Endovascular aneurysm treatment device and method
An self-expanding frame is mounted on the distal end of a shaft. The frame is sized and configured so that it can be inserted into the cavity of an aneurysm. Suction is applied to the interior of the aneurysm through the shaft or through another catheter, and the wall of the aneurysm is collapsed onto the exterior surface of the frame. The frame is then collapsed upon further suction being applied to the interior of the aneurysm, which collapses the aneurysm wall with it. The frame folds down on itself, carrying with it the aneurysm wall. The frame is detachable from the shaft and can be left in the collapsed aneurysm.
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This application is related to and claims priority under 35 U.S.C. §119 to U.S. provisional patent application Ser. No. 60/224,361, filed Aug. 11, 2000, the entire contents of which are incorporated by reference herein.
BACKGROUND OF THE INVENTION1. Field of the Invention
The present invention relates to systems and processes for treating an aneurysm, and more particular to an endovascular system and process for collapsing an aneurysm.
2. Discussion of Related Art
Aneurysm treatments have been proposed using a wide variety of processes and devices, which have enjoyed various levels of success and acceptance. Such systems and processes include aneurysm clips, intravascular coils, intravascular injections, detachable intravascular balloons, and the like.
These prior devices, however, have proven to be difficult to employ, oftentimes do not lend themselves to deployment in all sizes of aneurysms, can be imprecise in their deployment, their installation can be very time consuming, risk rupture of the aneurysm because they increase its size, can risk recanalization and/or migration of the device in the patient's vasculature, and may not treat the mass effect that the aneurysm may have caused. Furthermore, the present of adhesions in the aneurysm makes it difficult to collapse the aneurysm. There therefore remains an unmet need in the art for systems and processes which do not suffer from one or more of these deficiencies.
SUMMARY OF THE INVENTIONAccording to a first aspect of the invention, a method of treating an aneurysm in a patient comprises the steps of advancing a compressed clip through the distal end of a catheter and into the aneurysm, expanding portions of the clip inside the aneurysm, and folding a distal segment of the clip on itself together with the adjacent wall of the aneurysm as it becomes dislodged from the stretching bar.
According to a second aspect of the invention, a system useful for treating an aneurysm in a blood vessel of a mammalian patient, the aneurysm having a neck, a wall, and a cavity, comprises an elongated shaft having a proximal end, a distal end, a longitudinal direction defined between the proximal end and the distal end, and including at least one lumen extending therethrough, and a self-expanding frame positioned at the distal end of the shaft, the frame including a plurality of self-expanding sections and at least one joint, each of the plurality of self-expanding sections having an unbiased, expanded condition and a biased, collapsed condition, each of the plurality of self-expanding sections being foldable about one of the at least one joint when in a biased, collapsed condition.
According to a third aspect of the invention, a catheter useful for accessing a vascular location adjacent to an aneurysm, comprises a hollow shaft including a proximal end, a distal end, a longitudinal direction defined between the proximal end and the distal end, a port in a distal portion of the shaft, and including at least one lumen extending therethrough, and an inflatable member mounted on the shaft adjacent to the shaft distal end, the inflatable member in fluid communication with the shaft at least one lumen, the inflatable member including a proximal end, a distal end, and a wall between the proximal end and the distal end which extends to the shaft so that the shaft port is directly exposed to the exterior of the balloon, the wall delimiting a central working channel.
According to a fourth aspect of the invention, a method of treating an aneurysm in a patient comprises the steps of advancing a compressed clip through the distal end of a catheter and into the aneurysm, expanding portions of the clip inside the aneurysm, and folding a distal segment of the clip on itself together with the adjacent wall of the aneurysm as it becomes dislodged from the stretching bar.
Still other objects, features, and attendant advantages of the present invention will become apparent to those skilled in the art from a reading of the following detailed description of embodiments constructed in accordance therewith, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGSThe invention of the present application will now be described in more detail with reference to preferred embodiments of the apparatus and method, given only by way of example, and with reference to the accompanying drawings, in which:
Apparatus and methods in accordance with the present invention have numerous advantages over prior aneurysm clips and methods. Among these advantages, immediate closure of an aneurysm can be achieved with a relatively easy-to-use method. The apparatus and methods can be used to treat all aneurysms regardless of the size or the neck width, and can achieve precise locational deployment and decreased procedure time. The risk of rupture can be decreased, since the aneurysm volume is never increased. Additionally, occlusion of the aneurysm neck can be achieved by a balloon in case rupture does occur. Decreased risk of distal embolization, little or no risk of recanalization or migration, strengthening of the arterial wall at the site of the aneurysm, good visualization of the device during and after deployment, and immediate elimination of any mass effect the aneurysm may have caused can also be achieved.
Referring to the drawing figures, like reference numerals designate identical or corresponding elements throughout the several figures.
The system 100 also preferably includes a flexible portion in the distal end of the catheter 102 so that the catheter can more easily navigate the sometimes tortuous paths encountered during endovascular procedures. By way of example and not of limitation, a spring 120 can be incorporated into the distal portions of the catheter 102, preferably proximal of the balloon 112, to permit the catheter to more easily flex and bend. A pair of steering wires 122 are attached to the catheter distal to the flexible portion 120 and to a steering mechanism or station 124 at the proximal end of the catheter. Steering mechanisms for catheters have previously been proposed in the patent literature, and therefore a detailed description of station 124 will be omitted herein.
The catheter 102 also preferably includes at least one, and more preferably several distal side perfusion holes 126 which are in fluid communication with one of the three lumenae, e.g., lumen 110. The catheter also includes a one way valve 128 positioned distally of the balloon 112 and also in fluid communication with one of the lumenae. Valve 128 is oriented to permit a vacuum drawn in the catheter to suction through the valve, for purposes which will be explained in greater detail below. In accordance with one preferred embodiment, both the side holes 126 and the valve 128 are in fluid communication with the same lumen; because the one way valve 128 only permits flow into the catheter through the valve, perfusion of fluid, e.g. contrast agent, through the side holes 126 will not exit out the catheter through the valve.
Turning briefly to
The stretching bar 118 includes at least one, and preferably several telescoping sections 132a-f of decreasing outer diameter. Thus, section f can slide into section e, section e into section d, and so forth, when the wire 130 is pulled proximally. The clip 116 includes at least one, and preferably several rings 134a-f which are releasably held on the outer surface of the stretching bar 118, e.g., by a friction fit, a frangible coupling, or the like. To each ring 134 a set of arms 136 are attached so that the arms can articulate and fold in toward the stretching bar, in a manner somewhat similar to an umbrella. An outer trellis or covering 138 extends between the opposite ends of the arms.
In order to deploy the clip 116, the distal end of the catheter 102 is positioned in the neck of an aneurysm, as illustrated in
According to additional embodiments, the releasable connections between the arms 136 and the stretching bar 118 can be formed as twist locks, meltable connections, for which a resistive heater is positioned at each arm and voltage source is connected thereto, or the like as will be readily appreciated by one of ordinary skill in the art.
Turning now to
The stiffening wire or stretching bar 210 extends longitudinally through the shaft 202. The wire or bar 210 allows the practitioner to straighten or laterally collapse the frame 206; that is, when the bar/wire/mandrel 210 is pushed distally against the distal end 204, the frame 206 can be stretched and collapsed, and proximal retraction removes this force on the frame and permits the frame to expand. Self-expanding frames are well known to those of skill in the art, such as those known for use in constructing vascular stents, and therefore the constructional details of frame 206 are omitted from this description for brevity's sake. As described in greater detail below, the self-expanding frame is constrained from expanding when advanced through the vasculature because the frame is carried in a catheter shaft which is sized to prevent the frame from expanded until the clip is moved out of the catheter. Such a practice is also known in the art of vascular stents, which are typically carried in a collapsed condition inside a carrier catheter, and thereafter pushed out of the catheter which permits them to expand.
Preferably, at least portions of the shaft 202 are configured so that upon rotation of the shaft about the longitudinal axis, the shaft is released from the frame 206. By way of example and not of limitation, distal portions of the shaft 202 can include a detent which will pass through correspondingly sized and shaped holes in the sections of the frame 206 only when the shaft is rotated to align the detent and hole. Other suitable mechanisms will be readily apparent to those of skill in the art.
The catheter 220 also preferably includes a mechanism or the like which directs a clip radially outward through the working channel 228 when the clip is pushed distally through the shaft 222. According to one exemplary embodiment, this mechanism can be a ramp shaped surface formed in the lumen of the shaft 222, so that when the clip is pushed distally through the shaft, the clip's distal motion is converted into radial motion out of the shaft and into the working channel. According to yet another exemplary embodiment, a deflectable tube 234 can be mounted on the shaft at the base of the working channel 228, and a steering thread 232 is attached to the tube 234. The steering thread extends proximally through the shaft 222 and exits the shaft or is otherwise made available to the practitioner to manipulate. Upon proximal pulling on the steering thread 232, the tube 236 can be deflected to point toward the central working channel 228, thus directing any clip, such as clip 200, which is pushed through the tube 234 into the working channel.
Several lumenae extend through the shaft 222. A suction lumen 236 extends from a distal port 248, located where the working channel 228 meets the shaft 222, to a proximal fitting or suction end 238, and includes a lock 242. The lock 242 is operable to seal the lumen 236 so that a relative vacuum can be maintained in the lumen. For example, lock 242 can be a stopcock valve. A proximal fitting 244 leads to another lumen of the shaft 222, and is the lumen which leads to the deflectable tube 234 and is the lumen in which the clip, e.g., clip 200, is longitudinally advanceable. Thus, the clip 200 can be loaded through the fitting 244 or the tube 234, into the shaft 222 with proximal portions of the clip extending proximally out of the fitting 244. In this orientation, the clip is in a collapsed condition because the internal dimensions of the lumen are selected to constrain the clip from self-expanding. Thereafter, the clip can be advanced distally through the tube 234 and laterally into the working channel 228.
Turning now to
Another aspect of the present invention includes methods of treating an aneurysm. Several embodiments of methods in accordance with the present invention will now be described with reference to several of the drawing figures, and with reference to several of the exemplary devices described herein. The methods of the present invention are not restricted to the particular devices described herein, but may be performed using other devices which are employable into an aneurysm cavity and onto the outer surface of which the aneurysm wall can be collapsed. By way of example and not of limitation, vascular coils, such as those described in the numerous U.S. patents to Guglielmi et al (see, e.g., U.S. Pat. No. 6,083,220), can be used as a device in the methods of the present invention.
A first exemplary embodiment of a method in accordance with the present invention, given by way of example and not of limitation, includes, but is not limited to, the steps of:
-
- 1. Perform a road-mapping arteriogram with measurement of the three dimensional size of an aneurysm 10 and its neck 12.
- 2. Access the aneurysm neck using a steerable catheter, e.g. catheter 102.
- 3. Lock the distal end of the catheter in a position perpendicular to the center of the neck transverse axis.
- 4. Slowly inflate a balloon mounted on the distal end of the catheter with a diluted contrast medium up to the previously measured size of the neck. (see
FIG. 2 ) - 5. Verify complete occlusion of the neck 12 by injection of contrast agent through side holes in the catheter positioned just proximal to the balloon, and simultaneously applying suction through a one-way valve at the distal end of the catheter. When no inflow of the contrast into the catheter is demonstrated together with deformation of the aneurysm with the suction, the aneurysm neck is completely closed.
- 6. With the neck completely closed, continue suction to almost complete collapse of the aneurysm by creating a vacuum within the aneurysm. (see
FIG. 3 ) - 7. Obtain transverse and longitudinal measurement of the aneurysm, e.g. using MRI, CT scan, or the like.
- 8. Advance a compressed clip, the size of which has been chosen according to the previous measurements, through the distal end of the catheter. The clip, which is constructed using a principal similar to a self-expanding vascular stent, will start to expand as it is advanced into the aneurysm. The transverse axis of the clip is preferably maintained parallel to the longitudinal axis of the artery 14 from which the aneurysm 10 is arising. (see
FIGS. 4 and 5 ) - 9. Maintain the vacuum within the aneurysm with continuous suction to ensure adherence of the aneurysm wall to the sides of the clip. (
FIG. 6 a) - 10. Begin proximal pulling of the wire or thread mounted within the stretching bar to telescope the very distal segment into the next proximal segment. (see
FIG. 6 b) - 11. The distal segment of the clip, which folds on itself if not stretched from both ends as described above, will start folding on itself together with the adjacent wall of the aneurysm as it becomes dislodged from the stretching bar. (see
FIG. 6 c) The aneurysm wall is held to the outside of the clip by the suction. - 12. By repeating the process described in steps 10 and 11, successive segments of the stretching bar and clip will continue to fold and complete collapse of the aneurysm will be achieved. (see
FIG. 7 ) The catheter can then be withdrawn.
A second exemplary embodiment of a method in accordance with the present invention, given by way of example and not of limitation, includes, but is not limited to, the steps of:
-
- 1. Perform a road-mapping arteriogram.
- 2. Obtain measurements of the aneurysm, the neck of the aneurysm, and the parent artery.
- 3. Using a transvascular approach, e.g., a right femoral approach, position the balloon catheter 200 in the parent artery (using the guidance of the radiopaque markers on the periphery of the central working channel) with the distal segment of the balloon distal, e.g., immediately distal, of the aneurysm neck, and the proximal segment proximal, e.g., immediately proximal, to the aneurysm neck (see
FIGS. 9-11 ) - 4. Slowly inflate the balloon to achieve occlusion of the parent artery both proximal and distal to the neck.
- 5. Pull the steering thread within the catheter shaft to direct the steerable section of the catheter to a position as close and as perpendicular as possible to the neck (see
FIG. 12 ). - 6. Apply a moderate amount of suction using a suitable device, e.g., a syringe attached to a lock mounted on the proximal end of the catheter to decompress the aneurysm; activate the lock to maintain the relative vacuum in the aneurysm (see
FIG. 10 ). - 7. Stiffen the distal segment of the aneurysm clip with the stiffening wire by pulling on the proximal segment of the wire and then push it until it reaches the sealed top of the clip.
- 8. Push both the stiffening wire and the clip into the aneurysm cavity, firmly holding both of these elements together; the self-expanding frame of the clip will start to expand as the clip is deployed (see
FIG. 13 ). - 9. Apply strong suction through the catheter to collapse the aneurysm wall completely around the expanded clip (see
FIG. 14 ). - 10. Turn off the vacuum lock at the proximal end of the catheter while applying strong vacuum to the catheter lumen to ensure that a vacuum is maintained within the aneurysm to assist, and preferably ensure, that the aneurysm wall adheres to the outside of the clip.
- 11. Start pulling the stiffening wire through the sealed proximal end of the catheter to release the most distal segment of the clip, which will fold onto itself about the joint because of the action of the springs in the joints, together with the adjacent aneurysm wall which is held by the vacuum (see
FIGS. 15, 16 ), which may be at least in part assisted by the force of the vacuum pushing inward on the frames of the clip. - 12. Repeat steps 10 and 11 so that successive segments or sections of the clip continue to fold and at least partial, and preferably complete, collapse of the aneurysm will be achieved (see
FIG. 17 ). - 13. Rotate the shaft, e.g., counterclockwise, to dislodge the shaft from the collapsed segment(s) of the clip.
A third exemplary embodiment of a method in accordance with the present invention, given by way of example and not of limitation, includes, but is not limited to, the steps of the above described second embodiment, with the following modification. The clip is positioned at the neck of the aneurysm and the very proximal end of the aneurysm segment. Only the portion of the clip that is in the aneurysm is folded, leaving the rest of the aneurysm decompressed but not fully collapsed onto the outer surface of the clip (see
A fourth exemplary embodiment of a method in accordance with the present invention, given by way of example and not of limitation, includes, but is not limited to, utilizing the clip 300 (see
-
- 1. Perform steps 1-6 as described in the second embodiment above.
- 2. Introduce the distal segment of the clip to a point just distal of the neck of the aneurysm, i.e., just inside the aneurysm cavity (see
FIG. 25 ). - 3. Apply strong suction and lock it in to maintain vacuum in the aneurysm cavity.
- 4. Pull the distal segment of the clip to push (fold) down the aneurysm neck (see
FIG. 26 ). - 5. Introduce the proximal segment of the clip into the parent artery, e.g., through a catheter 220, just proximal of the neck and permit or cause the joint of the proximal segment to collapse (see
FIG. 27 ). - 6. Dislodge the pushing wire by turning it, e.g., in a counterclockwise direction (see
FIG. 28 ).
As will be readily appreciated by one of skill in the, the present invention also extends to the combination of a deployment catheter, such as catheter 220, with any of the embodiments of the aneurysm clips described herein to access and treat an aneurysm.
While the invention has been described in detail with reference to preferred embodiments thereof, it will be apparent to one skilled in the art that various changes can be made, and equivalents employed, without departing from the scope of the invention. Each of the aforementioned published documents is incorporated by reference herein in its entirety.
Claims
1. A system useful for treating an aneurysm in a blood vessel of a mammalian patient, the aneurysm having a neck, a wall, and a cavity, comprising:
- an elongated catheter having a proximal end, a distal end, and including at least one lumen extending therethrough;
- a telescoping stretching rod positioned in the catheter;
- at least one steering pull wire extending distally through the catheter and attached adjacent to the distal end of the catheter;
- an inflatable member positioned adjacent the catheter distal end;
- a one-way valve positioned adjacent the catheter distal end and in fluid communication with the at least one lumen, the one-way valve oriented to permit fluid flow into the catheter lumen;
- an expandable clip releasably attached to the catheter distal end, the expandable clip having an unbiased, expanded condition and a biased, collapsed condition;
- wherein when the expandable clip is positioned inside the cavity of an aneurysm and expands, when the inflatable member is inflated to substantially seal the neck of the aneurysm from the blood vessel, and when suction is applied through the catheter lumen and through the one-way valve, the aneurysm wall at least partially collapses on the expanded clip.
2. A system in accordance with claim 1, further comprising:
- a flexible spring positioned adjacent the catheter distal end, the spring including a distal end, at least one steering pull wire attached to the catheter adjacent to the spring distal end.
3-7. (canceled)
8. A catheter useful for accessing a vascular location adjacent to an aneurysm, comprising:
- a hollow shaft including a proximal end, a distal end, a longitudinal direction defined between the proximal end and the distal end, a port in a distal portion of the shaft, and including at least one lumen extending therethrough;
- an inflatable member mounted on the shaft adjacent to the shaft distal end, the inflatable member in fluid communication with the shaft at least one lumen, the inflatable member including a proximal end, a distal end, and a wall between the proximal end and the distal end which extends to the shaft so that the shaft port is directly exposed to the exterior of the balloon, the wall delimiting a central working channel.
9. A catheter in accordance with claim 8, further comprising:
- a longitudinally movable steering wire extending along the shaft; and
- a deflectable tube mounted at the shaft port, the steering wire attached to the deflectable tube so that when the steering wire is pulled proximally, the deflectable tube deflects laterally.
10. A catheter in accordance with claim 8, further comprising:
- a suction port on a distal portion of the shaft directly exposed to the exterior of the balloon; and
- a suction lumen extending through the shaft from the shaft proximal end to the suction port.
11. A catheter in accordance with claim 8, further comprising:
- at least one radiopaque marker mounted immediately adjacent to the central working channel.
12. A method of treating an aneurysm in a patient comprising the steps of:
- advancing a compressed clip through the distal end of a catheter and into the aneurysm;
- expanding portions of the clip inside the aneurysm;
- folding a distal segment of the clip on itself together with the adjacent wall of the aneurysm as it becomes dislodged from the stretching bar.
13. A method in accordance with claim 12, further comprising verifying complete occlusion of the neck by injection of contrast agent through multiple side holes just proximal to the balloon and simultaneously applied suction through the one-way valve at the distal end of the catheter until no inflow of the contrast is demonstrated together with deformation of the aneurysm with suction, indicating that the aneurysm neck is completely closed.
14. A method in accordance with claim 13, further comprising continuing suction with the aneurysm neck completely closed to almost completely collapse the aneurysm by creating a vacuum within the aneurysm.
15. A method in accordance with claim 12, further comprising measuring transverse and longitudinal dimensions of the aneurysm.
16. A method in accordance with claim 13, further comprising maintaining vacuum within the aneurysm with continuous suction and adhering the aneurysm wall to sides of the clip.
17. A method in accordance with claim 16, further comprising repeating the pulling step until successive segments fold and complete collapse of the aneurysm is achieved.
18. A method in accordance with claim 12, further comprising performing a road-mapping arteriogram with measurement of the three dimensional size of the aneurysm and its neck.
19. A method in accordance with claim 12, further comprising accessing the aneurysm neck using a steerable catheter.
20. A method in accordance with claim 19, further comprising locking the distal end of the catheter in a position perpendicular to the center of the neck transverse axis.
21. A method in accordance with claim 12, further comprising inflating a balloon mounted on the distal end of a catheter with a diluted contrast to the previously measured size of the neck.
22. A method in accordance with claim 12, further comprising:
- pulling a stretching bar to telescope a very distal segment of the stretching bar into the next proximal segment of the stretching bar.
23. A system useful for treating an aneurysm in a blood vessel of a mammalian patient, the aneurysm having a neck, a wall, and a cavity, comprising:
- an elongated shaft having a proximal end, a distal end, a longitudinal direction defined between the proximal end and the distal end, and including at least one lumen extending therethrough;
- a self-expanding frame positioned at the distal end of the shaft, the frame including a plurality of self-expanding sections disposed in the longitudinal direction, each of said self-expanding sections being connected to an adjacent self-expanding section via a separate joint, each of the plurality of self-expanding sections having an unbiased, expanded condition and a biased, collapsed condition, each of the plurality of self-expanding sections being foldable in the longitudinal direction and about the separate joint when in a biased, collapsed condition,
- wherein the at least one joint being oriented longitudinally when the plurality of self-expanding sections are in the unbiased, expanded condition.
24. A system useful for treating an aneurysm in a blood vessel of a mammalian patient, the aneurysm having a neck, a wall, and a cavity, comprising:
- an elongated shaft having a proximal end, a distal end, a longitudinal direction defined between the proximal end and the distal end, and including at least one lumen extending therethrough;
- a self-expanding frame positioned at the distal end of the shaft, the frame including a plurality of self-expanding sections disposed in the longitudinal direction, each of said self-expanding sections being connected to an adjacent self-expanding section via a separate joint, each of the plurality of self-expanding sections having an unbiased, expanded condition and a biased, collapsed condition, each of the plurality of self-expanding sections being foldable in the longitudinal direction and about the separate joint when in a biased, collapsed condition,
- wherein the at least one joint being oriented in a V-shape when the plurality of self-expanding sections are in the biased condition.
25. A system useful for treating an aneurysm in a blood vessel of a mammalian patient, the aneurysm having a neck, a wall, and a cavity, comprising:
- an elongated shaft having a proximal end, a distal end, a longitudinal direction defined between the proximal end and the distal end, and including at least one lumen extending therethrough;
- a self-expanding frame positioned at the distal end of the shaft, the frame including a plurality of self-expanding sections disposed in the longitudinal direction, each of said self-expanding sections being connected to an adjacent self-expanding section via a separate joint, each of the plurality of self-expanding sections having an unbiased, expanded condition and a biased, collapsed condition, each of the plurality of self-expanding sections being foldable in the longitudinal direction and about the separate joint when in a biased, collapsed condition,
- wherein the at least one joint collapses to a position parallel to an artery of the patient.
Type: Application
Filed: Jan 24, 2005
Publication Date: Jun 16, 2005
Applicant: University of Louisville Research Foundation (Louisville, KY)
Inventor: Hesham Abdel-Gawwad (Louisville, KY)
Application Number: 11/039,908