Vascular-malformation implant systems

Abstract

An implant (20) is provided that includes an implant wire (30) and a retention portion (38). A tubular tip (52) of a delivery tube (50) defines a tubular wall (48) defining a lumen (46), a tip distal opening (56), a lateral window (72), and a tubular distal portion (58) axially between a distal end (82) of the lateral window (72) and the tip distal opening (56). The retention portion (38) is removably disposed entirely within the lumen (46) of the tubular tip (52). A pull wire (60) is removably disposed partially within the tubular tip (52), so as to define a pull-wire distal portion (62), disposed at least partially within the tubular distal portion (58) to effectively reduce an inner diameter of an axial portion of the tubular distal portion (58) to be too small for the retention portion (38) to pass through. The retention portion (38) is disposed alongside a pull-wire intermediate portion (78), which is disposed at least partially within the lateral window (72). Other embodiments are also described.

Description

[0001] VASCULAR-MALFORMATION IMPLANT SYSTEMS

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] The present application claims priority from US Provisional Application 63 / 638,619, filed April 25, 2024, and US Provisional Application 63 / 699,452, filed September 26, 2024. All of the above-mentioned applications are assigned to the assignee of the present application and incorporated herein by reference.

[0004] FIELD OF THE APPLICATION

[0005] The present invention relates generally to minimally-invasive techniques for treating vascular malformations such as aneurysms.

[0006] BACKGROUND OF THE APPLICATION

[0007] An aneurysm is an abnormal local dilation of an artery caused by a weakening of the artery wall. In the past, cerebral aneurysms were frequently treated by direct surgical intervention, such as by installing a clip around the base of the aneurysm to prevent passage of blood between the aneurysm and the lumen of the vessel. Attempts have then been made to develop minimally-invasive techniques for treating such aneurysms, for example, by filling the aneurysm with endovascular embolization coils, such that the aneurysm eventually becomes a solid mass of coils and thrombus.

[0008] WO 2017 / 070171 to Tassoni et al. describes an embolic coil delivery assembly. The delivery system may include a tubular member having a distal portion, a proximal portion and a lumen extending therein. The system may further include a tip member secured to the tubular member. The tip member may include a distal portion and a bonding portion. The bonding portion may include a bonding surface. The system may also include an embolic coil releasably disposed within the distal portion of the tip member. The distal portion of the tubular member may extend over the bonding portion of the tip member. The bonding surface may be configured to mechanically interlock with the tubular member.

[0009] US 8,333,796 to Tompkins et al. describes embolic coil implant systems and methods whereby coils are mechanically detachable. The coils include a retention element that may be releasably retained within the distal end of an implant tool. The implant tool may include a fulcrum configured to engage a first filament and prevent the release of the coil when the first filament is engaged. Alternatively, an urging means and aperture may be disposed within the sidewall of the implant tool, and a first filament may, in conjunction with the aperture and sidewall, releasably retain the coil until the first filament is withdrawn. The implant tool may also include an alignment member for aligning the first filament.

[0010] US 10,932,933 to Bardsley et al. describes a medical system for delivering and deploying a medical implant, and the method of using thereof. Specifically, one aspect of the teachings provides a medical system having an implant with an engagement loop, and a delivery system having an engagement wire and an interface. During implant delivery, the engagement wire engages the engagement loop of the implant. The engagement wire further interacts with the interface in order to prevent unintended disengagement of the engagement loop from the engagement wire. Certain embodiment of the present teaching also includes an implant release control mechanism fixedly attaching to a proximal end of the engagement wire. During implant delivery, the implant release control mechanism attaches the proximal end of the delivery system. During implant deployment, the implant release control mechanism detaches the proximal end of the delivery system.

[0011] US 8,864,790 to Strauss et al. describes an intravascular implant delivery system that carries an implant by retaining an engagement member engaging the implant in a position proximal of an aperture at a distal end of the delivery system. The engagement member is retained proximal to the aperture by a cord that obstructs the movement of the engagement member through the aperture. The engagement member is free to rotate and move within an area defined by the delivery system, allowing the implant to react to forces imparted to the implant by the movement of the delivery system and implant through a delivery catheter. Once the implant is in a desired implant position, the cord is moved away from an aperture and the engagement member is allowed to move away from the delivery system.

[0012] US Patent Application Publication 2022 / 0117606 to Montidoro et al. describes an assembly at a proximal end of an intravascular delivery system that 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.

[0013] SUMMARY OF THE APPLICATION

[0014] Applications of the present invention provide implant systems that comprise an implant and an intravascular delivery tool for delivering the implant to a site within a patient. The implant may be configured to treat a vascular malformation, such as an aneurysm. Optionally, the implant system further comprises the implant.

[0015] In some applications of the present invention, the implant comprises an implant wire, which includes an implant- wire proximal end portion that includes a proximal end of the implant wire. The implant further comprises a retention portion, which is disposed at the proximal end of the implant wire. The retention portion has as a greatest width that is greater than a diameter of the implant- wire proximal end portion.

[0016] In some applications of the present invention, the intravascular delivery tool comprises a delivery tube, a tubular tip, and a pull wire. The tubular tip is fixed to a distal end of the delivery tube. The tubular tip is shaped so as to define (i) a tubular wall having an inner surface that defines a lumen of the tubular tip, (ii) a tip distal opening, (iii) a lateral window, and (iv) a tubular distal portion axially between a distal end of the lateral window and the tip distal opening. The retention portion is removably disposed entirely within the lumen of the tubular tip.

[0017] The pull wire is removably disposed partially within the tubular tip, so as to define the following portions:

[0018] • a pull-wire proximal portion, which passes through a proximal end of the tubular tip,

[0019] • a pull- wire distal portion, which is disposed at least partially within the tubular distal portion so as to effectively reduce an inner diameter of at least an axial portion of tubular distal portion to be too small for the retention portion to pass through, thereby retaining the retention portion within the tubular tip, and

[0020] • a pull-wire intermediate portion, which is disposed at least partially within the lateral window; the pull-wire intermediate portion is axially between the pull-wire proximal portion and the pull-wire distal portion, and the retention portion is disposed alongside the pull-wire intermediate portion. For some applications, the pull-wire distal portion is removably disposed passing through the tip distal opening so as to effectively reduce an inner diameter of the tip distal opening to be too small for the retention portion to pass through, thereby retaining the retention portion within the tubular tip.

[0021] The implant system is configured such that proximal pulling on the pull wire allows retention portion to pass through the tubular tip. The proximal pulling does this by proximally retracting the pull wire from the tubular distal portion, thereby allowing the retention portion to pass through the tip distal opening, by increasing the effective available size of the tubular distal portion. This allows release of the retention portion (and thus the implant) from the tubular tip.

[0022] For some applications, the retention portion comprises a metal alloy comprising nickel and titanium (e.g., Nitinol). For some applications, the pull-wire intermediate portion comprises a metal alloy comprising nickel and titanium (e.g., Nitinol). Metal alloys comprising nickel and titanium are more flexible than stainless steel, which allows the pullwire intermediate portion to be disposed at least partially within the lateral window.

[0023] The inventors performed experiments using implant systems unlike the implant systems of the recited invention. In these other implant systems (which had a tubular tip similar in some respects to the tip member of above-mentioned WO 2017 / 070171 to Tassoni et al.), the retention portion was initially disposed partially within a lateral window, and a pull wire was disposed alongside the retention portion but not within the lateral window. The inventors found that the retention portion sometimes became stuck and was difficult to release from the tubular tip. In these experiments, the retention portion comprised Nitinol, which is a very soft metal, and thus took the shape of the lateral window over time, contributing to the retention portion becoming stuck in the lateral window.

[0024] In some applications of the present invention, an intravascular delivery tool is provided that comprises:

[0025] • a delivery tube, which comprises a tubular wall defining a lumen and integrally defining a blocking portion that protrudes into the lumen; and

[0026] • a pull wire, which (a) comprises a proximal stopper at a proximal end portion of the pull wire, and (b) is disposed at least partially within the lumen such that the proximal stopper is within the lumen proximal to the blocking portion. The blocking portion is shaped so as to block distal movement of the proximal stopper distally beyond the blocking portion. For some applications, the blocking portion is integrally defined by one or more indentations in the tubular wall. For some other applications, the blocking portion is integrally defined by a tab cut from the tubular wall.

[0027] The definition of the blocking portion by the tubular wall of the delivery tube provides the delivery system with reliability, in part because the system does not require additional elements that might be more prone to breakage.

[0028] In some applications of the present invention, the delivery tube is configured such that a proximal portion of the tubular wall of the delivery tube is separable from a distal portion of the tubular wall of the delivery tube at a predefined separation border along the tubular wall distal to the blocking portion. The pull wire is pulled proximally by separating the proximal portion of the tubular wall from the distal portion of tubular wall at the predefined separation border, and moving the proximal portion of the tubular wall proximally such that the blocking portion pushes the proximal stopper proximally, thereby proximally pulling on the pull wire.

[0029] There is therefore provided, in accordance with an application of the present invention, an implant system including:

[0030] (a) an implant, which includes:

[0031] (i) an implant wire, which includes an implant-wire proximal end portion that includes a proximal end of the implant wire; and

[0032] (ii) a retention portion, which is disposed at the proximal end of the implant wire, and which has a greatest width that is greater than a diameter of the implant-wire proximal end portion, the greatest width measured perpendicular to a central longitudinal axis of the implant-wire proximal end portion; and

[0033] (b) a delivery tool, which includes:

[0034] (i) a delivery tube;

[0035] (ii) a tubular tip, which is (A) fixed to a distal end of the delivery tube and (B) shaped so as to define (1) a tubular wall having an inner surface that defines a lumen of the tubular tip, (2) a tip distal opening, (3) a lateral window, and (4) a tubular distal portion axially between a distal end of the lateral window and the tip distal opening, wherein the retention portion is removably disposed entirely within the lumen of the tubular tip; and (iii) a pull wire, which is removably disposed partially within the tubular tip, so as to define the following portions:

[0036] (A) a pull-wire proximal portion, which passes through a proximal end of the tubular tip,

[0037] (B) a pull-wire distal portion, which is disposed at least partially within the tubular distal portion so as to effectively reduce an inner diameter of at least an axial portion of the tubular distal portion to be too small for the retention portion to pass through, thereby retaining the retention portion within the tubular tip, and

[0038] (C) a pull-wire intermediate portion, which is disposed at least partially within the lateral window, wherein the pull-wire intermediate portion is axially between the pull-wire proximal portion and the pull- wire distal portion, and wherein the retention portion is disposed alongside the pull-wire intermediate portion, wherein the implant system is configured such that proximal pulling on the pull wire allows the retention portion to pass through the tubular tip.

[0039] For some applications, the pull-wire distal portion is removably disposed passing through the tip distal opening so as to effectively reduce an inner diameter of the tip distal opening to be too small for the retention portion to pass through.

[0040] For some applications, the pull-wire distal portion is removably disposed entirely within the tubular distal portion.

[0041] For some applications, the tubular wall defines a complete perimeter of the lateral window.

[0042] For some applications, the pull-wire intermediate portion does not protrude out of the lateral window beyond an outer surface of the tubular tip.

[0043] For some applications, the delivery tool further includes a proximal stopper, which is disposed within the lumen of the tubular tip proximal to the retention portion, so as to prevent proximal motion of the retention portion beyond the proximal stopper.

[0044] For some applications, the proximal stopper is defined by a tab cut from the tubular wall and folded inwardly into the lumen of the tubular tip. For some applications, the retention portion includes a metal alloy including nickel and titanium.

[0045] For some applications, the pull-wire intermediate portion includes a metal alloy including nickel and titanium.

[0046] For some applications, at least a portion of the pull-wire proximal portion includes a metal alloy including nickel, titanium, and at least one other metal that provides the at least a portion of the pull-wire proximal portion with a ductility less than a ductility of metal alloys that include only nickel and titanium.

[0047] For some applications, at least a portion of the pull-wire proximal portion includes a metal alloy including nickel, titanium, and niobium.

[0048] For some applications, the tubular wall of the tubular tip includes stainless steel.

[0049] For some applications, the retention portion and the implant- wire proximal end portion are integral with each other and fabricated from a single piece of material.

[0050] For some applications, the retention portion and the implant- wire proximal end portion are fabricated from separate respective pieces of material fixed together.

[0051] For some applications, the tubular tip does not taper toward the tip distal opening.

[0052] For some applications, the retention portion is spherical.

[0053] For some applications, the spherical retention portion has a diameter of 0.05 - 2 mm.

[0054] For some applications, a greatest width of the lateral window is no more than 90% of a diameter of the spherical retention portion.

[0055] For some applications, the greatest width of the lateral window is no more than 80% of the diameter of the spherical retention portion.

[0056] For some applications, an axial length of the lateral window equals at least 150% of an axial length of the retention portion.

[0057] For some applications, an axial length of the lateral window equals at least 100% of a greatest outer diameter of the tubular tip.

[0058] For some applications, the axial length of the lateral window equals at least 150% of the greatest outer diameter of the tubular tip. For some applications, an axial length of the lateral window equals at least 200% of a greatest width of the lateral window.

[0059] For some applications, a greatest width of the lateral window is no more than 90% of the greatest width of the retention portion.

[0060] For some applications, the greatest width of the lateral window is no more than 80% of the greatest width of the retention portion.

[0061] For some applications, the pull-wire intermediate portion has a radius of curvature of at least 0.5 mm.

[0062] For some applications, a distance between a distal-most point of the lateral window and a distal end of the tubular tip is no more than 0.1 mm.

[0063] For some applications, a distance between a distal-most point of the lateral window and a distal end of the tubular tip is no more than 50% of an axial length of the retention portion.

[0064] For some applications, the greatest inner diameter of the tubular tip is 0.15 - 0.3 mm.

[0065] For some applications, a greatest outer diameter of the tubular tip is 0.15 - 0.5 mm.

[0066] For some applications, the greatest width of the retention portion equals at least 125% of the diameter of the implant- wire proximal end portion.

[0067] For any of the applications described above: the implant wire further may further include a coil-wire portion that is distally adjacent to the implant-wire proximal end portion, and the implant may further include a coil, which is coiled around the coil- wire portion and not around the implant-wire proximal end portion.

[0068] For some applications, the pull wire is removably disposed partially within the tubular tip such that the pull- wire distal portion passes through the tip distal opening and through a portion of the coil alongside a portion of the coil- wire portion of the implant wire.

[0069] For some applications, a length of the portion of the coil-wire portion alongside which the pull wire is disposed is 0.1 - 5 mm.

[0070] For some applications, a proximal end of the coil touches an external distal surface of the tubular tip. For some applications, the implant includes an intravascular coil.

[0071] For some applications, at least 75% of a combined length of (a) the implant- wire proximal end portion and (b) the retention portion is disposed within the tubular tip.

[0072] For some applications, at least 90% of the combined length is disposed within the tubular tip.

[0073] For some applications, the implant-wire proximal end portion is disposed entirely within the tubular tip.

[0074] For some applications, at least 50% of a length of the implant-wire proximal end portion is disposed within the tubular tip.

[0075] For some applications, at least 75% of the length of the implant- wire proximal end portion is disposed within the tubular distal tip.

[0076] For some applications, an axial portion of the implant-wire proximal end portion is disposed outside and distal to the tubular distal tip, the axial portion having a length of less than 0.1 mm.

[0077] There is further provided, in accordance with an application of the present invention, a method including: inserting a microcatheter into a blood vessel while a delivery tool and an implant of an implant system are removably disposed in the microcatheter, wherein the implant includes (i) an implant wire, which includes an implantwire proximal end portion that includes a proximal end of the implant wire, and (ii) a retention portion, which is disposed at the proximal end of the implant wire, and which has a greatest width that is greater than a diameter of the implant-wire proximal end portion, the greatest width measured perpendicular to a central longitudinal axis of the implant-wire proximal end portion, and wherein the delivery tool includes (i) a delivery tube; (ii) a tubular tip, which is (A) fixed to a distal end of the delivery tube and (B) shaped so as to define (1) a tubular wall having an inner surface that defines a lumen of the tubular tip, (2) a tip distal opening, (3) a lateral window, and (4) a tubular distal portion axially between a distal end of the lateral window and the tip distal opening, wherein the retention portion is removably disposed entirely within the lumen of the tubular tip; and (iii) a pull wire, which is removably disposed partially within the tubular tip, so as to define the following portions: (A) a pull-wire distal portion, which is disposed at least partially within the tubular distal portion so as to effectively reduce an inner diameter of at least an axial portion of the tubular distal portion to be too small for the retention portion to pass through, thereby retaining the retention portion within the tubular tip, and (C) a pull-wire intermediate portion, which is disposed at least partially within the lateral window, wherein the pull-wire intermediate portion is axially between the pull- wire proximal portion and the pull- wire distal portion, and wherein the retention portion is disposed alongside the pull-wire intermediate portion; advancing the microcatheter in the blood vessel; deploying the implant from the microcatheter; and releasing the implant from the delivery tool by proximally pulling on the pull wire so as to allow the retention portion to pass through the tubular tip.

[0078] For some applications: advancing the microcatheter in the blood vessel includes advancing the microcatheter in the blood vessel toward a vascular malformation, and deploying the implant from the microcatheter includes deploying the implant from the microcatheter into the vascular malformation.

[0079] For some applications, inserting the microcatheter into the blood vessel includes inserting the microcatheter into the blood vessel while the pull- wire distal portion is removably disposed passing through the tip distal opening so as to effectively reduce an inner diameter of the tip distal opening to be too small for the retention portion to pass through.

[0080] For some applications, inserting the microcatheter into the blood vessel includes inserting the microcatheter into the blood vessel while the pull- wire distal portion is removably disposed entirely within the tubular distal portion.

[0081] For some applications, inserting the microcatheter into the blood vessel includes inserting the microcatheter into the blood vessel while the pull-wire intermediate portion does not protrude out of the lateral window beyond an outer surface of the tubular tip.

[0082] For some applications, the retention portion is spherical.

[0083] For any of the applications described above, the implant wire may further include a coil- wire portion that is distally adjacent to the implant- wire proximal end portion, and the implant may further include a coil, which is coiled around the coil-wire portion and not around the implant-wire proximal end portion. For some of these applications, inserting the microcatheter into the blood vessel includes inserting the microcatheter into the blood vessel while the pull wire is removably disposed partially within the tubular tip such that the pull-wire distal portion passes through the tip distal opening and through a portion of the coil alongside a portion of the coil-wire portion of the implant wire. Alternatively or additionally, for some of these applications, inserting the microcatheter into the blood vessel includes inserting the microcatheter into the blood vessel while a proximal end of the coil touches an external distal surface of the tubular tip. Further alternatively or additionally, for some applications, the implant includes an intravascular coil. Still further alternatively or additionally, for some applications, inserting the microcatheter into the blood vessel includes inserting the microcatheter into the blood vessel while at least 75% of a combined length of (a) the implant-wire proximal end portion and (b) the retention portion is disposed within the tubular tip. Further alternatively or additionally, for some applications, inserting the microcatheter into the blood vessel includes inserting the microcatheter into the blood vessel while at least 50% of a length of the implant-wire proximal end portion is disposed within the tubular tip.

[0084] There is still further provided, in accordance with an application of the present invention, an intravascular delivery tool including: a delivery tube, which includes a tubular wall defining a lumen and integrally defining a blocking portion that protrudes into the lumen; and a pull wire, which (a) includes a proximal stopper at a proximal end portion of the pull wire, and (b) is disposed at least partially within the lumen such that the proximal stopper is within the lumen proximal to the blocking portion, wherein the blocking portion is shaped so as to block distal movement of the proximal stopper distally beyond the blocking portion.

[0085] For some applications, the blocking portion is integrally defined by one or more indentations in the tubular wall.

[0086] For some applications, the blocking portion is integrally defined by a tab cut from the tubular wall.

[0087] For some applications, the pull wire extends out of a distal end of the lumen. For some applications, a distance between the blocking portion and a proximal end of the lumen is at least 5 mm when the delivery tube is straight.

[0088] For some applications, the proximal stopper is positioned within the lumen between the blocking portion and a proximal end of the lumen at at least a non-zero distance from the blocking portion when the delivery tube is straight.

[0089] For some applications, the non-zero distance between the proximal stopper and the blocking portion is at least 4 mm to when the delivery tube is straight.

[0090] For some applications, a distance between the proximal stopper and a proximal end of the lumen is at least 2 mm when the delivery tube is straight.

[0091] For some applications, a distal end of the delivery tube is disposed within 1 cm of a distal end of the delivery tool, or coincides with the distal end of the delivery tool.

[0092] For some applications, the delivery tube has a length of at least 1 meter.

[0093] For some applications, the delivery tube is configured such that a proximal portion of the tubular wall of the delivery tube is separable from a distal portion of the tubular wall of the delivery tube at a predefined separation border along the tubular wall distal to the blocking portion.

[0094] For some applications, the delivery tube is configured such that the proximal portion of the tubular wall is severable from the distal portion of the tubular wall of the delivery tube at the predefined separation border.

[0095] For some applications, the tubular wall is heat-treated at the predefined separation border.

[0096] For some applications, the tubular wall is scored at the predefined separation border.

[0097] For some applications, the tubular wall is perforated at the predefined separation border.

[0098] For some applications, an implant system is provided that includes the intravascular delivery tool and further includes an implant which is disposed near a distal end of the intravascular delivery tool, and the intravascular system is configured such that proximal pulling of the pull wire releases the implant from the intravascular delivery tool.

[0099] There is additionally provided, in accordance with an application of the present invention, a method including: inserting a microcatheter into a blood vessel while an intravascular delivery tool is removably disposed in the microcatheter, and an implant is removably disposed in the microcatheter near a distal end of the intravascular delivery tool, wherein the intravascular delivery tool includes (i) a delivery tube that includes a tubular wall defining a lumen and integrally defining a blocking portion that protrudes into the lumen, and (ii) a pull wire, which (a) includes a proximal stopper at a proximal end portion of the pull wire, and (b) is disposed at least partially within the lumen such that the proximal stopper is within the lumen proximal to the blocking portion, and wherein the blocking portion is shaped so as to block distal movement of the proximal stopper distally beyond the blocking portion; advancing the microcatheter, and the delivery tube removably disposed therein, in the blood vessel; deploying the implant from the microcatheter; and releasing the implant from the delivery tool by proximally pulling on the pull wire.

[0100] For some applications, the blocking portion is integrally defined by one or more indentations in the tubular wall.

[0101] For some applications, the blocking portion is integrally defined by a tab cut from the tubular wall.

[0102] For some applications, the pull wire extends out of a distal end of the lumen.

[0103] For some applications, a distance between the blocking portion and a proximal end of the lumen is at least 5 mm when the delivery tube is straight.

[0104] For some applications, the proximal stopper is positioned within the lumen between the blocking portion and a proximal end of the lumen at at least a non-zero distance from the blocking portion when the delivery tube is straight, such that during the advancing and navigation of the microcatheter and the delivery tube through the blood vessel, the proximal stopper is free to move distally by the non-zero distance before becoming blocked by the blocking portion. For some of these applications, the non-zero distance between the proximal stopper and the blocking portion is at least 4 mm when the delivery tube is straight.

[0105] For some applications, a distance between the proximal stopper and a proximal end of the lumen is at least 2 mm when the delivery tube is straight. For some applications, a distal end of the delivery tube is disposed within 1 cm of a distal end of the delivery tool, or coincides with the distal end of the delivery tool.

[0106] For some applications, the delivery tube has a length of at least 1 meter.

[0107] For some applications: the delivery tube is configured such that a proximal portion of the tubular wall of the delivery tube is separable from a distal portion of the tubular wall of the delivery tube at a predefined separation border along the tubular wall distal to the blocking portion, and proximally pulling on the pull wire includes: separating the proximal portion of the tubular wall from the distal portion of the tubular wall at the predefined separation border; and moving the proximal portion of the tubular wall proximally such that the blocking portion pushes the proximal stopper proximally, thereby proximally pulling on the pull wire.

[0108] For some of these applications, separating the proximal portion of the tubular wall from the distal portion of the tubular wall at the predefined separation border includes severing the proximal portion of the tubular wall from the distal portion of the tubular wall at the predefined separation border. For some of these applications, the tubular wall is heat- treated at the predefined separation border. Alternatively or additionally, for some of these applications, the tubular wall is scored at the predefined separation border. Further alternatively or additionally, for some of these applications, the tubular wall is perforated at the predefined separation border.

[0109] There is yet additionally provided, in accordance with an application of the present invention, apparatus including An intravascular delivery tool including: a delivery tube, which includes (a) a tubular wall defining a lumen and (b) a blocking insert disposed at least partially within the lumen; and a pull wire, which (a) includes a proximal stopper at a proximal end portion of the pull wire, and (b) is disposed at least partially within the lumen such that the proximal stopper is within the lumen proximal to the blocking insert, wherein the blocking insert is shaped so as to block distal movement of the proximal stopper distally beyond the blocking insert.

[0110] For some applications, the blocking insert includes a tube.

[0111] For some applications, the tube is non-extensible. For some applications, the blocking insert includes a rod.

[0112] For some applications, the blocking insert is welded in place.

[0113] For some applications, the tubular wall of the delivery tube is shaped so as to define one or more welding holes via which the blocking insert is welded in place.

[0114] For some applications, the blocking insert includes a rod that is disposed partially within the lumen and disposed and welded partially within one of the one or more welding holes.

[0115] There is also provided, in accordance with an application of the present invention, a method including: inserting a microcatheter into a blood vessel while an intravascular delivery tool is removably disposed in the microcatheter, and an implant is removably disposed in the microcatheter near a distal end of the intravascular delivery tool, wherein the intravascular delivery tool includes (i) a delivery tube that includes (a) a tubular wall defining a lumen and (b) a blocking insert disposed at least partially within the lumen, and (ii) a pull wire, which (a) includes a proximal stopper at a proximal end portion of the pull wire, and (b) is disposed at least partially within the lumen such that the proximal stopper is within the lumen proximal to the blocking insert, and wherein the blocking insert is shaped so as to block distal movement of the proximal stopper distally beyond the blocking insert; advancing the microcatheter, and the delivery tube removably disposed therein, in the blood vessel; deploying the implant from the microcatheter; and releasing the implant from the delivery tool by proximally pulling on the pull wire.

[0116] For some applications, the blocking insert includes a tube. For some of these applications, the tube maintains a constant length throughout the method.

[0117] For some applications, the blocking insert includes a rod.

[0118] For some applications, the blocking insert is welded in place. For some of these applications, the tubular wall of the delivery tube is shaped so as to define one or more welding holes via which the blocking insert is welded in place. For some of these applications, the blocking insert includes a rod that is disposed partially within the lumen and disposed and welded partially within one of the one or more welding holes.

[0119] The present invention will be more fully understood from the following detailed description of embodiments thereof, taken together with the drawings, in which:

[0120] BRIEF DESCRIPTION OF THE DRAWINGS

[0121] Figs. 1A-D are schematic illustrations of an implant system, in accordance with an application of the present invention;

[0122] Figs. 2A-B are additional schematic illustrations of the implant system of Figs. 1A- D, in accordance with an application of the present invention;

[0123] Fig. 3 is a schematic illustration of another configuration of the implant system of Figs. 1A-D, in accordance with an application of the present invention;

[0124] Figs. 4A-C are schematic illustrations of a method of using the implant system of Figs. 1A-D to treat a vascular malformation, in accordance with an application of the present invention;

[0125] Figs. 5A-C are schematic illustrations of an implant system in respective states, in accordance with an application of the present invention;

[0126] Figs. 6A-C are schematic illustrations of another implant system in respective states, in accordance with an application of the present invention;

[0127] Figs. 7A-C are schematic illustrations of still another implant system in respective states, in accordance with an application of the present invention; and

[0128] Figs. 8A-C are schematic illustrations of yet another implant system in respective states, in accordance with an application of the present invention.

[0129] DETAILED DESCRIPTION OF APPLICATIONS

[0130] Figs. 1A-D are schematic illustrations of an implant system 10, in accordance with an application of the present invention. Implant system 10 comprises an implant 20 and an intravascular delivery tool 22 for delivering implant 20 to a site within a patient, such as described hereinbelow with reference to Figs. 4A-C. Figs. 1 A-D show a portion of implant 20; a full view of one illustrative configuration of implant 20 can be seen in Figs. 4A-C, described hereinbelow. Implant 20 comprises: an implant wire 30, which includes an implant-wire proximal end portion 34 that includes a proximal end 36 of implant wire 30 (labeled in Figs. IB and 2A); and

[0131] • a retention portion 38, which is disposed at proximal end 36 of implant wire 30, and which has as a greatest width W 1 that is greater than a diameter DI of implant- wire proximal end portion 34 (labeled in Fig. IB), the greatest width W1 measured perpendicular to a central longitudinal axis 42 of implant- wire proximal end portion 34 (labeled in Figs. IB and 2A).

[0132] Delivery tool 22 comprises:

[0133] • a delivery tube 50;

[0134] • a tubular tip 52, which is fixed to a distal end 54 of delivery tube 50 (labeled in Fig. IB); and

[0135] • a pull wire 60.

[0136] Tubular tip 52 is shaped so as to define (i) a tubular wall 48 having an inner surface 44 that defines a lumen 46 of tubular tip 52, (ii) a tip distal opening 56, (iii) a lateral window 72, and (iv) a tubular distal portion 58 axially between a distal end 82 of lateral window 72 and tip distal opening 56. Retention portion 38 is removably disposed entirely within lumen 46 of tubular tip 52 (and thus not within lateral window 72).

[0137] For clarity of illustration, tubular tip 52 is shown as transparent in Fig. 1A; in practice, tubular tip 52 typically comprises a non-transparent material, such as metal, e.g., stainless steel.

[0138] Pull wire 60 is removably disposed partially within tubular tip 52, so as to define the following portions:

[0139] • a pull-wire proximal portion 74, which passes through a proximal end 76 of tubular tip 52,

[0140] • a pull- wire distal portion 62, which is disposed at least partially within tubular distal portion 58 so as to effectively reduce an inner diameter ID1 of at least an axial portion of tubular distal portion 58 to be too small for retention portion 38 to pass through, thereby retaining retention portion 38 within tubular tip 52, and

[0141] • a pull-wire intermediate portion 78, which is disposed at least partially within lateral window 72; pull- wire intermediate portion 78 is axially between pull- wire proximal portion 74 and pull-wire distal portion 62, and retention portion 38 is disposed alongside pull-wire intermediate portion 78.

[0142] For some applications, such as shown in Figs. 1A-D (and Figs. 4A-B, described hereinbelow), pull-wire distal portion 62 is removably disposed passing through tip distal opening 56 so as to effectively reduce an inner diameter of tip distal opening 56 to be too small for retention portion 38 to pass through, thereby retaining retention portion 38 within tubular tip 52.

[0143] Reference is still made to Figs. 1A-D, and is additionally made to Figs. 2A-B, which are additional schematic illustrations of implant system 10, in accordance with an application of the present invention. Figs. 1A-D show implant system 10 with pull wire 60 removably disposed partially within tubular tip 52 as described immediately above. Figs. 2A-B show implant system 10 after pull wire 60 has been proximally pulled. Implant system 10 may optionally implement any of the features of implant system 110, 110A, 110B, described hereinbelow with reference to Figs. 5A-C and 6A-C, or any of the features of implant system 210, 210A, 210B, described hereinbelow with reference to Figs. 7A-C and 8A-C.

[0144] Implant system 10 is configured such that proximal pulling (i.e., to the left in the figures) on pull wire 60 allows retention portion 38 to pass through tubular tip 52. The proximal pulling does this by proximally retracting pull wire 60 from tubular distal portion 58 (and tip distal opening 56 of tubular tip 52, in configurations in which pull-wire distal portion 62 is removably disposed passing through tip distal opening 56), thereby allowing retention portion 38 to pass through tip distal opening 56, by increasing the effective available size of tubular distal portion 58 (and tip distal opening 56, in configurations in which pull-wire distal portion 62 is removably disposed passing through tip distal opening 56). This allows release of retention portion 38 (and thus implant 20) from tubular tip 52, such as described hereinbelow with reference to Fig. 4C. (Although pull wire 60 cannot be seen at all in Figs. 2A-B, pull wire 60 may alternatively remain within tubular tip 52 after pull wire 60 has been proximally withdrawn, such as shown in Fig. 4C, described hereinbelow.)

[0145] For some applications, such as shown in the figures, tubular wall 48 defines a complete perimeter 64 of lateral window 72 (labeled in Fig. 1C). Alternatively, tubular wall 48 defines only a partial perimeter of lateral window 72; for example, tubular wall 48 may define a narrow slit between distal end 82 of lateral window 72 and a distal end 84 of tubular tip 52.

[0146] Reference is again made to Figs. 1A-D. As described above with reference to Figs. 1A-D, pull-wire intermediate portion 78 is disposed at least partially within lateral window 72. For some applications, pull-wire intermediate portion 78 does not protrude out of lateral window 72 beyond an outer surface 86 of tubular tip 52; in other words, pull-wire intermediate portion 78 is disposed at least partially within a depth D2 of lateral window 72 (labeled in Fig. IB). (The depth D2 of lateral window 72 equals a thickness of tubular wall 48 in the area surrounding lateral window 72. For example, depth D2 may be on average at least 0.04 mm, no more than 0.1 mm, and / or 0.04 - 0.1 mm, e.g., 0.065 mm.)

[0147] For some applications, retention portion 38 comprises a metal alloy comprising nickel and titanium (e.g., Nitinol).

[0148] For some applications, pull-wire intermediate portion 78 comprises a metal alloy comprising nickel and titanium (e.g., Nitinol). Metal alloys comprising nickel and titanium are more flexible than stainless steel, which allows pull-wire intermediate portion 78 to be disposed at least partially within lateral window 72.

[0149] For some applications, an entirety of pull wire 60 comprises the metal alloy comprising nickel and titanium (e.g., Nitinol). Because Nitinol is ductile, pull wire 60 may elongate if the pull wire comprises only Nitinol. For some of these applications, in order to reduce the elongation of the pull wire:

[0150] • the metal alloy of at least an axial portion (e.g., an entirety) of pull wire 60 further comprises an additional metal to reduce the ductility and thus elongation of the pull wire during pulling. For example, the additional metal may comprise niobium (Nb);

[0151] • pull wire 60 comprises two or more segments that are fixed to one another and comprise different respective materials; and / or

[0152] • at least a portion of pull- wire proximal portion 74 is encased in a tube (for example, comprising stainless steel), which effectively reduces the free length of pull wire 60 that comprises only Nitinol; for example, the portion of the pull wire 60 may be the portion that passes through proximal hypotube catheter shaft 66, described hereinbelow with reference to Fig. IB and / or the portion that passes through distal highly-flexible tube 68, also described hereinbelow with reference to Fig. IB.

[0153] For some applications, lateral window 72 is formed through tubular wall 48 of tubular tip 52 by laser cutting.

[0154] For some applications, retention portion 38 and implant- wire proximal end portion 34 are integral with each other and fabricated from a single piece of material (for example, by balling up a portion of the wire proximal to implant wire 30). Alternatively, retention portion 38 and implant-wire proximal end portion 34 are fabricated from separate respective pieces of material fixed together.

[0155] Typically, tubular tip 52 does not taper toward tip distal opening 56, i.e., tubular tip 52 is cylindrical.

[0156] For some applications, retention portion 38 is spherical, such as shown in the figures. Alternatively, retention portion 38 has another shape, such as cylindrical (and, for example, may be crimped onto implant wire 30) (configuration not shown).

[0157] For some applications in which retention portion 38 is spherical, spherical retention portion 38 has a diameter of at least 0.05 mm, no more than 2 mm, and / or 0.05 - 2 mm, such as 0.05 - 0.3 mm, e.g., 0.15 - 0.25 mm, such as 0.2 mm.

[0158] For some applications in which retention portion 38 is spherical, a greatest width W2 of lateral window 72 (labeled in Fig. 1C) is no more than 90% (e.g., no more than 80%, such as no more than 75%) of a diameter D3 of spherical retention portion 38 (labeled in Fig. IB).

[0159] For some applications, implant system 10 has one or more of the following dimensions:

[0160] • an axial length LI (labeled in Fig. 1C) of lateral window 72 is at least 0.4 mm, no more than 1 mm, and / or 0.4 - 1 mm, e.g., 0.5 - 0.9 mm, e.g., 0.7 mm,

[0161] • the greatest width W2 (labeled in Fig. 1C) of lateral window 72 is at least 0.1 mm, no more than 0.3 mm, and / or 0.1 - 0.3 mm, e.g., 0.15 mm,

[0162] • an axial length L2 (labeled in Fig. IB) of retention portion 38 is at least 0.05 mm, no more than 2 mm, and / or 0.05 - 2 mm, such as 0.05 - 0.3 mm, e.g., 0.15 - 0.25 mm, such as 0.2 mm,

[0163] • a greatest outer diameter OD (labeled in Fig. 1C) of tubular tip 52 is at least 0.15 mm (e.g., at least 0.25 mm), no more than 0.5 mm, and / or 0.15 - 0.5 mm, such as 0.25 - 0.5 mm, e.g., 0.2 mm or 0.36 mm,

[0164] • a greatest inner diameter ID2 (labeled in Fig. IB) of tubular tip 52 is at least 0.15 mm, no more than 0.3 mm, and / or 0.15 - 0.3 mm, e.g., 0.23 mm,

[0165] • the diameter DI of implant- wire proximal end portion 34 is at least 0.05 mm, no more than 0.1 mm, and / or 0.05 - 0.1 mm, e.g., 0.085 mm,

[0166] • the greatest width W1 of retention portion 38 equals at least 125% (e.g., at least 150%, such as at least 200%) of the diameter DI of implant-wire proximal end portion 34,

[0167] • the axial length LI (labeled in Fig. 1C) of lateral window 72 equals at least 150% (e.g., at least 200%, such as at least 300%) of the axial length L2 of retention portion 38 (labeled in Fig. IB),

[0168] • the axial length LI of lateral window 72 equals at least 100% (e.g., at least 150%, such as at least 200%) of the greatest outer diameter OD of tubular tip 52,

[0169] • the axial length LI of lateral window 72 equals at least 200% (e.g., at least 250%, such as at least 300%) of the greatest width W2 of lateral window 72.

[0170] • the greatest width W2 of lateral window 72 is no more than 90% (e.g., no more than 80%, such as no more than 75%) of the greatest width W1 of retention portion 38, and / or

[0171] • pull- wire intermediate portion 78 has a radius of curvature of at least 0.05 mm (e.g., at least 0.5), no more than 20 mm (e.g., no more than 2 mm), and / or 0.05 - 20 mm, such as 0.5 - 2 mm.

[0172] The axial length LI of lateral window 72 may enable a greater radius of curvature of pull- wire intermediate portion 78 than if lateral window 72 were shorter.

[0173] For some applications, such as labeled in Fig. IB, a length L3 of tubular distal portion 58 is (a) no more than 0.1 mm (e.g., equals 0.07 mm), and / or (b) no more than 50% of the axial length L2 of retention portion 38 (e.g., equals 40% of the axial length L2). Providing a relative short length L3 allows a shorter implant-wire proximal end portion 34, which may result in less protrusion of retention portion 38 into a blood vessel, such as shown in Fig. 4C, described hereinbelow. Reference is made to Fig. 3, which is a schematic illustration of another configuration of implant system 10, in accordance with an application of the present invention. In the configuration shown in Fig. 3, pull-wire distal portion 62 is removably disposed entirely within tubular distal portion 58, thereby causing only an axial portion of tubular distal portion 58 to be too small for retention portion 38 to pass through. Thus, unlike in the configurations shown in Figs. 1A-D and 4A-B, in the configuration shown in Fig. 3 pull-wire distal portion 62 does not pass through tip distal opening 56.

[0174] Optionally, as shown in Fig. 3, in configurations in which pull- wire distal portion 62 is disposed entirely within tubular distal portion 58, the length L3 of tubular distal portion 58 is greater than in the configurations shown in Figs. 1A-D and 4A-B. During advancement and re-sheathing in tortuous vasculature, relative movement may occur between the pull wire 60 and delivery tube 50, which may cause a slight proximal retraction of pull wire 60 from its initial axial position, which in turn may prematurely release retention portion 38. The greater length L3 of tubular distal portion 58 may accommodate this unintended proximal retraction of pull wire 60.

[0175] Reference is made to Figs. 4A-C, which are schematic illustrations of a method of using implant system 10 to treat a vascular malformation, such as an aneurysm 100, in accordance with an application of the present invention.

[0176] Before the state shown in Fig. 4A is reached, a guidewire is inserted into a blood vessel 104 and advanced until a distal end of the guidewire is disposed in aneurysm 100. A microcatheter 102 is inserted into blood vessel 104 and advanced over the guidewire until the distal end of the microcatheter is disposed in aneurysm 100. The guidewire is withdrawn and removed from the subject's body, leaving the distal end of the microcatheter in the aneurysm. Delivery tool 22 and implant 20 are inserted into the microcatheter via a proximal end of the microcatheter, such that delivery tool 22 and implant 20 are removably disposed in the microcatheter, with a proximal end of implant 20 removably coupled to tubular tip 52 of delivery tool 22, as described hereinabove with reference to Figs. 1A-D. Delivery tool 22 is used to push implant 20 out of the distal end of microcatheter 102.

[0177] Fig. 4A shows the deployment after implant 20 has been deployed from microcatheter 102 into aneurysm 100, and while the proximal end of implant 20 is still removably coupled to tubular tip 52 of delivery tool 22. Pull-wire distal portion 62 of pull wire 60 passes through tip distal opening 56 so as to effectively reduce a size of tip distal opening 56 to be too small for retention portion 38 to pass through, thereby retaining retention portion 38 within tubular tip 52, as described hereinabove with reference to Figs. 1A-D.

[0178] As shown in Fig. 4C, implant 20 is released from delivery tool 22 by proximally pulling on pull wire 60 (i.e., to the left in the figures) so as to allow retention portion 38 to pass through tubular tip 52, such as described hereinabove with reference to Figs. 2A-B.

[0179] Fig. 4C shows implant 20 deployed in aneurysm 100 after delivery tool 22 and microcatheter 102 have been proximally withdrawn from blood vessel 104. In the particular configuration illustrated in Figs. 4A-C, Fig. 4C shows an orifice section of implant 20 deployed within a portion of aneurysm 100, so as to at least partially cover an orifice 106 of aneurysm 100.

[0180] For some applications, the method further comprises implanting endovascular embolization coils in aneurysm 100, such that the endovascular embolization coils become entangled with an intra-vascular-malformation docking section 112 of implant 20. An orifice section 114 of implant 20 reduces the risk of (typically prevents) coil herniation, i.e., endovascular embolization coils exiting the vascular malformation into the parent vessel, particularly in malformations with a wide opening such as wide-neck aneurysms and / or those located at bifurcations. The anatomy of wide-neck aneurysms often does not allow the aneurysmal sac to retain endovascular embolization coils by itself, and herniating or protruding endovascular embolization coils can cause ischemic stroke.

[0181] Reference is now made to Figs. 1A-D, 2A-B, and 4A-C. In an application of the present invention, implant wire 30 further comprises a coil-wire portion 32 that is distally adjacent to implant-wire proximal end portion 34. Implant 20 further comprises a coil 40, which is coiled around coil-wire portion 32 and not around implant-wire proximal end portion 34. It is emphasized that coil-wire portion 32 and coil 40 are optional, and that in some other configurations implant 20 does not comprise these elements; by way of example and not limitation, implant 20 may comprise an intrasaccular flow disruption device and / or a device comprising a braided wire mesh.

[0182] For some applications, pull wire 60 is removably disposed partially within tubular tip 52 such that pull- wire distal portion 62 passes through tip distal opening 56 and through a portion of coil 40 alongside a portion of coil-wire portion 32 of implant wire 30, such as shown in Figs. 1A-D and 4A-B. For example, a length L6 of the portion of coil- wire portion 32 alongside which pull wire 60 is disposed (labeled in Fig. IB) may be at least 0.1 mm, no more than 5 mm, and / or 0.1 - 5 mm. e.g., 0.3 - 2 mm, such as 0.5 - 0.6 mm. Disposal of pull-wire distal portion 62 alongside the portion of coil-wire portion 32 of implant wire 30 may provide some slack in pull wire 60, which may help accommodate the unintended proximal retraction of pull wire 60 during advancement and re- sheathing in tortuous vasculature, as described hereinabove with reference to Fig. 3.

[0183] For some applications, a proximal end 24 of coil 40 (labeled in Fig. 1C) touches an external distal surface 26 of tubular tip 52.

[0184] For some applications, at least 75% (e.g., at least 90%, such as at least 95%) of a combined length L4 (labeled in Fig. IB) of (a) implant-wire proximal end portion 34 and (b) retention portion 38 is disposed within tubular tip 52. For some of these applications, implant-wire proximal end portion 34 is disposed entirely within tubular tip 52.

[0185] Alternatively or additionally, For some applications, at least 50% (e.g., at least 75%, such as at least 90%, e.g., at least 95%) of a length of implant-wire proximal end portion 34 is disposed within tubular tip 52.

[0186] For some applications, an axial portion of implant-wire proximal end portion 34 is disposed outside and distal to tubular tip 52, the axial portion having a length L5 of less than 0.1 mm (labeled in Fig. IB). Providing this relatively short length L5 allows a shorter implant-wire proximal end portion 34, which may result in less protrusion of retention portion 38 into a blood vessel, such as shown in Fig. 4C, described hereinbelow. This benefit may also be provided by configurations in which proximal end 24 of coil 40 touches external distal surface 26 of tubular tip 52, as described above, in which case the length L5 is effectively equal to zero.

[0187] For some applications, such as labeled in Fig. IB, coil 40 has an outer diameter D4 of at least 300% of a diameter D5 of coil-wire portion 32, no more than 900% of the diameter D6, and / or 300% - 900% of the diameter D6. Alternatively or additionally, for some applications, the outer diameter D4 of coil 40 is at least 0.24 mm, no more than 0.69 mm, and / or 0.24 - 0.69 mm, such as 0.3 - 0.4 mm, e.g., about 0.36 mm.

[0188] Reference is again made to Fig. IB. For some applications, delivery tube 50 comprises a proximal hypotube catheter shaft 66 fixed to a distal highly-flexible tube 68, which is turn is fixed to tubular tip 52. For example, highly-flexible tube 68 may comprise a hollow helical strand (HHS) tube, as shown, a coil (configuration not shown), or a tube having a helical slit (e.g., laser-cut). Distal highly-flexible tube 68 may provide increased flexibility for navigating the tortuosity of the vasculature (e.g., the brain vasculature). Hypotube catheter shafts are commercially available (e.g., from Johnson Matthey Medical Components, West Chester, PA, USA), as are HHS tubes (e.g., from Fort Wayne Metals Research Products Corp., Fort Wayne, IN, USA). Optionally, proximal hypotube catheter shaft 66 and / or distal hollow helical strand (HHS) tube 68 comprise stainless steel.

[0189] Reference is made to Figs. 1A-D, 2A-B, 3, and 4A-C. For some applications, implant 20 is configured to treat a vascular malformation, such as aneurysm 100. For some applications, implant 20 is configured to bridge the neck of a vascular malformation, such as aneurysm 100, e.g., a wide-necked aneurysm, in order to prevent coil herniation. For example, the aneurysm may be a saccular aneurysm formed in the wall of a blood vessel, typically an artery, such as a cerebral aneurysm, a coronary artery aneurysm, a ventricular aneurysm, an aneurysm of the sinus of Valsalva, an aneurysm following cardiac surgery, or an aortic aneurysm. Alternatively, the vascular malformation may be any congenital and / or non-congenital blood vessel abnormality, such as, but not limited to, a fistula, a tumor, or an arteriovenous malformation.

[0190] For some applications, implant 20 comprises an intravascular coil.

[0191] For some applications, implant 20 comprises an orifice section; an intra-vascularmalformation docking section; and a connecting section, and implant 20 is configured such that, when unconstrained, the orifice section is shaped so as to define an orifice- section curve, the intra-vascular-malformation docking section is shaped so as to define a dockingsection curve, and the connecting section connects the orifice-section curve with the docking-section curve. For example, techniques may be used that are described in one or more of the patents and patent applications incorporated by reference hereinbelow.

[0192] (For applications in which implant 20 comprises orifice and intra-vascularmalformation docking sections having orifice- section and docking-section curves, respectively, such as described above, these curves are of a much larger scale than that of coil 40. These larger curves are defined by shaping coil 40 together with coil-wire portion 32 of implant wire 30 into a larger-scale curve. In other words, coil 40 may be considered a primary coil and the curves may be considered secondary coils.)

[0193] Optionally, lateral window 72 may be used during assembly of system 10, such as for pushing pull wire 60 around retention portion 38 and into coil 40 of implant 20. Reference is still made to Figs. 1A-D, 2A-B, 3, and 4A-C. For some applications, delivery tool 22 further comprises a proximal stopper 90, which is disposed within lumen 46 of tubular tip 52 proximal to retention portion 38, so as to prevent proximal motion of retention portion 38 beyond proximal stopper 90. Optionally, proximal stopper 90 is defined by a tab 92 cut from tubular wall 48 and folded inwardly into lumen 46 of tubular tip 52, such as shown. Alternatively, proximal stopper 90 is defined by a separate piece of material inserted into lumen 46 during manufacture, and fixed to inner surface 44 of tubular wall 48.

[0194] Implant 20 may optionally implement any of the techniques described in the patent applications and patent application publications incorporated hereinbelow by reference.

[0195] Reference is now made to Figs. 5A-C, which are schematic illustrations of an implant system 110, 110A in accordance with an application of the present invention.

[0196] Reference is further made to Figs. 6A-C, which are schematic illustrations of another implant system 110, HOB in accordance with an application of the present invention.

[0197] Other than as described hereinbelow, implant systems 110A and 110B are identical.

[0198] Implant system 110, 110A, 110B comprises an implant and an intravascular delivery tool 122, 122A, 122B for delivering the implant to a site within a patient, such as described hereinbelow with reference to Figs. 5C and 6C.

[0199] Implant system 110, 110A, HOB may optionally implement any of the features of implant system 10, described hereinabove with reference to Figs. 1A-D, 2A-B, 3, and 4A- C. Intravascular delivery tool 122, 122A, 122B may optionally implement any of the features of delivery tool 22, described hereinabove with reference to Figs. 1A-D, 2A-B, 3, and 4A-C. Alternatively, implant system 110, 110A, HOB may implement alternative techniques for delivering and releasing an implant from intravascular delivery tool 122, 122A, 122B, respectively. By way of example and not limitation, certain elements of implant system 110, 110A, HOB are described as comprising elements of implant system 10.

[0200] Similarly, the implant may comprise implant 20, described hereinabove with reference to Figs. 1A-D, 2A-B, 3, and 4A-C, or another implant, such as an implant described in the patent applications and patent application publications incorporated hereinbelow by reference. By way of example and not limitation, implant system 110, 110A, HOB is described hereinbelow as delivering and releasing implant 20.

[0201] In some applications of the present invention, intravascular delivery tool 122, 122A, 122B comprises:

[0202] • delivery tube 50, which comprises a tubular wall 53, 53A, 53B defining a lumen 55 and integrally defining a blocking portion 57 that protrudes into lumen 55; and

[0203] • pull wire 60, which (a) comprises a proximal stopper 70 at a proximal end portion 88 of pull wire 60, and (b) is disposed at least partially within lumen 55 such that proximal stopper 70 is within lumen 55 proximal to blocking portion 57.

[0204] Blocking portion 57 is shaped so as to block distal movement of proximal stopper 70 distally beyond blocking portion 57, such as described hereinbelow with reference to Figs. 5C and 6C.

[0205] Blocking portion 57 is integrally defined by tubular wall 53, 53A, 53B in the sense that the blocking portion is defined by material of the tubular wall itself, rather than comprises a separate piece of material disposed within lumen 55. This integral definition may enable a simpler and more repeatable manufacturing process than if a separate piece of material were provided for the blocking portion. For example, in the configuration described hereinbelow with reference to Figs. 5A-C, the one or more indentations 94 may be formed by crimping, e.g., using a crimper, such as a manual crimper, and in the configuration described hereinbelow with reference to Figs. 6A-C, the one or more tabs 96 may be cut from tubular wall 53 using laser cutting.

[0206] For example, proximal stopper 70 may comprise a tube adhered to proximal end portion 88 of pull wire 60. For example, proximal stopper 70, e.g., the tube, may have a length of at least 1 mm, no more than 10 mm, and / or 1 - 10 mm, such as at least 2 mm, no more than 4 mm, and / or 2 - 4 mm, e.g., 3 mm. Alternatively, proximal stopper 70 may have a non-cylindrical shape, such as a sphere. Optionally, pull wire 60 is deformed to integrally define proximal stopper 70.

[0207] Proximal end portion 88 may include a proximal end of pull wire 60 (such as shown), or the proximal end of pull wire 60 may protrude proximally from proximal stopper 70 (configuration not shown).

[0208] Reference is made to Figs. 5A-C. For some applications, blocking portion 57 of implant system 110, 110A comprises a blocking portion 57A that is integrally defined by one or more indentations 94 in tubular wall 53. For example, the one or more indentations 94 may comprise exactly one indentation 94, as shown, or a plurality of indentations 94 distributed evenly or unevenly around an axis of tubular wall 53 (configurations not shown). In configurations in which the one or more indentations 94 comprise exactly one indentation 94, the exactly one indentation 94 may extend around only a portion of an axis of tubular wall 53, as shown, or may extend entirely around (i.e., 360 degrees around) the axis of tubular wall 53 (configuration not shown).

[0209] Reference is made to Figs. 6A-C. For some applications, blocking portion 57 of implant system 110, HOB comprises a blocking portion 57B that is integrally defined by one or more tabs 96 cut from tubular wall 53 (the one or more tabs may be considered one or more flaps). For example, the one or more tabs 96 may comprise exactly one tab 96, as shown, or a plurality of tabs 96 distributed evenly or unevenly around an axis of tubular wall 53 (configurations not shown).

[0210] For some applications, pull wire 60 extends out of a distal end 98 of lumen 55, such as shown. For other applications, a distal end of pull wire 60 is disposed within lumen 55 (configuration not shown).

[0211] Reference is now made to Figs. 5A-B and 6A-B. The advancement and navigation of delivery tube 50 (such as distal highly-flexible tube 68 of delivery tube 50) through tortuous vasculature of the patient may inadvertently cause distal movement of pull wire 60 with respect to blocking portion 57, thereby approximating (bringing closer) proximal stopper 70 and blocking portion 57. This approximation may prematurely proximally pull a distal portion of pull wire 60 and thereby prematurely release implant 20 from intravascular delivery tool 122. In order to prevent this premature release, blocking portion 57 is located at a first non-zero distance D7 from a proximal end 65 of lumen 55 when delivery tube 50 is straight, and proximal stopper 70 is positioned within lumen 55 between blocking portion 57 and proximal end 65 of lumen 55 at at least a second non-zero distance D8 from blocking portion 57 when delivery tube 50 is straight. Thus, as shown in the transitions between Fig. 5 A and Fig. 5B and between Fig. 6A and 6B, during the advancement and navigation of delivery tube 50 through the tortuous vasculature, proximal stopper 70 is free to move distally by second distance D8 before becoming blocked by blocking portion 57 and potentially releasing implant 20 from intervascular delivery tool 122. In addition, it may sometimes be necessary to re-sheath implant 20 into microcatheter 102, such as if implant 20 must be repositioned during the implantation procedure prior to the release of implant 20 from intervascular delivery tool 122. This resheathing is typically performed by pulling on a proximal portion of delivery tube 50 outside the patient's body while holding microcatheter 102 stationary, in order to proximally withdraw delivery tube 50 within microcatheter 102 and proximally pull implant 20 back into microcatheter 102. Sometimes delivery tube 50may elongate slightly during this proximal withdrawal (both distal highly -flexible tube 68 and proximal hypotube catheter shaft 66 may be slightly extensible). This elongation of distal highly -flexible tube 68 by pulling on the proximal portion of delivery tube 50 causes blocking portion 57 to move slightly proximally. The second non-zero distance D8 between proximal stopper 70 and blocking portion 57 prevents blocking portion 57 from proximally reaching proximal stopper 70 and pushing proximal stopper 70 proximally, which might prematurely release implant 20 from intervascular delivery tool 122, such as described hereinbelow with reference to Figs. 5C and 6C.

[0212] In addition, the advancement and navigation of delivery tube 50 (such as distal highly-flexible tube 68 of delivery tube 50) through tortuous vasculature of the patient may inadvertently cause distal movement of delivery tube 50 with respect to proximal stopper 70. In order to prevent blocking portion 57 from exiting proximal end 65 of lumen 55, blocking portion 57 is located at a third non-zero distance D9 from proximal end 65 of lumen 55 when delivery tube 50 is straight.

[0213] For some applications, when delivery tube 50 is straight:

[0214] • first non-zero distance D7 is at least 5 mm, no more than 5,000 mm, and / or 5 mm - 5,000 mm, such as at least 5 mm, no more than 50 mm, and / or 5 - 50 mm, e.g., 15 - 20 mm,

[0215] • second non-zero distance D8 is at least 4 mm, no more than 45 mm, and / or 4 - 45 mm, such 5 - 10 mm, and / or

[0216] • third non-zero distance D9 is at least 2 mm, no more than 40 mm, and / or 2 - 40 mm, such as at least 3, no more than 5 mm, and / or 3 - 5 mm.

[0217] Typically, distal end 54 of delivery tube 50 (labeled in Fig. IB) is disposed within

[0218] 1 cm (e.g., within 0.5 cm) of a distal end 116 of the delivery tool (such as shown in the figures), or coincides with distal end 116 of the delivery tool (labeled in Fig. 4A) (configuration not shown).

[0219] Typically, delivery tube 50 has a length of at least 1 meter.

[0220] Reference is still made to Figs. 5A-B and 6A-B, and is further made to Figs. 4A-C, which are schematic illustration of implant 20 and a distal portion of intravascular delivery tool 22 during a portion of a deployment procedure, in accordance with an application of the present invention. As mentioned above, intravascular delivery tool 122, 122A, and 122B may optionally implement features of intravascular delivery tool 22. The techniques described with reference to Fig. 5 may also be implemented for intravascular delivery tool 222, described hereinbelow with reference to Figs. 7A-C and 8A-C, mutatis mutandis.

[0221] In some applications of the present invention, a method of using implant system 110 to treat a vascular malformation, such as aneurysm 100, is provided, comprising:

[0222] • inserting microcatheter 102 into blood vessel 104 while intravascular delivery tool 122 is removably disposed in microcatheter 102, and implant 20 is removably disposed in microcatheter 102 near distal end 116 of the intravascular delivery tool,

[0223] • advancing microcatheter 102, and delivery tube 50 removably disposed therein, in blood vessel 104;

[0224] • deploying implant 20 from microcatheter 102; and

[0225] • releasing implant 20 from the delivery tool by proximally pulling on pull wire 60.

[0226] Typically, before microcatheter 102 is inserted into blood vessel 104, a guidewire is inserted into blood vessel 104 and advanced until a distal end of the guidewire is disposed in aneurysm 100. Microcatheter 102 is then inserted into blood vessel 104 and advanced over the guidewire until the distal end of microcatheter 102 is disposed in aneurysm 100. The guidewire is withdrawn and removed from the subject's body, leaving the distal end of microcatheter 102 in aneurysm 100. Delivery tool 122 and implant 20 are inserted into microcatheter 102 via a proximal end of microcatheter 102. Delivery tool 122 is used to push implant 20 out of the distal end of microcatheter 102.

[0227] For some applications, the method further comprises implanting endovascular embolization coils in aneurysm 100, such that the endovascular embolization coils become entangled with an intra-vascular-malformation docking section of implant 20, such as described hereinabove with reference to Figs. 4A-C. The method may optionally implement any of the techniques of the method described hereinabove with reference to Figs. 4A-C, mutatis mutandis.

[0228] Reference is now made to Figs. 5A-C and 6A-C. In some applications of the present invention, delivery tube 50 is configured such that a proximal portion 80 of tubular wall 53 of delivery tube 50 is separable from a distal portion 81 of tubular wall 53 of delivery tube 50 at a predefined separation border 83 along tubular wall 53 distal to blocking portion 57. (Typically, proximal portion 80 of tubular wall 53 includes proximal end 65 of lumen 55.)

[0229] For some applications, in the method described hereinabove with reference to Figs. 5A-B and 6A-B, proximally pulling on pull wire 60 comprises:

[0230] • separating proximal portion 80 of tubular wall 53 from distal portion 81 of tubular wall 53 at predefined separation border 83 (during the procedure, proximal portion 80 and a proximal portion of distal portion 81 are disposed outside the patient's body); and

[0231] • moving proximal portion 80 of tubular wall 53 proximally such that blocking portion 57 pushes proximal stopper 70 proximally, thereby proximally pulling on pull wire 60 (blocking portion 57 pushes proximal stopper 70 proximally because blocking portion 57 is shaped so as to block distal movement of proximal stopper 70 distally beyond blocking portion 57, such as described hereinabove).

[0232] For some applications, delivery tube 50 is configured such that proximal portion 80 of tubular wall 53 is severable from distal portion 81 of tubular wall 53 of delivery tube 50 at predefined separation border 83. For example, tubular wall 53 may be heat-treated (which typically weakens the wall at predefined separation border 83), scored, or perforated at predefined separation border 83.

[0233] Reference is now made to Figs. 7A-C, which are schematic illustrations of an implant system 210, 210A in accordance with an application of the present invention.

[0234] Reference is further made to Figs. 8A-C, which are schematic illustrations of another implant system 210, 210B in accordance with an application of the present invention.

[0235] Other than as described hereinbelow, implant systems 210A and 210B are identical with each other, and identical to implant system 110, 110A, HOB described hereinabove with reference to Figs. 5A-C and 6A-C, and may implement any of the features of implant system 110, 110A, HOB, mutatis mutandis.

[0236] Implant system 210, 210A, 21 OB comprises implant 20 and an intravascular delivery tool 222, 222A, 222B for delivering implant 20 to a site within a patient, such as described hereinabove with reference to Figs. 5C and 6C for implant system 110, 110A, HOB.

[0237] Intravascular delivery tool 222, 222A, 222B comprises:

[0238] • a delivery tube 250, which comprises (a) a tubular wall 253, 253A, 253B defining a lumen 255 and (b) a blocking insert 257 disposed at least partially within lumen 255; and

[0239] • pull wire 60, which (a) comprises proximal stopper 70 at proximal end portion 88 of pull wire 60, and (b) is disposed at least partially within lumen 255 such that proximal stopper 70 is within lumen 255 proximal to blocking insert 257.

[0240] Blocking insert 257 is shaped so as to block distal movement of proximal stopper 70 distally beyond blocking insert 257. As described hereinabove with reference to Figs. 5B and 6B for implant system 110, 110A, HOB, intravascular delivery tool 222 is configured to allow proximal movement of proximal stopper 70 proximal to blocking insert

[0241] 257.

[0242] Reference is made to Figs. 7A-C. For some applications, blocking insert 257 of implant system 210, 210A comprises a blocking insert 257A that comprises a blocking tube

[0243] 258. Typically, blocking tube 258 is disposed entirely within lumen 255, typically aligned coaxially with lumen 255. Typically, blocking tube 258 is non-extensible, i.e., has a fixed length and cannot be lengthened during use of implant system 210, 210A.

[0244] Reference is made to Figs. 8A-C. For some applications, blocking insert 257 of implant system 210, 210B comprises a blocking insert 257B that comprises a rod 260.

[0245] Reference is again made to Figs. 7A-C and 8A-C. For some applications, blocking insert 257, 257A, 257B is welded in place. For some of these applications, tubular wall 253, 253A, 253B of delivery tube 250 is shaped so as to define one or more welding holes 262 via which blocking insert 257, 257A, 257B is welded in place.

[0246] Reference is again made to Figs. 8A-C. For some applications in which blocking insert 257B comprises rod 260, rod 260 is disposed partially within lumen 255 and disposed and welded partially within one of the one or more welding holes 262 (for example, tubular wall 253B of delivery tube 250 may be shaped so as to define exactly one welding hole 262, such as shown in Figs. 8A-C). For example, an axis of rod 260 may be oriented perpendicular to an axis of lumen 255.

[0247] Reference is made to Figs. 4A-C, 7A-B, and 8A-B. In some applications of the present invention, a method of using implant system 210 to treat a vascular malformation, such as aneurysm 100, is provided, comprising:

[0248] • inserting microcatheter 102 into blood vessel 104 while intravascular delivery tool 222 is removably disposed in microcatheter 102, and implant 20 is removably disposed in microcatheter 102 near distal end 116 of intravascular delivery tool 222,

[0249] • advancing microcatheter 102, and delivery tube 50 removably disposed therein, in blood vessel 104;

[0250] • deploying implant 20 from microcatheter 102; and

[0251] • releasing implant 20 from delivery tool 222 by proximally pulling on pull wire 60.

[0252] The method may optionally implement any of the techniques of the method described hereinabove with reference to Figs. 5A-B and 6A-B, and / or any of the techniques of the method described hereinabove with reference to Figs. 4A-C, mutatis mutandis.

[0253] Reference is made to Figs. 5C, 6C, 7C, and 8C, which show the implant system after pull wire 60 has been proximally pulled. The implant system is configured such that proximal pulling (i.e., to the left in the figures) on pull wire 60 allows retention portion 38 to pass through tubular tip 52. The proximal pulling does this by proximally retracting pull wire 60 from tubular distal portion 58 (and tip distal opening 56 of tubular tip 52, in configurations in which pull-wire distal portion 62 is removably disposed passing through tip distal opening 56), thereby allowing retention portion 38 to pass through tip distal opening 56, by increasing the effective available size of tubular distal portion 58 (and tip distal opening 56, in configurations in which pull-wire distal portion 62 is removably disposed passing through tip distal opening 56). This allows release of retention portion 38 (and thus implant 20) from tubular tip 52, such as described hereinabove with reference to Figs. 5C and 6C.

[0254] In an embodiment, techniques and apparatus described in one or more of the following applications, which are assigned to the assignee of the present application and incorporated herein by reference, are combined with techniques and apparatus described herein:

[0255] • US Patent 10,595,875 to Mayer et al.

[0256] • US Patent 10,966,728 to Mayer et al.

[0257] • US Provisional Application 62 / 785,013, filed December 26, 2018 • US Provisional Application 62 / 793,532, filed January 17, 2019

[0258] • US Patent Application Publication 2022 / 0087680 to Mayer et al.

[0259] • US Patent Application Publication 2022 / 0087685 to Mayer et al.

[0260] • US Provisional Application 63 / 638,619, filed April 25, 2024

[0261] • US Provisional Application 63 / 699,452, filed September 26, 2024 It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof that are not in the prior art, which would occur to persons skilled in the art upon reading the foregoing description.

Claims

CLAIMS1. An implant system comprising:(a) an implant, which comprises:(i) an implant wire, which includes an implant-wire proximal end portion that includes a proximal end of the implant wire; and(ii) a retention portion, which is disposed at the proximal end of the implant wire, and which has a greatest width that is greater than a diameter of the implant-wire proximal end portion, the greatest width measured perpendicular to a central longitudinal axis of the implant-wire proximal end portion; and(b) a delivery tool, which comprises:(i) a delivery tube;(ii) a tubular tip, which is (A) fixed to a distal end of the delivery tube and (B) shaped so as to define (1) a tubular wall having an inner surface that defines a lumen of the tubular tip, (2) a tip distal opening, (3) a lateral window, and (4) a tubular distal portion axially between a distal end of the lateral window and the tip distal opening, wherein the retention portion is removably disposed entirely within the lumen of the tubular tip; and(iii) a pull wire, which is removably disposed partially within the tubular tip, so as to define the following portions:(A) a pull-wire proximal portion, which passes through a proximal end of the tubular tip,(B) a pull- wire distal portion, which is disposed at least partially within the tubular distal portion so as to effectively reduce an inner diameter of at least an axial portion of the tubular distal portion to be too small for the retention portion to pass through, thereby retaining the retention portion within the tubular tip, and(C) a pull-wire intermediate portion, which is disposed at least partially within the lateral window, wherein the pull-wire intermediate portion is axially between the pull-wire proximal portion and the pull- wire distal portion, and wherein the retention portion is disposed alongside the pull-wire intermediate portion,wherein the implant system is configured such that proximal pulling on the pull wire allows the retention portion to pass through the tubular tip.

2. The implant system according to claim 1, wherein the pull- wire distal portion is removably disposed passing through the tip distal opening so as to effectively reduce an inner diameter of the tip distal opening to be too small for the retention portion to pass through.

3. The implant system according to claim 1, wherein the pull- wire distal portion is removably disposed entirely within the tubular distal portion.

4. The implant system according to claim 1, wherein the tubular wall defines a complete perimeter of the lateral window.

5. The implant system according to claim 1 , wherein the pull- wire intermediate portion does not protrude out of the lateral window beyond an outer surface of the tubular tip.

6. The implant system according to claim 1, wherein the delivery tool further comprises a proximal stopper, which is disposed within the lumen of the tubular tip proximal to the retention portion, so as to prevent proximal motion of the retention portion beyond the proximal stopper.

7. The implant system according to claim 6, wherein the proximal stopper is defined by a tab cut from the tubular wall and folded inwardly into the lumen of the tubular tip.

8. The implant system according to claim 1, wherein the retention portion comprises a metal alloy comprising nickel and titanium.

9. The implant system according to claim 1 , wherein the pull- wire intermediate portion comprises a metal alloy comprising nickel and titanium.

10. The implant system according to claim 1, wherein at least a portion of the pull- wire proximal portion comprises a metal alloy comprising nickel, titanium, and at least one other metal that provides the at least a portion of the pull-wire proximal portion with a ductility less than a ductility of metal alloys that comprise only nickel and titanium.

11. The implant system according to claim 1, wherein at least a portion of the pull- wire proximal portion comprises a metal alloy comprising nickel, titanium, and niobium.

12. The implant system according to claim 1, wherein the tubular wall of the tubular tip comprises stainless steel.

13. The implant system according to claim 1, wherein the retention portion and the implant- wire proximal end portion are integral with each other and fabricated from a single piece of material.

14. The implant system according to claim 1, wherein the retention portion and the implant-wire proximal end portion are fabricated from separate respective pieces of material fixed together.

15. The implant system according to claim 1, wherein the tubular tip does not taper toward the tip distal opening.

16. The implant system according to claim 1, wherein the retention portion is spherical.

17. The implant system according to claim 16, wherein the spherical retention portion has a diameter of 0.05 - 2 mm.

18. The implant system according to claim 16, wherein a greatest width of the lateral window is no more than 90% of a diameter of the spherical retention portion.

19. The implant system according to claim 18, wherein the greatest width of the lateral window is no more than 80% of the diameter of the spherical retention portion.

20. The implant system according to claim 1, wherein an axial length of the lateral window equals at least 150% of an axial length of the retention portion.

21. The implant system according to claim 1, wherein an axial length of the lateral window equals at least 100% of a greatest outer diameter of the tubular tip.

22. The implant system according to claim 21, wherein the axial length of the lateral window equals at least 150% of the greatest outer diameter of the tubular tip.

23. The implant system according to claim 1, wherein an axial length of the lateral window equals at least 200% of a greatest width of the lateral window.

24. The implant system according to claim 1, wherein a greatest width of the lateral window is no more than 90% of the greatest width of the retention portion.

25. The implant system according to claim 24, wherein the greatest width of the lateral window is no more than 80% of the greatest width of the retention portion.

26. The implant system according to claim 1 , wherein the pull- wire intermediate portion has a radius of curvature of at least 0.5 mm.

27. The implant system according to claim 1, wherein a distance between a distal-most point of the lateral window and a distal end of the tubular tip is no more than 0.1 mm.

28. The implant system according to claim 1, wherein a distance between a distal-most point of the lateral window and a distal end of the tubular tip is no more than 50% of an axial length of the retention portion.

29. The implant system according to claim 1, wherein the greatest inner diameter of the tubular tip is 0.15 - 0.3 mm.

30. The implant system according to claim 1, wherein a greatest outer diameter of the tubular tip is 0.15 - 0.5 mm.

31. The implant system according to claim 1 , wherein the greatest width of the retention portion equals at least 125% of the diameter of the implant-wire proximal end portion.

32. The implant system according to any one of claims 1-31, wherein the implant wire further comprises a coil-wire portion that is distally adjacent to the implant-wire proximal end portion, and wherein the implant further comprises a coil, which is coiled around the coil-wire portion and not around the implant-wire proximal end portion.

33. The implant system according to claim 32, wherein the pull wire is removably disposed partially within the tubular tip such that the pull-wire distal portion passes through the tip distal opening and through a portion of the coil alongside a portion of the coil-wire portion of the implant wire.

34. The implant system according to claim 33, wherein a length of the portion of the coil- wire portion alongside which the pull wire is disposed is 0.1 - 5 mm.

35. The implant system according to claim 32, wherein a proximal end of the coil touches an external distal surface of the tubular tip.

36. The implant system according to claim 32, wherein the implant comprises an intravascular coil.

37. The implant system according to claim 32, wherein at least 75% of a combined length of (a) the implant-wire proximal end portion and (b) the retention portion is disposed within the tubular tip.

38. The implant system according to claim 37, wherein at least 90% of the combined length is disposed within the tubular tip.

39. The implant system according to claim 38, wherein the implant-wire proximal end portion is disposed entirely within the tubular tip.

40. The implant system according to claim 32, wherein at least 50% of a length of the implant-wire proximal end portion is disposed within the tubular tip.

41. The implant system according to claim 40, wherein at least 75% of the length of the implant-wire proximal end portion is disposed within the tubular distal tip.

42. The implant system according to claim 32, wherein an axial portion of the implantwire proximal end portion is disposed outside and distal to the tubular distal tip, the axial portion having a length of less than 0.1 mm.

43. A method comprising: inserting a microcatheter into a blood vessel while a delivery tool and an implant of an implant system are removably disposed in the microcatheter, wherein the implant includes (i) an implant wire, which includes an implantwire proximal end portion that includes a proximal end of the implant wire, and (ii) a retention portion, which is disposed at the proximal end of the implant wire, and which has a greatest width that is greater than a diameter of the implant-wire proximal end portion, the greatest width measured perpendicular to a central longitudinal axis of the implant-wire proximal end portion, and wherein the delivery tool includes (i) a delivery tube; (ii) a tubular tip, which is (A) fixed to a distal end of the delivery tube and (B) shaped so as to define (1) a tubular wall having an inner surface that defines a lumen of the tubular tip, (2) a tip distal opening, (3) a lateral window, and (4) a tubular distal portion axially between a distal end of the lateral window and the tip distal opening, wherein the retention portion is removably disposed entirely within the lumen of the tubular tip; and (iii) a pull wire, which is removably disposed partially within the tubular tip, so as to define the following portions: (A) a pull-wire distal portion, which is disposed at least partially within the tubular distal portion so as to effectively reduce an inner diameter of at least an axial portion of the tubular distal portion to be too small for the retention portion to pass through, thereby retaining the retention portion within the tubular tip, and (C) a pull-wire intermediate portion, which is disposed at leastpartially within the lateral window, wherein the pull-wire intermediate portion is axially between the pull- wire proximal portion and the pull- wire distal portion, and wherein the retention portion is disposed alongside the pull-wire intermediate portion; advancing the microcatheter in the blood vessel; deploying the implant from the microcatheter; and releasing the implant from the delivery tool by proximally pulling on the pull wire so as to allow the retention portion to pass through the tubular tip.

44. An intravascular delivery tool comprising: a delivery tube, which comprises a tubular wall defining a lumen and integrally defining a blocking portion that protrudes into the lumen; and a pull wire, which (a) comprises a proximal stopper at a proximal end portion of the pull wire, and (b) is disposed at least partially within the lumen such that the proximal stopper is within the lumen proximal to the blocking portion, wherein the blocking portion is shaped so as to block distal movement of the proximal stopper distally beyond the blocking portion.

45. The intravascular delivery tool according to claim 44, wherein the blocking portion is integrally defined by one or more indentations in the tubular wall.

46. The intravascular delivery tool according to claim 44, wherein the blocking portion is integrally defined by a tab cut from the tubular wall.

47. The intravascular delivery tool according to claim 44, wherein the pull wire extends out of a distal end of the lumen.

48. The intravascular delivery tool according to claim 44, wherein a distance between the blocking portion and a proximal end of the lumen is at least 5 mm when the delivery tube is straight.

49. The intravascular delivery tool according to claim 44, wherein the proximal stopper is positioned within the lumen between the blocking portion and a proximal end of the lumen at at least a non-zero distance from the blocking portion when the delivery tube is straight.

50. The intravascular delivery tool according to claim 49, wherein the non-zero distance between the proximal stopper and the blocking portion is at least 4 mm when the delivery tube is straight.

51. The intravascular delivery tool according to claim 44, wherein a distance between the proximal stopper and a proximal end of the lumen is at least 2 mm when the delivery tube is straight.

52. The intravascular delivery tool according to claim 44, wherein a distal end of the delivery tube is disposed within 1 cm of a distal end of the delivery tool, or coincides with the distal end of the delivery tool.

53. The intravascular delivery tool according to claim 44, wherein the delivery tube has a length of at least 1 meter.

54. The intravascular delivery tool according to any one of claims 44-53, wherein the delivery tube is configured such that a proximal portion of the tubular wall of the delivery tube is separable from a distal portion of the tubular wall of the delivery tube at a predefined separation border along the tubular wall distal to the blocking portion.

55. The intravascular delivery tool according to claim 54, wherein the delivery tube is configured such that the proximal portion of the tubular wall is severable from the distal portion of the tubular wall of the delivery tube at the predefined separation border.

56. The intravascular delivery tool according to claim 55, wherein the tubular wall is heat-treated at the predefined separation border.

57. The intravascular delivery tool according to claim 55, wherein the tubular wall is scored at the predefined separation border.

58. The intravascular delivery tool according to claim 55, wherein the tubular wall is perforated at the predefined separation border.

59. An implant system comprising the intravascular delivery tool according to any one of claims 44-58, the implant system further comprising an implant which is disposed near a distal end of the intravascular delivery tool, wherein the intravascular system is configured such that proximal pulling of the pull wire releases the implant from the intravascular delivery tool.

60. A method comprising: inserting a microcatheter into a blood vessel while an intravascular delivery tool is removably disposed in the microcatheter, and an implant is removably disposed in the microcatheter near a distal end of the intravascular delivery tool, wherein the intravascular delivery tool includes (i) a delivery tube that includes a tubular wall defining a lumen and integrally defining a blocking portion that protrudes into the lumen, and (ii) a pull wire, which (a) includes a proximal stopper at a proximal end portion of the pull wire, and (b) is disposed at least partially within the lumen such that the proximal stopper is within the lumen proximal to the blocking portion, and wherein the blocking portion is shaped so as to block distal movement of the proximal stopper distally beyond the blocking portion; advancing the microcatheter, and the delivery tube removably disposed therein, in the blood vessel; deploying the implant from the microcatheter; and releasing the implant from the delivery tool by proximally pulling on the pull wire.

61. An intravascular delivery tool comprising: a delivery tube, which comprises (a) a tubular wall defining a lumen and (b) a blocking insert disposed at least partially within the lumen; and a pull wire, which (a) comprises a proximal stopper at a proximal end portion of the pull wire, and (b) is disposed at least partially within the lumen such that the proximal stopper is within the lumen proximal to the blocking insert, wherein the blocking insert is shaped so as to block distal movement of the proximal stopper distally beyond the blocking insert.

62. The intravascular delivery tool according to claim 61, wherein the blocking insert comprises a blocking tube.

63. The intravascular delivery tool according to claim 62, wherein the blocking tube is non-extensible.

64. The intravascular delivery tool according to claim 61, wherein the blocking insert comprises a rod.

65. The intravascular delivery tool according to claim 61, wherein the blocking insert is welded in place.

66. The intravascular delivery tool according to claim 65, wherein the tubular wall of the delivery tube is shaped so as to define one or more welding holes via which the blocking insert is welded in place.

67. The intravascular delivery tool according to claim 66, wherein the blocking insert comprises a rod that is disposed partially within the lumen and disposed and welded partially within one of the one or more welding holes.

68. A method comprising: inserting a microcatheter into a blood vessel while an intravascular delivery tool is removably disposed in the microcatheter, and an implant is removably disposed in the microcatheter near a distal end of the intravascular delivery tool, wherein the intravascular delivery tool includes (i) a delivery tube that includes (a) a tubular wall defining a lumen and (b) a blocking insert disposed at least partially within the lumen, and (ii) a pull wire, which (a) includes a proximal stopper at a proximal end portion of the pull wire, and (b) is disposed at least partially within the lumen such that the proximal stopper is within the lumen proximal to the blocking insert, and wherein the blocking insert is shaped so as to block distal movement of the proximal stopper distally beyond the blocking insert; advancing the microcatheter, and the delivery tube removably disposed therein, in the blood vessel; deploying the implant from the microcatheter; and releasing the implant from the delivery tool by proximally pulling on the pull wire.

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