Patent ID: 12201312

SUMMARY OF INVENTION

In some embodiments, the present disclosure provides a catheter that may include a catheter proximal end (which may be open); a catheter open distal end; a length extending from the catheter proximal end to the catheter open distal end; a height perpendicular to the length; a width perpendicular to the length and height; a hollow interior/lumen extending from the catheter proximal end to the catheter open distal end; a proximal segment that may comprise a proximal segment proximal end, a proximal segment distal end located proximal to the catheter open distal end, a proximal segment length extending from the proximal segment proximal end to the proximal segment distal end and parallel to the catheter length, a proximal segment width parallel to the catheter width, and/or a proximal segment height parallel to the catheter height; and/or a distensible segment that may comprise a distensible segment proximal end located distal to the proximal segment distal end, a distensible segment distal end located proximal to the catheter open distal end, a distensible segment length extending from the distensible segment proximal end to the distensible segment distal end and parallel to the catheter length, a distensible segment width parallel to the catheter width, and/or a distensible segment height parallel to the catheter height; a distal segment that may comprise a distal segment proximal end located distal to the distensible segment distal end, a distal segment distal end, a distal segment length extending from the distal segment proximal end to the distal segment distal end and parallel to the catheter length, a distal segment width parallel to the catheter width, and/or a distal segment height parallel to the catheter height.

Optionally, the catheter is intended for neurovascular use (e.g., as a distal access catheter or aspiration catheter). Optionally, the length of the catheter is from about 100 centimeters to about 165 centimeters. Optionally, the catheter comprises a relaxed configuration in which the proximal, distal and distensible segments are cylindrical in shape and comprise an inner diameter of from about 0.04 inches to about 0.10 inches. Optionally, the distensible segment is configured to undergo a conformational change (and the proximal and distal segments are configured to maintain a fixed cylindrical shape and length and diameter) when a linear force in the distal direction is applied to the catheter and, in turn, a linear force in the proximal direction is applied to the catheter open distal end. For example, optionally, when a surgeon attempts to push the catheter distally in a blood vessel when the catheter open distal end is lodged against a vessel wall (i.e., when a linear force in the distal direction is applied to catheter proximal end and, in response, a linear force in the proximal direction is applied to the proximal segment), the catheter is configured to self-adjust from the relaxed configuration to a distended configuration in which i) the cross-sectional height and/or width of the distensible segment is configured to increase, the distensible segment is configured to become non-cylindrical, and/or at least one side of the catheter in the distensible segment is configured to bulge outward, and ii) the cross-sectional width, cross-sectional height and length of the proximal and distal segments are configured to remain constant and the proximal and distal segments are configured to remain cylindrical. Optionally, in the distended configuration, the proximal segment does not kink. Optionally, the catheter is configured to self-adjust from the distended configuration to the relaxed configuration when the catheter open distal end dislodges from the vessel wall (i.e., when the linear force in the proximal direction acting on the catheter open distal end is removed). Optionally, in the distended configuration, the length of the distensible segment is configured to decrease. Optionally, in the distended configuration, the distensible segment is a non-cylindrical shape (e.g., one side of the distensible segment shortens and curves inward and an opposite side lengthens and bulges outward). Optionally, the length of the distensible segment is from about 5 millimeters to about 10 millimeters. Optionally, the length of the proximal segment is at least ten times greater than the length of the distensible segment and the length of the distal segment. Optionally, the length of the distensible segment is greater than the length of the distal segment. Optionally, the distal end of the distensible segment is located about 0.5 millimeters to about 5 millimeters from the catheter open distal end (e.g., preferably about 1.5 mm). Optionally, the catheter is coupled to a suction source. Optionally, the suction source is a syringe or pump. Optionally, the distal segment comprises a cylindrical metallic band located distal to the distensible segment distal end and adjacent to the catheter open distal end. Optionally, the cylindrical metallic band is located from about 0 millimeters to about 5 millimeters distal to the distensible segment distal end. Optionally, the cylindrical metallic band is located from about 0 millimeters to about 5 millimeters proximal to the catheter open distal end. Optionally, the cylindrical metallic band comprises a length parallel to the catheter length and further wherein the length of the cylindrical metallic band is less than the length of the distensible segment. Optionally, the cylindrical metallic band is more visible under x-ray as compared to the distensible segment when the catheter is located in a cranial blood vessel inside the body of a human and the x-ray is taken from outside the human's body. Optionally, the cylindrical metallic band, the proximal segment and the distal segment have substantially the same inner diameter in the relaxed configuration and further wherein the cylindrical metallic band, the proximal segment and the distal segment have substantially the same outer diameter in the relaxed configuration. Optionally, the cylindrical metallic band is comprised of tantalum, platinum and/or iridium. Optionally, the distal segment extends from the distensible segment distal end to the catheter open distal end. Optionally, the proximal segment extends from the open proximal end to the distensible segment proximal end. Optionally, the catheter further comprises a wall extending from at least the proximal segment to the distal segment (and preferably from the catheter proximal end to the catheter open distal end), the wall comprised of an inner layer (e.g., inner tube) surrounding the hollow interior and an outer layer (e.g., outer tube) extending around the inner tube, wherein the outer tube is attached to the inner tube in the proximal and distal segments, and further wherein the outer tube is not attached to the inner tube for at least a portion of the distensible segment. Optionally, the wall of at least a portion of the proximal segment and at least a portion of the distensible segment further comprises a plurality of ribs (e.g. a coil located between the outer tube and the inner tube). Optionally, for at least a portion of the distensible segment, the coil is attached to the inner tube but not to the outer tube, and further wherein, in the proximal segment, the coil is attached to the inner tube and the outer tube. Optionally, the coil extends around the inner tube in a helical manner, the coil comprising a variable coil pitch, and further wherein the coil pitch in the distensible segment is greater than the coil pitch in the proximal segment. Optionally, the wall further comprises a braid located between the coil and the outer tube. Optionally, the distal segment comprises a cylindrical metallic band located distal to the distensible segment distal end and adjacent to the catheter open distal end, with the cylindrical metallic band attached to the braid. Optionally, the coil pitch in the distensible segment is configured to change while the coil pitch in the proximal segment remains constant when the catheter self-adjusts from the relaxed configuration to the distended configuration. Optionally, for at least a portion of the distensible segment, the braid is attached to the inner tube but not to the outer tube, and further wherein, in the proximal segment and the distal segment, the braid is attached to the inner tube and the outer tube. Optionally, the coil pitch in the distensible segment is between about 0.006 to 0.040 inches and further wherein the coil pitch in the proximal segment is between about 0.002 to about 0.006 inches. Optionally, the coil pitch in the distensible segment is between about 0.015 to 0.040 inches and further wherein the coil pitch in the proximal segment is between about 0.002 to about 0.006 inches. Optionally, the coil is metallic (e.g., steel or nitinol). Optionally, the inner tube and the outer tube are comprised of an elastomeric material. Optionally, in the relaxed configuration, the catheter comprises a substantially constant inner diameter and a substantially constant outer diameter along the catheter length. Optionally, in the relaxed configuration, the catheter comprises an inner diameter of from about 0.06 to about 0.08 inches and an outer diameter of from about 0.08 to about 0.1 inches. Optionally, the catheter comprises a plurality of distensible segments, each distensible segment separated by a proximal segment. Optionally, the catheter is comprised of a biocompatible material and is sterile. Optionally, the distensible segment is configured to bend while the proximal segment and distal segment remains constant when the catheter self-adjusts from the relaxed configuration to the distended configuration. Optionally, the inner tube and/or the outer tube comprise a plurality of tubes joined together (e.g., the materials forming the inner and outer layer may be comprised of progressively softer materials distally to provide more flexibility—i.e., the distal tubes may be more flexible than the proximal tubes). Optionally, the braid, coil, outer tube, and/or inner tube extend substantially to the full length of the catheter (e.g., at least 90% of the full length of the catheter). For example, the distal end of the coil may be located under the cylindrical metallic band.

In still further embodiments, the present disclosure provides a method of using the catheter in a human vascular system comprising providing the catheter, inserting the catheter open distal end into the human vascular system and moving the catheter open distal end distally in the human blood vessel. Optionally, a human blood vessel of the human vascular system comprises a clot, the catheter proximal end is coupled to a suction source, and the method further comprises using suction to draw the clot toward the catheter distal end to remove the clot from the human blood vessel. Optionally, the method further comprises using a stent retriever in conjunction with the catheter to remove the clot from the human blood vessel. Optionally, the method further comprises pushing the catheter distally, allowing the catheter open distal end to contact and become stuck against a wall of a human blood vessel of the vascular system, and continuing to push the catheter proximal end distally so that the catheter open distal end moves towards a center of the human blood vessel to become dislodged from the vessel wall. Optionally, prior to the catheter open distal end becoming dislodged from the vessel wall, i) the height and/or width of the distensible segment increases, the distensible segment becomes non-cylindrical, and/or at least one side of the catheter bulges outward, and ii) the width, height and length of the proximal and distal segments stay constant and the proximal and distal segments remain cylindrical. Optionally, prior to the catheter open distal end moving towards the center of the human blood vessel to become dislodged from the vessel wall, the distensible segment moves away from the vessel wall then towards the vessel wall to cause the catheter open distal end to move towards the center of the vessel to become dislodged from the vessel wall. Optionally, the human blood vessel is the internal carotid artery. Optionally, the method further comprises moving a microcatheter or other neurovascular device distally through the hollow interior (e.g., to access a vessel distal to the ophthalmic artery).

In still further embodiments, the catheter is used in a method that comprises inserting the catheter open distal end into the human vascular system, passing the catheter distal end beyond the turns of the cavernous sinus and petrous bone. Optionally, the method further comprises applying suction to draw a clot or other object toward the catheter open distal end. Optionally, the method further comprises deploying a microcatheter or other neurovascular device from the open distal end.

In still further embodiments, the present disclosure provides a catheter that may include a catheter proximal end (which may be open); a catheter open distal end; a length extending from the catheter proximal end to the catheter open distal end; a height perpendicular to the length; a width perpendicular to the length and height; a hollow interior/lumen extending from the catheter proximal end to the catheter open distal end; a proximal segment that may comprise a proximal segment proximal end, a proximal segment distal end located proximal to the catheter open distal end, a proximal segment length extending from the proximal segment proximal end to the proximal segment distal end and parallel to the catheter length, a proximal segment width parallel to the catheter width, and/or a proximal segment height parallel to the catheter height; a distensible segment that may comprise a distensible segment proximal end located distal to the proximal segment distal end, a distensible segment distal end located proximal to the catheter open distal end, a distensible segment length extending from the distensible segment proximal end to the distensible segment distal end and parallel to the catheter length, a distensible segment width parallel to the catheter width, and/or a distensible segment height parallel to the catheter height; a distal segment that may comprise a distal segment proximal end located distal to the distensible segment distal end, a distal segment distal end, a distal segment length extending from the distal segment proximal end to the distal segment distal end and parallel to the catheter length, a distal segment width parallel to the catheter width, and/or a distal segment height parallel to the catheter height; and/or a wall that may be comprised of an inner tube, a coil and/or an outer tube. Optionally, the catheter includes one or more features described above, including, for example, the aforementioned metallic band, braid, coil pitch, and selective attachment of the outer tube to the inner tube, coil and braid. Optionally, the catheter is used in one or more of the methods described above.

In still further embodiments, the present disclosure provides a catheter that may include a catheter proximal end (which may be open); a catheter open distal end; a length extending from the catheter proximal end to the catheter open distal end; a height perpendicular to the length; a width perpendicular to the length and height; a hollow interior/lumen extending from the catheter proximal end to the catheter open distal end; a proximal segment that may comprise a proximal segment proximal end, a proximal segment distal end located proximal to the catheter open distal end, a proximal segment length extending from the proximal segment proximal end to the proximal segment distal end and parallel to the catheter length, a proximal segment width parallel to the catheter width, and/or a proximal segment height parallel to the catheter height; a distensible segment that may comprise a distensible segment proximal end located distal to the proximal segment distal end, a distensible segment distal end located proximal to the catheter open distal end, a distensible segment length extending from the distensible segment proximal end to the distensible segment distal end and parallel to the catheter length, a distensible segment width parallel to the catheter width, and/or a distensible segment height parallel to the catheter height; and/or distal segment that may comprise a distal segment proximal end located distal to the distensible segment distal end, a distal segment distal end, a distal segment length extending from the distal segment proximal end to the distal segment distal end and parallel to the catheter length, a distal segment width parallel to the catheter width, and/or a distal segment height parallel to the catheter height; and the catheter comprises one or more of the following features (alone or in any combination): i) wherein the distensible segment is more flexible than the proximal segment and the distal segment; ii) wherein at least a portion of a wall of the proximal segment and at least a portion of the distensible segment comprise a plurality of ribs (e.g., coils) spaced apart and further wherein the spacing between at least some of the adjacent ribs is greater in the distensible segment than in the proximal segment; iii) wherein a wall of at least a portion of the proximal segment and/or distal segment comprises an outer layer (e.g., outer tube) that is attached to an inner layer (e.g., inner tube) and a wall of at least a portion of the distensible segment comprises an outer layer (e.g., outer tube) that is not attached to an inner layer (e.g., inner tube); iv) wherein the distensible segment and proximal segment comprise a plurality of ribs (e.g., coils forming a portion of the wall of the catheter) spaced apart and further wherein the spacing between at least some of the adjacent ribs in the distensible segment but not in the proximal segment is configured to increase when the catheter open distal end becomes lodged against a wall of a blood vessel and the catheter is pushed proximally; v) wherein the distal segment comprises a metallic band; and/or vi) wherein the distensible segment has a variable height, width, length and/or shape and the proximal segment and the distal segment have a fixed height, width, length and/or shape. Optionally, the catheter includes one or more features described above. Optionally, the catheter is used in one or more of the methods described above.

DETAILED DESCRIPTION

Referring toFIGS.5-28, in some embodiments, the present disclosure provides a catheter, generally designated by the numeral10.FIGS.12-16are drawn to scale,FIGS.17-19are drawn to scale lengthwise,FIGS.4-11and20-28are not drawn to scale. It will be appreciated that the proportional dimensions provided inFIGS.12-19are exemplary and that other dimensions are possible.

The catheters of the present disclosure10are preferably specifically designed to avoid the aforementioned ledge16effect and access a human blood vessel105distal to the ophthalmic artery18, as shown inFIGS.11A and11Bfor example. For example, in some embodiments, the catheter10may be used as an aspiration catheter or a distal access catheter. More particularly, in some embodiments, as shown inFIG.11A, if the catheter10is used as a distal access catheter, a microcatheter106or other neurovascular device may be moved through the lumen/hollow interior34of the catheter10to, for example, access a human blood vessel105distal to the ophthalmic artery18. If the catheter10is used as an aspiration catheter, as shown inFIG.11B, the catheter proximal end22may be configured to couple to a suction source, such as a pump or syringe (not shown), via a tapered hub78, for example, and the suction source may be configured to draw a clot104or other object located distal to the catheter's distal end64toward the catheter distal end12(and optionally into the catheter distal end12and proximally within the catheter interior towards the suction source).

With reference toFIGS.5-28, in some embodiments, the present disclosure provides a catheter10that, like a typical catheter, may include an interior/lumen34(which may be hollow), a catheter proximal end22that may be open and lead to the interior34, a catheter distal end12that may be open and lead to the interior34, a length extending from the catheter proximal end22to the catheter distal end12, and a width32perpendicular to the length28and a height30perpendicular to the width32and length28.

Unlike typical catheters, in some embodiments, the catheter10is comprised of at least one segment, i.e., a distensible segment50, that is located between a proximal segment36and a distal segment64, that is designed differently from the proximal segment36and the distal segment64, and is designed to behave differently than proximal segment36and the distal segment64when the catheter open distal end12becomes lodged against a vessel wall14(e.g., where the ophthalmic artery18branches away from the internal carotid artery20) and the surgeon is pushing the catheter10distally through a blood vessel. More particularly, the catheter10may comprise a relaxed configuration in which the proximal segment36, distal segment64and distensible segment50are cylindrical in shape and comprise an inner diameter48,76and62, respectively, of from about 0.04 inches to about 0.10 inches. Preferably, as shown inFIGS.5-6, the top drawing inFIG.7A, andFIG.8in the relaxed configuration, the proximal, distal and distensible segments36,64and50comprise inner diameters that are substantially equal to each other and outer diameters that are substantially equal to each other (i.e., catheter10has a substantially uniform inner diameter100and a substantially uniform outer diameter102throughout the catheter length28). However, as shown inFIG.7, the bottom two drawings inFIG.7A,FIG.9,FIG.10andFIG.10A, when a surgeon attempts to push the catheters of the present disclosure distally in a blood vessel when the catheter open distal end12is lodged against a vessel wall14(i.e., when a linear force in the distal direction is applied to the proximal segment36and, in response, a linear force in the proximal direction is applied to the catheter open distal end12), the catheter10is configured to self-adjust/transition from the relaxed configuration to a distended configuration in which i) the cross-sectional height and/or width of the distensible segment50is configured to increase, the distensible segment50is configured to become non-cylindrical, and/or at least one side of the catheter10in the distensible segment50is configured to bulge outward, and ii) the cross-sectional width, cross-sectional height and length of the proximal segment36and the distal segment64are configured to remain constant and the proximal segment36and the distal segment64are configured to remain cylindrical, in order to dislodge the catheter open distal end12from the vessel wall14. Stated otherwise, when a surgeon pushes a prior art catheter10′ in the distal direction when the catheter open distal end12′ is lodged against the vessel wall14′, a proximal portion of the prior art catheter10′ kinks (as shown inFIG.4), because the vessel wall14′ exerts a force in the proximal direction against the catheter open distal end12. In contrast, when a surgeon pushes the catheters10of the present disclosure in the distal direction when the catheter open distal end12is lodged against the vessel wall14, the proximal portion of the catheter10does not kink but instead the distensible segment50of the catheter10preferably undergoes a conformational change allowing the catheter open distal end12to dislodge from the vessel wall14, as shown inFIG.9,FIG.10andFIG.10A.

Once the catheter open distal end12is dislodged from the open vessel wall14, the catheter10preferably returns to the relaxed configuration, as shown inFIG.11. In other words, optionally, as shown inFIG.11, the catheter10is configured to self-adjust/transition from the distended configuration to the relaxed configuration when a linear force in the proximal direction ceases being applied to the catheter open distal end12(because the catheter open distal end12is dislodged).

For example, in an in vitro flow model designed to mimic the branching of the ophthalmic artery18from the internal carotid artery20, which is shown inFIGS.1-4,10and10A, catheters10designed and assembled as shown inFIGS.12-28were seen to self-adjust/transition from the relaxed configuration to the distended configuration shown inFIG.10or the distended configuration shown inFIG.10A, both of which allowed the catheter10to dislodge from the vessel wall14, then return to the relaxed configuration and advance in the internal carotid artery20distally beyond the site of the branching of the ophthalmic artery18, as shown inFIG.11. By comparison, when the CAT6 Distal Access Catheter (Stryker) was used in the same flow model, it was not able to dislodge from the vessel wall14and it was not able to advance in the internal carotid artery20distally beyond the site of the branching of the ophthalmic artery18.

In some embodiments, the proximal segment36of the catheter10comprises a proximal segment proximal end38, a proximal segment distal end40located proximal to the catheter open distal end12, a proximal segment length42extending from the proximal segment proximal end38to the proximal segment distal end40and parallel to the catheter length28, a proximal segment width44parallel to the catheter width32, and a proximal segment height46parallel to the catheter height30. As mentioned previously, the proximal segment36is preferably cylindrical in both the relaxed configuration and distended configuration so that the height46and width44are the merely the outer diameter88of the proximal segment36.

In some embodiments, the distensible segment50comprises a proximal end52located distal to the proximal segment distal end40, a distensible segment distal end54located proximal to the catheter open distal end12, a distensible segment length56extending from the distensible segment proximal end52to the distensible segment distal end54and parallel to the catheter length28, a distensible segment width58parallel to the catheter width32, and a distensible segment height60parallel to the catheter height30. As mentioned previously, the distensible segment50is preferably cylindrical in the relaxed configuration so that the height60and width58in the relaxed configuration are the merely the outer diameter90of the distensible segment50.

In some embodiments, the distal segment64comprise a distal segment proximal end66located distal to the distensible segment distal end54, a distal segment distal end68, a distal segment length70extending from the distal segment proximal end66to the distal segment distal end68and parallel to the catheter length28, a distal segment width72parallel to the catheter width32, and a distal segment height74parallel to the catheter height30. As mentioned previously, the distal segment64is preferably cylindrical in both the relaxed configuration and distended configuration so that the height74and width72are merely the outer diameter of the distal segment64.

Optionally, the length of the catheter10is from about 100 centimeters to about 165 centimeters.

Optionally, in the distended configuration, the length of the distensible segment50is configured to decrease, as shown by comparingFIG.7withFIG.6and as shown by comparing the bottom drawings inFIG.7Awith the top drawing inFIG.7A.

Optionally, in the distended configuration, the distensible segment50is a non-cylindrical shape (e.g., both sides of the distensible segment50may bulge outward as shown inFIGS.7and7AandFIG.10, one side may bulge outward to a greater degree than an opposite side of the catheter10or one side of the distensible segment50may shorten and curve inward and an opposite side may lengthen and bulge outward, as shown inFIG.10A).

Optionally, the length of the distensible segment50is from about 5 millimeters to about 10 millimeters. Optionally, the length42of the proximal segment36is greater than the length70of the distal segment64. For example, optionally, the length42of the proximal segment36is at least ten times greater than the length56of the distensible segment50and the length70of the distal segment64. Optionally, the length56of the distensible segment50is greater than the length70of the distal segment64.

Optionally, the distal end68of the distensible segment50is located about 0.5 millimeters to about 5 millimeters from the catheter open distal end12(e.g., preferably about 1.5 mm from the catheter open distal end12).

Optionally, the catheter proximal end22is coupled to a suction source (not shown). Optionally, the catheter proximal end22comprises a hub78that may be tapered, shown inFIG.11B, to allow the catheter proximal end22to be coupled to a suction source. Optionally, the suction source is a syringe or pump. Suction sources for aspiration catheters are well known and an example includes the PENUMBRA ENGINE aspiration source, which is said to deliver and maintain nearly pure vacuum (−29.2 inHg or 98.9 kPa).

Optionally, as shown inFIGS.7A-28, the distal segment64comprises a cylindrical metallic band80located distal to the distensible segment distal end54and adjacent to the catheter distal end12. Optionally, the cylindrical metallic band80is located from about 0 millimeters to about 5 millimeters distal to the distensible segment distal end54(e.g., about 1-2 mm). Optionally, the cylindrical metallic band80is located at or adjacent the catheter open distal end12, e.g., from about 0 millimeters to about 5 millimeters proximal to the catheter open distal end12(e.g., about 1-2 mm).

Optionally, the cylindrical metallic band80comprises a length82parallel to the catheter length28and optionally the length82of the cylindrical metallic band80is less than the length56of the distensible segment50. For example, in a non-limiting example, the cylindrical metallic band80has a length82of from about 0.02 inches to about 0.10 inches (e.g., about 0.03-0.06 inches), an inner diameter84of from about 0.04 inches to about 0.10 inches and an outer diameter86of from about 0.05 inches to about 0.10 inches. Optionally, the cylindrical metallic band80serves as an x-ray marker and is more visible under x-ray as compared to the distensible segment50when the catheter10is located in a cranial blood vessel inside the body of a human and the x-ray is taken from outside the human's body. Optionally, the cylindrical metallic band80is comprised of tantalum, platinum and/or iridium. In the embodiments shown inFIGS.8-28, in addition to serving as x-ray marker, the cylindrical metallic band80makes the distal segment64stiff and prevents the distal segment64from shortening and widening in the distended configuration. Optionally, the cylindrical metallic band80, the proximal segment36and the distensible segment50have substantially the same size inner diameters in the relaxed configuration. Optionally, the cylindrical metallic band80, the proximal segment36and the distensible segment50have substantially the same size outer diameters in the relaxed configuration. Optionally, the cylindrical metallic band80is rigid. Optionally, because the cylindrical metallic band80is rigid, the distal segment64is rigid.

Optionally, the distal segment64extends from the distensible segment distal end54to the catheter open distal end12.

Optionally, the braid98, coil96, outer tube95, and/or inner tube94extend substantially the full length of the catheter10(e.g., at least 90% of the full length of the catheter10). For example, the distal end of the coil96may be located under the cylindrical metallic band80.

Optionally, the proximal segment36extends from the catheter proximal end22to the distensible segment proximal end52.

Optionally, the catheter10further comprises a wall92extending from at least the proximal segment36to the distal segment64(and preferably from the catheter proximal end22to the catheter open distal end12). Optionally, the wall92is comprised of an inner tube94surrounding the hollow interior34and an outer tube95extending around the inner tube94. A detailed view of the outer tube95is shown inFIG.17and a detailed view of the inner tube94is shown inFIG.18. Optionally, each of the outer tube95and inner tube94are comprised of an elastomeric material (e.g., polyurethane). Optionally, as shown inFIG.17, the outer tube95is comprised of a plurality of different segments/cylinders95a-95j(ten segments/cylinders in the illustrated embodiment ofFIG.17, with the longest segment/cylinder95abeing the proximal segment/cylinders, which has a length of 105 centimeters, and the remaining segments/cylinders95b-95jhaving a length of between 3-4 centimeters) that are joined and the flexibility of the segments increases moving distally along the length of the outer tube95. InFIG.18, the inner tube94is comprised of a proximal segment/cylinder94ahaving a length of 123 centimeters and a second segment94bhaving a length of 17.5 centimeters with 0.5 centimeters of overlap206between the segments94aand94b. It will be understood that all dimensions are exemplary.

Optionally, the outer tube95is attached to the inner tube94in the proximal distal36and in the distal segment64. By contrast, optionally, the outer tube95is not attached to the inner tube94for at least a portion of the distensible segment50. A catheter10comprising these characteristics is shown in the stepwise manufacturing method shown inFIGS.17-28. It will be understood the manufacturing process illustrated is exemplary and other methods may be used. Optionally the wall further comprises a coil96, braid98, and the aforementioned cylindrical metallic band80, as described below.

For example,FIGS.12-13respectively show an exploded view and an assembled view of a coil96, metallic band and braid98of a catheter10of an embodiment of the present invention. InFIG.12-13, the inner and outer tubes94and95are not shown for simplicity. The coil96extends around the inner tube94in a helical manner and as shown inFIGS.12-16, and19-28the pitch of the coil96is not uniform throughout the catheter length28, but rather one segment of the coil96has an increased coil pitch (segment labelled as103) as compared to another segment (segment labelled as99) of the coil96. More particularly, the pitch of the coil96in the distensible segment50is greater than the pitch of the coil96in the proximal segment36. In other words, segment99corresponds to the pitch of the coil96located in the proximal segment36and segment103corresponds to the pitch of the coil96located in the distensible segment50. The increased pitch/spacing between adjacent strands of the coil96in the distensible segment50(together with the fact that, as mentioned above, the outer tube95is preferably not attached to the inner tube94for at least a portion of the distensible segment50) allows the distensible segment50to self-adjust to the distended configuration while the shape and size of the proximal and distal segments36and64remains fixed. Optionally, the coil96pitch in the distensible segment50is between about 0.006 inches to 0.040 inches and optionally the coil96pitch in the proximal segment36is between about 0.002 to about 0.006 inches. More preferably, the coil96pitch in the distensible segment50is between about 0.015 inches to 0.040 inches and optionally, the coil96pitch in the proximal segment36is between about 0.002 inches to about 0.006 inches. For example, in the illustrated embodiment, the pitch of the coil96in the proximal segment36is 0.004 inches to 0.006 inches and the coil96pitch of the distensible segment50is 0.20 inches. Accordingly, optionally, the pitch of the coil96in the distensible segment50is at least three times the pitch of the coil96in the proximal segment36. Optionally, the pitch of the coil96in the distal segment64(under the metallic band80) is the same as the pitch of the coil96in the distensible segment50, however, the presence of the metallic band80in the distal segment64provides rigidity to the distal segment64so that its shape and size remain fixed. In addition, optionally, the coil96pitch in the proximal segment36increases (e.g., from 0.004 to 0.006 inches) as the coil96approaches the proximal end52of the distensible segment50.

Referring further to the exemplary manufacturing process,FIG.19illustrates a detailed view of the coil96, braid98and cylindrical metallic ring80. It will be understood that all dimensions are exemplary.FIG.20illustrates a view of the inner tube94, which is formed by joining a segment/cylinder comprised of PTFE and with a segment/cylinder comprised of PEBAX 25D with EVERGLIDE. As mentioned above, there is 0.5 centimeter overlap206in the segments/cylinders. InFIG.20, the wall thickness205of the inner tube94is 0.001 inches.FIG.21shows how the PTFE and PEBAX segments fuse together at overlap206.FIG.22illustrates how a coil96with a non-uniform pitch is positioned over the inner tube94ofFIG.21. In FIG.22, the coil has a diameter of 0.0015 inches.FIG.23illustrates how the distensible segment50of the coil96(which has the greatest pitch) is fused to the PTFE segment but the proximal segment36of the coil96is not fused.FIG.24illustrates how a braid98(e.g., 16 wire, 0.001×0.003 inch rectangular wire) is positioned over the coil96.FIG.25illustrates tack welding of the braid98and coil96as shown by numeral202.FIG.26illustrates gluing of the metallic band to the braid98.FIG.27illustrates positioning the outer tube95over the metallic band, braid98, coil96and inner tube94.FIG.28illustrates fusing the outer tube95, braid98, coil96, and inner tube94in the proximal segment36and in the distal segment64but not in at least a portion200of the distensible segment50. (InFIG.28, the aforementioned portion200is the entire distensible segment50). This site-specific attachment of the outer tube95results in a configuration in which for at least a portion200of the distensible segment50, the coil96is attached to the inner tube94but not to the outer tube95, and in which, in the proximal segment36and the distal segment64, the coil96is attached to the inner tube94and the outer tube95. Optionally, the catheter10is completely built but left on the mandrel (i.e.,FIGS.20-28take place on a mandrel) and the catheter10is coated with a hydrophilic coating to give the catheter10lubricity. After coating, tip trimming is performed (cut catheter10tip to 1 mm), mandrel removal (remove the build mandrel), hub bonding (cut catheter10to length and add hub78to proximal end of catheter10), and packaging. Post packaging is sterilization (EtO—ethylene oxide).

Optionally, as mentioned above, the catheter10is coated with a hydrophilic coating.

Optionally, for at least a portion of the distensible segment50, the braid98is attached to the inner tube94but not to the outer tube95, and further wherein, in the proximal segment36and the distal segment64, the braid98is attached to the inner tube94and the outer tube95.

Optionally, in the relaxed configuration, the catheter10comprises a substantially constant inner diameter100and a substantially constant outer diameter102along the catheter length28. For example, in the relaxed configuration, the catheter10comprises an inner diameter100of from about 0.06 to about 0.08 inches and an outer diameter102of from about 0.08 to about 0.1 inches.

Optionally, though not shown, the catheter10comprises a plurality of distensible segments (each of which are configured to undergo a conformational change), in which case the catheter may be comprised of a proximal segment located proximal to the distensible segments50, a distal segment located distal to the distensible segments50, and one or more intermediary segments, with an intermediary segment between each distensible segment and each intermediary segment having the same characteristics as the proximal and distal segments—i.e., a fixed cylindrical shape, outer diameter and length.

Optionally, the catheter10is designed to be used in humans—i.e., comprised of a biocompatible material and is sterile.

Optionally, the catheter10is used in a method comprising providing the catheter10, inserting the catheter open distal end12into a human blood vessel and moving the catheter open distal end12distally in the human blood vessel. Optionally, the human blood vessel comprises a clot104, the catheter proximal end22is coupled to a suction source, and the method further comprises using suction to draw the clot104toward the catheter distal end12to remove the clot104from the human blood vessel. Optionally, the method further comprises using a stent retriever in conjunction with the catheter10to remove the clot104from the human blood vessel. Optionally, the method comprises pushing the catheter10distally, allowing the catheter open distal end12to contact and become stuck against a wall14of the human blood vessel (e.g., at ledge of18and20), and continuing to push the catheter10distally so that the catheter open distal end12moves towards a center of the human blood vessel to become dislodged from the vessel wall14. Optionally, prior to the catheter open distal end12becoming dislodged from the vessel wall14, i) the height60and/or width58of the distensible segment50increases, the distensible segment50becomes non-cylindrical, and/or at least one side of the catheter10bulges outward, and ii) the heights46/74, widths72/44and lengths42and70of the proximal and distal segments36and64stay constant and the proximal and distal segments36and64remain cylindrical. Optionally, prior to the catheter open distal end12moving towards the center of the human blood vessel to become dislodged from the vessel wall14, the distensible segment50moves away from the vessel wall14then towards the vessel wall14to cause the catheter open distal end12to move towards the center of the human blood vessel to become dislodged from the vessel wall14. Optionally, the human blood vessel is the internal carotid artery20. Optionally, the method further comprises moving a microcatheter106or other neurovascular device through the hollow interior34(e.g., to access a vessel distal to where the ophthalmic artery18branches from the internal carotid artery).

Optionally, the aforementioned method does not include placing the catheter10through a guide wire—i.e., that the catheter10self-adjusts without a guide wire. Optionally, the catheter10is used in a method that comprises inserting the catheter distal end12into a human, passing the catheter distal end12beyond the turns of the cavernous sinus and petrous bone and optionally applying suction to draw a clot104or other object into the catheter distal end12.

Optionally, the catheter10is used in conjunction with a stent retriever for retrieving a clot104. Stent retrievers are described in, for example, U.S. patent application Ser. No. 17/741,673, the entire contents of which are incorporated herein by reference.

Part ListCatheter10Catheter distal end12Vessel wall14Ledge16Ophthalmic artery18Internal carotid artery20Catheter proximal end22Catheter length28Catheter height30Catheter width32Catheter interior/lumen34Proximal segment36Proximal segment proximal end38Proximal segment distal end40Proximal segment length42Proximal segment width44Proximal segment height46Proximal segment inner diameter48Distensible segment50Distensible segment proximal end52Distensible segment distal end54Distensible segment length56Distensible segment width58Distensible segment height60Distensible segment inner diameter62Distal segment64Distal segment proximal end66Distal segment distal end68Distal segment length70Distal segment width72Distal segment height74Distal segment inner diameter76Proximal hub78Cylindrical metallic band80Cylindrical metallic band length82Cylindrical band inner diameter84Cylindrical band outer diameter86Proximal segment outer diameter88Distensible segment outer diameter90Catheter wall92Inner tube94Outer tube95Coil96Braid98Segment with smaller coil pitch99Catheter inner diameter100Catheter outer diameter102Segment with larger coil pitch103Clot104Distal vessel105Microcatheter106Unbounded area200Tack weld202Overlap between two segments of206inner tube

Those skilled in the art will understand how to make changes and modifications to the disclosed embodiments to meet their specific requirements or conditions. Changes and modifications may be made without departing from the scope and spirit of the invention. It is understood that use of the singular embraces the plural and vice versa. In addition, the steps of any method described herein may be performed in any suitable order and steps may be performed simultaneously if needed.

Terms of degree such as “generally”, “substantially”, “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. For example, these terms can be construed as including a deviation of at least ±5% of the modified term if this deviation would not negate the meaning of the word it modifies. In addition, the steps of the methods described herein can be performed in any suitable order, including simultaneously.