Pull wire detachment for intravascular devices

An assembly at a proximal end of an intravascular delivery system can allow the proximal end of a pull wire to move independently of a delivery tube. The assembly can generally include the pull wire, the delivery tube, a feature to prevent the proximal end of the pull wire from becoming inaccessible due to distal movement of the pull wire, and a feature to protect the proximal end of the pull wire from inadvertent, premature manipulation. When the intravascular delivery system is navigating tortuous vasculature, the proximal end of the pull wire can move distally in relation to the proximal end of delivery tube, relieving stress on the distal end of the pull wire. The proximal end of the pull wire can be protected from inadvertent manipulation during delivery and made available for manipulation once the distal end of the delivery system is in place.

FIELD OF INVENTION

The present invention generally relates to medical devices, and more particularly, to deploying intravascular implants.

BACKGROUND

Numerous intravascular implant devices and clot capture devices are known in the field. Many are deployed and manipulated mechanically, via systems that combine one or more catheters and wires for delivery. Examples of implants that can be delivered mechanically include embolic elements, stents, grafts, drug delivery implants, flow diverters, filters, stimulation leads, sensing leads, or other implantable structures delivered through a microcatheter. Some obstetric and gastrointestinal implants can also be implanted via similar systems that combine one or more catheters and wires. Devices that can be released, deployed, or otherwise manipulated by mechanical means vary greatly in design but can employ a similar delivery catheter and wire system.

Many such catheter-based implant delivery systems include an inner elongated member (or members) extending through the catheter that can be manipulated at the proximal end by a physician to deploy the implant. The inner elongated member(s) can retain the implant in the catheter until the time for release of the implant. These systems can be actuated by retracting or pulling one or more of the inner elongated member(s) relative to the catheter. Such a wire or inner elongated member is referred to herein generically as a “pull wire”.

Prematurely release of an implant while tracing through vasculature or before implantation is completed can lead to complications. Mitigating the likelihood of premature release can come at a cost of a less flexible mechanical release system. For instance, when delivering an embolic coil using a release system as described in U.S. Pat. No. 8,062,325 or as described in U.S. patent application Ser. No. 15/964,857, each incorporated herein by reference, it can be desirable to have a minimum length of pull wire extending within the embolic coil in order to minimize stiffening of the proximal end of the coil, however, this limited engagement can result in premature detachment of the coil if significant proximal movement of the pull wire occurs while tracking the delivery system through vasculature.

There is therefore a need for systems, devices, and methods that can mitigate the likelihood of premature deployment of an intravascular treatment device while also providing a flexible mechanical release system.

SUMMARY

It is an object of the present invention to provide systems, devices, and methods to meet the above-stated needs. Generally, it is an object of the present invention to provide an intravascular delivery system having an assembly at its proximal end that allows the proximal end of a pull wire to move independently of a delivery tube and methods for using and making the same to meet the above-stated needs. The assembly can generally include the pull wire, the delivery tube, a feature to prevent the proximal end of the pull wire from becoming inaccessible due to distal movement of the pull wire, and a feature to protect the proximal end of the pull wire from inadvertent, premature manipulation. When the intravascular delivery system is navigating tortuous vasculature, the proximal end of the pull wire can move distally in relation to the proximal end of delivery tube, relieving stress on the distal end of the pull wire. The proximal end of the pull wire can be protected from inadvertent manipulation during delivery and made available for manipulation once the distal end of the delivery system is in place.

In some examples, the feature preventing the proximal end of the pull wire from becoming inaccessible can include a combination of a bump positioned on the proximal end of the pull wire and an intermediate hypotube extending from the proximal end of the delivery tube and providing an engagement surface sized to inhibit the bump from entering the intermediate hypotube. The proximal end of the pull wire can thereby be free to move proximally and/or distally in relation to the hypotube, except when the bump is engaged to the engagement surface of the intermediate hypotube, in which case distal movement of the pull wire is inhibited.

In some examples, the intermediate hypotube can be stretchable. In such examples, the feature protecting the proximal end of the pull wire from inadvertent manipulation can include a breakable attachment that prevents the intermediate hypotube from stretching during delivery of the intravascular treatment device. To deploy the intravascular treatment device, the breakable attachment can be broken, the intermediate hypotube can be stretched, upon stretching, the proximal end of the pull wire can engage the intermediate hypotube, and upon further stretching, the proximal end of the pull wire can be moved in the proximal direction. Sufficient movement of the proximal end of the pull wire can result in proximal translation of the distal end of the pull wire. Sufficient proximal translation of the distal end of the pull wire can result in deployment of the intravascular treatment device.

In some examples, the feature protecting the proximal end of the pull wire from inadvertent manipulation can include a sheath that surrounds the proximal end of the pull wire. The sheath can be affixed to the intermediate hypotube and positioned to surround the proximal end of the pull wire. To deploy the intravascular treatment device, the sheath can be grasped and pulled in the proximal direction in relation to the delivery tube, causing the intermediate hypotube to stretch, and thereby causing the pull wire to engage the intermediate hypotube and translate in the proximal direction.

According to the present invention, an example intravascular delivery system can include a delivery tube, intermediate hypotube, and a pull wire. The intravascular device can be suitable for delivering an intravascular treatment device through patient vascular to a treatment site. To that end, the delivery tube can be sized to be delivered through a patent to a treatment site. During treatment, the intermediate hypotube can be positioned outside of the patent and need not be suitable for entering patent vasculature.

The intermediate hypotube can be affixed to the delivery tube and can extend in the proximal direction from the proximal end of the delivery tube. The pull wire can extend through the lumens of both the intermediate hypotube and the delivery tube. An engagement bump can be affixed to the pull wire and positioned in the proximal direction in relation to the intermediate hypotube proximal end.

The intravascular delivery system can further include a sheath attached to the intermediate hypotube. The sheath can surround the engagement bump and a proximal portion of the pull wire.

The engagement bump can be movable in the distal direction in relation to the proximal end of the intermediate hypotube. A stretch relief gap between the engagement bump and the intermediate hypotube can define a length of travel that the engagement bump can move in the distal direction before engaging the intermediate hypotube.

An intravascular treatment device can be positioned at the distal end of the intravascular delivery system. The pull wire can be movable to deploy the intravascular treatment device.

The distal end of the intermediate hypotube can be positioned within the lumen of the delivery tube. The intermediate hypotube can include an extendable section. The extendable section can be positioned within the lumen of the delivery tube.

An example method for assembling an intravascular delivery system can include one or more of the following steps presented in no particular order, and the method can include additional steps not included here. A delivery tube, intermediate hypotube, and pull wire can be provided. The delivery tube can be sized for delivery through patent vasculature. Both the provided delivery tube and intermediate hypotube can have a respective lumen therethrough.

The intermediate hypotube can be affixed to the delivery tube such that the intermediate hypotube extends in the proximal direction from the proximal end of the delivery tube.

To affix the intermediate hypotube to the delivery tube, a distal end of the intermediate hypotube can be affixed within the lumen of the delivery tube.

The intermediate hypotube can be provided with a strain relief section. To affix the intermediate hypotube to the delivery tube, the strain relief section can be positioned within the lumen of the delivery tube, a portion of the intermediate hypotube in the distal direction from the strain relief section can be affixed to the intermediate hypotube, and a portion of the intermediate hypotube in the proximal direction from the strain relief section can be detachably attached to the delivery tube.

An engagement bump can be formed at the proximal end of the pull wire. The pull wire can be positioned such that the engagement bump is in the proximal direction in relation to the proximal end of the intermediate hypotube and the length of the pull wire extends through the lumens of the intermediate hypotube and the delivery tube. The engagement bump can be sized to inhibit movement of the engagement bump into the lumen of the intermediate hypotube.

The pull wire can be positioned such that the distal end of the pull wire is fixed in relation to the distal end of the delivery tube and the proximal end of the pull wire is slidably translatable in relation to the proximal end of the delivery tube. The distal end of the pull wire can be positioned to secure an intravascular treatment device at the distal end of the delivery tube.

A stretch relief gap can be provided such that the stretch relief gap defines a length over which the engagement bump can move in the distal direction in relation to the intermediate hypotube without engaging the intermediate hypotube.

A sheath having a lumen therethrough can also be provided. The sheath can be affixed to the intermediate hypotube. The engagement bump can be positioned within the lumen of the sheath.

An example method for deploying an intravascular treatment device can include one or more of the following steps presented in no particular order, and the method can include additional steps not included here. An intravascular delivery system can be selected such that the selected delivery system includes a delivery tube, an intermediate hypotube extending from the proximal end of the delivery tube, and a pull wire extending through the lumens of the delivery tube and the intermediate hypotube. The intravascular delivery system can be extended through vasculature of a patient. As the delivery system is extended through the patient, the proximal end of the pull wire can be allowed to move in the distal direction in relation to the proximal end of the delivery tube. The intravascular treatment device can be deployed by moving the proximal end of the pull wire in the proximal direction in relation to the proximal end of the delivery tube.

The pull wire can have a bead positioned at or near the proximal end of the pull wire, and the bead can be engaged to the proximal end of the intermediate hypotube, thereby inhibiting the proximal end of the pull wire from entering the lumen of the intermediate hypotube.

The proximal end of the pull wire can be surrounded by a sheath. To deploy the intravascular treatment device, the sheath can be moved in the proximal direction in relation to the delivery tube. Movement of the sheath can cause the intermediate hypotube to elongate. Elongation of the intermediate hypotube can cause the proximal end of the pull wire to be engaged to the intermediate hypotube. The proximal end of the pull wire can be moved in the proximal direction in relation to the proximal end of the delivery tube by elongating the intermediate hypotube while the proximal end of the pull wire is engaged to the intermediate hypotube.

DETAILED DESCRIPTION

In at least some known intravascular delivery systems having a retractable pull wire, the proximal end of the pull wire is substantially fixed in relation to the proximal end of a delivery tube, the distal end of the pull wire is attached to a treatment device deployment system, and a majority of the length of the pull wire is free to move within the confines of the lumen of the delivery tube. When such a delivery system navigates tortuous anatomy, the length of the pull wire can tend to extend to the outer curves of the lumen of the delivery tube, thereby creating a strain force on the attached proximal and distal ends of the pull wire. If the proximal end of the pull wire is securely fixed in relation to the delivery tube, the strain can cause the distal end of the pull wire to move proximally. Significant proximal movement of the distal end of the pull wire can cause the implant or treatment device to deploy prematurely.

In examples presented herein, a slack mechanism can be built on the proximal end of an intravascular delivery system to allow the proximal end of the pull wire to move more freely compared to the distal end of the pull wire. When an example delivery system navigates tortuous anatomy, the proximal end of the pull wire can move distally in relation to the proximal end of the delivery tube to alleviate strain at the distal end of the pull wire, thereby reducing the likelihood that the implant or treatment device is deployed prematurely compared to existing intravascular delivery systems.

The figures illustrate a generally hollow or tubular structures according to the present invention. When used herein, the terms “tubular” and “tube” are to be construed broadly and are not limited to a structure that is a right cylinder or strictly circumferential in cross-section or of a uniform cross-section throughout its length. For example, the tubular structure or system is generally illustrated as a substantially right cylindrical structure. However, the tubular system may have a tapered or curved outer surface without departing from the scope of the present invention.

FIG. 1is an illustration of an example intravascular delivery system100. The system can include an assembly at its proximal end for providing strain relief at a distal end154of the pull wire150. The assembly is illustrated in greater detail inFIG. 2. The delivery system100can include a delivery tube110, a loop wire140attached to the delivery tube110near the distal end114of the delivery tube110, an intermediate hypotube130extending from a proximal end112of the delivery tube110, and the pull wire150. The delivery system100can secure an intravascular treatment device200such as an embolic coil210at the distal end104of the delivery system100for delivery to a treatment site, and the delivery system100can deploy the intravascular treatment device200by pulling the pull wire150proximally. InFIG. 1, the delivery tube110is shown in cross-section. InFIG. 2the delivery tube110and intermediate hypotube130are shown in cross-section.

The treatment device200can include an engagement feature230such as a key. The engagement feature can include an opening positioned at a proximal end of the treatment device200. The treatment device200can be secured to the delivery system100by feeding a portion of the loop wire140through the opening of the engagement feature230and extending the distal end154of the pull wire150through the loop wire140.

To deploy the treatment device200, the pull wire150can be pulled proximally such that the distal end154of the pull wire passes out of the opening in the loop wire140, thereby disengaging the loop wire140. Once the loop wire140is disengaged from the pull wire150, the loop wire140can be free to exit the opening in the engagement feature230.

The delivery tube110can include a compressible section118. The compressible section118can be under compression such that once the loop wire140is disengaged, the compressible section118can decompress, providing a force distally against the treatment device200. The loop wire140can have sufficient flexibility such that when the force is provided from the decompressing compressible section118, the loop moves out of the opening of the engagement feature230, thereby detaching the treatment device200from the delivery system100. The force provided from the compressible section118during decompression can also push the implant200distally away from the distal end104of the delivery system100, creating separation between the delivery system100and the treatment device200.

FIG. 2is an illustration of an example assembly at a proximal end of an intravascular delivery system100for providing strain relief at a distal end154of a pull wire150when the distal end154of the pull wire150is positioned to secure a treatment device200to the delivery system100. The distal end154of the pull wire150can secure the treatment device200to the delivery system100as described in relation toFIG. 1or by other means that can result in the treatment device200being deployed upon proximal movement of the pull wire150.

The assembly at the proximal end of the delivery system100can include the pull wire150, a delivery tube110, an intermediate hypotube130, and a sheath170. The pull wire150can extend within the delivery tube110, intermediate hypotube130, and sheath170. The intermediate hypotube130can be affixed to the delivery tube110and extend proximally from the delivery tube110. The pull wire150need not be solidly connected to the intermediate hypotube130, rather the proximal end of the pull wire150can be beaded such that a stretch relief gap190exists between the bead and the proximal end of the intermediate hypotube130. The gap190can allow the proximal end of the pull wire150to move in relation to the proximal end112of the delivery tube110and intermediate hypotube130during tracking in tortuous anatomy, thereby minimizing the potential for premature retraction of the pull wire150at its distal end.

The pull wire150can have a bead, bump, extension, protrusion, or other feature (referred to herein generically as “bead”)156at its proximal end152that extends in a radial direction beyond an outer circumference158of the pull wire150to a dimension that inhibits the bead156from entering the lumen136of the intermediate hypotube130. The intermediate hypotube130can have a proximal end132that is positioned a gap distance190from the bead. The proximal end132of the intermediate hypotube130can be sized to maintain a position distal to the proximal end of the pull wire150, so that if the gap190collapses during manipulation of the delivery system, the bead156is inhibited from entering the intermediate hypotube130.

Alternatively, the intermediate hypotube130can include an alternative engagement feature, such as an obstruction in the lumen of the intermediate hypotube. In which case, the bead156can be sized to enter the lumen136of the intermediate hypotube130, and the alternative engagement feature can prevent further distal movement of the bead156into the lumen136. In such an example, the gap distance190can be understood to be the length through which the bead156can travel in the distal direction in relation to the proximal end112of the delivery tube110before becoming engaged to the alternative engagement feature.

The assembly can further include a sheath170to cover a proximal portion of the pull wire150extending out of the intermediate hypotube132to prevent inadvertent manipulation and/or breakage of the pull wire150. The sheath170can be affixed to the intermediate hypotube section130with welds, glue, interference fit, or other means178. The sheath170can have a lumen176sized to fit over an outer circumference of the proximal end132of the intermediate hypotube130and at least a portion of the intermediate hypotube130. A surface within the lumen176of the sheath170can be detachably attached to an outer surface of the intermediate hypotube130.

The intermediate hypotube130can be affixed to the delivery tube110with welds, glue, interference fit, or other means124. The intermediate hypotube130can have an outer circumference sized to fit within the lumen of the delivery tube110. An outer surface of the intermediate hypotube130can be affixed to an inner surface of the lumen116of the delivery tube110such that the intermediate hypotube130is not easily detached from the delivery tube110during a treatment procedure.

The intermediate hypotube130can have an extendable section138positioned within the lumen116of the delivery tube110. The extendable section138can be stretched during a treatment procedure to elongate the intermediate hypotube130. The intermediate hypotube130can be affixed to the delivery tube110at an attachment point124that is in the distal direction14in relation to the extendable section138such that when the extendable section138is stretched, the intermediate hypotube130extends further in the proximal direction12from the proximal end112of the delivery tube110.

To prevent premature elongation of the intermediate hypotube130, the intermediate hypotube can be attached with a breakable attachment122to the delivery tube110on a proximal side of the extendable section138, near the proximal end112of the delivery tube110.

The extendable section138can include areas of the intermediate hypotube130where sections have been cut or removed. By way of illustration,FIG. 2shows the strain relief section138having a spiral cut in the hypotube130.

The intermediate hypotube130can have a length that is significantly shorter than the length of the delivery tube110. During a treatment, the proximal end112of the delivery tube110can be positioned outside of the patient while the distal end114of the delivery tube is positioned near a treatment site within the patient. While the delivery tube110is positioned as described, the proximal end132of the intermediate hypotube130can be positioned outside of the patient, and the intermediate hypotube130need not extend into the patient.

FIG. 3illustrates positioning of an implant200such as an embolic coil suitable for aneurysm treatment, a guide catheter300, and a delivery system100including a delivery tube110and pull wire150within tortuous vasculature (vasculature not illustrated). At bends A, B, and C, the delivery tube110can extend to a sidewall of the guide catheter300on each outer curve of each bend, and likewise, the pull wire150can extend to a sidewall of the delivery tube110on each outer curve of each bend. During a procedure, the delivery tube110and pull wire150can be fed into the guide catheter300in the distal direction, first passing through bend A, then bend B, and then bend C. As the delivery tube110and pull wire150navigate the bends, the proximal end152of the pull wire150can progressively approach the proximal end132of the intermediate hypotube130, such that the pull wire150proximal end152moves in the distal direction14in relation to the delivery tube110.

FIGS. 4A through 4Dillustrate the progressive movement of the proximal end152of the pull wire150as the delivery system100moves distally through bends A, B, and C.FIG. 4Aillustrates the positioning of the proximal end152of the pull wire150as the distal end104of the delivery system100approaches bend A.FIG. 4Billustrates the movement of the proximal end152of the pull wire150toward the intermediate hypotube130as the distal end104of the delivery system100rounds bend A and approaches bend B.FIG. 4Cillustrates the proximal end of the pull wire150moving further toward the intermediate hypotube130as the distal end104of the delivery system100rounds bend B and approaches bend C.FIG. 4Dillustrates the bead on the proximal end of the pull wire150making contact with the proximal end of the intermediate hypotube130as the distal end104of the delivery system100rounds bend C and approaches a treatment site.

Referring collectively to the illustrations inFIGS. 3 and 4A through 4D, as the delivery system100is moved distally to a treatment site, the proximal end152of the pull wire150can be free to move in the proximal and distal directions in relation to the delivery tube110and intermediate hypotube130. As illustrated, the bead156on the pull wire150can approach the proximal end of the hypotube130as the delivery system100is moved distally to a treatment site. Arrows illustrated inFIGS. 4B through 4Dindicate the distal movement of the proximal end152of the pull wire150.

A gap190a,190b,190c,190dbetween the bead156and the engagement surface132of the intermediate hypotube can become progressive smaller as illustrated inFIGS. 4A through 4Das the delivery system100is moved distally. InFIG. 4Dthe bead156is illustrated engaged to the intermediate hypotube130. In this position, the proximal end152of the pull wire150is inhibited from moving further in the distal direction14and the gap190dspacing is collapsed, essentially measuring zero.

Referring toFIG. 2, the delivery system100can include a gap spacing190that is measurable between a distal surface of the bead156and the engagement surface132of the intermediate hypotube130when the delivery system100is elongated in an essentially linear configuration from end to end. The gap spacing190can be sized such that the bead156is unlikely to engage the hypotube130as the delivery system100is delivered to a treatment site. A larger gap spacing can allow for a greater distance of travel of the proximal end152of the pull wire150, allowing for greater strain relief at the distal end of the pull wire, thereby reducing the likelihood of premature deployment of a treatment device. The maximum length of the gap spacing190can be limited by ease of manipulation of the proximal end of the delivery system100. For example, it may be difficult for a physician to manipulate a delivery system having a proximal assembly such as illustrated inFIG. 2that is several inches long. The gap190can therefore be sized to sufficiently relieve strain on the distal end of the pull wire150to sufficiently reduce the likelihood of premature deployment of a treatment device and also to facilitate ease of manipulation of the delivery system during a treatment procedure.

FIGS. 5A and 5Billustrate the manipulation of the assembly at the proximal end of the delivery system100to deploy a treatment device (e.g. implant).FIG. 5Cillustrates the movement of the distal end154of the pull wire150to disengage the implant200in response to the manipulation of the proximal end of the delivery system illustrated inFIGS. 5A and 5B.

FIG. 5Aillustrates the sheath170covering a proximal portion of the pull wire150including the proximal end152and bead156, the sheath170affixed to the intermediate hypotube130with welds178, the intermediate hypotube being affixed to the delivery tube110with distal welds124, and the intermediate hypotube130also secured to the delivery tube at the proximal end of the delivery tube100with proximal welds122. The proximal welds122can be designed to be broken by a user during a treatment, while the other welds178,124affixing the intermediate hypotube120to the sheath170and delivery tube110can be designed to remain securely attached when the assembly is manipulated during a treatment.

FIG. 5Billustrates the sheath170being pulled proximally as indicated by the arrow. During a treatment, a user can apply a force F sufficient to break the proximal welds122to detach the proximal end112of the delivery tube110from the intermediate hypotube130. Alternatively, the proximal welds128can be broken with a twisting or bending force. After welds128are broken, the sheath170can be moved proximally as indicated by the arrow. The extendable section138of the intermediate hypotube130can expand, allowing the intermediate hypotube130to further extend out of the proximal end112of the delivery tube110. As the sheath170is moved proximally and the intermediate hypotube130is extended, the intermediate hypotube130can engage the bead156on the pull wire150. As the sheath170is further moved proximally and the intermediate hypotube130is further extended, the bead156can be moved proximally, causing the length of the pull wire150to move proximally.

FIG. 5Cillustrates the distal end154of the pull wire150extended through the loop wire140. The arrow indicates proximal movement of the distal end154of the pull wire150in response to the bead156on the pull wire150being moved proximally as illustrated inFIG. 5B. The bead156can be moved proximally through a distance sufficient to cause the distal end154of the pull wire to pass proximally through the loop wire140, thereby disengaging the loop wire140. Once the loop wire140is disengaged, the implant100can deploy.

FIG. 6is a flow chart outlining example method steps for designing and/or constructing a delivery system according to the present invention.FIG. 7is a flow chart outlining example method steps for treating a patient using a delivery system according to the present invention. For each method600,700, the method steps can be implemented by the example delivery systems and means described herein or by means that would be known to one of ordinary skill in the art. Method steps are generally presented in an order in which they can be preferably performed. Certain steps can be performed simultaneously or in alternative order as would be appreciated and understood by one of ordinary skill in the art.

Referring to the method600outlined inFIG. 6, in step610a delivery tube, intermediate hypotube, and pull wire can be provided. The provided components can be the delivery tube110, intermediate hypotube130, and pull wire150described herein, a variation thereof, or an equivalent component as would be known to one skilled in the art.

In step620, an engagement bump can be formed near the proximal end of the pull wire, and the engagement bump can be sized larger than lumen of the intermediate hypotube such that the engagement bump inhibits the proximal end of the pull wire from entering the lumen of the intermediate hypotube. The engagement bump can be a bead156on the pull wire150as described herein, a variation thereof, or an equivalent component as would be known to one skilled in the art.

In step630, the intermediate hypotube can be affixed to the delivery tube such that the intermediate hypotube extends proximally from the delivery tube and is stretchable to further extend proximally from the proximal end of the delivery tube. The intermediate hypotube can be affixed at the distal attachment location124as illustrated herein, otherwise attached as described herein, and/or attached by other means as would be known to one skilled in the art. The intermediate hypotube can be stretchable along a portion138of its length as illustrated herein, otherwise stretchable as described herein, and/or extendable by other means as would be known to one skilled in the art.

In step640, the pull wire can be positioned such that the wire extends through the lumens of the intermediate hypotube and delivery tube, the pull wire extends proximally from the lumen of the intermediate hypotube, and the engagement bump is positioned in the proximal direction in relation to the intermediate hypotube.

In step650, an intravascular treatment device can be secured with a distal portion of the pull wire at a distal end of the delivery tube. The intravascular treatment device can be an embolic coil200as illustrated herein, another treatment device as described herein, or a treatment device that would be known to one skilled in the art. The distal portion of the pull wire can form part of an assembly that can secure the treatment device when the treatment device is being delivered and deploy the treatment device with a proximal movement of the distal portion of the pull wire in relation to the treatment device and/or distal end of the delivery tube. The assembly to deploy the treatment device can be a mechanical assembly such as illustrated and/or described herein, or an assembly as would be known to one skilled in the art.

In step660, the pull wire can be positioned such that the distal end of the pull wire is fixed in relation to the distal end of the delivery tube and the proximal end of the pull wire is slidably translatable in relation to the proximal end of the delivery tube. The distal end of the pull wire can be fixed in relation to the distal end of the delivery tube by virtue of forming part of an assembly that secures the treatment device when the treatment device is being delivered to the treatment site. The portion of the pull wire forming the assembly to secure the treatment device can be the sole attachment point between the pull wire such that a majority of the length of the pull wire has freedom of movement within the confines of the delivery tube, and the proximal end of the pull wire is free to move in the distal direction and proximal direction in relation to the proximal end of the delivery tube.

In step670, a sheath can be affixed to the intermediate hypotube. The sheath can be positioned to surround the proximal end of the pull wire. The sheath can be a sheath170as illustrated and described herein, a variation thereof, or an equivalent component as would be known to one skilled in the art. The sheath can be attached to the intermediate hypotube at locations178as illustrated herein, otherwise attached as described herein, and/or attached by other means as would be known to one skilled in the art. The sheath can be shaped to be grasped by a physician during a treatment.

Referring to the method700outlined inFIG. 7, in step710an intravascular delivery system having a delivery tube, intermediate hypotube, and pull wire can be selected. The intravascular delivery system can be an example delivery system100described herein, a variation thereof, or an equivalent system as would be known to one skilled in the art.

In step720, the proximal end of the pull wire can be surrounded by a sheath. The sheath can be a sheath170as illustrated and described herein, a variation thereof, or an equivalent component as would be known to one skilled in the art. The proximal end of the pull wire can be surrounded by the sheath in step720by virtue of the selected intravascular delivery system (step710) including the sheath positioned to surround the proximal end of the pull wire. Alternatively, the sheath can be an ancillary component selected separately from the intravascular delivery system, and the sheath can be positioned to surround the proximal end of the pull wire in step720. In either case, the sheath, when attached, can serve to protect the proximal end of the pull wire from inadvertent manipulation and/or breakage.

In step730, the delivery system can be extended through vasculature of a patient.

In step740, the proximal end of the pull wire can be allowed to move distally in relation to the proximal end of the delivery tube as the delivery system is extended through vasculature of the patient.

In step750, the proximal end of the pull wire can be inhibited from entering the intermediate hypotube and delivery tube by engaging a bead on the pull wire to the hypotube.

In step760, the sheath can be moved to elongate the intermediate hypotube.

In step770, the proximal end of the pull wire can be engaged and moved by elongating the intermediate hypotube.

In step780, a treatment device can be deployed by moving the proximal end of the pull wire proximally in relation to the proximal end of the delivery tube.

The descriptions contained herein are examples of embodiments of the invention and are not intended in any way to limit the scope of the invention. As described herein, the invention contemplates many variations and modifications of the intravascular delivery system, including alternative components, alternative features to prevent the proximal end of the pull wire from becoming inaccessible due to distal movement of the pull wire, alternative features to protect the proximal end of the pull wire from inadvertent, premature manipulation, alternative means for extending the intermediate hypotube from the proximal end of the delivery tube, etc. These modifications would be apparent to those having ordinary skill in the art to which this invention relates and are intended to be within the scope of the claims which follow.