Subintimal reentry catheter with intravascular ultrasound function

Abstract

A recanalization catheter is provided that facilitates reentry from a subintimal space in a vessel wall into a lumen having an occlusion therein of the vessel. The recanalization catheter includes a catheter shaft extending distally from a hub. The catheter shaft defines a guidewire lumen extending therethrough. A first inflatable balloon member and a second inflatable balloon member are disposed on a distal end region of the catheter shaft. The catheter shaft includes an inflation lumen in fluid communication with the first and second inflatable balloon members. A lateral opening in communication with the guidewire lumen leads to an exterior of the catheter shaft between the first and second inflatable balloon members on a first side of the catheter shaft. The catheter shaft also includes an imaging lumen extending through the catheter shaft that is configured to receive an IVUS imaging device therein.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 451,372, filed on March 10, 2023, which is incorporated herein by reference. Technical Field

[0003] The present invention relates to devices and methods for recanalizing occluded blood vessels. More particularly, the present invention relates to devices and methods for re-entering the true lumen from the extraluminal or subintimal space of a blood vessel. Background Art

[0004] Chronic total occlusion (CTO) refers to an arterial vascular occlusion that obstructs blood flow through the blood vessel and can occur in both the coronary arteries and peripheral arteries. In some cases, it may be difficult or impossible to pass through the CTO in the antegrade direction with a medical device to achieve recanalization of the vessel. Therefore, a technique has been developed for creating a subintimal path (i.e., a path between the intima and adventitia tissue layers of the vessel) around the occlusion and subsequently reentering the true lumen of the vessel distal to the occlusion to achieve recanalization of the vessel. In some cases, it may be difficult to reenter the true lumen and / or achieve recanalization from the subintimal space using only angiographic techniques. Therefore, it is necessary to provide an alternative recanalization device with integrated intravascular ultrasound (IVUS) to achieve real-time imaging and / or associated methods for achieving recanalization of a vessel in which a CTO is present during subintimal advancement and reentry. Summary of the Invention

[0005] The present invention relates to several alternative designs, materials and methods of making medical device structures and components, and their uses.

[0006] Thus, an illustrative example is a recanalization catheter for facilitating reentry from the subintimal space in the vessel wall into a lumen having an occluded blood vessel. The recanalization catheter includes a catheter shaft extending distally from a hub. The catheter shaft defines a guidewire lumen extending therethrough. A first inflatable balloon member and a second inflatable balloon member are disposed on a distal region of the catheter shaft. The catheter shaft includes an inflation lumen in fluid communication with the first inflatable balloon member and the second inflatable balloon member. A lateral opening in communication with the guidewire lumen leads to an exterior of the catheter shaft between the first inflatable balloon member and the second inflatable balloon member on a first side of the catheter shaft. The catheter shaft also includes an imaging lumen extending therethrough that is configured to receive an IVUS imaging device therein.

[0007] Additionally or alternatively to any examples disclosed herein, the inflation lumen includes a first inflation lumen in fluid communication with the first inflatable balloon member, and a second inflation lumen in fluid communication with the second inflatable balloon member.

[0008] Additionally or alternatively to any of the examples disclosed herein, in the proximal portion of the catheter shaft, the central longitudinal axis of the catheter shaft passes through the imaging lumen, and all of each of the first inflation lumen, the second inflation lumen, and the guidewire lumen are positioned on a first side of a first imaginary plane that extends parallel to the central longitudinal axis and passes through the central longitudinal axis.

[0009] Additionally or alternatively to any of the examples disclosed herein, in the distal portion of the catheter shaft, the imaging lumen and the guidewire lumen are positioned between the first inflation lumen and the second inflation lumen, with a second imaginary plane passing through each of the first inflation lumen, the second inflation lumen, the imaging lumen, and the guidewire lumen, the second imaginary plane extending parallel to the central longitudinal axis and passing through the central longitudinal axis.

[0010] Additionally or alternatively to any of the examples disclosed herein, the proximal portion of the catheter shaft has a circular cross-sectional shape, and the distal portion of the catheter shaft has a generally rectangular cross-sectional shape.

[0011] Additionally or alternatively to any of the examples disclosed herein, the first inflatable balloon member and the second inflatable balloon member are configured to be inflated laterally from opposite sides of the catheter shaft along a third imaginary plane, with the third imaginary plane passing through each of the imaging lumen and the guidewire lumen.

[0012] Additionally or alternatively to any of the examples disclosed herein, the recanalization catheter further comprises an IVUS imaging device positionable within the imaging lumen to position an IVUS transducer distally of the first lateral opening.

[0013] Additionally or alternatively to any of the examples disclosed herein, the catheter shaft has an outer diameter of 0.059 inches or less, the guidewire lumen has a diameter of about 0.017 inches, and a minimum distance across the imaging lumen by a central axis of the imaging lumen is 0.033 inches or more.

[0014] Additionally or alternatively to any of the examples disclosed herein, the catheter shaft has an outer diameter of 0.052 inches or less, the guidewire lumen has a diameter of about 0.017 inches, and a minimum distance across the imaging lumen by a central axis of the imaging lumen is 0.026 inches or more.

[0015] Additionally or alternatively to any of the examples disclosed herein, the catheter shaft has a wall thickness of at least 0.003 inches at all locations along the catheter shaft.

[0016] Another example is a recanalization catheter that facilitates recanalization of a lumen of a blood vessel having an occlusion therein from a subintimal space in a wall of the blood vessel. The recanalization catheter includes a catheter shaft extending distally from a hub and an expandable balloon disposed on a distal end region of the catheter shaft. The catheter shaft is an extruded tubular member that defines a guide wire lumen extending therethrough, an inflation lumen in fluid communication with an interior of the expandable balloon, and an imaging lumen extending through the catheter shaft, the imaging lumen configured to receive an IVUS imaging device therein.

[0017] Additionally or alternatively for any of the examples disclosed herein, the recanalization catheter further includes an IVUS imaging device positionable within the imaging lumen such that an IVUS transducer of the IVUS imaging device is distal of the expandable balloon.

[0018] Additionally or alternatively for any of the examples disclosed herein, the recanalization catheter further includes a lateral opening in communication with the guide wire lumen. The lateral opening opens to an exterior of the catheter shaft between a proximal end of the expandable balloon and a distal end of the expandable balloon.

[0019] Additionally or alternatively for any of the examples disclosed herein, the inflation lumen includes a first inflation lumen in fluid communication with a first inflatable balloon member of the expandable balloon and a second inflation lumen in fluid communication with a second inflatable balloon member of the expandable balloon. In a proximal portion of the catheter shaft, a central longitudinal axis of the catheter shaft passes through the imaging lumen and all of each of the first inflation lumen, the second inflation lumen, and the guide wire lumen are positioned on a first side of a first imaginary plane, the first imaginary plane extending parallel to and passing through the central longitudinal axis.

[0020] Additionally or alternatively for any of the examples disclosed herein, in a distal portion of the catheter shaft, the imaging lumen and the guide wire lumen are positioned between the first inflation lumen and the second inflation lumen such that a second imaginary plane passes through each of the first inflation lumen, the second inflation lumen, the imaging lumen, and the guide wire lumen, the second imaginary plane extending parallel to and passing through the central longitudinal axis.

[0021] Yet another example is a recanalization catheter that facilitates recanalization of a lumen of a blood vessel having an occlusion therein from a subintimal space in a blood vessel wall. The recanalization catheter includes a catheter shaft extending distally from a hub and an expandable balloon disposed on a distal end region of the catheter shaft, the expandable balloon including a first inflatable balloon member on a first side of the catheter shaft and a second inflatable balloon member on a second side of the catheter shaft opposite the first side. The catheter shaft includes an extruded proximal tubular member having a circular cross-sectional shape and an extruded distal tubular member having a generally rectangular cross-sectional shape. The catheter shaft defines a guidewire lumen extending through the extruded proximal tubular member and the extruded distal tubular member, a first inflation lumen extending through the extruded proximal tubular member and the extruded distal tubular member, a second inflation lumen extending through the extruded proximal tubular member and the extruded distal tubular member, and an imaging lumen extending through the extruded proximal tubular member and the extruded distal tubular member. The first inflation lumen is in fluid communication with an interior of the first inflatable balloon member and the second inflation lumen is in fluid communication with an interior of the second inflatable balloon member. The imaging lumen is configured to receive an IVUS imaging device therein.

[0022] Additionally or alternatively for any of the examples disclosed herein, the recanalization catheter further includes a lateral opening in communication with the guidewire lumen. The lateral opening opens to an exterior of the catheter shaft between the first inflatable balloon member and the second inflatable balloon member.

[0023] Additionally or alternatively for any of the examples disclosed herein, the recanalization catheter further includes an IVUS imaging device positionable within the imaging lumen such that an IVUS transducer of the IVUS imaging device is distal of the lateral opening, preferably distal of the expandable balloon.

[0024] Additionally or alternatively for any of the examples disclosed herein, throughout the extruded proximal tubular member, a central longitudinal axis of the catheter shaft passes through the imaging lumen and all of each of the first inflation lumen, the second inflation lumen, and the guidewire lumen are positioned on a first side of a first imaginary plane that extends parallel to and passes through the central longitudinal axis.

[0025] Additionally or alternatively for any of the examples disclosed herein, throughout the extruded distal tubular member, the imaging lumen and the guidewire lumen are positioned between the first inflation lumen and the second inflation lumen such that a second imaginary plane passes through each of the first inflation lumen, the second inflation lumen, the imaging lumen, and the guidewire lumen, the second imaginary plane extending parallel to and passing through the central longitudinal axis.

[0026] Yet another example is a catheter that facilitates recanalization of a lumen of a blood vessel having an occlusion therein from a subintimal space in a wall of the blood vessel. The catheter can include an elongate catheter shaft having a guidewire lumen and an imaging lumen extending therethrough. A distal end region of the catheter shaft can include a lateral opening in communication with the guidewire lumen. The catheter shaft can include a reinforcing structure, such as a braid or coil, to facilitate torque transmission of the catheter shaft such that the lateral opening can be rotationally oriented toward a true lumen of the blood vessel located distal of the occlusion. A recanalization device can be advanced through the guidewire lumen and pushed out of the lateral opening to recanalize the true lumen located distal of the occlusion. The imaging lumen is configured to receive an IVUS imaging device therein. The IVUS imaging device is configured to provide ultrasound images of the blood vessel to confirm the rotational orientation of the lateral opening in the subintimal space and / or the trajectory of the recanalization device from the lateral opening toward the true lumen.

[0027] The above summary of some example embodiments is not intended to describe each disclosed embodiment or every implementation of the aspects of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0028] Various aspects of the application can be more fully understood from the following detailed description, taken in connection with the accompanying drawings, in which:

[0029] Figure 1 is a perspective view of an example catheter for vascular recanalization;

[0030] Figure 2A is a cross-sectional view of the catheter shaft of the catheter of Figure 1

[0031] Figure 2B is an alternative cross-sectional view of the catheter shaft of the catheter of Figure 1

[0032] Figure 2C is an alternative cross-sectional view of the catheter shaft of the catheter of Figure 1

[0033] Figure 2D is an alternative cross-sectional view of the catheter shaft of the catheter of Figure 1

[0034] Figure 3 is a cross-sectional view of the catheter shaft of the catheter of Figure 1

[0035] Figure 4 is a cross-sectional view of the catheter shaft of the catheter of Figure 1

[0036] Figure 5 is a cross-sectional view of the catheter shaft of the catheter of Figure 1 ​​​​​​longitudinal cross-sectional view of a distal region of the catheter;

[0037] Figures 6-10 Aspects of an exemplary method of achieving recanalization of an occluded blood vessel using the catheter of Figure 1

[0038] Figure 11 is a plan view of an exemplary catheter for recanalization of a blood vessel;

[0039] Figure 12 is a cross-sectional view of the catheter shaft of the catheter of Figure 11 Figure 11

[0040] While aspects of the application are amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in greater detail below. It should be understood, however, that the intention is not to limit aspects of the application to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the application. DETAILED DESCRIPTION

[0041] For the following defined terms, these definitions shall be applied even if occurring in the claims or elsewhere in the application.

[0042] All numerical values are assumed to be modified by the term "about," whether or not explicitly indicated by the term "about." The term "about" generally refers to a range of numbers that one of skill in the art would consider equivalent to the referenced number (i.e., having the same function or result). In many instances, the term "about" can indicate numbers that include a rounding off, based on the standard of rounding off used by one of ordinary skill in the art to which the application pertains.

[0043] Ranges of values of numerals that are recited as being suitable include all values from the lower value and up to the upper value, inclusive of the integers within that range. Thus, a range of "1 to 5" includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5.

[0044] While some suitable dimensions, ranges, and / or values are disclosed regarding various components, characteristics, and / or specifications, those skilled in the art in light of the present disclosure will appreciate that expected dimensions, ranges, and / or values can deviate from those explicitly disclosed.

[0045] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally employed in its sense of "and / or" unless the content clearly dictates otherwise.

[0046] ​​​The following detailed description should be read with reference to the drawings, in which like elements in different drawings are identically numbered. The detailed description and the drawings, which depict illustrative embodiments, are not intended to limit the scope of the present disclosure. The illustrative embodiments merely seek to describe illustrative embodiments. Selected features of any illustrative embodiment can be incorporated into additional embodiments unless clearly indicated otherwise.

[0047] Figure 1 An exemplary recanalization catheter 10 is shown in FIG. 1. The recanalization catheter 10 can include a catheter shaft 12 extending from a hub assembly 14 located at a proximal end 16 of the catheter shaft 12 to an expandable balloon 20 mounted on a distal end region 18 of the catheter shaft 12. The distal end region 18 of the catheter shaft 12 can extend through the expandable balloon 20 to form a distal tip 22 extending distally of the expandable balloon 20. As will be described further herein, in some cases, the expandable balloon 20 can be formed of one or more or multiple inflatable balloon members 20a, 20b that can be inflated with inflation fluid delivered through an inflation lumen 26 of the catheter shaft 12 (see Figures 2A-2D ), as described further herein.

[0048] The catheter 10 can be configured to be advanced over a guidewire to be delivered to a remote location in a patient’s vasculature. For example, in some cases, the catheter 10 can be configured as an over-the-wire (OTW) catheter having a guidewire lumen 24 extending through the entire length of the catheter 10 from a distal opening 28 located at the distal tip 22 of the catheter 10 to a proximal guidewire port 30 in the hub assembly 14 (see Figures 2A-2D ). The distal opening 28 can be located at the distal-most extent of the catheter 10. In other cases, the catheter 10 can be configured as a single operator exchange (SOE) catheter having a guidewire lumen 24 extending from the distal opening 28 to a proximal guidewire port (not shown) located a short distance proximal of the expandable balloon 20 and distal of the hub assembly 14. In such a configuration, the guidewire can extend through the guidewire lumen 24 between the distal opening 28 and the proximal guidewire port and along the exterior of the catheter shaft 12 proximal of the proximal guidewire port to the proximal end 16 of the catheter shaft 12. It should be noted that, in cases where the catheter 10 is a SOE catheter, the hub assembly 14 can not include the proximal guidewire port 30.

[0049] The recanalization catheter 10 can include and / or house an intravascular ultrasound (IVUS) imaging device 200. The IVUS imaging device 200 can include an elongated shaft 202 extending distally from a hub 202. In some instances, the IVUS imaging device 200 can also include a flushing port 206. The IVUS imaging device 200 can be coupled to, extend from, and / or be received by the port 36 such that the elongated shaft 202 of the IVUS imaging device 200 can be positioned through an imaging lumen (discussed below) of the catheter shaft 12.

[0050] Steering Figure 2A , which is along Figure 1 2-2, the catheter shaft 12 is a cross-sectional view of the catheter shaft 12. The catheter shaft 12, or a portion thereof, may be an extruded shaft having multiple lumens formed therein. For example, the proximal portion of the catheter shaft 12 may include a guidewire lumen 24, an inflation lumen 26 (shown as a bifurcated lumen including a first inflation lumen 26a and a second inflation lumen 26b, the second inflation lumen 26b extending parallel to and spaced apart from the first inflation lumen 26a), and one or more auxiliary lumens extending therethrough. For example, the catheter shaft 12 may include an imaging lumen 32 configured to accommodate an intravascular ultrasound (IVUS) device. The guidewire lumen 24 may extend to the distal tip 18 of the catheter shaft 12, while the inflation lumen 26 may extend from a proximal inflation port 34 in the hub assembly 14 to the interior of the expandable balloon 20. For example, the first inflation lumen 26a may be in fluid communication with the first inflatable balloon member 20a, and the second inflation lumen 26b may be in fluid communication with the second inflatable balloon member 20b. As the inflation lumen 26 extends to the proximal inflation port 34, the first inflation lumen 26a can merge with the second inflation lumen 26a. The imaging lumen 32 extends from the proximal port 36 through the catheter shaft 12 to the expandable balloon 20 and / or extends distally beyond the expandable balloon 20. In some cases, the imaging lumen 32 can extend to the distal tip 22, while in other cases, the imaging lumen 32 can terminate proximal to the distal tip 18 of the catheter shaft 12. For example, in some cases, the distal termination point of the imaging lumen 32 can be located along the longitudinal length of the expandable balloon 20.

[0051] like Figure 2A As shown, the proximal region of the catheter shaft 12 can have a circular cross-section with an outer diameter D1 of approximately 0.059 inches. In some cases, for example, the outer diameter D1 can be approximately 0.06 inches or less, approximately 0.055 inches or less, or approximately 0.052 inches or less. In some cases, for example, the outer diameter D1 can be approximately 0.059 inches, approximately 0.055 inches, approximately 0.052 inches, or approximately 0.050 inches. The outer diameter D1 can be sized so that the catheter shaft 12 of the catheter 10 can be attached to a capture balloon catheter such as the Trapper® sold by Boston Scientific Corporation. TMAn exchange device, for example having an outer diameter of approximately 0.026 inches, is positioned together in a 6F guide catheter having an inner lumen diameter of approximately 0.07 inches (such as in the range of approximately 0.070 inches to approximately 0.072 inches), in a 7F guide catheter having an inner lumen diameter of approximately 0.08 inches (such as in the range of approximately 0.078 inches to approximately 0.082 inches), or in an 8F guide catheter having an inner lumen diameter of approximately 0.09 inches (such as in the range of approximately 0.088 inches to approximately 0.091 inches).

[0052] The diameter D2 of the guidewire lumen 24 may be approximately 0.017 inches to accommodate a 0.014 inch guidewire. For example, the first inflation lumen 26a and the second inflation lumen 26b may each have a diameter D3 of approximately 0.0115 inches or less or approximately 0.0105 inches or less. The imaging lumen 32 may be sized to accommodate an IVUS device, such as the OptiCross® sold by Boston Scientific Corporation. TM The imaging catheter or its IVUS imaging core can also provide a space for fluid aspiration therethrough together with the IVUS imaging device. The elongated shaft 202 of the imaging device 200 is shown positioned within the imaging cavity 32. For example, in some cases, the outer diameter of the IVUS imaging device can be approximately 0.025 inches or less. Figure 2A As shown, where the outer diameter D1 is approximately 0.059 inches, the imaging cavity 32 can have a non-circular cross-section (which is shown as an elliptical cross-section) with a minor radius R1 of approximately 0.0165 inches and a major radius R2 of approximately 0.0212 inches, thereby providing the imaging cavity 32 with a distance across its minor axis of approximately 0.0330 inches, a distance across its major axis of approximately 0.0424 inches, an area of ​​approximately 0.00110 square inches, and a circumference of approximately 0.1189 inches. In other cases, such as when the outer diameter D1 is approximately 0.052 inches, the imaging lumen 32 can have an elliptical cross-section with a minor radius R1 of approximately 0.0130 inches and a major radius R2 of approximately 0.0175 inches, thereby providing the imaging lumen 32 with a distance across its minor axis of approximately 0.026 inches, a distance across its major axis of approximately 0.035 inches, an area of ​​approximately 0.0007147 square inches, and a circumference of approximately 0.09634 inches. The lumen can be sized such that the thickness T of the catheter wall is at least 0.003 inches at all locations on the catheter shaft 12. In other cases, for example, the lumen can be sized such that the thickness T of the catheter wall is at least 0.002 inches, at least 0.0024 inches, at least 0.0026 inches, or at least 0.0028 inches at all locations on the catheter shaft 12.

[0053] like Figure 2AAs shown, the cross-sectional area of ​​guidewire lumen 24 may be greater than the cross-sectional area of ​​each of first and second inflation lumens 26, 26, and the cross-sectional area of ​​imaging lumen 32 may be greater than the cross-sectional area of ​​guidewire lumen 24. However, other configurations are also contemplated.

[0054] In some cases, such as Figure 2A In the illustrated embodiment, the guidewire lumen 24 can be positioned between the first inflation lumen 26a and the second inflation lumen 26b. The guidewire lumen 24 can be equally spaced between the first inflation lumen 26a and the second inflation lumen 26b, with the wall thickness of the catheter shaft therebetween being approximately 0.002 inches or greater or approximately 0.003 inches or greater. Figure 2A As shown, the catheter shaft 12 can be configured such that each of the guidewire lumen 24, the first inflation lumen 26a, and the second inflation lumen 26b are positioned entirely on one side of a plane Y that is parallel to and passes through the central longitudinal axis X of the catheter shaft 12. The imaging lumen 32 can be positioned such that the central longitudinal axis X of the catheter shaft 12 is located within the imaging lumen 32, with the majority of the cross-sectional area of ​​the imaging lumen 32 being positioned on the opposite side of the plane Y that is parallel to and passes through the central longitudinal axis X.

[0055] In addition, if Figure 2B As shown, catheter shaft 12 can be configured such that plane Z, which extends parallel to and passes through central longitudinal axis X, passes through the center of each of guidewire lumen 24 and imaging lumen 32. In some cases, plane Z can be perpendicular to plane Y. First inflation lumen 26a can be positioned on a first side of plane Z, and second inflation lumen 26b can be positioned on a second side of plane Z. In some cases, first inflation lumen 26a and second inflation lumen 26b can be equidistantly spaced from plane Z.

[0056] Figure 1 Shown along Figure 2A An alternative cross-sectional view of the proximal portion of the catheter shaft 12 taken along line 2-2. The outer diameter D1 and the size, shape, configuration, and position of the guidewire lumen 24 and the first and second inflation lumens 26a, 26b may be the same as described above with respect to Figure 2B The imaging cavity 32 may be sized to accommodate an IVUS device, such as the OptiCross sold by Boston Scientific Corporation. TM The imaging catheter or its IVUS imaging core can also provide a space for fluid aspiration therethrough together with the IVUS imaging device. The elongated shaft 202 of the imaging device 200 is shown positioned within the imaging cavity 32. For example, in some cases, the outer diameter of the IVUS imaging device can be approximately 0.025 inches or less. Figure 2BAs shown, where the outer diameter D1 is approximately 0.059 inches, the imaging cavity 32 can have a non-circular cross-section (which is shown as an obround cross-section) with a minor radius R1 of approximately 0.0165 inches and a major radius R2 greater than 0.0212 inches, thereby providing the imaging cavity 32 with a distance across its minor axis of approximately 0.0330 inches, a distance across its major axis greater than 0.043 inches, an area of ​​approximately 0.00119 square inches, and a perimeter of approximately 0.1270 inches. In other cases, such as when the outer diameter D1 is approximately 0.052 inches, the imaging cavity 32 can have an obround cross-section with a minor radius R1 of approximately 0.0130 inches and a major radius R2 greater than 0.0175 inches, thereby providing the imaging cavity 32 with a distance across its minor axis of approximately 0.026 inches, a distance across its major axis greater than 0.035 inches, an area of ​​approximately 0.00081 square inches, and a perimeter of approximately 0.1064 inches. The lumen can be sized such that the catheter wall thickness T is at least 0.003 inches at all locations along the catheter shaft 12. In other cases, for example, the lumen can be sized such that the catheter wall thickness T is at least 0.002 inches, at least 0.0024 inches, at least 0.0026 inches, or at least 0.0028 inches at all locations along the catheter shaft 12.

[0057] like Figure 2B As shown, the cross-sectional area of ​​guidewire lumen 24 may be greater than the cross-sectional area of ​​each of first and second inflation lumens 26, 26, and the cross-sectional area of ​​imaging lumen 32 may be greater than the cross-sectional area of ​​guidewire lumen 24. However, other configurations are also contemplated.

[0058] like Figure 2C As shown, the catheter shaft 12 can be configured such that each of the guidewire lumen 24, the first inflation lumen 26a, and the second inflation lumen 26b are positioned entirely on one side of a plane Y that is parallel to and passes through the central longitudinal axis X of the catheter shaft 12. The imaging lumen 32 can be positioned such that the central longitudinal axis X of the catheter shaft 12 is located within the imaging lumen 32, with the majority of the cross-sectional area of ​​the imaging lumen 32 being positioned on the opposite side of the plane Y that is parallel to and passes through the central longitudinal axis X.

[0059] In addition, if Figure 1 As shown, catheter shaft 12 can be configured such that plane Z, which extends parallel to and passes through central longitudinal axis X, passes through the center of each of guidewire lumen 24 and imaging lumen 32. In some cases, plane Z can be perpendicular to plane Y. First inflation lumen 26a can be positioned on a first side of plane Z, and second inflation lumen 26b can be positioned on a second side of plane Z. In some cases, first inflation lumen 26a and second inflation lumen 26b can be equidistantly spaced from plane Z.

[0060] Figure 2C A cross-sectional view of a proximal portion of the catheter shaft 12 taken along line 2-2 is shown. Figure 2C The proximal region of the catheter shaft 12 can have a circular cross-section with an outer diameter D1 of, for example, about 0.052 inches. In some cases, the outer diameter D1 can be about 0.06 inches or less, about 0.055 inches or less, or about 0.052 inches or less, for example. In some cases, the outer diameter D1 can be about 0.059 inches, about 0.055 inches, about 0.052 inches, or about 0.050 inches, for example. The outer diameter D1 can be sized such that the catheter shaft 12 of the catheter 10 can be positioned within a 6F guide catheter having an inner lumen diameter of about 0.070 inches, along with a Trapper balloon catheter (such as the Trapper® catheter sold by Boston Scientific Corporation) having an outer diameter of about 0.026 inches, for example. The catheter shaft 12 can be positioned within a 7F guide catheter having an inner lumen diameter of about 0.078 inches, along with a Trapper balloon catheter having an outer diameter of about 0.026 inches, for example. The catheter shaft 12 can be positioned within an 8F guide catheter having an inner lumen diameter of about 0.088 inches, along with a Trapper balloon catheter having an outer diameter of about 0.026 inches, for example. TM The exchange device, for example, having an outer diameter of about 0.026 inches, can be positioned within a 6F guide catheter having an inner lumen diameter of about 0.070 inches, a 7F guide catheter having an inner lumen diameter of about 0.078 inches, or an 8F guide catheter having an inner lumen diameter of about 0.088 inches.

[0061] The guidewire lumen 24 can have a diameter D2 of about 0.017 inches to accommodate a 0.014 inch guidewire. The catheter shaft 12 can have a single inflation lumen 26, for example, having a diameter D3 of about 0.013 inches or less. The imaging lumen 32 can be sized to accommodate an IVUS device, such as the OptiCross® imaging catheter or IVUS imaging core sold by Boston Scientific Corporation, while also providing space for a fluid aspiration to be provided therethrough with the IVUS imaging device. The elongate shaft 202 of the imaging device 200 is shown positioned within the imaging lumen 32. In some cases, the outer diameter of the IVUS imaging device can be about 0.025 inches or less, for example. As shown, the imaging device 200 can be positioned within the imaging lumen 32 of the catheter shaft 12. TM The imaging catheter or IVUS imaging core thereof, while also providing space for a fluid aspiration to be provided therethrough with the IVUS imaging device. The elongate shaft 202 of the imaging device 200 is shown positioned within the imaging lumen 32. In some cases, the outer diameter of the IVUS imaging device can be about 0.025 inches or less, for example. As shown, the imaging device 200 can be positioned within the imaging lumen 32 of the catheter shaft 12. Figure 2CAs shown, where the outer diameter D1 is approximately 0.052 inches, the imaging cavity 32 can have an elliptical cross-section with a minor radius R1 of approximately 0.0125 inches and a major radius R2 of approximately 0.017 inches, thereby providing the imaging cavity 32 with a distance across its minor axis of approximately 0.025 inches, a distance across its major axis of approximately 0.034 inches, an area of ​​approximately 0.0006676 square inches, and a perimeter of approximately 0.09322 inches. In other cases, such as when the outer diameter D1 is approximately 0.059 inches, the imaging cavity 32 can have a non-circular cross-section (which is shown as an elliptical cross-section) with a minor radius R1 of approximately 0.0165 inches and a major radius R2 of approximately 0.0212 inches, thereby providing the imaging cavity 32 with a distance across its minor axis of approximately 0.0330 inches, a distance across its major axis of approximately 0.0424 inches, an area of ​​approximately 0.00110 square inches, and a perimeter of approximately 0.1189 inches. The lumen can be sized such that the catheter wall thickness T is at least 0.003 inches at all locations along the catheter shaft 12. In other cases, for example, the lumen can be sized such that the catheter wall thickness T is at least 0.002 inches, at least 0.0024 inches, at least 0.0026 inches, or at least 0.0028 inches at all locations along the catheter shaft 12.

[0062] like Figure 2D As shown, the cross-sectional area of ​​the guidewire lumen 24 may be greater than the cross-sectional area of ​​the inflation lumen 26, and the cross-sectional area of ​​the imaging lumen 32 may be greater than the cross-sectional area of ​​the guidewire lumen 24. However, other configurations are also contemplated.

[0063] like Figure 1 As shown, the catheter shaft 12 can be configured such that each of the guidewire lumen 24 and the inflation lumen 26 is positioned entirely on one side of a plane Y that is parallel to and passes through the central longitudinal axis X of the catheter shaft 12. The imaging lumen 32 can be positioned such that the central longitudinal axis X of the catheter shaft 12 is located within the imaging lumen 32, with the majority of the cross-sectional area of ​​the imaging lumen 32 being positioned on the opposite side of the plane Y that is parallel to and passes through the central longitudinal axis X.

[0064] Figure 2D Shown along Figure 2DFIG. 2 is an alternative cross-sectional view of a proximal portion of the catheter shaft 12 taken along the line 2-2. The proximal region of the catheter shaft 12 can have a circular cross-section with an outer diameter D1 of, for example, about 0.059 inches. In some cases, the outer diameter D1 can be about 0.06 inches or less, about 0.055 inches or less, or about 0.052 inches or less. In some cases, the outer diameter D1 can be about 0.059 inches, about 0.055 inches, about 0.052 inches, or about 0.050 inches. The outer diameter D1 can be sized such that the catheter shaft 12 of the catheter 10 can be positioned within a 6F guide catheter having an inner lumen diameter of about 0.070 inches, a 7F guide catheter having an inner lumen diameter of about 0.078 inches, or an 8F guide catheter having an inner lumen diameter of about 0.088 inches, along with an exchange device such as the outer diameter of about 0.026 inches. TM The outer diameter D1 can be sized such that the catheter shaft 12 of the catheter 10 can be positioned within a 6F guide catheter having an inner lumen diameter of about 0.070 inches, a 7F guide catheter having an inner lumen diameter of about 0.078 inches, or an 8F guide catheter having an inner lumen diameter of about 0.088 inches, along with an exchange device such as the outer diameter of about 0.026 inches.

[0065] The diameter D2 of the guidewire lumen 24 can be about 0.017 inches to accommodate a 0.014 inch guidewire. The first inflation lumen 26a and the second inflation lumen 26b can each have a diameter D3 of about 0.0115 inches or less or about 0.0105 inches or less. The imaging lumen 32 can be sized to accommodate an IVUS device such as the OptiCross® imaging catheter or its IVUS imaging core sold by Boston Scientific Corporation. The imaging lumen 32 can have a diameter D4 of about 0.015 inches or less, about 0.014 inches or less, or about 0.013 inches or less. TM The elongated shaft 202 of the imaging device 200 is shown positioned within the imaging lumen 32. For example, in some cases, the outer diameter of the IVUS imaging device can be about 0.025 inches or less. As shown, the imaging lumen 32 can have a circular cross-section with a radius of about 0.0125 inches (a diameter of about 0.025 inches) with an outer diameter D1 of about 0.059 inches. The catheter shaft 12 can include additional lumens such as the aspiration lumen 38 that extends parallel to and is spaced apart from the imaging lumen 32. In some embodiments, the aspiration lumen 38 can have a circular cross-section. In embodiments where the outer diameter D1 is about 0.059 inches, the aspiration lumen 38 can have a radius of about 0.01125 inches (a diameter of about 0.0225 inches). The lumens can be sized such that the thickness T of the catheter wall is at least 0.003 inches at all locations of the catheter shaft 12. In other cases, for example, the lumens can be sized such that the thickness T of the catheter wall is at least 0.002 inches, at least 0.0024 inches, at least 0.0026 inches, or at least 0.0028 inches at all locations of the catheter shaft 12. Figure 2D

[0066] As shown, the imaging lumen 32 can have a circular cross-section with a radius of about 0.0125 inches (a diameter of about 0.025 inches) with an outer diameter D1 of about 0.059 inches. The catheter shaft 12 can include additional lumens such as the aspiration lumen 38 that extends parallel to and is spaced apart from the imaging lumen 32. In some embodiments, the aspiration lumen 38 can have a circular cross-section. In embodiments where the outer diameter D1 is about 0.059 inches, the aspiration lumen 38 can have a radius of about 0.01125 inches (a diameter of about 0.0225 inches). The lumens can be sized such that the thickness T of the catheter wall is at least 0.003 inches at all locations of the catheter shaft 12. In other cases, for example, the lumens can be sized such that the thickness T of the catheter wall is at least 0.002 inches, at least 0.0024 inches, at least 0.0026 inches, or at least 0.0028 inches at all locations of the catheter shaft 12.

[0066] As shown, the imaging lumen 32 can have a circular cross-section with a radius of about 0.0125 inches (a diameter of about 0.025 inches) with an outer diameter D1 of about 0.059 inches. The catheter shaft 12 can include additional lumens such as the aspiration lumen 38 that extends parallel to and is spaced apart from the imaging lumen 32. In some embodiments, the aspiration lumen 38 can have a circular cross-section. In embodiments where the outer diameter D1 is about 0.059 inches, the aspiration lumen 38 can have a radius of about 0.01125 inches (a diameter of about 0.0225 inches). The lumens can be sized such that the thickness T of the catheter wall is at least 0.003 inches at all locations of the catheter shaft 12. In other cases, for example, the lumens can be sized such that the thickness T of the catheter wall is at least 0.002 inches, at least 0.0024 inches, at least 0.0026 inches, or at least 0.0028 inches at all locations of the catheter shaft 12. Figure 3As shown, the cross-sectional area of ​​the guidewire lumen 24 can be greater than the cross-sectional area of ​​each of the first inflation lumen 26 and the second inflation lumen 26, and the cross-sectional area of ​​the imaging lumen 32 can be greater than the cross-sectional area of ​​the guidewire lumen 24. The cross-sectional area of ​​the aspiration lumen 38 can be greater than or less than the cross-sectional area of ​​the guidewire lumen 24 and / or the imaging lumen 32. However, other configurations are also contemplated.

[0067] like Figure 1 As shown, the catheter shaft 12 can be configured such that each of the guidewire lumen 24 and the first and second inflation lumens 26a, 26b are positioned entirely on one side of a plane Y that is parallel to and passes through the central longitudinal axis X of the catheter shaft 12. The imaging lumen 32 and the aspiration lumen 38 can be positioned such that plane Y passes through each of the imaging lumen 32 and the aspiration lumen 38, with a majority of the cross-sectional area of ​​the imaging lumen 32 and a majority of the cross-sectional area of ​​the aspiration lumen 38 being positioned on opposite sides of the plane Y that is parallel to and passes through the central longitudinal axis X.

[0068] Steering Figure 2D , which is along Figures 2A-2D 3-3 , the catheter shaft 12 or a portion thereof may be an extruded shaft having a plurality of lumens formed therein. For example, the distal portion of the catheter shaft 12 may include a guidewire lumen 24, an inflation lumen 26 (which is shown as a bifurcated lumen including a first inflation lumen 26a and a second inflation lumen 26b, the second inflation lumen 26b extending parallel to and spaced apart from the first inflation lumen 26a), and one or more, or a plurality of, auxiliary lumens extending therethrough. For example, the distal portion of the catheter shaft 12 may include an imaging lumen 32 configured to accommodate an intravascular ultrasound (IVUS) imaging device and / or a suction lumen (see FIG. Figure 4 ). The elongated shaft 202 of the imaging device 200 is shown positioned within the imaging cavity 32.

[0069] The cross-sectional shape of the catheter shaft 12 in the distal portion of the catheter shaft 12 can be different from the cross-sectional shape of the catheter shaft 12 in the proximal portion of the catheter shaft 12. For example, as described above with respect to Figure 1 As shown, the proximal portion of the catheter shaft 12 can have a circular cross-sectional shape, while the distal portion of the catheter shaft 12 can have a non-circular cross-sectional shape, such as a generally rectangular cross-sectional shape.

[0070] The location and arrangement of the lumens in the proximal portion of the catheter shaft 12 can be different than the location and arrangement of the lumens in the distal portion of the catheter shaft 12. For example, in the distal portion of the catheter shaft 12, the first inflation lumen 26a and the second inflation lumen 26b can be positioned on opposite sides of the imaging lumen 32 and the guidewire lumen 24, with the imaging lumen 32 and the guidewire lumen 24 positioned between the first inflation lumen 26a and the second inflation lumen 26b. The imaging lumen 32, the guidewire lumen 24, and the first inflation lumen 26a and the second inflation lumen 26b can be positioned (e.g., aligned) such that a plane Y extending parallel to the central longitudinal axis X of the catheter shaft and passing therethrough passes through each of the imaging lumen 32, the guidewire lumen 24, and the first inflation lumen 26a and the second inflation lumen 26b. In some cases, the plane Y can pass through or near the center of each of the imaging lumen 32 and the guidewire lumen 24.

[0071] For example, the overall width W (measured parallel to the plane Y) of the distal portion of the catheter shaft 12 can be about 0.07 inches or less, about 0.068 inches or less, 0.066 inches or less, or 0.065 inches or less. For example, the overall height H (measured perpendicular to the width W) of the distal portion of the catheter shaft 12 can be about 0.035 inches or less, about 0.033 inches or less, or about 0.032 inches or less.

[0072] The diameter D2 of the guidewire lumen 24 can be about 0.017 inches to accommodate a 0.014 inch guidewire. The diameter D4 of the imaging lumen 32 can be about 0.026 inches to accommodate an IVUS imaging catheter. The width D5 of each of the first inflation lumen 26a and the second inflation lumen 26b can be about 0.0037 inches. The lumens can be sized such that the thickness T of the catheter wall is at least 0.003 inches at all locations of the catheter shaft 12. In other cases, for example, the lumens can be sized such that the thickness T of the catheter wall is at least 0.002 inches, at least 0.0024 inches, at least 0.0026 inches, or at least 0.0028 inches at all locations of the catheter shaft 12.

[0073] The extruded proximal portion of the catheter shaft 12 can be joined to the extruded distal portion of the catheter shaft 12 such that the lumens of the proximal portion of the catheter shaft 12 are in communication with the corresponding lumens of the distal portion of the catheter shaft 12. In other words, the lumens described above can be continuous through the proximal and distal portions of the catheter shaft 12, while the cross-sectional shape of the proximal portion of the catheter shaft 12 can be different than the cross-sectional shape of the distal portion of the catheter shaft 12.

[0074] Turning to Figure 4 which is along Figure 5FIG. 4 is a cross-sectional view of a distal region of the catheter shaft 12 taken along the line 4-4, including the expandable balloon 20 of the catheter shaft 12. In some cases, the first inflatable balloon member 20a and the second inflatable balloon member 20b of the expandable balloon 20 can be formed as a single or unitary portion of the catheter shaft 12. However, in other cases, the first inflatable balloon member 20a and the second inflatable balloon member 20b of the expandable balloon 20 can be formed separately and subsequently secured to the catheter shaft 12. As shown, the first inflation lumen 26a can open to the interior of the first inflatable balloon member 20a, and the second inflation lumen 26b can open to the interior of the second inflatable balloon member 20b. Figure 5

[0075] The overall width Wl of the expandable balloon 20 (including the first inflatable balloon member 20a and the second inflatable balloon member 20b) can be about 0.142 inches when inflated. In some cases, for example, the overall width Wl can be about 0.14 inches or greater, about 0.16 inches or greater, about 0.18 inches or greater, about 0.20 inches or greater, about 0.14 inches, about 0.16 inches, about 0.18 inches, about 0.20 inches, within a range of about 0.14 inches to about 0.20 inches, or within a range of about 0.16 inches to about 0.22 inches. For example, the overall height Hl of the expandable balloon 20 (measured perpendicular to the width Wl) (e.g., the height of either of the first and / or second inflatable balloon members 20a, 20b) can be about 0.023 inches when inflated. Thus, the width of the inflatable balloon 20 when inflated can be greater than the height of the inflatable balloon 20. For example, the expandable balloon 20 can have a width-to-height ratio of about 2: 1 or greater, 3: 1 or greater, 4: 1 or greater, 5: 1 or greater, or 6: 1 or greater when inflated.

[0076] The distal region of the elongate shaft 12 can also include a first lateral opening 50 that opens to the exterior of the catheter shaft 12 between the first inflatable balloon member 26a and the second inflatable balloon member 26b. In some cases, the distal region of the elongate shaft 12 can also include a second lateral opening 52 (also seen in FIG. 3) that opens to the exterior of the catheter shaft 12 between the first inflatable balloon member 26a and the second inflatable balloon member 26b. Figure 5 ​), which opens to the exterior of the catheter shaft 12 between the first inflatable balloon member 26a and the second inflatable balloon member 26b. Each of the first lateral opening 50 and the second lateral opening 52 can be in communication with the guidewire lumen 24. The first lateral opening 50 and the second lateral opening 52 can each extend through the sidewall of the catheter shaft 12. For example, the first lateral opening 50 can extend through the sidewall of the catheter shaft 12 on a first side of the catheter shaft 12 exposed between the first inflatable balloon member 26a and the second inflatable balloon member 26b, and the second lateral opening 52 can extend through the sidewall of the catheter shaft 12 on an opposite second side of the catheter shaft 12 exposed between the first inflatable balloon member 26a and the second inflatable balloon member 26b.

[0077] During a recanalization procedure, each of the first lateral opening 50 and the second lateral opening 52 can be configured to allow a re-entry device or penetrating member to be advanced therethrough to penetrate through the tissue layers of the vessel wall from the subintimal space into the true lumen of the vessel. For example, a distal portion of a re-entry device or penetrating member that can be advanced through the guidewire lumen 24 can be passed laterally out of the catheter shaft 12 through the first lateral opening 50 or the second lateral opening 52 to penetrate through the tissue layers of the vessel.

[0078] like Figures 6-10 As shown, in some cases, the first lateral opening 50 can be located in the distal region of the catheter shaft 12 and between the proximal and distal ends of the expandable balloon 20, for example, at a position between the proximal and distal ends of the first and second inflatable balloon members 20a, 20b. Alternatively, the second lateral opening 52 can be located in the distal region of the catheter shaft 12 between the proximal and distal ends of the expandable balloon 20, for example, at a position between the proximal and distal ends of the first and second inflatable balloon members 20a, 20b. In other cases, the first lateral opening 50 and / or the second lateral opening 52 can be located at other positions in the distal region of the catheter shaft 12, such as proximal to the proximal end of the expandable balloon 20 or distal to the distal end of the expandable balloon 20. The first lateral opening 50 and the second lateral opening 52 can be longitudinally offset (i.e., axially spaced) from each other along the catheter shaft 12. For example, the first lateral opening 50 can be located proximal to the second lateral opening 52. The catheter shaft 12 can also include a radiopaque marker 51 located proximate to the first lateral opening 50 to provide an indication of the location of the first lateral opening 50 under fluoroscopy. Additionally, the catheter shaft 12 can include a radiopaque marker 53 located proximate to the second lateral opening 52 to provide an indication of the location of the second lateral opening 52 under fluoroscopy.

[0079] Figure 6The guide wire 100 is also shown positioned within the guide wire lumen 24 of the catheter shaft 12, and an IVUS imaging device 200 (e.g., an IVUS imaging catheter or core) includes an ultrasound transducer 210 at its distal end positioned within the imaging lumen 32 of the catheter shaft 12. The IVUS imaging device 200 can be longitudinally movable within the imaging lumen 32 such that, during a medical procedure, the imaging device 200 can be advanced distally relative to the catheter shaft 12 and withdrawn proximally relative to the catheter shaft 12 to position the ultrasound transducer 210 at a desired location within the imaging lumen 32. In other cases, the IVUS imaging device 200 can be fixedly immovable longitudinally within the imaging lumen 32. In some embodiments, the ultrasound transducer 210 can be positioned or positionable distal of the first lateral opening 50, distal of the second lateral opening 52, and / or distal of the expandable balloon 20 such that the imaging device can provide ultrasound images of the true lumen of the vessel from which the re-entry device originates the trajectory of the catheter shaft 12.

[0080] In some cases, it can not be necessary, difficult, or possible to pass a medical device through an occlusion, such as a chronic total occlusion (CTO) in the lumen of a blood vessel to achieve revascularization of the blood vessel. In such cases, the catheter 10 can be used to achieve revascularization of the blood vessel through a subintimal approach. As will be further described herein, the catheter 10 can be configured to facilitate re-entry into the true lumen of the blood vessel distal of an occlusion (e.g., a chronic total occlusion) from a subintimal space formed in the wall of the blood vessel that bypasses the occlusion. For example, a distal portion of the catheter shaft 12 (including the expandable balloon 20) can be advanced into a subintimal space created in the wall of the blood vessel, such as by dissecting tissue layers of the wall of the blood vessel. Once positioned in the subintimal space, the first inflatable balloon member 20a and the second inflatable balloon member 20b of the expandable balloon 20 can be inflated between the intimal layer and the adventitial layer of the wall of the blood vessel to an expanded / inflated configuration. When the first balloon member 20a and the second balloon member 20b are inflated to the expanded / inflated configuration, the first balloon member 20a and the second balloon member 20b extend laterally from the catheter shaft 12 within the subintimal space formed in the wall of the blood vessel to automatically orient the first lateral opening 50 or the second lateral opening 52 radially inward toward the true lumen of the blood vessel. A re-entry device (e.g., a re-entry guide wire or other penetrating member) can be advanced through the guide wire lumen 24 and out through the first lateral opening 50 or the second lateral opening 52 (facing either of the true lumens) to penetrate from the subintimal location through the intimal layer into the true lumen.

[0081] Turning to Figure 7, illustrates aspects of an exemplary method for recanalizing an occluded blood vessel 80 using a catheter 10. The blood vessel 80 typically has three tissue layers, an innermost or intimal layer (i.e., the intima) 82, a middle or medial layer (i.e., the tunica media) 84, and an outermost or adventitial layer (i.e., the adventitia) 86, wherein the medial layer 84 is positioned between the intimal layer 82 and the adventitial layer 86. The intimal layer 82 is a layer of endothelial cells lining the lumen 88 of the blood vessel 90, and a subendothelial layer composed primarily of loose connective tissue. The medial layer 84 is a muscle layer formed primarily of circumferentially arranged smooth muscle cells. The adventitial layer 86, which forms the outer layer of the blood vessel wall 80, is formed primarily of loose connective tissue composed primarily of fibroblasts and associated collagen fibers.

[0082] like Figure 7 As shown, the guidewire 100 can first be advanced through the lumen 88 of the blood vessel 80 to a position proximal to the occlusion 90 that blocks the lumen 88. The guidewire 100 can then be advanced to penetrate outward through the intimal layer 82 into the wall of the blood vessel 801 at a position proximal to the proximal end of the occlusion 90. With the tip of the guidewire 100 positioned between the intimal layer 82 and the adventitial layer 86, the guidewire 100 can be further advanced distally in a subintimal manner to create a subintimal space between the intimal layer 82 and the adventitial layer 86. Figure 8 As shown, the guidewire 100 can be advanced in a subintimal manner until the distal tip of the guidewire 100 is located distal to the distal end of the occlusion 90 in the created subintimal space, such as by peeling away the tissue layers of the wall of the blood vessel 80. In some cases, another catheter device can be used first to exit the lumen 88 proximal to the occlusion 90 and form the subintimal space. In such cases, the guidewire 100 can then be advanced through the catheter into the subintimal space, and the catheter can be withdrawn, leaving the guidewire 100 positioned in the subintimal space, as shown. Figure 10 shown.

[0083] The recanalization catheter 10 can then be advanced distally over the guidewire 100 from the true lumen 88 proximal to the occlusion 90 into the subintimal space between the intimal layer 82 and the adventitial layer 86 to a position in the subintimal space in which the distal portion of the catheter 10, including the expandable balloon 20, is distal to the distal end of the occlusion 90, as shown. Figure 10 The recanalization catheter 10 can be advanced through the subintimal space in a delivery configuration, such as with the expandable balloon 20 in a deflated and collapsed configuration.

[0084] The IVUS imaging device 200 can be advanced through the imaging lumen 32, or otherwise positioned within the imaging lumen 32, to position the imaging transducer 210 distal of the occlusion 90 to obtain ultrasound images of the true lumen 88 and confirm that the recanalization catheter 10 has been sufficiently advanced beyond the occlusion 90 for successful recanalization of the true lumen 88 with a recanalization device advanced from the recanalization catheter 10. The ultrasound transducer 210 can be positioned distal of the first lateral opening 50, the second lateral opening 52, and / or distal of the expandable balloon 20 so that the imaging device can provide ultrasound images of the trajectory of the recanalization device from the catheter shaft 12. In some cases, the imaging device 200 can be advanced into the subintimal space with the catheter 10. In other cases, the imaging device 200 can be advanced through the imaging lumen 32 after the recanalization catheter 10 is advanced into the subintimal space.

[0085] Additionally, once positioned in the subintimal space, the first and second inflatable balloon members 20a, 20b of the expandable balloon 20 can be inflated to an expanded / inflated configuration between the intimal and adventitial layers of the vessel wall, as shown in FIG. 6. The first and second balloon members 20a, 20b can be inflated prior to or after confirmation of the desired placement of the recanalization catheter 10 distal of the occlusion 90 using the imaging device 200. When the first and second balloon members 20a, 20b are inflated to the expanded / inflated configuration, the first and second balloon members 20a, 20b extend laterally from the catheter shaft 12 within the subintimal space formed in the vessel wall to automatically orient the first lateral opening 50 or the second lateral opening 52 radially inward toward the true lumen 88 of the vessel 80. As shown in FIG. 6, the expansion / inflation of the inflatable balloon members 20a, 20b can rotationally orient the catheter shaft 12 in one of two possible orientations, with the first lateral opening 50 facing the true lumen 88 of the vessel 80, or with the second lateral opening 52 facing the true lumen 88 of the vessel 80. Figure 9 Figure 10 As shown in FIG. 6, the expansion / inflation of the inflatable balloon members 20a, 20b can rotationally orient the catheter shaft 12 in one of two possible orientations, with the first lateral opening 50 facing the true lumen 88 of the vessel 80, or with the second lateral opening 52 facing the true lumen 88 of the vessel 80.

[0086] If desired, blood within the subintimal space can be aspirated through the imaging lumen (or through the separate aspiration lumen 38, if provided) external to the IVUS imaging device 200 to reduce the pressure in the subintimal space and / or pull the intimal layer 86 against the catheter shaft 12. Aspiration of blood from the subintimal space can also prevent collapse of the true lumen 88 distal of the occlusion 90.

[0087] The guidewire 100 can be withdrawn from the guidewire lumen 24, and the elongate recanalization device or penetrating member 120 can then be advanced through the guidewire lumen 24 of the catheter 10 and out of the first lateral opening 50 (if the first lateral opening 50 is facing the true lumen 88) to penetrate through the intimal layer 82 into the true lumen 88 distal of the occlusion 90, as shown in FIG. 7.​Figure 8 It should be noted that if the expandable balloon 20 is inflated such that the catheter shaft 12 is oriented with the second lateral opening 52 facing the true lumen 88, an elongate re-entry device or penetrating member 120 can be advanced through the guide wire lumen 24 of the catheter 10 and out of the second lateral opening 52 to penetrate through the intimal layer 82 into the true lumen 88 distal of the occlusion 90. In some embodiments, the re-entry device or penetrating member 120 can be a guide wire 100, or another guide wire introduced through the guide wire lumen 24 of the catheter shaft 12. In some cases, the re-entry device can have a pre-formed curved distal end portion, where the distal end portion is curved at an oblique angle to the proximal portion of the re-entry device. The curved distal end portion can facilitate exiting the first lateral opening 50 or the second lateral opening 52 when the distal tip of the re-entry device or penetrating member 120 encounters the lateral opening. In other cases, the re-entry catheter 10 can include a deflection mechanism to deflect the re-entry device or penetrating member 120 outward through the first lateral opening 50 or the second lateral opening 52. In some cases, the re-entry device or penetrating member 120 can include a reduced diameter penetrating tip 125 (as shown), to facilitate penetrating through the intimal layer 82. In other embodiments, the re-entry device or penetrating member 120 can be an elongate member, such as a needle tube or stylet, having a sharp distal tip configured to pierce through the intimal layer 82 into the lumen 88 distal of the occlusion 90. Figure 11 It should be noted that if the expandable balloon 20 is inflated such that the catheter shaft 12 is oriented with the second lateral opening 52 facing the true lumen 88, an elongate re-entry device or penetrating member 120 can be advanced through the guide wire lumen 24 of the catheter 10 and out of the second lateral opening 52 to penetrate through the intimal layer 82 into the true lumen 88 distal of the occlusion 90. In some embodiments, the re-entry device or penetrating member 120 can be a guide wire 100, or another guide wire introduced through the guide wire lumen 24 of the catheter shaft 12. In some cases, the re-entry device can have a pre-formed curved distal end portion, where the distal end portion is curved at an oblique angle to the proximal portion of the re-entry device. The curved distal end portion can facilitate exiting the first lateral opening 50 or the second lateral opening 52 when the distal tip of the re-entry device or penetrating member 120 encounters the lateral opening. In other cases, the re-entry catheter 10 can include a deflection mechanism to deflect the re-entry device or penetrating member 120 outward through the first lateral opening 50 or the second lateral opening 52. In some cases, the re-entry device or penetrating member 120 can include a reduced diameter penetrating tip 125 (as shown), to facilitate penetrating through the intimal layer 82. In other embodiments, the re-entry device or penetrating member 120 can be an elongate member, such as a needle tube or stylet, having a sharp distal tip configured to pierce through the intimal layer 82 into the lumen 88 distal of the occlusion 90.

[0088] In some cases, the trajectory of the re-entry device or penetrating member 120 from the catheter shaft 12 can be confirmed using fluoroscopy to ensure that the re-entry or penetrating member 120 is being advanced toward the true lumen 88, and not radially outward through the adventitial layer 86. Additionally or alternatively, an ultrasound image of the true lumen 88 can be obtained using the IVUS imaging device 200, and the trajectory of the re-entry device or penetrating member 120 can be confirmed to ensure that the re-entry device or penetrating member 120 is being advanced toward the true lumen 88. Because the imaging lumen 32 is laterally disposed alongside the guide wire lumen 24, such that the IVUS imaging device 200 is laterally positioned in the vicinity of the re-entry or penetrating member 120, the presence of the re-entry device or penetrating member 120 does not obstruct or interfere with the imaging capabilities of the IVUS transducer 120, such that the IVUS transducer 210 is able to acquire clear images toward the true lumen 88 through an angle of about 90 to about 150 degrees.

[0089] In cases where the re-entry device or penetrating member 120 is a guide wire, the catheter 10 can be withdrawn, leaving the guide wire routed around the occlusion 90 via the subintimal path. In cases where the re-entry device or penetrating member 120 is a separate elongate member, such as a needle tube or stylet, the re-entry device or penetrating member 120 can be withdrawn and replaced with a guide wire. The catheter 10 and / or the penetrating member 120 can be withdrawn, leaving the guide wire routed around the occlusion 90 via the subintimal path.

[0090] In some cases, a capture balloon catheter can be used to maintain the position of the re-entry device / penetration member 120 (or a subsequently placed guidewire) around the occlusion 90 through the subintimal path while the recanalization catheter 10 is withdrawn. For example, the recanalization catheter 10 can be advanced through a guide catheter, such as a 6F, 7F, or 8F guide catheter, to reach the subintimal space alongside the occlusion 90, as shown in FIG. 6. Prior to withdrawing the recanalization catheter 10 from the blood vessel after successful re-entry into the true lumen distal to the occlusion 90, the capture balloon catheter can be advanced through the guide catheter outside of the recanalization catheter 10, and the capture balloon of the capture balloon catheter can then be inflated inside the guide catheter distal to the recanalization catheter 10 to secure the re-entry device / penetration member 120 or other guidewire against the inner wall of the guide catheter. With the re-entry device / penetration member 120 or other guidewire securely fixed to the inner wall of the guide catheter to prevent longitudinal movement thereof, the recanalization catheter 10 can be withdrawn from the guide catheter and the blood vessel 80. Once the recanalization catheter 10 is withdrawn, the capture balloon of the capture balloon catheter can be deflated, leaving the re-entry device / penetration member 120 or other guidewire in place. Figure 12

[0091] Once a path has been created across the occlusion 90 (e.g., via a subintimal track around the occlusion 90), one or more additional medical devices can be advanced over the re-entry device / penetration member 120 or other guidewire through the blood vessel 80 to enlarge the path and / or to pass distal to the occlusion 90 to perform further medical procedures.

[0092] Figure 12 is a plan view of an exemplary catheter 110 for vascular recanalization. The catheter 110 can include an elongated catheter shaft 112 extending distally from a hub assembly 114 to a distal tip 122 of the catheter shaft 112. As shown in the cross-sectional view of Figure 12 The catheter shaft 112 can include a guidewire lumen 24 and an imaging lumen 32 extending therethrough, as shown in the cross-sectional view of FIG. 5. A distal end region of the catheter shaft 112 can include a lateral opening 150 in communication with the guidewire lumen 24. In some cases, the guidewire lumen 24 can extend from the proximal guidewire port 130 to the distal tip 122 of the catheter shaft 12, or the guidewire lumen 24 can terminate at the lateral opening 150. The imaging lumen 32 can extend distally from the proximal port 36 through the catheter shaft 12 beyond the lateral opening 150. In some cases, the imaging lumen 32 can extend to the distal tip 122, or the imaging lumen 32 can terminate proximal to the distal tip 122.

[0093] As shown in FIG. 6, the catheter 110 can be used to re-enter the true lumen distal to the occlusion 90. The catheter 110 can be advanced through the guide catheter 20 until the distal tip 122 of the catheter shaft 112 is positioned distal to the occlusion 90. The catheter 110 can be rotated to align the lateral opening 150 with the re-entry device / penetration member 120 or other guidewire. The catheter 110 can be advanced over the re-entry device / penetration member 120 or other guidewire until the lateral opening 150 is aligned with the re-entry device / penetration member 120 or other guidewire. The capture balloon of the capture balloon catheter can then be inflated to secure the re-entry device / penetration member 120 or other guidewire against the inner wall of the guide catheter 20. The recanalization catheter 10 can then be withdrawn from the guide catheter 20 and the blood vessel 80. Once the recanalization catheter 10 is withdrawn, the capture balloon of the capture balloon catheter can be deflated, leaving the re-entry device / penetration member 120 or other guidewire in place. Figure 12 ​As shown, the catheter shaft 112 can have a circular cross-section with an outer diameter D1 of approximately 0.059 inches. In some cases, for example, the outer diameter D1 can be approximately 0.06 inches or less, approximately 0.055 inches or less, or approximately 0.052 inches or less. In some cases, for example, the outer diameter D1 can be approximately 0.059 inches, approximately 0.055 inches, approximately 0.052 inches, or approximately 0.050 inches. The outer diameter D1 can be sized so that the catheter shaft 112 of the catheter 110 can be attached to a capture balloon catheter such as the Trapper® sold by Boston Scientific Corporation. TM An exchange device, for example having an outer diameter of approximately 0.026 inches, is positioned together in a 6F guide catheter having an inner lumen diameter of approximately 0.07 inches (such as in the range of approximately 0.070 inches to approximately 0.072 inches), in a 7F guide catheter having an inner lumen diameter of approximately 0.08 inches (such as in the range of approximately 0.078 inches to approximately 0.082 inches), or in an 8F guide catheter having an inner lumen diameter of approximately 0.09 inches (such as in the range of approximately 0.088 inches to approximately 0.091 inches).

[0094] The diameter D2 of the guidewire lumen 24 may be approximately 0.017 inches to accommodate a 0.014 inch guidewire. The imaging lumen 32 may be sized to accommodate an IVUS device, such as the OptiCross® sold by Boston Scientific Corporation. TM The imaging catheter or its IVUS imaging core can also provide a space for fluid aspiration therethrough together with the IVUS imaging device. For example, in some cases, the outer diameter of the IVUS imaging device can be about 0.025 inches or less.

[0095] like Figure 12As shown, where the outer diameter D1 is approximately 0.059 inches, the imaging cavity 32 can have a non-circular cross-section (which is shown as an elliptical cross-section) with a minor radius R1 of approximately 0.0165 inches and a major radius R2 of approximately 0.0212 inches, thereby providing the imaging cavity 32 with a distance across its minor axis of approximately 0.0330 inches, a distance across its major axis of approximately 0.0424 inches, an area of ​​approximately 0.00110 square inches, and a circumference of approximately 0.1189 inches. In other cases, such as when the outer diameter D1 is approximately 0.052 inches, the imaging lumen 32 can have an elliptical cross-section with a minor radius R1 of approximately 0.0130 inches and a major radius R2 of approximately 0.0175 inches, thereby providing the imaging lumen 32 with a distance across its minor axis of approximately 0.026 inches, a distance across its major axis of approximately 0.035 inches, an area of ​​approximately 0.0007147 square inches, and a circumference of approximately 0.09634 inches. The lumen can be sized such that the thickness T of the catheter wall is at least 0.003 inches at all locations on the catheter shaft 12. In other cases, for example, the lumen can be sized such that the thickness T of the catheter wall is at least 0.002 inches, at least 0.0024 inches, at least 0.0026 inches, or at least 0.0028 inches at all locations on the catheter shaft 112.

[0096] like Figure 12 As shown, the cross-sectional area of ​​the imaging lumen 32 may be greater than the cross-sectional area of ​​the guidewire lumen 24. However, other configurations are also contemplated.

[0097] like ​ As shown, the catheter shaft 112 can be configured such that the guidewire lumen 24 is positioned entirely on one side of a plane Y that is parallel to and passes through a central longitudinal axis X of the catheter shaft 112. The imaging lumen 32 can be positioned such that the central longitudinal axis X of the catheter shaft 112 is located within the imaging lumen 32, with the majority of the cross-sectional area of ​​the imaging lumen 32 being positioned on an opposite side of the plane Y that is parallel to and passes through the central longitudinal axis X.

[0098] In addition, if ​ As shown, catheter shaft 112 can be configured such that plane Z, which extends parallel to and passes through central longitudinal axis X, passes through the center of each of guidewire lumen 24 and imaging lumen 32. In some cases, plane Z can be perpendicular to plane Y.

[0099] The catheter shaft 112 can include a reinforcing structure 162, such as a braid or coil, to facilitate torque transmission of the catheter shaft such that the side opening can be rotationally oriented toward the true lumen of the vessel located distal to the occlusion. For example, the catheter shaft 112 can include an extruded tubular member 160 defining the guidewire lumen 24 and the imaging lumen 32. A reinforcing structure 162, such as a braid or coil, can be disposed around (i.e., surrounding) the extruded tubular member 160, and an outer layer 164 can surround the reinforcing structure 162. Thus, the catheter 110 can not include a balloon for rotational orientation.

[0100] The catheter 110 can be advanced into the subintimal space in a manner similar to that described above with respect to the catheter 10. The imaging lumen 32 is configured to receive an IVUS imaging device therein, as discussed above. The IVUS imaging device is configured to provide ultrasound images of the vessel to confirm the rotational orientation of the side opening 150 in the subintimal space and / or the trajectory of the re-entry device from the side opening 150 toward the true lumen. For example, once the orientation of the side opening 150 is confirmed with the IVUS imaging device, the re-entry device can be advanced through the guidewire lumen 24 and out of the side opening 150 to re-enter the true lumen located distal to the occlusion.

[0101] Those skilled in the art will realize that various aspects of the present application can be realized in various forms. Therefore, the embodiments described and envisaged herein are to be considered in all respects as illustrative and not restrictive.

Claims

1. A recanalization catheter to facilitate recanalization of a lumen of a blood vessel having an occlusion therein from a subintimal space in a wall of the blood vessel, the recanalization catheter comprising: a catheter shaft extending distally from a hub, the catheter shaft defining a guidewire lumen extending therethrough; a first inflatable balloon member and a second inflatable balloon member disposed on a distal end region of the catheter shaft, the catheter shaft including an inflation lumen in fluid communication with the first and second inflatable balloon members; a lateral opening in communication with the guidewire lumen, wherein the lateral opening opens to an exterior of the catheter shaft between the first and second inflatable balloon members on a first side of the catheter shaft; and an imaging lumen extending through the catheter shaft, the imaging lumen configured to receive an IVUS imaging device therein.

2. The recanalization catheter of claim 1, wherein the inflation lumen includes a first inflation lumen in fluid communication with the first inflatable balloon member, and a second inflation lumen in fluid communication with the second inflatable balloon member.

3. The recanalization catheter of claim 2, wherein in a proximal portion of the catheter shaft, a central longitudinal axis of the catheter shaft passes through the imaging lumen, and all of each of the first inflation lumen, the second inflation lumen, and the guidewire lumen are positioned on a first side of a first imaginary plane, the first imaginary plane extending parallel to and passing through the central longitudinal axis.

4. The recanalization catheter of claim 3, wherein in a distal portion of the catheter shaft, the imaging lumen and the guidewire lumen are positioned between the first and second inflation lumens, such that a second imaginary plane passes through each of the first inflation lumen, the second inflation lumen, the imaging lumen, and the guidewire lumen, the second imaginary plane extending parallel to and passing through the central longitudinal axis.

5. The recanalization catheter of any of the preceding claims, wherein a proximal portion of the catheter shaft has a circular cross-sectional shape, and a distal portion of the catheter shaft has a generally rectangular cross-sectional shape.

6. The recanalization catheter of any of the preceding claims, wherein the first and second inflatable balloon members are configured to be inflated laterally from opposite sides of the catheter shaft along a third imaginary plane, wherein the third imaginary plane passes through each of the imaging lumen and the guidewire lumen.

7. The recanalization catheter of any of the preceding claims, further comprising an IVUS imaging device positionable within the imaging lumen to position an IVUS transducer distally of the first lateral opening.

8. The recanalization catheter of any of claims 1-7, wherein an outer diameter of the catheter shaft is 0.059 inches or less, a diameter of the guidewire lumen is about 0.017 inches, and a minimum distance across the imaging lumen by a central axis of the imaging lumen is 0.033 inches or greater. ​ 9. The recanalization catheter of any of claims 1-7, wherein the catheter shaft has an outer diameter of 0.052 inches or less, the guidewire lumen has a diameter of about 0.017 inches, and a minimum distance across the imaging lumen through a central axis of the imaging lumen is 0.026 inches or greater.

10. The recanalization catheter of claim 8 or 9, wherein the catheter shaft has a wall thickness of at least 0.003 inches at all locations along the catheter shaft.

11. A recanalization catheter to facilitate re-entry into a lumen of a blood vessel having an occlusion therein from a subintimal space in a wall of the blood vessel, the recanalization catheter comprising: a catheter shaft extending distally from a hub; an expandable balloon disposed on a distal end region of the catheter shaft; wherein the catheter shaft is an extruded tubular member defining: a guidewire lumen extending therethrough; an inflation lumen in fluid communication with an interior of the expandable balloon; and an imaging lumen extending through the catheter shaft, the imaging lumen configured to receive an IVUS imaging device therein.

12. The recanalization catheter of claim 11, further comprising an IVUS imaging device positionable within the imaging lumen such that an IVUS transducer of the IVUS imaging device is distal of the expandable balloon.

13. A recanalization catheter to facilitate re-entry into a lumen of a blood vessel having an occlusion therein from a subintimal space in a wall of the blood vessel, the recanalization catheter comprising: a catheter shaft extending distally from a hub; an expandable balloon disposed on a distal end region of the catheter shaft, the expandable balloon including a first inflatable balloon member on a first side of the catheter shaft and a second inflatable balloon member on a second side of the catheter shaft opposite the first side; wherein the catheter shaft includes an extruded proximal tubular member having a circular cross-sectional shape and an extruded distal tubular member having a generally rectangular cross-sectional shape, the catheter shaft defining: a guidewire lumen extending through the extruded proximal tubular member and the extruded distal tubular member; a first inflation lumen extending through the extruded proximal tubular member and the extruded distal tubular member, the first inflation lumen in fluid communication with an interior of the first inflatable balloon member; a second inflation lumen extending through the extruded proximal tubular member and the extruded distal tubular member, the second inflation lumen in fluid communication with an interior of the second inflatable balloon member; and an imaging lumen extending through the extruded proximal tubular member and the extruded distal tubular member, the imaging lumen configured to receive an IVUS imaging device therein.

14. The recanalization catheter of claim 13, further comprising a lateral opening in communication with the guidewire lumen, wherein the lateral opening opens to an exterior of the catheter shaft between the first inflatable balloon member and the second inflatable balloon member. ​ 15. The recanalization catheter of claim 14, further comprising an IVUS imaging device positionable within the imaging lumen such that an IVUS transducer of the IVUS imaging device is distal of the lateral opening, preferably distal of the expandable balloon.

Images