HK1245614A1 - Perfusion catheters and related methods - Google Patents

Abstract

This patent document discloses perfusion catheters and related methods for treating complications related to CTO interventions or dilating a vessel occlusion while maintaining a passage through the treated vessel segment. A perfusion catheter can include a balloon formed of an inflatable tube and an elongate shaft having a lumen for providing inflation fluid to, or withdrawing inflation fluid from, the balloon. The inflatable tube can be coiled in a helical manner around a central axis into a series of windings. Adjacent windings can be stacked against and bonded to each other, and an inner surface of the series of windings, when inflated, can define the passage. The elongate shaft can be eccentrically attached to a proximal portion of the balloon and the shaft's lumen can be in fluid communication with the interior of the balloon, specifically the inflatable tube. The inflatable tube can include two different polymer tubes, one slightly smaller than the other.

Description

Perfusion catheter and related methods

This application is a divisional application of the invention application having a filing date of 10/09/2015, application number 201580060554.3, entitled "perfusion catheter and related methods".

Priority requirement

The priority rights of the following applications are hereby claimed: united states provisional patent application serial No. 62/048,726 entitled "perfusion catheter" filed 9/10 2014; U.S. provisional patent application serial No. 62/078,240 entitled "perfusion catheter and associated methods," filed 11/2014, each of which is incorporated herein by reference in its entirety.

Technical Field

This patent document relates to medical devices. More particularly, but not by way of limitation, this patent document relates to catheters and related methods for closing vessel perforations or dissecting or dilating vessel occlusions.

Background

Severe or Chronic Total Occlusion (CTO) is a vascular obstruction that prevents blood flow through the occlusion. Chronic total occlusions occur most frequently in coronary and peripheral arteries and are caused by atherosclerosis.

The procedure for treating CTO is percutaneous transluminal angioplasty. During angioplasty, access to the desired vessel is obtained and a guidewire is introduced into the vessel. The guidewire is maneuvered into position, including into and through the occlusion, and is used as a guide to position a subsequent treatment device for dilating or otherwise treating the vascular occlusion. The treatment device can be advanced over the guidewire so that its distal portion is within the occlusion. The inflatable balloon at the distal portion of the treatment device may then be inflated to apply radial pressure to the occluding substance and adjacent portions of the inner wall of the vessel, thereby clearing the occlusion for better blood flow.

Summary of The Invention

The present inventors have recognized that CTO creates an occlusive structure and, as such, it is one of the most challenging lesion types in the treatment of interventional cardiology. Complications associated with CTO interventions include vessel wall perforation and dissection. Bleeding from the blood vessel by this puncture or dissection can lead to death of the patient within minutes if not treated in time.

The present inventors have further recognized that sealing a vascular puncture or dissection using a conventional balloon catheter, completely interrupts blood flow within the injured vessel upon inflation of the balloon of the catheter. Inflating the balloon for a prolonged period of time may risk damaging the part of the body that the blood vessel nourishes-the part is already weakened due to insufficient blood supply. For example, to effectively treat a puncture, dilations up to several minutes may need to be employed. However, most adults can only tolerate 30-60 seconds of non-perfused dilatation without significant side effects.

The perfusion catheter of the present invention can be quickly and easily deployed in a damaged vessel and, after its balloon is inflated, can form and provide a channel (or flow lumen). The perfusion catheter may include a balloon formed of an inflatable tube and an elongate shaft having a lumen for providing inflation fluid to or withdrawing inflation fluid from the balloon. The expandable tubular may be wound in a helical fashion into a series of windings about a central axis. Adjacent windings may be stacked upon and bonded to each other, and when expanded, the inner surface of the series of windings may define the channel. The elongate shaft may be eccentrically attached to the proximal portion of the balloon, and its lumen may be in fluid communication with the interior of the inflatable tube. The expandable tube may comprise two different polymeric tubes, one of which is slightly smaller than the other. The smaller inner tube may be formed of a polymer having sufficient radial stiffness to resist collapsing or rupturing when exposed to expansion pressure, and the larger outer tube may be formed of a polymer configured to exhibit adhesive properties when heated.

Existing methods for closing a puncture or stripping or dilating an occlusive material may include inserting a guidewire into a blood vessel and advancing the guidewire to or through a treatment site, passing an infusion catheter over the guidewire until a distal portion of the infusion catheter is positioned near or within the treatment site, and inflating a balloon of the infusion catheter. Inflating the balloon may include inflating a series of contact windings of the helically wound tube. The balloon may be changed from a deflated configuration to an inflated configuration upon inflation, in which case the outer surface of the balloon may engage the wall of the vessel and the inner surface of the balloon may define the passageway. The channel may allow bodily fluids, such as blood, to flow through the perfusion catheter. Optionally, the method may comprise passing the treatment device at least partially through the passageway.

The objects of the perfusion catheter and associated method of the present invention include, inter alia, the following:

1. sealing a vessel puncture or dissection by blocking an injury within the vessel for an extended period of time while maintaining sufficient blood flow through the treated vessel segment;

2. dilating the vascular occlusion for an extended period of time while maintaining adequate blood flow through the treated blood vessel segment; and/or

3. Delivering or receiving one or more therapeutic devices while sealing vessel perforations or dissecting or dilating vessel occlusions.

These and other examples of the perfusion catheter and associated methods of the present invention and its purposes are set forth in the detailed description of the invention which follows. This summary is intended to provide non-limiting examples of the present subject matter-it is not intended to provide an exclusive or exhaustive explanation. The following detailed description is included to provide further information regarding the perfusion catheters and related methods of the present invention.

Drawings

In the drawings, like reference numerals may be used to describe similar features and components in the several views. The drawings illustrate generally, by way of example, but not by way of limitation, embodiments discussed in this patent document.

Fig. 1 shows a schematic view of an end cap (endcap) with a guidewire advanced through a patient's vasculature, but failed to penetrate an occlusion within a vessel.

Fig. 2 shows a schematic view of the distal portion of the treatment device at the occlusion within the vessel segment expanded (such expansion causing dissection of the vessel wall).

FIG. 3 illustrates a side view of an irrigation catheter as constructed in accordance with at least one embodiment.

Fig. 4 shows an enlarged side view of the distal portion of the perfusion catheter shown in fig. 3 with the balloon in a deflated configuration within the vessel segment.

Fig. 5 shows an enlarged side view of the distal portion of the perfusion catheter shown in fig. 3 with the balloon in a deflated configuration within the vessel segment.

Fig. 6 illustrates an enlarged side view of a distal portion of an infusion catheter containing a dedicated guidewire lumen as constructed in accordance with at least one embodiment.

FIG. 7 illustrates a side view of a squeeze tube member (tubing) in a balloon for an infusion catheter, as constructed in accordance with at least one embodiment.

Fig. 8 shows a cross-sectional view of the extruded tubing piece shown in fig. 7.

Fig. 9 illustrates a mandrel for manufacturing a balloon of an infusion catheter as constructed in accordance with at least one embodiment.

FIG. 10 illustrates a side view of an elongate shaft of an irrigation catheter as constructed in accordance with at least one embodiment.

FIG. 11 shows a cross-sectional view of the elongate shaft shown in FIG. 10.

Fig. 12 illustrates a method of using an infusion catheter to occlude a vessel puncture or dissection or dilate a vessel occlusion while maintaining a passageway, as constructed in accordance with at least one embodiment.

The drawings are not necessarily to scale. Certain features and components may be shown exaggerated in scale or in somewhat schematic form and some details may not be shown in the interest of clarity and conciseness.

Detailed Description

With advances in medical instrumentation and increased training, clinicians have used angioplasty to treat CTO at any time than ever before. The catheter and method of the present invention provide a means for clinicians to treat complications associated with CTO angioplasty interventions or dilate vascular occlusions while maintaining access through the treated segment of the blood vessel. Although the catheters and methods are discussed primarily in relation to treatment of coronary arteries, they may also be used in other vessels throughout the body, including peripheral arteries and veins.

Figures 1 and 2 provide examples of complications associated with CTO angioplasty interventions, where the perfusion catheter and associated methods of the present invention may be beneficial. Successful treatment of occlusion in CTO patients can be challenging. One factor may determine whether the clinician applying the treatment is able to successfully treat the occlusion, that is, the clinician's ability to advance the guidewire from a first side of the occlusion to a second side of the occlusion. In some cases, for example, when the natural lumen 102 of the blood vessel 104 is completely occluded by a hard plaque 106 (e.g., a calcified atherosclerotic plaque), the guidewire 108 cannot pass through the occlusion, and its distal portion 112 may deflect away from and perforate 114 an adjacent blood vessel wall 116 in response to the continued proximally applied pushing force 110, as shown in fig. 1.

In other cases, such as when the occluding material 206 is soft or has a slight opening at the occlusion, the guidewire 208 may be pushed through the occluding material and allowed to reside within the natural lumen 202 of the blood vessel 204. A treatment device, such as a balloon catheter 218, may be guided over the guidewire 208 to the occlusion site where it may be used to perform dilation treatment. Mechanical expansion of the blood vessel 204 with the balloon catheter 218 may be associated with plaque rupture, intimal wall disruption, and local medial dissection. The dissection 220, if it occurs, may diffuse into the media and through the adventitia (the outermost layer of the vessel wall), resulting in another form of coronary perforation, as shown in figure 2.

The associated morbidity and mortality of perforation and exfoliation makes it a serious complication in catheterization laboratories, for which only its management and treatment is important and should be initiated quickly. The first step in the management and treatment may be the placement of a balloon to close the puncture or dissection. Prolonged balloon inflation may successfully seal the puncture or prevent the propagation of the peel, and may provide time for preparation and implantation of the stent graft, if desired.

The perfusion catheter 300 of the present invention may be used in the presence of a puncture or dissection of a blood vessel to be treated, and also in the presence of an occlusive material to be dilated. The catheter 300 may be advanced through a guide catheter and guided through the vasculature to treat vessel wall damage using a guidewire and, optionally, placement of the catheter. The perfusion catheter 300 may include a proximal manifold 324 for coupling to an inflation syringe, an elongate shaft 326, and a distal balloon 328 to close the perforation or to strip or dilate occlusive material.

The elongate shaft 326 may serve two primary purposes. First, the elongate shaft 326 can transmit force applied by a clinician during an angioplasty or closure procedure to advance or retract the perfusion catheter 300, and in particular the balloon 328. By manipulating the elongate shaft 326, the balloon 328 may be inserted through a guide catheter and out the distal portion of the guide catheter into a puncture or dissection to be sealed or an occlusion to be dilated. Next, the elongate shaft 326 includes a lumen 330 for providing inflation fluid to the balloon 328 or withdrawing inflation fluid from the balloon 328. The lumen 330 of the elongate shaft 326 can be in fluid communication with the manifold 324, can be coupled to an inflation syringe at a proximal portion 332 thereof, and the lumen 330 can be in fluid communication with the interior of the balloon 328 near a distal portion 334 thereof.

The elongate shaft 326 may be eccentrically attached to the proximal portion 336 of the balloon 328 and may extend proximally to access a clinician positioned outside of the guide catheter. The elongate shaft 326 may be attached to the balloon 328 by wrapping and securing the balloon 328 around a middle portion 338 or a distal end 334 portion of the shaft. In an example, the elongate shaft 326 is attached to the proximal portion 336 of the balloon 328 by at least 5 mm.

The embodiment of fig. 3 shows that the balloon 328 may be formed from an expandable tube 340 wound in a spiral or helical fashion into a series of windings 342 (or rings) around a central axis, wherein successive or adjacent windings 342 are stacked upon one another and in contact with one another with substantially no gaps therebetween. This may ensure that the winding 342 acts as one component. The inner surface of the windings 342 may define a channel 344 through the open center of the spiral when the spiral balloon 328 is inflated. The channel 344 may extend along the entire length of the balloon 328 to allow blood or other fluids to perfuse (or flow through) therein, which is important because prolonged cutting off of the blood supply is undesirable. When deflated, the balloon 328 may collapse or flatten into a low-profile configuration, which may include one or more folds wrapped around the distal end portion 334 of the elongate shaft 326. An elastic sheath may optionally be disposed around the balloon 328 and may be used to reduce the collapse profile of the deflated balloon so that it may be more easily inserted into or removed from the patient.

Because the balloon 328 creates the channel 344, blood flow is allowed through the channel 344 and the entire perfusion catheter 300 can be kept at a minimum size. This physical property allows the catheter 300 to have a small diameter when it is inserted into a patient's body and maneuvered to a desired location, while the catheter 300 provides a relatively large blood flow channel when the balloon 328 is inflated.

Fig. 4 shows a perfusion catheter 400 in a blood vessel 404 of a patient. The catheter 400, and in particular the balloon 428 of the catheter, may be introduced and advanced into the vessel 404 in a low profile, unstretched configuration. In this configuration, the balloon 428 is in a relaxed, folded or collapsed configuration and does not significantly increase the overall diameter of the distal portion of the catheter 400 so that it can be inserted into a patient and navigated through the patient's vasculature to a desired treatment site.

Once at the treatment site, balloon 528 may be inflated as shown in fig. 5. Fluid may be provided under pressure to the balloon 528 through the inflation lumen 530 of the elongate shaft 526, thereby stretching the balloon 528 toward the wall 516 of the blood vessel 504 to, for example, close, open, or otherwise treat. When inflated, the balloon 528 may be in intimate contact with or engage the vessel wall 516 at the treatment site, e.g., at a pressure of 2atm to 20atm, but blood may be allowed to flow through the channels 544 defined by the windings 542 of the balloon. Since the channel 544 created by the windings 542 is relatively large compared to the size of the blood vessel 504, disruption of blood flow through the blood vessel is minimized and the perfusion catheter 500 can be inflated for a longer period of time to temporarily stop bleeding in a coronary puncture or dissection.

In addition to allowing fluid flow, the channel 544 of the balloon 528 can be adapted to slidably receive a therapeutic device (e.g., a smaller diameter balloon catheter, stent catheter, guidewire support catheter, or guidewire). The balloon 528 may contain any number of windings 542 in a variety of sizes and configurations depending on the particular treatment site, procedure, and/or patient. Increasing the number of windings 542 in the balloon 528 can increase the ability of the balloon 528 to maintain an expanded state of the occlusion. For example, the channel 544 may have a diameter 546 in the range of 2mm-6mm and a length 548 that may extend in the range of 10mm-50 mm. The diameter 546 of the channel 544 can be large enough to allow entry of a stent catheter. The inventors of the present invention have recognized that plaque has a tendency to recover its original form and restrict the passage. This restenosis, if it occurs, can be performed rapidly within minutes. The perfusion catheter 500 allows the stent catheter to be delivered through the catheter while the balloon 528 expands the occlusion. In this manner, time during occlusion expansion and stent placement may be minimized. The diameter 546 of the channel 544 can be large enough to accommodate a guidewire support catheter to help pre-expand or otherwise establish a guide opening through the occlusion; or a distal portion of a retrograde guidewire, the engagement between the outer surface 550 of the balloon 528 and the vessel wall 516 causing the distal portion to be introduced into the channel 544.

When the procedure is complete, the balloon 528 can be deflated by applying a vacuum to a proximal manifold coupled to the inflation lumen 530 of the elongate shaft 526. The entire irrigation catheter 500 may then be removed.

Fig. 6 illustrates an enlarged side view of a distal portion of an irrigation catheter 600 constructed in accordance with at least one embodiment. The catheter 600 may be provided with a guidewire lumen 652 separate from the channel 644 defined by the windings 642 of the balloon 628 and separate from the lumen 630 of the elongate shaft 626 for providing inflation fluid to or withdrawing inflation fluid from the balloon 628. The guidewire lumen 652 may have a length 654 that is approximately equal to or slightly longer than the length 648 of the channel 644 and may be positioned therein. The outer surface of the guidewire support tube 656 forming the guidewire lumen 652 can contact the inner surfaces of the windings 642 of the balloon 628, and can optionally be inserted into these inner surfaces. The polymers of the guidewire support tube 656 and the balloon 628 can be configured to adhere to one another after the heat treatment is applied.

The guidewire lumen 652 is designed to receive and facilitate tracking of a previously positioned guidewire having a distal portion positioned proximate to or across the treatment site. The infusion catheter 600, and in particular the guide wire support tube 656, can be slid over the guide wire and advanced to the treatment site. The inner diameter of the guidewire support tube 656 may be sized to be advanced over, for example, a 0.36mm (0.014 inch) guidewire. An atraumatic tip 658 may be provided at the distal end of the guidewire support tube 656 to prevent the perfusion catheter 600 from causing vessel perforation during deployment and use. Since the guide wire support tube 656 may be short compared to the total length of the catheter 600 and the guide wire, using the guide wire support tube 656 as a guide allows for rapid exchange of the catheter 600 over the guide wire.

One or more radiopaque markers 660 may be placed on the guidewire support tube 656 or the elongate shaft 626, proximal or distal to the balloon 628. The markers 660 may facilitate proper placement of the balloon 628 relative to the vessel wall lesion prior to inflation thereof, and may be any suitable radiopaque material detectable by using x-ray or fluoroscopy. Materials such as platinum group metals (e.g., platinum or palladium), gold, silver, iridium, or tantalum may be used as the marker. Certain stainless steels may also be suitable for use as markers. Alternatively, the polymer used in a portion of the perfusion catheter 600 may be radiopaque; or made radiopaque by the addition of fillers such as barium sulfate, bismuth trioxide, bismuth carbonate, tungsten, tantalum, and the like.

Fig. 7 and 8 illustrate side and cross-sectional views, respectively, of an extruded tube 740 in a balloon for a perfusion catheter, constructed in accordance with at least one embodiment. The extruded tubing member 740 may have a uniform outer diameter along its length 762 or may have a larger diameter along a substantial portion of its length and taper over portions of its proximal end 764 and distal end 766. The distal portion 766 of the extruded tubing piece 740 may be closed by crimping the tubing piece and/or plugging the tubing piece with a thermoplastic filler or the like. The extruded tubing 740 may have a length 762 ranging from 40cm to 120cm before being wound into a series of windings in a helical or spiral manner.

The wound shape of the balloon may be maintained by adhering adjacent windings to each other, and a complete balloon may be provided inside each winding. These qualities can be accomplished by co-extruding a combination of nested polymers that can be heat treated after coil winding to allow adjacent coils to adhere to each other. In the example of FIG. 8, the extruded tubing 840 is formed by co-extruding two different polymer tubes 868, 870 (or layers; one slightly smaller than the other). The co-extrusion process may eliminate seams found in existing balloon designs, form a tight joint, and use a smaller number of manufacturing steps to manufacture the balloon. Alternatively, the smaller tube 868 may be inserted into the larger tube 870 after extrusion.

The smaller inner tube 868 may be formed of a polymer having sufficient radial stiffness to resist collapsing or rupturing when exposed to expansion pressure, and the larger outer tube 870 may be formed of a polymer configured to exhibit adhesive properties when heated and compliant properties when used within the body. The adhesive properties of the outer tube 870 may allow adjacent windings to adhere to each other. The use of a compliant material for the outer tube 870 may enable the balloon to conform to the vessel wall at the puncture or tear site or at the occlusion site that may benefit from expansion, such that a majority of the outer surface of the balloon may be pressed against the vessel wall. In various examples, the inner tube 868 can comprise polyethylene terephthalate (PET) having an outer diameter of 0.2mm to 0.28mm and an inner diameter of 0.12mm to 0.18mm orPolyether block amide (available from Arkema), and the outer tube 870 may comprise an outer diameter of 0.28mm to 0.36mm and an inner diameter of 0.20mm to 0.28mmPolyester elastomers (available from e.i. du Pont de Nemours and Company), Pebax or nylon. The inner tube 868 and the outer tube 870 may comprise polymers having different melting or softening temperatures, wherein the inner tube 868 comprises a polymer having a higher melting temperature. The inner tube 868 andthe outer tube 870 may comprise the same or similar polymers, wherein the polymer of the inner tube 868 is crosslinked to achieve strength, while the polymer of the outer tube 870 is not crosslinked.

Fig. 9 shows a mandrel 972 for winding an extruded tubing around a central shaft in a helical fashion into a series of windings to form a balloon. The extruded tube may be wrapped in a distal direction around the mandrel 972, which contains the shape of the desired profile of the balloon. After winding onto the mandrel 972, the extruded tube may be pressurized or expanded and the adjacent windings may be heat set to ensure that they adhere to each other and the balloon retains its wound shape. For example, heat setting the wound configuration of the balloon may include bonding the outer surfaces of adjacent windings of the tube to one another by heating the extruded tube or the mandrel 972. The extruded tubing was then cooled to room temperature.

Fig. 10 and 11 illustrate side and cross-sectional views, respectively, of an elongate shaft 1026, 1126 of an irrigation catheter constructed in accordance with at least one embodiment. The elongate shafts 1026, 1126 may include a lumen 1130 extending from the proximal portion 1032 to an inflation port to provide inflation fluid to the distal balloon or to withdraw inflation fluid from the distal balloon. The elongate shaft 1026, 1126 may extend a length 1074 of 100cm-180cm and may have a compressively rigid mass along its longitudinal axis that facilitates advancement of the perfusion catheter through the patient's vasculature; and has good distal flexibility which enhances the maneuverability of the catheter through directional changes in the vascular system and prevents damage to the vessel wall during insertion. Portions of the elongate shafts 1026, 1126 may include a PTFE coating 1076 to facilitate advancement thereof through the patient's vasculature.

These qualities can be achieved in various ways. In one example, the proximal portion 1032 and the intermediate portion 1038 of the elongate shafts 1026, 1126 may comprise stainless steel hypotubes 1077, 1177, and the distal portion 1034 may comprise a stainless steel support wire 1079, 1179 or tube connected to the intermediate portion by a length 1075. The support wires 1079, 1179 may help to transmit forces applied by a treating clinician to advance or retract the balloon during a treatment procedure. The support wire 1079, 1179 may have a length in the range of 10cm to 20cm and may be secured to the hypotube 1077, 1177 by laser welding. The support wires 1079, 1179 may extend to a location distal to the balloon or may terminate between proximal and distal portions of the balloon. In another embodiment, the elongate shaft 1026, 1126 can be formed from a single piece of metal or polymeric tubing having proximal portions with outer and inner diameters that are larger than the outer and inner diameters of the distal portions; or the wall thickness of the proximal portion is greater than the wall thickness of the distal portion.

The means for securing the outer surface 1078 of the elongate shaft 1026, 1126 and the flexible material of the balloon may be used to withstand the stresses associated with pressure changes of the inflation and deflation of the balloon. It is important that the fixture form a fluid-tight closure between the two materials and limit any delamination along the closure line under prolonged working pressure. In one example, the portion of the elongate shaft 1026, 1126 coupled to the balloon can be covered with nylon (e.g., Vestamid L2101) as part of a fixation device. These materials may be attached by an adhesive process (e.g., cyanoacrylate, epoxy, or urethane compounds); or by a heat treatment or press-fit process that melts or welds the two materials together.

Fig. 12 illustrates a method 1280 of using a perfusion catheter in a coronary vessel to seal a puncture or to strip or dilate an occlusive material while maintaining a passageway.

At 1282, a guidewire may be introduced into the blood system near the groin of the patient and advanced along the aorta to the selected coronary vessel for treatment with the aid of a previously placed guide catheter. The guidewire may then be advanced to or through a treatment site requiring occlusion or dilation. At 1284, optionally, with the aid of a partially expanded placement catheter and a fully collapsed perfusion catheter, the catheter assembly may be passed over the guidewire and advanced until its distal end is near or within the treatment site.

At 1286, the balloon of the perfusion catheter can be expanded from a fully deflated configuration to an expanded configuration by pushing fluid through the elongate shaft. The lumen of the elongate shaft may be in fluid communication with a manifold, may be coupled to an inflation syringe at a proximal portion thereof, and may be in fluid communication with an interior of the balloon near a distal portion thereof. After expansion, the outer surface of the balloon may engage the wall of the coronary vessel (e.g., the wall surrounding the puncture or dissection of the vessel or the accumulation of plaque on the wall) and the inner surface of the balloon may form a channel. The balloon may be inflated up to a pressure, for example in the range of 2-20 atm. These low pressures allow the balloon to be thin-walled, e.g., 0.1-0.5mm, allowing for greater blood flow. In addition, the low inflation pressure allows blood flow in the capillaries at the treatment site. The placement catheter, if used, may now be proximally retracted and retracted, allowing blood flow from the proximal arterial segment to perfuse through the passageway into the oxygenated myocardial tissue distal to the balloon and treatment site.

In 1288, a treatment device can optionally be passed at least partially through the guide catheter and the perfusion catheter. During the passing, the treatment device may be advanced along the elongate shaft, through the channel of the perfusion catheter, and into the target site of the coronary vessel.

At 1290, when a tack-free, puncture-blocking, or occlusion-dilating procedure has taken sufficient time and it is desired to remove the perfusion catheter from the patient, the deployment catheter may be reinserted into the channel and partially inflated to engage the inner surface of the balloon. The balloon of the perfusion catheter may then be deflated and the catheter assembly may be retracted and removed from the patient. In an alternative embodiment of the perfusion catheter incorporating a separate guidewire lumen, the step of re-advancing the placement catheter may be omitted. When it is desired to remove the perfusion catheter, the clinician may simply deflate the balloon to disengage it from the vessel wall, reducing the profile of the catheter, and then the perfusion catheter containing the deflated balloon may be retracted over the guidewire.

End upThe following words:

despite advances in the treatment of CTO, certain complications still remain. The most feared complications during CTO surgery are two, which are coronary perforation or dissection. The perfusion catheter and associated method of the present invention may be used in the presence of a puncture or dissection of a blood vessel to be treated, as well as in the presence of an occlusive material to be dilated. The catheter and method provide several advantages over prior devices and techniques. First, the large diameter of the catheter channel of the present invention can allow for a relatively high blood flow rate when the balloon is inflated. This allows the balloon to be inflated within the vessel for a long time to treat the puncture or dissection without obstructing blood flow. Second, because the channel can be aligned with the main flow axis of the vessel, there is less trauma to the blood and less pressure required for blood flow. Third, the ability to maintain the position of the guidewire while allowing perfusion provides an important option for clinicians.

The above detailed description of the invention includes references to the accompanying drawings, which form a part hereof. The detailed description of the invention should be reviewed with reference to the accompanying drawings. The drawings show, by way of illustration, specific embodiments of catheters and related methods in which the invention may be practiced. These embodiments are also referred to herein as "examples".

The detailed description is intended to be illustrative rather than restrictive. For example, the above-described embodiments (or one or more functional components or assemblies thereof) may be used in combination with each other. For example, one of ordinary skill in the art, after reading the above detailed description, can use other embodiments. In addition, various features or components have been or may be combined together to simplify the disclosure. This is not to be interpreted as an indication that the unclaimed disclosed features are critical to the claims. Rather, inventive subject matter may be found in all features of a particular disclosed embodiment. Thus, the following claimed embodiments are hereby incorporated into the detailed description, with each embodiment standing on its own as a separate implementation:

in example 1, a perfusion catheter may include a balloon and an elongate shaft, the balloon including an inflatable tube and the elongate shaft including a lumen for providing inflation fluid to or withdrawing inflation fluid from the balloon. The expandable tubular may be wound in a helical fashion into a series of windings about a central axis. Adjacent windings may be stacked upon and bonded to each other, and when expanded, the inner surface of the series of windings may define a channel. The elongate shaft may be eccentrically attached to the proximal portion of the balloon, and its lumen may be in fluid communication with the interior of the balloon, in particular with the interior of the inflatable tube.

In example 2, the perfusion catheter of example 1 can optionally be configured such that the inflatable tube comprises two different polymer tubes.

In example 3, the perfusion catheter of example 2 can optionally be configured such that the two different polymer tubes comprise an inner tube and an outer tube. The inner tube is located within the outer tube.

In example 4, the perfusion catheter of example 3 can optionally be configured such that the polymer of the inner tube has a higher melting temperature than the polymer of the outer tube.

In example 5, the perfusion catheter of any one or any combination of examples 3 and 4 can optionally be configured such that the polymer of the inner tube is crosslinked and the polymer of the outer tube is not crosslinked.

In example 6, the perfusion catheter of any one or any combination of examples 2-5 can optionally be configured such that the two different polymer tubes are co-extruded.

In example 7, the perfusion catheter of any one or any combination of examples 1-6 can optionally be configured such that the expandable tube has a length in the range of 40cm-120cm before being helically wound.

In example 8, the irrigation catheter of any one or any combination of examples 1-7 may optionally be configured such that the channel has a diameter in the range of 2mm-6mm and a length in the range of 10mm-50 mm.

In example 9, the perfusion catheter of any one or any combination of examples 1-8 can optionally be configured such that the balloon is wrapped around a portion of the elongate shaft.

In example 10, the perfusion catheter of example 9 can optionally be configured such that the portion of the elongate shaft wrapped around by the balloon is covered with nylon.

In example 11, the perfusion catheter of any one or any combination of examples 9 and 10 can optionally be configured such that the balloon wraps a minimum of 5mm around the elongate shaft.

In example 12, the perfusion catheter of any one or any combination of examples 1-11 can optionally be configured such that the proximal portion and the intermediate portion of the elongate shaft comprise a hypotube.

In example 13, the perfusion catheter of example 12 can optionally be configured such that the distal portion of the elongate shaft comprises a support wire coupled to the intermediate portion.

In example 14, the perfusion catheter of example 13 can optionally be configured such that the support wire extends to a location distal to the balloon.

In example 15, the perfusion catheter of any one or any combination of examples 13 and 14 can optionally be configured such that the support wire extends to a location between the proximal and distal portions of the balloon.

In example 16, the perfusion catheter of any one or any combination of examples 1-15 can optionally further comprise a guidewire lumen.

In example 17, the perfusion catheter of example 16 can optionally be configured such that the guidewire lumen is disposed within the channel.

In example 18, the perfusion catheter of any one or any combination of examples 16 and 17 can optionally be configured such that the guidewire lumen is inserted into the inner surface of the series of windings.

In example 19, the perfusion catheter of any one or any combination of examples 16-18 can optionally be configured such that the guidewire lumen is equal to or slightly longer than the length of the channel.

In example 20, the perfusion catheter of any one or any combination of examples 1-19 can optionally further include a first radiopaque marker proximal to the balloon and a second radiopaque marker distal to the balloon.

In example 21, a method may include inserting a guidewire into a blood vessel and advancing the guidewire to or through a treatment site, passing a perfusion catheter over the guidewire until a distal portion of the perfusion catheter is positioned near or within the treatment site, and inflating a balloon of the perfusion catheter. Inflating the balloon may include inflating a series of contact windings of the helically wound tubular member. The balloon may be changed from a deflated configuration to an inflated configuration upon inflation, in which case the outer surface of the balloon may engage the wall of the vessel and the inner surface of the balloon may define the passageway.

In example 22, the method of example 21 can optionally be configured such that inflating the balloon comprises allowing a flow of body fluid through the channel.

In example 23, the method of example 21 can optionally be configured such that inflating the balloon comprises closing a puncture in the wall of the blood vessel while allowing a flow of bodily fluid through the channel.

In example 24, the method of example 21 can optionally be configured such that inflating the balloon comprises dilating an occluded or narrowed region in the blood vessel.

In example 25, the method of any one or any combination of examples 21-24 can optionally further comprise passing a treatment device at least partially through the passageway.

In example 26, the method of example 25 can optionally be configured such that passing the treatment device at least partially through the passageway comprises receiving a treatment device in a distal-to-proximal direction, the treatment device being introduced into the passageway due to engagement between the outer surface of the inflated balloon and the wall of the blood vessel.

In example 27, the method of example 25 can optionally be configured such that passing the treatment device at least partially through the passageway comprises delivering the treatment device to the treatment site or to a distal end of the treatment site in a proximal to distal direction.

In example 28, the method of any one or any combination of examples 21-27 can optionally further comprise deflating the balloon and retracting the perfusion catheter from the blood vessel.

In example 29, the perfusion catheter or method of any one or any combination of examples 1-28 can optionally be configured such that all of the components or options listed are available for use or selection.

Certain terms are used throughout this patent document to refer to particular features or components. As one skilled in the art will appreciate, different people may refer to the same feature or component by different names. This patent document does not intend to distinguish between components or features that differ in name but not function.

For the following defined terms, specific definitions shall apply unless otherwise defined elsewhere in this patent document. The terms "a" and "an" are used to include one or more, independently of any other instance or use of "at least one" or "one or more". The term "or" is used to indicate nonexclusivity; or "A or B" includes "A but not B", "B but not A", and "A and B". The terms "distal" and "proximal" are used to refer to a position or orientation relative to the treating clinician. "distal" or "distally" refers to a location remote from the clinician applying the treatment. "proximal" and "proximally" refer to a location near the clinician applying the treatment. The term "patient" refers to a human patient or an animal patient. The term "clinician" or "treating clinician" refers to a doctor, nurse, or other care provider and may include support personnel. The term "occlusion" refers to a complete, near complete or partial occlusion of a blood vessel.

The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms "including" and "in which" are used as the plain-english equivalents of the respective terms "comprising" and "wherein. Furthermore, in the following claims, the terms "comprising" and "including" are open-ended; that is, a device, kit, or method that includes features or components in addition to those listed after this term in the claims is still considered to fall within the scope of the claims. Furthermore, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. It will be appreciated that although certain dependent claims may be presented in a single dependent form, features of those claims may be combined as if the claim were multiple dependent forms.

The abstract is provided to allow the reader to quickly ascertain the nature of the technical disclosure. The Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Claims (9)

1. An infusion catheter, comprising:

a balloon comprising an expandable tube wound in a helical manner about a central axis into a series of windings, the inner surface of the series of windings defining a channel through the center of the helix for delivery of a medical device or maintenance of blood flow when expanded;

an elongate shaft extending from a proximal portion to a distal portion having an inner surface defining a lumen for providing inflation fluid to or withdrawing inflation fluid from the inflatable tube and an outer surface attached to the proximal portion of the inflatable tube;

the elongate shaft is eccentrically disposed relative to the channel and its lumen is in fluid communication with the interior of the inflatable tube; and

a guidewire support tube having a guidewire lumen therein, the guidewire lumen extending within the channel and being non-coaxial with the lumen of the elongate shaft.

2. The perfusion catheter of claim 1, further comprising means for attaching an outer surface of the elongate shaft to the polymer of the expandable tube, the means for attaching forming a fluid-tight seal between the elongate shaft and the expandable tube.

3. The perfusion catheter of any one of claims 1 or 2, wherein the length of the guidewire lumen is about equal to or slightly longer than the length of the channel.

4. The perfusion catheter of any one of claims 1-3, wherein adjacent windings of the series of windings are stacked upon one another and bonded to one another.

5. The perfusion catheter of any one of claims 1-4, wherein the expandable tube comprises an inner tube and an outer tube, the inner tube being formed of a polymer having sufficient radial stiffness to resist collapsing or rupturing when exposed to an expansion pressure, and the outer tube being formed of a polymer configured to exhibit adhesive properties when heated.

6. The perfusion catheter of claim 5, wherein the inner and outer tubes are co-extruded.

7. The perfusion catheter of any one of claims 5 or 6, wherein the polymer of the inner tube is crosslinked and the polymer of the outer tube is non-crosslinked.

8. The perfusion catheter of claim 7, wherein the polymer of the inner tube has a higher melting temperature than the polymer of the outer tube.

9. The perfusion catheter of claim 7, wherein the outer surface of the elongate shaft is attached to the inflatable tube such that at the attachment both the inner tube and the outer tube are radially closer to the outer surface of the elongate shaft than the inner surface of the elongate shaft.