Patent Application
20070083219
The invention relates to embolic coil introducer sheath locking mechanisms, as well as related components, systems and methods.
Embolic coils can be used to occlude vessels in a variety of medical applications. In many instances, an embolic coil is contained in an introducer sheath. The introducer sheath containing the embolic coil is disposed within a body lumen (e.g., an artery) of a subject (e.g., a human), and the embolic coil is pushed out the distal end of the introducer sheath, using, for example, a pusher wire.
The invention relates to embolic coil introducer sheath locking mechanisms, as well as related components, systems and methods.
In a first aspect, systems are provided that include an embolic coil introducer sheath and a locking mechanism. The locking mechanism has a first position in which the locking mechanism applies pressure to the embolic coil introducer sheath and has a second position in which the locking mechanism does not apply pressure to the embolic coil introducer sheath. The locking mechanism is removable from the embolic coil introducer sheath.
In a second aspect, systems are provided that include an embolic coil introducer sheath and a locking mechanism having first and second positions. The locking mechanism applies pressure to the embolic coil introducer sheath when the locking mechanism is in the first position, and does not apply pressure to the embolic coil introducer sheath when the locking mechanism is in the second position. The locking mechanism can be moved from the second position to the first position.
In a third aspect, systems are provided that include an embolic coil introducer sheath and a locking mechanism having first and second positions. The locking mechanism applies pressure to the embolic coil introducer sheath when the locking mechanism is in the first position, and does not apply pressure to the embolic coil introducer sheath when the locking mechanism is in the second position. The locking mechanism can be repeatedly moved between the first and second positions.
In another aspect, systems are provided including an embolic coil introducer sheath and a clamp having first and second positions. The clamp applies pressure to the embolic coil introducer sheath when the clamp is in the first position, and the clamp does not apply pressure to the embolic coil introducer sheath when the clamp is in the second position.
In still another aspect, systems are provided including a resilient material having a bore, an embolic coil introducer sheath disposed in the bore of the resilient material, and a member configured to translate an axial force on the member into a radial compressive force on the embolic coil introducer sheath.
In yet another aspect, systems are provided having an embolic coil introducer sheath and a Touhy-Borst valve configured to apply pressure against the embolic coil introducer sheath.
In another aspect, systems are provided having an embolic coil introducer sheath, an embolic coil pusher wire, and a wedge configured to fit between the embolic coil introducer sheath and the embolic coil pusher wire.
In an additional aspect, systems are provided having an embolic coil introducer sheath and a sleeve comprising a polymer material and having at least one perforation. The sleeve is supported by the embolic coil introducer sheath.
In a further aspect, perforated embolic coil introducer sheaths are provided.
In still another aspect, systems are provided having an embolic coil pusher wire and an embolic coil introducer sheath having at least one perforation. The perforated embolic coil introducer sheath includes a locking portion that restricts longitudinal movement of the embolic coil pusher wire in the perforated embolic coil introducer sheath when the locking portion is in a first position and does not restrict longitudinal movement of the embolic coil pusher wire in the perforated embolic coil introducer sheath when the locking portion is in a second position.
Embodiments can include one or more of the following advantages.
In some embodiments, the locking mechanism can allow for easier control and/or use.
In some embodiments, the locking mechanisms may provide a relatively secure and/or reliable lock on the delivery wire.
In some embodiments, the locking mechanism may be repeatedly moved between a position in which the locking mechanism locks an embolic coil and a position in which the locking mechanism does not lock an embolic coil. This can, for example, allow for greater flexibility in delivering an embolic coil. As an example, the embolic coil can be locked in a first position, unlocked, moved to a second position and then relocked. In some embodiments, the locking mechanism retains substantially the same (e.g., full) degree of locking power of the locking mechanism (e.g., the locking power is substantially unchanged) upon being unlocked and subsequently relocked.
In some embodiments, the locking mechanism may be capable of being unlocked and removed and then repositioned and relocked.
In some embodiments, the locking mechanism may be capable of one-handed operation, that is to say, may be capable of being removed and/or replaced by an operator using only one hand.
Other features and advantages are apparent from the description, drawings and claims.
Like reference symbols in the various drawings indicate like elements.
In general, wedge-shaped locking mechanism 110 may be formed of a deformable material that can deform to fit the profile of the proximal end 108 of the introducer sheath 106 (see discussion above). Exemplary types of deformable materials include rubbers, synthetic rubbers, thermoplastic elastomers and foams. Examples of deformable materials include polyurethanes, Santoprenes™, low density polyethylene, silicone, polyisoprene, vinyl, polyvinyl chloride, ethylene vinyl acetate, and polypropylene. The wedge-shaped locking mechanism may be in the form of a deformable structure, which itself may be formed of a deformable material or a material that is not deformable. Exemplary deformable structures include braided, knit or woven metallic or polymeric structures. Combinations of materials can be used.
Embodiments of a wedge-shaped locking mechanism may include more than one slot (e.g., two or more slots, three or more slots, four or more slots, five or more slots). In embodiments that include more than one slot, different slots may extend the same length or different lengths. For example, one slot may extend the entire length of the wedge-shaped locking mechanism, enabling the locking mechanism to be opened and slipped off of the delivery wire and/or introducer sheath without necessitating sliding it off of the proximal end of the delivery wire. Similarly, such an embodiment may be reinstalled over the delivery wire without need to slide it the length of the delivery wire.
In certain embodiments, a wedge-shaped locking mechanism may be configured to lock the delivery wire in the introducer sheath without having any slots. For example, in such embodiments, the introducer sheath may be tapered or flared at its proximal end to further enable the formation of a snug fit with the wedge-shaped locking mechanism.
In general, the clamp 141 can be formed of a material capable of flexing to at least some degree to enable the clamp to be clamped around the sheath and to permit clamp to be unclamped and removed. Exemplary materials from which clamp 141 can be formed include plastics and metals. Examples of plastics include acrylonitrile butadiene styrene copolymer (ABS), polyvinyl chloride (PVC), low density polyethylene (LDPE), high density polyethylene, polypropylene, polyethylene, high density polypropylene, polyethylene terephthalate, nylon, silicone, vinyl, acrylic, polycarbonate and polyacetal (e.g., Delrin®). Examples of metals include stainless steel, Nitinol (NiTi), aluminum, titanium, cobalt-chromium alloys, and Elgiloy®.
Another embodiment of an embolic coil introducer system is illustrated in
In some embodiments, the locking mechanism is a device that translates axial force into radial compressive force. An example of such a locking mechanism is a Touhy-Borst adapter 200 (
In operation, the introducer sheath 106 may be inserted through the central bores 280, 282 and 272 of the cap 254, the compressible member 256 and the receiving member 252 separately, or the locking mechanism 250 may be threaded together prior to inserting the introducer sheath through the central bores 280, 282 and 272, generally provided that the compressible member 256 remains in an un-compressed state. Once the locking mechanism 250 is in the desired location, the threaded portion 264 of the cap 254 is threaded into the threaded socket 260 of the receiving member 252 and screwed down, resulting in axial translation of the generally tubular extension 274 toward the tapered portion 266 of the receiving member 252. The tapered surfaces of the tapered portion 266 and of the tubular extension 274 interact with the tapered portions 286 and 288 of the compressible member 256 to force an interior wall 290 of the compressible member 256 inward and apply pressure radially to the introducer sheath 106.
In general, the compressible member 256 may be made from any material that is suitably compressible to lock the delivery wire within the introducer sheath. Exemplary types of materials include rubbers, synthetic rubbers or other soft polymers, elastomers, and thermoplastic elastomers. Exemplary materials include Santoprenes™, silicones, polyurethanes, polyolefin, fluoropolymer, polyvinylidene fluoride, and Teflon®. The compressible member may be in the form of a deformable structure, which itself may be formed of a deformable material or a material that is not deformable. Exemplary deformable structures include braided, knit or woven metallic or polymeric structures and/or foams. Combinations of materials can be used.
While particular designs of the compressible member 256 have been shown, other designs may also be used. As an example, in some embodiments, the side wall of the compressible member 256 may have only a single taper.
Examples of materials from which sleeve 302 can be formed include resilient materials, for example, polymers, such as, for example, rubbers, plastics, and thermoplastic elastomers. In certain embodiments, the sleeve 302 may be formed of a heat shrunk material. Examples of heat shrunk materials include heat shrunk polyvinyl chlorides (PVCs), heat shrunk polytetrafluoroethylenes (PTFEs), heat shrunk polyolefins, heat shrunk fluoroethylene polymers (FEPs), and heat shrunk polyvinylidenedifluorides (PVDFs), and/or polyethylene terephthalates (PETs).
In some embodiments, an elastic sleeve as just described can be employed, where the sleeve has no perforations. The sleeve can be removed, e.g., by rolling the sleeve off of the junction of the introducer sheath and the delivery wire, permitting the delivery wire to be moved with respect to the introducer sheath. The sleeve can, if desired, be returned to the junction of the introducer sheath and the delivery wire, e.g., by rolling the sleeve back onto the junction, to re-lock the delivery wire, such that the delivery wire is substantially immobile longitudinally with respect to the introducer sheath. The sleeve could be formed of any of the resilient materials described above.
While certain embodiments have been described, others are possible.
As an example, in some embodiments, the locking mechanism could involve an iris-type opening for applying pressure radially against the introducer sheath.
As another example, while certain embodiments of springs have been described, other embodiments can be used. In some embodiments, the spring may be a leaf spring or a coiled spring. In certain embodiments, the spring may be unitary with the first or second extension. In some embodiments, the first extension, second extension and the spring may all be unitary and the biasing of the first and second extensions may arise from the configuration of these unitary components.
As a further example, while certain locking materials for locking mechanisms have been described, other materials can be used. In some embodiments, the locking mechanism can be formed of a shape memory material (e.g., a shape memory metal, a shape memory polymer). Typically, such materials are shaped to a first shape at a high temperature and are reshaped to a second shape following cooling, and upon subsequent reheating, the materials revert to the first shape.
As yet another example, in certain embodiments the introducer sheath can have an outer diameter of no more than about 2 mm (e.g., no more than about 1.5 mm, no more than about 1 mm, or no more than about 0.7 mm), and/or no less than about 0.5 mm (e.g., no less than about 0.7 mm, no less than about 1 mm, or no less than about 1.5 mm). For example, the introducer sheath can have an outer diameter of between about 0.5 mm and about 2 mm (e.g., between about 0.7 mm and about 1.5 mm).
As an additional example, in certain embodiments, the introducer sheath can have an inner diameter of no more than about 1 mm (e.g., no more than about 0.5 mm, no more than about 0.4 mm, or no more than about 0.3 mm), and/or no less than about 0.2 mm (e.g., no less than about 0.3 mm, no less than about 0.4 mm, or no less than about 0.5 mm). For example, in some embodiments, the introducer sheath can have an inner diameter of between about 1 mm and about 0.2 mm (e.g., between about 0.5 mm and about 0.2 mm, or about 0.4 mm and about 0.3 mm).
Other embodiments are in the claims.
