The present disclosure relates to treatment of stenosis in a body vessel and in particular to catheters and methods for crossing a chronic total occlusion in a blood vessel.
Coronary artery disease (“CAD”) is the leading cause of death in the United States. One method for treating atherosclerosis and other forms of arterial lumen narrowing is percutaneous transluminal angioplasty, commonly referred to as “angioplasty” or “PTA,” or “PTCA” when performed in the coronary arteries. The objective in angioplasty is to restore adequate blood flow through the affected artery, which may be accomplished by inflating a balloon of a balloon catheter within the narrowed lumen of the artery to dilate the vessel. Similarly, Peripheral vascular disease (“PVD”) is an epidemic that is impacting millions of patients worldwide. The number of patients suffering from PVD is expected to increase by 15% in the western countries and 30% in the developing countries. Endovascular revascularization of patients with CAD and PVD is becoming a common modality of treatment in these patients.
The accompanying drawings, which are included to provide further understanding of the subject technology and are incorporated in and constitute a part of this description, illustrate aspects of the subject technology and, together with the specification, serve to explain principles of the subject technology.
In the following detailed description, specific details are set forth to provide an understanding of the subject technology. It will be apparent, however, to one ordinarily skilled in the art that the subject technology may be practiced without some of these specific details. In other instances, well-known structures and techniques have not been shown in detail so as not to obscure the subject technology.
Chronic total occlusion (“CTO”) is a term that describes an occlusion of the arterial conduit. The penetration of an occlusion in arteries or veins depends on the use of catheters and wires. A wire has to be across the occlusion to deliver revascularization therapy. The wire has to be directed from a patent segment of the vessel before the occlusion to another patent segment of the vessel after the occlusion. One challenge is to direct the wire from true lumen to true lumen. Commonly, all wires and traditional catheters will be directed into the subintimal plane. This area is not part of the true vessel and the physician has to direct the catheter with the wire to the true lumen. A common scenario is the wire leaving the vessel and becoming extra vascular. Long CTO's tend to be difficult to cross. The biggest obstacle to CTO crossing is subintimal position of any crossing device. The operator must enter into the true lumen of the vessel. One challenge is guiding a wire into the true lumen of the vessel. Most CTO crossing devices and wires/loop technique creates a large subintimal plane or become extra luminal making re-entry into the true lumen a difficult task.
According to some embodiments, a subintimal entry catheter can be used for crossing an occlusion. A treatment system 10, such as the one shown in
A catheter 40 can be used for crossing a occlusion. As shown in
In use, an operator can use the guide catheter to position the catheter 40 in a patient's vasculature. This procedure can involve inserting the guide catheter into the patient's vasculature through an access point such as the groin, and directing the distal portion of the guide catheter through the vascular system (e.g., with a guide wire) until it reaches the target vessel. After removing a guide wire from the guide catheter, the catheter 40 can be inserted into the guide catheter. As the distal end portion 90 of the catheter 40 exits the guide catheter, it can be positioned near the target site, such as an occlusion.
The catheter 40 can include features, such as a distal end portion 90 to act on the occlusion. For example, the distal end portion 90 can be rigid and shaped to facilitate entry. For example, the distal end portion 90 can be more rigid than the more proximal body of the catheter 40. The distal end portion 90 can be metal and tapered (e.g., conical or hemispherical shaped). Additionally or alternatively, the guide catheter can have ridges 92 and/or protrusions that extend helically along an outer surface thereof, to facilitate axial movement relative to a occlusion based on rotational action of the guide catheter. The ridges 92 and/or protrusions can be created in an angulated or horizontal fashion. By rotating the catheter 40 (e.g., with a torque device 50), the distal end portion 90 can be propelled through the occlusion or other materials, including tissue. The low profile nature of the catheter 40 can help it stay within the subintimal space. In case the device crosses into a subintimal plane, the catheter 40 can maintain proximity to the true lumen of the vessel. The ridges 92 can extend in a clockwise and/or counter-clockwise orientation. Variation in the angle of ridges is contemplated. One or more of the ridges 92 can be parallel to each other. The function of the ridges 92 can facilitate plaque penetration while controlling propulsion of the device. Additionally or alternatively, the distal end portion 90 can include a smooth surface. Additionally or alternatively, the distal end portion 90 can include a rough surface.
As shown in
As shown in
As shown in
Once the side is directed toward the true lumen, a wire can be advanced and penetrate the subintimal plane to the true lumen. At this stage, the catheter can follow the wire, thus achieving the objective of having a wire connecting the true lumen of the vessel to the true lumen of the vessel on opposite sides of the occlusion.
As shown in
In use, while the balloon 60 is flat (e.g., deflated), it will not impact advancing the catheter with the distal end portion 90. This can allow the distal end portion 90 to be advanced with a guide catheter. The balloon 60 inflation profile can allow for eccentric deflection. When inflated, the balloon 60 can expand to the side of the distal end portion 90. This can allow the distal end portion 90 to be pushed toward the true lumen of the vessel. Once the opening 82 is oriented toward the true lumen of the vessel, the operator may inflate the balloon 60 with an inflation medium (e.g., fluid) provided from the handle via an inflation lumen in fluid communication with the balloon 60. Inflating the balloon can allow the distal end portion 90 to be pushed closer to the true lumen of the vessel. If the opening 82 is closer to the true lumen of the vessel, advancing a wire into the true lumen can be easier. For example, the distance between the subintimal plane and the true lumen becomes smaller, and the wire advanced from inside the catheter to the true lumen of the vessel can travel a shorter distance.
The expansion member can include other or additional mechanisms. For example, a self-expanding spring (e.g., Nitinol) or other elastic structure can be provided opposite to the opening 82. The elastic structure can be initially sheathed in a compressed state. The elastic structure can be unsheathed with a release mechanism from the handle. Once released, it can allow the distal end portion 90 to be pushed in a direction away from the direction in which it is facing. In use, the operator can point the opening 82 toward the lumen of the vessel. Once the elastic structure is released, it can push the distal end portion 90 further toward the lumen of the vessel. The release mechanism located at the proximal end of the catheter can be a sliding cover that is controlled from the handle. Once pulled back, it can expose the elastic structure. If desired, it can advance over and collapse the elastic structure
Additionally or alternatively, features of the catheter 40 can be applied to another catheter (e.g., guide catheter) containing the catheter 40. For example, the expansion members can be incorporated onto the catheter 40 and/or a guide catheter containing the catheter 40. Deflection of the catheter 40 can be achieved, at least in part, by deflecting a guide catheter containing the catheter 40. By further example, markers can be incorporated onto the catheter 40 and/or a guide catheter containing the catheter 40. Orientation of the catheter 40 can be achieved, at least in part, by arranging the guide catheter in a desired orientation.
It may be undesired, difficult or impossible to pass directly through a occlusion in a lumen of a blood vessel to recanalize the vessel. In such instances, it may be possible to recanalize the blood vessel through a subintimal approach using the catheter 40. Turning to
The blood vessel 180 typically has three tissue layers, an innermost layer or intima layer (i.e., tunica intima) 182, an intermediate layer or media layer (i.e., tunica media) 184, and an outermost layer or adventitia layer (tunica adventitia) 186, with the media layer 184 positioned between the intima layer 182 and the adventitia layer 186. The intima layer 182 is a layer of endothelial cells lining the lumen 188 of the vessel 180, as well as a subendothelial layer made up of mostly loose connective tissue. The media layer 184 is a muscular layer formed primarily of circumferentially arranged smooth muscle cells. The adventitia layer 186, which forms the exterior layer of the vessel wall 180 is formed primarily of loose connective tissue made up of fibroblasts and associated collagen fibers. As will be described further herein, the distal end portion 90 can be advanced into a subintimal space (i.e., a space between the intima layer 182 and the adventitia layer 186) created in the vessel wall 180, such as through dissection of the tissue layers of the vessel wall 180.
As shown in
As shown in
As shown in
As shown in
As shown in
As shown in
One or more of a variety of therapies can be facilitated by the position of the wire 70. As shown in
As shown in
It will be understood that the alignment and orientation of catheters (e.g., distal end portions and openings) can be achieved in a variety of locations. As shown in
The antegrade catheter 40 and the retrograde catheter 240 may approach the occlusion 190 from opposite sides (e.g., proximal and distal) thereof within the true lumen 188 of the vessel 180. Accordingly, the wire or another device can span the occlusion 190 including across opposing sides (e.g., caps) thereof. Additionally or alternatively, the antegrade catheter 40 and the retrograde catheter 240 may approach the occlusion 190 from the same side (e.g., proximal or distal) within the true lumen 188 of the vessel 180. For example, the wire or another device can span a portion of the occlusion 190 and return to the same side (e.g., cap) of its approach. By further example, the wire or another device can extend about the occlusion 190 and return to the same side (e.g., cap) of its approach.
Alignment of openings for two separate catheters can be facilitated by magnetic couplings across the catheters. As shown in
As shown in
The first magnetic element 58 is within the distal end portion 90 at or near the terminal end thereof. The second magnetic element 258 is within the distal end portion 290 at or near the terminal end thereof. The first magnetic element 58 and/or the second magnetic element 258 can include a temporary magnet of a soft magnetic material or a permanent magnet of a hard magnetic material. As used herein, “magnet” can include a magnet of a hard magnetic material and/or a magnet of a soft magnetic material. Hard magnetic materials include materials that retain their magnetism even after the removal of an applied magnetic field. Magnets that include hard magnetic material can form permanent magnets. Hard magnetic materials include neodymium (NdFeB), iron-neodymium, iron-boron, cobalt-samarium, iron-chromium-cobalt, and combinations or alloys thereof. Soft magnetic materials include materials that are responsive to magnetic fields, but do not retain their magnetism after removal of an applied magnetic field. Magnets that include soft magnetic material can form temporary magnets. Soft magnetic materials include iron, iron-cobalt, iron-silicon, steel, stainless steel, iron-aluminum-silicon, nickel-iron, ferrites, and combinations or alloys thereof. It will be recognized that “hard magnetic” and “soft magnetic” does not necessarily relate to the rigidity of the materials. Additionally or alternatively, the first magnetic element 58 and/or the second magnetic element 258 can form an electromagnet. The electromagnet can be controllably activated by an operator when desired by providing an electrical current to the electromagnet. The magnitude of the magnetic attraction can be controlled by operation of the electromagnet.
As shown
The magnetic elements 58 and 258 can be oriented to facilitate the magnetic attraction and coupling. For example, the polarities of the magnetic elements 58 and 258 can be aligned so that the opposing distal end portions 90 and 290 are magnetically attracted to each other.
Various magnet arrangements and configurations can be provided to achieve the functionality discussed herein. As shown in
As shown in
The magnetic attraction and alignment discussed herein can be applied to the other methods illustrated and discussed herein. For example, magnetic elements can be aligned and/or activated during an alignment of opening, such as that illustrated in
Additionally or alternatively, other devices, such as a magnetic snare, can be used to magnetically couple to one or more of the catheters. The snare can be magnetic such that it magnetically couples to magnetic elements of a catheter. Additional operations, such as adjustments and/or retrieval can be performed with the magnetic snare.
The apparatuses and methods discussed herein are not limited to treatment of any particular vessels, but may include any number of different types of vessels. For example, in some aspects, vessels may include arteries or veins. The vessels may have bifurcations and/or sharp turns. In some aspects, the vessels may be suprathoracic vessels (e.g., vessels in the neck or above), intrathoracic vessels (e.g., vessels in the thorax), subthoracic vessels (e.g., vessels in the abdominal area or below), lateral thoracic vessels (e.g., vessels to the sides of the thorax such as vessels in the shoulder area and beyond), or other types of vessels and/or branches thereof.
In some aspects, the suprathoracic vessels may comprise at least one of intracranial vessels, cerebral arteries, and/or any branches thereof. For example, the suprathoracic vessels may comprise at least one of a common carotid artery, an internal carotid artery, an external carotid artery, a middle meningeal artery, superficial temporal arteries, an occipital artery, a lacrimal (ophthalmic) artery, an accessory meningeal artery, an anterior ethmoidal artery, a posterior ethmoidal artery, a maxillary artery, a posterior auricular artery, an ascending pharyngeal artery, a vertebral artery, a left middle meningeal artery, a posterior cerebral artery, a superior cerebellar artery, a basilar artery, a left internal acoustic (labyrinthine) artery, an anterior inferior cerebellar artery, a left ascending pharyngeal artery, a posterior inferior cerebellar artery, a deep cervical artery, a highest intercostal artery, a costocervical trunk, a subclavian artery, a middle cerebral artery, an anterior cerebral artery, an anterior communicating artery, an ophthalmic artery, a posterior communicating artery, a facial artery, a lingual artery, a superior laryngeal artery, a superior thyroid artery, an ascending cervical artery, an inferior thyroid artery, a thyrocervical trunk, an internal thoracic artery, and/or any branches thereof. The suprathoracic vessels may also comprise at least one of a medial orbitofrontal artery, a recurrent artery (of Heubner), medial and lateral lenticulostriate arteries, a lateral orbitofrontal artery, an ascending frontal (candelabra) artery, an anterior choroidal artery, pontine arteries, an internal acoustic (labyrinthine) artery, an anterior spinal artery, a posterior spinal artery, a posterior medial choroidal artery, a posterior lateral choroidal artery, and/or branches thereof. The suprathoracic vessels may also comprise at least one of perforating arteries, a hypothalamic artery, lenticulostriate arteries, a superior hypophyseal artery, an inferior hypophyseal artery, an anterior thalamostriate artery, a posterior thalamostriate artery, and/or branches thereof. The suprathoracic vessels may also comprise at least one of a precentral (pre-Rolandic) and central (Rolandic) arteries, anterior and posterior parietal arteries, an angular artery, temporal arteries (anterior, middle and posterior), a paracentral artery, a pericallosal artery, a callosomarginal artery, a frontopolar artery, a precuneal artery, a parietooccipital artery, a calcarine artery, an inferior vermian artery, and/or branches thereof.
In some aspects, the suprathoracic vessels may also comprise at least one of diploic veins, an emissary vein, a cerebral vein, a middle meningeal vein, superficial temporal veins, a frontal diploic vein, an anterior temporal diploic vein, a parietal emissary vein, a posterior temporal diploic vein, an occipital emissary vein, an occipital diploic vein, a mastoid emissary vein, a superior cerebral vein, efferent hypophyseal veins, infundibulum (pituitary stalk) and long hypophyseal portal veins, and/or branches thereof.
The intrathoracic vessels may comprise the aorta or branches thereof. For example, the intrathoracic vessels may comprise at least one of an ascending aorta, a descending aorta, an arch of the aorta, and/or branches thereof. The descending aorta may comprise at least one of a thoracic aorta, an abdominal aorta, and/or any branches thereof. The intrathoracic vessels may also comprise at least one of a subclavian artery, an internal thoracic artery, a pericardiacophrenic artery, a right pulmonary artery, a right coronary artery, a brachiocephalic trunk, a pulmonary trunk, a left pulmonary artery, an anterior interventricular artery, and/or branches thereof. The intrathoracic vessels may also comprise at least one of an inferior thyroid artery, a thyrocervical trunk, a vertebral artery, a right bronchial artery, a superior left bronchial artery, an inferior left bronchial artery, aortic esophageal arteries, and/or branches thereof.
In some aspects, the intrathoracic vessels may also comprise at least one of a right internal jugular vein, a right brachiocephalic vein, a subclavian vein, an internal thoracic vein, a pericardiacophrenic vein, a superior vena cava, a right superior pulmonary vein, a left brachiocephalic vein, a left internal jugular vein, a left superior pulmonary vein, an inferior thyroid vein, an external jugular vein, a vertebral vein, a right highest intercostal vein, a 6th right intercostal vein, an azygos vein, an inferior vena cava, a left highest intercostal vein, an accessory hemiazygos vein, a hemiazygos vein, and/or branches thereof.
In some aspects, the subthoracic vessels may comprise at least one of renal arteries, inferior phrenic arteries, a celiac trunk with common hepatic, left gastric and splenic arteries, superior suprarenal arteries, a middle suprarenal artery, an inferior suprarenal artery, a right renal artery, a subcostal artery, 1st to 4th right lumbar arteries, common iliac arteries, an iliolumbar artery, an internal iliac artery, lateral sacral arteries, an external iliac artery, a testicular (ovarian) artery, an ascending branch of deep circumclex iliac artery, a superficial circumflex iliac artery, an inferior epigastric artery, a superficial epigastric artery, a femoral artery, a ductus deferens and testicular artery, a superficial external pudendal artery, a deep external pudendal artery, and/or branches thereof. The subthoracic vessels may also comprise at least one of a superior mesenteric artery, a left renal artery, an abdominal aorta, an inferior mesenteric artery, colic arteries, sigmoid arteries, a superior rectal artery, 5th lumbar arteries, a middle sacral artery, a superior gluteal artery, umbilical and superior vesical arteries, an obturator artery, an inferior vesical and artery to ductus deferens, a middle rectal artery, an internal pudendal artery, an inferior gluteal artery, a cremasteric, pubic (obturator anastomotic) branches of inferior epigastric artery, a left colic artery, rectal arteries, and/or branches thereof.
In some aspects, the lateral thoracic vessels may comprise at least one of humeral arteries, a transverse cervical artery, a suprascapular artery, a dorsal scapular artery, and/or branches thereof. The lateral thoracic vessels may also comprise at least one of an anterior circumflex humeral artery, a posterior circumflex humeral artery, a subscapular artery, a circumflex scapular artery, a brachial artery, a thoracodorsal artery, a lateral thoracic artery, an inferior thyroid artery, a thyrocervical trunk, a subclavian artery, a superior thoracic artery, a thoracoacromial artery, and/or branches thereof.
The apparatus and methods discussed herein are not limited to the deployment and use of a balloon or stent within the vascular system but may include any number of further treatment applications. Other treatment sites may include areas or regions of the body such as organ bodies.
Various examples of aspects of the disclosure are described below as clauses for convenience. These are provided as examples, and do not limit the subject technology.
Clause A. A catheter comprising: a distal end portion; a lumen extending longitudinally within the catheter and radially to an opening in a first radial side at the distal end portion of the catheter; and an inflatable balloon on a second radial side at the distal end portion of the catheter, opposite the first radial side, the inflatable balloon configured to expand radially away from the lumen when expanded.
Clause B. A system, comprising: a first catheter comprising: a first lumen extending longitudinally within the first catheter to an opening in a first end portion of the first catheter; and a first magnetic element at the first end portion; and a second catheter comprising: a second lumen extending longitudinally within the second catheter to an opening in a second end portion of the second catheter; and a second magnetic element at the second end portion, wherein the first magnetic element and the second magnetic element are configured to attract each other and align the first opening with the second opening.
Clause C. A method comprising: positioning a first catheter on a first side of an occlusion within a body vessel; advancing a first end portion of the first catheter into a subintimal tissue adjacent to the occlusion; positioning a second catheter on a second side of the occlusion; advancing a second end portion of the second catheter into the subintimal tissue; and advancing a wire through a lumen of the first catheter, out of a first opening of the first catheter, and into a second opening of the second catheter while the first opening is facing the second opening.
Clause D. A method comprising: positioning a catheter in a region of a body vessel on a first side of an occlusion; advancing an end portion of the catheter into a subintimal tissue adjacent to the occlusion and to a region of the subintimal tissue adjacent to a region of the body vessel on a second side of the occlusion; positioning an opening in a first radial side of the end portion to face body vessel; inflating a balloon on a second radial side of the end portion, opposite the first radial side, such that the end portion is deflected toward the body vessel; and advancing a wire out of the opening and into the body vessel while the end portion is within the subintimal tissue.
Clause E. A catheter comprising: a distal end portion; a lumen extending longitudinally within the catheter and radially to a port in a radial side at the distal end portion of the catheter; and at least three radiopaque markers axially aligned with the port, wherein one of the radiopaque markers has an a radially asymmetric shape.
In one or more aspects, the catheters, systems, and/or method of any preceding paragraph, either alone or in combination, can further include one or more features of the additional clauses described below.
Element 1. the catheter is a first catheter, the distal end portion is a first distal end portion, the lumen is a first lumen, and the opening is a first opening; and a second catheter comprising: a second distal end portion; and a second lumen extending longitudinally within the second catheter and radially to a second opening in a third radial side at the second distal end portion of the second catheter, wherein the second opening is larger than the first opening.
Element 2. the balloon is axially aligned with the opening.
Element 3. at least three radiopaque markers axially aligned with the opening, wherein one of the radiopaque markers has a radially asymmetric shape.
Element 4. the radially asymmetric shape is a triangle.
an end of the radially asymmetric shape points radially toward the opening.
Element 5. at least two of the radiopaque markers have different shapes.
Element 6. at least two of the radiopaque markers have the same shape.
Element 7. the first magnetic element forms an annular ring that surrounds the first opening, and the second magnetic element forms an annular ring that surrounds the second opening.
Element 8. the first opening forms a first terminal end of the first catheter that is transverse to a longitudinal axis of the first catheter, and the second opening forms a second terminal end of the second catheter that is transverse to a longitudinal axis of the second catheter.
Element 9. the first magnetic element comprises multiple magnets on opposite radial sides of a longitudinal axis of the first catheter, and the second magnetic element comprises multiple magnets on opposite radial sides of a longitudinal axis of the second catheter.
Element 10. each of the first magnetic element and the second magnetic element comprises an electromagnet.
Element 11. the advancing comprises advancing the wire until a first portion of the wire is in the body vessel on a first side of the occlusion, a second portion of the wire is within the subintimal tissue, and a third portion of the wire is in the body vessel on the second side of the occlusion.
Element 12. removing the first catheter and the second catheter from the subintimal tissue without removing the wire from the subintimal tissue.
Element 13. advancing a device along the wire from a first side of the occlusion, through the subintimal tissue, to a second side of the occlusion.
Element 14. providing a channel through the subintimal tissue for fluid flow between the first side of the occlusion and the second side of the occlusion.
Element 15. advancing the second end portion comprises aligning the first opening of the first end portion with the second opening of the second end portion.
Element 16. the aligning comprises allowing a first magnetic element of the first end portion to attract to a second magnetic element of the second end portion.
The foregoing description is provided to enable a person skilled in the art to practice the various configurations described herein. While the subject technology has been particularly described with reference to the various figures and configurations, it should be understood that these are for illustration purposes only and should not be taken as limiting the scope of the subject technology.
There may be many other ways to implement the subject technology. Various functions and elements described herein may be partitioned differently from those shown without departing from the scope of the subject technology. Various modifications to these configurations will be readily apparent to those skilled in the art, and generic principles defined herein may be applied to other configurations. Thus, many changes and modifications may be made to the subject technology, by one having ordinary skill in the art, without departing from the scope of the subject technology.
It is understood that the specific order or hierarchy of steps in the processes disclosed is an illustration of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the processes may be rearranged. Some of the steps may be performed simultaneously. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented.
A phrase such as “an aspect” does not imply that such aspect is essential to the subject technology or that such aspect applies to all configurations of the subject technology. A disclosure relating to an aspect may apply to all configurations, or one or more configurations. An aspect may provide one or more examples of the disclosure. A phrase such as “an aspect” may refer to one or more aspects and vice versa. A phrase such as “an embodiment” does not imply that such embodiment is essential to the subject technology or that such embodiment applies to all configurations of the subject technology. A disclosure relating to an embodiment may apply to all embodiments, or one or more embodiments. An embodiment may provide one or more examples of the disclosure. A phrase such “an embodiment” may refer to one or more embodiments and vice versa. A phrase such as “a configuration” does not imply that such configuration is essential to the subject technology or that such configuration applies to all configurations of the subject technology. A disclosure relating to a configuration may apply to all configurations, or one or more configurations. A configuration may provide one or more examples of the disclosure. A phrase such as “a configuration” may refer to one or more configurations and vice versa.
As used herein, the phrase “at least one of” preceding a series of items, with the term “and” or “or” to separate any of the items, modifies the list as a whole, rather than each member of the list (i.e., each item). The phrase “at least one of” does not require selection of at least one of each item listed; rather, the phrase allows a meaning that includes at least one of any one of the items, and/or at least one of any combination of the items, and/or at least one of each of the items. By way of example, the phrases “at least one of A, B, and C” or “at least one of A, B, or C” each refer to only A, only B, or only C; any combination of A, B, and C; and/or at least one of each of A, B, and C.
Terms such as “top,” “bottom,” “front,” “rear” and the like as used in this disclosure should be understood as referring to an arbitrary frame of reference, rather than to the ordinary gravitational frame of reference. Thus, a top surface, a bottom surface, a front surface, and a rear surface may extend upwardly, downwardly, diagonally, or horizontally in a gravitational frame of reference.
Furthermore, to the extent that the term “include,” “have,” or the like is used in the description or the claims, such term is intended to be inclusive in a manner similar to the term “comprise” as “comprise” is interpreted when employed as a transitional word in a claim.
The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.
A reference to an element in the singular is not intended to mean “one and only one” unless specifically stated, but rather “one or more.” Pronouns in the masculine (e.g., his) include the feminine and neuter gender (e.g., her and its) and vice versa. The term “some” refers to one or more. Underlined and/or italicized headings and subheadings are used for convenience only, do not limit the subject technology, and are not referred to in connection with the interpretation of the description of the subject technology. All structural and functional equivalents to the elements of the various configurations described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and intended to be encompassed by the subject technology. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the above description.
While certain aspects and embodiments of the subject technology have been described, these have been presented by way of example only, and are not intended to limit the scope of the subject technology. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms without departing from the spirit thereof. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the subject technology.
This application claims the benefit of U.S. Provisional Application No. 62/508,961, entitled “SUBINTIMAL ENTRY CATHETERS AND METHODS FOR OCCLUSION CROSSING,” filed May 19, 2017, the entirety of which is incorporated herein by reference.
Number | Date | Country | |
---|---|---|---|
62508961 | May 2017 | US |