US20030195553A1 - System and method for retaining vaso-occlusive devices within an aneurysm - Google Patents

Abstract

The present invention is directed to systems and methods for occluding an aneurysm having an aneurysmal neck and an aneurysmal inner wall. Generally, a device in accordance with the present invention includes a mesh-like structure that is integrally composed of a shape-memory alloy such as NiTi. The device is deployed within the aneurysm through the aneurysmal neck. The device is configured to be in a deployed state and an undeployed state, and is configured to transition from the undeployed state to the deployed state by exposure to a higher temperature and/or by being unconstrained. The device may function to retain finer vaso-occlusive devices such as vaso-occlusive coils and/or embolic liquids. Furthermore, the device itself may function as a vaso-occlusive device.

Description

FIELD OF THE INVENTION
• The present invention relates generally to vaso-occlusion, and more particularly to systems and methods for retaining vaso-occlusive devices within an aneurysm.[0001]
BACKGROUND OF THE INVENTION
• Different implantable medical devices have been developed for treating a number of ailments associated with body lumens. In particular, occlusive devices are useful in filling vascular or other body spaces. Some body spaces, such as vascular aneurysms, are formed due to a weakening in the wall of an artery. Often these aneurysms are the site of internal bleeding and stroke. A variety of different embolic agents are known to be, at least arguably, suitable for treatment of these anomalies. These treatments are commonly known as “artificial vasoocclusion.”[0002]
• Over the past few years, advancements in the artificial occlusion of vessels and aneurysms have included the delivery and implantation of metal coils as vaso-occlusive devices. Implantable metal coils that are useful as artificial occlusion devices in vasculature lumens or aneurysms are herein referred to as “vaso-occlusive coils.” Vaso-occlusive coils are generally constructed of a wire, usually made of a metal or metal alloy that is wound to a helix. The vaso-occlusive coil assumes an irregular shape upon discharge of the device from the distal end of the catheter. A variety of vaso-occlusive coils are known. For instance, U.S. Pat. No. 4,994,069, issued to Ritchart et al., shows a flexible, preferably coiled, wire for use in small vessel vaso-occlusion. Unlike vaso-occlusive coils used prior to that time, Ritchart et al. teach a coil that is fairly soft and is delivered to the site using a pusher within a catheter lumen. Upon discharge from the delivery catheter, the coil may undertake any number of random or regular configurations used to fill the site.[0003]
• The coils may be used for small vessel sites, e.g., 0.5-6 mm in diameter. The coils themselves are described as being between 0.010 and 0.030 inches in diameter. The length of the coil wire is typically 15 to 20 times the diameter of the vessel to be occluded. The wire used to make up the coils may be, for instance, 0.002 to 0.006 inches in diameter. Tungsten, platinum, and gold threads or wires are said to be preferred. These coils have a variety of benefits including the fact that they are relatively permanent, they may be easily imaged radiographically, they may be located at a well defined vessel site, and they can be retrieved.[0004]
• In addition to the various types of space filling mechanisms and geometries of vaso-occlusive coils, other particularized features of coil designs, such as mechanisms for delivering vaso-occlusive coils through delivery catheters and implanting them in a desired occlusion site, have also been described. The examples of categories of vaso-occlusive coils based upon their delivery mechanisms include pushable coils, mechanically detachable coils, and electrolytically detachable coils.[0005]
• One example of the type of vaso-occlusive coil referred to above as the “pushable coil” is disclosed in Ritchart et al., discussed above. Pushable coils are commonly provided in a cartridge and are pushed or “plunged” from the cartridge into a delivery catheter lumen. A pusher advances the pushable coil through and out of the delivery catheter lumen and into the site for occlusion.[0006]
• Mechanically detachable vaso-occlusive coils are typically integrated with a pusher rod and are mechanically detached from the distal end of that pusher after exiting a delivery catheter. Examples of such mechanically detachable vaso-occlusive coils are found in U.S. Pat. No. 5,261,916 to Engelson or U.S. Pat. No. 5,250,071 to Palermo.[0007]
• Finally, examples of electrolytically detachable vaso-occlusive coils may be found in U.S. Pat. Nos. 5,122,136 and 5,354,295, each issued to Guglielmi et al. In these devices, the vaso-occlusive portion of the assembly is attached to a pusher via a small, electrolytically severable joint. The electrolytically severable joint is severed by the placement of an appropriate voltage on the core wire. The joint erodes in preference either to the vaso-occlusive coil itself or to the pusher core wire.[0008]
• As noted above, aneurysms present a particularly acute medical risk due to the dangers of potential rupture of the thin wall inherent in such aneurysms. Occlusion of aneurysms by use of vaso-occlusive coils without occluding the adjacent artery is a special challenge and is a desirable method of reducing such risk of rupture. These vaso-occlusive devices are typically placed in an aneurysm in a manner described in U.S. Pat. No. 4,739,768 issued to Engelson. In particular, a microcatheter is initially steered into or adjacent to the entrance of an aneurysm, typically aided by the use of a steerable guidewire. The wire is then withdrawn from the microcatheter lumen and replaced by the vaso-occlusive coil. The vaso-occlusive coil is advanced through and out of the microcatheter, desirably being completely delivered into the aneurysm.[0009]
• However, after, or perhaps during, delivery of the coil into the aneurysm, there is a specific risk that a portion of the coil might migrate out of the aneurysm entrance zone and into the feeding vessel. The presence of the coil in that feeding vessel may cause a highly undesirable occlusion there. Also, there is a quantifiable risk that the blood flow in the vessel and aneurysm may induce movement of the coil farther out of the aneurysm, resulting in a more developed embolus in the feeding vessel.[0010]
• One type of aneurysm, commonly known as a “wide neck aneurysm,” is known to present particular difficulty in the placement and retention of vaso-occlusive coils, because vaso-occlusive coils lacking substantial secondary shape strength may be difficult to maintain in position within an aneurysm no matter how skillfully they are placed. Wide neck aneurysms are herein referred to as aneurysms of vessel walls having a neck or “entrance zone” from the adjacent vessel, wherein the entrance zone has a diameter that either: (1) is at least 80% of the largest diameter of the aneurysm; or (2) is clinically observed to be too wide effectively to retain vaso-occlusive coils that are deployed using the techniques discussed above.[0011]
• One approach to occlude such an aneurysm is described in U.S. Pat. No. 6,168,622, which describes a vaso-occlusive device with a secondary shape having a bulbous body portion and an anchor. The bulbous body portion is deployed within the aneurysm while the anchor is set just outside of the aneurysm, covering the aneurysm's neck or entrance zone. The device is integrally formed from a tube—clamped at both ends—of braided Nickel-Titanium (NiTi) wires. The bulbous body functions to occlude the aneurysm, while the anchor covers the entrance zone. In some cases, it may still be desirable to deploy vaso-occlusive coils with such a device, but the bulbous body of the vaso-occlusive device does not provide much space within the aneurysm to allow for insertion and deployment of the coils.[0012]
• Accordingly, an improved system and method for occluding an aneurysm neck would be desirable.[0013]
SUMMARY OF INVENTION
• The present invention is directed to systems and methods for occluding an aneurysm having an aneurysmal neck and an aneurysmal inner wall. Generally, a device in accordance with the present invention includes a mesh-like structure that may be integrally composed of a shape-memory alloy such as NiTi. The device may be deployed within the aneurysm through the aneurysmal neck. The device may be configured to be in a deployed state and an undeployed state, and may be configured to transition from the undeployed state to the deployed state by exposure to a higher temperature and/or by being released from a compressive force. The device may function to retain finer vaso-occlusive devices such as vaso-occlusive coils and/or embolic liquids. Furthermore, the device itself may function as a vaso-occlusive device. The device may be delivered to the aneurysm by, e.g., a catheter.[0014]
• In accordance with a first aspect of the present invention, at least one of the proximal and distal ends of the mesh-like structure is configured to be inserted through the aneurysmal neck when in an undeployed state, and configured to flare open and expand against at least a portion of the aneurysmal inner wall when in a deployed state. Having a flared open end may advantageously allow the device to conform to the shape of the aneurysm.[0015]
• In accordance with another aspect of the present invention, the distal end of the mesh-like structure may be configured to be inserted through the aneurysmal neck when in an undeployed state and configured to expand into a retainer against at least a portion of the aneurysmal inner wall when in a deployed state. The proximal end may be configured to expand into an anchor just outside of the aneurysm to secure the mesh-like structure in position.[0016]
• Other objects and features of the present invention will become apparent from consideration of the following description taken in conjunction with the accompanying drawings.[0017]
BRIEF DESCRIPTION OF THE DRAWINGS
• In order to better appreciate how the above-recited and other advantages and objects of the present inventions are obtained, a more particular description of the present inventions briefly described above will be rendered by reference to specific embodiments thereof, which are illustrated in the accompanying drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:[0018]
• FIG. 1 is an illustration of a vaso-occlusive device constructed in accordance with a preferred embodiment of the present inventions, wherein the vaso-occlusive device is shown fully deployed within an aneurysm;[0019]
• FIGS.[0020]2(a) and2(b) illustrate one preferred method of manufacturing the vaso-occlusive device of FIG. 1 in accordance with the present inventions;
• FIG. 3 is an illustration of another vaso-occlusive device constructed in accordance with a preferred embodiment of the present inventions, wherein the vaso-occlusive device is shown fully deployed within an aneurysm;[0021]
• FIG. 4 illustrates one preferred method of manufacturing the vaso-occlusive device of FIG. 3 in accordance with the present inventions;[0022]
• FIG. 5 is an illustration of still another vaso-occlusive device constructed in accordance with a preferred embodiment of the present inventions, wherein the vaso-occlusive device is shown fully deployed within an aneurysm;[0023]
• FIG. 6 illustrates one preferred method of manufacturing the vaso-occlusive device of FIG. 5 in accordance with the present inventions;[0024]
• FIG. 7 is an illustration of still another vaso-occlusive device constructed in accordance with a preferred embodiment of the present inventions, wherein the vaso-occlusive device is shown fully deployed within an aneurysm;[0025]
• FIG. 8 illustrates one preferred method of manufacturing the vaso-occlusive device of FIG. 7 in accordance with the present inventions;[0026]
• FIGS.[0027]9(a)-(c) illustrate a preferred method of delivering and deploying the vaso-occlusive device of FIG. 1 into the aneurysm;
• FIGS.[0028]10(a)-(d) illustrate a preferred method of delivering and deploying the vaso-occlusive device of FIG. 7 into the aneurysm; and
• FIGS.[0029]11(a)-(c) illustrate a preferred method of delivering and deploying the vaso-occlusive device of FIG. 5 into the aneurysm.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
• Turning to FIG. 1, a vaso-[0030]occlusive element10 constructed in accordance with a preferred embodiment of the present invention is shown completely deployed within ananeurysm40 of ablood vessel60. Theaneurysm40 is shown with an oppositelydisposed neck70 anddome45. When deployed in its secondary shape, i.e., its deployed shape, the vaso-occlusive element10 generally includes a centraltubular element15 and proximal20 and distal30 ends that are flared open into “umbrella” shapes. As illustrated, the flared opened ends20/30 advantageously conform to the shape of theaneurysm40. The diameter of theproximal end20 of the vaso-occlusive element10 is larger than theneck70, and thus theproximal end20 may completely cover theneck70.
• As will be described in further detail below, the vaso-[0031]occlusive element10 is manufactured from a relatively dense braid. In this manner, theproximal end20 may densely cover theneck70 and function as a retainer. Thus, finer vaso-occlusive devices, such as vaso-occlusive coils or embolic liquids, may effectively be retained within theaneurysm40, or at the least, the likelihood of these devices migrating out from theaneurysm40 is minimized. Further, as can be appreciated by one of ordinary skill in the art, the relatively dense coverage of theproximal end20 allows the vaso-occlusive element10 itself to function as a vaso-occlusive device. The flared opendistal end30 is placed adjacent thedome45 of theaneurysm40 and allows theelement10 to safely conform to the shape of thedome45. This allows for thedistal end30 to function as an anchor and secure itself within theaneurysm40 without the need to conform to the entire shape of theaneurysm40. Thus, theelement10 may conform to a large variety of shapes and sizes ofaneurysms40 since theelement10 need only be secured within theaneurysm40 by conforming the flared opendistal end30 to thedome45.
• Turning to FIGS.[0032]2(a)-(b), one preferred method of manufacturing the vaso-occlusive device10 will now be described. First, a braided tubular element1 is constructed by braiding multiplefine wires2 together. The tubular element1 may also be formed of wires with varying diameters braided together. It may be desirable to use a larger number ofwires2 when forming the tubular element1, resulting in a relatively dense braid, which provides denser coverage within theaneurysm40. Optionally, the tubular element1 may be radiopaque. One method involves braiding a radiopaque fiber, such as platinum, Pt, or gold, Au, into the tubular element1. Another method involves plating or coating the tubular element1 with radiopaque material. Additionally, one or more radiopaque markers may be added to the tubular element1.
• Preferably, the[0033]wires2 are made from a shape memory alloy, which can be of any type, but preferably is a “one way” trainable shape memory alloy. A preferable shape memory alloy for forming the braided tubular element1 is Nickel-Titanium (NiTi)—e.g., 144 strands of 0.001″ NiTi wires. Shape memory alloys comprise a unique class of metal alloys that, once trained, are configured to “remember” a preselected shape, i.e., deployed shape, and can return to the preselected shape even if subsequently reshaped. To be trained to “remember” a first preselected shape, the shape memory alloy is molded and heated at or above a training, or austenite, temperature to place the shape memory alloy in an austenite phase. In the austenite phase, the shape memory alloy is formed in the first preselected shape and then, once formed, is permitted to cool to a martensite finish temperature, whereupon the shape memory alloy enters a martensite phase. The martensite finish temperature can be any temperature that is less than the training temperature. Upon entering the martensite phase, the shape memory alloy has been trained to “remember” the first preselected shape. While in the martensite phase, the alloy is in a soft state and is formed into a second preselected shape, e.g., an undeployed shape. The shape memory alloy in the martensite phase is configured to maintain the second preselected shape and, if subsequently reheated to an activation temperature, automatically returns to the first preselected shape. The activation temperature can comprise any temperature that is greater than the martensite finish temperature and generally approximately equals the training temperature. Once the first preselected shape has been recovered, the shape memory alloy is configured to maintain the first preselected shape irrespective of temperature. Generally, as can be appreciated by one of ordinary skill in the art, the training, martensite finishing, and activation temperatures for a shape memory alloy are adjustable, depending on the composition. For example, a slight extra amount of Nickel added to a NiTi alloy composition can change the training temperature from 0° C. to 100° C.
• Generally, the vaso-[0034]occlusive device10 described above is delivered to theaneurysm40 via a delivery catheter. The catheter delivers thedevice10 to theaneurysm40 and during the delivery, thedevice10 maintains an undeployed shape, e.g., the original tubular shape—methods of delivery will be described in more detail below. When thedevice10 is deployed, thedevice10 expands into its deployed shape, e.g., having flared open proximal and distal ends20/30, as shown in FIG. 1. Using a shape memory alloy to form thedevice10 provides for alternative methods of expanding thedevice10 into its deployed shape within theaneurysm40.
• One method involves configuring the[0035]device10 to self-expand within theaneurysm40 when deployed and exposed to the temperature of theaneurysm40. To configure thedevice10 to self-expand within theaneurysm40 when deployed and exposed to the temperature of theaneurysm40, the training and activation temperatures are adjusted to be at, or just below, the temperature of the aneurysm, which is approximately 37° Celsius—the human body temperature. The martensite temperature is adjusted to be at a lower temperature. With these temperatures set, thedevice10 is heated to, or above the training temperature—austenite phase—and shaped into its desired deployed shape, as described above. Then, the temperature is lowered to, or below, the martensite finish temperature—martensite phase—and shaped into its desired undeployed shape. Subsequently, thedevice10 is then placed inside the catheter as will be described below. The catheter can be constructed of a material that insulates thedevice10 from the outside environment and maintains the temperature of thedevice10 below the activation temperature. Thus, when the catheter is inserted into thelumen75 of theblood vessel60, thedevice10 does not expand into its deployed shape within the catheter. When thedevice10 is deployed into theaneurysm40 and exposed to the aneurysm temperature, the temperature of the device will rise at or above the activation temperature, and thedevice10 will expand into its deployed shape. Because the alloy is preferably “one way” trained, thedevice10 will then be configured to maintain the deployed shape irrespective of the temperature, as described above.
• An alternative method for expanding the[0036]device10 into its deployed shape within the aneurysm utilizes the super-elastic characteristic of shape memory alloys. After thedevice10 is configured to maintain its deployed shape irrespective of the temperature, as described above, thedevice10 is then maintained in its austenite phase. When thedevice10 is in its austenite phase, thedevice10 is super-elastic, i.e., thedevice10 may be deformed to a certain degree and still be able to return to its deployed shape. Thedevice10 is then placed within the catheter as will be described below, with the inner wall of the catheter compressing thedevice10 into its undeployed shape. When thedevice10 is released out of the catheter into theaneurysm40, theuncompressed device10 automatically expands into its deployed shape because of its super-elasticity.
• Further details on the structure and manufacturing process of braided tubular elements[0037]1 are disclosed in U.S. Pat. No. 6,168,622 issued to Mazzochhi, column 4, line 33 to column 6, line 24, and FIGS. 1A and 1B, of which are hereby incorporated by reference.
• Forming the deployed shape shown in FIG. 1 is achieved by using two[0038]mandrels85, each having acylindrical portion90 and an umbrella dome-shapedmold85, as illustrated in FIG. 2(a). To flare open the ends of the element1, each end is placed over thecylindrical portion90 of amandrel85 and compressed against thedome85, causing the ends to conform to the shape of thedome85 and flare open. The assembly of the twomandrels80 and the element1 is then heated at or above the training temperature to place the element1 in the austenite phase. The assembly is maintained at that temperature until the deployed shape has been formed.
• Then, the assembly is cooled to, or below, the martensite finishing temperature to place the element[0039]1 in the martensite phase. In the martensite phase, themandrels80 are removed from the element1, and the element1 is formed into an undeployed shape, e.g., the original tubular shape. This may be achieved by placing the element1 over acylindrical mandrel95 and compressing the flared ends to conform to the shape of thecylindrical mandrel95, as shown in FIG. 2b. Subsequently, the element1 may be reheated to the activation temperature, causing the element1 to return to the deployed shape. Once the deployed shape has been recovered, the element1 is configured to maintain the deployed shape irrespective of temperature.
• Turning to FIG. 3, another vaso-[0040]occlusive element110 constructed in accordance with a preferred embodiment of the present invention is shown completely deployed within theaneurysm40. As with the embodiment in FIG. 1, the vaso-occlusive element110, when deployed, generally includes a centraltubular element115 and a flareddistal end130. The vaso-occlusive element110 further includes aproximal end120 shaped as a flattened disk, which functions as a retainer. Theproximal end130 has a diameter larger than the diameter of theneck70, and thus completely covers the entrance zone150. The flatteneddisk130 has a layer of braided wires on both sides, and thus may advantageously provide two layers of braided wires to cover the entrance zone150 instead of one layer with the flared openproximal end20 shown in FIG. 1. As with the flared opendistal end30 of the vaso-occlusive element10, shown in FIG. 1, the flared opendistal end130 is placed adjacent thedome45 of theaneurysm40 and allows theelement110 to safely conform to the shape of thedome45.
• Turning to FIG. 4, one preferred method of manufacturing the vaso-[0041]occlusive device110 shown in FIG. 3 will now be described. As described above, a braided tubular element1 is first constructed. Forming the deployed shape is achieved by using one of themandrels85 shown in FIG. 2(a) and the cylindrical mandrel shown in FIG. 2(b), as illustrated in FIG. 4. As described above, to flare open the distal end of the element1, the distal end is placed over thecylindrical portion90 of themandrel85 with thedome80 and compressed against thedome80, causing the distal end to flare open. To form the flatteneddisk120, the proximal end is placed on thecylindrical mandrel95. The proximal tip and a portion of the centraltubular portion115 are then compressed together along the axis of thecylindrical mandrel95. This causes the proximal end to expand into a flatteneddisk120.
• The assembly of the two[0042]mandrels80/95 and the element1 is then heated at or above the training temperature to place the element1 in the austenite phase. The assembly is maintained at that temperature until the deployedshape110 has been formed. Then, the assembly is cooled to, or below, the martensite finishing temperature to place theelement110 in the martensite phase. In the martensite phase, themandrels80/95 are removed from theelement110, and theelement110 is formed into an undeployed shape, e.g., the original tubular shape1. This is achieved by placing theelement110 over thecylindrical mandrel95 and compressing the flared open end and flattened disk to conform to the shape of thecylindrical mandrel95, as shown in FIG. 2(b). If the element1 is configured to expand into its deployed shape upon exposure to a higher temperature, then the element1 may be placed within a delivery catheter in preparation for deployment, as described above. Alternatively, if theelement110 is configured to expand upon being released by a compressive force, then the element1 is reheated to, or above, the activation temperature, causing the element1 to return to the deployedshape110 and to be configured to maintain the deployedshape110 irrespective of temperature.
• Turning to FIG. 5, another vaso-[0043]occlusive element210 constructed in accordance with a preferred embodiment of the present invention is shown deployed within theaneurysm40. When in a deployed shape, theelement210 generally includes acentral portion215 and a distal end flared open into a “cup”shape230. Alternatively, the distal end may be flared open into a “cone” shape. The vaso-occlusive element210 further includes aproximal end220 shaped as a flattened disk. Theproximal end220 has a diameter larger than the diameter of theneck70. Only the flaredopen cup shape230 is deployed within theaneurysm40, whereas the flatteneddisk220 is deployed in thelumen75 of theblood vessel60 just outside of theaneurysm40, functioning as an anchor for theelement210. The cup shapeddistal end230 may retain fine vaso-occlusive devices such as vaso-occlusive coils and embolic liquids.
• Turning to FIG. 6, one preferred method of manufacturing the vaso-[0044]occlusive device310 shown in FIG. 5 will now be described. As described above, a braided tubular element1 is first constructed. Forming the deployed shape is achieved by using amandrel280 having a cup shapeddome285 facing outward coupled to acylindrical portion290 and acylindrical mandrel95. To form the cup shape, the distal end of the element1 is placed over thecylindrical portion290 of themandrel280 having thedome285 and compressed against thedome285, causing the distal end to flare open into a cup shape. To form the flattened disk, the proximal end is placed over thecylindrical mandrel95. The proximal tip and a portion of the centraltubular portion215 are then compressed together along the axis of thecylindrical mandrel95. This causes the proximal end to expand into a flatteneddisk220.
• The assembly of the two[0045]mandrels280/95 and the element1 is then heated at or above the training temperature to place the element1 in the austenite phase. The assembly is maintained at that temperature until the deployedshape210 has been formed. Then, the assembly is cooled to, or below, the martensite finishing temperature to place theelement210 in the martensite phase. In the martensite phase, themandrels280/95 are removed from theelement210, and theelement210 is formed into an undeployed shape, e.g., the original tubular shape1. This may be achieved by placing theelement210 over thecylindrical mandrel95 and compressing the flared open end and flattened disk to conform to the shape of thecylindrical mandrel95. If the element1 is configured to expand into its deployed shape upon exposure to a higher temperature, then the element1 may be placed within a delivery catheter in preparation for deployment, as described above. Alternatively, if theelement110 is configured to expand upon being released by a compressive force, then the element1 is reheated to, or above, the activation temperature, causing the element1 to return to the deployedshape110 and to be configured to maintain the deployedshape110 irrespective of temperature.
• Turning to FIG. 7, another vaso-[0046]occlusive element310 constructed in accordance with a preferred embodiment of the present invention is shown deployed within theaneurysm40. When in a deployed shape, theelement310 generally includes acentral portion315 and first and second flatteneddisks330/320 formed at the distal and proximal ends respectively. Only the first flatteneddisk330 at the distal end is deployed within theaneurysm40 whereas the second flatteneddisk320 is deployed within thelumen75 of theblood vessel60 just outside of theaneurysm40, functioning as an anchor to secure theelement310 in its position. The first flatteneddisk330 provides a wider coverage than thecup shape230 shown in FIG. 5. As with the other devices described above, thisdevice310 may also retain fine vaso-occlusive devices such as vaso-occlusive coils and embolic liquids. Thecentral portion315 may be conventionally sealed to prevent the fine vaso-occlusive devices from migrating out.
• Turning to FIG. 8, one preferred method of manufacturing the vaso-[0047]occlusive device310 shown in FIG. 7 will now be described. As described above, a braided tubular element1 is first constructed. Forming the deployed shape is achieved by using acylindrical mandrel95, as illustrated in FIG. 8. To form the first flatteneddisk330, the distal end is placed on thecylindrical mandrel95. The distal tip and a portion of the centraltubular portion315 are then compressed together along the axis of thecylindrical mandrel95. This causes the distal end to expand into a flatteneddisk330. To form the second flatteneddisk320, the proximal end is placed on thecylindrical mandrel95. The proximal tip and a portion of the centraltubular portion315 are then compressed together along the axis of thecylindrical mandrel95. This causes the proximal end to expand into a flatteneddisk320.
• The assembly of the[0048]mandrel95 and the element1 is then heated at or above the training temperature to place the element1 in the austenite phase. The assembly is maintained at that temperature until the deployedshape310 has been formed. Then, the assembly is cooled to, or below, the martensite finishing temperature to place theelement310 in the martensite phase. In the martensite phase, themandrel95 is removed from theelement310, and theelement310 is formed into an undeployed shape, e.g., the original tubular shape1. This may be achieved by placing theelement310 over thecylindrical mandrel95 and compressing the flatteneddisks320/330 to conform to the shape of thecylindrical mandrel95, as shown in FIG. 2(b). If the element1 is configured to expand into its deployed shape upon exposure to a higher temperature, then the element1 may be placed within a delivery catheter in preparation for deployment, as described above. Alternatively, if theelement110 is configured to expand upon being released by a compressive force, then the element1 is reheated to, or above, the activation temperature, causing the element1 to return to the deployedshape110 and to be configured to maintain the deployedshape110 irrespective of temperature.
• Generally, as mentioned above, the vaso-occlusive devices described above are delivered to an aneurysm within a blood vessel via a delivery catheter. Referring to FIGS.[0049]9(a)-(c), a method of deploying a vaso-occlusive device, and in this case the vaso-occlusive device10, to theaneurysm40 via adelivery catheter450 is illustrated. Turning first to FIG. 9(a), thecatheter450 is steered to just within theneck70 of theaneurysm40. At this point, the vaso-occlusive device10 is in its undeployed shape, and is coupled to aninner guidewire465 via an electrolytically severable joint455. The assembly of the vaso-occlusive device10 and theguidewire465 extends through the lumen of thedelivery catheter450 such that thedevice10 is positioned at the distal end of thecatheter450.
• Turning to FIG. 9([0050]b), theguidewire465 is then pushed toward the distal end of thecatheter450 causing the vaso-occlusive device10 to extend out of the distal end of thecatheter450, through theneck70, and into theaneurysm40. As the vaso-occlusive device10 is pushed out of thecatheter450, the portion of thedevice10 that is free from the constraints of thecatheter450 expands into its deployed shape, e.g., thedistal end30 flares open.
• As described above, the[0051]device10 may be configured to be in its martensite phase when delivered to theaneurysm40 and expand upon exposure to the temperature of theaneurysm40. Thus, when outside of thecatheter450, the temperature of thedevice10 rises and thedevice10 enters the austenite phase and expands into its deployed shape. Alternatively, thedevice10 may be configured to be super-elastic and automatically expand upon being-unconstrained by thecatheter450.
• Turning now to FIG. 9([0052]c), theguidewire465 continues to push thedevice10 out of the catheter until theproximal end20 of thedevice10 is deployed within theaneurysm40, expanding into its deployed shape, e.g., theproximal end20 flares open, as described above with thedistal end30. To release thedevice10 from the catheter450 a current is applied to theguidewire465, which causes the joint455 to sever from theproximal end20 of thecatheter10. Further discussion of the construction of, placement of, and other physical details of such electrolytically severable joints may be found in U.S. Pat. No. 5,122,136 to Guglielmi et al.; U.S. Pat. No. 5,354,295 to Guglielmi et al.; and U.S. Pat. No. 5,624,449 to Pham et al; and others. It should be noted that other types of vaso-occlusive devices, such as vaso-occlusive device110, can be delivered within theaneurysm40 in the manner described immediately above.
• Alternatively, referring to FIGS.[0053]10(a)-(c), a retractable sheath method of delivering a vaso-occlusive device, and in this case vaso-occlusive device310, to theaneurysm40 is illustrated. Turning to FIG. 10(a), thecatheter550 is steered to just within theneck70 of theaneurysm40. At this point, the vaso-occlusive device10 is in its undeployed shape, and is placed over aninner guidewire565 that extends through thelumen580 of thedelivery catheter565. Theouter wall555 of thecatheter565 that defines thelumen580 functions as a sheath. The assembly of the vaso-occlusive device310 and theguidewire565 extends through thelumen580 of thedelivery catheter450 such that thedevice10 is positioned at the distal end of thecatheter550.
• Turning to FIG. 10([0054]b), theguidewire565 is then pushed so that the distal end of vaso-occlusive device310 extends out of thecatheter550, through theneck70, and into theaneurysm40. Once unconstrained from thecatheter550, thedistal end330 of thedevice310 is allowed to expand into a first flattened disk adjacent the inner wall near theneck70 within theaneurysm40.
• As described above, the[0055]device310 may be configured to be in its martensite phase when delivered to theaneurysm40 and expand upon exposure to the temperature of theaneurysm40. Thus, when outside of thecatheter550, the temperature of thedevice310 rises and thedevice310 enters the austenite phase and expands into its deployed shape. Alternatively, thedevice310 may be configured to be super-elastic and expand upon being unconstrained by thecatheter550.
• Turning now to FIG. 10([0056]c), theguidewire565 continues to push thedevice310 out of the catheter until theproximal end320 of thedevice310 is deployed just outside of theaneurysm40, expanding into its deployed shape, e.g., a second flattened disk, as described above with thedistal end330. To release thedevice310 from thecatheter450, theguidewire565 is pulled out of thedevice310 and thecatheter550 is pulled out of theaneurysm40 andblood vessel60. The expanded310 device is secured in position within theaneurysm40 and will not be pulled out with thecatheter550. It should be noted that other types of vaso-occlusive devices, such as vaso-occlusive device310, can be delivered within theaneurysm40 in the manner described immediately above.
• As mentioned above, a vaso-occlusive device, such as vaso-[0057]occlusive device310, may function as a vaso-occlusive device and/or function as a vaso-occlusive device retainer. In this regard, after deployment, finer vaso-occlusive devices730 may be delivered into theaneurysm40 to be retained by thedevice310, as illustrated in FIG. 10(d). This is achieved by maintaining an axial lumen within a vaso-occlusive device to allow acatheter740 to fit through and insert materials such as vaso-occlusive coils730 or embolic liquids to further improve thrombogenecity within the aneurysm700.
• In another alternative, turning to FIGS.[0058]11(a)-(c), a push method of delivering a vaso-occlusive device, and in this case vaso-occlusive device210, to theaneurysm40 is illustrated. Turning to FIG. 11(a), thecatheter650 is steered to just within theneck70 of theaneurysm40. At this point, the vaso-occlusive device210 is in its undeployed shape, and is placed within thelumen680 of adelivery catheter650 near the distal tip of thecatheter650, which is steered toaneurysm40, just outside of theneck70. Aguidewire665, extending through the lumen655 is positioned such that it is capable of pushing thedevice210 out of thecatheter650 and into theaneurysm40, where thedevice230 may expand into its deployed shape, as described above.
• Turning to FIG. 11([0059]b), theguidewire665 is then pushed so that the distal end of vaso-occlusive device210 extends out of thecatheter650, through theneck70, and into theaneurysm40. Once unconstrained from thecatheter550, thedistal end230 of thedevice210 is allowed to expand into a flared open cup shape adjacent the inner wall near theneck70 within theaneurysm40.
• As described above, the[0060]device210 may be configured to be in its martensite phase when delivered to theaneurysm40 and expand upon exposure to the temperature of theaneurysm40. Thus, when outside of thecatheter650, the temperature of thedevice210 rises and thedevice210 enters the austenite phase and expands into its deployed shape. Alternatively, thedevice210 may be configured to be super-elastic and expand upon being unconstrained by thecatheter650.
• Turning now to FIG. 11([0061]c), theguidewire665 continues to push thedevice210 out of the catheter until theproximal end220 of thedevice210 is deployed just outside of theaneurysm40, expanding into its deployed shape, e.g., a flattened disk, as described above with thedistal end230. Thecatheter650 is then pulled out of theaneurysm40 andblood vessel60 to separate itself from thedevice210. The expanded210 device is secured in position within theaneurysm40 and will not be pulled out with thecatheter650. It should be noted that other types of vaso-occlusive devices, such as vaso-occlusive device210, can be delivered within theaneurysm40 in the manner described immediately above.
• While embodiments of the present invention have been shown and described, various modifications may be made without departing from the spirit and scope of the present invention, and all such modifications and equivalents are intended to be covered.[0062]

Claims (72)

What is claimed is:

1. A vaso-occlusive device for use in occluding an aneurysm having an aneurysmal neck and an aneurysmal inner wall, comprising:

a mesh-like structure comprising a proximal end and a distal end, at least one of the proximal and distal ends configured to be inserted through the aneurysmal neck when in an undeployed state, and configured to flare open and expand against at least a portion of the aneurysmal inner wall when in a deployed state.

2. The vaso-occlusive device ofclaim 1, wherein the mesh-like structure further comprises a central tubular element.

3. The vaso-occlusive device ofclaim 1, wherein the at least one proximal end and distal end comprises the distal end.

4. The vaso-occlusive device ofclaim 1, wherein the at least proximal end and distal end comprises the proximal end.

5. The vaso-occlusive device ofclaim 3, wherein the proximal end of the mesh-like structure is configured to be inserted through the aneurysmal neck when in the undeployed state, and configured to expand into a flattened disk against at least a portion of the aneurysmal inner wall when in the deployed state.

6. The vaso-occlusive device ofclaim 1, wherein the at least one of the proximal end and distal end is configured to expand by heat activation into the deployed state.

7. The vaso-occlusive device ofclaim 1, wherein the at least one of the proximal end and distal end is configured to expand into the deployed state upon release of a compressive force.

8. The vaso-occlusive device ofclaim 1, wherein the mesh-like structure is formed from a plurality of braided fine wires.

9. The vaso-occlusive device ofclaim 1, wherein the mesh-like structure is composed of a NiTi alloy.

10. The vaso-occlusive device ofclaim 9, wherein the fine wires have varying diameters.

11. The vaso-occlusive device ofclaim 9, wherein one or more of the fine wires are radiopaque.

12. The vaso-occlusive device ofclaim 1, wherein the mesh-like structure is coated with radiopaque material.

13. The vaso-occlusive device ofclaim 1, further comprising radiopaque markers coupled to the mesh-like structure.

14. A catheter assembly for occluding an aneurysm having an aneurysmal neck and an aneurysmal inner wall, comprising:

a delivery catheter having a distal end; and

a mesh-like structure detachably coupled to the distal end of the catheter, the mesh-like structure comprising a proximal end and a distal end, at least one of the proximal and distal ends configured to be inserted through the aneurysmal neck when in an undeployed state, and configured to flare open and expand against at least a portion of the aneurysmal inner wall when in a deployed state.

15. The catheter assembly ofclaim 14, wherein the mesh-like structure further comprises a central tubular element.

16. The catheter assembly ofclaim 14, wherein the at least one proximal end and distal end comprises the distal end.

17. The catheter assembly ofclaim 1, wherein the at least proximal end and distal end comprises the proximal end.

18. The catheter assembly ofclaim 16, wherein the proximal end of the mesh-like structure is configured to be inserted through the aneurysmal neck when in the undeployed state, and configured to expand into a flattened disk against at least a portion of the aneurysmal inner wall when in the deployed state.

19. The catheter assembly ofclaim 14, wherein the at least one of the proximal end and distal end is configured to expand by heat activation into the deployed state.

20. The catheter assembly ofclaim 14, wherein the at least one of the proximal end and distal end is configured to expand into the deployed state upon releasing a compressive force.

21. The catheter assembly ofclaim 14, wherein the mesh-like structure is formed from a plurality of braided fine wires.

22. The catheter assembly ofclaim 14, wherein the mesh-like structure is composed of a NiTi alloy.

23. The catheter assembly ofclaim 21, wherein the fine wires have varying diameters.

24. The catheter assembly ofclaim 21, wherein the fine wires are radiopaque.

25. The catheter assembly ofclaim 14, wherein the mesh-like structure is coated with radiopaque material.

26. The catheter assembly ofclaim 14, further comprising radiopaque markers coupled to the mesh-like structure.

27. The catheter assembly inclaim 14, wherein the mesh-like structure is capable of being delivered to the aneurysm using a method selected from a group consisting of an electrolytically severable method, a retractable sheath method, and a push method.

28. A method of occluding an aneurysm with a mesh-like structure, the aneurysm having an aneurysmal neck and an aneurysmal inner wall, comprising:

delivering the mesh-like structure to the aneurysm;

inserting an end of the mesh-like structure through the aneurysmal neck; and

flaring the end of the mesh-like structure open to expand against at least a portion of the aneurysmal inner wall.

29. The method ofclaim 28, wherein the end of the mesh-like structure comprises a distal end of the mesh-like structure.

30. The method ofclaim 28, wherein the end of the mesh-like structure comprises a proximal end of the mesh-like structure.

31. The method ofclaim 28, wherein the aneurysm comprises a dome, and the end of the mesh-like structure is expanded against the aneurysmal inner wall adjacent the dome.

32. The method ofclaim 28, further comprising:

inserting another end of the mesh-like structure through the aneurysmal neck; and

expanding the other end of the mesh-like structure into a flatten disk against at least a portion of the aneurysmal inner wall.

33. The method ofclaim 32, wherein the aneurysm comprises a dome, the end of the mesh-like structure is expanded against the aneurysmal inner wall adjacent the dome, and the other end of the mesh-like structure is expanded against the aneurysmal inner wall adjacent the aneurysmal neck.

34. The method ofclaim 28, wherein the mesh-like structure is heat activated to flare the end open.

35. The method ofclaim 28, wherein a compressive force is released from the mesh-like structure to flare the end open.

36. The method ofclaim 35, wherein the mesh-like structure is delivered to the aneurysm with a catheter.

37. The method ofclaim 36, further comprising releasing the mesh-like structure from the catheter using a method selected from a group consisting of an electrolytically severable method, a retractable sheath method, and a push method.

38. A vaso-occlusive device for use in occluding an aneurysm having an aneurysmal neck and an aneurysmal inner wall, the aneurysm residing in a vessel having a vessel inner wall, the device comprising:

a mesh-like structure comprising a retainer and an anchor, the retainer configured to be inserted through the aneurysmal neck when in an undeployed state, and configured to expand against a portion of the aneurysmal inner wall surrounding the aneurysmal neck when in a deployed state, wherein a portion of the aneurysmal inner wall is not covered by the mesh-like structure, the anchor configured to expand against a portion of the vessel inner wall adjacent the aneurysmal neck when in a deployed state.

39. The vaso-occlusive device ofclaim 38, wherein the mesh-like structure further comprises a central tubular element, and the retainer and anchor are formed at opposing ends of the central tubular element.

40. The vaso-occlusive device inclaim 38, wherein the retainer and anchor are shaped as flattened disks.

41. The vaso-occlusive device inclaim 38, wherein the retainer is shaped as a flared open cup and the anchor is shaped as a flattened disk.

42. The vaso-occlusive device ofclaim 38, wherein the retainer and anchor are configured to expand by heat activation into the deployed state.

43. The vaso-occlusive device ofclaim 38, wherein the retainer and anchor are s configured to expand into the deployed state when unconstrained.

44. The vaso-occlusive device ofclaim 38, wherein the mesh-like structure is formed from a plurality of braided fine wires.

45. The vaso-occlusive device ofclaim 38, wherein the mesh-like structure is composed of a NiTi alloy.

46. The vaso-occlusive device ofclaim 44, wherein the plurality of fine wires have varying diameters.

47. The vaso-occlusive device ofclaim 44, wherein the fine wires are radiopaque.

48. The vaso-occlusive device ofclaim 38, wherein the mesh-like structure is coated with radiopaque material.

49. The vaso-occlusive device ofclaim 38, further comprising radiopaque markers coupled to the mesh-like structure.

50. A catheter assembly for occluding an aneurysm having an aneurysmal neck and an aneurysmal inner wall, comprising:

a delivery catheter having a distal end; and

a mesh-like structure detachably coupled to the distal end of the catheter, the mesh-like structure comprising a retainer and an anchor, the retainer configured to be inserted through the aneurysmal neck when in an undeployed state, and configured to expand against a portion of the aneurysmal inner wall surrounding the aneurysmal neck when in a deployed state, wherein a portion of the aneurysmal inner wall is not covered by the mesh-like structure, the anchor configured to expand against a portion of the vessel inner wall adjacent the aneurysmal neck when in a deployed state.

51. The vaso-occlusive device ofclaim 50, wherein the mesh-like structure further comprises a central tubular element, and the retainer and anchor are formed at opposing ends of the central tubular element.

52. The vaso-occlusive device inclaim 50, wherein the retainer and anchor are shaped as flattened disks.

53. The vaso-occlusive device inclaim 50, wherein the retainer is shaped as a flared open cup and the anchor is shaped as a flattened disk.

54. The vaso-occlusive device ofclaim 50, wherein the retainer and anchor are configured to expand by heat activation into the deployed state.

55. The vaso-occlusive device ofclaim 50, wherein the retainer and anchor are configured to expand into the deployed state when unconstrained.

56. The vaso-occlusive device ofclaim 50, wherein the mesh-like structure is formed from a plurality of braided fine wires.

57. The vaso-occlusive device ofclaim 50, wherein the mesh-like structure is composed of a NiTi alloy.

58. The vaso-occlusive device ofclaim 56, wherein the plurality of fine wires have varying diameters.

59. The vaso-occlusive device ofclaim 56, wherein the fine wires are radiopaque.

60. The vaso-occlusive device ofclaim 50, wherein the mesh-like structure is coated with radiopaque material.

61. The vaso-occlusive device ofclaim 50, further comprising radiopaque markers coupled to the mesh-like structure.

62. A method of occluding an aneurysm with a mesh-like structure, the aneurysm having an aneurysmal neck and an aneurysmal inner wall, the aneurysm residing in a vessel having a vessel inner wall, comprising:

delivering the mesh-like structure to the aneurysm;

inserting a first end of the mesh-like structure through the aneurysmal neck;

expanding the first end of the mesh-like structure against a portion of the aneurysmal inner wall surrounding the aneurysmal neck, wherein a portion of the aneurysmal inner wall is not covered by the mesh-like structure; and

expanding a second end of the mesh-like structure against a portion of the vessel inner wall adjacent the aneurysmal neck to anchor the mesh-like structure.

63. The method ofclaim 62, wherein the mesh-like structure comprises a central tubular element between the first and second ends, and the method further comprises inserting the central tubular element within the aneurysmal neck.

64. The method ofclaim 62, wherein the first and second ends of the mesh-like structure are both expanded into flattened disks.

65. The method ofclaim 62, wherein the first end of the mesh-like structure is expanded into an open cup, and the second end of the mesh-like structure is expanded into a flattened disk.

66. The method ofclaim 62, wherein the mesh-like structure is heat activated to expand the first and second ends.

67. The method ofclaim 62, wherein a compressive force is released from the mesh-like structure to expand the first and second ends.

68. The method ofclaim 62, further comprising introducing a vaso-occlusive agent through the mesh-like structure and into the aneurysm, wherein the vaso-occlusive agent is retained within the aneurysm.

69. The method ofclaim 68, wherein the vaso-occlusive agent comprises one or more coils.

70. The method ofclaim 68, wherein the vaso-occlusive agent comprises an embolic agent.

71. The method ofclaim 62, wherein the mesh-like structure is delivered to the aneurysm with a catheter.

72. The method ofclaim 71, further comprising releasing the mesh-like structure from the catheter using a method selected from a group consisting of an electrolytically severable method, a retractable sheath method, and a push method.

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