EP-4736931-A2 - REENTRY CATHETERS FOR TRAVERSING CHRONIC TOTAL OCCLUSIONS

Abstract

A reentry catheter for crossing a vascular occlusion includes an elongate flexible tubular body, having a proximal end, a distal end and at least one lumen extending there through. A reentry zone on the tubular body includes at least two and preferably three sets of opposing pairs of axially spaced exit apertures in communication with the lumen. The apertures are rotationally offset from each other and aligned in a spiral pattern around the tubular body. A method of crossing a chronic total occlusion includes the steps of advancing the reentry catheter across the occlusion via a channel formed in the subintimal space, and advancing a guidewire via a selected exit port into the native lumen distally of the occlusion. The catheter may be removed, leaving the guidewire across the occlusion to guide further interventional devices.

Inventors

• NICHOLSON, BILL
• KLOS, Brad
• HOWARD, STEVE
• MATSUURA, DAVID

Assignees

• Traverse Vascular, Inc.

Dates

Publication Date

20260506

Application Date

20200402

Claims (15)

1. An intravascular catheter system comprising: a reentry catheter comprising: an elongate tubular body having a proximal end, a distal end, and a lumen extending therethrough, the lumen configured to receive a guidewire; and a reentry zone positioned within about 40 cm of the distal end of the elongate tubular body, the reentry zone comprising opposing pairs of side wall apertures configured to accommodate passage of the guidewire therethrough, each opposing pair of side wall apertures axially spaced apart and rotationally offset from each other; and a vacuum source coupled to the proximal end of the elongate tubular body.
2. The intravascular catheter system of claim 1, wherein an inner diameter of the elongate tubular body within the reentry zone is 150% to 200% greater than an outer diameter of the guidewire.
3. The intravascular catheter system of claim 1, wherein an inner diameter of the elongate tubular body within the reentry zone is at least about 0.010 inches greater than an outer diameter of the guidewire.
4. The intravascular catheter system of claim 1, wherein a distal edge of each of the side wall apertures comprises a ramped surface.
5. The intravascular catheter system of claim 1, wherein the vacuum source comprises an aspirator, and a space between the guidewire and an inner wall of the elongate tubular body defines an aspiration flow path.
6. The intravascular catheter system of claim 1, wherein each of the side wall apertures is oblong.
7. The intravascular catheter system of claim 1, wherein a distal portion of the reentry zone further comprises a plurality of tip anchors.
8. The intravascular catheter system of claim 7, wherein the plurality of tip anchors comprises axially extending ribs.
9. The intravascular catheter system of claim 7, wherein a proximal portion of the reentry zone further comprises a plurality of anchors.
10. The intravascular catheter system of claim 9, wherein the plurality of anchors comprises proximally extending ribs.
11. The intravascular catheter system of claim 10, wherein the proximally extending ribs are shorter than the axially extending ribs.
12. The intravascular catheter system of claim 9, wherein the plurality of anchors overlaps a distal portion of a braid layer of the elongate tubular body.
13. The intravascular catheter system of claim 1, further comprising a plurality of radiopaque rings, each radiopaque ring surrounding one of the side wall apertures.
14. The intravascular catheter system of claim 13, further comprising a frame connecting the radiopaque rings, wherein portions of the frame between the radiopaque rings comprise helical struts.
15. The intravascular catheter system of claim 14, wherein a stiffness of the helical struts decreases along the reentry zone, such that a distal portion of the reentry zone is less stiff than a proximal portion of the reentry zone.

Description

Cross-Reference to Related Applications This application claims priority to U.S. Provisional Patent Application No. 62/830,199, filed April 5, 2019, and U.S. Provisional Patent Application No. 62/907,299, filed September 27, 2019, the entire contents of both of which are incorporated herein by reference in their entireties. BACKGROUND OF THE INVENTION An interventional guide wire or other interventional device is often used in medical procedures that attempt to establish a pathway through a heavily stenosed or chronically occluded vessel. A chronically occluded vessel is referred to as containing a chronic total occlusion or CTO. During these procedures, the guide wire or device can only be of clinical benefit to establish vessel patency if it is advanced distally into the vessel true lumen. One technique for restoring patency across a CTO involves advancing a guide wire through the intimal layer of the vessel wall and into the subintimal plane or space, where it can be further advanced distally beyond the CTO. Once in this sub-intimal plane beyond the CTO, it becomes difficult to navigate the guide wire or device back through the subintimal tissue layer to re-gain access into the vessel true lumen, sometimes referred to as a "reentry" into the vessel lumen from the sub-intimal space distally of the CTO. The layer of tissue that separates the vessel true lumen from the subintimal plane is typically in the range from 100 to 500 micrometers thick for vessels in the diameter range from 2 mm to 4 mm, and from 100 to 3000 microns thick, in the largest vessels of the body. A variety of catheters have been proposed for reentry around a CTO. One is described and shown in U.S. Pat. No. 6,231,546. In this system, the re-entry catheter requires the operator to rotate a catheter shaft while observing a radiopaque marker on the catheter shaft to ensure that a side or lateral port is aimed at the true lumen of the blood vessel. Once the marker indicates the correct orientation of the lateral port, a cannula is extended through the lateral port in order to penetrate through the intimal layer of the blood vessel. It is believed that one drawback of this system is the requirement to rotate the catheter to the correct position while under fluoroscopic imaging otherwise an incorrect orientation of the cannula could cause failure to reenter the parent lumen and potentially cause damage to the vessel. Another system is described and illustrated in US Patent Application Publication 2013/0072957. In this publication, a balloon is used to orient the cannula into the proper orientation for re-entry into the true vessel lumen. To achieve this, the catheter utilizes an asymmetrical catheter lumen for the cannula. It is believed that this system also suffers from a similar drawback in that the lateral port of the cannula must be oriented in the correct direction towards the true lumen while under fluoroscopy. This is to ensure that the cannula does not penetrate away from the true lumen, which could lead to internal hemorrhaging. Despite the foregoing and other efforts in the prior art, there remains a need for an improved reentry catheter and method for traversing total chronic occlusions. SUMMARY OF THE INVENTION Disclosed is a reentry catheter for crossing a vascular occlusion. The catheter includes an elongate flexible tubular body, having a proximal end, a distal end and at least one lumen extending there through. A reentry zone on the tubular body includes at least two and preferably at least three or five or more exit apertures in communication with the lumen, the apertures rotationally offset from each other by at least about 15 degrees and aligned in a spiral pattern around the tubular body. In one implementation, three pairs of opposing apertures are provided. A method of crossing a chronic total occlusion includes the steps of advancing a guidewire from a vascular lumen through the intima, into a subintimal space and distally beyond the occlusion. A reentry catheter is advanced over the guidewire and beyond the occlusion, such that at least one of a plurality of spirally aligned exit ports on the reentry catheter is rotationally aligned with the lumen. The guidewire is advanced through the at least one exit port to cross the intima and reenter the lumen. The reentry catheter may be removed, and a balloon catheter may be advanced over the wire and the balloon expanded in the subintimal space to create a neolumen that permits perfusion across the occlusion. A stent may be expanded in the neolumen to maintain patency across the occlusion. There is provided, in accordance with another aspect of the present invention, a re-entry catheter for crossing a vascular occlusion. The catheter comprises an elongate flexible tubular body, having a proximal end, a distal end and at least one lumen extending there through. A reentry zone is defined on the tubular body, comprising at least two exit apertures in communication with the lumen,