Methods and apparatus for minimizing excessive drug delivery

Abstract

Apparatus and methods are disclosed for providing suction within a patient's body during delivery of a drug-coated treatment device to assist in the removal of detached drug coating into the patient's blood. The drug treatment device can be a drug-coated balloon, a drug-coated stent, or similar device. The device can include an occlusion balloon useful for containing detached drug coating, and suction can be provided proximal or distal, or both proximal and distal, to the drug-coated balloon during the procedure.

Description

Related Applications

[0001] This application claims the benefit and priority of U.S. Provisional Application No. 62 / 950,039, filed on December 18, 2019, under the title "Minimization of Drug Deposition During Drug Delivery Procedures", which is hereby incorporated by reference in its entirety. BACKGROUND OF THE INVENTION

[0002] In various vascular procedures, devices coated with drugs are utilized to deliver the drug or a similar substance to a specific portion of the tissue within a patient's body. These drugs are often used for the treatment or prevention of stenosis, restenosis, sclerosis, or similar vascular diseases.

[0003] In one specific example, for the purpose of such drug delivery, a balloon catheter can be used. The balloon of the catheter includes a drug coating on its outer surface, and when inflated, by pressing the drug coating against the inner surface of the blood vessel, at least a portion of the drug coating is applied to the contacted tissue. In another example, a stent includes a drug coating on its surface, and when the stent expands and contacts the vascular tissue, this drug is applied and can be absorbed by the tissue.

[0004] Although the drug coating on such devices remains an important method of drug delivery to the target area of the vascular system, a significant portion of the drug coating may detach or be released during the delivery procedure. If the drug detaches, it may move to many unintended locations within the patient's blood and vascular system, thereby causing undesirable complications to the patient.

[0005] For example, paclitaxel may be included in the drug coating of a balloon catheter for the treatment of restenosis or vascular stenosis. Paclitaxel is particularly suitable for application via a balloon catheter because of its high concentration and rapid release from the coating. However, treatment with paclitaxel via a balloon or stent is also associated with an increased risk of death. One possible cause of this increased mortality is that paclitaxel may be released into the patient's bloodstream and migrate to organs that are particularly sensitive to the drug, such as the lungs. In treatment cases where the concentration of paclitaxel in the drug coating is relatively high, measurable concentrations of paclitaxel in the patient's blood may remain for more than 30 days.

[0006] Unintended release of the drug from the drug coating is further complicated by the properties of the coating itself. If the coating is difficult to detach from the device, very little drug will be released into the patient's tissue. If the coating detaches easily, most of the drug may circulate within the patient's vascular system. Thus, delivery of the desired amount of drug using such a coating often necessarily involves the release of some, or a significant portion, of the drug into the bloodstream.

[0007] In fact, the present applicants conducted experiments and analyses and obtained the following statistics. Less than 1% of the drug is transferred from a typical balloon coating to the target tissue area, while only about 16% of the coating remains on the balloon after the procedure is completed. Approximately 25% of the drug coating detaches while guiding the balloon catheter through the guide catheter, and approximately 59% of the drug coating detaches during balloon inflation, deflation, and removal from the catheter. As a result, it is thought that approximately 84% of the drug coating detaches from the balloon during the procedure and disperses throughout the patient's vascular system and organs. Depending on the type of drug coating, the concentration of the drug in the coating, and the type of balloon (or other device), a significant amount of the drug may often be measured in the patient's blood for a certain period after treatment.

[0008] For at least these reasons, there is a need for improved methods and devices for treating that reduce the amount of drug inadvertently released into the patient's bloodstream during treatment. SUMMARY OF THE INVENTION

[0009] At least one aspect is directed to a device for performing aspiration within a patient's body during delivery of a drug-coated treatment device to assist in removing a drug coating that has detached into the patient's blood. The drug-coated treatment device can be a drug-coated balloon, a drug-coated stent, or a similar device.

[0010] At least one aspect is directed to a treatment system and method of use that creates aspiration at or near the distal portion of a drug-coated treatment device, at or near the proximal portion of the drug-coated treatment device, or at each of both locations. The aspiration can occur while advancing the delivery device distally within the patient's vasculature, while radially expanding / implanting the drug-coated treatment device, while retracting the drug-coated treatment device proximally, and / or at any time during or near the intervals between these periods.

[0011] At least one aspect is directed to a method and treatment system having a balloon catheter with a proximal drug-coated balloon configured to expand against a blood vessel and a distal occlusion balloon configured to occlude the blood vessel. The treatment system may further comprise a guide catheter (or, alternatively, a guide sheath or introducer sheath) configured to aspirate material from its distal end during the procedure.

[0012] At least one aspect is directed to a method and a treatment system having a balloon catheter with sequentially inflating balloons. The balloon has a distal portion that inflates first, which generally has no drug coating. The balloon also has a proximal portion that inflates second, which has a drug coating. The treatment system may further comprise a guide catheter (or, alternatively, a guide sheath or introducer sheath) configured to aspirate material from its distal end during the procedure.

[0013] At least one aspect is directed to a method and a treatment system having a balloon catheter with a drug-coated balloon and a guide wire lumen configured to aspirate from the distal end of the balloon catheter. The guide wire lumen may have a relatively large diameter and be connectable to a suction source. The balloon catheter may be used, as needed, with an occlusion balloon disposed proximally and / or a guide catheter (or, alternatively, a guide sheath or introducer sheath) configured to perform aspiration.

[0014] At least one aspect is directed to a method and a treatment system having a balloon catheter with a suction passage that extends through a drug-coated balloon and is selectively connected to a guide catheter (or, alternatively, a guide sheath or introducer sheath) to enable aspiration. The guide catheter is configurable to perform aspiration, its distal end is connectable to the suction passage, and enables aspiration on the distal side of the drug-coated balloon. Optionally, an occlusion balloon can be advanced through the suction passage and used on the distal side of the drug-coated balloon. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] These and other aspects, features, and advantages made possible by embodiments of the present invention will become apparent and obvious from the following description of embodiments of the present invention with reference to the accompanying drawings.

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Mode for Carrying Out the Invention

[0031] With reference to the accompanying drawings, specific embodiments of the present invention will be described below. However, the present invention may be embodied in many different forms and should not be construed as limited to the embodiments described herein. These embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. The terms used in the detailed description of the embodiments shown in the accompanying drawings are not intended to limit the present invention. In the drawings, like numbers refer to like elements. Although various embodiments are described, the features of each embodiment can be used in place of those of the other described embodiments. In other words, any of the features of the embodiments can be mixed or combined with each other, and the embodiments should not necessarily be construed as strictly including only the features shown or described.

[0032] In this specification, the terms drug and drug coating are used, but these terms are intended to include any therapeutic agent, compound, chemical substance, or other substance that can be included in a coating on a device.

[0033] As described above, drug-coated devices, such as balloon catheters and stents, often release an undesirable amount of drug coating into the blood during a treatment procedure, and this drug then circulates through the patient's vasculature. Much of such undesirable drug release can occur when guiding a device (e.g., a balloon or a stent) through an outer guide catheter, during expansion of the device within the patient's blood vessel, during contraction of the device, and during retraction into the guide catheter.

[0034] One specific example of such an undesirable loss of drug coating can be seen in FIGS. 1 and 2. FIG. 1 shows a typical balloon catheter 100 having a drug-coated balloon 106 disposed at the distal end of an elongate catheter body 102. The catheter body 102 also includes a guide wire passage 104 that opens proximal and distal to the balloon 106, and a balloon inflation lumen (not shown) that communicates between the interior of the balloon 106 and a proximal catheter hub 108 to enable inflation of the balloon. The configuration of this guide wire passage 104 is generally referred to as a rapid exchange type catheter, although an over-the-wire type catheter having an opening of the guide wire passage at the proximal end of the catheter is also contemplated.

[0035] Referring to FIG. 2, typically, the balloon catheter 100 is advanced out of an outer covering guide catheter 110 to position the drug-coated balloon 106 adjacent to the blood vessel wall in the target treatment area. By injecting an inflation medium into the inflation lumen, the drug-coated balloon 106 is inflated to contact the blood vessel wall, and at least a portion of the drug coating is delivered to the blood vessel wall. Finally, the drug-coated balloon 106 is contracted and retracted into the outer covering guide catheter 110. Although a guide catheter is used throughout this specification, it should be understood that a guide sheath or an introducer sheath can be used instead of this component throughout this specification.

[0036] As shown in FIG. 2, most of the drug coating 109 is released from the balloon 106 during this treatment procedure, mixes with the patient's blood, and circulates through at least a portion of the patient's vasculature and organs such as the heart and lungs. Depending on the type of drug, the amount released from the balloon, the treatment site, and other factors, a significant concentration of the drug, which may be undesirable, may remain in the patient's blood and / or organs for several days or weeks after the treatment procedure.

[0037] This specification describes several treatment devices and methods for suppressing the undesirable accumulation of drugs detached from the coating of a treatment device. Although various embodiments of mainly balloon catheters are described, the devices and methods of the present invention can be similarly adapted for use with other drug-coated devices such as stents, and can also be similarly adapted for use with devices that are not coated and directly deliver drugs to the target area (e.g., an exudation balloon configured to discharge drugs from its pores).

[0038] FIGS. 3 and 4 show one embodiment of a treatment system 120 configured to aspirate or remove at least a portion of the drug coating released into the patient's vasculature during a treatment procedure. The treatment system 120 includes a balloon catheter 121 having an occlusion balloon 124 configured to occlude the distal portion of the patient's target blood vessel prior to inflation of the drug coating balloon 126. As described in detail below, the blood containing the drug coating detached or released during the procedure is aspirated and removed from the patient to prevent circulation through the patient's blood vessels.

[0039] The occlusion balloon 124 is located distally of the drug - coated balloon 126 on the elongated body 122 of the balloon catheter 121. The balloons 124, 126, and the elongated body 122 are configured to fully inflate the occlusion balloon 124 before significant inflation of the drug - coated balloon 126 and to deflate the occlusion balloon 124 after deflation of the drug - coated balloon 126. Such an inflation sequence is effective in keeping the blood vessel occluded during the part of the procedure where the drug coating is most likely to detach into the patient's blood. For example, the occlusion balloon 124 is effective in preventing distal movement of the drug from the drug - coated balloon 126 and / or, as will be described in more detail, is effective in providing a seal for a subsequent aspiration procedure. In one example, this inflation sequence can be achieved using two separate inflation lumens within the elongated body 122, each of these inflation lumens being connected at the proximal end of the elongated body 122 to a separate inflation lumen and inflation port (e.g., port 123A and port 123B).

[0040] In another example, both balloons 124, 126 may be connected to a single inflation lumen within the body 122. To produce the desired inflation sequence, the occlusion balloon 124 may be composed of a material that is more easily inflated than the drug - coated balloon 126. In one specific example, the occlusion balloon 124 is composed of a relatively non - elastic material such that its diameter increases with little resistance (similar to inflating a plastic bag, for example), while the drug - coated balloon 126 is composed of a relatively elastic material that stretches and provides resistance during inflation (similar to a rubber party balloon, for example). Thus, as the pressure within the inflation lumen increases, first the occlusion balloon 124 inflates, then the drug - coated balloon 126 inflates, first the drug - coated balloon 126 deflates, and then the occlusion balloon 126 deflates.

[0041] In any of the foregoing examples of balloon inflation, the proximal end of the elongated body 122 (e.g., the catheter hub) may be connected to one or more syringes manually operated to cause inflation, or to an electric inflation device. In the case of an electric inflation device, the order of inflation of the two balloons 124, 126 is determined by different levels of pressure within the inflation lumen (e.g., at low pressure, only the occlusion balloon 124 is inflated, and at high pressure, the drug-coated balloon 126 is also inflated), so in particular in the example of the single inflation lumen described above, it may be desirable to provide and maintain various pressure levels within the inflation lumen and the balloons. In this regard, the electric inflation device may be provided with an algorithm configured to provide a predetermined sequence of pressure levels in order to achieve the desired order of inflation and deflation of the balloons.

[0042] As described above, the treatment system 120 is configured to perform suction to remove blood in the vicinity of the drug-coated balloon, including some of the detached drug coating 128. In this embodiment, this suction can be provided via an outer guide catheter 130 or sheath through which the balloon catheter 121 is disposed. The guide catheter 130 may generally have a tubular body and be provided with a suction port 132 opening into the internal lumen of the guide catheter 130 so that a vacuum source such as a syringe 136 or a pump can be connected thereto. When the vacuum source is activated, blood is drawn into the lumen of the guide catheter 130 from its distal end and towards the vacuum source. The guide catheter typically has a hemostatic valve at its proximal end (e.g., surrounding the balloon catheter 121), preventing air from being drawn into the lumen of the guide catheter 130. In other words, the guide catheter 130 is configured to allow suction only from its distal end towards the vacuum source, not from its proximal end. In this embodiment, continuous occlusion of the blood vessel is effective in preventing the detached drug particles from moving through the patient's vascular system before the guide catheter 130 can suction them from the patient.

[0043] When using the syringe 136 as a vacuum source, the physician may first keep the stopcock valve 134 disposed between the syringe 136 and the guide catheter 130 in a closed position. It is possible to generate a negative pressure by pulling the plunger of the syringe 136, and then, when suction within the patient becomes necessary, the stopcock valve 134 can be opened. Next, blood from the region near the drug-coated catheter 126 is drawn into the guide catheter 130 and further into the syringe 136. Depending on the treatment location, the properties of the drug coating, and other factors, various amounts of blood may be aspirated. In many cases, a 30 cc or 60 cc syringe or suction capacity may be appropriate.

[0044] In one example, the treatment system 120 can be used by first advancing a guide wire into the patient's vasculature such that its distal end is positioned near the desired treatment site within the blood vessel. Next, the guide catheter 130 can be advanced along the guide wire such that its distal end is positioned near the desired treatment site. Thereafter, by advancing the balloon catheter 121 along the guide wire through the guide wire passage 122A, the drug-coated catheter 126 is positioned at the desired target site and the occlusion balloon 124 is positioned distally from the target site. If necessary, the guide wire can be withdrawn prior to inflation of the balloons 124, 126.

[0045] Next, the occlusion balloon 124 is inflated to occlude the blood vessel and substantially prevent blood from flowing therethrough. When the blood vessel is occluded, as shown in Figure 3, the drug-coated balloon 126 is inflated and the drug coating 128 on the balloon 126 contacts the inner surface of the blood vessel and this drug coating is delivered or imparted to the tissue of the blood vessel.

[0046] As described above, during the process of threading the balloon catheter 121 through the guiding catheter 130, the process of inflating the drug-coated balloon 126, the process of deflating the drug-coated balloon 126, and other movements during the procedure, a significant portion of the drug coating 128 may become detached or released. In this regard, when the drug-coated balloon 126 is (partially or fully) deflated, the physician can perform suction through the guiding catheter 130. Note that the suction may be performed throughout the entire process of movement and inflation. Also in this case, such suction can be generated, among other ways, by opening the valve 134 connected to the syringe 136 with the plunger pulled back.

[0047] As shown in FIG. 4, the blood and the detached drug coating 128 are drawn into the guiding catheter 130, exit from the port 132, and are drawn into the syringe 136 (however, some blood and a part of the drug coating may remain in the guiding catheter 130). In one example, the physician may remove 30 to 60 milliliters of blood from the region between the occlusion balloon 125 and the distal end of the guiding catheter 130. Finally, the drug-coated balloon 126 is fully deflated (if not yet fully deflated), the occlusion balloon 124 is also fully deflated, and the physician can pull the balloon catheter 121 proximally back into the guiding catheter 130 to complete the procedure. Thus, much of the detached drug coating that would otherwise circulate in the patient's vasculature is removed from the patient.

[0048] Figures 5 to 10 show another embodiment of the balloon catheter 140, which has a sequentially inflatable single balloon 146 that can first be partially inflated to occlude a portion of the patient's blood vessel and then fully inflated to deliver a therapeutic agent to the tissue of the blood vessel. Similar to the aforementioned balloon catheter 121, this can occlude a portion of the patient's blood vessel to prevent the movement of the detached agent, and then some of the detached agent in the patient's blood can be aspirated and removed.

[0049] As shown in FIGS. 5 and 6, the balloon catheter 140 includes an elongated body 142 having a guide wire passage 144 (e.g., a rapid exchange type and monorail form guide wire passage) extending therethrough at least in its distal portion, and a balloon 146 disposed near the distal end of the elongated body 142.

[0050] The drug coating is disposed on the balloon proximal portion 146B so as to be able to apply the drug to the patient's blood vessel, while the balloon distal portion 146A contains little or no drug coating. Accordingly, the balloon distal portion 146A can be inflated to occlude the blood vessel, and the drug coating that detaches from the catheter 140 and moves distally from this portion is minimal, if any.

[0051] As shown in FIGS. 7 to 10, the balloon catheter 140 is configured to sequentially inflate and deflate the balloon distal portion 146A and the balloon proximal portion 146B. Specifically, first the balloon distal portion 146A is inflated, then the balloon proximal portion 145B is inflated, then the balloon distal portion 146A is deflated, and then the balloon proximal portion 145B is deflated.

[0052] Such sequential inflation of the balloon can be achieved in several different ways. For example, each part 146A, 146B of the balloon 146 can be constructed of a material that allows the distal portion 146A of the balloon to inflate (i.e., be more easily inflated) at a lower pressure than the proximal portion 146B of the balloon. Such a difference in resistance to inflation between the two parts 146A, 146B can be achieved by different materials, different material thicknesses, additional layers / banding materials applied to the proximal portion 146B, any combination of these techniques, or similar techniques. Also, the elongated body 142 may comprise a single inflation lumen that communicates with the balloon 146 to allow for this order of inflation / contraction. Similar to the previous embodiments, the inflation mechanism can be a manually actuated device such as a syringe, or an electrically powered inflation device that can be programmed to achieve and hold specific desired pressures required for sequential inflation.

[0053] In another example, the balloon 146 may comprise a mechanism that feeds and discharges the inflation medium at different rates to the distal portion 146A and the proximal portion 146B of the balloon to cause sequential inflation. This can be achieved using a large distal inflation port and a small proximal inflation port provided in the elongated body 142 inside the balloon 146, a partial or complete wall within the balloon that separates the two parts 146A, 146B, distal and proximal inflation ports having valves that open in different amounts, separate inflation lumens within the elongated body 142, or a combination of these features.

[0054] The balloon catheter 140 can be used in the following exemplary procedure. First, advance a guide wire within the patient's body and position its distal end near the target region of the patient's blood vessel. Next, advance an elongate tubular guide catheter 148 along the guide wire and position the distal end of the guide catheter 148 in proximity to the target region. Next, advance the balloon catheter 140 along the guide wire and through the internal lumen of the guide catheter 148, and position its distal end and the balloon 146 in the target region of the patient's blood vessel. It is preferred that the distal portion 146A is positioned distally of the target region while the proximally drug-coated portion 146B is positioned along the inner circumference within the target region of the blood vessel.

[0055] Referring to FIG. 7, first inflate the distal portion 146A of the balloon 146 to completely or substantially occlude the blood vessel. As shown in FIG. 8, inflate the proximally drug-coated portion 146B so that its drug-coated surface is expanded against the target region of the blood vessel and a portion of the drug is applied or delivered.

[0056] Referring to FIG. 9, when the balloon proximal portion 146B is partially or fully deflated, the detached drug coating 143 remains in the blood retained near the balloon 146. At this point, aspiration is performed via the guide catheter 148, although aspiration can also be performed earlier than this point. This aspiration can be performed using a similar device in a similar manner as described for the guide catheter 130 above.

[0057] Finally, as shown in FIG. 10, the balloon 146 can be fully Contraction deflated and withdrawn into the guide catheter 148 to complete the procedure. Aspiration can continue, if necessary, during this full deflation and balloon withdrawal to further remove any potentially detaching drug coating.

[0058] Figures 11 - 13 show another embodiment of the balloon catheter 150, which is configured to assist in removing a portion of the detached drug coating 156 by suction through its distal end. Such distal suction can be used, if desired, in conjunction with proximal suction of the balloon 154 from a guide catheter (such as the aforementioned guide catheters 130 and 148).

[0059] The balloon catheter 150 may comprise an elongated body through which a guide wire passage configured to also function as a suction passage extends internally. This passage may have a proximal opening 157 within the catheter hub 151 that allows the guide wire to enter the passage, and may also have a distal opening 158 that allows the guide wire to exit the passage. The catheter hub 151 may have a suction port 153 that is also in communication with the guide wire passage and connectable to a vacuum source such as a syringe 136. A hemodynamic valve in the proximal portion of the guide wire passage seals the proximal end of the passage, so that when negative pressure is applied to the guide wire passage, suction or inhalation occurs from the distal opening 158 of the balloon catheter 150.

[0060] If desired, the guide wire passage has a somewhat larger diameter than a typical guide wire passage to prevent clogging during suction and to ensure that blood can be reliably removed at a desired rate by suction. In one example, the diameter ratio of the guide wire / suction passage to the inflated balloon 154 is in the range of about 0.2 - 0.8. Examples of some ratios and measurements for a prior art guide wire lumen and the size of the larger guide wire passage according to this embodiment are shown in Table 1 below. For example, for a guide wire lumen with a diameter size of 0.036 mm and a balloon diameter size of 2 mm, the ratio is 0.18, while for a Rumen diameter of 1.22 mm and a balloon diameter of 2 mm, the ratio is 0.61.

[0061] Table 1 JPEG0007682892000001.jpg69166

[0062] The balloon catheter 150 can be used in the following exemplary procedure. First, advance a guide wire within the patient's body and position its distal end in the vicinity of the target area of the patient's blood vessel. Next, advance an elongate tubular guide catheter (similar to guide catheter 130 or guide catheter 148) along the guide wire and position the distal end of the guide catheter in proximity to the target area. Next, pass the guide wire and advance the balloon catheter 150 through the internal lumen of the guide catheter, and position its distal end and the balloon 154 in the target area of the patient's blood vessel.

[0063] Referring to FIG. 12, the balloon 154 is inflated such that its drug coating 156 is pressed against the tissue of the target area. While advancing the balloon 154 out of the guide catheter and inflating it, suction from the guide catheter (suction as described for the previous embodiments), and / or suction from the distal opening 158 of the guide wire lumen can be used to assist in collecting some of the drug coating 156 that has detached during this time.

[0064] Referring to FIG. 13, the balloon 154 can be deflated after the desired period of contact with the target area. Since this deflation may cause some additional drug coating (shown in the blood as element 159) to detach, additional suction is effective for capturing and suctioning drug particles and blood from the distal end of the catheter 150. The suction according to this embodiment may be only through the distal opening 158, or may be performed in combination with suction from the guide catheter at various times throughout the procedure.

[0065] When performing suction from both the distal opening 158 and the guide catheter, it may be desirable to apply different negative pressures from each source depending on the desired strength of the intended suction. For example, in order to prevent the patient's blood vessels from collapsing, it is desirable to use a relatively small and gentler negative pressure from the distal opening 158, while a relatively strong vacuum source from the guide catheter makes it less likely for blood vessel collapse to occur due to the balloon catheter extending distally from the opening of the guide catheter.

[0066] Figures 14 and 15 show another embodiment of the treatment system, which enables selective suction on the proximal and distal sides of the drug-coated balloon 162 during treatment. Specifically, the drug-coated balloon catheter 160 is configured to be coupled, i.e., in a sealed engagement, with the distal opening of the guide catheter 130 connected to the suction source. With such a configuration, as shown in Figure 15, when the guide catheter 130 is detached from the balloon 162, suction can be performed on the proximal side of the balloon 162, and when engaged with the proximal end of the balloon 162, suction can be performed on the distal side of the balloon 162 via the passage 164.

[0067] In one embodiment, the drug-coated balloon catheter 160 includes an elongated catheter body 168 whose distal end is connected to an enlarged tubular portion having a passage 164. The balloon 162 is connected to the enlarged tubular portion and is configured to expand via an inflation lumen within the elongated catheter body 168.

[0068] Balloon 162 is configured such that the distal portion 162A of the balloon has a larger inflation diameter and the proximal portion 162B of the balloon has a relatively smaller inflation diameter. The diameter of the distal portion 162A of the balloon during inflation is preferably large enough to contact the inner peripheral surface of the target blood vessel so that a part of its drug coating 166 can be delivered. The diameter of the proximal portion 162B of the balloon during inflation has a diameter approximately the same size as (e.g., slightly larger than, equal to, or slightly smaller than) the inner diameter of the inner lumen of the guide catheter 130. With such a size, the inflated proximal portion 162B of the balloon can be fitted and locked inside the guide catheter 130. Therefore, when suction is performed with the guide catheter 130, suction is connected from the distal opening 164B to the outside through the proximal opening 164A of the passage 164. Alternatively, the proximal portion 162B of the balloon may be inflated in a conical or inclined surface shape and increase in size toward the distal direction so as to "wedgingly" enter the inner lumen of the guide catheter 130.

[0069] Optionally, the passage 164 has a diameter large enough to accommodate the occlusion balloon catheter 170 passing through it in order to occlude the area of the blood vessel on the distal side of the balloon 162, similar to the foregoing embodiments. In one example, the passage 164 has a diameter that can accommodate a 0.014-inch (0.035 cm) balloon. Therefore, the balloon may have an inner diameter of about 0.050 inches (0.13 cm). In this regard, the passage 164 may have a diameter that provides a sufficient gap around the body 172 of the balloon catheter 170, so that suction through the passage 164 can occur even while the balloon catheter 170 is inside the passage 164.

[0070] The balloon catheter 160 can be used in the following exemplary procedure. First, the guide wire 111 is advanced within the patient, and its distal end is positioned near the target region of the patient's blood vessel. Next, the elongate tubular guide catheter 130 is advanced along the guide wire 111, and the distal end of the guide catheter 130 is positioned adjacent to the target region. Next, the drug-coated balloon catheter 160 is advanced along the guide wire (through passageway 164) and through the internal lumen of the guide catheter 130, and its distal end and balloon 162 are positioned in the target region of the patient's blood vessel.

[0071] Optionally, the occlusion balloon catheter 170 is advanced along the guide wire 111 and through the passageway 164 of the drug-coated balloon catheter 160. Next, the occlusion balloon 174 is inflated to contact the region of the patient's blood vessel distal to the target region and occlude this region. Such a configuration can be seen in FIG. 15.

[0072] Next, the balloon 162 of the drug-coated catheter 160 is inflated such that the drug coating 166 on its balloon distal portion 162A contacts the target region of the patient's blood vessel. During this time, the distal end of the guide catheter 130 may be positioned proximally away from the balloon 162, and suction can be performed in the manner described above in other embodiments.

[0073] Next, by moving the distal end of the guide catheter 130 distally toward the balloon 162, its lumen can be made to surround and overlap the small-diameter portion 162B of the balloon 162. Next, if suction through the guide catheter 130 is not yet activated, it is activated to create suction in the space between the occlusion balloon 174 (if present) and the drug-coated balloon 162. Accordingly, the detached drug coating present in the blood between the two balloons 162, 174 is partially or completely removed.

[0074] Once the desired amount of aspiration has been achieved, the drug-coated balloon 162 is deflated and withdrawn into the guide catheter 130. Similarly, the occlusion balloon 174 can be deflated and withdrawn into the guide catheter 130 to complete the procedure.

[0075] In an alternative embodiment, either the drug-coated balloon and / or the occlusion balloon of the foregoing embodiments can be replaced with a non-inflatable device such as an expandable mesh device.

[0076] In an alternative embodiment, the drug-coated balloon and the balloon catheter of the foregoing embodiments can be replaced with a drug-coated stent (or similar implantable device) and a stent delivery catheter.

[0077] In an alternative embodiment, the drug-coated balloon and the balloon catheter of the foregoing embodiments can be replaced with a balloon catheter having a balloon that "oozes" or slowly releases a liquid drug from holes in the surface of the balloon.

[0078] The procedures described in this embodiment may be performed at many different locations in a patient's vasculature, but may be particularly useful for procedures in the arms, legs, and torso.

[0079] Although the invention has been described with respect to specific embodiments and uses, those skilled in the art will be able to generate additional embodiments and variations without departing from the spirit of the claimed invention or exceeding the scope of the claimed invention in light of this teaching. Accordingly, it should be understood that the drawings and the description herein are provided by way of example to facilitate understanding of the invention and should not be construed as limiting the scope of the invention.

Claims

1. A guide catheter comprising an elongated tubular body, the guide catheter having a suction port in fluid communication with an internal guide catheter lumen, and a balloon catheter comprising an elongated catheter body, a balloon connected to a distal region of the elongated catheter body, and an enlarged tubular portion connected to the distal region of the elongated catheter body, the balloon catheter having a first suction position at which a proximal portion of the balloon seals with a distal opening of the internal guide catheter lumen and the enlarged tubular portion is in direct fluid communication with the internal guide catheter lumen and the suction port, the balloon catheter having a second suction position at which the proximal portion of the balloon is disengaged from sealing engagement with the distal opening of the internal guide catheter lumen and the enlarged tubular portion is in indirect fluid communication with the internal guide catheter lumen and the suction port, A vascular treatment system.

2. The vascular treatment system according to claim 1, wherein the balloon has a distal portion on which a drug coating is disposed and a proximal portion sized to fit and lock within the internal guide catheter lumen when inflated.

3. The vascular treatment system according to claim 1, wherein the balloon is connected to the enlarged tubular portion.

4. The vascular treatment system according to claim 1, wherein the distal portion of the balloon has a fully inflated diameter that is larger than the fully inflated diameter of the proximal portion.

5. The vascular treatment system according to claim 1, wherein the fully inflated diameter of the proximal portion of the balloon is slightly larger than, the same as, or slightly smaller than the internal guide catheter lumen.

6. The vascular treatment system according to claim 1, further comprising an occlusion balloon located on the distal side of the balloon and inflatable to occlude a location on the distal side of the balloon.

7. The vascular treatment system according to claim 1, further comprising an occlusion balloon catheter disposed through the enlarged tubular portion, the occlusion balloon catheter having an occlusion balloon located on the distal side of the balloon and inflatable to occlude a location on the distal side of the balloon.

8. The vascular treatment system according to claim 7, wherein the inner diameter of the enlarged tubular portion is 0.050 inches. **Claim 9** The vascular treatment system according to claim 1, wherein the balloon has holes for releasing a liquid drug when the balloon is inflated. **Claim 10** The vascular treatment system according to claim 1, wherein the balloon has a conical or inclined surface shape that increases in size toward the distal side when inflated. **Claim 11** The vascular treatment system according to claim 1, wherein the distal portion of the balloon is provided with a drug coating or a drug-coated stent. **Claim 12** The vascular treatment system according to claim 1, wherein the first suction position sucks on the distal side of the balloon, and the second suction position sucks on the proximal side of the balloon.

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