Interventional systems and associated devices and methods

Abstract

Devices and systems for engaging an obstruction within a body lumen are disclosed herein. According to some examples, the present technology includes an elongate member having a proximal end portion, a distal end portion, and a longitudinal axis extending therebetween. The distal end portion of the elongate member can be configured to be positioned in a body lumen proximate an obstruction. The device can further include an obstruction engaging element disposed at the distal end portion of the elongate member, with the obstruction engaging element comprising a tapered body and a rib wrapped helically around an outer surface of the tapered body. The obstruction engaging element is configured to be rotated while in contact with the obstruction to advance the obstruction engaging element into or retract the obstruction engaging element out of the obstruction.

Description

INTERVENTIONAL SYSTEMS AND ASSOCIATED DEVICES AND METHODSCROSS-REFERENCE TO RELATED APPLICATIONS[0001| This application claims the benefit of priority to U.S. Provisional Application No. 63 / 489,727, filed March 10, 2023, which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] The present technology generally relates to treatment of occluded body lumens. In particular, the present devices and method relate engaging and / or crossing occlusions.BACKGROUND

[0003] Deep vein thrombosis (DVT) is a condition comprising a blood clot in a deep vein, usually a leg vein though they can also occur in arm veins. Symptoms include pain, swelling, tenderness, and / or discoloration in the affected limb. If untreated, it can lead to worsening of symptoms and complications such as post-thrombotic syndrome with symptoms of chronic pain, swelling, and skin discoloration, or pulmonary embolism (PE), a very serious and lifethreatening condition. Pharmacologic treatments include blood-thinning medications or thrombolytic drugs. More recently, percutaneous catheters have been developed for the more rapid removal of clot to remove the blockage and prevent PE. These include catheters which can deliver thrombolytic agents to the site of the clot, in some cases in combination with aspiration and / or the disruption of the clot into smaller pieces. Other catheters mechanically capture and remove clot without thrombolytic agents, thereby reducing the bleeding risk incurred by these drugs. An early example of this is the Fogarty Balloon Thrombectomy catheter. More recent examples include the ClotTriever® (Inari Medical, Irvine, CA), RevCore™ (Inari Medical, Irvine, CA), and the ReVene® Thrombectomy Catheter (Vetex Medical, Galway, Ireland).

[0004] Unfortunately, many of these therapies have limited success for partial or full blockages caused by chronic thrombus (i.e., a thrombus over one or two months old). As the clot remains in the limb over a period of months, the initial thrombus transforms into an acute fibrin structure and / or a chronic collagen structure which is tougher and more firmly adhered to the wall. Chronic thrombus may take the form of fibrous trabeculae or membranes stretching into and across the vein lumen (also known as venous synechiae). Further, the thrombusbecomes more firmly attached to the wall. Catheter-based thrombolysis or thrombectomy devices have a lower success rate in removing these blockages. Venous synechiae may also prevent optimal treatment of venous obstruction by balloon angioplasty or stenting, as the fibrous structures prevent permanent stretching of the vessel wall. There is a need for an improved endovascular thrombectomy device which is able to successfully remove chronic thrombus.SUMMARY

[0005] The subject technology is illustrated, for example, according to various aspects described below, including with reference to FIGS. 1 A-l 1. Various examples of aspects of the subject technology are described as numbered examples (1, 2, 3, etc.) for convenience. These are provided as examples and do not limit the subject technology.1. A device for engaging an obstruction within a body lumen, the device comprising: an elongate member having a proximal end portion, a distal end portion, and a longitudinal axis extending between the proximal and distal end portions, wherein the distal end portion of the elongate member is configured to be positioned in the body lumen proximate the obstruction; and an obstruction engaging element disposed at the distal end portion of the elongate member, the obstruction engaging element comprising a tapered body and a rib wrapped helically around an outer surface of the tapered body, wherein the obstruction engaging element is configured to be rotated while in contact with the obstruction to advance the obstruction engaging element into or retract the obstruction engaging element out of the obstruction.2. The device of Example 1, wherein the tapered body and the rib comprise separate components, and wherein the rib is adhered to the outer surface of the tapered body.3. The device of Example 1, wherein the rib is integrally formed with the tapered body such that the rib comprises a helical projection of the tapered body.4. The device of any one of Examples 1 to 3, wherein the tapered body extends between a proximal end and a distal end and has a length measured therebetween, and wherein the rib extends along the entire length of the tapered body.5. The device of any one of Examples 1 to 3, wherein the tapered body extends between a proximal end and a distal end and has a length measured therebetween, and wherein the rib extends along only a portion of the length of the tapered body.6. The device of any one of Examples 1 to 5, wherein the tapered body extends between a proximal end and a distal end, and wherein the tapered body comprises a rounded distal end.7. The device of any one of Examples 1 to 5, wherein the tapered body extends between a proximal end and a distal end, and wherein the tapered body comprises a flat distal end.8. The device of any one of Examples 1 to 7, wherein the rib has a circular or ovular axial cross-sectional shape.9. The device of any one of Examples 1 to 7, wherein the rib has a triangular axial cross-sectional shape.10. The device of any one of Examples 1 to 7, wherein the rib has a square or rectangular axial cross-sectional shape.11. The device of any one of Examples 1 to 10, wherein a pitch of the rib varies.12. The device of any one of Examples 1 to 10, wherein a pitch of the rib is substantially constant.13. The device of any one of Examples 1 to 12, wherein obstruction engaging element is rigidly coupled with the elongate member to such that rotational and / or translationalmovement of the elongate member causes a corresponding rotational and / or translational movement of the obstruction engaging element.14. The device of any one of Examples 1 to 13, wherein the elongate member is a solid rod.15. The device of any one of Examples 1 to 14, wherein the elongate member is a tubular shaft defining a lumen therethrough.16. The device of any one of Examples 1 to 15, wherein the tapered body defines a lumen extending therethrough.17. The device of any one of Examples 1 to 16, wherein the tapered body comprises a solid structure and does not define a lumen extending therethrough.18. A device for engaging an obstruction within a body lumen, the device comprising: an elongate member having a proximal end portion, a distal end portion, and a longitudinal axis extending between the proximal and distal end portions, wherein the distal end portion of the elongate member is configured to be positioned in the body lumen proximate the obstruction; and an obstruction engaging element disposed at the distal end portion of the elongate member, the obstruction engaging element comprising a tapered body, the tapered body defining a groove extending helically around an outer surface of the tapered body, wherein the obstruction engaging element is configured to be rotated while in contact with the obstruction to advance the obstruction engaging element into or retract the obstruction engaging element out of the obstruction.19. The device of Example 18, wherein the tapered body extends between a proximal end and a distal end and has a length measured therebetween, and wherein the groove extends along the entire length of the tapered body.20. The device of Example 19, wherein the tapered body extends between a proximal end and a distal end and has a length measured therebetween, and wherein the groove extends along only a portion of the length of the tapered body.21. The device of any one of Examples 18 to 20, wherein the tapered body extends between a proximal end and a distal end, and wherein the tapered body comprises a rounded distal end.22. The device of any one of Examples 18 to 21, wherein the tapered body extends between a proximal end and a distal end, and wherein the tapered body comprises a flat distal end.23. The device of any one of Examples 18 to 22, wherein a pitch of the groove varies.24. The device of any one of Examples 18 to 23, wherein a pitch of the groove is substantially constant.25. The device of any one of Examples 18 to 24, wherein obstruction engaging element is rigidly coupled with the elongate member to such that rotational and / or translational movement of the elongate member causes a corresponding rotational and / or translational movement of the obstruction engaging element.26. The device of any one of Examples 18 to 25, wherein the elongate member is a solid rod.27. The device of any one of Examples 18 to 26, wherein the elongate member is a tubular shaft defining a lumen therethrough.28. The device of any one of Examples 18 to 27, wherein the tapered body defines a lumen extending therethrough.29. The device of any one of Examples 19 to 28, wherein the tapered body comprises a solid structure and does not define a lumen extending therethrough.30. A method for advancing an endovascular medical device into or through a vascular obstruction using rotational motion, performed in conjunction with a distal tip have a helical or spiral geometry.31. The method of Example 30, wherein the rotational motion of the distal tip is performed while the distal tip is positioned over a guidewire.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Instead, emphasis is placed on illustrating clearly the principles of the present disclosure.

[0007] FIG. 1A is a side view of the distal portion of a treatment device configured in accordance with the present technology.

[0008] FIG. IB is an axial cross-sectional view of the obstruction engaging element of the treatment device shown in FIG. 1A, taken along line 1B-1B.

[0009] FIGS. 2, 3 and 4 show various examples of obstruction engaging elements configured in accordance with the present technology.

[0010] FIGS. 5A-5F are axial cross-sectional views of example ribs configured in accordance with the present technology.

[0011] FIGS. 6A-6D illustrate a method of using an obstruction engaging element of the present technology to cross an obstruction in the vasculature.

[0012] FIGS. 7, 8, 9 and 10 show various examples of obstruction engaging elements configured in accordance with the present technology.

[0013] FIG. 11 shows a lead-in region of an obstruction engaging element configured in accordance with the present technology.DETAILED DESCRIPTION

[0014] The present technology pertains broadly to the field of endovascular medical devices with application to any device that may benefit from mechanically assisted vascular obstructioncrossing. In some embodiments, the obstruction engagement elements of the present technology may be used in conjunction with a device or family of devices intended for debulking intralumenal material such as thrombus or collagen-based post thrombotic material from the deep veins of the venous system. The obstruction engagement elements of the present technology can be used with a variety of interventional devices and for a variety of treatments, such as mechanical thrombectomy catheters, atherectomy catheters, venous stents, high pressure balloons, distal protection baskets, crossing catheters, and others.

[0015] Many endovascular medical devices are designed to track through vasculature over a guidewire to the intended use location. Devices are often designed with an atraumatic or tapered tip to facilitate tracking and to prevent damage to the structure of the vessel. In some instances, obstructions within diseased vessels can substantially occlude the lumen and restrict guidewire and / or device passage. Various procedural techniques can be employed to attempt to traverse the obstruction but can still result in significant procedural delay or inability to fully cross.

[0016] In one specific example, DVT or post thrombotic syndrome (PTS) can result in partial to full obstruction of the deep venous system. This includes occlusion of the native vasculature such as the iliac, femoral, or popliteal veins, or of iliofemoral venous stents. The composition of the obstructive material can vary significantly with fresher thrombus having a primarily fibrin-based composition and the more developed post-thrombotic tissue having a collogen dominant composition. Further, the structure of the obstruction may range from complete luminal occlusion to a network of web-like trabeculae / synechia within the lumen.

[0017] Treatment of the DVT or PTS conditions often involves advancement of a catheterbased treatment device into the vasculature, over a guidewire, to debulk and remove the obstructive material. Under certain conditions, however, the guidewire or device may have extreme difficulty advancing through the obstruction based on the severity of the disease or composition of the tissue.

[0018] Use of a distal catheter tip having helical or spiral shaped geometry can benefit this process by providing a mechanical method for advancing the distal tip and advancing the catheter. By placing the distal catheter tip into contact with the obstruction and rotating, the helical or spiral geometry can become engaged with the tissue, enabling penetration into the occlusive material with a screw mechanism. Continued rotation of the distal tip feature canfurther advance the tip into the obstruction and provide a rigid guide for which the guidewire can be incrementally advanced.[00191 The present technology includes a distal catheter tip comprising an obstruction engaging element having a helical or spiral shaped screw geometry for improved catheter tracking and advancement through obstructed vasculature. The geometry of the tip provides a radially oriented ramped surface for mechanical engagement between the distal tip and obstructive material. When rotated, the distal tip slidably advances into or retracts out of the obstructive material based on the orientation of the tip geometry and direction of rotation. The magnitude of axial / linear movement per rotation is dependent on the pitch of the helical or spiral geometry and ability to maintain engagement between the tip and obstructive material.

[0020] FIG. 1 A shows the distal portion of a treatment device 100 configured in accordance with the present technology. FIG. IB is an axial cross-sectional view of the obstruction engaging element shown in FIG. 1A, taken along line 1B-1B. As shown in FIGS. 1A and IB, the treatment device 100 can comprise an elongate member 110 and an obstruction engaging element 101 disposed at the distal end portion 110b of the elongate member 110. The obstruction engaging element 101 can be configured to be positioned in a body lumen (e.g., a blood vessel, including an artery or a vein) at a treatment site proximate an obstruction in the body lumen. In some examples, the obstruction engaging element 101 comprises a body 102 and a rib 104 wrapped helically around an outer surface of the body 102. The treatment device 100 is configured to be advanced to the treatment site (see, for example, FIGS. 6A-6D) to place a distal portion of the obstruction engaging element 101 in contact with a proximal aspect of the obstruction. The treatment device 100 can then be manipulated to rotate the obstruction engaging element 101 while in contact with the obstruction to advance the obstruction engaging element 101 into or retract the obstruction engaging element 101 out of the obstruction. The helical rib 104 resists pressure (normal to the radially outer surface of the rib 104) by converting mechanical torque into a linear force, leveraging friction and the wedge action of each turn of the rib 104.

[0021] The elongate member 110 can have a proximal portion (not shown) configured to be positioned at an extracorporeal location for manipulation by the user. In some examples, the elongate member 110 and / or obstruction engaging element 101 can be configured to be advanced to the treatment site over a guidewire. In these and other embodiments, the elongate member 110 can comprise a tubular shaft defining a lumen extending therethrough and continuous with a lumen 114 (see FIG. IB) extending through the obstruction engagingelement 101. In other embodiments, the elongate member 110 and / or obstruction engaging element 101 can comprise a solid structure (e.g., no lumen).[00221 At least a portion of the body 102 of the obstruction engaging element 101 can taper distally to facilitate advancement into and retraction out of the obstruction. For example, as shown in FIG. 1A, in some examples the body 102 can comprise a cylindrical proximal region 108 and a tapered (e.g., conical) distal region 106 extending distally from the proximal region 108. The cylindrical proximal region 108 can be directly coupled to the distal end portion of the elongate member 110. For instance, the distal end portion 110b of the elongate member 110 can be disposed within a lumen defined by the proximal region 108 of the obstruction engaging element 101. In some embodiments, the distal end portion 110b of the elongate member 110 is positioned over and / or around the proximal region 108 of the obstruction engaging element 101 (e.g., the proximal region 108 is positioned within a lumen of the elongate member 110). In yet other embodiments, the proximal region 108 of the obstruction engaging element 101 may be configured to mate with one or more complementary features at the distal end portion 110b of the elongate member 110. For example, the proximal region 108 of the obstruction engaging element 101 may include a protrusion configured to be received by a recess at the distal end portion 110b of the elongate member 110, or vice versa. Other engaging means are also possible, such as a key and keyway structure.

[0023] While the obstruction engaging elements disclosed herein, including but not limited to obstruction engaging element 101, are shown with tapered distal regions, any of the obstruction engaging elements of the present technology can have a substantially constant diameter along their lengths such that no portion of the obstruction engaging element is tapered. It will be appreciated that all of the featured described herein with reference to the tapered embodiments equally apply to obstruction engaging elements with uniform diameters.

[0024] In some embodiments, the obstruction engaging element 101 is rigidly coupled to the elongate member 110 such that torque or rotational force applied to the elongate member 110 is directly transferred to the obstruction engaging element 101. In other embodiments, the obstruction engaging element 101 may be mechanically decoupled from the elongate member 110 such that rotation and / or translation of the elongate member 110 does not cause a corresponding rotation and / or translation of the obstruction engaging element 101. For example, the obstruction engaging element 101 may be coupled to a separate delivery member (not shown) responsible for causing translation and / or rotation of the obstruction engaging element 101. The separate delivery member may be positioned within a lumen of theelongate member 110, over the elongate member 110 (such that the elongate member 110 is positioned within a lumen of the delivery member), or run parallel to the elongate member 110.[00251 In some embodiments, a cross-sectional dimension of the proximal region 108 of the body 102 varies along its length. In certain embodiments, the entire length of the obstruction engaging element 101 (e.g., both the proximal and distal regions 108, 106) can be tapered or the entire length can have a substantially constant diameter. As shown in FIG. 1A, in some examples the rib 104 may extend along only the tapered distal region 106. In other embodiments, the rib 104 may extend around both the proximal and distal regions 108, 106. In some cases, the rib 104 may extend along only a portion of the tapered distal region 106 (for example as described below with reference to FIG. 3). In some examples, the rib 104 extends proximally beyond the obstruction engaging element 101 and wraps partially or completely (one or more loops) around a distal portion of the elongate member 110.[00261 The body 102 of the obstruction engaging element 101 can terminate distally at a distal face 112 that surrounds a distal opening (if the obstruction engaging element 101 is a hollow structure). The distal face 112 can be flat (as shown) or rounded. In some examples, the body 102 can include a lead-in member to facilitate the initial gripping and / or engaging of the obstruction, as discussed in greater detail below with reference to FIG. 11.[00271 The rib 104 can extend helically around all or a portion of the length of the body 102 according to a pitch P measured between successive loops and a helix angle a measured between a longitudinal axis L of the device 100 and the rib 104. The pitch P may be the same or vary between successive loops, and the helix angle a may be the same or vary between successive loops. Moreover, the rib 104 can have a clockwise or counterclockwise orientation. The pitch P may be selected depending on the desired advancement speed (a larger pitch will cause the obstruction engaging element 101 to advance faster / translate farther per turn), gripping force (a larger pitch may reduce the obstruction engaging element’s gripping force on the obstruction), and precision (a finer pitch enables more precise adjustments). Likewise, the helix angle a may be selected depending on the desired efficiency (a greater helix angle has lesser frictional losses and therefore has higher efficiency) and torque input (a greater helix angle requires more torque to rotate the obstruction engaging element 101).

[0028] As but one of many examples, FIG. 2 shows a treatment device 200 having an obstruction engaging element 201 similar to the obstruction engaging element 101 described with reference to FIGS. 1 A and IB, but with the rib 104 having a varying pitch along the lengthof the tapered distal region 106. The rib 104 can be wrapped around the body 102 such that pairs of loops are spaced apart from adjacent pairs of loops by a distance greater than the distance between the individual loops comprising the pairs of loops. Said another way, the rib 104 can have a pitch that alternates between successive turns between a first pitch Pl and a second pitch P2 less than the first pitch Pl .

[0029] As yet another example, FIG. 3 shows a treatment device 300 having an obstruction engaging element 301 similar to the obstruction engaging element 101 described with reference to FIGS. 1 A and IB, but with the rib 104 having a pitch that is substantially zero (e.g., tightly wound, with nominal space between successive turns). Such a design can be advantageous for providing greater precision when penetrating the obstructive material, and may be more flexible. Also as demonstrated in FIG. 3, the tapered distal region 106 can have a first portion 124 along which the rib 104 is wound and a second portion 126, distal of the first portion 124, without the rib 104. While this variation is shown with respect to an obstruction engaging element 101 having a pitch of substantially zero, it will be appreciated that such a design (including a ribbed first portion 124 and non-ribbed second portion 126) can be utilized on an obstruction engaging element with any pitch or helix angle along the first portion 124.

[0030] In some examples, the obstruction engaging element 101 and / or body 102 can have one or more fluted regions to facilitate removal of obstructive material as the obstruction engaging element is advanced into the obstruction. FIG. 4 shows a non-exclusive example of an obstruction engaging element 401 having a plurality of flutes 122 extending longitudinally along the body 102. In some embodiments, the body 102 includes a single flute. The flutes 122 may extend along all or a portion of the length of the body 102 and / or obstruction engaging element 101. In some examples, the flutes may extend helically around the body 102, for instance in between successive turns of the rib 104. To form the flutes, one or more portions of the body 102 and / or rib 104 may be removed.

[0031] As shown in FIG. 1A, the rib 104 extends radially away from the outer surface of the body 102. FIGS. 5A-5F show non-exclusive examples of different cross-sectional profiles of the ribs 104. In all embodiments, the rib 104 includes a radially outermost surface 500 and sidewalls 502 extending downwardly from the outermost surface 500 to the body 102. As shown in FIG. 5 A, in some examples the rib 104 has a circular cross-sectional shape (or ovular, in some embodiments) with a rounded outermost surface 500 and rounded sidewalls 502 that are concave towards one another. As shown in FIG. 5B, the rib 104 can have a square cross- sectional shape (or rectangular, in some embodiments) with a substantially flat and / or linearoutermost surface 500 and substantially flat or linear sidewalls 502. As shown in FIG. 5C, in some embodiments the rib 104 can have a triangular cross-sectional shape comprising two substantially linear sidewalls 502 angled towards one another in a direction away from the body 102. In these and other examples, the outermost surface 500 can comprise a sharpened or blunted (e.g., rounded) edge 500 where the two sidewalls 502 come together. As shown in FIG. 5D, in some examples the rib 104 can have curved sidewalls 502 that extend away from the body 102 substantially parallel to one another then curve towards one another until meeting an outermost surface 500, which may comprise a sharp or blunt edge. The curved portions of the sidewalls 502 can be concave towards one another such that the rib 104 presents a sidewall surface that is convex towards the obstruction. FIG. 5E depicts another example embodiment in which the sidewalls 502 have a substantially linear proximal portion 502a followed by a curved distal portion 502b. The distal portions 502b can be curved towards one another, thereby presenting a concave sidewall to the obstruction. The sidewalls 502 can meet at outermost surface 500, which may be a sharpened or blunted edge. As shown in FIG. 5F, in some embodiments the sidewalls 502 have a substantially linear proximal portion 502a followed by a curved distal portion 502b. In contrast the sidewalls 502 of FIG. 5E, in FIG. 5F the sidewalls curve away from one another, thus presenting a concave surface to the obstruction. Also unlike the example shown in FIG. 5E, because the sidewalls 502 curve away from one another, the outermost surface 500 comprises a substantially linear or flat atraumatic surface (rather than a narrow edge).[00321 In some examples, the rib 104 can comprise a structure initially provided separate from the body 102 and fixed to the outer surface of the body 102 during manufacturing. For example, the rib 104 can comprise a biocompatible or non-biocompatible metal, polymer, or composite strand or strip of material (such as a wire, a strip cut from a sheet of material, a 3D- printed strip, etc.) that is affixed to the body 102. In other embodiments, the rib 104 and body 102 comprise a unitarily formed structure (e.g., integral with one another) such that the rib 104 is an extension of the material of the body 102. The rib can be partially or completely formed by a radiopaque material, or may include a radiopaque coating.

[0033] The rib 104 and the body 102 may be comprised of the same or different materials and / or may have the same or different material properties. For example, in some examples the rib 104 can be formed of a metal, while the body 102 is formed of a polymer. According to certain examples, the body 102 can be more flexible and / or softer than the rib 104. In other embodiments, the body 102 and rib 104 are substantially equally rigid / flexible and / or soft / hard.The rib 104 and and / or body 102 can be formed via forging, casting, swaging, insert molding, over molding, machining, 3D printing, and / or other methods.[00341 The length and cross-sectional dimension of the obstruction engaging element 101 can be tailored to the desired use, and depending on the size of the elongate member 110 and the intended guidewire to be used with the system (if one at all). In some examples, the proximal end of the body 102 can have a cross-sectional dimension of from about 0.130 inches to about 0.150 inches and the distal end of the body 102 (at the distal face 112) can have a cross-sectional dimension of from about 0.020 inches to about 0.070 inches.

[0035] The rib 104 may have a fixed diameter or may be expandable / collapsible. For example, the rib 104 can be inflated to increase a cross-sectional dimension of the rib 104 along its length. In other embodiments, the rib 104 can be mechanically actuated to extend radially away from the body 102.

[0036] FIGS. 6A-6D show an example method of using the treatment devices of the present technology to penetrate and / or cross an obstruction O in a blood vessel V. As previously mentioned, other applications are possible.

[0037] According to some methods of use, the treatment device 100, including the elongate member 110 and the obstruction engaging element 101 can be advanced over a guidewire GW to a treatment site proximate an obstruction O. The guidewire GW can be positioned, for example, just proximal of or in contact with a portion of the obstruction O (as shown in FIG. 6A), which is blocking passage of the guidewire GW. As shown in FIG. 6B, the device 100 can then be advanced over the guidewire GW until a distal portion of the obstruction engaging element 101 is in contact with the obstruction O. As depicted in FIG. 6C, the obstruction engaging element 101 can then be rotated in a first direction (indicated by the arrow) to advance the obstruction engaging element 101 into the obstruction O. As previously discussed, rotation of the obstruction engaging element 101 may be achieved by rotating the elongate member 110 (if a rigid connection between the obstruction engaging element 101 and the elongate member 110, or by rotating a separate delivery member (not shown) extending through or over the elongate member 110 and that is rigidly coupled to the obstruction engaging element 101. With continued rotation and forward advancement, the obstruction engaging element is eventually positioned on the distal side of the obstruction, as shown in FIG. 6D.

[0038] FIG. 7 shows the distal portion of a treatment device 700 configured in accordance with the present technology. As shown in FIG. 7, the treatment device 700 can comprise anelongate member 110 and an obstruction engaging element 701 disposed at the distal end portion 110b of the elongate member 110. The obstruction engaging element 701 can be configured to be positioned in a body lumen (e.g., a blood vessel, including an artery or a vein) at a treatment site proximate an obstruction in the body lumen. In some examples, the obstruction engaging element 701 comprises a body 702 that defines a groove 704 that wraps helically around an outer surface of the body 702. The treatment device 700 is configured to be advanced to the treatment site to place a distal portion of the obstruction engaging element 701 in contact with a proximal aspect of the obstruction. The treatment device 700 can then be manipulated to rotate the obstruction engaging element 701 while in contact with the obstruction to advance the obstruction engaging element 701 into or retract the obstruction engaging element 701 out of the obstruction.[00391 In some embodiments, a cross-sectional dimension of the proximal region 708 of the body 702 varies along its length. In certain embodiments, the entire length of the obstruction engaging element 701 (e.g., both the proximal and distal regions 708, 706) can be tapered, and in other examples the entire length of the obstruction engaging element 701 can have a substantially constant diameter. As shown in FIG. 7, in some examples the groove 704 may extend along only the tapered distal region 706. In other embodiments, the groove 704 may extend around both the proximal and distal regions 708, 706. In some cases, the groove 704 may extend along only a portion of the tapered distal region 706. For example, the tapered distal region 706 of the obstruction engaging element 701 can have a proximal portion that includes the helical groove, and a distal portion that is without the groove.[00401 The groove 704 can be formed via subtractive manufacturing, additive manufacturing, insert molding, casting, and other suitable methods. The body 702 can be formed of a biocompatible or non-biocompatible a metal, a polymer, and / or a suitable composite material.[0041J The groove 704 can extend helically around all or a portion of the length of the body 702 according to a pitch P measured between successive loops and a helix angle a measured between a longitudinal axis L of the device 700 and the groove 704. The pitch P may be the same or vary between successive loops. As but one of many examples, FIG. 8 shows a treatment device 800 having an obstruction engaging element 801 similar to the obstruction engaging element 701 described with reference to FIG. 7, but with a pitch P less than a pitch P of obstruction engaging element 701.

[0042] The helix angle a of the groove 704 may be the same or vary between successive loops, and the groove 704 can have a clockwise or counterclockwise orientation. The pitch P may be selected depending on the desired advancement speed (a larger pitch will cause the obstruction engaging element 701 to advance faster / translate farther per turn), gripping force (a larger pitch may reduce the obstruction engaging element’s gripping force on the obstruction), and precision (a finer pitch enables more precise adjustments). Likewise, the helix angle a may be selected depending on the desired efficiency (a greater helix angle has lesser frictional losses and therefore has higher efficiency) and torque input (a greater helix angle requires more torque to rotate the obstruction engaging element 701).

[0043] In some examples, the obstruction engaging element 701 and / or body 702 can have one or more fluted regions to facilitate removal of obstructive material as the obstruction engaging element 701 is advanced into the obstruction. The obstruction engaging element 701 can have one or more flutes (not shown) extending longitudinally along the body 702, as described above with reference to FIG. 4.

[0044] FIG. 9 shows the distal portion of another treatment device 900 configured in accordance with the present technology. As shown in FIG. 9, the treatment device 900 can comprise an elongate member 110 and an obstruction engaging element 901 disposed at the distal end portion 110b of the elongate member 110. The obstruction engaging element 901 can be configured to be positioned in a body lumen (e.g., a blood vessel, including an artery or a vein) at a treatment site proximate an obstruction in the body lumen. In some examples, the obstruction engaging element 901 comprises a proximal region 908 and a distal region 906. The proximal region 908 can comprise a cylindrical portion while the distal region 906 can comprise a helical structure 920 that forms multiple loops around the longitudinal axis of the device 900, with helical gaps 922 defined between successive loops (similar to a corkscrew). The helical structure 920 can define a cross-sectional dimension that decreases distally, thus giving the helical structure 920 a tapered shape (and such that the loops get progressively smaller). In other embodiments, the helical structure 920 can have a substantially constant diameter.

[0045] In some variations, all or a portion of the proximal region 908 has a distally tapering cross-sectional dimension such that the helical structure 920 is positioned between two structures with continuous outer surfaces. In other examples, the obstruction engaging element 901 does not include a cylindrical proximal region 908 and is formed entirely of the helical structure 920.

[0046] Similar to the other treatment devices disclosed herein, the treatment device 900 is configured to be advanced to the treatment site to place a distal portion of the obstruction engaging element 901 in contact with a proximal aspect of the obstruction. The treatment device 900 can then be manipulated to rotate the obstruction engaging element 901 while in contact with the obstruction to advance the obstruction engaging element 901 into or retract the obstruction engaging element 901 out of the obstruction.

[0047] The cross-sectional shape of the helically extending member that forms the helical structure 920 can be any suitable shape, such as a rounded shape (e.g., circle, oval, etc.), a square, a rectangle, a polygon, or other suitable shapes. The helically extending member may have one or more sharpened edges, or may have rounded and / or atraumatic edges. The distal face 912 of the helical structure 920 may be blunted, pointed, or tapered.

[0048] The obstruction engaging element 920 can be coupled to the distal end portion of the elongate member 110 by structures and methods similar to those described above with reference to FIGS. 1A and IB. The helical structure 920 can be formed via subtractive manufacturing, additive manufacturing, insert molding, casting, and other suitable methods. The helical structure 920 can be formed of a biocompatible or non-biocompatible metal, polymer, and / or suitable composite material.

[0049] FIG. 10 shows a treatment device 1000 having an obstruction engaging element 1001 similar to the obstruction engaging element 901 described with reference to FIG. 9, but with a nosecone 924 disposed at a distal end of the helical structure 920. As such, the tapered distal region 906 can have a first portion 1024 comprising the helical structure 920 and a second portion 1026, distal of the first portion 1024, having a continuous outer surface that defines a lumen therethrough and / or cavity therein. The nosecone 924 may have an opening 926 at its distal tip.

[0050] FIG. 11 shows the distal portion of an obstruction engaging element 1101 of a treatment device 1100 configured in accordance with the present technology. As shown in FIG. 11, the distal end of any of the obstruction engaging elements 1101 of the present technology can include one or more lead-in features configured to initiate engagement and penetration of the obstruction. In some embodiments, the lead-in region comprises a plurality of distinct ridges 1132 at the distal end of the body 1102. The ridges 1132 can project distally away from the distal end, and in some cases may taper distally to a distal edge 1134. Other variations are possible.

[0051] The present technology can further include an obstruction engaging element comprising a plurality of articulating segments. The segments can be configured to rotate and / or pivot by a limited amount relative to one another to enable bending of the obstruction engaging element along the longitudinal axis. Each of the segments can be relatively rigid and can define a central opening that allows a guidewire to pass therethrough.Conclusion

[0052] Other embodiments in addition to those described herein are within the scope of the technology. Additionally, several other embodiments of the technology can have different configurations, components, or procedures than those described herein. A person of ordinary skill in the art, therefore, will accordingly understand that the technology can have other embodiments with additional elements, or the technology can have other embodiments without several of the features shown and described above with reference to FIGS. 1 A-l 1.

[0053] The descriptions of embodiments of the technology are not intended to be exhaustive or to limit the technology to the precise form disclosed above. Where the context permits, singular or plural terms may also include the plural or singular term, respectively. Although specific embodiments of, and examples for, the technology are described above for illustrative purposes, various equivalent modifications are possible within the scope of the technology, as those skilled in the relevant art will recognize. For example, while steps are presented in a given order, alternative embodiments may perform steps in a different order. The various embodiments described herein may also be combined to provide further embodiments.

[0054] As used herein, the terms “generally,” “substantially,” “about,” and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent variations in measured or calculated values that would be recognized by those of ordinary skill in the art.

[0055] Moreover, unless the word “or” is expressly limited to mean only a single item exclusive from the other items in reference to a list of two or more items, then the use of “or” in such a list is to be interpreted as including (a) any single item in the list, (b) all of the items in the list, or (c) any combination of the items in the list. Additionally, the term "comprising" is used throughout to mean including at least the recited feature(s) such that any greater number of the same feature and / or additional types of other features are not precluded. It will also be appreciated that specific embodiments have been described herein for purposes of illustration, but that various modifications may be made without deviating from the technology. Further,while advantages associated with certain embodiments of the technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the technology. Accordingly, the disclosure and associated technology can encompass other embodiments not expressly shown or described herein.

Claims

CLAIMSI / We claim:

1. A device for engaging an obstruction within a body lumen, the device comprising: an elongate member having a proximal end portion, a distal end portion, and a longitudinal axis extending between the proximal and distal end portions, wherein the distal end portion of the elongate member is configured to be positioned in the body lumen proximate the obstruction; and an obstruction engaging element disposed at the distal end portion of the elongate member, the obstruction engaging element comprising a tapered body and a rib wrapped helically around an outer surface of the tapered body, wherein the obstruction engaging element is configured to be rotated while in contact with the obstruction to advance the obstruction engaging element into or retract the obstruction engaging element out of the obstruction.

2. The device of Claim 1, wherein the tapered body and the rib comprise separate components, and wherein the rib is adhered to the outer surface of the tapered body.

3. The device of Claim 1, wherein the rib is integrally formed with the tapered body such that the rib comprises a helical projection of the tapered body.

4. The device of any one of Claims 1 to 3, wherein the tapered body extends between a proximal end and a distal end and has a length measured therebetween, and wherein the rib extends along the entire length of the tapered body.

5. The device of any one of Claims 1 to 3, wherein the tapered body extends between a proximal end and a distal end and has a length measured therebetween, and wherein the rib extends along only a portion of the length of the tapered body.

6. The device of any one of Claims 1 to 5, wherein the tapered body extends between a proximal end and a distal end, and wherein the tapered body comprises a rounded distal end.

7. The device of any one of Claims 1 to 5, wherein the tapered body extends between a proximal end and a distal end, and wherein the tapered body comprises a flat distal end.

8. The device of any one of Claims 1 to 7, wherein the rib has a circular or ovular axial cross-sectional shape.

9. The device of any one of Claims 1 to 7, wherein the rib has a triangular axial cross-sectional shape.

10. The device of any one of Claims 1 to 7, wherein the rib has a square or rectangular axial cross-sectional shape.

11. The device of any one of Claims 1 to 10, wherein a pitch of the rib varies.

12. The device of any one of Claims 1 to 10, wherein a pitch of the rib is substantially constant.

13. The device of any one of Claims 1 to 12, wherein obstruction engaging element is rigidly coupled with the elongate member to such that rotational and / or translational movement of the elongate member causes a corresponding rotational and / or translational movement of the obstruction engaging element.

14. The device of any one of Claims 1 to 13, wherein the elongate member is a solid rod.

15. The device of any one of Claims 1 to 14, wherein the elongate member is a tubular shaft defining a lumen therethrough.

16. The device of any one of Claims 1 to 15, wherein the tapered body defines a lumen extending therethrough.

17. The device of any one of Claims 1 to 16, wherein the tapered body comprises a solid structure and does not define a lumen extending therethrough.

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