STENT GRAFT DELIVERY SYSTEM
A system for treating an aneurysm comprises an elongate flexible shaft and an expandable member. An expandable scaffold is disposed over the expandable member and may be expanded from a collapsed configuration to an expanded configuration. A double-walled filling structure is disposed over the scaffold and has an outer wall and an inner wall. The filling structure is adapted to be filled with a hardenable fluid filing medium so that the outer wall conforms to an inside surface of the aneurysm and the inner wall forms a substantially tubular lumen to provide a path for blood flow. In the expanded configuration the scaffold engages the inner wall of the filling structure. A tether is releasably coupled with the filling structure and the flexible shaft thereby constraining axial movement of the structures relative to each other.
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The present application is a non-provisional of, and claims the benefit of U.S. Provisional Application No. 61/048,038 (Attorney Docket No. 025925-002600US), filed on Apr. 25, 2008, the full disclosure of which is incorporated herein by reference.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENTNOT APPLICABLE
REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISK.NOT APPLICABLE
BACKGROUND OF THE INVENTION1. Field of the Invention
The present invention relates generally to medical systems and methods for treatment. More particularly, the present invention relates to systems and methods for treating aneurysms.
Aneurysms are enlargements or “bulges” in blood vessels which are often prone to rupture and which therefore present a serious risk to the patient. Aneurysms may occur in any blood vessel but are of particular concern when they occur in the cerebral vasculature or the patient's aorta.
The present invention is particularly concerned with aneurysms occurring in the aorta, particularly those referred to as aortic aneurysms. Abdominal aortic aneurysms (AAA's) are classified based on their location within the aorta as well as their shape and complexity. Aneurysms which are found below the renal arteries are referred to as infrarenal abdominal aortic aneurysms. Suprarenal abdominal aortic aneurysms occur above the renal arteries, while thoracic aortic aneurysms (TAA's) occur in the ascending, transverse, or descending part of the upper aorta.
Infrarenal aneurysms are the most common, representing about eighty percent (80%) of all aortic aneurysms. Suprarenal aneurysms are less common, representing about 20% of the aortic aneurysms. Thoracic aortic aneurysms are the least common and often the most difficult to treat.
The most common form of aneurysm is “fusiform,” where the enlargement extends about the entire aortic circumference. Less commonly, the aneurysms may be characterized by a bulge on one side of the blood vessel attached at a narrow neck. Thoracic aortic aneurysms are often dissecting aneurysms caused by hemorrhagic separation in the aortic wall, usually within the medial layer. The most common treatment for each of these types and forms of aneurysm is open surgical repair. Open surgical repair is quite successful in patients who are otherwise reasonably healthy and free from significant co-morbidities. Such open surgical procedures are problematic, however, since access to the abdominal and thoracic aortas is difficult to obtain and because the aorta must be clamped off, placing significant strain on the patient's heart.
Over the past decade, endoluminal grafts have come into widespread use for the treatment of aortic aneurysm in patients who cannot undergo open surgical procedures. In general, endoluminal repairs access the aneurysm “endoluminally” through either or both iliac arteries in the groin. The grafts, which typically have been fabric or membrane tubes supported and attached by various stent structures, are then implanted, typically requiring several pieces or modules to be assembled in situ. Successful endoluminal procedures have a much shorter recovery period than open surgical procedures.
Present endoluminal aortic aneurysm repairs, however, suffer from a number of limitations. For example, a significant number of endoluminal repair patients experience leakage at the proximal juncture (attachment point closest to the heart) within two years of the initial repair procedure. While such leaks can often be fixed by further endoluminal procedures, the need to have such follow-up treatments significantly increases cost and is certainly undesirable for the patient. A less common but more serious problem has been graft migration. In instances where the graft migrates or slips from its intended position, open surgical repair is required. This is a particular problem since the patients receiving the endoluminal grafts are often those who are not considered to be good surgical candidates.
Further shortcomings of the present endoluminal graft systems relate to both deployment and configuration. For example, many of the commercially available endovascular systems are too large (above 12 F) for percutaneous introduction. Moreover, current devices often have an annular support frame that is stiff and difficult to deliver as well as unsuitable for treating many geometrically complex aneurysms, particularly infrarenal aneurysms with little space between the renal arteries and the upper end of the aneurysm, referred to as short-neck or no-neck aneurysms. Aneurysms having torturous geometries, are also difficult to treat.
For these reasons, it would be desirable to provide improved methods and systems for the endoluminal and minimally invasive treatment of aortic aneurysms. In particular, it would be desirable to provide systems having lower delivery profile and methods which can be delivered percutaneously and that can track and be deployed in tortuous vessels. It would also be desirable to provide prostheses with minimal or no endoleaks, which resist migration, which are flexible and relatively easy to deploy, and which can treat many if not all aneurismal configurations, including short-neck and no-neck aneurysms as well as those with highly irregular and asymmetric geometries. It would be further desirable to provide systems and methods which are compatible with current designs for endoluminal stents and grafts, including single lumen stents and grafts, bifurcated stents and grafts, parallel stents and grafts, as well as with double-walled filling structures which are the subject of the commonly owned, copending applications described below. It would also be desirable to provide systems and methods that provide feedback to the operator as to the positioning and deployment of the endoluminal repair device in the aneurysm. The systems and methods would preferably be deployable with the stents and grafts at the time the stents and grafts are initially placed. Additionally, it would be desirable to provide systems and methods for repairing previously implanted aortic stents and grafts, either endoluminally or percutaneously. At least some of these objectives will be met by the inventions described hereinbelow.
2. Description of the Background Art
U.S. Patent Publication No. 2006/0025853 describes a double-walled filling structure for treating aortic and other aneurysms. Copending, commonly owned U.S. Patent Publication No. 2006/0212112, describes the use of liners and extenders to anchor and seal such double-walled filling structures within the aorta. The full disclosures of both these publications are incorporated herein by reference. PCT Publication No. WO 01/21108 describes expandable implants attached to a central graft for filling aortic aneurysms. See also U.S. Pat. Nos. 5,330,528; 5,534,024; 5,843,160; 6,168,592; 6,190,402; 6,312,462; 6,312,463; U.S. Patent Publications 2002/0045848; 2003/0014075; 2004/0204755; 2005/0004660; and PCT Publication No. WO 02/102282.
BRIEF SUMMARY OF THE INVENTIONThe present invention provides systems and methods for the treatment of aneurysms, particularly aortic aneurysms including both abdominal aortic aneurysms (AAA) and thoracic aortic aneurysms (TAA). The systems may be introduced percutaneously or by surgical cutdown into a patient and may have an outer diameter ranging preferably from 10 French to 18 French and more preferably from 12 French to 16 French.
In a first aspect of the present invention, a system for treating an aneurysm in a blood vessel comprises an elongate flexible shaft having a proximal region and a distal region. A first double-walled filling structure is disposed over the distal region of the shaft and has an outer wall and an inner wall. The filling structure may be filled with a hardenable fluid filing medium so that the outer wall conforms to an inside surface of the aneurysm and the inner wall forms a first substantially tubular lumen to provide a path for blood flow. The system also includes a first expandable scaffold disposed adjacent the filling structure. The first scaffold is radially expandable within at least a portion of the tubular lumen of the filling structure and the filling structure is separate from the first scaffold and axially separated therefrom.
In some embodiments, the first scaffold may be proximal to the filling structure while in other embodiments, the first scaffold is distal to the filling structure. Sometimes there is a gap or spacing between one end of the first scaffold and one end of the filling structure. The first scaffold may be slidably received by the filling structure so that the first scaffold and the filling structure are concentric with one another, and the filling structure provides a covering around the scaffold.
Sometimes the delivery system may include a sheath that is disposed at least partially over the filling structure and/or the scaffold. The sheath may have a tapered tip and may have axially oriented slits. The system may also include a pusher tube that is disposed at least partially over the flexible shaft and that slidably engages with the first double-walled filling structure. A first tether may be coupled with the filling structure and the tether may extend between the proximal and distal regions of the flexible shaft. The tether may be adapted to guide movement of the first double-walled filling structure relative to the first scaffold axially along the shaft. The tether may also be used to pull the filling structure as it is axially moved relative to the first scaffold, thereby slidably engaging and positioning the filling structure with the first scaffold. Sometimes the delivery system may also comprise a second tether that is coupled with the filling structure and the second tether may extend between the proximal and distal regions of the flexible shaft. Systems may include one or more eyelets or suture loops coupled with the first filling structure and they may be adapted to receive the tethers or a tube and act as guides or the filling structure may comprise a receptacle coupled with a wall of the filling structure that can slidably receive a tube. The system may also include a nosecone coupled with the distal region of the flexible shaft and sometimes the tethers are coupled thereto. Portions of the tether may extend outside of a patient's body. The tether may be releasably coupled with the filling structure.
The system may further comprise an inflation device, such as a syringe, that is fluidly coupled with the filling structure and a pressure monitor. The pressure monitor may also be coupled with the filling structure so as to permit pressure monitoring of the filling structure as the filling structure is filled with the hardenable fluid filling medium. The pressure monitor may comprise a pressure gage, a digital display or the like.
Sometimes the filling structure comprises a relief valve and an optional reservoir may be fluidly coupled thereto. The relief valve may be fluidly isolated from the first filling structure and the reservoir may be adapted to receive the hardenable fluid filling medium from the relief valve at a predetermined pressure. The reservoir may be radiopaque when at least partially filled with the hardenable fluid filling medium. Other embodiments of the system may have a visual indicator fluidly coupled with the filling structure. The visual indicator may have first and second positions wherein the indicator moves from the first position to the second position when a predetermined pressure is applied to the visual indicator. This indicator may be visible under fluoroscopy.
Other embodiments may comprise a collapsible member such as a balloon that is fluidly coupled with a pressure gage. The collapsible member may be positioned between the outer wall of the filling structure and the inside surface of the aneurysm and thus the pressure gage indicates the pressure of the filling structure as it is filled. Other embodiments may also include a collapsible member such as a balloon that is similarly positioned between the aneurysm wall and the filling structure wall, and that is fluidly coupled with a compression mechanism, such as a spring, having first and second positions. The compression mechanism provides a predetermined force opposing the force exerted by the collapsible member as the filling structure is filled. The compression mechanism moves from the first position to the second position when the force exerted by the collapsible member exceeds the predetermined value. The collapsible member may be a balloon. Some systems may also include a locking mechanism which prevents fluid from filling the filling structure when the filling structure is filled to a predetermined pressure.
In some embodiments, the filling structure may comprise a compliant compartment that deforms as the outer wall of the filling structure conforms to the inside surface of the aneurysm. The compartment may have a substantially flat section and may be fluidly coupled with a pressure indicator.
Sometimes the first or second scaffold may comprise crushable regions and remainder regions. The crushable regions collapse when the filling structure is pressurized to a predetermined value while the remainder regions remain fully expanded. In yet other embodiments, the system may further comprise an expandable member such as a balloon, that expands from a contracted configuration to an expanded configuration and that is coupled with the shaft near the distal region. The expandable member may be fluidly coupled with a pressure monitoring device. The expandable member may have a pre-shaped, curved or tapered region.
The scaffold may be comprised of a metal and may be balloon expandable. The scaffold or filling structure may also carry a therapeutic agent that can be released therefrom in a controlled manner. Some therapeutic agents include anti-thrombogenics like heparin or agents which promote endothelial and smooth muscle cell growth, sealing and attachment. The filling structure may comprise a polymer.
The system may also comprise a second double-walled filling structure having an outer wall and an inner wall. The double-walled filling structure may be placed adjacent the first filling structure in the aneurysm and may be filled with a hardenable fluid filling medium so that the outer wall conforms to the inside surface of the aneurysm and to the first filling structure and forms a second generally tubular lumen to provide a path for blood flow. The system may also include a second scaffold separate from the first scaffold and the filling structures which can be expanded within at least a portion of the second tubular lumen of the second filling structure. The second scaffold may be axially separated from the second filling structure. Both the second scaffold and the second filling structure generally take the same form as the first scaffold and first filling structure. A flowable polymer that may be cured in situ may be used to as the filling material for both the first and second filling structures.
The system may also comprise a releasable coupling mechanism that is coupled with the first filling structure and the shaft. The coupling mechanism is adapted to reduce axial movement along the shaft of the filling structure relative to the scaffold. The releasable coupling mechanism may comprise a tether that is releasably coupled with the shaft and the filling structure. The filling structure may also comprise a filling tube that is fluidly coupled therewith and that is adapted to fill the filling structure with the filling medium. The filling tube may also comprise an inner tube that is slidably disposed in the filling tube. Both the inner tube and the filling tube may be fluidly coupled with the filling structure.
In another aspect of the present invention, a method for treating an aneurysm comprises providing an elongate flexible shaft having a proximal end and a distal end. The flexible shaft carries a first double-walled filling structure and a first scaffold adjacent the distal end. Advancing the elongate shaft in a patient's vasculature allows the first double-walled filling structure to traverse the aneurysm. Filling the first filling structure with a fluid filling medium expands the filling structure so that an outer wall of the first filling structure conforms to an inside surface of the aneurysm and an inner wall of the first filling structure forms a first substantially tubular lumen to provide a first blood flow path across the aneurysm. Axially moving the first scaffold relative to the first filling structure positions at least a portion of the first scaffold within the first substantially tubular lumen and radially expanding the first scaffold expands the first scaffold from a contracted configuration to an expanded configuration.
Axially moving the first scaffold may comprise moving the first scaffold distally into the first lumen or axially moving the first scaffold may comprise proximally retracting the first filling structure over the first scaffold. Axially moving the first scaffold may also comprise proximally retracting the first scaffold into the first lumen or moving the first filling structure distally over the first scaffold. Sometimes axially moving the first scaffold may comprise guiding the first filling structure over a tether line or pulling the first filling structure with a tether line. The method may also include retracting a sheath from the first filling structure or the first scaffolding so that that portion is unconstrained from expansion. The method may also comprise engaging a pusher tube with the first filling structure so as to prevent motion thereof. The method may also further comprise hardening the filling medium in the first filling structure.
The method may also include monitoring a pressure or controlling the filling of the first or second filling structures by changing pressure or volume of the filling medium. Filling the filling structure may comprise controlling pressure and/or volume of the filling medium. The pressure may be one that is exerted by the filling medium within the first filling structure. The monitored pressure may also be a pressure that is within a space between an external wall of the first filling structure and a wall of the aneurysm. Monitoring the pressure may include placing a fluid filled balloon catheter or a pressure transducer in the space between the filling structure and aneurysm wall. Often, the method may further include regulating flow of the filling medium in response to the monitored pressure.
Filling the filling structure may include actuating an injection device and pressure may be monitored at a position adjacent the injection device. The method also may include relieving pressure in the filling structure with a relief valve when the pressure exceeds a predetermined value. Sometimes, the relief valve may be fluidly isolated from the first filling structure. The fluid relieved from the filling structure may fill a reservoir that is fluidly coupled with the relief valve and an operator may observe the reservoir to determine inflation status of the filling structure. Some pressure monitoring devices may include a visual indicator that is coupled with the first filling structure. The indicator may have a first and a second position, and the indicator moves from the first position to the second position when a predetermined pressure is applied to the indicator. An operator may observe the indicator position to determine fillings status of the filling structure.
Other embodiments may include positioning a collapsible member such as a balloon between the outer wall of the filling structure and the inside wall of the aneurysm. An operator observes a compression mechanism having first and second positions that is coupled with the filling structure. The compression mechanism provides a predetermined force opposite to the force exerted by the collapsible member as the filling structure is filled and the compression mechanism moves from the first position to the second position when the force exerted by the collapsible member exceed the predetermined force. The compression mechanism may comprise a spring and the collapsible member may be comprise a balloon.
The method may also include the step of stopping the filling of the filling structure when the monitored pressure reaches a predetermined pressure. Stopping filling may be achieved by mechanically locking a filling device so that fluid may not be delivered therefrom. Monitoring pressure may also include observing the first scaffold. The first scaffold may have crushable regions and remainder regions and the crushable regions collapse when the filling structure is pressurized to a predetermined value while the remainder regions remain fully expanded.
The method may further comprise providing a second elongate flexible shaft having a proximal and distal end. The second shaft carries a second double walled filling structure and a second scaffold adjacent the distal end. Advancing the second elongate shaft in the patient's vasculature allows the second double walled filling structure to traverse the aneurysm. Filling the second filling structure with a fluid filling medium expands the filling structure so that an outer wall of the second filling structure forms a second substantially tubular lumen to provide a second blood flow path across the aneurysm. Filling the second filling structure may also comprise controlling pressure or volume of the fluid filling medium. Axially moving the second scaffold relative to the second filling structure positions at least a portion of the second scaffold within the second substantially tubular lumen and radially expanding the second scaffold expands the scaffold from a contracted configuration to an expanded configuration.
Axially moving the second scaffold may comprise moving the second scaffold distally into the second lumen or proximally retracting the second filling structure over the second scaffold. Axially moving the second scaffold may also comprise proximally retracting the second scaffold into the second lumen or moving the second filling structure distally over the second scaffold.
The method may also comprise retracting a sheath from either the second filling structure and/or the second scaffolding so that either or both are unconstrained from expansion. Retracting the sheath may also comprise splitting the sheath. The method also may comprise hardening the fluid filling medium in the second filling structure and monitoring a second pressure. The second pressure may be exerted by the filling medium in the second filling structure. Often, the flow of the filling medium may be regulated in response to the second monitored pressure. In some embodiments, the method may comprise filling either the first or the second filling structure until it engages the other filling structure resulting in filling medium being discharged from either the first or second filling structure. In still other embodiments, the method may comprise inflating a balloon on either the first or the second elongate shaft so as to compress the first and second filling structures against one another and against the aneurysm wall. Often filling medium will be discharged from either the first or second filling structure when the balloons are inflated. Radially expanding any of the scaffolds may comprise inflating a balloon disposed near the distal end of the shaft. The balloon may comprise a pre-shaped, curved or tapered region.
The method may also comprise releasing a releasable coupling mechanism that couples the filling structure with the shaft to allow axial movement of the filling structure relative to the scaffold and that also allows release of the filling structure from the shaft. Releasing the coupling mechanism may comprise releasing a knot in a tether joining the filling structure with the shaft. A filling tube may be fluidly coupled with the filling structure and the step of filling the filling structure may comprise passing fluid filling medium through the filling tube to the filling structure. The filling tube may comprise an inner tube that is slidably disposed therein and that is also in fluid communication with the filling structure. The method may comprise removing the inner tube and passing additional fluid filling medium through the filling tube after the inner tube has been removed.
In another aspect of the present invention, a system for treating an aneurysm in a blood vessel comprises an elongate flexible shaft having a proximal region and a distal region. An expandable member is disposed adjacent the distal region and a first expandable scaffold is disposed over the expandable member. The first scaffold is radially expandable from a collapsed configuration to an expanded configuration. A first double-walled filling structure is disposed over the first scaffold. The filling structure has an outer wall and an inner wall and the filling structure is adapted to be filled with a hardenable fluid filing medium so that the outer wall conforms to an inside surface of the aneurysm and the inner wall forms a first substantially tubular lumen to provide a path for blood flow. In the expanded configuration, the first scaffold engages the inner wall of the filling structure. A first releasable coupling mechanism releasably couples the filling structure with the flexible shaft and the coupling mechanism may comprise a tether that is releasably coupled with the filling structure and the flexible shaft. The coupling mechanism constrains axial movement of the filling structure relative to the flexible shaft.
The first tether may comprise a suture, and in some embodiments the system may include a lockwire disposed alongside the flexible shaft. A distal end of the lockwire may be releasably coupled with the flexible shaft. The flexible shaft may comprise a tapered nosecone having an aperture therein and the nosecone may be coupled with the distal region of the flexible shaft such that the distal end of the lockwire may be releasably coupled with and slidably received in the nosecone aperture. The first tether may be releasably coupled to the lockwire. The filling structure may include a first tether loop fixedly attached thereto, and the first tether may pass through the tether loop. The first tether loop may be disposed on a distal end of the filling structure. In some embodiments, the first tether may be releasably coupled to the lockwire with a knot such as a constrictor knot. One end of the first tether may be fixedly attached with the flexible shaft.
The system may further comprise a second releasable coupling mechanism. The second mechanism may comprise a tether that is releasably coupled with the filling structure and the flexible shaft. The second tether may be on an opposite end of the filling structure as the first tether, and the second tether may constrain axial movement of the filling structure relative to the flexible shaft. The second tether may comprise a suture and may be releasably coupled to the lockwire. The second tether may be looped around the lockwire. In some embodiments, the filling structure comprises a second tether loop fixedly attached thereto and disposed on an opposite end as the first tether loop, and the second tether may pass through the second tether loop. The second tether may be coupled to the flexible shaft and may be releasably coupled to the flexible shaft with a knot, such as a constrictor knot.
The system may further comprise a second releasable coupling mechanism, such as a tether that is releasably coupled with the filling structure and the flexible shaft. The second tether may be disposed on the same end of the filling structure as the first tether, and the second tether may constrain axial movement of the filling structure relative to the flexible shaft. The second tether may comprise a suture. In some embodiments, the system may further comprise a second lockwire disposed alongside the flexible shaft. A distal end of the second lockwire may be releasably coupled with the flexible shaft. The distal region of the flexible shaft may include a tapered nosecone having a second aperture and the distal end of the second lockwire may be releasably coupled with and slidably received in the second nosecone aperture. The second tether may be releasably coupled to the lockwire.
In some embodiments, the filling structure may comprise a second tether loop fixedly attached thereto, and wherein the second tether passes through the second tether loop. The second tether loop may be disposed on the same end of the filling structure as the first tether loop. The second tether may be releasably coupled to the lockwire with a knot such as a constrictor knot. One end of the second tether may be fixedly attached with the flexible shaft.
The system may further comprise a filling tube fluidly coupled with the filling structure. The filling tube may be adapted to deliver the hardenable filling medium to the filling structure. The filling tube may comprise a plurality of apertures near a distal end thereof and that are adapted to allow the hardenable filling medium to flow therethrough into the filling structure. The filling tube may comprise an inner filling tube and an outer filling tube slidably disposed thereover, both fluidly coupled with the filling structure. A stylet may be disposed in the filling tube. Some embodiments may include a filling tab fluidly coupled with the filling structure and fluidly coupled with the filling tube. The filling tab may comprise a scored region adapted to permit separation of the filling tab into two portions, the first portion remaining coupled with the filling structure after filling thereof with the hardenable filling medium and the second portion discrete and independent of the first portion.
In still other embodiments, the system may further comprise an outer sheath having a lumen. The filling structure, the scaffold and the expandable member may be disposed in the sheath lumen during delivery of the system to a treatment site. Other embodiments may include a second elongate flexible shaft having a proximal region and a distal region and a second expandable member disposed adjacent the distal region. A second expandable scaffold may be disposed over the second expandable member. The second scaffold may be radially expandable from a collapsed configuration to an expanded configuration. The system may also include a second double-walled filling structure disposed over the second scaffold. The second filling structure may have an outer wall and an inner wall, wherein the second filling structure is adapted to be filled with a hardenable fluid filing medium so that the outer wall conforms to an inside surface of the aneurysm and the inner wall forms a first substantially tubular lumen to provide a path for blood flow. The second scaffold in the expanded configuration may engage the inner wall of the filling structure, and the system may also have a tether releasably coupled with the second filling structure and the second flexible shaft. The tether may constrain axial movement of the second filling structure relative to the second flexible shaft.
In yet another aspect of the present invention, a method for treating an aneurysm in a patient comprises providing an elongate flexible shaft having a proximal end, a distal end, and an expandable member near the distal end. The flexible shaft carries a first radially expandable scaffold over the expandable member and a first double walled filling structure disposed over the first scaffold. Advancing the shaft in the vasculature of the patient allows the first filling structure to be delivered to the aneurysm. Radially expanding the first scaffold expands the scaffold from a contracted configuration to an expanded configuration, wherein in the expanded configuration the first scaffold engages the inner wall of the first filling structure. Filling the first filling structure with a first fluid filling medium allows an outer wall of the first filling structure to conform to an inside surface of the aneurysm and an inner wall of the first filling structure forms a first substantially tubular lumen to provide a first blood flow path across the aneurysm. Filling the first filling structure with the first fluid filling medium also allows assessment of the filling volume by removing and recording the first filling medium. Filling the first filling structure with a second fluid filling medium allows an outer wall of the first filling structure to conform to an inside surface of the aneurysm and an inner wall of the first filling structure forms a substantially tubular lumen to provide a first blood flow path across the aneurysm. The second fluid filling medium is hardened in the first filling structure and then the first filling structure is released from the flexible shaft. The flexible shaft is then retracted away from the first filling structure.
The method may further comprise pre-filling the first filling structure with a pre-filling fluid until the outer wall of the first filling structure conforms to the inside surface of the aneurysm, thereby unfurling the first filling structure. The pre-filling fluid may comprise saline and may be removed from the first filling structure. The method may also comprise pre-filling the first filling structure with pre-filling fluid until the outer wall of the first filling structure conforms to the inside surface of the aneurysm. The pressure and volume of the pre-filling fluid used to pre-fill the first filling structure may be measured and then the pre-filling fluid may be removed from the first filling structure. Filling the first filling structure with the first fluid filling medium may comprise filling the first filling structure with the first filling medium using substantially the same pressure and volume as measured. The pre-filling fluid may comprise saline or contrast media to assist visualizing the filling process under x-ray fluoroscopy. The first filling medium may be passed through a filling tube that is fluidly coupled with the first filling structure.
Radially expanding the scaffold may comprise inflating a balloon that is disposed on the flexible shaft. Hardening the first fluid filling medium in the first filling structure may comprise polymerizing the first fluid filling medium in situ. The first fluid filling medium may comprise polyethylene glycol.
A releasable coupling mechanism such as a tether may couple the first filling structure with the flexible shaft and the step of releasing the first filling structure from the flexible shaft may comprise releasing the coupling mechanism or de-coupling the tether from the first filling structure. One end of the tether may be releasably coupled with a lockwire and the step of de-coupling the tether may comprise retracting the lockwire thereby detaching the tether from the lockwire. De-coupling the tether may comprise releasing the tether from a tether loop on the first filling structure. In some embodiments, a second releasable coupling mechanism, such as a tether may couple the first filling structure with the flexible shaft and the step of releasing the first filling structure from the flexible shaft may comprise de-coupling the second tether from the first filling structure. Releasing one or more of the coupling mechanisms may permit separation of a filling tube from the filling structure.
The method may further comprise the step of retracting a sheath away from the first filling structure and the first scaffold to allow expansion thereof. Pressure may be monitored during filling of the first filling structure. The monitored pressure may be a pressure of the filling medium in the first filling structure or a pressure in a space between the outer wall of the first filling structure and a wall of the aneurysm. A filling tube may be released from the first filling structure after the hardenable filling medium has been delivered thereto. Releasing the filling tube may comprise severing a filling tab coupled with the first filling structure.
In some embodiments, the method may further comprise providing a second elongate flexible shaft having a proximal end, a distal end, and a second expandable member near the distal end. The second flexible shaft may carry a second radially expandable scaffold over the second expandable member and a second double walled filling structure may be disposed over the second scaffold. The second shaft may be advanced in the vasculature of the patient so that the second filling structure is delivered to the aneurysm and the second filling structure is filled with a second fluid filling medium so that an outer wall of the second filling structure conforms to an inside surface of the aneurysm and an inner wall of the second filling structure forms a second substantially tubular lumen to provide a second blood flow path across the aneurysm. The second scaffold is radially expanded from a contracted configuration to an expanded configuration wherein in the expanded configuration the second scaffold engages the inner wall of the second filling structure. The second fluid filling medium may be hardened in the second filling structure and the second flexible shaft is released from the second filling structure. The second shaft may be retracted away from the second filling structure.
The first filling structure may comprise a filling tube that is fluidly coupled therewith and the step of filling the first filling structure may comprise passing filling medium through the filling tube. The filling tube may comprise an inner tube that is slidably disposed therein and that is also fluidly coupled with the filling structure. The method may further comprise removing the inner tube from the filling tube and supplying additional filling medium to the filling structure by passing the filling medium through the filing tube after the inner tube has been removed therefrom.
These and other embodiments are described in further detail in the following description related to the appended drawing figures.
Referring now to
In a particular and preferred aspect of the present invention, a pair of double-walled filling structures will be used to treat infrarenal abdominal aortic aneurysms, instead of only a single filling structure as illustrated in
Alternatively, one or both filling structures 112, 212 may be filled with a hardenable material and then the filling structures 112, 212 are radially expanded along with the corresponding scaffold 127, 227. In still other embodiments, combinations of filling and expanding may be performed in different order depending on physician preference and aneurysm anatomy. In some embodiments, an optional unfurling of the filling structure may be performed prior its filling and radial expansion. In this optional step, once the delivery system is positioned across the aneurysm, the filling structure may be filled with CO2 gas, contrast media, saline or other fluids to unfurl the filling structure away from the delivery catheter thereby helping to ensure more uniform filling later on. During unfurling, the filling structure may be partially filled or fully filled so that it conforms to the inner aneurysm wall. Once unfurled, the fluid may be removed from the filling structure and it may be filled with the hardenable material to expand and conform to the aneurismal space between the lumens and the inner aneurysm wall. Pressure relief valves such as those described below may also be used to ensure that the filling structure is not over filled.
In another variation of the method, an optional contrast pre-filling step may be utilized. In this embodiment, after the delivery catheter is positioned across the aneurysm and the endoframe has been radially expanded, the filling structure may be pre-filled with contrast media so as to permit observation of the filled filling structure under a fluoroscope relative to the aneurismal sac. Additionally, the pre-filling step allows the physician to record the pressure and volume of the contrast media used for optimal filling of the filling structure and this will provide an estimate of volume and pressure to be used when filling the filling structure with the hardenable filling material. In order to prevent overfilling of the filling structure, any of the pressure relief valves disclosed below may also be used to bleed off excess fluid from the filling structure.
After filling the filling structures 112 and 212 as illustrated in
The double filling structure embodiments will include at least one separate scaffold deployed within each of the tubular blood flow lumens. The scaffolds will generally be endoskeletal structures that lay the foundation for new lumens, and will be deployed within the tubular lumens of the double-walled filling structures using balloon or other expansion catheters (in the case of malleable or balloon-expandable scaffolds) and an optional retractable constraining sheath.
Referring now to
In the exemplary embodiment of
In use, once the filling structure 2902 and the endoframe 2904 have been delivered to a desired position, the lockwire 2918 may be retracted proximally so that its distal tip disengages from aperture 2920 and the lockwire is removed from under the constrictor knot 2916 allowing the knot to unfurl. This de-couples the endoframe 2902 from the delivery catheter 2908 so that the two may be separated from one another. One end of the tether remains coupled with the catheter so that the tether may also be removed from the body.
The embodiment of
The coupling mechanism described in
In other embodiments, the filling structure may be coupled more directly with the endoframe. For example, in
In place of tethers coupled with the filling tube (such as tether 3128 in
In addition to the potential challenge of minimizing movement of the endoframe relative to the filling structure, the embodiment described in
Another embodiment which reduces the need for two delivery catheters and also reduces procedure time by eliminating the need to remove the catheter from the patient and then mount a scaffold thereover is illustrated in
Yet another embodiment that helps reduce delivery profile is illustrated by system 390 in
Some delivery systems may include a sheath. Any of the embodiments previously described may include a sheath in order to protect the scaffolding and/or the filling structure. In some embodiments where the scaffolding is self-expanding, the sheath acts as a constraint to keep the scaffolding from self-expanding.
Other variations on the orientation of the balloon, filling structure and scaffolding may also be employed. For example, in some embodiments the endoframe scaffolding and filling structure may be mounted coaxially over a catheter shaft either proximal of or distal to a balloon. The scaffolding and filling structure are positioned at the treatment site and then the balloon is positioned within the scaffolding and filling structure and expanded. In a variation of this embodiment, a thin split tubular liner may be positioned over the balloon and passes through the inner diameter of the filling structure. The thin liner acts as a guide for the balloon during use. Thus, as the balloon is axially positioned within the scaffolding and filling structure, the thin liner guides the balloon through the inner diameter of the scaffolding. When the balloon is expanded, the thin liner splits along perforations or slit regions to allow radial expansion thereof.
For example, in
A split sheath or a perforated sheath may also be used to facilitate deployment of the device. For example,
In other embodiments, a tether line may be used to help guide movement of the filling structure relative to the scaffolding.
A hitch may also be used to move the filling structure relative to the scaffolding.
Sometimes, it may be desirable to increase the columnar strength of the endograft in order to prevent it from buckling or otherwise collapsing. Suturing the endograft to the scaffold may be used to help keep the two structures coupled together. Some embodiments utilize wires or metal frames in the filling structure or attached thereto in order to provide additional support. A pocket or receptacle on the filling structure may also provide enhanced column strength.
In
Another exemplary embodiment of a filling structure and scaffolding delivery system is seen in
Many of the filling structure embodiments include a filling tube.
A double filling tube may be used to avoid some of the challenges discussed above. In
The filling tubes may have many geometries. They may be round, rectangular or other configurations. Generally, it is preferred that the filling tubes have a low profile in order to maintain a low delivery diameter of the entire system. For example, in
It can be challenging to maintain an airtight seal between the filling structure and the removable filling tube. Additionally, when the filling medium hardens, it can be challenging to separate the filling tube from the filling structure after in situ curing.
Various modifications of the protocols described above will be within the scope of the present invention. For example, while some of the scaffolds have been shown as being delivered at the same time as deployment of the filling structure(s), it will also be possible to deliver the scaffolds after deployment of the filling structures. The scaffolds could be delivered on the same or different delivery catheter(s) used to deliver and/or shape the filling structures. The scaffolds could then be expanded before, during or after filling the filling structure.
Pressure monitoring can also be performed at various stages of the aneurysm repair procedure to help control the filling process of the filling structure. The monitoring of pressures serves to reduce the risk of dissection, rupture or damage to the aneurysm from over-pressurization and also can be used to determine an endpoint for filling. Monitoring can be done before, during or after filling and hardening of the filling structure with filling medium. Specific pressures which can be monitored include the pressure within the internal space of the filling structure as well as the pressure in the space between the external walls of the filling structure and the inner wall of the aneurysm. A composite measurement can also be made combining pressures such as those measured within the interior space of the filling structure, together with that in the space between the external walls of the structure and the aneurysm wall or other space at the aneurysm site and an external delivery pressure used by a fluid delivery device, such as a pump or syringe, to deliver the filling medium. Control decisions can be made using any one of these pressure measurements or a combination thereof. U.S. patent application Ser. No. 11/482,503 (Attorney Docket No. 025925-001410US) discloses a number of pressure measuring embodiments, the entire contents of which are incorporated herein by reference.
For example, in
Similar to the filling tube, the angiography catheter should also have a low profile but it's lumen should also have as large a cross-sectional area in order to allow easy, low pressure delivery of contrast media at very high flow rates, 500-1,000 cc/minute.
In an exemplary method of deploying a filling structure and scaffolding, pressure monitoring may be utilized in the following way. After two filling structures have been delivered to the treatment site, both scaffolds are radially expanded to help create a lumen for blood flow through the filling structure across the aneurysm. Using data from a patient's computerized tomography (CT) scans, a fill volume of the aneurysm treatment site may be estimated and then divided by two, half for each of the two filling structures. This represents the baseline filling volume for each filling structure and is the minimum volume of filling material to be injected into each of the filling structures. Syringes or other injection devices coupled with a pressure gage may be used to optionally pre-fill each filling structure with contrast material using the baseline volume and the resulting baseline fill pressure may be noted. This allows unfurling of the filling structure and provides a preliminary assessment of how the expanded filling structures fit into the aneurismal space. Once this is accomplished, the contrast material is removed from the filling structures. Again using the patient CT data, a functional fill volume may be determined. This volume is a percentage of the aneurysm volume obtained from the CT data, or it may be a predetermined number and is the volume of filling material that effectively seals and excludes the aneurysm. Functional fill pressure will be the pressure at which the functional fill volume is attained. A polymer fill dispenser may then be used to fill each filling structure with the functional fill volume and the functional fill pressure is noted. While holding the functional fill volume and pressure, the filling structure may be observed under fluoroscopy to check for proper positioning, filling and the absence of leakage across the aneurysm. If leaks are observed, additional polymer may be added to the filling structures until the leaks are prevented or minimized. Excessive additional polymer should not be added to the filling structure in order to avoid exceeding a safe fill volume or safe fill pressure. Once the physician is satisfied with the filling and positioning of the filling structures, stopcocks to the filling structures may be closed to allow the polymer to harden and then the delivery devices may be removed from the patient.
In addition to actual pressure monitoring by gages and graphical displays, etc., other pressure indicators may also be used to facilitate determining the filling status of the filling structure.
While the use of a pressure relief valve such as described with respect to
Some embodiments do not utilize a pressure relief valve and therefore other ways of masking the pressure line from pressure spikes are also desirable. For example, when an electronic pressure transducer is used, a low pass filter may be used to eliminate the pressure spike observed during actuation of the filling device. Additionally, electronic recording devices may be set to calculate and display the average pressure over a longer period of time (e.g. sample pressure over 20 seconds rather than 2 seconds), or sampling frequency may be reduced. This will effectively eliminate the pressure spike or “mask” it out and the resulting pressure display is a value that more closely indicates pressure of the filling structure. An exemplary embodiment of a pressure gage that masks pressure spikes is illustrated in
Placing a fluid filled balloon tipped catheter in the space between the filling structure and the aneurysm wall allows the pressure exerted by the filling structure against the aneurysm wall to be measured, and this is illustrated in
In addition to monitoring pressure of a balloon 524 placed between the filling structure and the aneurysm wall, other pressure indicators may be used to determine when to stop filling the filling structure.
The balloon 546 and pressure indicator 544 may be integrated with a filling mechanism or the two may be separate from one another.
Instead of a separate balloon catheter placed between the filling structure and aneurysm wall, the filling structure may include a separate compartment that acts like the balloon catheter previously described in
The scaffolding itself may also be used to indicate the filling status of the filling structure. In
In still another embodiment, the balloon used to radially expand the scaffolding may also be used to monitor pressure. In
Other embodiments may control filling of the filling structures by using either a balloon on the delivery catheter or the filling structures themselves. For example, in
While the above is a complete description of the preferred embodiments of the invention, various alternatives, modifications, and equivalents may be used. The various features of the embodiments disclosed herein may be combined or substituted with one another. Therefore, the above description should not be taken as limiting in scope of the invention which is defined by the appended claims.
Claims
1. A system for treating an aneurysm in a blood vessel, the system comprising:
- an elongate flexible shaft having a proximal region and a distal region;
- a first double-walled filling structure disposed over the distal region of the shaft, the filling structure having an outer wall and an inner wall, wherein the filling structure is adapted to be filled with a hardenable fluid filing medium so that the outer wall conforms to an inside surface of the aneurysm and the inner wall forms a first substantially tubular lumen to provide a path for blood flow; and
- at least a first expandable scaffold disposed adjacent the filling structure, the first scaffold radially expandable within at least a portion of the tubular lumen of the filling structure,
- wherein the filling structure is separate from the first scaffold and axially separated therefrom.
2. The system according to claim 1, wherein the first scaffold is proximal to the filling structure.
3. The system according to claim 1, wherein the first scaffold is distal to the filling structure.
4. The system according to claim 1, wherein a spacing exists between one end of the first scaffold and one end of the filling structure.
5. The system according to claim 1, wherein the first scaffold is slidably received by the filling structure such that the first scaffold and the filling structure are concentric with one another.
6. The system according to claim 1, further comprising a sheath disposed at least partially over the filling structure.
7. The system according to claim 1, further comprising a sheath disposed at least partially over the scaffold.
8. The system according to claim 1, further comprising a tapered sheath disposed at least partially over the flexible shaft.
9. The system according to claim 8, wherein the tapered sheath comprises axially oriented slits near a distal end thereof.
10. The system according to claim 1, further comprising a pusher tube disposed at least partially over the flexible shaft and slidably engageable with the first double-walled filling structure.
11. The system according to claim 1, further comprising a first tether coupled with the filling structure, the tether adapted to guide movement of the first double-walled filling structure relative to the first scaffold axially along the shaft.
12. The system according to claim 11, wherein the first tether extends between the proximal and distal regions of the flexible shaft.
13. The system according to claim 11, wherein the filling structure is slidably engaged with the first tether.
14. The system according to claim 11, further comprising a second tether coupled with the filling structure.
15. The system according to claim 14, wherein the second tether extends between the proximal and distal regions of the flexible shaft.
16. The system according to claim 11, wherein the filling structure comprises one or more eyelets.
17. The system according to claim 11, further comprising a nosecone coupled with the distal region of the flexible shaft, wherein the tether is coupled with the nosecone.
18. The system according to claim 11, wherein a portion of the tether extends outside of a patient's body.
19. The system according to claim 11, wherein the tether is releasably coupled with the filling structure.
20. The system according to claim 1, wherein the filling structure comprises a receptacle coupled with a wall of the filling structure, the receptacle adapted to slidably receive a tube.
21. The system according to claim 1, further comprising a pressure monitor, the pressure monitor coupled with the filling structure so as to permit pressure monitoring of the filling structure as the filling structure is filled with the hardenable fluid filling medium.
22. The system according to claim 21, wherein the pressure monitor is fluidly coupled with the filling structure.
23. The system according to claim 21, wherein the pressure monitor comprises a pressure gage.
24. The system according to claim 21, wherein the pressure monitor comprises a digital display or waveform monitor.
25. The system according to claim 1, further comprising an inflation device fluidly coupled with the filling structure.
26. The system according to claim 25, wherein the inflation device comprises a syringe.
27. The system according to claim 1, wherein the filling structure comprises a relief valve.
28. The system according to claim 27, wherein the filling structure comprises a reservoir fluidly coupled with the relief valve
29. The system according to claim 28, wherein the reservoir is adapted to receive the hardenable fluid filling medium from the relief valve at a predetermined pressure.
30. The system according to claim 29, wherein the reservoir is radiopaque when the reservoir is at least partially filled with the hardenable fluid filling medium.
31. The system according to claim 27, wherein the relief valve is fluidly isolated from the first filling structure.
32. The system according to claim 1, wherein the filling structure comprises a visual indicator fluidly coupled therewith and having first and second positions, wherein the indicator moves from the first position to the second position when a predetermined pressure is applied to the visual indicator.
33. The system according to claim 32, wherein the indicator is visible under fluoroscopy.
34. The system according to claim 1, further comprising a collapsible member fluidly coupled with a pressure gage, the expandable member positioned between the outer wall of the filling structure and the inside surface of the aneurysm, the pressure gage adapted to indicate pressure of the filling structure as it is filled.
35. The system according to claim 34, wherein the collapsible member comprises a balloon.
36. The system according to claim 1, further comprising a collapsible member positioned between the outer wall of the filling structure and the inside wall of the aneurysm, the collapsible member fluidly coupled with a compression mechanism having a first position and a second position, the compression mechanism adapted to provide a predetermined force opposing the force exerted by the collapsible member as the filling structure is filled, the compression mechanism moving from the first position to the second position when the force exerted by the collapsible member exceeds the predetermined force.
37. The system according to claim 36, wherein the compression mechanism comprises a spring.
38. The system according to claim 36, wherein the collapsible member comprises a balloon.
39. The system according to claim 1, further comprising a locking mechanism, wherein the locking mechanism prevents fluid from filling the filling structure when the filling structure is filled to a predetermined pressure.
40. The system according to claim 1, wherein the filling structure comprises a compliant compartment adapted to deform as the outer wall of the filling structure conforms to the inside surface of the aneurysm.
41. The system according to claim 40, wherein the compartment is fluidly coupled with a pressure indicator.
42. The system according to claim 35, wherein the balloon comprises a substantially flat section.
43. The system according to claim 1, wherein the first scaffold comprises crushable regions and remainder regions, the crushable regions adapted to collapse when the filling structure is pressurized to a predetermined value while the remainder regions remain fully expanded.
44. The system according to claim 1, further comprising an expandable member expandable from a contracted configuration to an expanded configuration and coupled with the shaft near the distal region.
45. The system according to claim 44, wherein the expandable member comprises a balloon.
46. The system according to claim 45, wherein the balloon comprises a pre-shaped, curved or tapered region.
47. The system according to claim 44, wherein the expandable member is coupled to a pressure monitoring device.
48. The system according to claim 1, wherein the scaffold is balloon expandable.
49. The system according to claim 1, wherein the scaffold comprises a metal.
50. The system according to claim 1, wherein the scaffold or the filling structure carries a therapeutic agent adapted to being released therefrom in a controlled manner.
51. The system according to claim 1, wherein the filling structure comprises a polymer.
52. The system according to claim 1, further comprising a releasable coupling mechanism coupled with the first filling structure and the shaft, wherein the coupling mechanism is adapted to reduce relative axial movement along the shaft of the first filling structure relative to the first scaffold.
53. The system according to claim 52, wherein the releasable coupling mechanism comprises a tether releasably coupled with the shaft and the first filling structure.
54. The system according to claim 1, wherein the first filling structure comprises a filling tube fluidly coupled therewith and adapted to fill the filling structure with the filling medium.
55. The system according to claim 54, wherein the filling tube comprises an inner tube slidably disposed in the filling tube, both the inner tube and the filling tube fluidly coupled with the filling structure.
56. The system according to claim 1, further comprising:
- a second double-walled filling structure having an outer wall and an inner wall, wherein said second double-walled filling structure is adapted to be placed adjacent the first filling structure in the aneurysm and to be filled with a hardenable fluid filling medium so that the outer wall conforms to the inside surface of the aneurysm and to the first filling structure and forms a second generally tubular lumen to provide a path for blood flow; and
- at least a second scaffold separate from the first scaffold and the filling structures which can be expanded within at least a portion of the second tubular lumen of the second filling structure,
- wherein the second scaffold is axially separated from the second filling structure.
57. The system according to claim 56, wherein the second scaffold is balloon expandable.
58. The system according to claim 56, wherein the second scaffold comprises a metal.
59. The system according to claim 56, wherein the second filling structure comprises a polymer.
60. The system according to claim 1, further comprising a flowable polymer filling material curable in situ.
61. A method for treating an aneurysm, said method comprising:
- providing an elongate flexible shaft having a proximal end and a distal end, the flexible shaft carrying a first double-walled filling structure and a first scaffold adjacent the distal end;
- advancing the elongate shaft in a patient's vasculature such that the first double-walled filling structure traverses the aneurysm;
- axially moving the first scaffold relative to the first filling structure such that at least a portion of the first scaffold is disposed within the first double-walled filling structure;
- radially expanding the first scaffold from a contracted configuration to an expanded configuration; and
- filling the first filling structure with a fluid filling medium so that an outer wall of the first filling structure conforms to an inside surface of the aneurysm and an inner wall of the first filling structure forms a first substantially tubular lumen to provide a first blood flow path across the aneurysm, and wherein the at least a portion of the first double-walled filling structure is disposed in the first substantially tubular lumen.
62. The method of claim 61, wherein axially moving the first scaffold comprises moving the first scaffold distally into the first lumen.
63. The method of claim 61, wherein axially moving the first scaffold comprises proximally retracting the first filling structure over the first scaffold.
64. The method of claim 61, wherein axially moving the first scaffold comprises proximally retracting the first scaffold into the first lumen.
65. The method of claim 61, wherein axially moving the first scaffold comprises moving the first filling structure distally over the first scaffold.
66. The method of claim 61, wherein axially moving the first scaffold comprises guiding the first filling structure over a tether line.
67. The method of claim 61, wherein axially moving the first scaffold comprises pulling the first filling structure with a tether line.
68. The method of claim 61, further comprising retracting a sheath from the first filling structure so that the first filling structure is unconstrained from expansion.
69. The method of claim 68, wherein retracting the sheath comprises splitting the sheath.
70. The method of claim 61, further comprising retracting a sheath from the first scaffolding so that the first scaffolding is unconstrained from expansion.
71. The method of claim 61, further comprising hardening the fluid filling medium in the first filling structure.
72. The method of claim 61, further comprising engaging a pusher tube with the first filling structure thereby preventing movement thereof.
73. The method of claim 61, further comprising monitoring a pressure.
74. The method of claim 73, wherein the pressure is exerted by the filling medium within the first filling structure.
75. The method of claim 61, wherein the step of filling the filling structure comprises controlling pressure or volume of the fluid filling medium.
76. The method of claim 73, wherein the monitored pressure is within a space between an external wall of the first filling structure and a wall of the aneurysm.
77. The method of claim 76, wherein monitoring the pressure comprises placing a catheter in the space.
78. The method of claim 77, wherein the catheter comprises a fluid filled balloon.
79. The method of claim 76, wherein monitoring the pressure comprises placing a pressure transducer in the space.
80. The method of claim 73, wherein filling the filling structure comprises actuating an injection device and wherein the pressure is monitored at a position adjacent the injection device.
81. The method of claim 73, further comprising relieving pressure in the filling structure with a relief valve when the pressure exceeds a predetermined value.
82. The method of claim 81, further comprising filling a reservoir fluidly coupled with the relief valve.
83. The method of claim 82, further comprising observing the reservoir.
84. The method of claim 81, further comprising isolating the relief valve from the first filling structure so that the relief valve is fluidly isolated therefrom.
85. The method of claim 73, further comprising observing a visual indicator coupled with the first filling structure, the indicator having first and second positions, wherein the indicator moves from the first position to the second position when a predetermined pressure is applied to the visual indicator.
86. The method of claim 73, further comprising positioning a collapsible member between the outer wall of the filling structure and the inside wall of the aneurysm and further comprising observing a compression mechanism having a first position and a second position, the compression mechanism adapted to provide a predetermined force opposing the force exerted by the collapsible member as the filling structure is filled, the compression mechanism moving from the first position to the second position when the force exerted by the collapsible member exceeds the predetermined force.
87. The method of claim 86, wherein the compression mechanism comprises a spring.
88. The method of claim 86, wherein the collapsible member comprises a balloon.
89. The method of claim 73, further comprising stopping the filling of the filling structure when the monitored pressure reaches a predetermined pressure.
90. The method of claim 89, wherein stopping the filling comprises mechanically locking a filling device so that fluid may not be delivered therefrom.
91. The method of claim 73, wherein monitoring comprises observing the first scaffold, the first scaffold comprising crushable regions and remainder regions, the crushable regions adapted to collapse when the filling structure is pressurized to a predetermined value while the remainder regions remain fully expanded.
92. The method of claim 61, wherein the step of radially expanding the first scaffold comprises inflating a balloon disposed near the distal end of the elongate shaft.
93. The method of claim 92, wherein the balloon comprises a pre-shaped, curved or tapered region.
94. The method of claim 61, further comprising releasing a releasable coupling mechanism that couples the filling structure with the shaft to allow axial movement of the filling structure relative to the first scaffold and to allow release of the filling structure from the shaft.
95. The method of claim 94, wherein releasing the coupling mechanism comprises releasing a knot in a tether joining the filling structure with the shaft.
96. The method of claim 61, wherein a filling tube is fluidly coupled with the filling structure, and the step of filling the filling structure comprises passing the fluid filling medium through the filling tube to the filling structure.
97. The method of claim 96, wherein the filling tube comprises an inner tube slidably disposed therein and in fluid communication with the filling structure, the method further comprising removing the inner tube and passing additional fluid filling medium through the filling tube after the inner tube has been removed.
98. The method of claim 61, further comprising:
- providing a second elongate flexible shaft having a proximal and distal end, the second shaft carrying a second double-walled filling structure and a second scaffold adjacent the distal end;
- advancing the second elongate shaft in the patient's vasculature such that the second double-walled filling structure traverses the aneurysm;
- axially moving the second scaffold relative to the second filling structure such that at least a portion of the second scaffold is disposed within the second double-walled filling structure;
- filling the second filling structure with a fluid filling medium so that an outer wall of the second filling structure forms a second substantially tubular lumen to provide a second blood flow path across the aneurysm, and wherein at least a portion of the second scaffold is disposed in the second substantially tubular lumen; and
- radially expanding the second scaffold from a contracted configuration to an expanded configuration.
99. The method of claim 98, wherein axially moving the second scaffold comprises moving the second scaffold distally into the second lumen.
100. The method of claim 98, wherein axially moving the second scaffold comprises proximally retracting the second filling structure over the second scaffold.
101. The method of claim 98, wherein axially moving the second scaffold comprises proximally retracting the second scaffold into the second lumen.
102. The method of claim 98, wherein axially moving the second scaffold comprises moving the second filling structure distally over the second scaffold.
103. The method of claim 98, further comprising retracting a sheath from the second filling structure so that the second filling structure is unconstrained from expansion.
104. The method of claim 103, wherein retracting the sheath comprises splitting the sheath.
105. The method of claim 98, further comprising retracting a sheath from the second scaffolding so that the second scaffolding is unconstrained from expansion.
106. The method of claim 98, further comprising hardening the fluid filling medium in the second filling structure.
107. The method of claim 98, further comprising monitoring a second pressure, the second pressure being exerted by the filling medium within the second filling structure.
108. The method of claim 98, wherein the step of filling the second filling structure comprises controlling pressure or volume of the fluid filling medium.
109. The method of claim 98, further comprising inflating a balloon on either the first or second elongate shaft so as to compress the first and second filling structures against one another and against the aneurysm wall.
110. The method of claim 109, wherein filling medium is discharged from either the first or second filling structure.
111. The method of claim 98, further comprising filling either the first or the second filling structure until it engages the other filling structure resulting in filling medium being discharged from either the first or second filling structure.
112. The method of claim 98, wherein the step of radially expanding the second scaffold comprises inflating a balloon disposed near the distal end of the second shaft.
113. The method of claim 112, wherein the balloon on the second shaft comprises a pre-shaped, curved or tapered region.
114. A system for treating an aneurysm in a blood vessel, said system comprising:
- an elongate flexible shaft having a proximal region and a distal region;
- an expandable member disposed adjacent the distal region;
- a first expandable scaffold disposed over the expandable member, the first scaffold radially expandable from a collapsed configuration to an expanded configuration;
- a first double-walled filling structure disposed over the first scaffold, the filling structure having an outer wall and an inner wall, wherein the filling structure is adapted to be filled with a hardenable fluid filing medium so that the outer wall conforms to an inside surface of the aneurysm and the inner wall forms a first substantially tubular lumen to provide a path for blood flow,
- wherein the first scaffold in the expanded configuration engages the inner wall of the filling structure; and
- a first releasable coupling mechanism releasably coupling the filling structure with the flexible shaft, wherein the coupling mechanism constrains axial movement of the filling structure relative to the flexible shaft.
115. The system of claim 114, wherein the releasable coupling mechanism comprises a first tether.
116. The system of claim 115, wherein the tether comprises a suture.
117. The system of claim 115, further comprising a lockwire disposed alongside the flexible shaft, wherein a distal end of the lockwire is releasably coupled with the flexible shaft.
118. The system of claim 117, wherein the flexible shaft comprises a tapered nosecone having an aperture therein, the nosecone coupled with the distal region of the flexible shaft, and wherein the distal end of the lockwire is releasably coupled with and slidably received in the nosecone aperture.
119. The system of claim 117, wherein the first tether is releasably coupled to the lockwire.
120. The system of claim 119, wherein the filling structure comprises a first tether loop fixedly attached thereto, and wherein the first tether passes through the tether loop.
121. The system of claim 120, wherein the first tether loop is disposed on a distal end of the filling structure.
122. The system of claim 119, wherein the first tether is releasably coupled to the lockwire with a knot.
123. The system of claim 122, wherein the knot comprises a constrictor knot.
124. The system of claim 115, wherein one end of the first tether is fixedly attached with the flexible shaft.
125. The system of claim 117, further comprising a second releasable coupling mechanism releasably coupled with the filling structure and the flexible shaft, the second coupling mechanism disposed on an opposite end of the filling structure as the first coupling mechanism, and wherein the second coupling mechanism constrains axial movement of the filling structure relative to the flexible shaft.
126. The system of claim 125, wherein the second coupling mechanism comprises a second tether.
127. The system of claim 126, wherein the second tether comprises a suture.
128. The system of claim 126, wherein the second tether is releasably coupled to the lockwire.
129. The system of claim 128, wherein the second tether is looped around the lockwire.
130. The system of claim 126, wherein the filling structure comprises a second tether loop fixedly attached thereto and disposed on an opposite end as the first tether loop, and wherein the second tether passes through the second tether loop.
131. The system of claim 126, wherein the second tether is coupled to the flexible shaft.
132. The system of claim 131, wherein the second tether is releasably coupled to the flexible shaft with a knot.
133. The system of claim 132, wherein the knot comprises a constrictor knot.
134. The system of claim 125, wherein the first filling structure comprises a fill tube fluidly coupled therewith, and wherein the second coupling mechanism is coupled with the fill tube so as to prevent release of the fill tube from the filling structure.
135. The system of claim 114, further comprising a second releasable coupling mechanism releasably coupled with the filling structure and the flexible shaft, wherein the second mechanism is disposed on the same end of the filling structure as the first releasable coupling mechanism, and wherein the second mechanism constrains axial movement of the filling structure relative to the flexible shaft.
136. The system of claim 135, wherein the second mechanism comprises a second tether.
137. The system of claim 136, wherein the second tether comprises a suture.
138. The system of claim 136, further comprising a second lockwire disposed alongside the flexible shaft, wherein a distal end of the second lockwire is releasably coupled with the flexible shaft.
139. The system of claim 138, wherein the flexible shaft comprises a tapered nosecone having a second aperture therein, the nosecone coupled with the distal region of the flexible shaft, and wherein the distal end of the second lockwire is releasably coupled with and slidably received in the second nosecone aperture.
140. The system of claim 138, wherein the second tether is releasably coupled to the lockwire.
141. The system of claim 136, wherein the filling structure comprises a second tether loop fixedly attached thereto, and wherein the second tether passes through the second tether loop.
142. The system of claim 141, wherein the second tether loop is disposed on the same end of the filling structure as the first tether loop.
143. The system of claim 138, wherein the second tether is releasably coupled to the lockwire with a knot.
144. The system of claim 143, wherein the knot comprises a constrictor knot.
145. The system of claim 136, wherein one end of the second tether is fixedly attached with the flexible shaft.
146. The system of claim 114, further comprising a filling tube fluidly coupled with the filling structure, the filling tube adapted to deliver the hardenable filling medium to the filling structure.
147. The system of claim 146, wherein the filling tube comprises a plurality of apertures near a distal end thereof, the apertures adapted to allow the hardenable filling medium to flow therethrough into the filling structure.
148. The system of claim 146, wherein the filling tube comprises an inner filling tube and an outer filling tube slidably disposed thereover, both inner and outer tubes fluidly coupled with the filling structure.
149. The system of claim 146, further comprising a stylet disposed in the filling tube.
150. The system of claim 146, further comprising a filling tab fluidly coupled with the filling structure and fluidly coupled with the filling tube.
151. The system of claim 150, wherein the filling tab comprises a scored region adapted to permit separation of the filling tab into two portions, the first portion remaining coupled with the filling structure after filling thereof with the hardenable filling medium and the second portion discrete and independent of the first portion.
152. The system of claim 114, further comprising an outer sheath having a lumen, wherein the filling structure, the scaffold and the expandable member are disposed with the sheath lumen during delivery of the system to a treatment site.
153. The system of claim 114, wherein the expandable member comprises an inflatable balloon.
154. The system of claim 153, wherein the balloon comprises a pre-shaped, curved or tapered region.
155. The system of claim 114, further comprising a pressure monitor, the pressure monitor coupled with the first filling structure so as to permit pressure monitoring of the filling structure as the filling structure is filled with the hardenable fluid filling medium.
156. The system of claim 114, further comprising:
- a second elongate flexible shaft having a proximal region and a distal region;
- a second expandable member disposed adjacent the distal region;
- a second expandable scaffold disposed over the second expandable member, the second scaffold radially expandable from a collapsed configuration to an expanded configuration;
- a second double-walled filling structure disposed over the second scaffold, the second filling structure having an outer wall and an inner wall, wherein the second filling structure is adapted to be filled with a hardenable fluid filing medium so that the outer wall conforms to an inside surface of the aneurysm and to the first double-walled filling structure, and the inner wall forms a first substantially tubular lumen to provide a path for blood flow,
- wherein the second scaffold in the expanded configuration engages the inner wall of the filling structure; and
- a tether releasably coupled with the second filling structure and the second flexible shaft, wherein the tether constrains axial movement of the second filling structure relative to the second flexible shaft.
157. A method for treating an aneurysm in a patient, said method comprising:
- providing an elongate flexible shaft having a proximal end, a distal end, and an expandable member near the distal end, the flexible shaft carrying a first radially expandable scaffold over the expandable member and a first double walled filling structure disposed over the first scaffold;
- advancing the shaft in the vasculature of the patient so that the first filling structure is delivered to the aneurysm;
- filling the first filling structure with a first fluid filling medium so that an outer wall of the first filling structure conforms to an inside surface of the aneurysm and an inner wall of the first filling structure forms a first substantially tubular lumen to provide a first blood flow path across the aneurysm;
- radially expanding the first scaffold from a contracted configuration to an expanded configuration, wherein in the expanded configuration the first scaffold engages the inner wall of the first filling structure;
- hardening the fluid filling medium in the first filling structure;
- releasing the first filling structure from the flexible shaft; and
- retracting the flexible shaft away from the first filling structure.
158. The method of claim 157, further comprising:
- pre-filling the first filling structure with a pre-filling fluid until the outer wall of the first filling structure conforms to the inside surface of the aneurysm, thereby unfurling the first filling structure; and
- removing the pre-filling fluid from the first filling structure.
159. The method of claim 158, wherein the pre-filling fluid comprises saline.
160. The method of claim 158, further comprising:
- pre-filling the first filling structure with pre-filling fluid until the outer wall of the first filling structure conforms to the inside surface of the aneurysm;
- measuring the pressure and volume of the pre-filling fluid used to pre-fill the first filling structure; and
- removing the pre-filling fluid from the first filling structure, wherein the step of filling the first filling structure with the first fluid filling medium comprises filling the first filling structure with the first filling medium using substantially the same pressure and volume as measured.
161. The method of claim 160, wherein the pre-filling fluid comprises saline.
162. The method of claim 160, wherein the pre-filling fluid comprises contrast media.
163. The method of claim 158, wherein the step of filling the first filling structure comprises passing the first fluid medium through a filling tube fluidly coupled with the first filling structure.
164. The method of claim 157, wherein the first filling structure comprises a filling tube fluidly coupled therewith, and the step of filling the first filling structure comprises passing the filling medium through the filling tube.
165. The method of claim 164, wherein the filling tube comprises an inner tube slidably disposed therein and fluidly coupled with the first filling structure, the method further comprising removing the inner tube from the filling tube and supplying additional filling medium to the filling structure by passing the additional filling medium through the filling tube after the inner tube has been removed therefrom.
166. The method of claim 157, wherein the step of radially expanding the scaffold comprises inflating a balloon disposed on the flexible shaft.
167. The method of claim 166, wherein the balloon comprises a pre-shaped, curved or tapered region.
168. The method of claim 157, wherein the step of hardening the first fluid filling medium in the first filling structure comprises polymerizing the first fluid filling medium in situ.
169. The method of claim 168, wherein the first fluid filling medium comprises polyethylene glycol.
170. The method of claim 157, wherein a releasable coupling mechanism couples the first filling structure with the flexible shaft and the step of releasing the first filling structure from the flexible shaft comprises releasing the coupling mechanism from the first filling structure.
171. The method of claim 170, wherein the coupling mechanism comprises a tether and the step of releasing the coupling mechanism comprises detaching the tether from the first filling structure.
172. The method of claim 171, wherein one end of the tether is releasably coupled with a lockwire and the step of de-coupling the tether comprises retracting the lockwire thereby detaching the tether from the lockwire.
173. The method of claim 171, wherein detaching the tether comprises releasing the tether from a tether loop on the first filling structure.
174. The method of claim 171, wherein a second releasable coupling mechanism couples the first filling structure with the flexible shaft and the step of releasing the first filling structure from the flexible shaft comprises de-coupling the second coupling mechanism from the first filling structure.
175. The method of claim 171, wherein the first filling structure comprises a fill tube fluidly coupled therewith, and wherein a second releasable coupling mechanism is coupled with the fill tube such that the step of releasing the first filling structure from the flexible shaft comprises de-coupling the second coupling mechanism from the fill tube to allow separation of the fill tube from the filling structure.
176. The method of claim 157, further comprising the step of retracting a sheath away from the first filling structure and the first scaffold to allow expansion thereof.
177. The method of claim 157, further comprising the step of monitoring a pressure during filling of the first filling structure.
178. The method of claim 177, wherein the pressure comprises a pressure of the filling medium in the first filling structure.
179. The method of claim 177, wherein the pressure comprises a pressure in a space between the outer wall of the first filling structure and a wall of the aneurysm.
180. The method of claim 157, further comprising releasing a filling tube from the first filling structure.
181. The method of claim 180, wherein the step of releasing the filling tube comprises severing a filling tab coupled with the first filling structure.
182. The method of claim 157, further comprising:
- providing a second elongate flexible shaft having a proximal end, a distal end, and a second expandable member near the distal end, the second flexible shaft carrying a second radially expandable scaffold over the second expandable member and a second double walled filling structure disposed over the second scaffold;
- advancing the second shaft in the vasculature of the patient so that the second filling structure is delivered to the aneurysm;
- filling the second filling structure with a second fluid filling medium so that an outer wall of the second filling structure conforms to an inside surface of the aneurysm and to the first double-walled filling structure, and an inner wall of the second filling structure forms a second substantially tubular lumen to provide a second blood flow path across the aneurysm;
- radially expanding the second scaffold from a contracted configuration to an expanded configuration, wherein in the expanded configuration the second scaffold engages the inner wall of the second filling structure;
- hardening the second fluid filling medium in the second filling structure;
- releasing the second filling structure from the second flexible shaft; and
- retracting the second shaft away from the second filling structure.
Type: Application
Filed: Apr 24, 2009
Publication Date: Feb 11, 2010
Applicant: Nellix, Inc. (Palo Alto, CA)
Inventors: Steven L. Herbowy (Palo Alto, CA), Michael A. Evans (Palo Alto, CA), Anant Kumar (San Jose, CA), K.T. Venkateswara Rao (San Jose, CA), Matthew R. Hellewell (Menlo Park, CA), Gil Laroya (Santa Clara, CA)
Application Number: 12/429,474
International Classification: A61M 31/00 (20060101); A61M 29/00 (20060101); A61B 5/00 (20060101);