Implant delivery system and method of use

Abstract

A method and system for delivering a tubular implant to a target location within a body lumen, the tubular implant having a delivery length when in a radially collapsed delivery configuration and a shortened length that is shorter than the delivery length when in a radially expanded implantation configuration. Respective markers are provided on the delivery catheter and on the tubular implant that provide a visual indication of the landing location of a final proximal portion of the shortened length of the tubular implant prior to implantation of the final proximal portion, thereby allowing a clinician to determine whether the landing location of the final proximal portion is clinically desirable prior to fully implanting the tubular implant.

Description

TECHNICAL FIELD

[0001] The present disclosure generally relates to systems and methods for delivering medical implants. More specifically, the present disclosure relates to a delivery system and a delivery method for delivering a tubular implant to a target site within a patient's vasculature. BACKGROUND ART

[0002] The use of intravascular medical devices and implants has become an effective method for treating a variety of vascular diseases. Generally, a suitable intravascular device is inserted into the patient's vasculature and advanced through the vascular anatomy to a target site within the patient. Using this method, virtually any target site within the patient's vasculature, including coronary, cerebral, and peripheral vascular structures, can be accessed.

[0003] Catheters are often used to place medical implants, such as stents and embolization devices, at desired locations within the body. Typically, a stent is a tubular prosthesis for insertion through a body lumen. However, stents can come in a wide range of sizes and shapes. Stents may be delivered by being mounted on a balloon and placed on a catheter. After positioning the stent at the desired location, the balloon is inflated to expand the stent radially outward. Alternatively, the stent may be mounted on a catheter in a reduced configuration and / or diameter, and the catheter is then withdrawn from the stent, thereby introducing the stent into the lumen of a body blood vessel. For example, self-expanding stents should be delivered in an elastically compressed or folded state, confined within a tubular restraining member such as a catheter. The catheter is advanced through the vascular system until its distal end reaches the implantation site. Furthermore, catheters may be introduced into the patient via a pre-installed guidewire in so-called "over-the-wire" and "rapid-exchange" delivery systems. The folded stent is typically mounted on a pusher member or delivery wire positioned within the lumen of the catheter, so that the stent is introduced, advanced, or pushed through the catheter. Once the stent is positioned adjacent to the desired location, it is unsheathed by withdrawing the catheter from the stent, allowing the stent to expand to a predetermined diameter within the body lumen, thereby engaging with the inner wall of the blood vessel without the need for assistance from a balloon.

[0004] Self-expanding stents may be biased to expand as soon as they are released from the delivery catheter, and / or self-expanding stents may include shape-memory components that allow the stent to expand as soon as it is exposed to a given condition. Some stents may be characterized as composite stents that have some features of both self-expanding and balloon-expanding stents. In either configuration, once delivered to the target site in the body, the expanded stent supports and reinforces the vessel wall while keeping the vessel open and unobstructed.

[0005] In some medical applications, such as bridging the neck of an aneurysm or diverting blood flow from an aneurysm or vessel, precise implantation of a self-expanding stent or tubular implant at the target site is required. Some implant delivery systems include a radio-opaque marker at the distal end of the delivery catheter, allowing physicians to use fluoroscopy systems to estimate the distal landing of the tubular implant as the stent is delivered out of the distal end of the delivery catheter. However, folded self-expanding stents or tubular implants typically have a delivery length greater than their implanted length when confined within the delivery catheter, making it difficult for physicians to estimate the proximal landing of the proximal end of the implanted stent or tubular implant as it expands in the implantation configuration. Therefore, there is a risk of failure and an increased duration of medical treatment, or at least a possibility of failure in delivering a stent or tubular implant within the target location to precisely bridge the neck of an aneurysm or divert blood flow from the vessel, as desired. Thus, there is still a need to provide a delivery system for delivering self-expanding tubular implants that enables more accurate delivery and positioning of the implant at the target location. [Overview of the project]

[0006] In one embodiment of the disclosed invention, a method is provided for delivering a tubular implant to a target location within a body lumen, wherein the tubular implant has a delivery length when in a radially folded delivery configuration and a shortened length which is shorter than the delivery length when in a radially expanded implantation configuration. In other words, a radially folded tubular implant shortens in length when it expands radially, a feature commonly known as shortening. The amount of shortening of the tubular implant depends on the amount of radial expansion of the tubular implant, and the amount of radial expansion depends on the diameter (or other lateral dimension) of the body lumen in which the tubular implant expands. For example, in a smaller diameter body lumen, the tubular implant expands radially less than in a larger diameter body lumen, and the tubular implant shortens less than in a larger diameter body lumen. Often, the diameter of the body lumen varies along the length of the implanted tubular member, in which case the amount of shortening of multiple portions of the tubular implant will vary along the length of the implanted tubular member. For example, if the distal portion of the landing site within the body lumen has a large diameter, and the proximal portion of the landing site within the body lumen has a smaller diameter, the distal portion of the installed tubular member will be shorter than the proximal portion of the tubular member.

[0007] The amount of shortening of a tubular implant, which varies based on the diameter of the body lumen, presents several problems, as well as variations in body lumen diameter. For example, variations in body lumen diameter make it extremely difficult to accurately determine the total shortening length of a tubular implant in its expanded implantation configuration. Determining the total shortening length of a tubular implant in its expanded implantation configuration requires accurately measuring the cross-section of the body lumen along the entire implantation length of the tubular implant, and then determining how much shortening occurs in each portion of the tubular implant along the cross-section of the entire implantation length. Furthermore, even if this measurement can be performed, since the tubular implant is positioned and delivered from the delivery catheter, changes in the position of the tubular implant and changes in the cross-section of the body lumen from the initial measurement of the cross-section used to determine the total implantation length can occur. Therefore, physicians may notice that the position of the final proximal portion of the tubular implant is misaligned from the target proximal landing position of the proximal end of the tubular implant when the implant is fully or substantially fully released into the body lumen from the delivery catheter. For example, a physician might use a fluoroscopy system to visualize implantation and notice that the proximal position of a tubular implant is clinically undesirable. The position may be clinically undesirable for several reasons, including the proximal portion failing to cover the entire aneurysm being treated, the proximal portion adhering to a bend, potentially leading to thrombosis or stroke, or the proximal portion covering another vessel. In this case, the physician may need to reposition the stent. However, repositioning a stent can be extremely difficult once it is fully or nearly fully implanted. For instance, a delivery catheter may be removed from the stent beyond a point of no return, where the tubular component cannot be resheathed within the catheter. This significantly complicates the stent repositioning process, even if it is possible.

[0008] This invention relates to an improved implant delivery system and method of use that enables more accurate determination of the landing position of the terminal proximal portion of a tubular implant. The improved delivery system and method for implanting a shortened tubular implant uses a specially placed marker to indicate when the terminal proximal portion of the tubular implant, at its determined deployed length (i.e., shortened length), remains undeployed from the delivery catheter. In a non-limiting example, a tubular implant may have a complete delivery length of 120 mm in its radially folded delivery configuration. The determined deployed length is determined based on the cross-section of the body lumen at the target proximal landing position of the proximal portion of the tubular implant. As an example, the cross-section may be measured using any appropriate technique such as visualization, estimation based on the type and location of the body lumen, etc. The determined deployed length may then be calculated based on the characteristics of the tubular implant and the cross-section of the body lumen. As an example, the terminal proximal portion may be 9.5 mm in the radially folded delivery configuration and have a determined deployed length of 5 mm at the target proximal landing position. As will be explained in more detail below, a marker is placed on the device to indicate when the delivery catheter has been withdrawn to the point where there is a determined unfolded length (5 mm in this example) remaining unfolded from the delivery catheter. In other words, 9.5 mm of the tubular implant in the radially folded delivery configuration remains within the delivery catheter. In this way, the physician can confirm (by visualization, for example) where the last 5 mm of the implanted tubular implant will attach within the body lumen. Because the improved system and method determines the length of only the shorter proximal portion of the tubular implant, the determination of the position of the terminal proximal portion is far more accurate than with conventional systems and methods. This may reduce or even eliminate the influence of vascular tapering, aneurysm neck length, implant load, and other factors that cause inaccuracies in determining the total length of a shortened tubular implant.

[0009] Accordingly, one embodiment of the present invention relates to a method for delivering a tubular implant to a target location within a body lumen. The tubular implant has a delivery length when in a radially folded delivery configuration and a shortened length which is shorter than the delivery length when in a radially expanded implantation configuration. The implant delivery system comprises a tubular implant positioned within a delivery catheter in a folded delivery configuration. The implant delivery system is inserted into a body lumen and advanced until the distal end of the tubular implant is adjacent to a target distal landing location for the distal end of the tubular implant.

[0010] Next, the delivery catheter is withdrawn to deliver the tubular implant into the body lumen. The delivery catheter is withdrawn until a first marker, positioned on the distal end of the delivery catheter, reaches a second marker positioned on the implant delivery system. For example, the first marker may be positioned on the distal end of the delivery catheter, and the second marker may be positioned on the implant delivery system (e.g., on the tubular implant or delivery wire), so that the first marker moves relative to the second marker as the delivery catheter is withdrawn. In certain embodiments, the first marker may be a single small radiopaque marker. In other embodiments, the first marker may be an elongated radiopaque marker and a radiopaque coil.

[0011] The first and second markers are positioned such that when the first marker reaches the second mark, the terminal proximal portion of the tubular implant remains unexpanded from the delivery catheter. The terminal proximal portion has a determined deployment length, which is the shortened length of the terminal proximal portion in its radially expanded configuration, corresponding to a measured cross-section of the body lumen at the target proximal landing position for the proximal portion of the tubular implant. In other words, the first and second markers indicate when a known shortened length of the tubular implant remains unexpanded within the body lumen, based on the amount of radial expansion of the terminal proximal portion in the cross-section of the target proximal landing position for the terminal proximal portion.

[0012] The shortening length of the terminal proximal portion can be determined by various methods. As one example, a cross-section of the proximal landing position of the body lumen can be measured using any suitable means, such as imaging, gauging, etc. The cross-section may be an average value, a variable profile, or other suitable measurement. The shortening length of the terminal proximal portion in its radially extended configuration can then be calculated or determined based on the measured cross-section.

[0013] In another embodiment of the method, the implant delivery system may also include a re-sheath marker positioned on the implant delivery system. The re-sheath marker is positioned such that when the delivery catheter is withdrawn to the point where a first marker reaches the re-sheath marker, the re-sheath marker indicates the position of the proximal-withdrawn delivery catheter, which is a position where the catheter cannot be advanced distally to re-sheath the tubular implant into the delivery catheter.

[0014] In yet another aspect of the method, a second marker may be placed distal to the resheath marker along the implant delivery system. This ensures that the delivery catheter can be withdrawn so that a known deployment length remains, allowing the tubular implant to be deployed to the terminal proximal portion of the tubular implant, and the tubular member can still be resheathed by advancing the delivery catheter distally on the tubular member. This allows the physician to determine whether the landing position of the terminal proximal portion is clinically desirable, and if not, to resheath and reposition the implant delivery system within the body lumen.

[0015] In yet another embodiment, the method further includes measuring a cross-section of the body lumen at a target proximal landing site, and then placing a second marker longitudinally along the implant delivery system based on the measured cross-section to provide a predetermined deployment length. In this case, the position of the second marker is adjustable to adjust and set the determined deployment length of the final proximal portion of the tubular implant.

[0016] In another embodiment, the method further includes confirming the position of the first marker in the body lumen when the delivery catheter is withdrawn so that the first marker reaches the second marker, and determining whether the proximal landing position of the proximal portion of the tubular implant is clinically desirable based on the confirmed position of the first marker and a predetermined deployment length of the proximal portion of the tubular implant that remains undeployed from the delivery catheter.

[0017] In yet another embodiment, the method further includes determining that the proximal landing position of the proximal portion of the tubular implant is clinically undesirable based on the confirmed position of the first marker and a predetermined deployed length of the proximal portion of the tubular implant that remains undeployed from the delivery catheter. The delivery catheter is then advanced distally to fully reseal the tubular implant within the delivery catheter. In yet another embodiment, the implant delivery system may be repositioned to a new position with the tubular implant fully resealed within the delivery catheter. Once repositioned to a new position, the steps for deploying the tubular implant, determining whether the proximal landing position is clinically desirable, resealing the tubular implant, and / or repositioning the implant delivery system may be repeated as many times as necessary to deploy the tubular implant to a clinically desirable position.

[0018] In another embodiment of the method, the implant delivery system may further include a delivery wire (e.g., a pusher wire) slidably positioned within the delivery catheter. A tubular implant may be mounted on the delivery wire so as to expand into the body lumen from the open end of the delivery catheter when the delivery catheter is withdrawn proximal to the delivery wire. In another embodiment, a second marker may be mounted on the delivery wire.

[0019] In a further embodiment of the method, the tubular implant may include either a stent or a blood diverter.

[0020] In yet another embodiment, the tubular implant may be self-expanding. Alternatively, the tubular implant may be expanded by a balloon system positioned on an implant delivery system.

[0021] According to another embodiment of the disclosed invention, an implant delivery system for implanting a tubular implant into a body lumen is provided. The system includes a delivery catheter comprising an elongated tubular member having a lumen, a proximal end, and an open distal end. A first marker is positioned on the distal end of the delivery catheter. A tubular implant is positioned within the lumen of the tubular member. The tubular implant has a delivery length in a folded delivery configuration within the delivery catheter and a shortened length in a radially expanded implantation configuration when released outside the delivery catheter.

[0022] A delivery wire is slidably positioned within a delivery catheter, and a tubular implant is detachably coupled to the delivery wire for delivery through the open end of the delivery catheter. A second marker is placed on either the delivery wire or the tubular implant. The second marker is positioned such that the terminal proximal portion of the tubular implant, extending from the position of the second marker to the proximal end of the tubular implant, has a determined unfolded length corresponding to a measured cross-section of the body lumen at the target proximal landing position for the terminal proximal portion of the tubular implant in a configuration in which its radially expanded and shortened portions are arranged. Similar to the method described above, the first and second markers indicate when a known shortened length of the tubular implant remains unfolded within the body lumen, based on the amount of radial expansion of the terminal proximal portion in the cross-section of the target proximal landing position for the terminal proximal portion.

[0023] In another embodiment, the implant delivery system may further include a resheath marker positioned on the implant delivery system, so that when the delivery sheath is withdrawn from the tubular implant, the first marker moves with the delivery sheath relative to the resheath marker. The resheath marker is positioned such that when the delivery catheter is withdrawn to the point where the first marker reaches the resheath marker, the resheath marker indicates the position of the proximal-withdrawn delivery catheter, which is a position where the catheter cannot be advanced distally to resheat the tubular implant into the delivery catheter.

[0024] In yet another embodiment, a second marker may be positioned distal to the resheath marker along the implant delivery system. This ensures that the delivery catheter can be withdrawn so that a known deployment length remains, allowing the tubular implant to be deployed to the terminal proximal portion of the tubular implant, and the tubular member can still be resheathed to advance the delivery catheter distally on the tubular member. This allows the physician to determine whether the landing position of the terminal proximal portion is clinically desirable, and if not, to resheath and reposition the implant delivery system within the body lumen.

[0025] In another aspect, the second marker may be disposed along the longitudinal direction of the implant delivery system based on the measured cross-section of the body lumen at the target proximal landing position, so as to provide a determined deployment length of the proximal portion of the tubular implant.

[0026] In yet another aspect, the measured cross-section of the body lumen at the target proximal landing position may be the average diameter of the body lumen along a portion of the body lumen at the target proximal landing position. The cross-section may be an average value, a variable profile, or other suitable measurement value of the body lumen. The shortened length of the final proximal portion in the radially expanded configuration is then calculated or determined based on the measured cross-section. In another aspect, the measured cross-section of the body lumen at the target proximal landing position may be based on the measurement of the cross-section of the body lumen at the target proximal landing position. For example, the cross-section of the proximal landing position of the body lumen may be measured using any suitable means such as imaging, gauging and the like. In an alternative aspect, the measured cross-section of the body lumen at the target proximal landing position may be based on an approximation using a standard cross-section of the body lumen.

[0027] In yet another aspect, the second marker may be adjustably positionable on the delivery wire or the tubular implant such that it can be adjusted to set the determined deployment length of the final proximal portion.

[0028] In yet another aspect, the second marker may be mounted on the delivery wire. In an alternative aspect, the second marker may be disposed on the tubular implant.

[0029] In yet another aspect, the tubular implant may be a stent or a blood flow diverter. In yet another aspect of the system, the tubular implant may be self-expanding. Alternatively, the tubular implant may be expanded by a balloon system disposed on the implant delivery system.

[0030] Another embodiment of the present invention is directed to systems and methods in which a set of implant delivery systems for implanting a tubular implant is made available, wherein each delivery system is configured for a different cross-section of a proximal landing position in a body lumen. A clinician may measure the cross-section of the proximal landing position and then select an implant delivery system configured for that cross-section. Accordingly, a selection of implant delivery systems is made available that includes a plurality of delivery systems, each configured for a different cross-section (i.e., cross-sectional diameter) of the proximal landing position of the body lumen. The axial position of the proximal portion marker is set on each respective delivery system to provide a predetermined deployment length of the final proximal portion for a given cross-section of the proximal landing position of the body lumen. For example, the set of implant delivery systems may be configured to provide a consistent predetermined deployment length (e.g., 5 mm) for a variety of different cross-sections (e.g., 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, 5.0 mm, etc.).

[0031] A method of selecting and using an implant delivery system from a set of a plurality of implant delivery systems is as follows. First, the cross-section of the proximal landing position of the body lumen is measured. The clinician then selects the appropriate implant delivery system from the set that best corresponds to the measured cross-section. The selected implant delivery system is then used according to the same method as described above.

[0032] A further embodiment of the present invention relates to a medical assembly for implanting a tubular implant, wherein the tubular implant is configured to be used for a range of cross-sections of a proximal landing site in a body lumen. This medical assembly is very similar to the medical assembly described above, except that it includes a delivery system having a tubular implant having two proximal markers, a first proximal marker and a second proximal marker, instead of a single proximal marker. The two proximal markers are axially positioned to provide a predetermined unfolded length for a range of cross-sections of a range of proximal landing sites in a body lumen. The first and second proximal markers 55b may have different shapes or different radiopaque markings to visually distinguish the markers from each other. The first and second proximal markers are positioned at different axial positions on the tubular implant, such that the first proximal marker is positioned axially distal to the second proximal marker. For example, a first proximal portion marker can provide a predetermined unfolded length (e.g., 5.0 mm) at a first cross section (e.g., 4.0 mm) of the proximal landing position, and a second proximal portion marker can provide a predetermined unfolded length (e.g., 5.0 mm) at a second cross section (e.g., 3.5 mm) below the first cross section. Thus, the delivery system provides a nominal predetermined unfolded length (e.g., 5.0 mm) for the range from the first cross section to the second cross section (e.g., from 3.5 mm to 4.0 mm).

[0033] In yet another embodiment, the selection of implant delivery systems for various ranges of cross-sections may be provided in a similar manner to the selection of implant delivery systems described above. Each of the delivery systems in a set of multiple delivery systems is configured for various ranges of cross-sections (i.e., various ranges of cross-sectional diameters) of the proximal landing position of the body lumen. In this way, the axial positions of the two proximal portion markers are set on each respective delivery system to provide a predetermined unfolded length for a given range of cross-sections of the proximal landing position of the body lumen. For example, a set of implant delivery systems may be configured to provide a predetermined unfolded length (e.g., 5 mm) for various different ranges of cross-sectional diameters such as 3.0–3.5 mm, 3.5–4.0 mm, 4.0–4.5 mm, 4.5–5.0 mm, 5.0–5.5 mm, etc.

[0034] The method for selecting and using implant delivery system 102 from a set of multiple ranged implant delivery systems is as follows: First, a cross-section of the proximal landing site of the body lumen is measured. Next, the clinician selects from the set of ranged implant delivery systems that have a distance range that includes or encompasses the measured cross-section. Then, the selected ranged implant delivery system is used in the same manner as described above. [Brief explanation of the drawing]

[0035] [Figure 1] Figure 1 is a side view of a medical assembly including an implant delivery system for delivering a tubular implant, according to one embodiment of the disclosed invention. [Figure 2] Figures 2A and 2B are partial cross-sectional views of the implant delivery system of Figure 1, showing how a tubular implant is deployed from a delivery catheter into a target site in the body lumen using the implant delivery system of Figure 1. [Figure 3] Figures 3A–3E are cross-sectional views illustrating the method of delivering a tubular implant into a patient's target site using the implant delivery system shown in Figure 1. [Figure 4] Figure 4 is a side view of a medical assembly including a remote implant delivery system for delivering tubular implants, according to another embodiment of the disclosed invention. [Figure 5] Figures 5A and 5B are partial cross-sectional views of the remote implant delivery system of Figure 4, showing how a tubular implant is deployed from a delivery catheter into a target site in the body lumen using the implant delivery system of Figure 1. [Figure 6] Figure 6 is a side view of a medical assembly including an implant delivery system for delivering a tubular implant, according to yet another embodiment of the disclosed invention. [Figure 7] Figures 7A and 7B are partial cross-sectional views of the implant delivery system of Figure 6, showing how a tubular implant is deployed from a delivery catheter into a target site in the body lumen using the implant delivery system of Figure 6. [Modes for carrying out the invention]

[0036] The following definitions apply to the terms defined below, unless otherwise specified in the claims or elsewhere in this specification.

[0037] In this specification, all numerical values ​​are considered to be modified by the term “approximately,” whether expressly indicated or not. The term “approximately” generally means a range of numbers that a person skilled in the art would consider equivalent to (i.e., having the same function or result as) the stated value. Often, the term “approximately” may include numbers rounded to the nearest significant figure. Numerical ranges described by endpoints include all numbers within that range (for example, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). In this specification and the appended claims, the singular forms “a,” “an,” and “the” include multiple references unless the content explicitly indicates otherwise. In this specification and the appended claims, the term “or” is generally used in its sense to include “and / or,” unless the content explicitly indicates otherwise.

[0038] Various embodiments of the disclosed invention will be described below with reference to the figures. The figures are not necessarily drawn to a fixed scale, and the relative scale of selected elements may be exaggerated for clarity, and elements of similar structure or function are represented by similar reference numerals throughout the figures. It should be understood that the figures are intended solely to facilitate the description of the embodiments and are not intended as a comprehensive description of the invention or as a limitation of the scope of the invention as defined solely by the appended claims and their equivalents. Furthermore, the illustrated embodiments of the disclosed invention do not necessarily have all the aspects or advantages shown. Aspects or advantages described in relation to a particular embodiment of the disclosed invention are not necessarily limited to that embodiment and may be practiced in any other embodiment, even if not shown as such.

[0039] Referring to Figure 1, a side view of a medical assembly 10 for delivering an expandable tubular implant 20 into a patient's target site is shown according to one embodiment of the disclosed invention. The medical assembly 10 includes a delivery system 12 having a tubular implant 20, such as a stent or diverter, which is detachably coupled to the implant delivery system 12. The delivery system 12 and the tubular implant 20 may be made of suitable polymer materials, metals, and / or alloys, such as polyethylene, stainless steel, or other suitable biocompatible materials or combinations thereof.

[0040] The delivery system 12 is sized to reach remote locations in vascular structures and is configured to deliver the tubular implant 20 to target locations within the patient's body, such as intravascular occlusions, intravascular vessels adjacent to aneurysm necks, branched vessels, etc. The delivery system 12 includes a delivery configuration in which the tubular implant 20 is in a radially constrained and folded configuration and has a complete delivery length L1 (see Figures 1, 3A-B). The delivery system 12 further includes an unfolded configuration in which the tubular implant 20 expands into an unfolded configuration when unfolded outside the delivery system 12 and has a complete implantation length L2 (Figures 2, 3A) which is shorter than the delivery length L1, as will be described in more detail below.

[0041] The tubular implant 20 includes a tubular elastic member having a proximal end 22 and a distal end 24, defining a lumen 26 extending between them. The tubular implant 20 is biased to expand from a constrained delivery configuration by the delivery catheter 40 to a radially expanded implantation configuration when released from the delivery catheter 40. When expanding to the radially expanded implantation configuration, the tubular member 20 shortens. In other words, when the tubular implant 20 is constrained within the catheter 40 in a radially constrained and folded configuration, the delivery length L1 (Figures 1, 3A-B) of the tubular implant 20 is longer than the implantation length L2 (Figures 2, 3A). When released from the delivery system 12, the tubular implant 20 is biased to expand radially outward.

[0042] The tubular implant 20 may be composed of various materials such as stainless steel, Elgiloy, nickel, titanium, Nitinol, shape memory polymer, or a combination thereof. The tubular implant 20 may also be formed in various ways. For example, the tubular implant 20 may be formed by etching or cutting a pattern from a tube or sheet of stent material. A sheet of stent material may be cut or etched according to a desired stent pattern, and then the sheet may be wound or otherwise formed into a desired substantially tubular shape, branched shape, or other shape. In the case of the tubular implant 20, one or more wires or ribbons of stent material may be woven, braided or otherwise formed into a desired shape and pattern. The tubular implant 20 may include further components that are welded or bonded or otherwise engaged with one another. The tubular implant 20 may include, for example, a cover of a non-porous, impermeable, biocompatible material when the tubular implant 20 is used as a blood diverter.

[0043] The delivery system 12 includes a delivery catheter 40 having a proximal end portion 42, a distal end portion 44 including an open distal end portion 46, and a delivery lumen 48 extending between the proximal end portion 42 and the distal end portion 44. The delivery system 12 may also include a pusher member 30 slidably disposed within the delivery lumen 48 of the delivery catheter 40. The pusher member 30 has a proximal end portion 32, a distal end portion 34, and a guidewire lumen 36 extending between them. The tubular implant 20 is positioned within the delivery catheter 40 and distal to the pusher member 30 so that the pusher member 30 can prevent the tubular implant 20 from moving proximally when the delivery catheter 40 is moved proximally to deploy the tubular implant 20 outside the distal end 46 of the opening of the delivery catheter 40, that is, to unsheathe the tubular implant 20 while the distal end 24 of the implant 20 remains in approximately the same position within the blood vessel 90) (Figures 3B-D), as will be described in more detail below.

[0044] Alternatively, the distal end portion 34 of the pusher member 30 may include an actuator 85 (not shown) which includes a mechanical separation interface such as an inflatable balloon, a releasable interlocking geometry, a mechanical clamp, or a release mechanism actuated by electrolysis, or a combination thereof, for deploying the tubular implant 20 out of the distal end tip 46 of the delivery catheter 40. If the actuator 85 includes a balloon, the balloon is in fluid communication with the guidewire lumen 36 for inflation and deflation. An inflation source and / or vacuum source (not shown) is fluidically coupled to the guidewire lumen 36 to deliver fluid and / or gas to the balloon or the distal end tip 46 of the delivery catheter 40, and to withdraw fluid and / or gas from the balloon or the distal end tip 46 of the delivery catheter 40.

[0045] The tubular implant delivery system 12 includes a side arm adapter 14 that is in fluid communication with the delivery lumen 48 of the delivery catheter 40, and a side arm adapter 16 that is in fluid communication with the guidewire lumen 36 of the pusher member 30. The side arm adapters 14 and 16 are configured to be coupled to a syringe, a fluid source and / or a vacuum source (not shown). The delivery catheter 40 may have a total length of about 50 to 300 cm, typically about 60 to 200 cm. The delivery catheter 40 is configured to access a blood vessel or body lumen 90 for the desired treatment at a target site. For example, the target site may be located in a small-diameter blood vessel having an inner diameter of 2 to 5 mm and accessible via a winding vascular route that may involve sharp turns and branching of multiple vessels. In such cases, the delivery system 12, in particular the delivery catheter 40, has a appropriately small-diameter and flexible configuration.

[0046] Furthermore, the delivery system 12 may also include a guidewire 80 having a proximal portion 82 and a distal portion 84. Generally, the proximal portion 82 may be formed from a stiffer material than the distal portion 84 of the guidewire 80 so as to have sufficient pushability to advance the guidewire 80 through the patient's vascular system, while the distal portion 84 may be formed from a more flexible material so as to remain flexible and more easily traverse its path to access remote locations in the winding regions of the vascular structure. In some cases, the proximal portion 82 of the guidewire 80 may include a reinforcing layer, such as a braided or coiled layer, to enhance the pushability of the guidewire 80. When using the delivery system 12, the delivery catheter 40, pusher member 30, and implant 20 are introduced into the patient via the pre-introduced guidewire 80. The guidewire 80 can extend through the lumen 36 and penetrate the entire length of the delivery catheter 40 and pusher member 30 (see Figure 1). Alternatively, in a so-called "rapid exchange" delivery system (not shown), the guidewire 80 may extend only through the distal portions of the delivery catheter 40 and the pusher member 30.

[0047] Returning to the delivery catheter 40, the distal portion 44 of the delivery catheter 40 is equipped with a radiopaque first marker 52 (also called the “catheter distal end marker 52”) on the distal end of the delivery catheter 40 (see Figures 1-3E). The catheter distal end marker 52 is formed of one or more radiopaque biocompatible materials, such as platinum, gold, tungsten, or an alloy thereof, or other metals. The catheter distal end marker 52 on the delivery catheter 40 also overlaps with or otherwise indicates the position of the distal end 24 of the tubular implant 20 when the tubular implant 20 is loaded into the delivery catheter 40 in the ready-to-deploy position in the delivery system 12 (Figures 1, 3A-B).

[0048] In this specification, the term “ready to deploy position” means the position of the implant 20 in the distal end portion 44 of the catheter, which is close to the tip 46 of the opening (as shown in Figure 1), immediately before the implant 20 is deployed into the body lumen 90 by withdrawing the delivery catheter 40 relative to the implant 20 while the implant 20 is prevented from moving proximal to it by the pusher member 30. Thus, the distal end 24 of the implant 20 when it is in the “ready to deploy position” within the delivery catheter 40 is in the same position as, or substantially the same position as, the distal end 24 of the implant 20 that would be in when it is deployed outside the delivery catheter 40. Furthermore, the distal end 24 of the implant 20 may include a radiopaque marker (not shown) configured to assist in the overlap and positional alignment of the distal end 24 of the implant 24 with the distal marker 52 of the delivery catheter 40. The implant 20 may be positioned in a “ready-to-deploy” position within the delivery catheter 40 before the delivery catheter 40, pusher member 30, and implant 20 are introduced into the patient as a single unit via the guidewire 80, as described in detail below. Alternatively, the delivery catheter 40 may be introduced into the patient before the implant 20 and pusher member 30 are introduced into the proximal end portion 42 of the delivery catheter 40 and pushed toward the distal end portion 44. In these latter embodiments, a radiopaque marker on the distal end 24 of the implant 20 facilitates in vivo alignment of the distal end 24 of the implant 20 with the distal end 46 of the catheter 40 (and the catheter distal end marker 52).

[0049] The distal end marker 52 of the catheter can be used to confirm the distal landing position of the distal end 24 of the tubular implant 20 when the implant is placed in the body lumen 90 at any given time by withdrawing the delivery catheter 40 from the implant 20 (Figures 1, 3B-3C). Thus, the clinician can select a desired (or "target") distal landing position by observing the body lumen 90 on an imaging device (e.g., fluoroscopy) and manipulating the delivery catheter 40 until the distal marker 52 is positioned at the target distal landing position.

[0050] The implant delivery system 12 also has one or more implant markers 54, including a second marker 54a, a third marker 54b, and a fourth marker 54c (collectively referred to as “implant markers 54”), which are positioned on the implant delivery system 12 (Figures 1-3). The implant markers 54 may be positioned on the tubular implant 20, on the delivery wire 80, or on other suitable structures of the implant delivery system 12. The implant markers 54 are configured such that a catheter distal end marker 52 moves relative to the implant marker 54 when the delivery catheter 40 is moved proximal to the tubular implant 20 to deploy the tubular implant 20 from the distal end tip 46 of the opening of the delivery catheter 40 into the body lumen 90. The following description will describe the implant markers 54 as positioned on the tubular implant 20, with the understanding that the implant markers 54 may be positioned on any suitable structure of the implant delivery system 12. The implant marker 54 is also formed from one or more radiopaque, biocompatible materials, such as platinum, gold, tungsten, or alloys thereof, or other materials.

[0051] A second marker 54a (also called the “terminal proximal portion marker 54a”) is positioned on the tubular implant 20 to indicate the distal end of the terminal proximal portion 60 of the tubular implant 20. The terminal proximal portion 60 of the tubular implant 20 is the shorter length of the tubular implant 20 which can be used by the physician to determine the proximal landing position 62 of the proximal portion 22 of the tubular implant 20 when the delivery catheter 40 is withdrawn from the tubular implant 20 to the position of the terminal proximal portion marker 54a. For example, the delivery length LPP1 of the terminal proximal portion 60 in a folded delivery configuration is typically 5–10 mm (or 5–20 mm), and the implantation shortening length LPP2 of the terminal proximal portion 60 in a radially expanded implantation configuration is typically about 2–5 mm (or 2–10 mm) (see Figures 1, 2A, 2B, 3A, 3B). As described herein, the amount of shortening of the final proximal portion 60 depends on the cross-section of the body lumen 90 at the proximal landing position 62 of the final proximal portion 60. For example, if the diameter of the tubular implant 20 in the folded delivery configuration is 2 mm and the cross-section of the body lumen 90 at the proximal landing position 62 is 5 mm, the tubular implant 20 may be shortened by 50%. As described herein, the amount of shortening of the final proximal portion 60, and therefore the shortened unfolded length of the final proximal portion 60, can be determined by measuring the cross-section of the body lumen 90 at the proximal landing position 62. In such a case, for a final proximal portion 60 having a delivery configuration length LPP1 of 10 mm, the shortened unfolded length LPP2 in the body lumen 90 will be 5 mm.

[0052] In an alternative embodiment, the terminal proximal portion marker 54a may be an axially elongated marker 54a having a distal end at the distal end of the terminal proximal portion and extending axially to a proximal end proximal to the distal end. For example, the terminal proximal portion marker may be a solid line marker placed on the tubular implant 20, or the terminal proximal portion marker may be a coating of marker material on the delivery wire 80. The axially elongated marker 54a may have a known length, such as 5 mm or 10 mm, to provide the physician with a visual gauge.

[0053] Next, a method for determining the shortened delivery length LPP2 of the final proximal portion 60 at the proximal landing position 62 is described. In the first method, the actual cross-section of the body lumen 90 at the predicted proximal landing position 62 within the body lumen 90 is measured. For example, the cross-section may be measured using any suitable means, such as visualization by an imaging system including an external imaging system or an imaging catheter system inserted into the body lumen 90 at the predicted proximal landing position 62, or by a gauge. The measured cross-section is then used to determine the shortened delivery length LLP2 of the final proximal portion 60 of the tubular implant 20. The shortened delivery length LLP2 may be determined using the dimensions and physical properties of the tubular implant 20, a shortening chart generated from empirical data on the shortening of the tubular implant 20 as a function of the cross-section in which the tubular implant 20 is unfolded, etc. In the other method, the cross-section of the body lumen 90 at the predicted proximal landing position 62 within the body lumen 90 may be an estimate based on the "typical" dimensions (e.g., "standard" cross-sectional diameter) of a particular body lumen. For example, a "standard" cross-section of a section of the cerebral artery, a common location for stent placement, is approximately 4 mm. Therefore, considering this 4 mm standard cerebral artery cross-section, as well as the dimensions and characteristics of the tubular implant 20, the deployed length LPP2 of the terminal proximal portion 60 at the proximal landing position 62 can be determined in the same way as, or similarly to, using the actual measured cross-section.

[0054] In an alternative embodiment, the terminal proximal portion marker 54a may be adjustablely positioned on the tubular implant 20. In this embodiment, the axial position of the terminal proximal portion marker 54a may be set to the determined unfolded length of the terminal proximal portion 60. For example, it may be desirable for the physician to be able to visualize when there is a determined unfolded length LPP2 of 5 mm of the terminal proximal portion 60 at the proximal landing position 62. The cross section of the body lumen 90 at the proximal landing position 62 is first measured, and then the length LPP1 of the terminal proximal portion 60 in the folded delivery configuration, which will be shortened to a determined unfolded length of 5 mm, is determined based on the cross section of the proximal landing position 62 (as well as the diameter and physical properties of the tubular member 20). The terminal proximal portion marker 54a is then positioned distal to the proximal end 22 of the tubular member by the determined length LPP1.

[0055] A third marker 54b (also called the “resheat marker 54b”) is positioned on the tubular implant 20 to indicate the position of the delivery catheter 40 that is proximal to a position where the delivery catheter cannot be advanced in the opposite direction to resheat the tubular implant 20. For example, if the physician determines that the landing position of the tubular implant 20 in the body lumen is clinically desirable or if any other complications exist during the implantation procedure, the physician can resheat the tubular implant 20 into the delivery catheter 40 by advancing the delivery catheter 40 distally over the unfolded portion of the tubular member 20 so that the tubular implant returns to the folded delivery configuration within the delivery catheter 40. The physician can then reposition the implant delivery system 12 in the body lumen 90 or remove the implant delivery system 12 from the patient. As shown in the illustrated embodiment, the resheat marker 54b is positioned proximal to the final proximal portion marker 54a. This allows the delivery catheter 40 to be withdrawn proximal to at least the terminal proximal marker 54a, so that the physician can determine the proximal landing position 62 of the terminal proximal portion 60, and if the proximal landing position 62 is clinically undesirable, the implant delivery system 12 can be resheathed and repositioned. Alternatively, the resheath marker 54b may be positioned distal to the terminal proximal marker 54a, in which case, when the delivery catheter 40 is withdrawn to the terminal proximal marker 54a, the delivery catheter 40 will have been withdrawn beyond the resheath marker 54b, and the tubular member 20 cannot be resheathed.

[0056] A fourth marker 54c (also called the "proximal implant marker 54c") is positioned on the proximal end of the tubular member 20. The proximal implant marker 54c allows the physician to visualize the position of the proximal end of the tubular member 20 during the implantation procedure.

[0057] Figure 1 shows the implant delivery system 12 in a ready-to-deploy configuration, where the tubular implant 20 is in a folded delivery configuration and fully inserted into the delivery lumen 48 of the delivery catheter 30. The distal end 24 of the tubular implant 20 is axially aligned with the catheter distal end marker 52 (if the tubular implant 20 has an implant distal end marker, the implant distal end marker is axially aligned with the catheter distal end marker 52).

[0058] Next, with reference to Figures 2A and 2B, a method for implanting a tubular implant 20 into a body lumen 90 using the medical system 10 and the implant delivery system 12 will be described. Figure 2A shows the implant delivery system 12 of Figure 1 with the delivery catheter 40 partially withdrawn axially, thereby unfolding the distal portion 24 of the tubular member 20. Thus, the distal portion 24 of the tubular member 20 is in a radially expanded implantation configuration. After gaining access to the patient's vascular structure area, the delivery catheter 40, the tubular implant inserted therein, and the pusher member 30 are introduced into the patient via a guidewire 80 that had been previously inserted into the body lumen 90. The delivery catheter 40 is advanced until the distal end marker 52 of the catheter is positioned adjacent to the target distal landing position 64 for the tubular implant 20, for example, beyond the neck 94 of the aneurysm 92. Next, the clinician withdraws the delivery catheter 40 while the pusher member 30 holds the tubular member 20 in place so that the tubular member 20 is deployed outside the open distal end 46 of the delivery catheter 40. As shown in Figures 1 and 2B, the actual full implantation length L2 of the tubular implant 20 in the expanded implantation configuration is shorter than the full delivery length L1 in the radially constrained and folded configuration. In Figure 2A, the delivery catheter 40 has been withdrawn to the point where the distal end marker 52 reaches the terminal proximal portion marker 54a, and as a result, only the terminal proximal portion 60 of the tubular member 20 remains undeployed from the delivery catheter 40. At this position of the delivery catheter 40, it is known that the terminal proximal portion 60 extends proximal from the terminal proximal portion marker 54a (and also from the distal end marker 52) by a determined shortened deployment length LPP2. Therefore, clinicians can visualize the actual proximal landing position 62 of the terminal proximal portion 60 of the tubular implant 20. Clinicians can determine whether the actual proximal landing position 62 of the tubular implant 20 is clinically desirable.As shown in Figure 2A, the delivery catheter 40 has not yet been withdrawn beyond the point where the tubular implant 20 can be resheathed, as indicated by the distal end catheter marker 52 remaining distal to the resheath marker 54b. If the clinician determines that the actual proximal landing position 62 of the tubular implant 20 is clinically undesirable, the clinician can resheath the tubular implant 20 by advancing the delivery catheter 40 distally while holding the tubular implant 20 in place relative to the delivery catheter 40 using the pusher member 30. Once the tubular implant 20 is fully resheathed (i.e., the delivery catheter 40 is advanced until the distal end marker 52 is adjacent to the distal end 24 of the tubular implant 20, and the tubular implant 20 is again radially constrained and folded), the clinician can reposition the implant delivery system 12. If the actual proximal landing position 62 of the tubular implant 20 is determined to be clinically desirable, the clinician can continue to withdraw the delivery catheter 40 to deploy the final proximal portion 60 of the tubular implant 20.

[0059] Figure 2B shows the implant delivery system 12, in which the delivery catheter 40 is fully withdrawn axially, deploying the entire tubular member 20, and as a result the terminal proximal portion 60 is also deployed within the body lumen 90 and in a radially expanded implantation configuration, and the terminal proximal portion 60 is now shortened to the determined deployed length LPP2. The tubular implant 20 is also separated from the pusher member 30 by using an actuator 85 for separating the tubular member 20.

[0060] Looking at Figures 3A–3E, a method of using the medical system 10 and implant delivery system 12 to deliver an implant to a target site in a body lumen 90 using the delivery system 12. As described herein, the shortened length LPP2 of the terminal proximal portion 60 of the tubular member 20 is determined or set. This allows the clinician to accurately determine the proximal landing position 62 of the terminal proximal portion of the implanted tubular member 20, as described below.

[0061] First, the guidewire 80 is advanced through the patient's vascular structure region so that its distal end 84 is positioned distal to the target distal landing position 64 in the body lumen, and positioned along the desired landing position for the tubular implant 20 in the body lumen 90. As shown in Figure 3A, the delivery catheter 40, having the tubular implant 20 loaded in the delivery lumen 48 in its radially constrained and folded configuration, is inserted into the body lumen 90. The tubular implant 20 is fully inserted into the delivery catheter 40 so that its distal end 24 is adjacent to the catheter distal end marker 52. The delivery catheter 50 and the tubular implant 20 are advanced into the body lumen 90 along the guidewire 80, with the guidewire 80 positioned in the guidewire lumen 36 of the pusher member 30.

[0062] As shown in Figure 3B, the implant delivery system 12 is advanced until the distal end marker 52 of the catheter indicates that the distal end 24 of the tubular implant 20 is positioned adjacent to the target distal landing position 64 for the distal end 24 of the tubular implant 20 when implanted in the body lumen 90. The clinician can visualize the position of the distal end marker 52 using an appropriate imaging system.

[0063] As shown in Figure 3C, the delivery catheter 40 is withdrawn proximal to the pusher member 30, thereby delivering the tubular implant 20 into the body lumen 90 from the open distal end 46 of the delivery catheter 40, such that the distal end 24 of the implant 20 remains substantially in the same position as the target distal landing position 64. Once delivered outside the delivery catheter 40, the tubular implant 20 expands radially outward and then shortens.

[0064] As shown in Figure 3D, the delivery catheter 40 is continued to be withdrawn from the pusher portion 30 until the distal end marker 52 reaches the terminal proximal portion marker 54a, so that only the terminal proximal portion 60 of the tubular member 20 remains unextended from the delivery catheter 40. At this position of the delivery catheter 40, it is known that when the terminal proximal portion 60 is extended out of the delivery catheter 40, it will extend proximal from the terminal proximal portion marker 54a (and also from the distal end marker 52) by a determined shortened extension length LPP2. Thus, the clinician can visualize the actual proximal landing position 62 of the terminal proximal portion 60 of the tubular implant 20. The clinician can determine whether the actual proximal landing position 62 of the tubular implant 20 is clinically desirable.

[0065] As shown in Figure 3D, the delivery catheter 40 has not yet been withdrawn beyond the point where the tubular implant 20 can be resheathed, as indicated by the fact that the distal end marker 52 of the catheter is still distal to the resheath marker 54b.

[0066] The delivery catheter 40, located in the position shown in Figure 3D, allows the clinician to determine whether the actual proximal landing position 62 of the tubular implant 20 within the body lumen 90 is clinically desirable. Since the shortened extension length LPP2 of the terminal proximal portion 60 is known, the clinician can visualize the actual proximal landing position 62 of the tubular implant 20 within the body lumen 90.

[0067] Once the clinician has measured the actual proximal landing position 62 of the tubular implant 20 within the body lumen 90, the clinician can then resheath the tubular implant 20 by advancing the delivery catheter 40 distally while using the pusher member 30 to hold the tubular implant 20 in place relative to the delivery catheter 40. Once the tubular implant 20 is fully resheathed (i.e., the delivery catheter 40 has been advanced until the distal end marker 52 of the tubular implant 20 is adjacent to the distal end 24 of the tubular implant 20) and the tubular implant 20 is again radially constrained and folded, the clinician can reposition the implant delivery system 12 or even remove the implant delivery system 12 and restart the procedure.

[0068] As shown in Figure 3E, if the actual proximal landing position 62 of the tubular implant 20 is determined to be clinically desirable, the clinician continues to withdraw the delivery catheter 40 from the pusher member 30 to deploy the terminal proximal portion 60 of the tubular implant 20. The delivery catheter 40 is completely withdrawn from the tubular implant 20 so that the terminal proximal portion 60 is also deployed into the body lumen 90. The terminal proximal portion 60 expands into a radially expanded implantation configuration to shorten to the determined deployment length LPP2. The tubular implant 20 is then separated from the pusher member 30, for example by using the actuator 85 to separate the tubular member 20, also as shown in Figure 3E. The tubular member 20 is now fully implanted in the body lumen 90. The remainder of the implant delivery system 12 may be completely withdrawn from the body lumen 90, leaving the tubular member implanted in the body lumen 90.

[0069] In yet another embodiment, a selection of implant delivery systems 12 is provided, each of which is configured for different cross-sections (i.e., cross-sectional diameters) of the proximal landing position 62 of the body lumen 90. The axial position of the proximal portion marker 54a is set on each respective delivery system 12 to provide a predetermined unfolded length LPP2 of the final proximal portion 60 for a given cross-section of the proximal landing position 62 of the body lumen 90. For example, a set of implant delivery systems 12 may be configured to provide a predetermined unfolded length LPP2 of 5 mm for various different cross-sections such as cross-sectional diameters of 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, 5.0 mm, etc. In other words, the set includes a first implant delivery system 12 for a 3.0 mm cross-sectional diameter having a proximal portion marker 54a positioned axially so that the unfolded length LPP2 in a 3.0 mm lumen is 5 mm; a second implant delivery system 12 for a 3.5 mm cross-sectional diameter having a proximal portion marker 54a positioned axially so that the unfolded length LPP2 in a 3.5 mm lumen is 5 mm; a third implant delivery system 12 for a 4.0 mm cross-sectional diameter having a proximal portion marker 54a positioned axially so that the unfolded length LPP2 in a 4.0 mm lumen is 5 mm, and so on.

[0070] The method for selecting and using an implant delivery system 12 from a set of multiple implant delivery systems 12 is as follows: First, the cross-section of the proximal landing position 62 of the body lumen 90 is measured. Then, the clinician selects one implant delivery system 12 from the set that best corresponds to the measured cross-section. For example, if the measured cross-section is 4.0 mm, a 4.0 mm implant delivery system 12 is selected. Then, the selected implant delivery system 12 is used in the same manner as described above in relation to Figures 3A-3E.

[0071] Turning to Figures 4 and 5A–5B, another medical assembly 100 for delivering an expandable tubular implant 20 into a patient's target site is shown according to another embodiment of the disclosed invention. Medical assembly 100 is very similar to medical assembly 10 described above, except that it includes a delivery system 102 (also called the “long-distance implant delivery system 102”) having a tubular implant 20 having two proximal markers 55a and 55b instead of a single proximal marker 54a. The two proximal markers 55a and 55b are axially positioned to provide a predetermined unfolded length LPP2 for a range of cross-sections of the proximal landing position 62 of the body lumen 90. The first proximal marker 55a and the second proximal marker 55b may have different shapes or different radiopaque markings to visually distinguish the markers from each other. The first proximal marker 55a and the second proximal marker 55b are positioned at different axial locations on the tubular implant 20. In this example, the first proximal marker 55a is positioned axially distal to the second proximal marker 55b. The first proximal marker 55 defines the final proximal portion 60a, and the second proximal marker 55b defines the final proximal portion 60b. Since the first proximal marker 55a is distal to the second proximal marker 55b, the first proximal marker indicates a given unfolded length for a larger diameter section than the second proximal marker 55b. This is because the final proximal portion for a larger diameter section of the proximal landing position 62 will be proportionally shorter than the final proximal portion for a smaller diameter section. For example, the first proximal portion marker 55a can provide a predetermined unfolded length (e.g., 5.0 mm) at a first cross section (e.g., 4.0 mm) of the proximal landing position 62, and the second proximal portion marker 55b can provide a predetermined unfolded length (e.g., 5.0 mm) at a second cross section (e.g., 3.5 mm) less than the first cross section. Thus, in this example, the medical assembly 100 having this tubular implant 20 is configured to provide a nominal predetermined unfolded length of approximately 5.0 mm for a cross section range from 3.5 mm to 4.0 mm.

[0072] In yet another embodiment, the selection of the long-distance implant delivery system 102 may be provided in the same way as the selection of the implant delivery system 12 described above. Each of the delivery systems 102 in the set of multiple delivery systems is configured for a range of cross-sections (i.e., different cross-sectional diameters) of the proximal landing position 62 of the body lumen 90. Thus, the axial positions of the two proximal portion markers 55a and 55b are set on each respective delivery system 102 to provide a predetermined unfolded length LPP2 for a given range of cross-sections of the proximal landing position 62 of the body lumen 90. For example, a set of implant delivery systems 12 may be configured to provide a predetermined unfolded length LPP2 of 5 mm for a range of different cross-sectional diameters such as 3.0-3.5 mm, 3.5-4.0 mm, 4.0-4.5 mm, 4.5-5.0 mm, 5.0-5.5 mm, etc. In other words, the set includes a first implant delivery system 12 for cross-sectional diameters in the range of 3.0 to 3.5 mm, having proximal markers 55a and 55b positioned axially so that the unfolded length LPP2 in a lumen of 3.0 to 3.5 mm is 5 mm; a second implant delivery system 102 for cross-sectional diameters in the range of 3.5 to 4.0 mm, having proximal markers 55a and 55b positioned axially so that the unfolded length LPP2 in a lumen of 3.5 to 4.0 mm is 5 mm; a third implant delivery system 102 for cross-sectional diameters in the range of 4.0 to 4.5 mm, having two proximal markers 55a and 55b positioned axially so that the unfolded length LPP2 in a lumen of 4.0 to 4.5 mm is 5 mm; and so on.

[0073] The method for selecting and using a long-distance implant delivery system 102 from a set of multiple implant delivery systems 102 is as follows: First, the cross-section of the proximal landing position 62 of the body lumen 90 is measured. The clinician then selects one of the implant delivery systems 102 from a set having a range that includes or encompasses the measured cross-section. For example, if the measured cross-section is 4.2 mm, an implant delivery system 102 with a range of 4.0–4.5 mm is selected. The selected implant delivery system 102 is then used in substantially the same manner as described above in relation to Figures 3A–3E, except that proximal portion markers 55a and 55b indicate this when the delivery catheter 40 has been withdrawn to the point of the final proximal portion 60. The position of the catheter distal end marker 52 where the determined shortened length LPP2 remains is based on the measured cross-section. If the measured cross-section is at the top of the cross-sectional range for the selected implant delivery system 102, the first proximal portion marker 55a indicates that the determined shortened length LPP2 remains unextended. If the measured cross section is at the lowest point of the cross section range for the selected implant delivery system 102, the second proximal portion marker 55b indicates that the determined shortened length LPP2 remains unextended. If the measured cross section is somewhere within the cross section range for the selected implant delivery system 102, the position proportionally located between the first proximal portion marker 55a and the second proximal portion marker 55b indicates that the determined shortened length LPP2 remains unextended. Thus, the clinician can estimate the appropriate position of the catheter distal end marker 52 relative to the first proximal portion marker 55a and the second proximal portion marker 55b, and then visualize the actual proximal landing position 62 of the final proximal portion 60 of the tubular implant 20. The clinician can determine whether the actual proximal landing position 62 of the tubular implant 20 is clinically desirable, and then extend or reposition the tubular member 20 as described above in relation to Figures 3A-3E.

[0074] Referring to Figures 6 and 7A–7B, another medical assembly 120 for delivering an expandable tubular implant 20 into a patient's target site is shown according to another embodiment of the disclosed invention. The medical assembly 120 is very similar to the medical assembly 10 described above, except that it includes a delivery system 122 having a tubular implant 20 having a proximal portion marker 57 which includes a radiopaque coil 57. The proximal portion marker 57 is attached to a delivery wire 80 or positioned on the tubular member 20. In the embodiments illustrated in Figures 6 and 7A–7B, the coil 57 is positioned such that the proximal end 59a of the coil 57 functions as a marker for the proximal portion indicating that a predetermined unfolded length LPP2 of the tubular member 20 remains unfolded. Alternatively, the proximal portion marker 57 may be axially positioned such that the distal end 59b of the coil 57 functions as a marker for the proximal portion indicating that a predetermined unfolded length LPP2 remains unfolded.

[0075] In another embodiment, the length of the coil 57 may also be configured such that the coil 57 functions similarly to the two markers 55a and 55b of the distant implant delivery system 102, in which case the proximal end 59a of the coil 57 functions like the second proximal portion marker 55b and the distal end 59b functions like the first proximal portion marker 55a. In this way, the delivery system 122 can be used for the same purposes as described herein for the delivery system 102.

[0076] The method of using the medical assembly 120 having the delivery system 122 is the same as that described herein for the medical assembly 10 having the delivery system 12. Furthermore, sets of multiple implant delivery systems 122 may be provided, as with the selection of implant delivery systems 12 and 102 described above. The method of selecting and using one implant delivery system 122 from a set of multiple implant delivery systems 122 is the same as or substantially similar to the method of selecting and using a set of implant delivery systems 12 or 102, as described herein.

[0077] While specific embodiments have been shown and described herein, it will be understood that these embodiments are not intended to limit the disclosed invention, and it will be clear that various changes and modifications (e.g., to the dimensions of various parts) can be made without departing from the scope of the disclosed invention, which should be defined solely by the claims and their equivalents. For example, it will be understood that elements or components shown herein with any embodiment may be used in or in combination with other embodiments disclosed herein. Therefore, this specification and the drawings should be considered illustrative, not restrictive.

Claims

1. An implant delivery system for implanting tubular implants into the body lumen, A delivery catheter comprising an elongated tubular member having a lumen, a proximal end, and an open distal end, A radiopaque first marker is positioned at the distal end of the opening of the delivery catheter, A tubular implant disposed within the lumen of the elongated tubular member, having a delivery length when folded within the delivery catheter and a shortened length when released outside the delivery catheter in a radially expanded implantation configuration, A pusher member slidably disposed within the delivery catheter, wherein the tubular implant is detachably coupled to the pusher member for delivery through the distal end of the opening of the delivery catheter. A radiopaque second marker is installed on one of the pusher member and the tubular implant, and is positioned such that when the delivery catheter is pulled into the tubular implant and the first marker is positioned at the second marker, the final proximal portion of the tubular implant, extending from the position of the second marker to the proximal end of the tubular implant, has a determined expanded length in a configuration in which it expands radially and contracts when inserted into the measured cross section of the body lumen at the target proximal landing position of the final proximal portion of the tubular implant. Equipped with an implant delivery system.

2. The implant delivery system according to claim 1, further comprising a radiopaque resheath marker positioned on the implant delivery system such that when the delivery sheath is withdrawn from the tubular implant, the first marker moves together with the delivery sheath with respect to the resheath marker, the resheath marker indicating the nearest position from which the first marker can be withdrawn, and beyond the nearest position, the delivery catheter cannot be advanced distally to resheat the tubular implant into the delivery catheter.

3. The implant delivery system according to claim 2, wherein the radiopaque second marker is positioned distal to the resheath marker along the implant delivery system.

4. The implant delivery system according to any one of claims 1 to 3, wherein the radiopaque second marker is positioned longitudinally in the implant delivery system based on a measured cross section of the body lumen at the target proximal landing position in order to provide the determined unfolded length of the final proximal portion of the tubular implant.

5. The implant delivery system according to any one of claims 1 to 3, wherein the radiopaque second marker is adjustable to set the determined unfolding length of the terminal proximal portion, and is adjustable on the pusher member or the tubular implant.

6. The implant delivery system according to any one of claims 1 to 3, wherein the radiopaque second marker is mounted on the pusher member.

7. The implant delivery system according to any one of claims 1 to 3, wherein the radiopaque second marker is positioned on the tubular implant.

8. The implant delivery system according to any one of claims 1 to 3, wherein the tubular implant is a stent or a flow diverter.

9. The implant delivery system according to any one of claims 1 to 3, wherein the tubular implant is self-expanding.

10. The implant delivery system according to any one of claims 1 to 3, wherein the measured cross-section of the body lumen at the target proximal landing site includes the average diameter of the body lumen along a portion of the body lumen at the target proximal landing site.

11. The implant delivery system according to any one of claims 1 to 3, wherein the measured cross-section of the body lumen at the target proximal landing position is based on a measurement of the cross-section of the body lumen at the target proximal landing position.

12. The implant delivery system according to any one of claims 1 to 3, wherein the measured cross-section of the body lumen at the target proximal landing position is based on an approximation using a standard cross-section of the body lumen.

13. The implant delivery system according to any one of claims 1 to 3, wherein the measured cross-section of the body lumen is at a proximal position to the target.

14. The implant delivery system according to any one of claims 1 to 3, wherein the determined expansion length is within the range of 2 to 5 mm.

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