Flow arrest liquid embolic catheter and methods of use

Abstract

A catheter is operated to longitudinally compress and radially expand an ePTFE ribbon so as to create an occlusion in a blood vessel, at least inhibiting reflux of liquid embolic when injected through the catheter so as to create a distal flow of the embolic through the vessel. The catheter comprises a smaller inner catheter tube coaxially positioned with a surrounding, larger outer catheter tube. A longitudinally disposed segment of ePTFE may optionally be bonded at or proximal to a tip of the inner catheter at a first end thereof, and a second end of the ePTFE is optionally bonded as well at or proximate to a corresponding tip of the outer catheter. In operation, the distal tip of the inner catheter is placed proximate to a desired treatment location and then withdrawn within the outer catheter, thereby corrugating, or generally crumpling, the ePTFE ribbon creating a "crumple zone" serving to at least partially occlude the blood vessel. A liquid embolic may then be injected through the working lumen of the inner catheter thereafter to achieve a more permanent occlusion of the vessel anomaly being treated, while the crumple zone inhibits reflux of the embolic agent.

Description

[0001] FLOW ARREST LIQUID EMBOLIC CATHETER AND

[0002] METHODS OF USE

[0003] INVENTOR: Jared Hutar

[0004] BACKGROUND OF THE INVENTION

[0005] The present invention relates to systems and methods of arresting flow through a vessel ahead of a a treatment location of a vascular abnormality of a patient.

[0006] One example of such lesion or otherwise anomalous formation comprises an arteriovenous malformation (AVM). An AVM is an abnormal tangle of blood vessels connecting arteries and veins, resulting in a disruption of a normal oxygen supply to the brain. In particular, these abnormal vessels can prevent oxygen from being effectively carried to and from the brain. Additionally, if the AVM happens to rupture, it can cause hemorrhaging, stroke, or immanent brain damage.

[0007] Heretofore, the main treatment for an AVM had been surgery. One type of treatment approach has included insertion of a catheter into the site of the AVM, and has usually comprised occluding or arresting the flow of liquid through the vessel into which the catheter is inserted. The methods currently implemented by the conventional art include injection of copolymers which, upon release, solidify to occlude the vessel.

[0008] Current procedures for the treatment of Arteriovenous malformation (AVM) include the injection of a liquid embolic, intended to cut off the proximal flow of blood to the AVM. This type of operation consists of filling the whole anomalous cluster with the liquid embolic to form a new pathway.

[0009] Liquid embolics such as glues or copolymers and the like adhere to the vessel wall and solidify inwardly. A drawback of the conventional treatment lies in the fact that the resistance from smaller diameter blood vessels may cause the liquid embolic to backflow (reflux) into larger vessels instead of reliably into the AVM, thus failing to properly occlude the desired defective vessels.

[0010] Remedies to this deficiency have heretofore included temporary occlusion of the vessels behind the injection point of the liquid embolic to prevent backflow, a phenomenon otherwise referred to as “reflux.” Conventional systems and methods accomplish temporary occlusion behind an injection point generally through the use of a balloon catheter.

[0011] Balloon catheters of the size needed for this procedure are very small, which makes them highly fragile and expensive to produce.

[0012] These copolymer-based operations come with risks and flaws due to the nature of chemical processes occurring in the body. Thus, there is a need for systems and methods to remedy these deficiencies found in the conventional art

[0013] It would therefore be desirable to provide an elongated flexible membrane which reinforces itself while collapsing, thus adding radial strength, while concomitantlyresuiting in a muchreduced manufacturing cost and accomplishing more reliable occlusion at least partially inhibiting reflux behind an embolic injection point.

[0014] SUMMARY OF THE INVENTION

[0015] In accordance with these and other objects of the invention, there is provided a catheter comprising a first elongate flexible tube having a first lumen and including a first distal tip, and a second elongate flexible tube, having a working lumen and including a second distal tip extending beyond the first distal tip. The second elongate tube is positioned coaxially within, and lying generally coextensively, with the first elongate flexible tube.

[0016] According to an embodiment of the invention, the catheter comprises an extended polytetrafluoroethylene (ePTFE) segment, generally provided in the form of a flexible ribbon, and having a first end and a second end; the first end being attached to the first elongate flexible tube at or proximate the first distal tip and the second end being attached to the second elongate flexible tube at or proximate the second distal tip. In a non-compressed state adapted for initial insertion into a delivery blood vessel, the second elongate flexible tube extends in a generally flattened state a first distance past the distal end of the first elongate flexible tube, thereby forming a longitudinal extent of the flexible ribbon prior to being longitudinally compressed by relative movement between the first and second elongate tubes in a direction which shortens the first distance to a second shortened distance. When moved to the second shortened distance, the ribbon, advantageously comprised of ePTFE creates a crumple zone between the first and second distal tips.

[0017] As defined herein, the term “crumple zone” defines an altered geometry of the generally flat ribbon after a longitudinally compressed deformation thereof created by a relative reorientation of the first and second tubes, creating any of a corrugation, folding, compressive radial expansion, bunched or any of similar longitudinally shortened reconfiguration of the ePTFE ribbon segment. The defined “crumple zone” is comprised of at least a compressed partial region or a substantial or complete entirely of the initial flattened extent of the ePTFE segment.

[0018] In operation, the first elongate flexible tube is advantageously configured to move, at least partially, over the second elongate flexible tube, so as to shorten a distance between the respective distal tips, when the distal tips are located proximate to a lesion in a vessel, such as for example, an AVM, through which the catheter is inserted. The resultant corrugation or other crumpling of the ePTFE segment, is effective to radially expand the ribbon segment in a thickness direction thereof, in turn providing an at least partial occlusion of the vessel ahead of the vascular anomaly, in correspondence with longitudinal crumpling of the ePTFE segment. This serves to at least inhibit reflux, and more preferably substantially completely preventing reflux, of the injected embolic fluid directed to a particular target vascular anomaly. In accordance with another advantageous embodiment, the first elongate flexible tube and the second elongate flexible tube each includes an inner diameter and an outer diameter, a liner neither being included around the inner nor outer diameters of the first and second elongate flexible tubes.

[0019] A method according to embodiment of the present invention is also described, and which includes occluding a vessel, the method comprising placing a catheter in a vessel leading to a lesion, wherein the catheter includes a first elongate flexible tube having a first lumen and including a first distal tip, a second elongate flexible tube, having a working lumen and including a second distal tip, and being positioned coaxially within and lying generally coextensively with the first elongate flexible tube, the second elongate flexible tube extending a distance past the first elongate flexible tube.

[0020] In accordance with an embodiment of the invention, the first and second elongate flexible tubes are optionally coupled together proximate the first and second distal tips by an extended polytetrafluoroethylene (ePTFE) segment, generally in the form of a flexible elongate ribbon tensioned longitudinally therebetween..

[0021] In accordance with an advantageous embodiment, the method of occluding a vessel comprises occluding the vessel by at least partially crumpling the ePTFE segment in connection with moving the first elongate flexible tube at least partially over the second elongate flexible tube so as to shorten a distance between the first and second distal tips, when located proximate to the lesion.

[0022] In accordance with an advantageous embodiment, the second distal tip includes ePTFE. The second distal tip may also include a hydrophilic coating.

[0023] A further optional method embodiment will further comprise providing digital access through the vessel by an insertion of the first elongate flexible tube therein. It is contemplated that according to embodiment of the invention, the vessel may be selected from the group consisting of an artery or a vein.

[0024] The method may further comprise injecting a liquid embolic through a lumen selected from the group consisting of the working lumen and the first lumen. In accordance with a particularly advantageous embodiment, the liquid embolic is optionally ethylene vinyl alcohol (EVOH).

[0025] The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings.

[0026] BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Features, aspects, and advantages are described below with reference to the drawings, which are intended to illustrate, but not to limit, the invention. In the drawings, like reference characters denote corresponding features consistently throughout similar embodiments.

[0028] Figure 1 illustrates a diagrammatic view of a flow arrest liquid embolic catheter within a patient, according to an embodiment of the invention, depicting by example only, an AVM malformation;

[0029] Figure 2 is a diagrammatic view of the flow arrest liquid embolic catheter positioned within a vessel, is a crumpled state;

[0030] Figure 3A depicts a profile view of the flow arrest liquid embolic catheter with the ePTFE ribbon oriented in a longitudinally extended and generally flattened form;

[0031] Figure 3B illustrates a profile view of the flow arrest liquid embolic catheter in a with the ePTFE ribbon oriented in a longitudinally crumpled (compressed corrugated) form; Figure 4A is a cross-sectional side view of the flow arrest liquid embolic catheter in an extended form;

[0032] Figure 4B illustrates a cross-sectional side view of the flow arrest liquid embolic catheter in a crumpled form;

[0033] Figure 4C depicts the process of crumpling or folding of the ePTFE segment shown in cross-section;

[0034] Figure 5 illustrates a cross-sectional front view of a catheter, according to an embodiment of the invention;

[0035] Figures 6A and 6B illustrate side views of a flow arrest liquid embolic catheter according toan embidment of the invention;

[0036] Figures 7A, 7B, and 7C depict perspective views of a flow arrest liquid embolic catheter, according to an embodiment of the invention;

[0037] Figures 8A, 8B, and 8C illustrate perspective views of a flow arrest liquid embolic catheter in a vessel;

[0038] Figure 9 is a perspective view of a flow arrest liquid embolic catheter after injecting an embolic in a vessel;

[0039] Figures 10A and 10B illustrate top views of a flow arrest liquid embolic catheter, according to an embodiment of the invention;

[0040] Figures 11 A and 1 IB illustrate cross-sectional views of a flow arrest liquid embolic catheter, according to some embodiments.

[0041] Figure 12 illustrates an optional demonstration of a flow arrest liquid embolic catheter in use; and

[0042] Figure 13 depicts an optional delivery housing for maintaining sterility of the catheter prior to insertion in a patient vessel. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0043] Figure 1 illustrates a diagrammatic view of the catheter 10 described herein as it may appear inside of a patient 42. Similarly, Figure 2 illustrates a closeup of the inset view from Figure 1 , illustrating the catheter 10 as it may appear within a vessel 28, directed by example for treating an arteriovenous malformation (AVM) 26.

[0044] With respect to Figure 2, the catheter 10 is shown when the ePTFE segment 20 comprises a crumple zone 24, shown in a compressed folded orientation. This crumple zone 24 as illustrated is effective to cause a temporary at least partial obstruction of blood flow through the vessel 28. Also, shown in greater detail, proximal to the ePTFE segment 20, are the distal tip 18a of the first elongate flexible tube 12a and a distal end 18b of the second elongate flexible tube 12b. The first elongate flexible tube 12a comprises a first lumen 14, which coaxially accommodates the second elongate flexible tube 12b. Additionally, the second elongate flexible tube 12b may comprise a working lumen 16, through which a liquid embolic may be delivered to facilitate permanent obstruction of the vessel 28.

[0045] The liquid embolic may be an ethylene-vinyl alcohol, such as for example ONYX ™ . Once the liquid embolic is injected, should there be a risk of reflux (undesired backward flow into vessels), the ePTFE segment 20 created crumple zone 24 will present a barrier, at least inhibiting or substantially preventing the reflux from occurring. This facilitates deeper penetration of the liquid embolic into a targeted lesion 26.

[0046] According to an advantageous embodiment, the first elongate flexible tube 12a is telescopically disposed about the second elongate flexible tube 12b. The second elongate flexible tube 12b is positioned coaxially within and lying generally coextensively with the first elongate flexible tube 12a. Figures 3 A and 4A illustrate views of the catheter 10 in an extended, generally flattened ribbon state such that the ePTFE segment 20 is not yet compressed to create crumple zone 24, as shown subsequently in Figures 3B and 4B, illustrating views of the catheter 10 in a longitudinally compressed (at least partially crumpled) orientation, such that the ePTFE segment 20 is creating a radially expanded crumple zone 24.

[0047] As shown in Figures 3A and 4A, the ePTFE segment 20 has a first end 22a and a second end 22b. The first end 22a is coupled to the first elongate flexible tube 12a, and the second end 22b may be coupled to the second elongate flexible tube 12b at or proximal their respective distal tips 18a and 18b. For reference, the distal tip of the first elongate flexible tube 12a is indexed as the first distal tip 18a, and the distal tip of the second elongate flexible tube 12b is indexed as the second distal tip 18b.

[0048] When the first distal tip 18a is positioned behind the second distal tip 18b such that the ePTFE segment 20 is extended in a generally flattened orientation, the profile of the catheter 10 is narrow enough to be directed through the vessels 28 of a patient being treated. When the first elongate flexible tube 12a is moved along the second elongate flexible tube 12b such that the first distal tip 18a moves closer to the second distal tip 18b, the ePTFE segment 20 begins to at least partially compress, creating crumple zone 24. This crumpling action creates the crumple zone 24 which temporarily occludes the vessel 28, as best seen in Figure 1.

[0049] After the procedure is completed (such as after the liquid embolic has been delivered and solidified), the first elongate flexible tube 12a is moved along the second elongate flexible tube 12b in an opposite direction, such that the first distal tip 18a returns at least partially to its starting position, thus extending the ePTFE segment 20 again into a generally flattened flexible ribbon for removal from the vessel 28. The process of compressing / crumpling of the ePTFE ribbon segment is shown in cross-section in Figure 4C.

[0050] Femoral and radial access may be used to gain access to, for example, a patient’s brain using the catheter 10 disclosed herein. The first elongate flexible tube 12a may be threaded in vessel 28 all the way to the lesion 26 or the second elongate flexible tube 12b, which is of a smaller cross-sectional diameter than the first elongate flexible tube 12a. The second elongate flexible tube 12b may pass through the first elongate flexible tube 12a to reach the lesion 26 as a consequence of the disposition between the first elongate flexible tube 12a and the second elongate flexible tube 12b.

[0051] In another advantageous application, the first elongate flexible tube 12a may be positioned through the femoral artery and placed in the internal carotid artery. From there, the first elongate flexible tube 12a maybe maneuvered into the middle cerebral artery or the anterior artery. Aspiration through the first elongate flexible tube 102 may occur thereafter, allowing a clot to be sucked out. Most guide catheters are too far away to help with suction, and generally do not provide aspiration. Conventional guide catheters normally only serve as a highway to a lesion.

[0052] According to a particularly advantageous embodiment, the first elongate flexible tube 12a has a cross-sectional diameter of 96 thousandths of an inch (larger than most conventional outer catheters which are typically 74 thousandths of an inch in cross-sectional diameter).

[0053] According to an advantageous embodiment of the invention, the first elongate flexible tube 12a is provided with a very soft tip. The first distal tip 18a and the second distal tip 18b may both be coated with this hydrophilic coating, such that the first distal tip 18a has a first hydrophilic coating and the second distal tip 18b has a second hydrophilic coating. The combination of the first elongate flexible tube 12a and the second elongate flexible tube 12b effectively provides two catheters (a larger diameter catheter and a smaller diameter catheter) that are packaged together.

[0054] In accordance with another embodiment, the first elongate flexible tube 12a is stiffer than the second elongate flexible tube 12b, and functions as a guide catheter. Most guide catheters, for a given internal carotid artery (ICA) application, only reach the proximal cervical ICA. Conventional guide catheters do not go any farther because the tip of the catheter isn’t soft enough to navigate the tortuous anatomy of the human body. As a consequence, guide catheters are typically relied upon for stiffness so that during a given procedure, stability is maintained in the ICA. Thereafter, in some applications, a soft distal access catheter, such as second elongate flexible tube 12b, is passed through first elongate flexible tube 12a (which functions as a guide catheter) to a lesion surface in order to get to a blood clot. Aspiration may occur through the second elongate flexible tube 12b, the inner catheter that is providing distal access.

[0055] Figure 5 illustrates a front view of the catheter 10 as a cross-section, as it may appear near the distal end. Variations in the diameters of the first elongate flexible tube 12a and the second elongate flexible tube 12b may be seen here. The first elongate flexible tube 12a has a first outer diameter 32a which is greater than its first inner diameter 30a. The space within the first inner diameter 30a comprises the first lumen 14. According to some embodiments, the second elongate flexible tube 12b is positioned through this first lumen 14.

[0056] The second elongate flexible tube 12b may likewise have an inner and outer diameter caused by thickness of the tube itself. Similar to the first elongate flexible tube 12a, the second elongate flexible tube may have a second outer diameter 32b that is greater that its second inner diameter 30b. The space within the second inner diameter 30b comprises the working lumen 16. In some embodiments, this working lumen 16 is the space through which a liquid embolic is injected into the treatment site, such as a lesion 26.

[0057] Also illustrated in Figure 5 is the ePTFE segment 20 as it may appear from a top perspective. As previously described, the ePTFE segment 20 has a first end 22a that is attached at or proximal to the first distal tip 18a, and a second end 22b that is attached at or proximal to the second distal tip 18b (refer to Figure 4A).

[0058] A method according to an embodiment includes placing a catheter in a vessel having a lesion, the catheter including a first elongate flexible tube having a first lumen and including a first distal tip, a second elongate flexible tube, having a working lumen and including a second distal tip, positioned coaxially within and lying generally coextensively with the first elongate flexible tube, the second elongate flexible tube extending a distance past the first elongate flexible tube, the first and second elongate flexible tubes being coupled together proximate the first and second distal tips by an extended polytetrafluoroethylene (ePTFE) segment.

[0059] According to a particularly advantageous embodiment, the method includes occluding the vessel by crumpling the ePTFE segment in connection with moving the first elongate flexible tube at least partially over the second elongate flexible tube, proximate to the lesion.

[0060] According to an alternative embodiment, the method includes providing digital access through the vessel by an insertion of the first elongate flexible tube therein. The method optionally includes injecting a liquid embolic through a lumen selected from the group consisting of the working lumen and the first lumen.

[0061] Similar to Figures 4A and 4B, Figures 6A and 6B illustrate side views of the catheter 10. As indicated in the drawings and as previously discussed throughout this disclosure, the catheter 10 may include a first elongate flexible tube 12a, a second elongate flexible tube 12b, and an ePTFE segment 20. As depicted, the first distal tip 18a of the first elongate flexible tube 12a is bonded (or otherwise coupled) to the ePTFE segment 20 at or adjacent to the first end 22a of the ePTFE segment 20. The second distal tip 18b of the second elongate flexible tube 12b is configured to extend from the ePTFE segment 20 to at or adjacent to the second end 22b of the ePTFE segment 20 for bonded connection thereto. Accordingly, the ePTFE segment is configured to move (e.g., slide) along the second elongate flexible tube 12b while remaining coupled to both the first elongate flexible tube 12a (at the first distal tip 18a) and to the second elongate flexible tube 12b (at a point proximal the second distal tip 18b).

[0062] Advantageously, the ePTFE segment is fixedly coupled to the first elongate flexible tube 12a and the second elongate flexible tube 12b at the points previously mentioned.

[0063] Figure 6A illustrates the ePTFE segment 20 in an expanded state 800, also referred to as an extended position. Figure 6B illustrates the ePTFE segment 20 in a compressed state 802, also referred to as an at least partially crumpled position. As previously discussed, movement of the first elongate flexible tube 12a in a distal direction may cause a crumpling or similar folded or corrugated compression of the ePTFE segment 20, thereby effectively occluding a vessel 28 (not shown in Figures 6A and 6B). Figure 6B illustrates a shorter length of ePTFE segment 20 compared to Figure 6A and indicates some folding of the ePTFE segment 20, illustrating the overall compression of the ePTFE segment 20 to create a crumple zone within a vessel 28.

[0064] Figures 7A-7C illustrate perspective views of the catheter 10, and show how, in accordance with a particulary advantageous embodiment, the second elongate flexible tube 12b weaves through the ePTFE segment 20, serving to create flex points for folding into the crumple zone. For example, as indicated in Figure 7A, the second elongate flexible tube 12b may extend through the ePTFE segment 20 to an unseen back side (if the ePTFE segment 20 is considered similar to a sheet), extend back through to the front and then back to the back side (demonstrated by the middle visible portion of the second elongate flexible tube 12b), and finally extend back to the front one final time before extending distal to the ePTFE segment 20. It should also be noted that similar to Figure 6A, Figure 7 A shows the ePTFE segment 20 in an expanded state 900. In the expanded state 900 (or extended, generally flatted position), the ePTFE segment 20 is configured to not occlude fluid flow through a vessel 28. This concept will be discussed further with reference to Figures 8A-8C.

[0065] Figure 7B illustrates the ePTFE segment 20 in a partially compressed state 902, depicted as being between the expanded state 900 and the compressed state 904 of Figure 7C. In the partially compressed state 902, the first elongate flexible tube 12a has been partially advanced in a distal direction, though not enough to fully compress to form a crumple zone in the ePTFE segment 20. The advancement of the first elongate flexible tube 12a is illustrated in Figure 7B by showing a gap between the proximal ends of the first elongate flexible tube 12a and the second elongate flexible tube 12b. Comparatively, Figure 7A shows that in the expanded state 900, the proximal ends of the elongate flexible tubes 12a, 12b maybe located adjacent to one another. Figure 7B also illustrates that partial compression of the ePTFE segment 20 may begin to obscure the middle segment of the second elongate flexible tube 12b, whichis shown with a reduced length in Figure 7B compared to Figure 7A.

[0066] Figure 7C illustrates the ePTFE segment 20 in a compressed state 904. As previously discussed, the compressed state 904 (crumpled position) may be configured to occlude fluid flow through a blood vessel 28 during a number of medical procedures. The compressed state 904 may also result in substantially completely obscuring the middle segment of the second elongate flexible tube 12b, as illustrated in Figure 7C. Figure 7C also shows increased distal movement of the first elongate flexible tube 12a compared to Figures 7A and 7B. Referring now to Figures 8A-8C, the drawings are similar to those of Figures 7A-7C with the addition of block arrows to indicate fluid flow. As mentioned with reference to Figure 7A, in the expanded state 900 (extended position), the ePTFE segment 20 may be configured to not occlude fluid flow through a vessel 28. As indicated by the block arrows of Figure 8A, full flow 1000 may be achieved around the ePTFE segment 20 when the ePTFE segment 20 is extended or expanded.

[0067] In comparison, Figure 8B shows the ePTFE segment 20 in a configuration corresponding to the partially compressed state 902 shown in Figure 7B. Accordingly, some fluid flow is possible around the ePTFE segment 20 in the partially compressed state 902. However, the result is a reduced flow 1002 compared to the full flow 1000 illustrated in Figure 8 A.

[0068] Further compression of the ePTFE segment 20, as indicated in Figure 8C (showing the compressed state 904 of Figure 7C), may result in an occluded flow 1004. As indicated in Figure 8C, fluid is able to flow from a proximal direction to the ePTFE segment 20, but is prevented from passing the ePTFE segment 20 and continuing to flow in a distal direction

[0069] Once occluded flow 1004 is achieved, the procedure may include injection of an embolic agent 1100, as shown in Figure 9. Injection of the embolic agent 1100 was discussed previously in this disclosure, particularly with reference to Figure 7. In some embodiments, the embolic agent 1100 comprises glue or a copolymer such as ONYX ™ to permanently occlude a vessel 28, such as, for example, treatment of an AVM. Following injection of the embolic agent 1100, the first elongate flexible tube 12a may be retracted to extend the ePTFE segment 20, facilitating removal of the whole catheter 10. It should be noted that the catheter 10 maybe configured to inject other types of embolic agents 1100 than the few examples listed here, and that the catheter 10 maybe used for a number of different procedures, including those not specifically discussed in this disclosure. Turning now to Figures 1 OA and 1 OB, top views of the catheter 10 in a vessel 28 are shown. Similar to Figures 3A, 4A, 8A, and 7A, Figure 10A shows the ePTFE segment 20 in an expanded state 1200. The top view shows how the ePTFE segment 20 may extend from the first elongate flexible tube 12a, and how the second elongate flexible tube 12b may extend distally to the ePTFE segment 20. It should be noted that for the sake of simplicity of illustrating the catheter 10, Figure 10A, like Figure 6A, shows the ePTFE segment 20 as a simple sheet, visible as just a planar line from a top view. Optionally, the ePTFE segment 20 can assume a more complex shape, as shown in Figures 7A and 8A, and the second elongate flexible tube 12b is configured to weave in and out of the ePTFE segment 20.

[0070] Figure 10B, like Figures 3B, 4B, 6B, and 7C, shows the ePTFE segment 20 in a compressed state 1202 upon distal advancement of the first elongate flexible tube 12a. Though Figure 12B illustrates the ePTFE segment 20 as having a zig-zag shape in the compressed state 1202, the ePTFE segment 20 may be configured to compress, fold, or crumple in any number of orientations, as long as the vessel 28 is sufficiently occluded. For example, the ePTFE segment 20 may fold upon itself, crumple similar to a piece of paper, or any number of other possible compressed configurations.

[0071] Figures 11A and 11B are similar to Figures 10A and 10B, but show the catheter 10 in a vessel 28 from a cross-sectional view, rather than a top view. Figure 11A shows the ePTFE segment 20 in an expanded state 1300, while Figure 11B shows the ePTFE segment 20 in a compressed state 1302. As illustrated in Figure 11B, in the compressed state 1302, the ePTFE segment 20 may be configured to substantially occlude the vessel 28, thereby preventing fluid flow through the vessel. Figures 11 A and 1 IB also show the first elongate flexible tube 12a and the second elongate flexible tube 12b located substantially in the center of the vessel 28. In this regard, it is noted that according to a particularly advantageous embodiment, ePTFE segment 20 (ribbon) is dimensioned wider than an internal diameter (ID) of the vessel being treated, such that when compressed (crumpled), more complete occlusion is achieved by folding of the corners of the ribbon when compressed longitudinally.

[0072] As shown in F igure 11 B , in accordance with the above mentioned particularly advantageous embodiment, ePTFE segment 20 can advantageously be of a selected oversized width relative to an interior diameter of vessel 28, such that when compressed to form the crumple zone, as depicted in Figure 1 IB, corners 20' of the compressed ePTFE segment 20 will create folds which will achieve at least substantial occlusion of vessel 28.

[0073] Turning to Figure 13, an optional delivery housing for maintaining sterility of the catheter prior to insertion in a patient vessel. As depicted, catheter 10 is optionally threaded through a coiled outer protective tubing so as to conveniently maintain sterility until use.

[0074] It should be noted that successful use of the catheter 10 may not require perfect centering of the first and second elongate flexible tubes 12a, 12b. Collapsable ribbon could be used to partially or completely impede the flow of blood within vasculature throughout the body

[0075] It is further noted that an alternative application for the disclosed collapsible ribbon (eg., ePTFE segment 20) includes partially or completely impeding the flow of blood, and would optionally be applied to stroke events to create flow arrest in a manner similar to existing Balloon guide catheters. In this regard, the alternative application would be to temporarily occlude to partially or completely impede the flow of blood in a vessel in order to allow a perforation (hole in vessel wall causing bleeding) or a damaged vessel, to heal or stop bleeding. The vessel would be, for example, temporarily occluded for 1 second or less to 60 minutes or more in order to allow the vessel to heal, after which point the collapsed device ribbon would be expanded to allow flow to resume, and the catheter along with the ribbon removed from the body of the patient.

[0076] Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention.

[0077] It is to be noted that none of the methodology described herein is essential or indispensable. Any of the described approaches can be adjusted or modified without departure from the invention. Other or additional steps can similarly be employed. Any portion of any of the steps, processes, structures, and / or devices disclosed or illustrated in one embodiment, flowchart, or example in this specification can be combined or used with or instead of any other portion of any of the steps, processes, structures, and / or devices disclosed or illustrated in a different embodiment, flowchart, or example. The embodiments and examples provided herein are not intended to be discrete and separate from each other.

[0078] The various features and processes described above may be used independently of one another or may be combined in various ways. All possible combinations and subcombinations are intended to fall within the scope of this disclosure. In addition, certain method, event, state, or process blocks may be omitted in some implementations. The methods, steps, and processes described herein are also not limited to any particular sequence, and the blocks, steps, or states relating thereto can be performed in other sequences that are appropriate. For example, described tasks or events maybe performed in an order other than the order specifically disclosed. Multiple steps maybe combined in a single block or state. The example tasks or events may be performed in serial, parallel, or some other manner. Tasks or events may be added to or removed from the disclosed example embodiments. The example systems and components described herein may be configured differently than described. For example, elements may be added to, removed from, or rearranged compared to the disclosed example embodiments.

[0079] Although specific embodiments and examples have been disclosed herein, it is contemplated that inventive subject matter extends beyond the specifically disclosed embodiments to other alternative embodiments and / or uses, and to modifications and equivalents thereof. Thus, the scope of the claims appended hereto is not limited by any of the particular embodiments described herein. For example, in any method or process disclosed herein, the acts or operations of the method or process may be performed in any suitable sequence and are not necessarily limited to any particular disclosed sequence. Various operations may be described as multiple discrete operations in turn, in a manner that maybe helpful in understanding certain embodiments. However, the order of description should not be construed to imply that these operations are order-dependent. Additionally, the structures, systems, and / or devices described herein may be embodied as integrated components or as separate components.

[0080] For purposes of comparing various disclosed embodiments, certain aspects and advantages of these embodiments are described. Not necessarily all such aspects or advantages are achieved by any particular embodiment. Thus, for example, various embodiments may be carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other aspects or advantages as may also be taught or suggested herein.

Claims

What is claimed is:

1. A catheter, comprising: a first elongate flexible tube having a first distal portion and a non-stick chemistry segment disposed at the first distal portion; and a second elongate flexible tube disposed at least partially within the first elongate flexible tube and having a second distal portion, the second elongate flexible tube having a working lumen for delivery of a liquid embolic, the first elongate flexible tube and the second elongate flexible tube being slidable with respect to each other such that sliding the first elongate flexible tube distally with respect to the second elongate flexible tube causes the nonstick chemistry segment to at least partially crumple and expand outwardly to block a blood vessel and prevent proximal backflow of the liquid embolic.

2. A catheter according to claim 1, wherein the non-stick chemistry segment is configured as a flexible ribbon having a proximal end and a distal end opposite the proximal end.

3. A catheter according to claim 2, wherein the first distal portion of the first elongate flexible tube is coupled to the proximal end of the flexible ribbon.

4. A catheter according to claim 3, wherein the second elongate flexible tube extends through at least one opening in the flexible ribbon and the second distal portion of the second elongate flexible tube is coupled to the distal end of the flexible ribbon.

5. A catheter according to claim 4, wherein the flexible ribbon comprises a nonstick chemistry selected from the group consisting of a non-stick chemistry coating, a non-stick chemistry material, and combinations thereof.

6. A catheter according to claim 5, wherein the non-stick chemistry comprises ePTFE.

7. A catheter according to claim 1, wherein the non-stick chemistry segment defines a portion disposed at least partially around the first distal portion.

8. A catheter according to claim 1, wherein the non-stick chemistry segment includes ePTFE.

9. A catheter according to claim 1, wherein the non-stick chemistry segment includes a hydrophilic coating.

10. A catheter according to claim 1 , wherein the first distal portion and the second distal portion are each coated with a hydrophilic coating.

11. A method of treating a vessel, comprising: placing a catheter in the vessel, the catheter including: a first elongate flexible tube having a first distal portion and a non-stick chemistry segment disposed at the first distal portion; and a second elongate flexible tube disposed at least partially within the first elongate flexible tube and having a second distal portion, the first elongate flexible tube and the second elongate flexible tube being slidable with respect to each other; moving the first elongate flexible tube distally with respect to the second elongate flexible tube; at least partially occluding the vessel in response to moving the first elongate flexible tube distally with respect to the second elongate flexible tube.

12. A method according to claim 11, further comprising:providing said second elongate flexible tube with a working lumen for delivery of a liquid embolic; and injecting a liquid embolic through a lumen selected from the group consisting of a first elongate flexible tube lumen, the working lumen, and combinations thereof13. A method according to claim 11, wherein the first elongate flexible tube and the second elongate flexible tube define a first direction, wherein: the occluding the vessel further comprises collapsing the non-stick chemistry segment along the first direction, and the non-stick chemistry segment expands radially along a second direction that is substantially perpendicular to the first direction in response to collapsing the non-stick chemistry segment along the first direction.

14. A method according to claim 11, further comprising: moving the first elongate flexible tube proximally with respect to the second elongate flexible tube; and causing blood to flow through the vessel in response to moving the first elongate flexible tube distally with respect to the second elongate flexible tube, wherein: the causing blood to flow through the vessel includes expanding the nonstick chemistry segment along the first direction, and the non-stick chemistry segment collapses radially along the second direction in response to expanding the non-stick chemistry segment along the first direction.

15. A method according to claim 11, wherein the non-stick chemistry segment is configured as including a flexible ribbon having a proximal end and a distal end opposite the proximal end.

16. A method according to claim 13, wherein the first distal portion of the first elongate flexible tube is coupled to the proximal end of the flexible ribbon.

17. A method according to claim 14, wherein the second elongate flexible tube extends through at least one opening in the flexible ribbon and the second distal portion of the second elongate flexible tube is coupled to the distal end of the flexible ribbon.

18. A method of according to 15, wherein the non-stick chemistry segment comprises a non-stick chemistry selected from the group consisting of a non-stick chemistry coating, a non-stick chemistry material, and combinations thereof.

19. A method according to claim 11, wherein the non-stick chemistry segment defines a portion disposed at least partially around the first distal portion.

20. A catheter, comprising: a first elongate flexible tube having a first distal portion; and a second elongate flexible tube disposed at least partially within the first elongate flexible tube and having a second distal portion, the first elongate flexible tube and the second elongate flexible tube being slidable with respect to each other; and a non-stick chemistry segment in a general form of flexible ribbon having a proximal end and a distal end opposite the proximal end, the first distal portion of the first elongate flexible tube being coupled to the proximal end of the flexible ribbon, and the second distal portion of the second elongate flexible tube being coupled to the distal end of the flexible ribbon, such that sliding the first elongate flexible tube distally with respect to the second elongate flexible tube causes the non-stick chemistry segment to at least partially crumple and expand outwardly to at least partially block a vessel within which the catheter is received.

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