Method and apparatus for minimizing excess drug delivery

Abstract

A device and method for suctioning within a patient during delivery of a drug coated therapeutic device to help remove shed drug coating from the patient's blood is described. The drug therapeutic device can be a drug coated balloon, a drug coated stent, or similar device. The device can include an occlusion balloon to help contain the shed drug coating, and suction can be applied proximal, distal, or both proximal and distal of the drug coated balloon during the procedure.

Description

[0001] Related applications

[0002] This application claims the benefit and priority of U.S. Provisional Application No. 62 / 950,039, filed on December 18, 2019, entitled “Minimizing Drug Deposits During Drug Delivery Procedures,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to methods and apparatus for minimizing excessive drug delivery. Background Technology

[0004] Many vascular surgeries utilize drug-coated devices to deliver drugs or similar substances to specific parts of a patient's tissues. These drugs are commonly used to treat or prevent stenosis, restenosis, hardening, or similar vascular conditions.

[0005] In one specific example, a balloon catheter can be used for such drug delivery purposes. The balloon of the catheter includes a drug coating on its outer surface, which, when inflated, presses the drug coating against the inner surface of the blood vessel so that at least some of the drug coating is applied to the tissue in contact. In another example, a stent may include a drug coating on its surface, which is applied to the vascular tissue against which the stent extends, thereby allowing the drug to be absorbed by the tissue.

[0006] While drug coatings on such devices remain an important method for delivering drugs to target areas of the vascular system, a significant portion of the coating can detach or be released during delivery. Once released, the drug can migrate within the patient's bloodstream and vascular system to many unintended locations, potentially causing adverse complications.

[0007] For example, paclitaxel is sometimes incorporated into the drug coating of balloon catheters to treat restenosis or vascular stenosis. Paclitaxel is particularly well-suited for application via balloon catheters due to its high concentration and rapid release from the coating. However, paclitaxel treatment via balloons and stents also increases the risk of death. One possible reason for increased mortality is the release of paclitaxel into the patient's bloodstream, which can then enter organs particularly sensitive to the drug, such as the lungs. In cases of treatment with relatively high concentrations of paclitaxel in the drug coating, measurable paclitaxel concentrations in the patient's blood may remain for 30 days or longer.

[0008] The nature of the coating itself complicates the unintended release of drug from the drug coating. If the coating is too difficult to remove from the device, little drug is released into the patient tissue. If the coating is too easy to remove, much of the drug can end up circulating in the patient's vascular system. Thus, delivering the desired amount of drug with such a coating often requires releasing some or even most of the drug into the bloodstream.

[0009] In fact, the applicants have conducted experiments and analysis and determined the following statistics: less than 1% of the drug is transferred from the particular balloon coating to the target tissue area, and only about 16% of the coating remains on the balloon after the procedure is complete. About 25% of the drug coating is removed while tracking the balloon catheter through the guide catheter, and about 59% of the drug coating is removed during balloon inflation, deflation, and removal from the catheter. Thus, approximately 84% of the drug coating is removed from the balloon during the procedure and is believed to be distributed throughout the patient's vascular system and organs. Depending on the type of drug coating, the concentration of drug in the coating, and the type of balloon (or other device), a significant amount of drug can be measured in the patient's blood for some time after treatment.

[0010] For at least these reasons, there is a need for improved treatment methods and devices to reduce the amount of drug unintentionally released into a patient's bloodstream during treatment. SUMMARY

[0011] At least one embodiment is directed to a device for suctioning within a patient during delivery of a drug-coated treatment device to help remove drug coating that is shed into the patient's bloodstream. The drug treatment device can be a drug-coated balloon, a drug-coated stent, or similar device.

[0012] At least one embodiment is directed to a treatment system and method of use that generates suction near a distal portion of a drug-coated treatment device, near a proximal portion of a drug-coated treatment device, or a combination of both locations. The suction can occur at any point in time while advancing the delivery device distally within the patient's vascular system, while radially expanding / implanting the drug-coated treatment device, while proximally withdrawing the drug-coated treatment device, and / or at times between or proximate thereto.

[0013] At least one embodiment 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 can also include a guide catheter (or optionally a guide sheath or a guide sheath catheter) configured to suction material from a distal end thereof during a procedure.

[0014] At least one embodiment relates to a method and treatment system with a balloon catheter having sequentially inflated balloons. The balloon has a distal portion that is inflated first and is generally free of a drug coating. The balloon also has a second inflated proximal portion and includes a drug coating. The treatment system can also include a guide catheter (or optionally a guide sheath or introducer sheath) configured to aspirate material from its distal end during a procedure.

[0015] At least one embodiment relates to a method and treatment system with a balloon catheter having a drug coated balloon and a guide wire lumen configured to aspirate from the distal end of the balloon catheter. The guide wire lumen can have a relatively large diameter and can be connected to an aspiration source. The balloon catheter is optionally used with a proximally placed occlusion balloon and / or a guide catheter (or optionally a guide sheath or introducer sheath) configured to also provide aspiration.

[0016] At least one embodiment relates to a method and treatment system with a balloon catheter having an aspiration channel through a drug coated balloon and can be selectively connected to a guide catheter (or optionally to a guide sheath or introducer sheath) to create an aspiration therein. The guide catheter can be configured to provide aspiration with its distal end connectable to the channel of the aspiration channel, allowing aspiration of the drug coated balloon distally. Optionally, an occlusion balloon can be advanced through the aspiration channel and used distal to the drug coated balloon. BRIEF DESCRIPTION OF DRAWINGS

[0017] These and other aspects, features, and advantages of the present embodiments will become apparent from the following description of the present embodiments, taken in conjunction with the accompanying drawings:

[0018] Figure 1 is a side view of a balloon catheter;

[0019] Figure 2 is a side view of a balloon catheter within a guide catheter;

[0020] Figure 3 is a side view of a dual balloon catheter within a guide catheter;

[0021] Figure 4 is a side view of a dual balloon catheter; Figure 3

[0022] Figure 5 is a side view of a sequentially inflated balloon catheter;

[0023] Figure 6 is a side view of a sequentially inflated balloon catheter; Figure 5

[0024] is a side view of a sequentially inflated balloon catheter; Figure 7 Figure 5 ​​Side view of sequential inflation balloon catheter;

[0025] Figure 8 is Figure 5 Side view of sequential inflation balloon catheter;

[0026] Figure 9 is Figure 5 Side view of sequential inflation balloon catheter;

[0027] Figure 10 is Figure 5 Side view of sequential inflation balloon catheter;

[0028] Figure 11 is side view of balloon catheter with enlarged guidewire channel;

[0029] Figure 12 is Figure 11 Side view of balloon catheter;

[0030] Figure 13 is Figure 11 Side view of balloon catheter;

[0031] Figure 14 is side view of balloon catheter;

[0032] Figure 15 is side view of balloon catheter with guide catheter and occlusion catheter; Figure 14 Side view of balloon catheter in DETAILED DESCRIPTION

[0033] Specific embodiments of the present application will now be described with reference to the accompanying drawings. However, the present application can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art. The terminology used in the detailed description of the embodiments illustrated in the accompanying drawings is not intended to be limiting of the present application. In the drawings, like numbers refer to like elements throughout. While different embodiments are described in detail, features of each embodiment can be interchanged and used in other embodiments. In other words, any feature of each embodiment can be mixed and matched with features of other embodiments, and embodiments need not be strictly construed as including only the features shown or described.

[0034] While the terms "drug" and "drug coating" are used in this specification, these terms are intended to include any therapeutic agent, compound, chemical, or other material that can be incorporated into a device coating.

[0035] As previously mentioned, during a treatment procedure, drug coated devices (such as balloon catheters and stents) typically release an undesirable amount of drug coating into the blood, which then circulates through the patient's vascular system. Much of the unwanted drug release can occur when the device (such as a balloon or stent) is tracked through an outer guide catheter, during expansion of the device within the patient's blood vessel, during deflation of the device, and during retraction of the catheter.

[0036] In Figure 1 and Figure 2 one specific example of this undesirable drug coating loss can be seen. Figure 1 A typical balloon catheter 100 is shown having a drug coated balloon 106 at the distal end of an elongated catheter body 102. The catheter body 102 also includes a guidewire passage 104 opening proximal and distal of 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 allow balloon inflation. While this guidewire passage 104 configuration is generally referred to as a rapid exchange catheter type, over-the-wire style catheters that include a guidewire passage opening at the proximal end of the catheter can also be considered.

[0037] Referring to Figure 2 , the balloon catheter 100 is typically advanced out of an overlying guide catheter 110 so that the drug coated balloon 106 is positioned adjacent to the blood vessel wall of the target treatment area. An inflation medium is injected into the inflation lumen to inflate the drug coated balloon 106 and contact the blood vessel wall, with at least some of the drug coating being delivered to the blood vessel wall. Finally, the drug coated balloon 106 is deflated and retracted into the overlying guide catheter 110. Note that while guide catheters are used in this description, it should be understood that guide sheaths or introducer sheaths can alternatively be used as this component in this description.

[0038] As Figure 2 shown, during this treatment procedure, much of the drug coating 109 is released from the balloon 106, where it mixes with the patient's blood and circulates through at least a portion of the patient's vascular system and organs (such as the heart and lungs). Depending on the drug type, the amount released from the balloon, the treatment location, and other factors, significant and undesirable concentrations of the drug can remain in the patient's blood and / or organs for days or even weeks after the treatment procedure.

[0039] This specification describes several therapeutic devices and methods for reducing unwanted accumulation of medication removed from the coating of a therapeutic device. While different embodiments of balloon catheters are described primarily, it should be understood that these devices and methods can be similarly adapted for use with other drug-coated devices, such as stents, or even uncoated devices that deliver medication directly to a target area (e.g., exudative balloons configured to drain medication from their orifices).

[0040] Figure 3 and Figure 4 One embodiment of a treatment system 120 is shown, configured to aspirate or remove at least some of the drug coating released into a patient's vascular system during treatment. The treatment system 120 includes a balloon catheter 121 having an occlusion balloon 124 configured to occlude the distal portion of a target blood vessel in the patient before inflation of a drug-coated balloon 126. As discussed in detail below, during the procedure, blood containing any free or released drug coating is aspirated and removed from the patient to prevent circulation through the patient's blood vessels.

[0041] The occlusion balloon 124 is located distal to the drug-coated balloon 126 on the elongated body 122 of the balloon catheter 121. Balloons 124 and 126, along with the elongated body 122, are configured to allow the occlusion balloon 124 to be fully inflated before significant inflation of the drug-coated balloon 126, and to allow the occlusion balloon 124 to deflate after the drug-coated balloon 126 deflates. This inflation sequence helps maintain vascular occlusion during the portion of the process in which the drug coating is most likely to migrate into the patient's bloodstream; therefore, the occlusion balloon 124 helps prevent drug migration distally from the drug-coated balloon 126, and / or, as will be explained in more detail, helps provide a seal for subsequent aspiration procedures. In one example, this inflation sequence can be achieved via two separate inflation lumens within the elongated body 122, each inflation lumen connected to a separate inflation lumen and inflation port (e.g., ports 123A and 123B) at the proximal end of the elongated body 122.

[0042] In another example, balloon 124 and balloon 126 can be connected to a single inflation lumen in body 122. To create the desired inflation sequence, occlusion balloon 124 can be constructed of a material that inflates more easily than drug-coated balloon 126. In one specific example, occlusion balloon 124 can be constructed of a relatively inelastic material that increases in diameter with little resistance (e.g., similar to inflating a plastic bag), while drug-coated balloon 126 can be constructed of a relatively elastic material that stretches to provide resistance during inflation (e.g., similar to a rubber party balloon). Thus, as pressure in the inflation lumen is increased, occlusion balloon 124 inflates first, drug-coated balloon 126 inflates second, drug-coated balloon 126 deflates first, and occlusion balloon 126 deflates last.

[0043] In any of the above balloon inflation examples, the proximal end of elongate body 122 (e.g., a catheter hub) can be connected to one or more manually driven syringes to cause inflation or to a motorized inflation device. In the case of a motorized inflation device, it can be necessary to provide and maintain various pressure levels within the inflation lumen and balloons, especially in the single inflation lumen example described above, as these different pressure levels within the inflation lumen dictate the inflation sequence of balloons 124 and 126 (e.g., low pressure can only inflate occlusion balloon 124, while high pressure inflates both drug-coated balloon 126). In this regard, the motorized inflation device can include an algorithm configured to provide a predetermined sequence of pressure levels to achieve the desired balloon inflation and deflation sequence.

[0044] As described above, treatment system 120 is also configured to provide aspiration to remove any blood in the vicinity of the drug-coated balloon that contains any drug coating 128 that has been removed. In the present example, this aspiration can be provided through a sheath that is positioned through external guide catheter 130 or balloon catheter 121. Guide catheter 130 can have a generally tubular body and can include an aspiration port 132 that leads to the lumen of guide catheter 130, allowing a vacuum source (e.g., syringe 136 or a pump) to be connected thereto. When the vacuum source is activated, it causes blood from the distal end of guide catheter 130 to be pulled into its lumen and toward the vacuum source. Since guide catheters typically include a hemostatic valve on their proximal end (e.g., around balloon catheter 121), air is prevented from being drawn into the lumen of guide catheter 130. In other words, guide catheter 130 is configured to only allow aspiration from its distal end toward the vacuum source and not from the proximal end of guide catheter 130. In the present example, the continued occlusion of the blood vessel helps to prevent the removed drug particles from moving through the patient's vasculature before guide catheter 130 is able to aspirate them out of the patient.

[0045] In the case where the syringe 136 is used as a vacuum source, the physician can initially hold the stopcock valve 134 located between the syringe 136 and the guide catheter 130 in a closed position. The plunger of the syringe 136 can be withdrawn to create a vacuum pressure, and then the stopcock valve 134 can be opened when aspiration is desired within the patient. Blood from the area near the drug-coated catheter 126 is then drawn into the guide catheter 130 and further into the syringe 136. Depending on the location of the procedure, the nature of the drug coating, and other factors, different amounts of blood can be aspirated. In many cases, a 30 cc or 60 cc syringe or aspiration volume can be appropriate.

[0046] In one example, the treatment system 120 can be used by first advancing a guide wire through the patient's vasculature so that its distal end is located near a desired treatment location within a blood vessel. Next, the guide catheter 130 can be advanced over the guide wire so that its distal end is located near the desired treatment location. The balloon catheter 121 is then advanced over the guide wire through its guide wire channel 122A so as to position the drug-coated catheter 126 at the desired target location and to position the occlusion balloon 124 distal of the target location. Optionally, the guide wire can be withdrawn prior to inflation of the balloon 124 and the balloon 126.

[0047] Next, the occlusion balloon 124 is inflated so that it occludes the blood vessel and substantially prevents blood flow through the blood vessel. Once the blood vessel is occluded, the drug-coated balloon 126 is inflated so that the drug coating 128 on the balloon 126 contacts the inner surface of the blood vessel, delivering or otherwise transferring its drug coating to the blood vessel tissue, as shown. Figure 3

[0048] As previously mentioned, a substantial portion of the drug coating 128 can be removed or released through the process of tracking the balloon catheter 121 through the guide catheter 130, inflating the drug-coated balloon 126, deflating the drug-coated balloon 126, and other movements during the process. In this regard, the physician can perform aspiration through the guide catheter 130 when the drug-coated balloon 126 is deflated (partially or completely). However, aspiration can also be applied throughout the tracking and inflation process, among other techniques. Moreover, this aspiration can be generated through the opening of the valve 134 connected to the syringe 136 having a retracting plunger, among other techniques.

[0049] As Figure 4 ​As shown, blood and the removed drug coating 128 are drawn into the guiding catheter 130, the outflow port 132, and the syringe 136 (although some blood and coating may remain in the guiding catheter 130). In one example, a physician may remove 30 to 60 milliliters of blood from the area 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 already fully deflated), and the occlusion balloon 124 is also fully deflated, allowing the physician to withdraw the balloon catheter 121 proximally back into the guiding catheter 130 to complete the procedure. Thus, much of the removed drug coating that would otherwise circulate in the patient's vascular system is removed from the patient.

[0050] Figures 5-10 Another embodiment of a balloon catheter 140 is shown, which has a single sequentially inflatable balloon 146 that can be partially inflated first to occlude a portion of a patient's blood vessel, and then fully inflated to deliver a therapeutic agent to the vascular tissue. Similar to the previously described balloon catheter 121, this allows for occlusion of a portion of a patient's blood vessel to prevent the migration of displaced medication, followed by aspiration to remove any displaced medication from the patient's bloodstream.

[0051] like Figure 5 and Figure 6 As shown, the balloon catheter 140 includes an elongated body 142 and a balloon 146. The elongated body 142 has a guidewire channel 144 (e.g., a quick-exchange, single-rail guidewire channel) extending through at least its distal portion, and the balloon 146 is disposed near the distal end of the elongated body 142.

[0052] The drug coating is positioned on the proximal balloon portion 146B to enable drug delivery to the patient's blood vessel, while the distal balloon portion 146A has virtually no drug coating. Therefore, the distal balloon portion 146A can expand to occlude the vessel, and if any, the drug coating on this portion is rarely displaced and moves distally to the catheter 140.

[0053] like Figures 7-10 As shown, the balloon catheter 140 is configured to sequentially inflate and deflate the distal balloon portion 146A and the proximal balloon portion 146B. Specifically, the distal balloon portion 146A is inflated first, followed by the proximal balloon portion 145B; the distal balloon portion 146A is deflated, and then the proximal portion 145B is deflated.

[0054] This sequential balloon inflation can be achieved through several different techniques. For example, each portion 146A, 146B of balloon 146 can be composed of a material that allows the distal balloon portion 146A to inflate at a lower pressure (i.e., is more easily inflated) than the proximal balloon portion 146B. This difference in resistance to inflation between the two portions 146A, 146B can be achieved through portions of different materials, different material thicknesses, additional layers / bands of material on the proximal portion 146B, any combination of these techniques, or similar techniques. Elongate body 142 can also include a single inflation lumen in communication with balloon 146 to allow for the inflation / deflation sequence. As with the previous embodiment, the inflation mechanism can be a manually driven device, such as a syringe, or a motorized inflation device, which can be programmed to achieve and maintain the specific, desired pressures required for the inflation sequence.

[0055] In another example, balloon 146 can include a mechanism to deliver and draw inflation media to the distal balloon portion 146A and the proximal balloon portion 146B at different rates to cause sequential inflation. This can be achieved through larger distal inflation ports and smaller proximal inflation ports on elongate body 142 beneath balloon 146, portions of the balloon 146 that are partially or fully walled that separate portions 146A, 146B, distal and proximal inflation ports with valves that have different opening amounts, separate inflation lumens within elongate body 142, or a combination of these features.

[0056] Balloon catheter 140 can be used in the following example procedure. First, a guidewire is advanced within a patient such that its distal end is located near a target region of a patient's blood vessel. Next, an elongate, tubular guide catheter 148 is advanced over the guidewire such that the distal end of guide catheter 148 is located near the target region. Next, balloon catheter 140 is advanced over the guidewire and through the lumen of guide catheter 148 such that its distal end and balloon 146 are located at the target region of the patient's blood vessel. Preferably, distal portion 146A is located distal to the target region, while the proximal portion 146B of the drug coating is positioned circumferentially within the target region of the blood vessel.

[0057] Referring to Figure 7 , the distal portion 146A of balloon 146 is initially inflated to cause it to fully or substantially occlude the blood vessel. As shown in Figure 8 , the proximal portion 146B of the drug coating is inflated, causing its drug coating surface to expand relative to the target region of the blood vessel to deliver or transport a portion of its drug.

[0058] Referring to Figure 9The proximal balloon portion 146B is partially or completely deflated, leaving any dislodged drug coating 143 trapped in the blood captured near the balloon 146. At this point, aspiration is performed through the guide catheter 148, but can also be performed prior to this. This aspiration can be applied in a similar manner and using similar devices as described previously for the guide catheter 130.

[0059] Finally, as shown in FIG. 16C, the balloon 146 can be fully inflated and retracted into the guide catheter 148, such that the procedure can be completed. During this full deflation and balloon retraction, aspiration can optionally continue to further remove any drug coating that can be dislodged. Figure 10

[0060] Figures 11-13 Another embodiment of a balloon catheter 150 is shown, configured to allow aspiration through its distal end to assist in removing the partially dislodged drug coating 156. This distal aspiration can optionally be used in conjunction with proximal aspiration from the balloon 154 of a guide catheter, such as the previously described guide catheters 130 and 148.

[0061] The balloon catheter 150 can include an elongated body having a guidewire channel extending through the body, which is also configured to function as an aspiration channel. The channel can have a proximal opening 157 in the hub 151 of the catheter that allows the guidewire to enter the channel, and a distal opening 158 that allows the guidewire to exit the channel. The catheter hub 151 can have an aspiration port 153 that is also in communication with the guidewire channel, and can be connected to a vacuum source, such as the syringe 136. A hemodynamic valve in the proximal portion of the guidewire channel seals the proximal end of the channel, so that when vacuum pressure is applied to the guidewire channel, it causes aspiration or suction out of the distal opening 158 of the balloon catheter 150.

[0062] Optionally, the diameter of the guidewire channel is slightly larger than a typical guidewire channel to prevent clogging during aspiration, and to ensure that aspiration is able to clear blood at the desired rate. In one example, the ratio of the guidewire / aspiration channel to the inflated balloon 154 diameter is in a range that includes about 0.2 to 0.8. Some example ratios and measurements for prior art guidewire catheter lumens and larger guidewire channel sizes according to the present embodiment are shown in Table 1. For example, a ratio of a guidewire lumen diameter size of 0.36 mm and a balloon diameter size of 2 mm is 0.18, while a ratio of a balloon diameter of 1.22 mm and a balloon diameter of 2 mm is 0.61.

[0063] Table 1

[0064]

[0065] ​Balloon catheter 150 can be used in the following example procedure. First, a guidewire is advanced within a patient's body with its distal end located near a target region of a patient's blood vessel. Next, an elongate, tubular guide catheter (similar to guide catheter 130 or guide catheter 148) is advanced over the guidewire so that the distal end of the guide catheter is located near the target region. Next, balloon catheter 150 is advanced over the guidewire and through the lumen of the guide catheter so that its distal end and balloon 154 are located at the target region of the patient's blood vessel.

[0066] Referring to Figure 12 Balloon 154 is inflated so that its drug coating 156 is pressed against the tissue of the target region. As balloon 154 is deflated from the guide catheter and inflated, suction can be applied from the guide catheter (as described in previous embodiments) and / or from distal opening 158 of the guidewire lumen to help collect any loose drug coating 156 that is dislodged during this period.

[0067] Referring to Figure 13 Balloon 154 can be deflated after the desired amount of time in contact with the target region. As this deflation can cause further drug coating to be dislodged (shown as element 159 in the blood), further suction helps to capture and draw away the drug particles and blood from the distal end of catheter 150. Suction according to this embodiment can only be applied through distal opening 158 at different times throughout the procedure, or in combination with suction from the guide catheter.

[0068] When suction is applied from distal opening 158 and the guide catheter, different vacuum pressures can need to be applied from each source depending on the power of suction intended. For example, a lower, gentler vacuum pressure can be needed from distal opening 158 to prevent collapse of the patient's blood vessel, while a relatively stronger vacuum source from the guide catheter can counteract collapse of the blood vessel due to the balloon catheter extending distally outward from the guide catheter opening.

[0069] Figure 14 and 15 Another embodiment of a treatment system is shown that allows for proximal and distal selective suction of a drug-coated balloon 162 during a procedure. Specifically, the configuration of drug-coated balloon catheter 160 enables it to couple or sealingly engage with the distal opening of guide catheter 130 that is connected to a suction source. As shown in Figure 15 This arrangement allows guide catheter 130 to suction from the proximal end of balloon 162 when uncoupled from balloon 162, or to suction from the distal end of balloon 162 through channel 164 when coupled with the proximal end of balloon 162.

[0070] In one embodiment, the drug-coated balloon catheter 160 includes an elongated catheter body 168 connected at its distal end to an enlarged tubular portion having a passageway 164. A balloon 164 is connected on the enlarged tubular portion and is configured to be inflated through an inflation lumen within the elongated catheter body 168.

[0071] The balloon 162 is configured to be inflated such that the distal balloon portion 162A has a larger inflated diameter, while the proximal balloon portion 162B has a relatively smaller inflated diameter. The inflated diameter of the distal balloon portion 162A is preferably large enough to contact the inner diameter of the target blood vessel, thereby allowing it to deliver some of the drug coating 166. The inflated diameter of the proximal balloon portion 162B has a diameter that is about the size of the inner lumen of the guide catheter 130 (e.g., slightly larger than, equal to, or slightly smaller than the inner lumen). This size allows the inflated proximal balloon portion 162B to fit within and engage the interior of the guide catheter 130. Thus, when suction is applied to the guide catheter 130, it continues through the proximal opening 164A of the passageway 164 and out the distal opening 164B. Optionally, the proximal balloon portion 162B can be inflated to a conical or ramped shape that increases in the distal direction so that it can "wedge" into the inner lumen of the guide catheter 130.

[0072] Optionally, the passageway 164 has a diameter large enough to accommodate a crossing balloon catheter 170 therethrough to allow for occlusion of the blood vessel region distal of the occlusion balloon 162, similar to the previous embodiment. In one example, the passageway 164 can have a diameter that accommodates the balloon 174, thus having an inner diameter of about 0.050". In this regard, the diameter of the passageway 164 can provide a substantial amount of clearance around the body 172 of the balloon catheter 170 so that suction can be provided through the passageway 164 when the balloon catheter 170 is also located within the passageway 164.

[0073] The balloon catheter 160 can be used in the following example procedure. First, the guidewire 111 is advanced within the patient so that its distal end is located near the target region of the patient's blood vessel. Next, the elongated tubular guide catheter 130 is advanced over the guidewire 111 so that the distal end of the guide catheter 130 is located near the target region. Next, the drug-coated balloon catheter 160 is advanced over the guidewire (through the passageway 164) and through the inner lumen of the guide catheter 130 so that its distal end and balloon 162 are located at the target region of the patient's blood vessel.

[0074] Optionally, the occlusion balloon catheter 170 is advanced over the guidewire 111 and through the passageway 164 of the drug-coated balloon catheter 160. The occlusion balloon 174 is then inflated to contact and occlude the region of the patient's blood vessel distal of the target region. This arrangement is shown in FIG. 17. Figure 15 .

[0075] Next, the balloon 162 of the drug-coated catheter 160 is inflated so that the drug coating 166 on the distal balloon portion 162A contacts the target area of the patient's blood vessel. During this time, the distal end of the guide catheter 130 can be positioned in close proximity to the balloon 162 and suction can be applied in the manner previously discussed in other embodiments.

[0076] The distal end of the guide catheter 130 can then be moved distally of the balloon 162 so that its lumen encompasses and overlaps the smaller diameter portion 162B of the balloon 162. Suction through the guide catheter 130 is then activated, if it has not already been activated, creating suction in the space between the occlusion balloon 174 (if present) and the drug-coated balloon 162. As a result, any dislodged drug coating in the blood located between the two balloons 162, 174 is partially or completely removed.

[0077] Once the desired amount of suction has occurred, the drug-coated balloon 162 is deflated and withdrawn into the guide catheter 130. Similarly, the occlusion balloon 174 is deflated and withdrawn into the guide catheter 130, and the procedure can be completed.

[0078] In alternative embodiments, any of the drug-coated balloons and / or occlusion balloons of the previously described embodiments can be replaced with non-inflatable devices, such as an expandable mesh device.

[0079] In alternative embodiments, the drug-coated balloons and balloon catheters of the previously described embodiments can be replaced with drug-coated stents (or similar implantable devices) and stent delivery catheters.

[0080] In another embodiment, the drug-coated balloons and balloon catheters of the previously described embodiments can be replaced with balloon catheters having a balloon that is capable of "bleeding" or slowly releasing a liquid drug from pores in its balloon surface.

[0081] The procedures described in this embodiment can be performed at many different locations within a patient's vascular system, but can be particularly useful for procedures on the arms, legs, and torso.

[0082] While the application has been described in terms of particular embodiments and applications, those skilled in the art will recognize that additional embodiments and modifications are within the spirit and scope of the claimed application. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive.

Claims

1. A vascular treatment system comprising: a balloon catheter comprising: an elongated body; a drug coated balloon connected proximate a distal end of the elongated body; a drug coating disposed on the drug coated balloon; and an enlarged tubular portion connected at the distal end of the elongated body; a guide catheter comprising: an elongated tubular body having an internal guide catheter lumen; and an aspiration port connected to the guide catheter lumen and further configured to be connected to a vacuum source; wherein the guide catheter is configured to aspirate blood proximate the drug coated balloon during a treatment procedure; wherein the balloon catheter has a first aspiration position in which a proximal portion of the drug coated balloon is sealingly engaged with a distal opening of the internal guide catheter lumen to aspirate distally from the drug coated balloon through the enlarged tubular portion; and, wherein the balloon catheter has a second aspiration position in which the proximal portion of the drug coated balloon is disengaged from the distal opening of the internal guide catheter lumen to aspirate proximally from the drug coated balloon.

2. The vascular treatment system of claim 1, wherein the balloon catheter further comprises an occlusion balloon connected distal of the drug-coated balloon on the elongate body; wherein, During inflation of the balloon catheter, the occlusion balloon expands from a first deflated configuration to a first inflated configuration prior to inflation of the drug coated balloon.

3. The vascular treatment system of claim 2, wherein, During deflation of the balloon catheter, the drug coated balloon deflates from a second inflated configuration to a second deflated configuration prior to deflation of the occlusion balloon.

4. The vascular treatment system of claim 1, wherein the drug coated balloon comprises: a distal portion; and a proximal portion; wherein the drug coating is disposed on the proximal portion and wherein the drug coated balloon inflates the distal portion first and then inflates the proximal portion.

5. The vascular treatment system of claim 4, wherein the distal portion is configured to inflate prior to the proximal portion by one or more of the following features: a different balloon thickness, a reinforcing band, using a different balloon material between the proximal and distal portions, and using a different inflation pore size between the proximal and distal portions.

6. The vascular treatment system of claim 4, wherein the balloon catheter comprises a guide wire channel opening distal of the drug coated balloon and is configured to be connected to an aspiration source and provide aspiration at the guide wire channel opening.

7. The vascular treatment system of claim 1, wherein the balloon catheter comprises a guide wire channel opening distal of the drug coated balloon and is configured to be connected to an aspiration source and provide aspiration at the guide wire channel opening.

8. The vascular treatment system of claim 7, wherein a ratio between a diameter of the inflated drug coated balloon and a diameter of the guide wire channel opening is in a range comprising 0.2 to 0.

8.

9. The vascular treatment system of claim 1, wherein the drug coated balloon has a distal portion with a drug coating disposed thereon and a proximal portion with a full inflated diameter sized to fit into and engage with an internal catheter lumen.

10. The vascular treatment system of claim 9, further comprising an occlusion catheter configured to be advanced distally through the passageway of the balloon catheter and to occlude the vessel distal of the drug coated balloon.

11. The vascular treatment system of claim 10, wherein the proximal end of the drug coated balloon has a tapered or beveled shape such that it can wedge into the interior of the guide catheter.

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