Integrated collection basket and method

Abstract

A retrieval device, which, in conjunction with a catheter, removes an object from a subject's body, includes a tube having an expandable section at or adjacent to the distal end of the tube. The expandable section may be a basket. The basket may be self-expanding, or a user may manually control the basket's expansion. The basket's struts may rotate to facilitate engagement with the object to be removed from the subject's body (e.g., expansion into the object, grasping the object, etc.). The retrieval device may also be used to selectively control suction through the catheter or retrieval device. Methods for removing objects from a subject's body are also disclosed, as are methods for forming an expandable section of a medical device, such as a retrieval device.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS Priority is hereby claimed to U.S. Provisional Patent Application No. 63 / 399,196 (the "'196 Provisional Application"), entitled "UNIBODY RETRIEVAL BASKETS AND METHODS," filed August 18, 2022. The entire disclosure of the '196 Provisional Application is hereby incorporated herein.

[0002] The present disclosure generally relates to devices (e.g., medical devices, etc.) and device assemblies (e.g., medical device assemblies, etc.) for removing objects (e.g., stents, embolic devices, foreign bodies, lesions, embolisms, thrombi, etc.) from small spaces (e.g., locations within a subject's body (e.g., the subject's vasculature and / or other organs, including cavities, ventricles, and / or other spaces therein, etc.)). More specifically, the present disclosure relates to so-called "revascularization devices" and "retrieval devices" having an expandable basket that can be used with a catheter to remove objects from a subject's body. Even more specifically, the expandable basket of the medical devices of the present disclosure can include rotating struts to facilitate engagement with the object to be removed from the subject's body. Methods for removing objects from a subject's body are also disclosed, as are methods for manufacturing medical devices. [Background technology]

[0003] Various devices have been designed for removing objects from a subject's body. These devices are sometimes referred to as "revascularization devices" and "retrieval devices" or "retrievers." Many revascularization devices include a retrieval structure that is introduced into or adjacent to the object to be removed from the subject's body and then expanded to engage the object. With the object engaged with the retrieval structure, the revascularization device is preferably withdrawn from the subject's body, carrying the engaged object with it. Medtronic (SOLITAIRE® X), Stryker (TREVO®), and Cerenovus (EMBOTRAP® II) manufacture revascularization devices with expandable structures.

[0004] The retrieval structure of existing revascularization devices typically includes an expandable mesh element (e.g., a tube, etc.). Such an expandable mesh element can apply a radially outward force against an object to engage the object. A portion of the object can also be received by an opening in the expanded mesh element, which can further engage the object as the object is removed from the subject's body. The expandable mesh element and the object it engages can also be withdrawn proximally relative to the distal end of the catheter to capture the object between the expandable mesh element and the catheter, which can further facilitate removal of the object from the subject's body.

[0005] While existing retrieval devices are useful for removing some objects from a subject's body, their effectiveness is limited by their ability to engage the object. To improve the ability of such devices to remove objects from a subject's body, expandable mesh elements with increasingly complex geometries have been designed. Nevertheless, the effectiveness of existing revascularization devices continues to be limited by how the retrieval structure of such devices interacts with the object to be retrieved. Summary of the Invention [Means for solving the problem]

[0006] A retrieval device according to the present disclosure comprises, consists essentially of, or consists of a tube having an expandable section at or adjacent its distal end. The expandable section may comprise a basket. The basket may be self-expanding or the expansion of the basket may be manually controlled by a user.

[0007] The basket of the retrieval device may self-expand in any of a variety of suitable ways. For example, the basket may include a spring that contracts when radially constrained (e.g., when the basket is contained within the lumen of the catheter) and expands when released or freed from that radial constraint (e.g., by pushing the basket distally beyond the distal end of the catheter). Such a basket (and, optionally, its associated tubing) may be formed from, but is not limited to, stainless steel (e.g., 316L stainless steel, 316 stainless steel, etc.) or another suitable material (e.g., cobalt chromium (CoCr), nickel chromium (NiCr or nichrome) alloy (including, but not limited to, NiCr steel), etc.). As another example, the basket (and optionally its associated tubing) may comprise a material with shape memory that is in a contracted state under a first condition (e.g., room temperature, etc.) or a first set of conditions (e.g., room temperature, under radial constraint, etc.) and in an expanded state when exposed to a second condition (e.g., body temperature, etc.) or a second set of conditions (e.g., body temperature, released from radial constraint, etc.). Such a basket (and optionally its associated tubing) may be formed from, but is not limited to, a shape memory alloy (e.g., nitinol, etc.).

[0008] In embodiments in which a user can manually expand and, optionally, manually contract the basket, the retrieval device may include an expansion control wire extending through the tube and the basket, the distal end of the expansion control wire being attached to the retrieval device tube at a location distal to the basket (e.g., at the distal end of the tube, etc.). Expansion of the basket may be achieved by pulling the expansion control wire proximally. The basket may contract by pushing the expansion control wire distally against the retrieval device tube and / or due to resiliency of the basket (e.g., from one or more of the material from which the basket is formed, the configuration of the basket, etc.).

[0009] The basket may be defined by an arrangement of struts that rotate as the basket expands. More specifically, the struts may rotate from a circumferential orientation to a radial orientation as the basket expands. The outwardly (e.g., radially) oriented edges of the struts may have a configuration that allows the edges to cut into an object to be retrieved from the subject's body. The struts may rotate from their radial orientation toward or back to their circumferential orientation as the basket contracts.

[0010] In some embodiments, the retrieval device may include a hypotube. The basket of the retrieval device may include an expandable section of the hypotube. The expandable section may include a plurality of slits defining struts. The slits may be positioned to allow the expandable section of the hypotube to expand from its original outer diameter (OD) or its unexpanded OD to an expanded OD. The expanded OD of the occlusion device may be about two or even three times its original OD. The expandable section of the hypotube may also be shaped to ultimately allow the hypotube to expand to its predetermined final shape or its desired closed shape. The expandable section may be bare or covered by an expandable, elastic polymer film.

[0011] The hypotube material may allow the hypotube and the basket defined by the hypotube to be contracted into a shape that facilitates its insertion into and / or removal from a subject's body, but expand when the restraining force is removed. The hypotube may be made from, but is not limited to, a metal (e.g., nitinol, stainless steel, etc.) or a polymer (e.g., polyetheretherketone (PEEK)).

[0012] In some embodiments, rows of slits may be defined along the length of the expandable section of the hypotube. Each row of slits may be positioned along the generator of the expandable section (i.e., a line extending parallel to the axis of the expandable section from one end of the expandable section of the hypotube to the other end of the expandable section). Alternatively, each row of slits may be oriented somewhat spirally around the hypotube. The slits in each row may be offset from the slits in the adjacent row. Each slit at the end of the length of the expandable section (and the length of the hypotube) may overlap approximately halfway with one slit in the adjacent row (e.g., a complete slit at the end of the expandable section). Each slit at an intermediate position along the length of the expandable section (and the length of the hypotube) may overlap approximately halfway with each of two slits in the adjacent row. In other words, the slits in the expandable section may have a so-called "bricklay" arrangement, or they may be arranged like bricks in a so-called "running bond pattern."

[0013] The remaining solid portions of the expandable section are its struts. Thus, the slits define the struts of the expandable section. Each strut may extend along the length of the expandable section and, therefore, along the length of the hypotube. The struts may be aligned with the longitudinal axis of the expandable section and / or the longitudinal axis of the hypotube. Alternatively, the struts may be oriented helically around the hypotube. Each strut may have an arcuate cross-sectional shape taken transverse or perpendicular to the longitudinal axis of the basket and / or the longitudinal axis of the tube.

[0014] The slits in the expandable section of the hypotube can be arranged to allow the struts to torque and / or twist or rotate as the expandable section, or a portion thereof, expands. Such an arrangement can also allow the expanded portion of the expandable section to return to its unexpanded state when an appropriate restraining force is applied to the hypotube (e.g., if an external force constrains the hypotube within the tube, the diameter of the tube will decrease, causing the rotating struts to rotate back to a flat, unrotated position, etc.). Such an arrangement can allow the expandable section to have a smooth outer surface when in a constrained, or unexpanded, state, which can facilitate its movement through the catheter. As the expandable section expands and its struts rotate, the struts can engage adjacent objects, which can provide an additional mechanism for immobilizing the object prior to removal (i.e., object retrieval) from the subject's body. More specifically, as the struts rotate outward, the radial orientation of the struts and the exposed edges of the struts may allow the struts to extend (e.g., cut, etc.) into or otherwise mechanically engage the object. In some embodiments, further engagement of the object may be achieved by at least partially contracting the expandable section to rotate the struts toward their circumferential orientation.

[0015] The slits in the expandable section of the hypotube may be arranged to allow the struts of the expandable section to assume a desired final shape (e.g., a cylinder, a sphere, a symmetrical spiral, an asymmetrical spiral, or any other desired shape).

[0016] In another aspect, the retrieval device of the present disclosure may be part of a medical device assembly, or more specifically, a retrieval assembly, which may also include a catheter, which may facilitate delivery of the retrieval device to a specific location within a subject's body, such as a location from which an object is to be removed from the subject's body.

[0017] In addition to the retrieval device and catheter, the retrieval device assembly may include a slider. The optional slider may be associated with the proximal end of the catheter to facilitate movement of the retrieval device along the length of the catheter. Thus, the slider may also enable expansion of the retrieval device's basket by pushing the retrieval device distally and retraction of the basket by pulling the retrieval device proximally. Retraction of the basket may include pulling the proximal end of the expanded basket toward or proximally relative to the distal tip of the catheter, at least partially retracting the basket into the catheter lumen, or fully retracting the basket into the catheter lumen. Any of these actions may facilitate removal of the retrieval device and any object engaged with or carried by the retrieval device's basket from the subject's body.

[0018] In addition to the retrieval device and catheter, the retrieval device assembly may include a suction controller. The suction controller may include an enlargement element (e.g., a bulbous plug, etc.) associated with the distal tip of the catheter that may control the transmission of suction beyond the distal tip of the catheter. In some embodiments, the suction controller may include an enlargement element that remains distal to the basket. Such an enlargement element may be fixed in a predetermined position relative to the distal end of the retrieval device tube and thus distal to the basket of the retrieval device. A certain size of the enlargement element may allow the enlargement element to abut and seal against the distal tip of the catheter, preventing suction applied to the catheter from being transmitted and applied to the subject's body until the enlargement element of the suction controller is advanced distally beyond the distal tip of the tube. The enlargement element of the suction controller may be fixed to the distal end of the retrieval device tube. Thus, distal advancement of the retrieval device relative to the catheter may advance the enlargement element distally, away from the distal tip of the catheter. Alternatively, the suction controller may include a wire extending through the tubing of the retrieval device, with the dilation element of the suction controller secured to the distal end of the wire. Thus, distal advancement of the dilation element away from the distal tip of the catheter may be achieved by distally advancing the wire relative to the retrieval device and / or by distally advancing the retrieval device relative to the catheter. Such an embodiment of the suction controller thus allows suction to be transmitted beyond the distal tip of the catheter whenever the basket of the retrieval device is advanced distally (partially or fully) beyond the distal tip of the catheter.

[0019] In other embodiments, the suction controller may include a magnifying element that may enable control of suction beyond the distal end of the catheter, regardless of whether the basket is positioned within the lumen of the catheter or advanced distally beyond the distal tip of the catheter. Such a suction controller may include a magnifying element proximal to the basket. The magnifying element includes a lumen that receives a portion of the retrieval device tubing while limiting or preventing transmission of suction between the inner surface of the lumen and the outer surface of the portion of the retrieval device tubing positioned within the lumen. Such an arrangement may allow a user to selectively apply suction to the location and / or object to be retrieved upon deployment of the basket from the distal end of the catheter.

[0020] In another aspect, the present disclosure includes methods for retrieving an object from a subject's body, including, but not limited to, revascularization methods. Such methods include advancing a basket of a retrieval device toward a location within the subject's body from which the object is to be removed. The basket of the retrieval device can be positioned adjacent to the object (e.g., into or through the object, next to the object, etc.). The basket can expand when the basket is positioned adjacent to the object or after the basket is positioned adjacent to the object. As the basket expands to engage the object, the struts of the basket rotate outward from a circumferential orientation to a radial orientation to facilitate further engagement with the object. In some embodiments, the expanded basket can at least partially contract, e.g., rotate at least partially toward the circumferential orientation of the struts to allow the struts to further engage the object by gripping the object. Once the basket engages the object, the basket and the retrieval device of which the basket is a part can be removed from the subject's body by pulling the object with the retrieval device. Engagement with and removal of the object from the body may be facilitated by suction applied through a catheter used with the retrieval device.

[0021] A method for defining a medical device (e.g., a retrieval device or revascularization device, etc.) (e.g., from a shape memory alloy (e.g., Nitinol, etc.) or the like) may include providing a tube (e.g., formed from a shape memory alloy, etc.), defining an expandable section of the medical device (e.g., a basket, etc.) from the tube, defining a treatment access section from the tube, and imparting an expanded shape to the expandable section.

[0022] The expandable section and treatment access section may be defined by cutting (e.g., laser cutting, etc.) the distal portion of the tube. The treatment access section may include an elongated notch or slit substantially aligned around the circumference of the tube, continuous with the end (e.g., the proximal end, etc.) of the expandable section, and extending from the end of the expandable section without extending to the end of the tube. Thus, the treatment access section may comprise a temporarily expandable extension of the expandable section. The treatment access section may be open at a location adjacent the end of the basket to eliminate the need to cut the expandable section to facilitate further processing, thus enabling the formation of an expandable section with two constrained or reduced-diameter ends. More specifically, the treatment access section may be open to allow a forming mandrel to be introduced into the tube and positioned within the portion of the tube that will define the expandable section.

[0023] With the forming mandrel in place, a collar may be positioned over the treatment access section to close it off and reduce the outer diameter of the treatment access section (e.g., so that the outer diameter of the treatment access section is substantially the same as the outer diameter of the uncut portion of the tubing, etc.). The tubing, forming mandrel, and collar may then be treated (e.g., annealed, heat set, etc.) as known in the art to define the expanded shape of the expandable section and ensure that the treatment access section of the tubing remains closed throughout use of the medical device.

[0024] Once processing is complete, the forming mandrel can be pushed from the expandable section into the treatment access section and removed through a slit in the treatment access section. Once the forming mandrel is removed, the treatment access section springs back to its closed state, defined by the collar during processing. Such methods can also be used to manufacture other types of medical devices having an expandable section. Forming and closing the treatment access section at an intermediate location in the tube (a location that does not extend to the end of the tube) eliminates the need to re-constrain the end of the expandable section with a collar, sleeve, weld, or bump, thus eliminating the possibility of such constraint failure.

[0025] Other aspects of the disclosed subject matter, as well as features and advantages of various aspects of the disclosed subject matter, will become apparent to those of ordinary skill in the art through consideration of the following description, the accompanying drawings, and the appended claims.

[0026] The drawings are as follows: [Brief explanation of the drawings]

[0027] [Figure 1]FIG. 1 is a perspective view of a medical device assembly including a catheter, one embodiment of a retrieval device, and an optional slider, showing an expandable section of the retrieval device, which can be deployed from the distal tip of the catheter and self-expand. [Figure 2] 2 is a side view of the distal end of the embodiment of the medical device assembly shown in FIG. 1 with the expandable section of the retrieval device advanced only partially distally beyond the distal tip of the catheter. [Figure 3] A side view of the distal end of the embodiment of the medical device assembly shown in Figure 2 in a partially expanded state, with the expandable section of the retrieval device advanced further distally, although still only partially, beyond the distal tip of the catheter. [Figure 4] 2 is a side view of the distal end of the embodiment of the medical device assembly shown in FIG. 1 with the expandable section of the retrieval device advanced fully distally beyond the distal tip of the catheter. [Figure 5] 2 is a side view of the distal end of the embodiment of the medical device assembly shown in FIG. 1 in a fully expanded state in which the expandable section of the retrieval device has been advanced distally beyond the distal tip of the catheter. [Figure 6] 1 is a design drawing showing the features and dimensions of a particular embodiment of a retrieval device. [Figure 7] 1A-1C depict an embodiment of some of the methods of manufacturing the expandable section of a medical device. [Figure 8] 1A-1C depict an embodiment of some of the methods of manufacturing the expandable section of a medical device. [Figure 9] 1A-1C depict an embodiment of some of the methods of manufacturing the expandable section of a medical device. [Figure 10] 1A-1C depict an embodiment of some of the methods of manufacturing the expandable section of a medical device. [Figure 11]11 depicts one embodiment of a medical device manufactured using the method depicted by FIGS. 7-10. FIG. [Figure 12] FIG. 10 is a partial perspective view of another embodiment of a medical assembly including a catheter and an embodiment of a retrieval device having an expandable section that is manually expandable and optionally contractible. [Figure 13] FIG. 10 shows a distal portion of one embodiment of a retrieval device including a suction controller proximal to the expandable section of the retrieval device. [Figure 14] Figures 14-17 illustrate how the suction controller of the embodiment of the retrieval device shown in Figure 13 functions as part of a medical device assembly, and Figures 14-16 show how the suction controller limits or prevents the transmission of suction applied to the lumen of the catheter beyond the distal end of the catheter when the expandable section of the retrieval device is advanced distally beyond the distal end of the catheter. [Figure 15] As stated above. [Figure 16] As stated above. [Figure 17] FIG. 17 is a diagram showing how the suction controller can be advanced distally beyond the distal end of the catheter and / or pulled proximally toward the distal end of the catheter to allow the user to control the amount of suction applied distally beyond the distal end of the catheter (e.g., to an object being retrieved, etc.). [Figure 18] FIG. 10 shows a distal portion of one embodiment of a retrieval device including a suction controller distal to the expandable section of the retrieval device. [Figure 19] Figures 19-22 illustrate how the suction controller of the embodiment of the retrieval device shown in Figure 18 functions as part of a medical device assembly, and more specifically, how suction applied to the lumen of the catheter is transmitted beyond the distal end of the catheter as soon as the retrieval device, and therefore the suction controller, is advanced distally relative to the catheter. [Figure 20] As stated above. [Figure 21] As stated above. [Figure 22] As stated above. [Figure 23] 23-25 ​​illustrate various embodiments of expandable sections or baskets of retrieval devices according to the present disclosure. [Figure 24] As stated above. [Figure 25] As stated above. DETAILED DESCRIPTION OF THE INVENTION

[0028] 1, there is depicted one embodiment of a medical device assembly 10. The medical device assembly 10 includes a catheter 20 and an embodiment of a retrieval device 40. The medical device assembly 10 may also include a slider 70.

[0029] Catheter 20 may include any catheter suitable for use in a tissue from which an object is to be retrieved (e.g., neurovascular, cardiovascular, etc.). More specifically, catheter 20 may carry retrieval device 40 to a desired location within a subject's body or may provide a pathway for advancement of retrieval device 40 to a desired location within a subject's body. Catheter 20 may enable operation of retrieval device 40 as well as facilitate engagement with and removal of the object from the subject's body.

[0030] The catheter 20 includes a proximal end 22 and a distal end 28. A distal tip 29 may be provided at the distal end 28 of the catheter 20. A lumen 24 extends through the catheter 20 along the length thereof and opens at the proximal end 22 and the distal end 28 to establish communication between the proximal end 22 and the distal end 28.

[0031] The dimensions of catheter 20 may be sufficient to aspirate a variety of objects from a subject's body, including, but not limited to, emboli, thrombi, tissue, lesions, embolic devices, stents, etc. Catheter 20 may have an OD of about 0.020 inches (about 0.5 mm) to about 0.5 inches (about 12.7 mm) and a lumen 24 with an inner diameter (ID) of about 0.015 inches (about 0.4 mm) to about 0.450 inches (about 11.4 mm).

[0032] Retrieval device 40 is an elongated medical device. Retrieval device 40 may include a tube 41 having a proximal end 42, a distal end 48, a distal portion 46 adjacent distal end 48, and an intermediate portion 44 between proximal end 42 and distal portion 46. An expandable section 50, which includes a basket of retrieval device 40, is defined in distal portion 44 of tube 41. Because retrieval device 40, including its expandable section 50, may be defined from a single tube, retrieval device 40 may be referred to as having a unitary or “unibody” structure.

[0033] The tube 41 may be formed from any of a variety of suitable materials or combinations of materials. In some embodiments, the tube 41 may include a hypotube, which may be formed from a substantially rigid material such as a metal. Examples of suitable metals include, but are not limited to, shape memory alloys (e.g., nitinol, etc.), cobalt chromium (CoCr), nickel chromium (NiCr or nichrome) alloys (including, but not limited to, NiCr steel), stainless steel (e.g., 316L stainless steel, 316 stainless steel, etc.), etc. Alternatively, the body 12 may be formed from a polymer. A suitable polymer may have a sufficient hardness (e.g., at least Shore D35, Shore D35 to Shore D55, Shore D35 to Shore D72, etc.). Examples of suitable polymers include, but are not limited to, polyetheretherketone (PEEK), polyimide, nylon, polyether block amide (PEBA, such as the brand name PEBAX®), and extruded plastic (provided the extruded plastic has a wall thickness that does not exceed the width of those struts 56, as described below).

[0034] Tube 41 may have an ID that accommodates a guidewire (e.g., a guidewire having an OD of about 0.010 inches (about 0.25 mm) to about 0.038 inches (about 0.97 mm). Tube 41 may have an OD of about 0.015 inches (about 0.4 mm) to about 0.450 inches (about 11.4 mm) and an ID of about 0.010 inches (about 0.25 mm) to about 0.440 inches (about 11.2 mm), i.e., an OD and ID in any of the ranges specified above.

[0035] Expandable section 50 of retrieval device 40 can expand outward (e.g., radially outward, etc.) from an unexpanded state, as shown in FIGS. 2 and 6, to an expanded state and to a final shape, as shown in FIGS. 1 and 5. For example, in embodiments in which tube 41 is formed from stainless steel or a polymer, expandable section 50 can expand to its final shape when a restraining force is removed from expandable section 50. As another example, in embodiments in which tube 41 is formed from a shape memory material, such as a shape memory alloy, expandable section 50 can expand to its final shape when exposed to appropriate conditions (e.g., body temperature, etc.). In yet another example, expandable section 50 can be manually expanded.

[0036] 2-5 progressively illustrate the distal advancement of the expandable section 50 of the retrieval element 40 through and beyond the distal end 28 of the catheter 20, and the expansion of the expandable section 50 upon removal from the constraints of the catheter 20. In FIG. 2, the distal end 48 of the tube 41 of the retrieval device 40 and a distal portion of the expandable section 50 emerge from the distal end 28 of the catheter 20. As distal advancement continues, more of the expandable section 50 emerges, as shown in FIG. 3. In embodiments in which the expandable section 50 is self-expanding, the expandable section 50 may expand as it exits the distal end 28 of the catheter 20, as also shown in FIG. 3. As FIG. 4 illustrates, the expandable section 50 may fully expand once it is advanced distally beyond the distal end 28 of the catheter 20. As illustrated by FIG. 5, the expandable section 50 can be advanced further distally beyond the distal end 28 of the catheter 20 .

[0037] Referring again to FIG. 1 , slider 70 may be associated with proximal end 22 of catheter 20 and proximal end 42 of tube 41 of retrieval device 40. Slider 70 facilitates movement of retrieval device 40 relative to catheter 20 and may also facilitate movement of catheter 20 relative to retrieval device 40. Slider 70 may allow retrieval device 40 to be advanced distally and / or retracted proximally or pulled relative to catheter 20. More specifically, slider 70 may enable distal advancement of tube 41 of retrieval device 40, which may allow distal end 48 of tube 41 and expandable section 50 of retrieval device 40 to advance distally through and beyond distal end 28 of catheter 20. Such distal advancement may occur when a user operates slider 70. The slider 70 may also retract or pull the tube 41 proximally through the lumen 22 of the catheter 20 to at least partially retract the expandable section 50, for example, to further engage an object to be removed from the subject's body. Such proximal retraction may occur when a user operates the slider 70, or such proximal retraction may be automatic (e.g., the slider 70 may include a spring or the like arranged to pull the tube 41 proximally).

[0038] The slider 70 may be fixed in position relative to the proximal end 22 of the catheter 20 while engaging the proximal end 42 of the tube 41 to facilitate movement of the retrieval device 40 along the length of the catheter 20. In some embodiments, the slider 70 may also be capable of moving the catheter 20 on the retrieval device 40 (e.g., by pulling the catheter 20 proximally, etc.).

[0039] 6, a particular embodiment of the expandable section 50 of the retrieval device 40 is depicted. The expandable section 50 may be defined by a series of slits 52 54a, 54b, 54c, etc. that extend at least partially through the wall of the tube 41. In some embodiments, each slit 52 may extend completely through the wall of the tube 41 from its outer surface to its inner surface. In other embodiments, each slit 52 may extend only partially through the wall of the tube 41 (e.g., from the outer surface of the wall toward the inner surface of the wall). The extent to which each slit 52 extends through the wall of the tube 41 may depend, at least in part, on the material from which the tube 41 is formed.

[0040] The slits 52 may have the same length as one another (with the exception of some slits 52 located at the ends of the expandable section 50). Adjacent slits 52 in a series 52a, 52b, 52c, etc. are separated by solid, uncut regions of the tube 41. These solid regions may be referred to as joinders 58 or junctions.

[0041] Each series 54a, 54b, 54c, etc. may be defined by linearly aligned slits 52. The slits 52 and each series 54a, 54b, 54c, etc. may extend longitudinally along the tube 41, with each series 54a, 54b, 54c, etc. positioned along a generator of the expandable section 50 (i.e., a line extending parallel to the longitudinal axis of the expandable section 50 from one end of the expandable section 50 to the other end of the expandable section 50). Such an orientation may be referred to as a "linear" orientation. Alternatively, each series 54a, 54b, 54c, etc. may be oriented helically around the tube 41.

[0042] The slits 52 in each series 54b, 54c, 54d, etc. may be offset relative to the slits 52 in each adjacent series 54a, 54b, 54c, 54d, 54e, etc. Each slit 52 in a series 54a, 54b, 54c, etc. may overlap with approximately half of one (if the slits 52 are located at or near the ends of the expandable section 30) or two (if the slits 52 are located midway along the length of the expandable section 50) circumferentially adjacent slits 52 in each adjacent series 54a, 54b, 54c, etc. Staggering the slits 52 around the circumference of the expandable section 50 can give the expandable section 50 a so-called "brickwork" appearance, with the solid portions of the tube 41 between the slits 52 arranged in a so-called "running bond pattern."

[0043] Circumferentially adjacent series 54a, 54b, 54c, etc. of slits 52 may be spaced equidistantly around the circumference of tube 41. Expandable section 50 may include an even number of series 54a, 54b, 54c, etc. of slits 52. In embodiments in which an even number of circumferentially adjacent series 54a, 54b, 54c, etc. of slits 52 are spaced equidistantly around the circumference of tube 41, each slit 52 in expandable section 50 may be staggered with respect to its circumferentially adjacent slits 52. Alternatively, the distance between slits 52 in one circumferentially adjacent series 54a may be different from the distance between slits 52 in another circumferentially adjacent series 54c. Thus, the number of slits 52 in one circumferentially adjacent series 54a may be different from the number of slits 52 in another circumferentially adjacent series 54c.

[0044] The solid portion of tube 41 located between each pair 54a and 54b, 54b and 54c, 54c and 54d, etc. of adjacent series of slits 52 comprises a strut 56 of expandable section 50. More specifically, each strut 56 may comprise the solid portion of tube 41 between adjacent series 54a and 54b, 54b and 54c, 54c and 54d, etc. of slits 52. In other words, each slit 52 comprises a gap between circumferentially adjacent pairs of struts 56. In embodiments in which series 54a, 54b, 54c, etc. are oriented along the longitudinal axis of tube 41, struts 56 may also be oriented along the longitudinal axis of tube 41. In embodiments in which series 54a, 54b, 54c, etc. are oriented helically around tube 41, struts 56 may also be oriented helically or as a single helix around tube 41.

[0045] Staggering the slits 52 may allow the expandable section 50 to expand. As the expandable section 50 expands, the struts 56 may rotate. When the expandable section 50 is expanded, the struts 56 may rotate up to 90 degrees. Such rotation may occur in embodiments where each ring of circumferentially aligned struts 56 around the expandable section 50 includes an even number of struts 56. As the struts 56 rotate, their edges protrude outward (i.e., somewhat radially, substantially radially, radially, etc.) from the expandable section 50.

[0046] In certain embodiments, such an expandable section 50 may expand to an OD of about 15 mm, with the slits 52 opening to spaced adjacent struts 56 spaced about 2 mm to 8 mm apart.

[0047] 6, the retrieval device 40 may also include a processing access section 60. The processing access section 60 is adjacent to and contiguous with the end of the expandable section 50. As depicted, the processing access section 60 may be located proximal to the expandable section 50.

[0048] Treatment access section 60 may be defined from tube 41 in the same manner as expandable section 50. Also, the definition of treatment access section 60 may occur together with (e.g., simultaneously with, immediately before, immediately after, etc.) the definition of expandable section 50.

[0049] The processing access section 60 may include elongated access slits 62, which may be continuous with at least some of the slits 52 at the end of the expandable section 50. The access slits 62 may be substantially aligned around the circumference of the tube 41 to define access struts 66 therefrom. The number and length of the access slits 62 and access struts 66 may allow the processing access section 60 to be opened to facilitate processing of the tube 41 during manufacture of the retrieval device 40 from the tube 41. More specifically, a pair of adjacent access struts 66 on either side of the access slit 62 may be pulled away from each other to define an opening in the processing access section 60 of the tube 41.

[0050] 7-10 , the treatment access section 60 may facilitate the introduction of a forming mandrel 80 into the expandable section 50 to define the expanded shape of the expandable section 50 (e.g., the shape that the expandable section 50 would assume if no restraining forces prevented the radial expansion of the expandable section 50, the shape that an expandable section 50 formed from a shape-memory material would assume when exposed to appropriate conditions, etc.). More specifically, the length of the slit 62 in the treatment access section 60 may allow the slit 62 to be opened large enough to allow the forming mandrel 80 to pass therethrough. In such embodiments, the treatment access section 60 may also facilitate the removal of the forming mandrel 80 from the expandable section 50 once the expanded shape of the expandable section 50 has been defined.

[0051] Forming mandrel 80 has a shape that defines the expanded shape of expandable section 50. Forming mandrel 80 also includes a positioner 81 insertable into tube 41 to determine the position of forming mandrel 80, and thus the expanded shape of expandable section 50, relative to the longitudinal axis of tube 41. Although forming mandrel 80 is depicted as spherical with positioner 81 locating the center of mandrel 80 along the longitudinal axis of tube 41, forming mandrel 80 may have other shapes. For example, mandrel 80 may be elliptical, cylindrical, or any other suitable shape. Positioner 81 may also be positioned within expandable section 50 at other locations relative to the longitudinal axis of tube 41, such as an offset or off-center position.

[0052] 7 shows the process access section 60 in an open configuration, with the pair of access slits 66 moved away from each other to expand the slit 62 (FIG. 6) therebetween into an opening 62′ that accommodates a forming mandrel 80. As shown, the introduction of the forming mandrel 80 into the process access section 60 causes the process access section 60 to expand.

[0053] As shown in FIG. 8, forming mandrel 80 is then forced distally into expandable section 50, which causes expandable section 50 to expand.

[0054] FIG. 9 shows the placement of a distal restraint 82 (e.g., a collar, etc.) distal to the expandable section 50 to distally secure the forming mandrel 80 in place along the length of the expandable section 50 and tube 41.

[0055] 10 illustrates the advancement of a proximal restraint 84 (e.g., a collar, etc.) into position over the treatment access section 60 of the tube 41. The proximal restraint 84 further secures the forming mandrel 80 in position along the length of the expandable section 50 and the tube 41.

[0056] With forming mandrel 80 in place within expandable section 50, tube 41 may be annealed as known in the art to define the expanded shape of the expandable section, or the shape that expandable section 50 will assume when exposed to appropriate conditions (e.g., body temperature, etc.). Once the annealing process is complete, distal restraint 82 and proximal restraint 84 may be removed, and forming mandrel 80 may be pushed from expandable section 50 into treatment access section 60 (see FIG. 8) and removed through opening 62′ defined by slit 62 in treatment access section 60. Once forming mandrel 80 is removed, treatment access section 60 will spring back to its closed state, as seen in FIG. 11.

[0057] 12, a medical device assembly 10' is depicted having a retrieval device 40' that includes a manually expandable embodiment of an expandable section 50'. The expandable section 50' is contracted when no force is applied to the expandable section 50' but can radially expand when its length is shortened. The retrieval device 40' can include an expansion control wire 45' that extends through the tube 41' and expandable section 50' of the retrieval device 40', with the distal end (not shown) of the expansion control wire 45' attached to the tube 41' (e.g., to the distal end of the tube 41') at a location distal to the expandable section 50'. Expansion of the expandable section 50' can be achieved by pulling the expansion control wire 45' proximally. The expandable section 40' may contract due to pushing the expansion control wire 45' distally against the tube 41' and / or due to the elasticity of the expandable section 50' (e.g., from one or more of the material from which the expandable section 50' is formed, the configuration of the expandable section 50', etc.).

[0058] Referring again to FIG. 1 , during use, the distal end of the catheter 20 can be advanced to a desired location within a subject's body, such as a location where an object is to be removed from the subject's body. Such placement can include placing the distal end 28 of the catheter 20 through or adjacent to the object until the expandable section 50 (in an unexpanded state within the lumen 24 of the catheter 20) is located within or adjacent to the object to be removed. The distal end 28 of the catheter 20 can then be retracted to expose the expandable section 50 and allow it to expand onto or into the object to be removed. Alternatively, such placement can include placing the distal end 28 of the catheter at a location near the object to be removed. The retrieval device 40 and its expandable section 50 can then be advanced from the distal end 28 of the catheter 20 to a location within or adjacent to the object to be retrieved. As the expandable section 50 expands, the expandable section 50 engages the object to be retrieved.

[0059] As the expandable section 50 expands into or onto the object to be retrieved, its struts 56 may rotate outward, orienting the edges of the struts 56 radially. Such orientation reduces the profile of the struts 56, which may allow the struts 56 to slice and / or cut through some objects (e.g., fresh thrombus, semi-fresh thrombus, older thrombus, etc.).

[0060] Once the expandable section 50 engages the object to be removed, the expandable section 50 can be pulled against and / or partially into the distal end 28 of the catheter 20, thereby trapping the object between the retrieval device 40 and the catheter 20. Retraction of the expandable section 50 also at least partially contracts the expandable section 50, which can rotate its struts 56 toward or about their circumferential orientation. Such rotation can grasp or retain some objects (e.g., thrombus, embolus, lesion, stone, foreign body, etc.).

[0061] While expandable section 50 is engaged with the object, the object may be retracted from the subject's body. Such removal may occur by aspirating the object through tube 41 of retrieval device 40 and / or lumen 24 of catheter 20, by pulling retrieval device 40 proximally through lumen 24 of catheter 20, or by removing the entire medical device assembly 10 from the subject's body.

[0062] 13-22, in some embodiments, the suction or application of suction beyond the distal end 28 of the catheter 20 can be controlled by movement of the retrieval device 40 relative to the catheter 20.

[0063] As depicted by FIGS. 13-17 , the retrieval device 40″ can include a suction controller 90″. The suction controller 90″ can include an enlargement element that can enable control of suction beyond the distal end of the catheter 20, regardless of whether the expandable section 50″ is positioned within the lumen 24 of the catheter 20 or advanced distally beyond the distal end 28 of the catheter 20. Such a suction controller 90″ can be located proximal to the expandable section 50″. The expandable section 90″ includes a lumen (not shown) that receives a portion of the tube 41″ of the retrieval device 40″ while limiting or preventing communication of suction between the inner surface of the lumen 24 and the outer surface of the portion of the tube 41″ of the retrieval device 40″ positioned within the lumen 24. Such an arrangement may limit the transmission of suction beyond the distal end 28 of the catheter 20 until the expandable section 50'' is fully deployed, as indicated by the small arrows and x in Figures 14 and 15, and then, by advancing the retrieval device 40'' distally or retracting the catheter 20 proximally, allow the user to selectively apply suction to the location and / or to the object to be retrieved once the expandable section 50'' is deployed from the distal end 28 of the catheter 20, as indicated by the small arrows and x in Figure 16 (limited suction) and the large arrow in Figure 17 (full suction).

[0064] 19-22 illustrate an embodiment of a retrieval device 40'" having a suction controller 90'" distal to the expandable section 50'". Such a suction controller 90'" may comprise an enlarged element secured in a predetermined position relative to the distal end 48'" of the tube 41'" of the retrieval device 40'", and thus distal to the expandable section 50'" of the retrieval device 40'". The size of the suction controller 90'" may allow the suction controller 90'" to abut and seal against the distal end 28 of the catheter 20, preventing suction applied through the lumen 24 of the catheter 20 from being transmitted and applied to the subject's body until the suction controller 90'" is advanced distally beyond the distal end 48'" of the tube 41'". The suction controller 90'" may be secured to the distal end 48'" of the tube 41'" of the retrieval device 40'". Thus, distal advancement of the retrieval device 40''' relative to the catheter 20 may distally advance the suction controller 90''' away from the distal end 28 of the catheter 20. Such an embodiment of the suction controller 90''' allows suction to be transmitted beyond the distal end 28 of the catheter 20 whenever the expandable section 50''' of the retrieval device 40''' is advanced distally or whenever the catheter 20 is retracted proximally, regardless of whether the expandable section 50''' is partially or fully deployed beyond the distal end 28 of the catheter 20.

[0065] As depicted, the suction controls 90'', 90''' may have a somewhat parabolic shape. Alternatively, the suction controls 90'', 90''' may be spherical or ovoid in shape. The suction controls 90'', 90''' may be formed from a material (e.g., a relatively hard rubber, etc.) that will seal the lumen 24 and / or the distal end 28 of the catheter 20. Arrangements such as those depicted by FIGS. 13-22 allow the user to instantly turn suction on and substantially turn suction off and / or slowly suction on by simply moving the retrieval device 40'', 40''' or the catheter 20.

[0066] 23-25, alternative embodiments of expanded expandable sections 50A, 50B, and 50C are shown, respectively. The expandable section 50A embodiment shown in FIG. 23 includes long, relatively straight struts 56A' at its proximal side and shorter struts 56A" and therefore smaller openings 52A" at its distal side. Such a configuration may allow the proximal side of the expandable section 50A to expand into soft objects, such as blood clots, and for the proximal side of the expandable section 50A to retract the object into the catheter 20 (not shown). The expandable section 50B embodiment shown in FIG. 24 includes similar features to the expandable section 50A embodiment shown in FIG. 23, with longer proximally located struts 56B' and shorter distally located struts 56B" and their associated smaller openings 52B".

[0067] The embodiment of the expandable section 50C shown in Figure 25 is elongated. Such an embodiment may be useful for engaging and removing an elongated object (e.g., a stent, a blood clot, etc.) from a subject's body.

[0068] The retrieval devices of the present disclosure can be used in a variety of contexts: In addition to medical and veterinary applications, the retrieval devices can be used in the construction, manufacturing, research, laboratory, aerospace, petroleum, and consumer markets where improved suction and control for the removal of fluids, liquids, gases, plasmas, and solids is needed.

[0069] While this disclosure provides many details, these details should not be construed as limiting the scope of any of the appended claims, but rather as providing merely illustrations of some embodiments of the elements and features of the disclosed subject matter. Other embodiments of the disclosed subject matter, and other embodiments of those elements and features, are possible without departing from the spirit or scope of any of the claims. Features from different embodiments may be employed in combination. Accordingly, the scope of each claim is limited only by its plain language and its legal equivalents.

Claims

1. 1. A retrieval device for engaging an object and removing said object from a small space, comprising: Tube and an expandable section defined in a distal section of the tube, the expandable section including an arrangement of slits defining a plurality of struts that rotate from a circumferential orientation to a radial orientation to engage the object when the expandable element expands and rotate back to the circumferential orientation when the expandable element at least partially contracts to grasp the object.

2. The retrieval device of claim 1 , wherein the expandable section is self-expandable.

3. The retrieval device of claim 1 , wherein the expandable section is manually expandable.

4. The retrieval device of claim 1 , wherein the tube comprises a hypotube.

5. The retrieval device of claim 4 , wherein the hypotube comprises a metal hypotube.

6. The retrieval device of claim 5 , wherein the metal hypotube comprises a shape memory alloy.

7. 4. The retrieval device of claim 1, further comprising a processing access section adjacent to and continuous with the expandable section, the processing access section including access slits continuous with at least some of the slits in the expandable section, the processing access section having an outer diameter substantially the same as an outer diameter of the tube.

8. 4. The retrieval device of claim 1, wherein the arrangement of posts comprises a brickwork arrangement.

9. A suction control on the tube The retrieval device of claim 1 , further comprising:

10. The retrieval device of claim 9 , wherein the suction controller is located distal to the expandable section.

11. The retrieval device of claim 9 , wherein the suction controller is located proximal to the expandable section.

12. A retrieval device according to any one of claims 1 to 3; a catheter having a lumen for receiving the retrieval device, including the expandable section of the retrieval device; A medical device assembly comprising:

13. a slider for moving the retrieval device relative to the catheter; The medical device assembly of claim 12 further comprising:

14. The medical device assembly of claim 13 , wherein the slider also moves the catheter relative to the retrieval device.

15. 1. A method for retrieving an object from a small space, comprising: advancing a distal end of a catheter into the small space adjacent the location of the object; deploying an expandable section of a retrieval device from the distal end of the catheter and expanding the expandable section of the retrieval device to engage the object; removing the object from the body of the subject while the object is engaged; A method comprising:

16. 16. The method of claim 15, wherein advancing the distal end of the catheter into the small space comprises advancing the distal end of the catheter into or slightly past the object.

17. 17. The method of claim 16, wherein deploying the expandable section of the retrieval device comprises retracting the catheter while the expandable section remains substantially in place.

18. advancing the distal end of the catheter into the small space includes advancing the distal end of the catheter to a position near the object; 16. The method of claim 15, wherein deploying the expandable section of the retrieval device comprises distally advancing the expandable section out of the distal end of the catheter.

19. 19. The method of any of claims 15 to 18, wherein removing the object comprises proximally retracting the expandable section toward or at least partially into the catheter.

20. Selectively applying suction to the object by moving the retrieval device and / or the catheter.

19. The method of any of claims 15 to 18, further comprising:

21. 1. A method for manufacturing an expandable device, comprising: defining an expandable section of the expandable device from a tube; defining a treatment access section from the tube adjacent and contiguous with the expandable section; opening the processing access section; introducing a forming mandrel into the processing access section; forcing the forming mandrel from the treatment access section into the expandable section; constraining the mandrel within the expandable section, including constraining the treatment access section in a contracted configuration with a collar; annealing the expandable section and the treatment access section to define an expanded shape of the expandable element and to maintain the treatment access section in the contracted configuration; A method comprising:

22. After the annealing, After opening the processing access section, forcing the forming mandrel from the expandable section into the processing access section; removing the forming mandrel from the processing access section; 22. The method of claim 21 further comprising:

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