US20140052232A1

US20140052232A1 - Handle assemblies for stent graft delivery systems and associated systems and methods

Info

Publication number: US20140052232A1
Application number: US13/963,912
Authority: US
Inventors: Andrew H. Cragg; John Logan; George Tsai; Nelson Quintana; Mahmood Dehdashtian
Original assignee: Altura Medical Inc
Current assignee: Altura Medical Inc
Priority date: 2012-08-10
Filing date: 2013-08-09
Publication date: 2014-02-20
Also published as: CA2881535A1; CN105050549B; WO2014026173A1; JP6326648B2; EP2882381B1; US20140046429A1; US10285833B2; CN105050549A; EP2882381A1; JP2015524712A; WO2014026173A9; EP2882381A4; AU2013299425A1; US20140046428A1

Abstract

Handle assemblies for stent graft delivery systems and associated methods are disclosed herein. In several embodiments, a handle assembly for a stent graft delivery system includes a movable pushing component configured to deliver a distal portion of the stent graft to an arterial target site. The assembly further includes a moveable pulling component configured to interface with the pushing component and provide a compression force to the distal portion of the stent graft. The stent graft comprises a helix angle and the pulling component is configured to move relative to the pushing component at a ratio corresponding to the helix angle.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to each of the following U.S. Provisional Patent Applications:
(A) U.S. Provisional Patent Application No. 61/681,907, filed on Aug. 10, 2012, and entitled “Handle Assemblies for Stent Graft Delivery Systems and Associated Systems and Methods;” and
(B) U.S. Provisional Patent Application No. 61/799,591, filed Mar. 15, 2013, and entitled “Handle Assemblies for Stent Graft Delivery Systems and Associated Systems and Methods.”
Each of the foregoing applications is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present technology relates to treatment of abdominal aortic aneurysms. More particularly, the present technology relates to handle assemblies for stent graft delivery systems and associated systems and methods.

BACKGROUND

An aneurysm is a dilation of a blood vessel of at least 1.5 times above its normal diameter. The dilated vessel forms a bulge known as an aneurysmal sac that can weaken vessel walls and eventually rupture. Aneurysms are most common in the arteries at the base of the brain (i.e., the Circle of Willis) and in the largest artery in the human body, the aorta. The abdominal aorta, spanning from the diaphragm to the aortoiliac bifurcation, is the most common site for aortic aneurysms. Such abdominal aortic aneurysms (AAAs) typically occur between the renal and iliac arteries, and are presently one of the leading causes of death in the United States.
The two primary treatments for AAAs are open surgical repair and endovascular aneurysm repair (EVAR). Surgical repair typically includes opening the dilated portion of the aorta, inserting a synthetic tube, and closing the aneurysmal sac around the tube. Such AAA surgical repairs are highly invasive, and are therefore associated with significant levels of morbidity and operative mortality. In addition, surgical repair is not a viable option for many patients due to their physical conditions.
Minimally invasive endovascular aneurysm repair (EVAR) treatments that implant stent grafts across aneurysmal regions of the aorta have been developed as an alternative or improvement to open surgery. EVAR typically includes inserting a delivery catheter into the femoral artery, guiding the catheter to the site of the aneurysm via X-ray visualization, and delivering a synthetic stent graft to the AAA via the catheter. The stent graft reinforces the weakened section of the aorta to prevent rupture of the aneurysm, and directs the flow of blood through the stent graft away from the aneurismal region. Accordingly, the stent graft causes blood flow to bypass the aneurysm and allows the aneurysm to shrink over time.
In some systems, braided stent grafts are delivered in an elongated state. Upon delivery from a delivery catheter, the stent graft will elastically shorten into its free state. In other words, the effective length of the stent graft changes as its diameter is forced smaller or larger. For example, a stent graft having a shallower, denser helix angle will result in a longer constrained length. Once the stent graft is removed from a constraining catheter, it can elastically return to its natural, free length.
Delivering a stent graft to an artery requires precise alignment of the distal edge of the stent graft relative to a target location in the destination artery. For example, a misplaced stent graft can block flow to a branching artery. Some stent graft delivery systems utilize one or more markers (e.g., radiopaque markers) to establish the alignment of the stent graft distal edge relative to the artery wall. However, the location of the radiopaque markers on the stent graft can move relative to an initial marker position because of the change in the stent graft's effective length upon delivery, as described above. Accordingly, the stent graft will be deployed, but a distal edge of the stent graft may miss the target point in the artery. Therefore, there exists a need for improved and reliable placement of stent grafts.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of a stent graft delivery system configured in accordance with an embodiment of the present technology.

FIG. 2 is a partially transparent, isometric view of a portion of a handle assembly system having dual lead screws configured in accordance with an embodiment of the present technology.

FIG. 3 is an isometric view of a nested twin rack-and-pinion model of a portion of a handle assembly configured in accordance with embodiments of the present technology.

FIG. 4 is an isometric view of a handle assembly configured in accordance with embodiments of the present technology.

FIG. 5 is an isometric view of a handle assembly configured in accordance with further embodiments of the present technology.

FIG. 6 is an isometric view of a handle assembly configured in accordance with still further embodiments of the present technology.

FIG. 7 is a set of illustrations of collet portions of handle assemblies configured in accordance with embodiments of the present technology.

FIG. 8A is an isometric, partial cut-away view of a handle assembly configured in accordance with another embodiment of the technology. FIG. 8B is an exploded, isometric view of the handle assembly of FIG. 8A.

FIG. 9A is an isometric view of a handle assembly configured in accordance with another embodiment of the technology. FIG. 9B is an isometric, partial cut-away view of the handle assembly of FIG. 9A. FIG. 9C is an exploded, isometric view of the handle assembly of FIG. 9A.

FIG. 10 is an exploded, isometric view of a handle assembly configured in accordance with another embodiment of the technology.

FIGS. 11-16 illustrate handle assemblies or components of handle assemblies configured in accordance with further embodiments of the technology.

FIGS. 17A-17C are isometric views of reverse deployment handle assemblies configured in accordance with embodiments of the technology.

FIG. 18A is a partial cut-away view of a handle assembly for a stent graft delivery system configured in accordance with yet another embodiment of the technology.

FIG. 18B is an enlarged partial cut-away view of travel lead screws of the handle assembly of FIG. 18A configured in accordance with an embodiment of the technology.

FIG. 18C is a side view of housing features that drive linear movement of the travel lead screws of FIG. 18B in accordance with an embodiment of the present technology.

FIG. 18D is an enlarged view of a distal portion of the handle assembly of FIG. 18A configured in accordance with an embodiment of the present technology.

FIG. 18E is a side view of two lead screws with different pitches for use with the handle assembly of FIG. 18A.

DETAILED DESCRIPTION

The present technology is directed toward handle assemblies for stent graft delivery systems and associated systems and methods. In several embodiments, for example, a handle assembly for a stent graft delivery system can include a movable pushing component configured to deliver a distal portion of the stent graft to an arterial target site, and a movable pulling component configured to interface with the pushing component and provide a compression force to the distal portion of the stent graft. The stent graft can include, for example, a helix angle and the pulling component may be configured to move relative to the pushing component at a ratio corresponding to the helix angle.
Certain specific details are set forth in the following description and in FIGS. 1-18E to provide a thorough understanding of various embodiments of the technology. For example, many embodiments are described below with respect to the delivery of stent grafts that at least partially repair AAAs. In other applications and other embodiments, however, the technology can be used to repair aneurysms in other portions of the vasculature. Other details describing well-known structures and systems often associated with stent grafts and associated delivery devices and procedures have not been set forth in the following disclosure to avoid unnecessarily obscuring the description of the various embodiments of the technology. Many of the details, dimensions, angles, and other features shown in the Figures are merely illustrative of certain embodiments of the technology. For example, dimensions shown in the Figures are representative of particular embodiments, and other embodiments can have different dimensions. A person of ordinary skill in the art, therefore, will accordingly understand that the technology may have other embodiments with additional elements, or the technology may have other embodiments without several of the features shown and described below with reference to FIGS. 1-18E.
In this application, the terms “distal” and “proximal” can reference a relative position of the portions of an implantable stent graft device and/or a delivery device with reference to an operator. Proximal refers to a position closer to the operator of the device, and distal refers to a position that is more distant from the operator of the device. Also, for purposes of this disclosure, the term “helix angle” refers to an angle between any helix and a longitudinal axis of the stent graft.
FIG. 1 is an isometric view of a stent graft delivery system 100 (“delivery system 100”) configured in accordance with an embodiment of the present technology. The delivery system 100 can include an outer sheath 150, a distal delivery component 154, and a stent cover 152. During assembly of the delivery system 100, a stent graft (not shown) can be held in place at both its proximal and distal end portions by the outer sheath 150 and the distal delivery component 154, respectively. The outer sheath 150 and the distal delivery component 154 can be referred to collectively as the delivery device. The distal delivery component 154 can include a distal outer sheath (not shown) configured to cover a distal portion of the stent graft and/or a central wire 156 positioned through the stent graft to navigate the vasculature and/or manipulate the distal outer sheath. In several embodiments, the stent graft includes a marker (e.g., a radiopaque marker) to establish alignment of the stent graft with a desired position relative to an arterial wall.
A handle assembly 110 at a proximal portion of the delivery system 100 can be used to controllably release the stent graft from the outer sheath 150. In several embodiments of the present technology, the handle assembly 110 is configured deliver the stent graft in a manner as to keep the initial marker positions relative to the arterial wall from changing upon final stent graft deployment. In several embodiments the stent graft can be delivered with a “push/pull” stroke of the handle assembly 110 during delivery. The proximal portion of the stent graft can be pushed out of the sheath 150 in a traditional manner, while simultaneously the distal end of the stent graft can be axially compressed. The net effect is that during the deployment of the stent graft, the pushing and pulling results in a net zero migration of the marker. There is a natural ratio between the amount of pull for every length of push. In various embodiments, different stent graft diameters, helix angles, and geometry may require different optimum push to pull ratios. In some embodiments, the handle assembly 110 can comprise a “double helix”, that provides for both unsheathing and resheathing a stent without having to swap handles.
As will be described in further detail below, the handle assembly 110 can incorporate various mechanisms to achieve the desired push to pull ratio. In several of the embodiments described below, these mechanisms maintain the axial position of the deployed portion of the stent graft by synchronizing the action of pulling back the sheath 150 simultaneous with pushing the stent graft forward. When the ratio of these actions are matched to or correspond to the helix angle of the braided stent graft, the deployed stent graft will be stationary relative to a destination artery target location.
FIGS. 2-17C illustrate various embodiments of handle assemblies or portions of handles assemblies that effect the push-pull movement described above. FIG. 2, for example, is a partially transparent, isometric view of a portion of a handle assembly 210 configured in accordance with an embodiment of the present technology. The handle assembly 210 includes a first lead screw 212 having a first pitch and a second lead screw 214 having a second pitch different from the first pitch. For further example, FIG. 14 illustrates a close-up view of lead screws having differing pitches. Referring again to FIG. 2, the lead screws 212, 214 are placed adjacent to and engaged with a lead shaft 216. The two lead screws 212, 214 can have threads with opposing pitch, such that when they are both engaged with the shaft 216, a clockwise or counterclockwise rotation of the shaft 216 will cause the lead screws 212, 214 to provide axial translation in opposite directions. When these lead screws 212, 214 are connected to a deployment catheter tube, the desired push/pull delivery of a stent graft can be achieved. For example, one screw (e.g., the first lead screw 212) can be coupled to a first end of the stent graft to provide a compression force while the other screw (e.g., the second lead screw 214) can be coupled to a second end of the stent graft to provide an elongation force. In this embodiment, the lead screws 212, 214 do not rotate, but translate axially as the shaft 216 is twisted. In some embodiments, the handle assembly 210 may also include a keyway spline that engages an axial groove in the threaded lead screws 212, 214. In still other embodiments, the handle assembly 210 may have a different arrangement and/or include different features.
FIG. 3 is an isometric view of a portion of a handle assembly 310 that includes a series of co-axial, nested racks 312 and pinions 314 that can be connected directly to catheters that push and pull a stent graft (not shown) to deliver the graft. In this embodiment, for example, a handle component (not shown) can be rotated and the rotational motion can be translated through gearing to the series of racks 312, such that the same rotation causes one rack 312 to move in a distal direction to push the stent graft out of the delivery catheter. Simultaneously, a second rack 312 is configured to move in a proximal direction to provide a compression force at the distal end of the stent graft. Alternatively, one tube could be manually driven and the rack and pinion mechanism could passively drive the opposing tube elements at the proper ratio, thus requiring no twisting motion. In still other embodiments, the handle assembly 310 may include other features and/or have a different arrangement.
FIG. 4 is an isometric, partial cut-away view of a handle assembly 410 configured in accordance with another embodiment of the technology. The handle assembly 410 comprises a housing 412 through which a guidewire 414 and contrast/flush lumen 416 axially extend. The handle assembly 410 includes an unsheathing screw 418 coaxially surrounded by a position compensating screw 420. The unsheathing screw 418 and position compensating screw 420 can have interfacing threads with different, opposing pitches, such that when the unsheathing screw 418 is rotated to push a proximal end of a stent graft from a catheter, the position compensating screw 420 provides a compensating compression force at a distal end of the stent graft.
The stent can be incrementally deployed/unsheathed with a “jackhammer” type motion. The incremental deployment provides the stent with an opportunity to gradually reshape. For example, the stent can comprise shape-memory material such as Nitinol. The stent can be straightened within the sheath for delivery, and then incrementally reshaped to its natural state upon deployment. The incremental reshaping allows a practitioner to partially deploy the stent, reposition the stent as necessary to best interface with the vasculature, and then fully deploy, allowing the stent to fully resume its natural state shape. A further example of this incremental deployment “jackhammer” feature is illustrated as a slider mechanism shown in FIGS. 11 and 12. As shown in FIGS. 13 and 16, in some embodiments, the jackhammer feature can include a tip-release screw configured to release the stent tip after the stent is in a compressed state; the tip-release screw can prevent accidental deployment by pushing.
FIG. 5 is an isometric, partial cut-away view of a handle assembly 510 configured in accordance with another embodiment of the technology. The handle assembly 510 includes a housing 512 surrounding an unsheathing screw 518 coaxially surrounded by a position compensating screw 520. The unsheathing screw 518 and position compensating screw 520 can have interfacing threads with different, opposing pitches, such that when the unsheathing screw 518 is rotated to push a proximal end of a stent graft from a catheter, the position compensating screw 520 provides a compensating compression force at a distal end of the graft. The handle assembly 510 can allow for partial/incremental deployment of a stent in the manner described above with reference to FIG. 4.
FIG. 6 is an isometric, partial cut-away view of a handle assembly 610 configured in accordance with another embodiment of the technology. The handle assembly 610 includes a housing 612 surrounding an unsheathing screw 618 coaxially surrounded by a position compensating screw 620. The unsheathing screw 618 and position compensating screw 620 can have interfacing threads with different, opposing pitches, such that when the unsheathing screw 618 is rotated to push a proximal end of a stent graft from a catheter, the position compensating screw 620 provides a compensating compression force at a distal end of the graft.
FIG. 7 illustrates various collet portions 710 a-710 e (referred to collectively as “collets 710”) of handle assemblies in accordance with embodiments of the technology. In several embodiments, a handle assembly includes a central lumen through which a push/pull wire or a guidewire extends. The lumen can include a leading collet (e.g., collet 710 a-710 c) at a distal portion of the handle assembly or a trailing collet (e.g., collet 710 d, 710 e) at a proximal portion of the handle assembly. The collets 710 can have various features to improve deliverability of a stent graft. For example, a collet can include an angled tip (e.g., collet 710 a or collet 710 d) or a 5-point angled tip (e.g., collet 710 b) to direct wire path, a rounded tip (e.g., collet 710 c) to eliminate friction/catching, or a spring (e.g., a plastic spring on collet 710 e) to push out wires during graft deployment. While the collets 710 illustrated in FIG. 7 have been designated as “leading” or trailing”, in other embodiments an individual collet may have alternate placement on a handle assembly.
FIG. 8A is an isometric, partial cut-away view of a handle assembly 810 configured in accordance with another embodiment of the technology. FIG. 8B is an exploded, isometric view of the handle assembly 810. Referring to FIGS. 8A and 8B together, the handle assembly 810 includes a housing 812 surrounding an unsheathing screw 818 at least partially coaxially surrounded by, or interfacing with, a position compensating screw 820. The unsheathing screw 818 and position compensating screw 820 can have interfacing threads with different, opposing pitches, such that when the unsheathing screw 818 is rotated to push a proximal end of a stent graft from a catheter, the position compensating screw 820 provides a compensating compression force at a distal end of the graft.
FIG. 9A is an isometric view of a handle assembly 910 configured in accordance with another embodiment of the technology. FIG. 9B is an isometric, partial cut-away view of the handle assembly 910. FIG. 9C is an exploded, isometric view of the handle assembly 910. Referring to FIGS. 9A-9C together, the handle assembly 910 includes several features generally similar to the handle assemblies described above. The handle assembly 910 further includes a ratcheting system 930 configured to instigate interfacing movement of an unsheathing screw 918 and a position compensating screws 920. The ratchet system 930 can operate by a compression or twisting movement. In some embodiments, the ratchet system can provide tactile and/or auditory feedback (e.g., a “click” upon torquing).
FIG. 10 is an exploded, isometric view of a handle assembly 1010 configured in accordance with another embodiment of the technology. The handle assembly 1010 includes several features generally similar to the handle assemblies described above. The handle assembly 1010 includes ratcheting system components 1030, 1032 configured to torque an unsheathing screw 1018 interfaced with a position compensating screws 1020 in the manner described above. The ratchet system can operate by a compression or twisting movement. In some embodiments, the ratchet system provides a tactile and/or auditory feedback (e.g., a “click” upon torquing).
The handle assembly 1010 further includes a seal (e.g., a silicon disc) 1036 configured to block blood or other fluid from traveling into the handle assembly 1010. The seal 1036 accordingly can prevent contamination and/or malfunction of the handle assembly 1010. In further embodiments, the seal 1036 can comprise other biocompatible materials. FIG. 15 illustrates another embodiment of a seal.
FIGS. 11-16 illustrate additional handle assemblies or components of handle assemblies configured in accordance with embodiments of the technology. The handle assemblies illustrated in FIGS. 11-16 can include several features discussed above with reference to FIGS. 1-10, and can further include features such as a thin, ergonomic profile which allows a user's hands to naturally fall into the thinnest sections of the handle. While the handle assemblies described above with reference to FIG. 1-16 include various configurations of screws, ratchets, racks-and-pinions, and other mechanisms, further embodiments can include additional or alternate features to control stent graft length during delivery. For example, in further embodiments, the push and pull forces can be driven by pneumatic or fluidic drives (e.g., push/pull pistons), strings or cable drives, metal or plastic bands, or metal or plastic belts wound against “drums”.
FIGS. 17A-17C are isometric views of reverse deployment handle assemblies 1710 a-1710 c (collectively handle assemblies 1710) configured in accordance with additional embodiments of the technology. Referring to FIGS. 17A-17C together, the handle assemblies 1710 include several features of the handle assemblies described above with reference to FIGS. 1-16. In some embodiments, for example, the handle assemblies 1710 can be configured to provide single-action stent graft deployment via unsheathing. As described above, the handle assemblies 1710 can employ synchronized push and compression forces to prevent implant movement during deployment. In some embodiments, these push and compression forces are effected by one or more rotation cuffs 1740 on the exterior of the handle assemblies 1710. In further embodiments, the handle assemblies 1710 can have one or more lockable positions to control placement and/or compression of the stent graft. By utilizing this synchronized deployment action, less mechanical force may be required as compared to traditional systems.
In some embodiments, the handle assemblies 1710 can deploy the stent graft using a lead screw to facilitate placement, and can accurately and smoothly deliver the stent graft without requiring an outer sheath or external screws on the handle assemblies 1710. In additional embodiments, the handle assemblies 1710 can, further include a tip-release screw configured to control the release of the stent tip. The handle assemblies 1710 may also include audio feedback during unsheathing (e.g., “clicks” upon rotation of one or more of the handle assembly rotation cuffs 1740 or other suitable audio feedback mechanisms). The handle assemblies 1710 can further include a disengageable anti-rotation feature for re-docking or ease of sheath withdrawal. Contrast can be delivered via a system internal to the handle assemblies 1710 or via an introducer sheath. In still further embodiments, contrast can be delivered via other systems or mechanisms. In some embodiments, the mechanics of the handle assemblies 1710 make them easy to disassemble, e.g., in 15 seconds or less.
In further aspects of the technology, stent graft delivery systems can be configured to continuously or simultaneously deploy and expand a stent graft at a treatment site, as opposed to the incremental deployment provided by the “jackhammer” type movement discussed above. In this embodiment, the exposure of the stent graft from the sheath is synchronized with a forced diametric expansion of the stent graft (i.e., the stent graft is expanded as it is exposed). As discussed in further detail below, in some embodiments the simultaneous deployment and expansion of the stent graft is expected to enhance a clinical operator's ease of use.
FIG. 18A, for example, is a partial cut-away view of a handle assembly 1810 of a stent graft delivery system configured to provide continuous and/or simultaneous stent graft deployment and expansion in accordance with an embodiment of the present technology. The handle assembly 1810 can include four main sections: (1) a stationary forward handle 1, a rotating unsheathing center handle 2 (“the rotating handle 2”), a repositioning ring 3, and a tip-release slider 4. The handle assembly 1810 is expected to eliminate the need to manually compensate for stent shortening that occurs as a result of the braided nature of a stent frame, and is also expected to enhance the accuracy with which stents can be placed within a vessel. For example, the handle assembly 1810 is expected to eliminate the need for the position compensating screws described above.
The handle assembly 1810 can include a housing 1812, two lead screws (identified individually as a first lead screw 1850 a and a second lead screw 1850 b, and referred to collectively as lead screws 1850) within the housing 1812. The first and second lead screws 1850 a and 1850 b can be configured to travel in opposite directions at a selected fixed ratio (e.g., a pre-selected fixed ratio) that reduces (e.g., minimizes) movement of the stent at a target site during unsheathing to compensate for the stent transforming from a constrained state to its original expanded state. As shown in FIG. 18D, the first travel lead screw 1850 a can be in mechanical communication with an outer sheath (e.g., via a coupling 1854) to enable longitudinal translation of the outer sheath for unsheathing and exposing the stent graft (not shown). The second travel lead screw 1850 b can be in mechanical communication with a dilator that can longitudinally advance the stent graft within the vasculature.
Referring back to FIG. 18A, the handle assembly 1810 can also include an internal lead screw 1858 positioned to be rotated by the clinical operator to deploy the stent. For example, the internal lead screw 1858 can include a first engagement section and a second engagement section for engaging the first and second travel lead screws 1850 a and 1850 b, respectively. The internal lead screw 1858 may have a first pitch at the first engagement section and a second pitch different from the first pitch (e.g., a finer pitch) at the second engagement section. The first and second pitches of the internal lead screw 1858 may have opposing pitch angles (e.g., one having a left-hand pitch and the other having right-hand pitch) so that the first and second travel lead screws 1850 a and 1850 b move in opposite longitudinal directions upon rotation of the internal lead screw 1858 by the operator (e.g., via the rotating handle 2), thereby providing simultaneous advancement of the stent graft (via the second travel lead screw 1850 b) and retraction of the outer sheath (via the first travel lead screw 1850 a). FIG. 18C illustrates suitable features 1860 (e.g., protrusions) on the interior of the housing 1812 for driving linear movement of the travel lead screws 1850 when the housing 1812 is rotated. In other embodiments, however, the internal lead screw 1858, first and second travel lead screws 1850 a and 1850 b, and/or the features 1860 may have different arrangements and/or include different features.
FIG. 18B is an enlarged side view of the first and second travel lead screws 1850 a and 1850 b of the handle assembly 1810 of FIG. 18A. As discussed above, the first travel lead screw 1850 a can be mechanically coupled to the outer sheath (e.g., as best seen in FIG. 18D) to control unsheathing of the stent, and the second travel lead screw 1850 b can advance the stent as it transforms from an elongated delivery state to an expanded deployed state. The rate of unsheathing the stent graft and advancing the stent graft is determined by the ratio of movement between the first and second travel lead screws 1850 a and 1850 b, which is defined by the pitch or frequency of the first and second engagement sections of the internal lead screw 1858. A course pitch, for example, will result in a higher rate of longitudinal translation compared to a fine pitch. The screw pitch and the resultant motion rate can be selected or, optionally, predefined to control the deployed stent length and diameter. In certain embodiments, for example, the stent may have a delivery state in which it is elongated approximately 100% when loaded into the outer sheath. Therefore, when the rate of retraction of the outer sheath is equal to the rate of advancing/pushing the stent (e.g., via a dilator), the 1:1 movement results in a deployment stent that is expanded to its original (i.e., uncompressed) length and diameter. Reducing the rate of stent advancement to less than the rate of outer sheath retraction results in a lengthened stent with a reduced diameter. In this manner, when the stent graft is elongated by approximately 100% in its delivery state, the diameter and length of the deployed stent can be controlled and predicted based on the “payout” ratio of (1) the rate of outer sheath retraction to (2) the rate of stent advancement/push out.
Clinical evidence has shown that a payout ratio of about 1.5:1 results in a fully appositioned device with clinically and therapeutically appropriate length and diameter. Payout ratios ranging from about 1:1 to about 2:1 have also been shown to provide acceptable stent deployment. In other embodiments, the payout ratio may be higher or lower depending upon various clinical and/or anatomical considerations. A desired payout ratio can be achieved by coursing the pitch frequency of the first engagement section relative to the pitch frequency of the second engagement section at a degree proportional with the desired payout ratio.
In addition, in further aspects of the technology, the handle assembly 1810 can include features that reduce the likelihood (e.g., prevent) unintentional or undesired rotation of the internal screw, which may occur when the rotating handle 2 of the handle assembly 1810 is turned by the operator. For example, one or both of the travel lead screws 1850 can include a slot or recess 1856 that travels along a spine in the forward handle 1 to avoid rotation of the travel lead screws 1850 as the rotating handle 2 is turned by the operator.
FIG. 18E is a side view of two travel lead screws (identified individually as a first travel lead screw 1851 a and a second travel lead screw 1851 b, and referred to collectively as travel lead screws 1851) with different pitches for use with the handle assembly 1810 of FIG. 18A in accordance with embodiments of the technology. More specifically, the first travel lead screw 1851 a has a courser pitch than the second travel lead screw 1851 b. In other embodiments, the handle assembly of FIG. 18A can include travel lead screws having coarser or finer pitches than those illustrated in FIGS. 18A and 18E to provide a desired rate of longitudinal translation.
In operation, the handle assembly 1810 described with reference to FIGS. 18A-18E can provide simultaneous coordinated stent deployment by continuously/simultaneously unsheathing and expanding a stent graft. For example, the handle assembly 1810 is configured to provide a fixed ratio for deployment that occurs automatically via manipulation of the rotating handle 2 to enable automated sheath retraction and stent advancement, which results in continuous/simultaneous deployment of the stent graft. In certain embodiments, the handle assembly 1810 can be adapted to allow a clinical operator to pre-select a desired payout ratio based on various clinical and/or anatomical considerations. The continuous/simultaneous deployment reduces (e.g., eliminates) the risk of neck down sections along the stent, which can occur during the process of manually exposing a segment of the stent followed by compression to expand the stent. In addition, the configuration of the screws (e.g., the travel lead screws 1850 and the internal lead screw 1858) in the handle assembly 1810 is expected to reduce the necessary force applied during stent deployment. Furthermore, the handle assembly 1810 may be controlled by rotation force, thereby reducing the likelihood of linear motion that could lead to position failure. During stent deployment, for example, the clinical operator can keep one hand fixed in place on the handle assembly 1810 and, therefore, the operator does not need to make adjustments to hand positioning during the procedure that could result in unintended axial translation. Accordingly, the handle assembly 1810 is expected to provide improved axial positioning as compared with conventional devices. This ease of stent deployment provided by the handle assembly 1810 may allow the clinical operator to remain focused on a monitor (e.g., in a catheterization lab) during deployment because there is no need to look down at the handle assembly 1810.
In some embodiments, a handle assembly configured in accordance with the present technology may include a communicating system to the paired device (e.g., via wire, RF link, magnetic link, etc.) to help ensure that speed and/or rate of change are uniform during initial through final treatment of the device function. This feature may be configured to be engaged/disengaged based upon the physician's/user's preference. One feature of this arrangement is to provide harmonization relating to the delivery of the intended implant during the procedure with more than one physician/user interfacing with the device(s).

ADDITIONAL EXAMPLES

1. A handle assembly for a stent graft delivery system, the handle assembly comprising:

- a movable pushing component configured to deliver a distal portion of the stent graft to an arterial target site; and
- a moveable pulling component configured to interface with the pushing component and provide a compression force to the distal portion of the stent graft, wherein
  - the stent graft comprises a helix angle, and
  - the pulling component is configured to move relative to the pushing component at a ratio corresponding to the helix angle.

2. The handle assembly of example 1 wherein the pushing component comprises a first rack and pinion and the pulling component comprises a second rack and pinion configured to interface with the first rack and pinion.
3. The handle assembly of example 1 wherein the pushing component comprises a first lead screw coupled to a rotatable shaft and having a first thread pitch, and wherein the pulling component comprises a second lead screw coupled to the shaft and having a second thread pitch different from the first thread pitch.
4. The handle assembly of example 1, further comprising a lumen extending axially through the handle assembly and configured to carry contrast or other fluid.
5. A reverse deployment handle assembly for a stent graft delivery system, the handle assembly comprising:

- a movable delivery component configured to deliver a distal portion of the stent graft to an arterial target site, wherein the delivery component employs synchronized push and compression forces on the stent graft; and
- a rotation cuff on an exterior portion of the handle assembly, wherein the rotation cuff is interfaced with the delivery component and configured to activate the synchronized push and compressions forces.

6. The handle assembly of claim 5 wherein the rotation cuff is rotatably movable into one or more lockable positions configured to control incremental placement of the stent graft.
7. The handle assembly of claim 6 wherein the rotation cuff is configured to provide audio feedback upon placement into the lockable positions.
8. The handle assembly of claim 5, further comprising a lead screw coupled to the movable delivery component and configured to facilitate placement of the stent graft.
9. The handle assembly of claim 5, further comprising a lumen extending axially through the handle assembly and configured to carry contrast or other fluid.
10. A handle assembly for a stent graft delivery system, the handle assembly comprising:

- a threaded unsheathing screw;
- a threaded position compensating screw interfaced with the unsheathing screw; and
- a ratchet system configured to torque the unsheathing screw and the position compensating screw.

11. The handle assembly of claim 10 wherein the unsheathing screw comprises threads of a first pitch and the position compensating screw comprises threads of a second pitch, and wherein the second pitch is different from and opposing the first pitch.
12. The handle assembly of claim 10 wherein the handle assembly comprises ergonomic contours.
13. A stent graft delivery system, comprising:

- a handle for housing, advancing ,and unsheathing a stent graft, wherein the handle comprises an internal lead screw engaged with a first travel lead screw and a second travel lead screw,
- wherein the first travel lead screw is mechanically coupled to a sheath covering the stent graft, and wherein the second travel lead screw is mechanically coupled to the stent graft via a dilator,
- wherein the first travel lead screw and second travel lead screw have opposing pitch angles such that rotation of the internal lead screw causes longitudinal translation of the sheath and stent graft in opposing directions, and
- wherein the first travel lead screw and second travel lead screw have pitch frequencies that enable opposing longitudinal translation of the sheath and stent graft at a predetermined payout ratio.

14. A handle assembly for housing, advancing, and unsheathing a stent graft, the housing assembly comprising:

- a first travel lead screw configured to be mechanically coupled to a sheath covering the stent graft;
- a second travel lead screw configured to be mechanically coupled to the stent graft via a dilator; and
- an internal lead screw engaged with the first and second travel lead screws,
- wherein the first and second travel lead screws have opposing pitch angles such that rotation of the internal lead screw causes longitudinal translation of the sheath and stent graft in opposing directions, and
- wherein the first and second travel lead screws have pitch frequencies that enable opposing longitudinal translation of the sheath and stent graft at a predetermined payout ratio.

The handle assemblies shown and described herein offer several advantages over previous devices. For example, the handle assemblies provide for straightforward delivery of a stent graft to an artery while maintaining initial stent graft marker positions relative to a destination arterial wall. Embodiments employing opposing screws provide a user with the ability to deliver a stent graft at a high force with relatively little mechanical effort. This allows a user to exercise improved control over the delivery process. Further, the mechanisms disclosed herein provide effective push/pull motion while minimizing the number of parts, assembly time, and cost. The push/pull components allow the handle assemblies to maintain a low profile and minimize the overall bulk of the delivery device.
From the foregoing, it will be appreciated that specific embodiments of the technology have been described herein for purposes of illustration, but that various modifications may be made without deviating from the disclosure. Certain aspects of the new technology described in the context of particular embodiments may be combined or eliminated in other embodiments. Additionally, while advantages associated with certain embodiments of the new technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the technology. Accordingly, the disclosure and associated technology can encompass other embodiments not expressly shown or described herein.

Claims

1-14. (canceled)

15. A stent delivery system for deploying a stent, comprising:

a handle for advancing and unsheathing a stent, wherein the handle comprises a dual-threaded internal lead screw configured to engage with a first lead screw and a second lead screw,

wherein the first lead screw is coupled to a tubular enclosure covering the stent and the second lead screw is selectively coupleable to the stent via a dilator,

wherein the first lead screw and second lead screw are of opposing handedness such that rotation of the internal lead screw causes longitudinal translation of the tubular enclosure and stent in opposite directions, and

wherein the first lead screw and second lead screw have respective pitches that enable synchronized, opposing longitudinal translation of the tubular enclosure and stent at a predetermined payout ratio to deploy the stent.

16. The stent delivery system of claim 15 wherein the predetermined payout ratio is equal to a helix angle of the stent.

17. The stent delivery system of claim 15 wherein the predetermined payout ratio is configured to reduce the movement of the stent during unsheathing of the stent.

18. The stent delivery system of claim 17 wherein the predetermined payout ratio of first lead screw to second lead screw is between about 1:1 and 2:1.

19. The stent delivery system of claim 18 wherein the predetermined payout ratio of first lead screw to second lead screw is about 1.5:1.

20. The stent delivery system of claim 15 wherein the handle further comprises a slider mechanism configured to provide incremental stent deployment and reshaping.

21. The stent delivery system of claim 15 wherein the handle further comprises a tip-release slider.

22. The stent delivery system of claim 15 wherein the handle further comprises a cuff mechanism configured to provide incremental stent deployment.

23. The stent delivery system of claim 15 wherein the handle defines one or more lockable positions configured to control incremental stent deployment.

24. The stent delivery system of claim 23 wherein the handle further comprises audio feedback upon placement of the cuff mechanism into the one or more lockable positions.

25. The stent delivery system of claim 15 further comprising a lumen extending axially through the handle and configured to carry contrast or other fluid.

26. The stent delivery system of claim 15 further comprising a seal configured to block fluid from traveling into the handle.

27. The stent delivery system of claim 15 wherein the second lead screw is configured to be in mechanical communication with the stent via a dilator.

28. The stent delivery system of claim 27 wherein, upon rotation of the housing around a longitudinal axis, the first lead screw pulls the tubular enclosure in a proximal direction and the second lead screw pushes a proximal end of the stent in a distal direction to provide simultaneous advancement of the stent and retraction of the tubular enclosure.

29. The stent delivery system of claim 15 wherein the first and second lead screws have semi-circular cross-sections.

30. The stent delivery system of claim 15 wherein the handle comprises at least one keyway spline that engages an axial groove in the first lead screw or second lead screw.

31. The stent delivery system of claim 30 wherein the handle assembly comprises ergonomic contours.

32. A handle assembly for a stent graft delivery system, the handle assembly comprising:

a movable pushing component configured to deliver a distal portion of the stent graft to an arterial target site; and

a moveable pulling component configured to interface with the pushing component and provide a compression force to the distal portion of the stent graft,

wherein the stent graft comprises a helix angle, and

the pulling component is configured to move relative to the pushing component at a ratio corresponding to the helix angle.

33. The handle assembly of claim 32 wherein:

the pushing component comprises a first lead screw coupled to a rotatable shaft and having a first thread pitch; and

the pulling component comprises a second lead screw coupled to the shaft and having a second thread pitch different from the first thread pitch.

34. The handle assembly of claim 32 further comprising a lumen extending axially through the handle assembly and configured to carry contrast or other fluid.

35. A handle assembly for housing, advancing, and unsheathing a stent graft, the housing assembly comprising:

a first travel lead screw configured to be mechanically coupled to a sheath covering the stent graft;

a second travel lead screw configured to be mechanically coupled to the stent graft via a dilator; and

an internal lead screw engaged with the first and second travel lead screws,

wherein the first and second travel lead screws have opposing pitch angles such that rotation of the internal lead screw causes longitudinal translation of the sheath and stent graft in opposing directions, and

wherein the first and second travel lead screws have pitch frequencies that enable opposing longitudinal translation of the sheath and stent graft at a predetermined payout ratio.