerts a radially outward force on the interior surface25of the implant20. This radially outward force is sufficient to frictionally engage the implant20so as to withdraw and re-sheath the implant20when the delivery wire31is withdrawn relative to the elongate member12. Furthermore, when the delivery wire31is withdrawn relative to the elongate member12, the distal stopper bumper44′ contacts the annular portion51′ of the distal floating element50′, withdrawing and proximally pushing the distal floating element50′ along with the withdrawal of the delivery wire31. As shown inFIG. 4, the distal floating element50′ does not frictionally engage the implant20during withdrawal of the delivery wire31.

Thus, as can be appreciated, the delivery assembly30of the implant delivery system10comprises a bi-directional actuation. Particularly, as shown inFIG. 3, when the delivery wire31is axially translated relative to the elongate member12in a first direction (i.e., advanced in a distal direction), the implant20is engaged by the interface between the distal engaging bumper42′ and the engaging portion52′ of the distal floating element50′, while the proximal floating element50″ does not engage the implant20. Conversely, as shown inFIG. 4, when the delivery wire31is axially translated relative to the elongate member12in a second direction, opposite to the first direction (i.e., withdrawn in a proximal direction), the implant20is engaged by the interface between the proximal engaging bumper42″ and the engaging portion52″ of the proximal floating element50″, while the distal floating element50′ does not engage the implant20. The bi-directional delivery assembly30provides the operator of the implant delivery system10with the advantage of being able to both deliver or re-sheath the implant20by either advancing or withdrawing the delivery wire31relative to the elongate member12.

While the embodiment depicted inFIGS. 2-4comprises a delivery assembly30having two sets of bumpers40′ and40″, each having a respective floating member50′/50″, an alternative embodiment of the delivery assembly30may have more than two sets of bumpers40and floating members50. Still another embodiment of the delivery assembly30may comprise only one set of bumpers40with only one floating member50.

For example, as shown inFIGS. 5A-D, the delivery assembly30comprises one set of bumpers40and one floating element50for delivery of the implant20into the target site. The delivery assembly30is actuated by advancing (i.e., distally translating, axially moving) the delivery wire31relative to the elongate member12. When the delivery wire31is advanced relative to the elongate member12, the engaging bumper42approaches the floating element50(FIGS. 5A-B), and as the delivery wire31further advances, the outer surface43of the engaging bumper42interfaces with (i.e., contacts) the inner surface53the engaging portion52of the floating element50(FIG. 5C), so that the engaging portion52of the floating element50is disposed between the engaging bumper42and the implant20, frictionally engaging the implant20(FIG. 5D). As best seen inFIG. 5D, the interface between the engaging bumper42and the engaging portion52of the floating element50exerts a radially outward force (shown by arrows inFIG. 5D) on an interior surface25of the implant20. This radially outward force is sufficient to frictionally engage implant20so as to advance the implant within the elongate member12, and deliver the implant20to a target site when the delivery wire31advances relative to the elongate member12.

In the embodiments ofFIGS. 2-5D, each floating element50/50′/50″ is configured to radially expand outward (e.g., by flaring outward) to frictionally engage the implant20when the engaging portion52/52′/52″ of the floating element50/50′/50″ engages the respective engaging bumper42/42′/42″. In some embodiments, the engaging portion52/52′/52″ of the floating elements50/50′/50″ is dimensioned and sized to partially enter or occupy openings/cells in the implant20(FIG. 5D), thereby allowing further engagement and/or frictional forces between the delivery assembly30and the implant20. This design assists the axial displacement of the implant20relative to the elongate element12, further facilitating delivery or re-sheathing of the implant20.

In these embodiments and as best seen inFIG. 5C, the outer surface43of the engaging bumper42engages the inner surface53of the floating element50to radially expand the floating element50outwardly and frictionally contact and/or engage the implant20for translation relative to the elongate element12. To facilitate engagement between the engaging portion52of the floating element50and the respective engaging bumper42, and the consequential outward radial expansion of the floating element52, in the illustrated embodiments, the outer surface43of the engaging bumper42tapers inwards towards the engaging portion52of the respective floating element52. While the engaging bumpers42/42′/42″ depicted inFIGS. 2-5Dcomprise a disk-shape having a tapered annular portion, the engaging bumpers42/42′/42″ may include a variety of configurations having any cross-section, such as irregular shapes, as long as at least one cross-sectional dimension is suitable to interface with the inner surface53/53′/53″ of the engaging portion52/52′/52″ of the floating element50/50′/50″ and frictionally engage the implant20, as previously described.

In the embodiments ofFIGS. 2-5D, each floating element50/50′/50″ is configured to not radially expand outwardly (e.g., by not flaring outwardly), such that there is no frictional engagement with the implant20when the floating element50/50′/50″ engages the respective stopper bumper44/44′/44″. In these embodiments, the annular portion51/51′/51″ of each floating element50/50′/50″ has an abutting surface58/58′/58″, and the respective stopper bumper44/44′/44″ has an abutting surface48/48′/48″ that abuts the abutting surface58/58′/58″ of the floating element50/50′/50″ to axially displace the floating element50/50′/50″ relative to the implant20. To facilitate engagement between the floating element50/50′/50″ and the respective stopper bumper44/44′/44″, and the consequential axial displacement of the floating element50/50′/50″ relative to the implant20, the abutting surface58/58′/58″ of the annular portion51/51′/51″ of each floating element50/50′/50″ and the abutting surface48/48′/48″ of the stopper bumper44/44′/44″ are both perpendicular to the axial movement of the floating element50/50′/50″. While the stopper bumpers44/44′/44″ depicted inFIGS. 2-5Dcomprise a disk-shape configuration, and the stopper bumpers44/44′/44″ may comprise a variety of configuration, including irregular shapes, as long as at the stopper bumpers44/44′/44″ axially translates the floating element50/50′/50″ over the delivery wire31relative to the implant20, as previously described.

As depicted inFIGS. 2-5D, the engaging bumpers42/42′/42″ and the stopper bumpers44/44′/44″ have respective cross-sectional dimensions that are smaller than the inner diameter of the implant20in the delivery configuration, when the implant20is disposed within the lumen17of the elongate member12. In the embodiments ofFIGS. 2-4, the engaging bumpers42/42′/42″ have a cross-sectional dimension larger than the stopper bumpers44/44′/44″. In the embodiments ofFIGS. 5A-D, the engaging bumper42/42′/42″ has a cross-sectional dimension substantially similar to the stopper bumper44/44′/44″. It should be appreciated that variations of the relative dimensions of the engaging bumpers42/42′/42″ and the stopper bumpers44/44′/44″ may be suitable in some embodiments.

In the embodiments depicted inFIGS. 2-8B, the engaging portion52/52′/52″ extending from the annular portion51/51′/51″ of the floating element50/50′/50″ is composed of suitable biocompatible material configured to be elastically compressible, for instance, stainless steel, elgiloy, nickel, titanium, nitinol, shape memory polymers, or combinations thereof. There are numerous materials that can be used for floating element50/50′/50″ to achieve the desired properties for the interface of the engaging portion52/52′/52″ with the engaging bumper42/42′/42″ of the delivery assembly30. Some examples can include metals, metal alloys, polymers, metal-polymer composites, and the like, or any other suitable material. Examples of suitable metals and metal alloys can include stainless steel, nickel-titanium alloy such as a superelastic (i.e., pseudoelastic) or linear elastic nitinol; nickel-chromium alloy; nickel-chromium-iron alloy; cobalt alloy; tungsten or tungsten alloys; tantalum or tantalum alloys, gold or gold alloys, or the like; or other suitable metals, or combinations or alloys thereof. Examples of some suitable polymers can include, but are not limited to, polyoxymethylene (POM), polybutylene terephthalate (PBT), polyether block ester, polyether block amide (PEBA), fluorinated ethylene propylene (FEP), polyethylene (PE), polypropylene (PP), polyvinylchloride (PVC), polyurethane, polytetrafluoroethylene (PTFE), polyether-ether ketone (PEEK), polyimide, polyamide, polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polysufone, nylon, perfluoro(propyl vinyl ether) (PFA), polyether-ester, polymer/metal composites, or mixtures, blends or combinations thereof. Further, the engaging portion52/52′/52″ of the floating device50/50′/50″ may be formed by etching or cutting a pattern from a tube or sheet, or may be formed by one or more wires or ribbons of suitable materials woven, braided or otherwise formed into a desired shape and pattern. Further, the engaging bumpers42/42′/42″ and/or the stopper bumpers44/44′/44″ may be radiopaque, in which case they function as markers to facilitate determination of delivery wire31position.

The engaging portion52/52′/52″ of each floating element50/50′/50″ may have one of a funnel-like, flower-like, and skirt-like configuration. Various embodiments of the floating element50/50′/50″ are depicted inFIGS. 6-8. For example, with reference toFIG. 6, a floating element50acomprises a funnel-like configuration, where the engaging portion52includes a bent section55disposed between two straight sections54and56. The bent section55is configured to be elastically compressible, for instance, by heat-setting a stainless steel or shape memory alloy (e.g., nitinol). The engaging portion52extends from the annular portion51of the floating element50a, and is formed of suitable filaments or ribbons woven, braided or formed into a mesh. It should be appreciated that the engaging portion52of the floating element50amay be formed of a solid material, such as a liner, cover, or the like. Alternatively, the liner or cover may be permeable, porous, or includes apertures or perforations (not shown).

With reference toFIG. 7, a floating element50bcomprises a flower-like configuration, where the engaging portion52includes a plurality of petal-like elements52a-gextending from the annular portion51. The petal-like elements52a-gmay be formed by looped filaments57coupled to the annular portion51, where each of the looped filament57may have a respective braided cover59disposed therein. It should be appreciated that the petal-like elements52a-gof the engaging portion52of the floating element50bmay be formed by the looped filaments57without any braided cover disposed therein, or the petal-like elements52a-gmay be formed of a solid material, such as a liner, cover, or the like. Alternatively, the liner or cover may be permeable, porous, or includes apertures or perforations (not shown). The petal-like elements52a-gmay overlap with respective adjacently disposed petal-like elements, as shown inFIG. 7.

With reference toFIGS. 8A-8B, the engaging portion52of a floating element50ccomprises a plurality of flaps60having respective ends60′ coupled to or extending from the annular portion51. It should be appreciated that the plurality of flaps160of the engaging portion52of the floating element50cmay be permeable, porous, or includes apertures or perforations (not shown).

Having described the function and structure of the implant delivery system10, one method100of using the implant delivery system10illustrated inFIG. 2will now be discussed inFIG. 9. First, the implant delivery system10is introduced into the vasculature of a patient in a conventional manner, such that the distal portion16of the elongate member12is adjacent a target site within the vasculature of the patient (step102). Next, the delivery wire31is axially translated in the distal direction relative to the elongated member12, while limiting linear translation of the first (in this case the distal) floating element50′ between the first (in this case, the distal) engaging bumper42′ and the first (in this case, the distal) stopper bumper44′ (step104). Next, the distal engaging bumper42′ is engaged with the engaging portion52′ of the distal floating element50′, such that the distal floating element50′ radially expands outward to frictionally engage the implant20(step106). Then, the delivery wire31is further axially translated relative to the elongate member12in the distal direction, thereby advancing the implant20within the lumen17of the elongate member12(step108). The delivery wire31is axially translated relative to the elongate member12until the implant20at least partially deploys out of the lumen17of the elongate member12(step110).

If the implant20is only partially deployed, the implant20may be resheathed back into the elongate member20if it is decided that the deployment site of the implant20is not inaccurate. In particular, the delivery wire31is axially translated relative to the elongate member12in the proximal direction, while limiting linear translation of the second (in this case the proximal) floating element50″ between the second (in this case, the proximal) engaging bumper42″ and the second (in this case, the proximal) stopper bumper44″ (step112). The distal engaging bumper42′ is disengaged from the engaging portion52′ of the distal floating element50′, such that the distal floating element50′ radially contracts inwards to release the implant20(step114). Next, the proximal engaging bumper42″ is engaged with the engaging portion52of the proximal floating element50″, such that the proximal floating element50″ radially expands outward to frictionally engage the implant20(step116). Optionally, the delivery wire31is further axially translated relative to the elongate member12in the proximal direction, thereby resheathing the implant20within the lumen17of the elongate member12(step118). The distal portion16of the elongate member12can be repositioned (step120), and steps102-110, and if necessary steps112-118, can be repeated.

Although particular embodiments of the disclosed inventions have been shown and described herein, it will be understood by those skilled in the art that they are not intended to limit the disclosed inventions, and it will be obvious to those skilled in the art that various changes and modifications may be made (e.g., the dimensions of various parts). The specification and drawings are, accordingly, to be regarded in an illustrative rather than restrictive sense.