Subintima re-entry catheter with intravascular ultrasound function

Abstract

A recanalization catheter for facilitating re-entry into the lumen of a blood vessel from the subintima-space of the wall of a vessel having an internal occlusion. The recanalization catheter includes a catheter shaft extending distally from a hub. The catheter shaft defines a guidewire lumen extending through it. First and second inflatable balloon members are positioned in the distal end region of the catheter shaft. The catheter shaft includes an inflatable lumen that is in fluid communication with the first and second inflatable balloon members. A lateral opening communicating with the guidewire lumen opens to the outside of the catheter shaft between the first and second inflatable balloon members on the first side of the catheter shaft. The catheter shaft also includes an imaging lumen extending through the catheter shaft, configured to receive an IVUS imaging device therein.

Description

Technical Field

[0001] The present disclosure relates to devices and methods for the recanalization of occluded blood vessels. More specifically, the present disclosure relates to devices and methods for reentry from an extra-luminal or sub-intimal space of a blood vessel into the true lumen.

Background Art

[0002] A chronic total occlusion (CTO) is an occlusion of an arterial blood vessel that impedes blood flow through the vessel, and can occur in both coronary and peripheral arteries. In some cases, it may be difficult or impossible to pass a CTO using a medical device in the antegrade direction in order to recanalize the blood vessel. Therefore, techniques have been developed to form a sub-intimal pathway (i.e., a pathway between the intimal tissue layer and the adventitial tissue layer of the blood vessel) around the occlusion, and then re-enter the true lumen of the blood vessel distal to the occlusion in an attempt to recanalize the blood vessel. In some cases, it may be difficult to re-enter and / or recanalize from the sub-intimal space into the true lumen using only angiography. Therefore, there is a desire to provide alternative recanalization devices with integrated intravascular ultrasound (IVUS) to enable live imaging between sub-intimal advancement and re-entry, and / or related methods for recanalizing blood vessels in which a CTO is present.

Summary of the Invention

Means for Solving the Problems

[0003] The present disclosure relates to several alternative designs, materials and methods for manufacturing the structure and assembly of a medical device, and their use. Therefore, one exemplary embodiment is a recanalization catheter for facilitating reentry from the subintima-space of the wall of a vessel having an occlusion therein into the lumen of the vessel. The recanalization catheter includes a catheter shaft extending distally from a hub. The catheter shaft defines a guidewire lumen extending through it. First and second inflatable balloon members are positioned in the distal end region of the catheter shaft. The catheter shaft includes an inflatable lumen that is in fluid communication with the first and second inflatable balloon members. A lateral opening communicating with the guidewire lumen opens to the outside of the catheter shaft between the first and second inflatable balloon members on the first side of the catheter shaft. The catheter shaft also includes an imaging lumen extending through it, configured to receive an IVUS imaging device therein.

[0004] In addition to or as an alternative to any embodiment disclosed herein, the expansion lumen includes a first expansion lumen in fluid communication with a first inflatable balloon member and a second expansion lumen in fluid communication with a second inflatable balloon member.

[0005] In addition to or as an alternative to any embodiment disclosed herein, in the proximal portion of the catheter shaft, the central longitudinal axis of the catheter shaft passes through the imaging lumen, and the entirety of the first expansion lumen, the second expansion lumen, and the guidewire lumen are located on the first side of a first imaginary plane that extends parallel to and passes through the central longitudinal axis.

[0006] In addition to or as an alternative to any embodiment disclosed herein, in the distal portion of the catheter shaft, the imaging lumen and guidewire lumen are positioned between the first and second expansion lumen such that a second virtual plane extending parallel to and passing through the central longitudinal axis passes through the first expansion lumen, the second expansion lumen, the imaging lumen, and the guidewire lumen, respectively.

[0007] In addition to or as an alternative to any embodiment disclosed herein, the proximal portion of the catheter shaft may have a circular cross-sectional shape, and the distal portion of the catheter shaft may have a substantially rectangular cross-sectional shape.

[0008] In addition to or as an alternative to any embodiment disclosed herein, the first and second inflatable balloon members are configured to inflate laterally from both sides of the catheter shaft along a third virtual plane, the third virtual plane passing through the imaging lumen and the guidewire lumen, respectively.

[0009] In addition to or as an alternative to any embodiment disclosed herein, the re-canalization catheter further includes an IVUS imaging device that can be positioned in the imaging lumen to position an IVUS transducer distal to the first lateral opening.

[0010] In addition to or as an alternative to any embodiment disclosed herein, the outer diameter of the catheter shaft is 0.059 inches (0.150 cm) or less, the guidewire lumen has a diameter of approximately 0.017 inches (0.043 cm), and the minimum distance across the imaging lumen through the central axis of the imaging lumen is 0.033 inches (0.084 cm) or more.

[0011] In addition to or as an alternative to any embodiment disclosed herein, the outer diameter of the catheter shaft is 0.052 inches (0.132 cm) or less, the guidewire lumen has a diameter of approximately 0.017 inches (0.043 cm), and the minimum distance across the imaging lumen through the central axis of the imaging lumen is 0.026 inches (0.066 cm) or more.

[0012] In addition to or as an alternative to any embodiment disclosed herein, the wall thickness of the catheter shaft at all locations along the catheter shaft is at least 0.003 inches (0.008 cm).

[0013] Another embodiment is a recanalization catheter for facilitating re-entry into the lumen of a vessel from the subintima-space of the vessel wall having an occlusion within it. The recanalization catheter includes a catheter shaft extending distally from a hub and an inflatable balloon positioned in the distal end region of the catheter shaft. The catheter shaft is an extruded tubular member defining a guidewire lumen extending through it, an expansion lumen that is in fluid communication with the interior of the inflatable balloon, and an imaging lumen extending through the catheter shaft configured to receive an IVUS imaging device.

[0014] In addition to or as an alternative to any embodiment disclosed herein, the re-canalization catheter further includes an IVUS imaging device positioned within the imaging lumen such that the IVUS transducer of the IVUS imaging device is located distal to an expandable balloon.

[0015] In addition to or as an alternative to any embodiment disclosed herein, the re-cancellation catheter further includes a lateral opening communicating with a guidewire lumen. The lateral opening opens to the outside of the catheter shaft between the proximal and distal ends of the inflatable balloon.

[0016] In addition to or as an alternative to any embodiment disclosed herein, the expansion lumen includes a first expansion lumen that is in fluid communication with a first inflatable balloon member of the expandable balloon, and a second expansion lumen that is in fluid communication with a second inflatable balloon member of the expandable balloon. In the proximal portion of the catheter shaft, the central longitudinal axis of the catheter shaft passes through the imaging lumen, and the entirety of the first expansion lumen, the second expansion lumen, and the guidewire lumen are located on the first side of a first virtual plane that extends parallel to and passes through the central longitudinal axis.

[0017] In addition to or as an alternative to any embodiment disclosed herein, in the distal portion of the catheter shaft, the imaging lumen and guidewire lumen are positioned between the first and second expansion lumen such that a second virtual plane extending parallel to and passing through the central longitudinal axis passes through the first expansion lumen, the second expansion lumen, the imaging lumen, and the guidewire lumen, respectively.

[0018] Another embodiment is a recanalization catheter for facilitating re-entry into the lumen of a blood vessel from the subintima-space of the wall of the blood vessel having an occlusion therein. The recanalization catheter includes a catheter shaft extending distally from a hub and an inflatable balloon positioned in the distal end region of the catheter shaft, the inflatable 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 substantially rectangular cross-sectional shape. The catheter shaft defines a guidewire lumen extending through an extruded proximal tubular member and an extruded distal tubular member, a first expansion lumen extending through the extruded proximal tubular member and the extruded distal tubular member, a second expansion 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 expansion lumen is in fluid communication with the interior of a first inflatable balloon member, and the second expansion lumen is in fluid communication with the interior of a second inflatable balloon member. The imaging lumen is configured to receive an IVUS imaging device therein.

[0019] In addition to or as an alternative to any embodiment disclosed herein, the re-cancellation catheter further includes a lateral opening communicating with a guidewire lumen. The lateral opening opens to the outside of the catheter shaft between a first inflatable balloon member and a second inflatable balloon member.

[0020] In addition to or alternative to any embodiments disclosed herein, the re-canalization catheter further includes an IVUS imaging device positioned within the imaging lumen such that the IVUS transducer of the IVUS imaging device is located distal to the lateral opening, preferably distal to the inflatable balloon.

[0021] In addition to or as an alternative to any embodiment disclosed herein, the central longitudinal axis of the catheter shaft passes through the imaging lumen throughout the entire extruded proximal tubular member, and the entirety of the first expansion lumen, the second expansion lumen, and the guidewire lumen are positioned on the first side of a first virtual plane that extends parallel to and passes through the central longitudinal axis.

[0022] In addition to or as an alternative to any embodiment disclosed herein, throughout the entire extruded distal tubular member, the imaging lumen and guidewire lumen are positioned between the first and second expansion lumen such that a second virtual plane extending parallel to and passing through the central longitudinal axis passes through the first expansion lumen, the second expansion lumen, the imaging lumen, and the guidewire lumen, respectively.

[0023] Another embodiment is a re-opening catheter for facilitating re-entry into the lumen of a vessel having an occlusion within it, from the subintima-space of the vessel wall. The catheter may include an elongated catheter shaft having a guidewire lumen and an imaging lumen extending therein. The distal end region of the catheter shaft may include a lateral opening communicating with the guidewire lumen. The catheter shaft may include reinforcing structures such as braids or coils to facilitate torque transmission of the catheter shaft, thereby allowing the lateral opening to rotate and orient toward the true lumen of the vessel distal to the occlusion. The re-entry device may be advanced through the guidewire lumen, exit through the lateral opening, and re-enter the true lumen distal to the occlusion. The imaging lumen is configured to receive an IVUS imaging device. The IVUS imaging device is configured to provide an ultrasound image of the vessel to confirm the rotational orientation of the lateral opening in the subintima-space and / or the trajectory of the re-entry device toward the true lumen from the lateral opening.

[0024] The above summary of some exemplary embodiments is not intended to describe all implementations of each disclosed embodiment or aspect of this disclosure.

Brief Description of the Drawings

[0025] [Figure 1] It is a perspective view of an exemplary catheter for vascular recanalization. [Figure 2A] It is a cross-sectional view along line 2-2 of the catheter shaft of the catheter of FIG. 1. [Figure 2B] It is an alternative cross-sectional view along line 2-2 of the catheter shaft of the catheter of FIG. 1. [Figure 2C] It is an alternative cross-sectional view along line 2-2 of the catheter shaft of the catheter of FIG. 1. [Figure 2D] It is an alternative cross-sectional view along line 2-2 of the catheter shaft of the catheter of FIG. 1. [Figure 3] It is a cross-sectional view along line 3-3 of the catheter shaft of the catheter of FIG. 1. [Figure 4] It is a cross-sectional view along line 4-4 of the catheter shaft of the catheter of FIG. 1. [Figure 5] It is a longitudinal cross-sectional view of the distal end region of the catheter of FIG. 1. [Figure 6] It shows an exemplary method aspect for recanalizing an occluded blood vessel using the catheter of FIG. 1. [Figure 7] It shows an exemplary method aspect for recanalizing an occluded blood vessel using the catheter of FIG. 1. [Figure 8] It shows an exemplary method aspect for recanalizing an occluded blood vessel using the catheter of FIG. 1. [Figure 9] It shows an exemplary method aspect for recanalizing an occluded blood vessel using the catheter of FIG. 1. [Figure 10] It shows an exemplary method aspect for recanalizing an occluded blood vessel using the catheter of FIG. 1. [Figure 11] It is a plan view of an exemplary catheter for vascular recanalization. [Figure 12] It is a cross-sectional view of the catheter shaft of the catheter of FIG. 11 along line 12-12 of FIG. 11. [Modes for carrying out the invention]

[0026] Aspects of this disclosure may be better understood by considering the following detailed description of various embodiments in relation to the accompanying drawings. While various modifications and alternative forms are acceptable for the aspects of this disclosure, their details are illustrated and described in detail in the drawings. However, it should be understood that the intent is not to limit the aspects of this disclosure to the specific embodiments described. On the contrary, the intent is to encompass all modifications, equivalents, and alternative forms that fall within the spirit and scope of this disclosure.

[0027] The terms defined below shall apply unless otherwise given in the claims or elsewhere in this specification. All numerical values ​​herein are assumed to be modified by the term “about,” whether expressly indicated or not. The term “about” generally refers to a range of numbers that a person skilled in the art would consider equivalent to (i.e., having the same function or result as) the cited value. Often, the term “about” may be indicated as a number rounded to the nearest significant figure.

[0028] A numerical range referenced by an endpoint includes all numbers within that range (for example, 1-5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). While several appropriate dimensions, ranges, and / or values ​​relating to various components, features, and / or specifications are disclosed, a person skilled in the art, as referenced by this disclosure, will understand that desired dimensions, ranges, and / or values ​​may deviate from those expressly disclosed.

[0029] As used herein and in the appended claims, the singular forms “a,” “an,” and “the” refer to multiple subjects unless the context clearly indicates otherwise. As used herein and in the appended claims, the term “or” is generally used to include “and / or” unless the context clearly indicates otherwise.

[0030] The following detailed description should be read with reference to the drawings, where similar elements in different drawings are numbered the same. The detailed description and drawings are illustrative embodiments and are not necessarily to a specific scale, and are not intended to limit the scope of this disclosure. The exemplary embodiments shown are intended for illustrative purposes only. Selected features of any exemplary embodiment may be incorporated into additional embodiments unless otherwise expressly stated.

[0031] An exemplary recanalization catheter 10 is shown in Figure 1. The recanalization catheter 10 may include a catheter shaft 12 extending from a hub assembly 14 at the proximal end 16 of the catheter shaft 12 to an inflatable balloon 20 attached to the distal end region 18 of the catheter shaft 12. The distal end region 18 of the catheter shaft 12 may extend through the inflatable balloon 20 and form a distal tip portion 22 extending distal to the inflatable balloon 20. In some examples, as further described herein, the inflatable balloon 20 may be formed from one or more inflatable balloon members 20a, 20b that can be inflated using an expansion fluid delivered through an expansion lumen 26 (see Figures 2A-2D) of the catheter shaft 12, as further described herein.

[0032] The catheter 10 may be configured to advance along a guidewire for delivery to a remote location within the patient's vascular system. For example, in some examples, the catheter 10 may be configured as an over-the-wire (OTW) catheter having a guidewire lumen 24 (see Figures 2A-2D) that extends along the entire length of the catheter 10 from a distal opening 28 at the distal tip 22 of the catheter 10 to a proximal guidewire port 30 in the hub assembly 14. The distal opening 28 may be located in the most distal range of the catheter 10. In other examples, the catheter 10 may be configured as a single-operator exchange (SOE) catheter having a guidewire lumen 24 that extends from the distal opening 28 to a proximal guidewire port (not shown) located at a short distance proximal to the inflatable balloon 20 and distal to the hub assembly 14. In such a configuration, the guidewire may extend through the guidewire lumen 24 between the distal opening 28 and the proximal guidewire port, and may extend along the outside of the catheter shaft 12 proximal to the proximal end 16 of the catheter shaft 12. Note that if the catheter 10 is an SOE type catheter, the hub assembly 14 may not include the proximal guidewire port 30.

[0033] The re-drainage catheter 10 may include and / or house an intravascular ultrasound (IVUS) imaging device 200. The IVUS imaging device 200 may include an elongated shaft 202 extending distally from the hub 202. The IVUS imaging device 200 may also include a flush port 206 in some examples. The IVUS imaging device 200 may be coupled to, extend from, and / or received by the port 36 so that the elongated shaft 202 of the IVUS imaging device 200 can be positioned through the imaging lumen (described later) of the catheter shaft 12.

[0034] Referring to Figure 2A, a cross-sectional view of the catheter shaft 12 along line 2-2 in Figure 1, the catheter shaft 12 or a portion thereof may be an extruded shaft having a plurality of lumens formed therein. For example, the proximal portion of the catheter shaft 12 may include a guidewire lumen 24 extending through it, an expansion lumen 26 (shown as a branched lumen including a first expansion lumen 26a and a second expansion lumen 26b extending parallel to the first expansion lumen 26a and separated from the first expansion lumen 26a), and one or more auxiliary lumens. For example, the catheter shaft 12 may include an imaging lumen 32 configured to house an intravascular ultrasound (IVUS) device. The guidewire lumen 24 may extend to the distal tip 18 of the catheter shaft 12, while the expansion lumen 26 may extend into the interior of an expandable balloon 20 from a proximal expansion port 34 in a hub assembly 14. For example, the first expansion lumen 26a can be in fluid communication with the first inflatable balloon member 20a, and the second expansion lumen 26b can be in fluid communication with the second inflatable balloon member 20b. The first expansion lumen 26a may converge with the second expansion lumen 26a when the expansion lumen 26 extends to the proximal expansion port 34. The imaging lumen 32 extends distally from the proximal port 36 through the catheter shaft 12 to the inflatable balloon 20 and / or beyond the inflatable balloon 20. In some examples, the imaging lumen 32 may extend to the distal tip 22, while in other examples, the imaging lumen 32 may terminate proximal to the distal tip 18 of the catheter shaft 12. For example, in some examples, the distal termination point of the imaging lumen 32 may be located along the longitudinal length of the inflatable balloon 20.

[0035] As shown in Figure 2A, the proximal region of the catheter shaft 12 may have a circular cross-section with an outer diameter D1 of approximately 0.059 inches (0.150 cm). In some examples, the outer diameter D1 may be, for example, less than or equal to approximately 0.06 inches (0.152 cm), less than or equal to approximately 0.055 inches (0.140 cm), or less than or equal to approximately 0.052 inches (0.132 cm). In some examples, the outer diameter D1 may be, for example, approximately 0.059 inches (0.150 cm), less than or equal to approximately 0.055 inches (0.140 cm), less than or equal to approximately 0.052 inches (0.132 cm), or less than or equal to approximately 0.050 inches (0.127 cm). The outer diameter D1 is such that the catheter shaft 12 of the catheter 10 has an outer diameter of, for example, approximately 0.026 inches (0.066 cm), Boston The size may be determined so that it can be positioned in parallel with a capture balloon catheter such as the Trapper® Device commercially available from Scientific Corp., within a 6F (2 mm) guide catheter having an inner lumen diameter of approximately 0.07 inches (0.178 cm), such as in the range of approximately 0.070 inches (0.178 cm) to approximately 0.072 inches (0.183 cm); within a 7F (2.33 mm) guide catheter having an inner lumen diameter of approximately 0.08 inches (0.203 cm), such as in the range of approximately 0.78 inches (0.198 cm) to approximately 0.082 inches (0.208 cm); or within an 8F (2.67 mm) guide catheter having an inner lumen diameter of approximately 0.09 inches (0.229 cm), such as in the range of approximately 0.088 inches (0.224 cm) to approximately 0.091 inches (0.231 cm).

[0036] The guidewire lumen 24 may have a diameter D2 of approximately 0.017 inches (0.043 cm) to accommodate a 0.014 inch (0.036 cm) guidewire. The first expansion lumen 26a and the second expansion lumen 26b may each have a diameter D3 of, for example, approximately 0.0115 inches (0.0292 cm) or less, or approximately 0.0105 inches (0.0267 cm) or less. The imaging lumen 32 may be sized to accommodate an IVUS device, such as the OptiCross® Imaging Catheter commercially available from Boston Scientific, Corp., or its IVUS imaging core, while also providing space for fluid aspiration passing through it alongside the IVUS imaging device. The elongated shaft 202 of the imaging device 200 is shown positioned within the imaging lumen 32. For example, in some examples, the IVUS imaging device may have an outer diameter of approximately 0.025 inches (0.064 cm) or less. As shown in Figure 2A, where the outer diameter D1 is approximately 0.059 inches (0.150 cm), the imaging tube lumen 32 may have a non-circular cross-section, shown as an elliptical cross-section with a secondary radius R1 of approximately 0.0165 inches (0.0419 cm) and a principal radius R2 of approximately 0.0212 inches (0.0538 cm). Thus, the imaging tube lumen 32 has a distance of approximately 0.0330 inches (0.0838 cm) along its minor axis, a distance of approximately 0.0424 inches (0.1077 cm) along its major axis, and a diameter of approximately 0.00110 square inches (0.00710 cm). 2 ) provides an area of ​​approximately 0.1189 inches (0.3020 cm) and a perimeter of approximately 0.1189 inches (0.3020 cm). In other examples, such as when the outer diameter D1 is approximately 0.052 inches (0.132 cm), the imaging tube lumen 32 may have an elliptical cross-section with a minor radius R1 of approximately 0.0130 inches (0.0330 cm) and a major radius R2 of approximately 0.0175 inches (0.0445 cm), and thus a distance of approximately 0.026 inches (0.066 cm) along its minor axis, a distance of approximately 0.035 inches (0.089 cm) along its major axis, and a perimeter of approximately 0.0007147 square inches (0.0046110 cm). 2The imaging lumen 32 is provided having an area of ​​) and a circumference of approximately 0.09634 inches (0.24470 cm). The lumen may be sized such that the thickness T of the catheter wall is at least 0.003 inches (0.008 cm) at all locations on the catheter shaft 12. In other examples, the lumen may be sized such that the thickness T of the catheter wall is, for example, at least 0.002 inches (0.005 cm), at least 0.0024 inches (0.0061 cm), at least 0.0026 inches (0.0066 cm), or at least 0.0028 inches (0.0071 cm) at all locations on the catheter shaft 12.

[0037] As shown in Figure 2A, the guidewire lumen 24 may have a larger cross-sectional area than the cross-sectional areas of the first and second expansion lumen 26, and the imaging lumen 32 may have a larger cross-sectional area than the guidewire lumen 24. However, other configurations are also conceivable.

[0038] In some examples, such as the embodiment shown in Figure 2A, the guidewire lumen 24 may be positioned between the first expansion lumen 26a and the second expansion lumen 26b. The guidewire lumen 24 may be equally spaced between the first expansion lumen 26a and the second expansion lumen 26b, with the wall thickness of the catheter shaft between them being at least about 0.002 inches (0.005 cm) or at least about 0.003 inches (0.008 cm). As shown in Figure 2A, the catheter shaft 12 may be constructed such that the guidewire lumen 24, the first expansion lumen 26a, and the second expansion lumen 26b are all parallel to the central longitudinal axis X of the catheter shaft 12 and are positioned entirely on one side of the plane Y passing through the central longitudinal axis X. The imaging tube lumen 32 can be positioned such that the central longitudinal axis X of the catheter shaft 12 is located within the imaging tube lumen 32, and the majority of the cross-sectional area of ​​the imaging tube lumen 32 is located on the opposite side of the plane Y that is parallel to and passes through the central longitudinal axis X.

[0039] Furthermore, as shown in Figure 2A, the catheter shaft 12 may be constructed such that a plane Z extending parallel to the central longitudinal axis X and passing through the central longitudinal axis X passes through the centers of the guidewire lumen 24 and the imaging lumen 32, respectively. In some examples, plane Z may be perpendicular to plane Y. The first expansion lumen 26a may be located on the first side of plane Z, and the second expansion lumen 26b may be located on the second side of plane Z. In some examples, the first and second expansion lumen 26a, 26b may be equidistant from plane Z.

[0040] Figure 2B shows an alternative cross-sectional view of the proximal portion of the catheter shaft 12 along line 2-2 in Figure 1. The outer diameter D1, as well as the size, shape, configuration, and position of the guidewire lumen 24 and the first and second expansion lumens 26a, 26b, may be the same as those described above with respect to Figure 2A. The imaging lumen 32 may be sized to accommodate an IVUS device, such as the OptiCross® Imaging Catheter commercialized by Boston Scientific, Corp., or its IVUS imaging core, while also providing space for fluid aspiration passing through it alongside the IVUS imaging device. The elongated shaft 202 of the imaging device 200 is shown positioned within the imaging lumen 32. For example, in some examples, the IVUS imaging device may have an outer diameter of approximately 0.025 inches (0.064 cm) or less. As shown in Figure 2B, where the outer diameter D1 is approximately 0.059 inches (0.150 cm), the imaging tube lumen 32 may have a non-circular cross-section, shown as an oblong cross-section with a secondary radius R1 of approximately 0.0165 inches (0.0419 cm) and a principal radius R2 exceeding 0.0212 inches (0.0538 cm). Thus, the imaging tube lumen 32 has a distance of approximately 0.0330 inches (0.0838 cm) along its minor axis, a distance of more than 0.043 inches along its major axis, and a diameter of approximately 0.00119 square inches (0.00768 cm). 2) provides an area of ​​approximately 0.00081 square inches (0.00523 cm) and a perimeter of approximately 0.1270 inches (0.3226 cm). In other examples, such as when the outer diameter D1 is approximately 0.052 inches (0.132 cm), the imaging lumen 32 may have an oval cross-section with a secondary radius R1 of approximately 0.0130 inches (0.0330 cm) and a principal radius R2 greater than 0.0175 inches (0.0445 cm), and thus the imaging lumen 32 has a distance of approximately 0.026 inches (0.066 cm) along its minor axis and a distance of approximately 0.035 inches (0.089 cm) along its major axis, and an area of ​​approximately 0.00081 square inches (0.00523 cm). 2 The lumen provides an area of ​​) and a circumference of approximately 0.1064 inches (0.2702 cm). The lumen may be sized such that the thickness T of the catheter wall is at least 0.003 inches (0.008 cm) at all points along the catheter shaft 12. In other examples, the lumen may be sized such that the thickness T of the catheter wall is, for example, at least 0.002 inches (0.005 cm), at least 0.0024 inches (0.0061 cm), at least 0.0026 inches (0.0066 cm), or at least 0.0028 inches (0.0071 cm) at all points along the catheter shaft 12.

[0041] As shown in Figure 2B, the guidewire lumen 24 may have a larger cross-sectional area than the cross-sectional areas of the first and second expansion lumen 26, and the imaging lumen 32 may have a larger cross-sectional area than the guidewire lumen 24. However, other configurations are also conceivable.

[0042] As shown in Figure 2B, the catheter shaft 12 may be constructed such that the guidewire lumen 24, the first expansion lumen 26a, and the second expansion lumen 26b are each parallel to the central longitudinal axis X of the catheter shaft 12 and are positioned entirely on one side of the plane Y passing through the central longitudinal axis X. The imaging lumen 32 can be positioned such that the central longitudinal axis X of the catheter shaft 12 is within the imaging lumen 32, and the majority of the cross-sectional area of ​​the imaging lumen 32 is positioned parallel to the central longitudinal axis X and on the opposite side of the plane Y passing through the central longitudinal axis X.

[0043] Furthermore, as shown in Figure 2B, the catheter shaft 12 may be constructed such that a plane Z extending parallel to the central longitudinal axis X and passing through the central longitudinal axis X passes through the centers of the guidewire lumen 24 and the imaging lumen 32, respectively. In some examples, plane Z may be perpendicular to plane Y. The first expansion lumen 26a may be located on the first side of plane Z, and the second expansion lumen 26b may be located on the second side of plane Z. In some examples, the first and second expansion lumen 26a, 26b may be equidistant from plane Z.

[0044] Figure 2C shows an alternative cross-sectional view of the proximal portion of the catheter shaft 12 along line 2-2 in Figure 1. The proximal region of the catheter shaft 12 may have a circular cross-section with an outer diameter D1 of, for example, about 0.052 inches (0.132 cm). In some examples, the outer diameter D1 may be, for example, less than or equal to about 0.06 inches (0.152 cm), less than or equal to about 0.055 inches (0.140 cm), or less than or equal to about 0.052 inches (0.132 cm). In some examples, the outer diameter D1 may be, for example, about 0.059 inches (0.150 cm), less than or equal to 0.055 inches (0.140 cm), less than or equal to 0.052 inches (0.132 cm), or less than or equal to 0.050 inches (0.127 cm). The outer diameter D1 may be sized so that the catheter shaft 12 of the catheter 10 can be positioned in parallel with a capture balloon catheter such as the Trapper® Exchange Device, commercially available from Boston Scientific, Corp., which has an outer diameter of approximately 0.026 inches (0.066 cm), within a 6F (2 mm) guide catheter having an inner lumen diameter of approximately 0.070 inches (0.178 cm), within a 7F (2.33 mm) guide catheter having an inner lumen diameter of approximately 0.078 inches (0.198 cm), or within an 8F (2.67 mm) guide catheter having an inner lumen diameter of approximately 0.088 inches (0.224 cm).

[0045] The guidewire lumen 24 may have a diameter D2 of approximately 0.017 inches (0.043 cm) to accommodate a 0.014 inch (0.036 cm) guidewire. The catheter shaft 12 may have a single expansion lumen 26 having a diameter D3 of, for example, approximately 0.013 inches or less. The imaging lumen 32 may be sized to accommodate an IVUS device, such as the OptiCross® Imaging Catheter commercialized by Boston Scientific, Corp., or its IVUS imaging core, while also providing space for fluid aspiration passing through it alongside the IVUS imaging device. The elongated shaft 202 of the imaging device 200 is shown positioned within the imaging lumen 32. For example, in some examples, the IVUS imaging device may have an outer diameter of approximately 0.025 inches (0.064 cm) or less. As shown in Figure 2C, with an outer diameter D1 of approximately 0.052 inches (0.132 cm), the imaging lumen 32 may have an elliptical cross-section with a secondary radius R1 of approximately 0.0125 inches and a principal radius R2 of approximately 0.017 inches (0.043 cm), thus providing the imaging lumen 32 with a distance of approximately 0.025 inches (0.064 cm) along its minor axis, a distance of approximately 0.034 inches along its major axis, an area of ​​approximately 0.0006676 square inches (0.004307 cm²), and a perimeter of approximately 0.09322 inches. In other examples, such as when the outer diameter D1 is approximately 0.059 inches (0.150 cm), the imaging tube lumen 32 may have a non-circular cross-section, shown as an elliptical cross-section with a minor radius R1 of approximately 0.0165 inches (0.0419 cm) and a major radius R2 of approximately 0.0212 inches (0.0538 cm), and thus a distance of approximately 0.0330 inches (0.0838 cm) along its minor axis, a distance of approximately 0.0424 inches (0.1077 cm) along its major axis, and a distance of approximately 0.00110 square inches (0.00710 cm). 2The imaging lumen 32 is provided having an area of ​​) and a circumference of approximately 0.1189 inches (0.3020 cm). The lumen may be sized such that the catheter wall thickness T is at least 0.003 inches (0.008 cm) at all locations on the catheter shaft 12. In other examples, the lumen may be sized such that the catheter wall thickness T is, for example, at least 0.002 inches (0.005 cm), at least 0.0024 inches (0.0061 cm), at least 0.0026 inches (0.0066 cm), or at least 0.0028 inches (0.0071 cm) at all locations on the catheter shaft 12.

[0046] As shown in Figure 2C, the guidewire lumen 24 may have a larger cross-sectional area than the expansion lumen 26, and the imaging lumen 32 may have a larger cross-sectional area than the guidewire lumen 24. However, other configurations are also conceivable.

[0047] As shown in Figure 2C, the catheter shaft 12 may be constructed such that the guidewire lumen 24 and the expansion lumen 26 are both parallel to the central longitudinal axis X of the catheter shaft 12 and are positioned entirely on one side of the plane Y passing through the central longitudinal axis X. The imaging lumen 32 can be positioned such that the central longitudinal axis X of the catheter shaft 12 is within the imaging lumen 32, and the majority of the cross-sectional area of ​​the imaging lumen 32 is positioned parallel to the central longitudinal axis X and on the opposite side of the plane Y passing through the central longitudinal axis X.

[0048] Figure 2D shows an alternative cross-sectional view of the proximal portion of the catheter shaft 12 along line 2-2 in Figure 1. The proximal region of the catheter shaft 12 may have a circular cross-section with an outer diameter D1 of, for example, about 0.059 inches (0.150 cm). In some examples, the outer diameter D1 may be, for example, less than or equal to about 0.06 inches (0.152 cm), less than or equal to about 0.055 inches (0.140 cm), or less than or equal to about 0.052 inches (0.132 cm). In some examples, the outer diameter D1 may be, for example, about 0.059 inches (0.150 cm), less than or equal to 0.055 inches (0.140 cm), less than or equal to 0.052 inches (0.132 cm), or less than or equal to 0.050 inches (0.127 cm). The outer diameter D1 may be sized so that the catheter shaft 12 of the catheter 10 can be positioned alongside a capture balloon catheter, such as a Trapper® Exchange Device commercially available from Boston Scientific, Corp., which has an outer diameter of approximately 0.026 inches (0.066 cm), within a 6F (2 mm) guide catheter with an inner lumen diameter of approximately 0.070 inches (0.178 cm), within a 7F (2.33 mm) guide catheter with an inner lumen diameter of approximately 0.078 inches (0.198 cm), or within an 8F (2.67 mm) guide catheter with an inner lumen diameter of approximately 0.088 inches (0.224 cm).

[0049] The guidewire lumen 24 may have a diameter D2 of approximately 0.017 inches (0.043 cm) to accommodate a 0.014 inch (0.036 cm) guidewire. The first expansion lumen 26a and the second expansion lumen 26b may each have a diameter D3 of, for example, approximately 0.0115 inches (0.0292 cm) or less, or approximately 0.0105 inches (0.0267 cm) or less. The imaging lumen 32 may be sized to accommodate an IVUS device such as the OptiCross® Imaging Catheter, commercially available from Boston Scientific, Corp., or its IVUS imaging core. The elongated shaft 202 of the imaging device 200 is shown positioned within the imaging lumen 32. For example, in some examples, the IVUS imaging device may have an outer diameter of approximately 0.025 inches (0.064 cm) or less. As shown in Figure 2D, with an outer diameter D1 of approximately 0.059 inches (0.150 cm), the imaging lumen 32 may have a circular cross-section with a radius of approximately 0.0125 inches (0.032 cm) (a diameter of approximately 0.025 inches (0.064 cm)). The catheter shaft 12 may include additional lumens, such as a suction lumen 38, which extends parallel to and is separated from the imaging lumen 32. In some embodiments, the suction lumen 38 may have a circular cross-section. In an embodiment where the outer diameter D1 is approximately 0.059 inches (0.150 cm), the suction lumen 38 may have a radius of approximately 0.01125 inches (a diameter of approximately 0.0225 inches). The lumen may be sized such that the catheter wall thickness T is at least 0.003 inches (0.008 cm) at all locations on the catheter shaft 12. In other examples, the lumen may be sized such that the thickness T of the catheter wall is, for example, at least 0.002 inches (0.005 cm), at least 0.0024 inches (0.0061 cm), at least 0.0026 inches (0.0066 cm), or at least 0.0028 inches (0.0071 cm) at all points along the catheter shaft 12.

[0050] As shown in Figure 2D, the guidewire lumen 24 may have a larger cross-sectional area than the cross-sectional areas of the first and second expansion lumen 26, and the imaging lumen 32 may have a larger cross-sectional area than the guidewire lumen 24. The suction lumen 38 may have a cross-sectional area larger or smaller than the cross-sectional area of ​​the guidewire lumen 24 and / or the imaging lumen 32. However, other configurations are also conceived.

[0051] As shown in Figure 2D, the catheter shaft 12 may be configured such that the guidewire lumen 24 and the first and second expansion lumens 26a, 26b are each parallel to the central longitudinal axis X of the catheter shaft 12 and are positioned entirely on one side of the plane Y passing through the central longitudinal axis X. The imaging lumen 32 and suction lumen 38 may be positioned such that the plane Y passes through the imaging lumen 32 and suction lumen 38, respectively, and that the majority of the cross-sectional area of ​​the imaging lumen 32 and the majority of the cross-sectional area of ​​the suction lumen 38 are positioned on the opposite side of the plane Y that is parallel to and passes through the central longitudinal axis X.

[0052] Referring to Figure 3, a cross-sectional view of the catheter shaft 12 along line 3-3 in Figure 1, 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 expansion lumen 26 (shown as a branched lumen, including a first expansion lumen 26a and a second expansion lumen 26b extending parallel to and spaced apart from the first expansion lumen 26b), and one or more auxiliary lumens extending through it. For example, the distal portion of the catheter shaft 12 may include an imaging lumen 32 configured to house an intravascular ultrasound (IVUS) imaging device and / or a suction lumen (see Figure 2D). The elongated shaft 202 of the imaging device 200 is shown positioned within the imaging lumen 32.

[0053] The cross-sectional shape of the catheter shaft 12 in the distal portion may differ from the cross-sectional shape of the catheter shaft 12 in the proximal portion. For example, as described above with respect to Figures 2A to 2D, the proximal portion of the catheter shaft 12 may have a circular cross-sectional shape, while the distal portion of the catheter shaft 12 may have a non-circular cross-sectional shape, such as a roughly rectangular cross-sectional shape.

[0054] The positions and arrangements of the various lumens in the proximal portion of the catheter shaft 12 may differ from those in the distal portion of the catheter shaft 12. For example, in the distal portion of the catheter shaft 12, the first and second expansion lumens 26a and 26b may be positioned on either side of the imaging lumen 32 and the guidewire lumen 24, with the imaging lumen 32 and the guidewire lumen 24 positioned between the first and second expansion lumens 26a and 26b. The imaging lumen 32, the guidewire lumen 24, and the first and second expansion lumens 26a and 26b may be positioned such that a plane Y extending parallel to and passing through the central longitudinal axis X of the catheter shaft 12 passes through the imaging lumen 32, the guidewire lumen 24, and the first and second expansion lumens 26a and 26b, respectively (e.g., they may be aligned). In some examples, plane Y may pass through the center or near the center of the imaging tube lumen 32 and the guidewire lumen 24, respectively.

[0055] The overall width W of the distal portion of the catheter shaft 12, measured parallel to the plane Y, may be, for example, approximately 0.07 inches (0.18 cm) or less, approximately 0.068 inches (0.173 cm) or less, 0.066 inches (0.168 cm) or less, or 0.065 inches (0.165 cm) or less. The overall height H of the distal portion of the catheter shaft 12, measured perpendicular to the width W, may be, for example, approximately 0.035 inches (0.089 cm) or less, approximately 0.033 inches (0.084 cm) or less, or approximately 0.032 inches (0.081 cm) or less.

[0056] The guidewire lumen 24 may have a diameter D2 of approximately 0.017 inches (0.043 cm) to accommodate a 0.014 inch (0.036 cm) guidewire. The imaging lumen 32 may have a diameter D4 of approximately 0.026 inches (0.066 cm) to accommodate an IVUS imaging catheter. The first and second expansion lumens 26a, 26b, respectively, may have a width D5 of approximately 0.0037 inches (0.094 cm). The lumens may be sized such that the catheter wall thickness T is at least 0.003 inches (0.008 cm) at all points along the catheter shaft 12. In other examples, the lumen may be sized such that the thickness T of the catheter wall is, for example, at least 0.002 inches (0.005 cm), at least 0.0024 inches (0.0061 cm), at least 0.0026 inches (0.0066 cm), or at least 0.0028 inches (0.0071 cm) at all points along the catheter shaft 12.

[0057] The extruded proximal portion of the catheter shaft 12 may be joined to the extruded distal portion of the catheter shaft 12 such that the lumen of the proximal portion of the catheter shaft 12 communicates with the corresponding lumen of the distal portion of the catheter shaft 12. In other words, the aforementioned lumen may be continuous through the proximal and distal portions of the catheter shaft 12, and the cross-sectional shape of the proximal portion of the catheter shaft 12 may differ from the cross-sectional shape of the distal portion of the catheter shaft 12.

[0058] Refer to Figure 4, a cross-sectional view of the distal end region of the catheter shaft 12 along line 4-4 in Figure 1, including the inflatable balloon 20 of the catheter shaft 12. In some examples, the first and second inflatable balloon members 20a, 20b of the inflatable balloon 20 may be formed as a single or monolithic portion of the catheter shaft 12. However, in other examples, the first and second inflatable balloon members 20a, 20b of the inflatable balloon 20 may be formed separately and then fixed to the catheter shaft 12. As shown in Figure 4, the first inflatable lumen 26a may open into the interior of the first inflatable balloon member 20a, and the second inflatable lumen 26b may open into the interior of the second inflatable balloon member 20b.

[0059] The overall width W1 of the inflatable balloon 20, including both the first and second inflatable balloon members 20a and 20b, measured parallel to the plane Y, may be approximately 0.142 inches (0.361 cm) when inflated. In some cases, the overall width W1 may be, for example, approximately 0.14 inches (0.36 cm) or more, approximately 0.16 inches (0.41 cm) or more, approximately 0.18 inches (0.46 cm) or more, approximately 0.20 inches (0.51 cm) or more, approximately 0.14 inches (0.36 cm), approximately 0.16 inches (0.41 cm), approximately 0.18 inches (0.46 cm), approximately 0.20 inches (0.51 cm), in the range of approximately 0.14 inches (0.36 cm) to approximately 0.20 inches (0.51 cm), or in the range of approximately 0.16 inches (0.41 cm) to approximately 0.22 inches (0.56 cm). The overall height H1 of the inflatable balloon 20, measured perpendicular to its width W1 (for example, the height of either the first and / or second inflatable balloon member 20a, 20b), may be, for example, about 0.023 inches (0.058 cm) when inflated. Therefore, the width of the inflatable balloon 20 may be greater than its height when inflated. For example, when inflated, the inflatable balloon 20 may have a width-to-height ratio of 2:1 or greater, 3:1 or greater, 4:1 or greater, 5:1 or greater, or 6:1 or greater.

[0060] The distal region of the elongated shaft 12 may also include a first lateral opening 50 that opens to the outside of the catheter shaft 12 between the first inflatable balloon member 26a and the second inflatable balloon member 26b. In some examples, the distal region of the elongated shaft 12 may also include a second lateral opening 52 (see also Figure 5) that opens to the outside 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 may communicate with the guidewire lumen 24. Each of the first lateral opening 50 and the second lateral opening 52 may extend through the side wall of the catheter shaft 12. For example, the first lateral opening 50 may extend through the side wall of the catheter shaft 12 on the first side exposed between the first inflatable balloon member 26a and the second inflatable balloon member 26b, and the second lateral opening 52 may extend through the side wall of the catheter shaft 12 on the opposite second side exposed between the first inflatable balloon member 26a and the second inflatable balloon member 26b.

[0061] Each of the first lateral opening 50 and the second lateral opening 52 may be configured to allow a re-entry device or penetrating member to advance from there during a re-draining procedure, puncturing the subintima space into the true lumen of the vessel through the tissue layer of the vessel wall. For example, the distal portion of the re-entry device or penetrating member may be advanced through the guidewire lumen 24, passing laterally from the catheter shaft 12 and exiting through either the first lateral opening 50 or the second lateral opening 52, penetrating the tissue layer of the vessel.

[0062] As shown in Figure 5, in some examples, the first lateral opening 50 may be located in the distal region of the catheter shaft 12, between the proximal and distal ends of the inflatable balloon 20, for example, between the proximal and distal ends of the first and second inflatable balloon members 20a, 20b. In addition, the second lateral opening 52 may be located in the distal region of the catheter shaft 12, between the proximal and distal ends of the inflatable balloon 20, for example, between the proximal and distal ends of the first and second inflatable balloon members 20a, 20b. In other examples, the first lateral opening 50 and / or the second lateral opening 52 may be located in the distal region of the catheter shaft 12, such as proximal to the proximal end of the inflatable balloon 20 or distal to the distal end of the inflatable balloon 20. The first lateral opening 50 and the second lateral opening 52 may be longitudinally offset from each other along the catheter shaft 12 (i.e., axially separated). For example, the first lateral opening 50 may be located proximal to the second lateral opening 52. The catheter shaft 12 may also include a radiopaque marker 51 located close to the first lateral opening 50 to indicate its location under fluoroscopy. In addition, the catheter shaft 12 may include a radiopaque marker 53 located close to the second lateral opening 52 to indicate its location under fluoroscopy.

[0063] Figure 5 also shows a guidewire 100 positioned within the guidewire lumen 24 of the catheter shaft 12, and an IVUS imaging device 200 (e.g., an IVUS imaging catheter or core) positioned within the imaging lumen 32 of the catheter shaft 12, with an ultrasound transducer 210 at its distal end. The IVUS imaging device 200 may be longitudinally movable within the imaging lumen 32 so that it can be advanced distally and retracted proximal to the catheter shaft 12, allowing the ultrasound transducer 210 to be positioned at a desired location within the imaging lumen 32 during medical procedures. In other examples, the IVUS imaging device 200 may be fixed so as not to move longitudinally within the imaging lumen 32. In some embodiments, the ultrasonic transducer 210 may be positioned or can be positioned distal to the first lateral opening 50, distal to the second lateral opening 52, and / or distal to the inflatable balloon 20, so that the imaging device can provide an ultrasonic image of the trajectory of the re-entry device from the catheter shaft 12.

[0064] In some cases, using medical devices to pass through an occlusion, such as a chronic total occlusion (CTO) in the lumen of a blood vessel, to recanalize the vessel may be undesirable, difficult, or impossible. In such cases, it is possible to recanalize the vessel by a subintima approach using a catheter 10. As further described herein, the catheter 10 may be configured to facilitate re-entry into the true lumen of the vessel distal to the occlusion (e.g., chronic total occlusion) from a subintima space formed in the vessel wall that bypasses the occlusion. For example, the distal portion of the catheter shaft 12, including the inflatable balloon 20, can be advanced into the subintima space (i.e., the space between the intima and adventitia) formed in the vessel wall of the vessel, such as by cutting the tissue layers of the vessel wall. Once positioned in the subintima space, the first and second inflatable balloon members 20a, 20b of the inflatable balloon 20 can be inflated into an expand / expand configuration between the intima and adventitia of the vessel wall. When the first and second balloon members 20a, 20b are inflated to their expansion / inflation configuration, they extend laterally from the catheter shaft 12 within the subintima-space formed in the vessel wall, automatically orienting either the first lateral opening 50 or the second lateral opening 52 radially inward toward the true lumen of the vessel. A re-entry device (e.g., a re-entry guidewire or other penetrating member) may be advanced through the guidewire lumen 24 and exit through one of the first lateral opening 50 or the second lateral opening 52 (either of which faces the true lumen), penetrating from a subintima-space through the intima-layer into the true lumen.

[0065] Referring to Figures 6 to 10, several embodiments of exemplary methods for recanalizing an occluded blood vessel 80 using a catheter 10 are shown. A blood vessel 80 typically has three tissue layers, namely the innermost or intima (i.e., the intima) 82, the intermediate or media (i.e., the media) 84, and the outermost or adventitia (adventitia) 86, with the media 84 situated between the intima 82 and the adventitia 86. The intima 82 is a layer of endothelial cells lining the lumen 88 of the blood vessel 80 and is a subendothelial layer composed mostly of loose connective tissue. The media 84 is a muscular layer formed mainly of circumferentially arranged smooth muscle cells. The adventitia 86, which forms the outer layer of the blood vessel wall 80, is formed mainly of loose connective tissue composed of fibroblasts and associated collagen fibers.

[0066] As shown in Figure 6, the guidewire 100 may first be advanced through the lumen 88 of the blood vessel 80 to a position close to the proximal end of the occlusion 90 that blocks the lumen 88. Next, the guidewire 100 may be advanced by penetrating the intima 82 at a position proximal to the proximal end of the occlusion 90 and puncturing outward into the wall of the blood vessel 80. With the tip of the guidewire 100 positioned between the intima 82 and the adventitia 86, the guidewire 100 may be further advanced distally in a subintimal manner to create a subintimal space between the intima 82 and the adventitia 86. As shown in Figure 7, the guidewire 100 may be advanced in a subintimal manner until its distal tip is located distal to the distal end of the occlusion 90 in the subintimal space created by cutting the tissue layers of the wall of the blood vessel 80. In some cases, a separate catheter device may be used first to exit the lumen 88 proximal to the occlusion 90 and form a subintima. In such cases, the guidewire 100 may then be advanced through the catheter into the subintima, and the catheter may be retracted, leaving the guidewire 100 positioned in the subintima, as shown in Figure 7.

[0067] Next, as shown in Figure 8, the recanalization catheter 10 can be advanced distally along the guidewire 100 from the true lumen 88 proximal to the occlusion 90 to a position in the subintima-space between the intima-layer 82 and the adventitia 86, where the distal portion of the catheter 10, including the inflatable balloon 20, is located distal to the distal end of the occlusion 90. The recanalization catheter 10 can be advanced through the subintima-space in a delivery configuration such as a configuration in which the inflatable balloon 20 is deflated and folded.

[0068] 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 to the occlusion 90 to obtain an ultrasound image of the true lumen 88 and to confirm that the re-vector catheter 10 has advanced sufficiently beyond the occlusion 90, thereby enabling successful re-entry into the true lumen 88 using the re-entry device advanced from the re-vector catheter 10. The ultrasound transducer 210 may be positioned distal to the first lateral opening 50, the second lateral opening 52, and / or the inflatable balloon 20 so that the imaging device can provide an ultrasound image of the trajectory of the re-entry device from the catheter shaft 12. In some examples, the imaging device 200 can be advanced into the subintima space together with the catheter 10. In other examples, the imaging device 200 may be advanced through the imaging lumen 32 after the re-vector catheter 10 has been advanced into the subintima space.

[0069] In addition, when positioned within the subintima-vascular space, the first and second inflatable balloon members 20a and 20b of the inflatable balloon 20 can be inflated into an expanded / expanded configuration between the intima-vascular and adventitia layers of the vessel wall, as shown in Figure 10. The first and second inflatable balloon members 20a and 20b can be inflated before or after using the imaging device 200 to confirm the desired position of the re-opening catheter 10 distal to the occlusion 90. When the first and second balloon members 20a and 20b are inflated into the expanded / expanded configuration, they extend laterally from the catheter shaft 12 within the subintima-vascular space formed in the vessel wall, automatically orienting either 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 Figure 10, the expansion / inflation of the inflatable balloon members 20a, 20b may be performed by rotatably orienting the catheter shaft 12 to one of two possible orientations, either with the first lateral opening 50 facing the true lumen 88 of the blood vessel 80, or with the second lateral opening 52 facing the true lumen 88 of the blood vessel 80.

[0070] If necessary, blood in the subintimal space can be aspirated through the outside of the imaging lumen of the IVUS imaging device 200 (or through a separate suction lumen 38 if present) to reduce the pressure in the subintimal space and / or draw the intimal layer 86 against the catheter shaft 12. Aspiration of blood from the subintimal space can also prevent the collapse of the true lumen 88 distal to the occlusion 90.

[0071] The guidewire 100 is retracted from the guidewire lumen 24, and then the elongated re-entry device or penetrating member 120 is advanced through the guidewire lumen 24 of the catheter 10, and if the first lateral opening 50 faces the true lumen 88, it can exit through the first lateral opening 50 and penetrate through the intima layer 82 into the true lumen 88 distal to the occlusion 90, as shown in Figure 9. Note that if the expandable balloon 20 is inflated so that the catheter shaft 12 is oriented so that the second lateral opening 52 faces the true lumen 88, the elongated re-entry device or penetrating member 120 can be advanced through the guidewire lumen 24 of the catheter 10, exit through the second lateral opening 52, penetrate through the intima layer 82 and enter the true lumen 88 distal to the occlusion 90. In some embodiments, the re-entry device or penetration member 120 may be a guidewire 100 or another guidewire introduced through the guidewire lumen 24 of the catheter shaft 12. In some examples, the re-entry device may have a pre-formed bent distal end portion, where the distal end portion is bent at an oblique angle to the proximal portion of the re-entry device. The bent distal end portion can facilitate exit from the first lateral opening 50 or the second lateral opening 52 when the distal tip of the re-entry device or penetration member 120 encounters a lateral opening. In other examples, the re-entry catheter 10 may include a deflection mechanism that deflects the re-entry device or penetration member 120 through the first lateral opening 50 or the second lateral opening 52. In some examples, the re-entry device or penetration member 120 may include a reduced-diameter penetration tip 125 (shown in Figure 10) that facilitates penetration of the intima layer 82. In other embodiments, the re-entry device or penetrating member 120 may be an elongated member such as a needle cannula or stylet, having a sharp distal tip configured to puncture the distal lumen 88 of the occlusion 90 through the inner lining layer 82.

[0072] In some cases, fluoroscopy may be used to confirm the trajectory of the re-entry or penetration member 120 from the catheter shaft 12 and to ensure that the re-entry or penetration member 120 is advanced toward the true lumen 88 rather than radially outward through the outer membrane layer 86. In addition, or alternatively, an IVUS imaging device 200 may be used to acquire an ultrasound image of the true lumen 88 and to confirm the trajectory of the re-entry or penetration member 120 to ensure that the re-entry or penetration member 120 is advanced toward the true lumen 88. By positioning the imaging lumen 32 laterally to the guidewire lumen 24 such that the IVUS imaging device 200 is positioned laterally adjacent to the re-entry or penetration member 120, the presence of the re-entry or penetration member 120 does not interfere with or obstruct the imaging capabilities of the IVUS transducer 210, and the IVUS transducer 210 can acquire a clear image toward the true lumen 88 at an angle of approximately 90 to approximately 150 degrees.

[0073] If the re-entry device or penetrating member 120 is a guidewire, the catheter 10 may be withdrawn leaving the guidewire routed around the occlusion 90 via a subintima-pathway. In examples where the re-entry device or penetrating member 120 is a separate elongated member such as a needle cannula or stylet, the re-entry device or penetrating member 120 may be removed and replaced with a guidewire. The catheter 10 and / or penetrating member 120 may be withdrawn leaving the guidewire routed around the occlusion 90 via a subintima-pathway.

[0074] In some cases, a capture balloon catheter may be used to maintain the position of a re-entry device / penetration member 120 (or a subsequently positioned guidewire) through the subintima-pathway around the occlusion 90 while the re-ventilation catheter 10 is withdrawn. For example, the re-ventilation catheter 10 may advance through a guide catheter, such as a 6F (2 mm), 7F (2.33 mm), or 8F (2.67 mm) guide catheter, and reach the subintima-space along the occlusion 90, as shown in Figure 8. Before withdrawing the re-ventilation catheter 10 from the vessel after successful re-entry into the true lumen distal to the occlusion 90, a capture balloon catheter can be advanced through the guide catheter along the outside of the re-ventilation catheter 10, and then the capture balloon of the capture balloon catheter can be inflated distal to the re-ventilation catheter 10 within the guide catheter to secure the re-entry device / penetration member 120 or other guidewire to the inner wall of the guide catheter. With the re-entry device / penetration member 120 or other guidewire firmly fixed to the inner wall of the guide catheter to prevent its longitudinal movement, the re-ventilation catheter 10 can be withdrawn from the guide catheter and the blood vessel 80. Once the re-ventilation 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.

[0075] Once a pathway is formed across the occlusion 90 (for example, around the occlusion 90 via a subintima-track), one or more additional medical devices can be advanced through the blood vessel 80 on the re-entry device / penetration member 120 or other guidewire to widen the pathway and / or pass distal to the occlusion 90 to perform further medical procedures.

[0076] Figure 11 is a plan view of an exemplary catheter 110 for recanalizing a blood vessel. The catheter 110 may include an elongated catheter shaft 112 extending distally from a hub assembly 114 to the distal end 122 of the catheter shaft 112. As shown in the cross-sectional view of Figure 12, the catheter shaft 112 may include a guidewire lumen 24 and an imaging lumen 32 extending therein. The distal end region of the catheter shaft 112 may include a lateral opening 150 communicating with the guidewire lumen 24. In some examples, the guidewire lumen 24 may extend from a proximal guidewire port 130 to the distal end 122 of the catheter shaft 12, or the guidewire lumen 24 may terminate at the lateral opening 150. The imaging lumen 32 may extend distally from a proximal port 36 through the catheter shaft 12 beyond the lateral opening 150. In some cases, the imaging tube lumen 32 may extend to the distal tip 122, or it may terminate proximal to the distal tip 122.

[0077] As shown in Figure 12, the catheter shaft 112 may have a circular cross-section with an outer diameter D1 of approximately 0.059 inches (0.150 cm). In some examples, the outer diameter D1 may be, for example, less than or equal to approximately 0.06 inches (0.152 cm), less than or equal to approximately 0.055 inches (0.140 cm), or less than or equal to approximately 0.052 inches (0.132 cm). In some examples, the outer diameter D1 may be, for example, approximately 0.059 inches (0.150 cm), less than or equal to approximately 0.055 inches (0.140 cm), less than or equal to approximately 0.052 inches (0.132 cm), or less than or equal to approximately 0.050 inches (0.127 cm). The outer diameter D1 is similar to that of the Trapper® Exchange, a product commercially available from Boston Scientific, Corp., which has an outer diameter of approximately 0.026 inches (0.066 cm) for the catheter shaft 112 of the catheter 110. The size may be determined so that it can be positioned in parallel with a capture balloon catheter such as a Device, within a 6F (2 mm) guide catheter having an inner lumen diameter of approximately 0.07 inches, such as in the range of approximately 0.070 inches (0.178 cm) to approximately 0.072 inches (0.183 cm); within a 7F (2.33 mm) guide catheter having an inner lumen diameter of approximately 0.08 inches, such as in the range of approximately 0.78 inches (0.198 cm) to approximately 0.082 inches (0.208 cm); or within an 8F (2.67 mm) guide catheter having an inner lumen diameter of approximately 0.09 inches (0.229 cm), such as in the range of approximately 0.088 inches (0.224 cm) to approximately 0.091 inches (0.231 cm).

[0078] The guidewire lumen 24 may have a diameter D2 of approximately 0.017 inches (0.043 cm) to accommodate a 0.014 inch (0.036 cm) guidewire. The imaging lumen 32 may be sized to accommodate an IVUS device, such as the OptiCross® Imaging Catheter commercially available from Boston Scientific, Corp., or its IVUS imaging core, while also providing space for fluid aspiration passing through it alongside the IVUS imaging device. For example, in some examples, the IVUS imaging device may have an outer diameter of approximately 0.025 inches (0.064 cm) or less.

[0079] As shown in Figure 12, the imaging tube lumen 32 may have a non-circular cross-section, shown as an elliptical cross-section with a secondary radius R1 of approximately 0.0165 inches (0.0419 cm) and a principal radius R2 of approximately 0.0212 inches (0.0538 cm), and thus the imaging tube lumen 32 has a distance of approximately 0.0330 inches (0.0838 cm) along its minor axis, a distance of approximately 0.0424 inches (0.1077 cm) along its major axis, and a diameter of approximately 0.00110 square inches (0.00710 cm). 2 ) provides an area of ​​approximately 0.1189 inches (0.3020 cm) and a perimeter of approximately 0.1189 inches (0.3020 cm). In other examples, such as when the outer diameter D1 is approximately 0.052 inches (0.132 cm), the imaging tube lumen 32 may have an elliptical cross-section with a minor radius R1 of approximately 0.0130 inches (0.0330 cm) and a major radius R2 of approximately 0.0175 inches (0.0445 cm), and thus a distance of approximately 0.026 inches (0.066 cm) along its minor axis, a distance of approximately 0.035 inches (0.089 cm) along its major axis, and a perimeter of approximately 0.0007147 square inches (0.0046110 cm). 2The imaging lumen 32 is provided having an area of ​​) and a circumference of approximately 0.09634 inches (0.24470 cm). The lumen may be sized such that the thickness T of the catheter wall is at least 0.003 inches (0.008 cm) at all locations on the catheter shaft 12. In other examples, the lumen may be sized such that the thickness T of the catheter wall is at least 0.002 inches (0.005 cm), at least 0.0024 inches (0.0061 cm), at least 0.0026 inches (0.0066 cm), or at least 0.0028 inches (0.0071 cm) at all locations on the catheter shaft 112.

[0080] As shown in Figure 12, the imaging lumen 32 may have a larger cross-sectional area than the guidewire lumen 24. However, other configurations are also conceivable. As shown in Figure 12, the catheter shaft 112 may be constructed with a guidewire lumen 24 that is parallel to the central longitudinal axis X of the catheter shaft 112 and is perfectly positioned on one side of the plane Y passing through the central longitudinal axis X. The imaging lumen 32 can be positioned such that the central longitudinal axis X of the catheter shaft 112 is within the imaging lumen 32, and the majority of the cross-sectional area of ​​the imaging lumen 32 is positioned parallel to the central longitudinal axis X and on the opposite side of the plane Y passing through the central longitudinal axis X.

[0081] Furthermore, as shown in Figure 12, the catheter shaft 112 may be constructed such that a plane Z extending parallel to the central longitudinal axis X passes through it, and the plane Z passing through it passes through the centers of the guidewire lumen 24 and the imaging lumen 32, respectively. In some examples, plane Z may be perpendicular to plane Y.

[0082] The catheter shaft 112 may include a reinforcing structure 162, such as a braid or coil, to facilitate torque transmission of the catheter shaft, thereby allowing the lateral opening to rotate and orient toward the true lumen of the blood vessel distal to the occlusion. For example, the catheter shaft 112 may include an extruded tubular member 160 that defines the guidewire lumen 24 and the imaging lumen 32. The reinforcing structure 162, such as a braid or coil, may be positioned around (i.e., surrounding) the extruded tubular member 160, and the outer layer 164 may surround the reinforcing structure 162. Therefore, the catheter 110 does not need to include a balloon for rotational orientation.

[0083] The catheter 110 can be advanced into the subintima space in a similar manner to that described above with respect to the catheter 10. The imaging lumen 32 is configured to receive the IVUS imaging device (as described above). The IVUS imaging device is configured to provide ultrasound images of the vessel to confirm the rotational orientation of the lateral opening 150 in the subintima space and / or the trajectory of the re-entry device as it is advanced from the lateral opening 150 toward the true lumen. For example, once the orientation of the lateral opening 150 is confirmed by the IVUS imaging device, the re-entry device can advance through the guidewire lumen 24, exit the lateral opening 150, and re-enter the true lumen distal to the occlusion.

[0084] Those skilled in the art will recognize that aspects of this disclosure can be expressed in various forms other than the specific embodiments described herein and intended to be expressed herein. Accordingly, modifications in form and detail can be made without departing from the scope and spirit of this disclosure as set forth in the appended claims.

Claims

1. A recanalization catheter for facilitating re-entry into the lumen of a blood vessel from the subintima-space of the wall of a blood vessel having an occlusion, wherein the recanalization catheter is: A catheter shaft extending distally from a hub, defining a guidewire lumen extending through the catheter shaft; A first inflatable balloon member and a second inflatable balloon member are positioned in the distal end region of the catheter shaft, wherein the catheter shaft includes an expansion lumen that is in fluid communication with the first inflatable balloon member and the second inflatable balloon member; A lateral opening communicating with the guidewire lumen, the lateral opening opening to the outside of the catheter shaft between the first inflatable balloon member and the second inflatable balloon member on the first side of the catheter shaft; An imaging lumen extending through the catheter shaft and configured to receive an IVUS imaging device; A re-communication catheter equipped with [a specific feature / equipment].

2. The re-drainage catheter according to claim 1, wherein the expansion lumen includes a first expansion lumen that is in fluid communication with the first inflatable balloon member and a second expansion lumen that is in fluid communication with the second inflatable balloon member.

3. The re-drivability catheter according to claim 2, wherein in the proximal portion of the catheter shaft, the central longitudinal axis of the catheter shaft passes through the imaging lumen, and the entirety of the first expansion lumen, the second expansion lumen, and the guidewire lumen are positioned on the first side of a first virtual plane that extends parallel to the central longitudinal axis and passes through the central longitudinal axis.

4. The re-draining catheter according to claim 3, wherein in the distal portion of the catheter shaft, the imaging lumen and the guidewire lumen are positioned between the first expansion lumen and the second expansion lumen, so that a second virtual plane extending parallel to the central longitudinal axis and passing through the central longitudinal axis passes through the first expansion lumen, the second expansion lumen, the imaging lumen, and the guidewire lumen, respectively.

5. The re-draining catheter according to any one of claims 1 to 4, wherein the proximal portion of the catheter shaft has a circular cross-sectional shape, and the distal portion of the catheter shaft has a substantially rectangular cross-sectional shape.

6. The re-drivability catheter according to any one of claims 1 to 5, wherein the first and second inflatable balloon members are configured to inflate laterally from both sides of the catheter shaft along a third virtual plane, the third virtual plane passing through the imaging lumen and the guidewire lumen, respectively.

7. The re-drainage catheter according to any one of claims 1 to 6, further comprising an IVUS imaging device that can be positioned within the imaging tube lumen to position an IVUS transducer distal to the first lateral opening.

8. The re-canalization catheter according to any one of claims 1 to 7, wherein the outer diameter of the catheter shaft is 0.059 inches (0.150 cm) or less, the guidewire lumen has a diameter of approximately 0.017 inches (0.043 cm), and the minimum distance across the imaging lumen through the central axis of the imaging lumen is 0.033 inches (0.084 cm) or more.

9. The re-canalization catheter according to any one of claims 1 to 7, wherein the outer diameter of the catheter shaft is 0.052 inches (0.132 cm) or less, the guidewire lumen has a diameter of approximately 0.017 inches (0.043 cm), and the minimum distance across the imaging lumen through the central axis of the imaging lumen is 0.026 inches (0.066 cm) or more.

10. The re-draining catheter according to claim 8 or 9, wherein the wall thickness of the catheter shaft at all positions along the catheter shaft is at least 0.003 inches (0.008 cm).

11. A recanalization catheter for facilitating re-entry into the lumen of a blood vessel from the subintima-space of the wall of a blood vessel having an occlusion, wherein the recanalization catheter is: A catheter shaft extending distally from the hub; An expandable balloon positioned in the distal end region of the catheter shaft; Equipped with, The catheter shaft is A guide wire lumen extends through it; The expansion tube lumen is in fluid communication with the inside of the expandable balloon; An imaging lumen extending through the catheter shaft and configured to receive an IVUS imaging device; A re-canalization catheter is an extruded tubular member that defines a re-canalization point.

12. The re-drainage catheter according to claim 11, further comprising an IVUS imaging device disposed within the imaging lumen, wherein the IVUS transducer of the IVUS imaging device is positioned distal to the expandable balloon.

13. A recanalization catheter for facilitating re-entry into the lumen of a blood vessel from the subintima-space of the wall of a blood vessel having an occlusion, wherein the recanalization catheter is: A catheter shaft extending distally from the hub; An inflatable balloon positioned on the distal end region of the catheter shaft, comprising a first inflatable balloon member on a first side surface of the catheter shaft and a second inflatable balloon member on a second side surface of the catheter shaft opposite to the first side surface; Equipped with, The catheter shaft comprises an extruded proximal tubular member having a circular cross-sectional shape and an extruded distal tubular member having a substantially rectangular cross-sectional shape, wherein the catheter shaft is: The extruded proximal tubular member and the guidewire lumen extending through the extruded distal tubular member; A first expansion lumen extending through the extruded proximal tubular member and the extruded distal tubular member, the first expansion lumen being in fluid communication with the interior of the first inflatable balloon member; A second expansion lumen extending through the extruded proximal tubular member and the extruded distal tubular member, the second expansion lumen being in fluid communication with the interior of the second inflatable balloon member; An imaging lumen extending through the extruded proximal tubular member and the extruded distal tubular member, configured to receive an IVUS imaging device therein; A re-canalization catheter that defines the area.

14. The re-draining catheter according to claim 13, further comprising a lateral opening communicating with the guidewire lumen, wherein the lateral opening opens to the outside of the catheter shaft between the first inflatable balloon member and the second inflatable balloon member.

15. The re-drainage catheter according to claim 14, further comprising an IVUS imaging device disposed within the imaging lumen, wherein the IVUS transducer of the IVUS imaging device is positioned distal to the lateral opening, preferably distal to the expandable balloon.

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