BACKGROUND

Chronic Total Occlusion (“CTO”) is a complete or near complete blockage of a blood vessel, such as a coronary artery. As many as 30% of the patients with coronary artery disease have CTOs somewhere through the left or right arterial system. Traditionally CTO has usually been treated by a bypass procedure where an autologous or synthetic blood vessel is anastomotically attached to locations on the blood vessel upstream and downstream of the occlusion. While effective, such bypass procedures are quite traumatic to the patient.

Recently, catheter-based intravascular procedures have been developed to treat CTO with improved success rates. Such procedures include angioplasty, atherectomy, stenting, and the like, and the catheters are usually introduced percutaneously. Treatment of CTO percutaneously significantly reduces the need for surgery (coronary artery bypass graft—CABG). Moreover, CTO percutaneous coronary intervention (PCI) can result in symptomatic relief for the patient, re-establishing coronary blood flow, improved left ventricular function and potentially, survival advantage. Peripheral vascular occlusions outside of the coronary vascular anatomy are also treatable with such interventions.

Before such catheter-based treatments can be performed, it is usually necessary to cross the occlusion with a guidewire to provide access for the interventional catheter. Available techniques for crossing the occlusion generally fall into two approaches: the antegrade approach, which involves crossing a wire from the proximal end to the distal end of the occlusion (either through the CTO directly or through the subintimal space), and the retrograde approach, which refers to CTO access of the distal cap via collateral vessels. The latter is usually reserved as a second line strategy for failed intimal antegrade crossing.

For treating CTO by PCI with antegrade access, a number of different devices have been developed, including the CrossBoss™ and Stingray™ systems. See http://www.bostonscientific.com/en-US/medical-specialties/interventional-cardiology/procedures-and-treatments/coronary-chronic-total-occlusion-system.html (last accessed Sep. 10, 2015); see also, U.S. Pat. Nos. 8,632,556, 8,202,246, 8,636,712, 8,721,675, 6,511,458.

The CrossBoss™ catheter can be first used to facilitate the crossing a CTO as simply bluntly dissecting via small micro channels within the vessel through the occlusion or if this is not successful in crossing, the device can navigate from the subintimal space of a vascular wall. As an illustration,FIG. 1Ashows a schematic representation of a CrossBoss™ catheter100, which includes a rounded/blunt distal tip108mounted to a flexible proximal shaft120which is torquable through rotation of the handle130, the shaft120having a lumen which accommodates a guidewire102.

The Stingray™ catheter, Stingray™ Guidewire can be used subsequent to the CrossBoss™ catheter to facilitate orienting and steering a guidewire or reentry device from the subintimal space into the true lumen of an artery. As an illustration,FIG. 1Bshows a schematic representation of a Stingray™ catheter having a distally positioned laterally inflatable balloon210and a proximal shaft220having a central guidewire lumen225. The side-ports212and214are located on opposite sides of a portion of the central lumen flanked by the balloon210and identified by radiopaque markers232and234. The side ports212and214communicate with the central guidewire lumen225and facilitate the steering of the reentry device240with a pre-biased tip (at an angle to the central lumen) by allowing the tip of the Stingray™ Guidewire reentry device240to exit from the catheter from one of the side ports.

The CrossBoss™ catheter can be used to pass through the proximal cap of a CTO by rotation of the blunt tip. However, if this is not successful, a procedure employing both the CrossBoss™ and Stingray™ catheters to cross the CTO would be needed. The procedure can be generally described as follows.

(1) advancing the CrossBoss™ catheter over a guidewire to an interface between the catheter distal tip and surrounding tissue;

(2) penetrating the catheter tip into the vascular wall and advancing the CrossBoss™ device within the vascular wall to establish a channel in the subintimal space of the vascular wall such that the tip extends longitudinally across the occlusion;

(3) withdrawing the CrossBoss™ catheter over the guidewire;

(4) advancing the Stingray™ catheter over the guidewire;

(5) inflating the balloon of the Stingray™ catheter to cause the Stingray™ balloon to assume one of two orientations;

(6) withdrawing the guidewire from the Stingray™ catheter;

(7) advancing a reentry device having a pre-configured tip portion in a compressed state into the lumen of the Stingray™ catheter; and

(8) manipulating the tip of the reentry device with the aid of radiographic visualization such that the tip of the reentry device exits from one side port of the Stingray™ catheter in a natural state and into the lumen of the artery (true lumen).

The Stingray™ catheter can then be withdrawn, leaving the reentry device in place which establishes a pathway from the proximal segment of the vascular lumen and the distal segment of the vascular lumen, over which a balloon catheter can be subsequently introduced and deployed at the site of the CTO. A stent can be further implanted at the site which has been expanded by the balloon.

While the above procedure of subintimal crossing using a combination of CrossBoss™ and Stingray™ catheters overcame certain difficulties of previous generation techniques in direct antegrade CTO access, the procedure is complex and time-consuming. Furthermore, switching from CrossBoss™ to Stingray™ can introduce unintended errors. For example, withdrawing the CrossBoss™ catheter from the guidewire (so that the Stingray™ catheter may be introduced over the guidewire) may cause the guidewire to shift position in the subintimal space, or worse, to retract from the subintimal space, in which case the operator would not be able to properly introduce the Stingray™ catheter over the guidewire into the subintimal space. As a result, the previous step of using CrossBoss™ catheter to cross the subintimal space would need to be repeated. Additionally, advancing and inflating the distal balloon of the Stingray™ catheter in the subintimal space can create excessive delamination and substantial trauma in the layers of the vascular wall.

It would be desirable to provide devices and methods for treatment of vascular conditions associated by crossing a CTO in a blood vessel by exploring the subintimal space in a more simplified procedure with reduced error rate and reduced trauma to the blood vessel.

SUMMARY OF THE INVENTION

In one aspect, the present invention provides a catheter device. The catheter device includes a distal catheter tube portion having a longitudinal axis and including a tube wall comprising at least one side port, at least one radiopaque marker, and at least one wing protruding radially outward from the tube wall.

In some embodiments, the tube wall includes two wings protruding radially outward in diametrically opposing directions. In certain of these embodiments, wherein the at least one side port is radially offset from each of the two wings for about 90 degrees. In specific embodiments, the first side port and the second side port are radially offset for about 180° degrees from each other.

In some embodiments, the at least one side port is beveled.

In some embodiments, the catheter device includes a radiopaque marker affixed on the distal catheter tube portion in axial alignment with the at least one side port. In other embodiments, the catheter device includes a radiopaque marker encircling the at least one side port.

In some embodiments, the tube wall includes a first side port and a second side port which is longitudinally and radially offset from the first side port, the second side port being located distal the first side port. In certain of these embodiments, the tube wall comprises a first radiopaque marker located longitudinally between the first side port and the second side port, and a second radiopaque marker distal the second side port.

In some embodiments, the at least one wing is part of a guide-tip engaging a distal end of the catheter. In other embodiments, the at least one wing can be placed in a distance from the distal end of the catheter.

In some embodiments, the catheter device includes at least one spiral-cut section, and the at least one side port is located in the spiral-cut section.

In certain embodiments, the catheter device includes at least two spiral-cut sections having different pitches.

In some embodiments, the catheter device includes at least one spiral-cut section with interrupted spirals.

In certain embodiments, the catheter device includes at least two interrupted spiral-cut sections having different pitches.

The at least one wing can be formed from a polymeric material, a metal, or a composite material.

In another aspect, the present invention provides a method for facilitating treatment of an occlusion in a blood vessel with a catheter device as described herein. The blood vessel has a vascular wall defining a vascular lumen containing an occlusion therein. The occlusion separates the vascular lumen into a proximal segment and a distal segment. The catheter device has a lumen and includes a distal catheter tube portion including a tube wall comprising at least one side port and at least one radiopaque marker, and a guide-tip located at a distal end of the catheter, where the guide-tip includes at least two wings protruding radially outward in diametrically opposing directions. The method includes: positioning the catheter device proximate the occlusion; advancing the guide-tip within the vascular wall adjacent the occlusion until the at least one side port is positioned distal of the occlusion to establish a channel in the vascular wall extending longitudinally across the occlusion; orienting the at least one side port toward the vascular lumen; inserting a re-entry device through the lumen of the catheter device wherein the re-entry device has a distal end portion in a compressed state; and manipulating the re-entry device such that a distal end portion of the re-entry device exits, in a natural state, from the at least one side port into the distal segment of the vascular lumen.

