Reentry catheter with expanding anchors

A reentry apparatus has an outer catheter configured to accommodate a first reentry device and an inner catheter configured to fit within the outer catheter. The inner catheter has a series of expanding anchors extending from the outer surface of the inner catheter and a reentry channel configured to accommodate a second reentry device. A retaining wire extends along the upper surface of the expanding anchors. A reentry channel is located in the configured to accommodate a second reentry device.

TECHNICAL FIELD

Exemplary embodiments of the present invention generally relate to a catheter apparatus for performing intravascular procedures, such as but not limited to, reentries.

BACKGROUND AND SUMMARY OF THE INVENTION

Atherosclerosis, or hardening of the arteries, is a medical condition where atherosclerotic material (i.e., plaque) accumulates along the inner walls of a blood vessel. As plaque builds up, the blood vessel may become partially or completely blocked, leading to issues such as coronary heart disease, angina, carotid artery disease, peripheral artery disease, and chronic kidney pain. Sometimes blood clots form near the blockage, or a piece of the blockage breaks off, and travels through the person's vascular system, which can potentially result in a heart attack or a stroke. Various intervention devices and procedures have been developed to treat atherosclerosis and related issues. Many of these intervention devices are now designed for intravascular use so as to minimize the invasiveness of the procedure.

A common example is an angioplasty. During an angioplasty procedure, an intravascular device(s) is used to move a balloon through a persons' vascular system to the site of the blockage. Once appropriately positioned, the balloon is inflated to compress the surrounding plaque, thereby increasing the lumen available for blood flow. The balloon is then deflated and removed and oftentimes a stent is inserted to help keep the plaque in its newly compressed state. However, in some cases the plaque blockage is too large, which prevents the angioplasty balloon or other intervention device from being appropriately positioned to perform the treatment. In such cases the procedure must generally be aborted unless the blockage can be circumnavigated (i.e., crossed).

Chronic Total Occlusions (“CTOs”) are one type of plaque blockage that often requires such crossing. CTOs are generally blockages classified as having a Thrombolysis In Myocardial Infarction (“TIMI”) grade flow of 0 or 1; 0 (no perfusion) referring to the absence of any antegrade flow beyond a coronary inclusion, and 1 (penetration without perfusion) referring to a faint antegrade coronary flow beyond the occlusion, with incomplete filing of the distal coronary bed. Regardless, when a CTO or other serious plaque blockage is encountered, a reentry catheter may be used to cross the blockage.

Typically, the reentry catheter is advanced along a guidewire either through the blockage itself or into the layered walls of the blood vessel where it can then be advanced passed the blockage. Once the reentry catheter is sufficiently advanced through or past the blockage, a tool is used to reenter the true lumen of the blood vessel. Using the tool, the guidewire is advanced past the blockage and into the true lumen of the blood vessel. The reentry catheter is then typically removed and the desired intervention device may be advanced into position and used to treat the person. An example of such a device is the Outback® LTD® reentry catheter by Cordis® (https://emea.cordis.com/emea/endovascular/lower-extremity-solutions/cross/outback-ltd-re-entry-catheter.html).

Known devices, however, can be difficult and cumbersome to operate. They may require precise positioning and movement to perform the reentry procedure and may not be particularly stable. Further, known devices may provide only one reentry port configured to accommodate a single reentry device at a single angle. This can be particularly problematic as unpredictable wall thicknesses, blockage positioning, material compositions, and calcification densities can require differently positioned, sized, and types of reentry devices to perform a successful cross. Therefore, what is needed is a reentry catheter that is easy to use and provides multiple reentry ports for multiple reentry devices.

The present invention is a reentry catheter that is easy to use and provides multiple reentry ports for multiple reentry devices. The reentry catheter may comprise an outer catheter tube surrounding an inner catheter, both extending from a handle assembly. The inner catheter may be configured to normally remain substantially in line with the outer catheter, but upon removal from the outer catheter, revert to a pre-shaped state wherein the distal portion of the inner catheter is bent at an angle.

A series of expanding anchors may be located long the outer wall of the inner catheter and when the inner catheter is located inside of the outer catheter, the expanding anchors may be placed in a compressed state. However, once positioned at a treatment site, the inner catheter may be advanced relative to the outer catheter, thus exposing some or all of the expanding anchors. The expanding anchors may expand against the blood vessel wall, stabilizing the device and forcing the distal portion of the inner catheter towards a reentry target. Once appropriately positioned, a user of the device may advance a first or a second reentry device through one of two reentry apertures the inner catheter. Preferably, a first reentry aperture is located on the distal end of the inner catheter and a second reentry aperture is located along the side wall of the inner catheter such that the first and the second reentry device exit the inner catheter at different angles.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT(S)

FIG. 1is a plan view of an exemplary reentry catheter10in accordance with the present invention, also indicating detail A. The reentry catheter10may comprise a handle assembly12connected to an outer catheter24. The outer catheter24may be tubular in shape and may be sufficiently flexible to navigate the sinuous passages of the human vascular system. In exemplary embodiments of the present invention, the handle assembly12may be connected to the outer catheter24by way of an attachment member21. The attachment member21may be configured to permit the outer catheter24to move rotationally relative to the handle assembly12. Otherwise, the handle assembly12may be integrally formed with, adhered to, bonded with, or otherwise attached to the outer catheter24.

The outer catheter24may extend from the handle assembly12to a distal end portion20. An inner catheter26may be positioned within the outer catheter24and may be substantially concentric therewith. The inner catheter26may also be tubular in shape and may be sufficiently flexible to navigate the sinuous passages of the human vascular system. A guidewire14may likewise be positioned within the inner catheter26and may be substantially concentric therewith. The guidewire14may likewise be tubular in shape and may be sufficiently flexible to navigate the sinuous passages of the human vascular system. The guidewire14may additionally pass through the handle assembly12.

The handle assembly12may comprise various mechanisms for controlling the distal end portion20of the reentry catheter10and one or more reentry devices, such as a first reentry device40and a second reentry device42, for the purposes described in greater detail herein. The first and second reentry devices40and42may be a needle, wire, transluminal catheter, or the like. Furthermore, the reentry devices40and42may be angled, straight, or otherwise pre-shaped. In this fashion, the first and second reentry devices40and42may be configured to reach separate reentry targets. The attachment member21may be used to orient the inner catheter26such that the first and second reentry devices40and42are aligned with the reentry target(s).

In exemplary embodiments of the present invention, the handle assembly12may comprise a groove16having a number of protrusions18located along the groove16at regular intervals. A control member23may be located within, and protrude from, the groove16and be configured to selectively frictionally engage the protrusions18so as to temporarily secure the control member23at a given location. The control member23may be in communication with the inner catheter26and may be configured to control movement of the inner catheter26relative to the outer catheter24as will be described in greater detail herein.

Similarly, the handle assembly12may further comprises a second groove13and a third groove15, each having a series of protrusions18for selective frictional engagement with a second control member17and a third control member19located in each, respectively. The second control member17may be located within, and protrude from, the second groove13and may be in communication with the first reentry device40. The third control member19may similarly be located within, and protrude from, the third groove15and may be in communication with the second reentry device42. The second and third control members17and19may be configured to control movement of the first and second reentry device40and42, respectively, as will be described in greater detail herein.

The advancement of the reentry device40and42may be limited by the second or third control members17and19, respectively, or by the length or range of the first or the second reentry devices40and42themselves. In exemplary embodiments of the present invention, the first or the second reentry devices40and42have a range of 4 mm, 5 mm, 10 mm, and 15 mm, reached by moving the second and third control members17and19each respective protrusion18in the second and third grooves13and15. However, any length or range of the first and second reentry devices40and42at any number or length intervals is contemplated. Furthermore, protrusions in the second and third grooves13and15may not be required such that the user can fluidly operate the second and third control members17and19any range.

It is notable that the control member23, second control member17, and third control member19may be any of type, style, size, or shape such as, but not limited to, a knob, dial, button, slider, lever, member, or the like. They may interact directly with the inner catheter26, first reentry device40, and second reentry device42, respectively, or may do so through an intermediary such as, but not limited to, linkages, members, gears, levers, cams, shafts, motors, wiring, electrical controls, and the like.

The inner catheter26, outer catheter24, and other components of the reentry catheter10may be comprised of a metallic, polymer, or other suitable biocompatible material. The inner catheter26, outer catheter24, and other components of the reentry catheter10may be comprised of the same or different materials.

FIG. 2is a detailed side view of detail A ofFIG. 1, illustrating the distal end portion20of the reentry catheter10. The inner catheter26is shown retracted relative to the outer catheter24, though the inner catheter26may be further retracted such that it resides entirely within the outer catheter24. The outer catheter24and the inner catheter26may comprise one or more radiopaque markers22A and22B. In exemplary embodiments of the present invention, the outer catheter24may have a single radiopaque marker22A located near an end thereof and the inner catheter26may have a number of radiopaque markers22B located beginning near the distal portion thereof and continuing along a length thereof. In exemplary embodiments of the present invention, the radiopaque markers22A located on the outer catheter24are sufficiently distinguishable from the radiopaque markers22B located on the inner catheter26such that a user of the reentry catheter10may determine how far the inner catheter26is extended relative to the outer catheter24as well as the angle and vertical position of the distal tip of the inner catheter26relative to the distal tip of the outer catheter24. To accomplish this, for example but not to serve as a limitation, the radiopaque markers22A located on the outer catheter24may be of a different shape than the radiopaque markers22B located on the inner catheter26. However, any number, size, or shape of radiopaque markers22A an22B at any number of locations is contemplated.

The distal portion of the inner catheter26may comprise a first reentry aperture28and a second reentry aperture30. The first reentry aperture28may be located on the distal portion of the inner catheter26. The second reentry aperture30may be located along the side wall of the inner catheter26, a short distance from the distal tip thereof. In exemplary embodiments of the present invention, the second reentry aperture30is located approximately 2 mm from the distal tip of the inner catheter26, though any location is contemplated. Also in exemplary embodiments of the present invention, the first and second reentry apertures28and30are configured to be set at different angles such that the corresponding reentry devices40and42exit the corresponding reentry apertures28and30at different angles. In this fashion, the first and second reentry device40and42may be configured to reach separate reentry targets.

FIG. 3is a front sectional view taken along section line A-A ofFIG. 2. The inner catheter26may be located substantially concentric with the outer catheter24. The inner lumen27formed by the inner catheter26may also serve as the first reentry aperture28. A reentry channel32may be located within the inner lumen27and is preferably oval shaped and positioned along the bottom of the inner lumen27, though any shape and location is contemplated. The reentry channel32may provide stiffening and support to the inner and outer catheters26and24. The reentry channel32may extend the length of the inner catheter26and the outer catheter24and may be sized and configured to accommodate the first reentry device40and the second reentry device42such that they do not inadvertently contact the inner or outer catheters26and24. The guidewire14may be positioned to pass through the reentry channel32. However, along some or all of the reentry catheter10, the guide wire14may instead be positioned substantially concentric to the inner catheter26.

FIG. 4is a detailed side view of the device ofFIG. 2illustrated with the inner catheter26extended relative to the outer catheter24. The inner catheter26may be pre-shaped by use of a memory material, weakened regions, resiliently deformable material, or the like, though such is not required. In exemplary embodiments of the present invention, the inner catheter26is pre-shaped such that the distal portion thereof deflects downward at substantially a 45-degree angle after being extended from the outer catheter24, though any direction or angle of deflection is contemplated.

As the inner catheter26is extended relative to the outer catheter24, one or more expanding anchors34may be exposed. The expanding anchors34may be crescent shaped and may be attached to the outer surface of the inner catheter26. In exemplary embodiments of the present invention, the expanding anchors34may be biased in an expanded state such that the expanding anchors34automatically expand once removed from the outer catheter24. The expanding anchors34may be comprised of a resiliently deformable material such as, but not limited to, nitinol. The expanding anchors34may be set at regular intervals along the outer surface of the inner catheter26, though any number of expanding anchors34in any number of locations is contemplated.

A retaining wire36may run along the top of one or more of the expanding anchors34and be attached at the distal tip of the inner catheter26on one end and at a location on the inner catheter beyond the final expanding anchor34on a second end, though the retaining wire36may also be attached to one or more of the expanding anchors34. The retaining wire26may serve to limit the expansion of the expanding anchors34thereby functioning as a safety device by preventing the expanding anchors34from expanding beyond their intended design. The retaining wire36may also function to keep the expanding anchors34evenly spaced apart.

In other exemplary embodiments of the present invention, movement of the inner catheter26relative to the outer catheter24, and thus deployment or retraction of the expanding anchors34, may be accomplished by pulling or pushing on the retaining wire36, which may also act as a control line. In such embodiments, the retaining wire/control line36may run the length of the outer catheter24and may be in communication with the control member23.

As previously explained, movement of the inner catheter26relative to the outer catheter24may be controlled by corresponding movement of the control member23located on the handle assembly12such that movement of the control member23is translated to movement of the inner catheter26. Additionally, rotation of the inner catheter26relative to the outer catheter24may be accomplished by movement of the attachment member21or by another control mechanism. In exemplary embodiments of the present invention, movement of the control member23to each subsequent protrusion18on the groove16may result in sufficient movement of the inner catheter26so as to expose two additional expanding anchors34.

The expanding anchors34may be configured to expand different amounts, which may be dictated by the length, attachment points, material characteristics, the like, or some combination thereof, of the expanding anchors34. As the expanding anchors34may be constrained by the retaining wire36, when all of the expanding anchors34are exposed, they may form a substantially curved profile. In exemplary embodiments of the present invention, the expanding anchors34may expand up to 8 mm, though it is contemplated that any number of the expanding anchors34may be expanded any amount.

When one or more of the expanding anchors34are exposed, and thus placed in the expanded state, the expanding anchors34may begin to push against the outer wall of a blood vessel46or other surrounding tissue, stabilizing the distal end portion20as well as forcing the distal tip of the inner catheter26to deflect downward towards the reentry target. As more expanding anchors34are exposed, the force on the distal portion of the inner catheter26may be increased, resulting in greater deflection of the distal tip of the inner catheter26. In exemplary embodiments of the present invention, the exposure of each additional expanding anchor34corresponds to a 1 mm vertical drop of the distal tip of the inner catheter26, though any distance is contemplated. The distal portion of the inner catheter26may be configured to deflect or drop a specified amount by the location and configuration of the expanding anchors34, by pre-shaping the inner catheter26, through the strategically located use of weakened regions, some combination thereof, or the like.

In other exemplary embodiments of the present invention, the expanding anchors34may be configured to expand an increasing amount as more of the inner catheter26is exposed, which may be configured to correlate with either an increased or a consistent vertical drop with the exposure of each additional expanding anchor34. The amount of expansion and resulting force implemented by the expanding anchors34may be adjusted to any amount. In exemplary embodiments of the present invention, the amount of expansion and resulting force and vertical travel is adjusted to account for the anticipated resistance of the tissue to be reentered or the reentry targets to be accessed.

The guidewire14, outer catheter24, and inner catheter26may be of any length, size, and shape. In fact, the size, length, and/or shape of the guidewire14, outer catheter24, and inner catheter26may be adjusted to perform various procedures with the reentry catheter10. However, in exemplary embodiments of the present invention, the first reentry aperture28and the inner lumen27may have an internal diameter of 0.35 inches and the inner catheter26may have an outer diameter of 0.46 inches (including the expanding anchors34when in the compressed state). The outer catheter24may have an outer diameter of 0.5 inches and an inner diameter of 0.48 inches. The reentry channel32and the second reentry aperture30may have an inner diameter of 0.16 inches or be sized and configured to accommodate a 0.14-0.18 inch diameter reentry device, wire, needle, transluminal catheter, or other tool. These measurements are merely exemplary and are not intended to be limiting. Any size or shape for the reentry catheter10and its various components is contemplated.

FIG. 5is a detailed side view similar toFIG. 4, illustrating another exemplary embodiment of the reentry catheter10wherein one or more of the expanding anchors34further comprises a webbing38located within the arch formed by the expanding anchors34. The webbing38may be comprised of a metallic, such as but not limited to, a nitinol mesh. The webbing38may be configured to provide additional structural support and stability and may additionally assist in controlling the expansion of the expanding anchors34.

FIG. 6andFIG. 7illustrate another exemplary embodiment of a distal end portion120of the reentry catheter10where similar features are numbered similarly (i.e.,26and126). In this exemplary embodiment of the present invention, a section144of the distal end portion120may be formed at an angle. For example, but not to serve as a limitation, the angled section144of the distal end portion120may be integrally formed bend at a first location such that it is pre-shaped. The expanding anchors134may be located after the pre-shaped section144. Any type or amount of pre-shaping is contemplated, including any direction, amount, or angle of bend.

As the inner catheter126is advanced relative to the outer catheter124, and the expanding anchors134are thus removed from the inner catheter126, the expanding anchors134may expand against the blood vessel46or other surrounding tissue, thereby forcing the inner catheter126to deflect downward over a second section143thereof which is located proximally relative to the first, pre-shaped section144. The angle and direction of the bend along the second section143may be the same or different from the direction or angle of the pre-shaped section144. Though the present embodiment is shown with a single pre-shaped section144, any number of pre-shaped sections at any number of locations is contemplated.

FIG. 8is a plan view for an exemplary system utilizing the present invention. A person52may be placed on a table for performing the procedure. An imaging device50may be positioned to periodically or continuously capture images of the reentry catheter10or the person's52vascular system. Such imaging devices50are known in the art and typically use fluoroscopy techniques so that the user of the reentry catheter10can monitor the location and movement of the reentry catheter10, particularly by using the radiopaque markers22A and22B located thereon while performing the procedures shown and described herein.

As will be shown and described in greater detail herein, the guidewire14may initially be inserted intravascularly into the person52. The guidewire14may be advanced through the person's52vascular system until it reaches a treatment site or until its pathway is impeded by a blockage48. In exemplary embodiments of the present invention, multiple devices may be used along the same guidewire14. In such cases, it may sometimes be necessary to remove the device currently being used on the guidewire14before inserting the reentry catheter10. Regardless, the reentry catheter10may then be advanced along and beyond the guidewire14into or through at least a portion of the blockage48. In other exemplary embodiments of the present invention, the reentry catheter10may instead be advanced along and beyond the guidewire14and into or through the surrounding layers45that form the wall of the blood vessel46, or through other surrounding tissue, such that the reentry catheter10may circumnavigate the blockage48. The inner catheter tube26may be rotated such that the first and second reentry apertures28and30, and thus the projected path of the first and second reentry device40and42, are aligned with the reentry target(s). Once positioned appropriately, the inner catheter tube26may be advanced relative to the outer catheter tube24by movement of the control member23on the handle assembly12such that appropriate number of expanding anchors34are exposed to deflect the distal end of the inner catheter26the appropriate amount, thereby positioning the first or second reentry apertures28and30to align the intended path of the first or second reentry devices40and42with the intended reentry target(s).

Next, the first or the second reentry devices40and42may be advanced through the first or second reentry apertures28and30, respectively, using the second or third control members17and19, respectively. The advancement of the reentry device40and42may be limited by the second or third control members17and19, respectively, or by the length of the first or the second reentry devices40and42themselves. In exemplary embodiments of the present invention, the first or the second reentry devices40and42are 4 mm in length, though any length is contemplated. The reentry devices40and42may pierce the blockage48, the wall of the blood vessel46, or the surrounding tissue such that the reentry device40or42reenters the true lumen of the blood vessel46or otherwise accesses the reentry target(s). Regardless, once the reentry device40or42is advanced beyond the blockage48(i.e., crossed), or the reentry target is accessed, the guide wire14may be advanced through the appropriate reentry device40or42. Should one of the reentry apertures28or30not be properly positioned or one of the reentry device40or42be unable to perform the reentry, the other reentry aperture28or30and reentry device40or42may be utilized. This may be particularly advantageous as tissue resistance may vary by location. Alternatively, the first and second reentry apertures28and30and first and second reentry devices40and42may be utilized to reach two separate reentry targets.

Regardless, the reentry catheter10may then be removed and the appropriate intervention may be performed. However, in other exemplary embodiments of the present invention, the intervention is performed using the reentry catheter10by advancing appropriate tools therethrough. Such interventions may include, but are not limited to, trans-luminal, trans vascular to organs and trans-vascular transfers of vascular devices, drugs, target organ biopsy and selective angiography. The present invention is not limited to crossing CTOs, but may be used to cross any type of blockage or access any reentry target(s) as well as perform reentries related to any applicable procedures.

FIG. 9is a detailed side view of the device ofFIG. 4, illustrating the distal end of the reentry catheter20crossing a blockage48in a blood vessel46using an exemplary technique. In this exemplary embodiment, the reentry catheter10is advanced through at least a portion of the blockage48. When the reentry catheter10is appropriately positioned or cannot be advanced further, the inner catheter26may be advanced relative to the outer catheter24, thus deflecting the distal end of the inner catheter26, and the reentry devices40or42may then be extended from the first or second reentry apertures28or30respectively until they reach beyond the blockage48into the true lumen of the blood vessel46or reach the reentry target(s). The guide wire14or other tool may then be advanced through the first or the second reentry device40or42and into the true lumen of the blood vessel46, thus crossing the blockage48. In another exemplary application, but not to serve as a limitation, the reentry catheter10may be used to pass through the wall of the blood vessel46and access neighboring organs to perform a biopsy. Regardless, the reentry catheter10may then be removed. If required, an intervention or other treatments may then be performed.

FIG. 10is a detailed side view similar toFIG. 9, illustrating how the reentry catheter10may alternatively be used to circumnavigate the blockage48using another exemplary technique. The distal end portion20of the reentry catheter10may be manipulated into the layers45that form the wall of the blood vessel46. The distal end portion20may be advanced near or beyond the end of the blockage48. The inner catheter26may be advanced relative to the outer catheter24, thus deflecting the distal end of the inner catheter26, and the reentry device40or42may then be extended from the first or the second reentry apertures28or30, respectively, such that the first or the second reentry devices40and42may be extend into true lumen of the blood vessel46. The guide wire14or other tool may then be advanced through the first or the second reentry device40or42and into the true lumen of the blood vessel46, thus crossing the blockage48. The expanding anchors34may be forced back into a collapsed state as the inner catheter26is retracted relative to the outer catheter24. Once the inner catheter26is completely retracted, the reentry catheter10may be removed and the intervention or other treatment may proceed.

FIG. 11is a detailed side view of another exemplary embodiment of the distal end220of the reentry catheter10using another exemplary technique for crossing a blockage48in a blood vessel46where similar features are numbered similarly (i.e.,26and226). The distal end220may be used to cross blockages48such as, but not limited to, CTOs. The reentry devices40and42may be wires, boring tools, cutting devices, abrasive surfaces, or other tools configured to create a passage through the blockage48. In such embodiments, the reentry devices40and42may be manipulated by rotation or other movement of the inner catheter226relative to the outer catheter224. This may be accomplished, for example, by use of the attachment member21which may be in communication with the inner catheter226such that rotation of the attachment member21causes rotation of the inner catheter226. For example, but not to serve as a limitation, one or more of the reentry device40and42may comprise a tapered tip having an abrasive outer surface. In this way, the reentry device40and42may be advanced relative to the distal end portion220while being rotated so as to bore through the blockage48.

FIG. 12Ais a detailed side view of another exemplary embodiment of the distal end320of the reentry catheter10using another exemplary technique for crossing a blockage48in a blood vessel46where similar features are numbered similarly (i.e.,26and326). In this embodiment, the first reentry device340may have a large diameter and may be configured to bore through the blockage48. This figure is intended to illustrate that any size reentry devices340or342may be utilized with the present invention. The first or the second reentry apertures328and330may be appropriately sized to fit said reentry devices340and342.

FIG. 12Bis a detailed side view of the device ofFIG. 12Afollowing a successful crossing of the blockage48in the blood vessel46.