Intravascular administration device

Abstract

This invention provides a drug infusion catheter (100) comprising an axially extending elongated member (101), an inflatable balloon (121), and two or more cannulas (122), each cannulas containing a retractable needle (123). When the balloon (121) is inflated, the distal portion of the cannulas (122) does not extend beyond the outermost diameter of the inflatable balloon (121). This drug infusion catheter (100) facilitates the delivery of drugs to lumen or perivascular tissue within the body.

Description

Technical Field

[0001] The present invention relates to a device, namely a catheter (e.g., a quick-exchange catheter or an over-the-wire catheter), for delivering drugs into the body, particularly into physiological cavities or tissues surrounding blood vessels. Background Technology

[0002] Various methods can be used to deliver drugs into the body, including oral, submucosal, parenteral, and transdermal administration. However, these methods are often affected by nonspecific delivery, leading to potential off-target side effects. Since dosing efficiency is crucial in disease treatment, concentrated administration can improve efficacy and reduce side effects.

[0003] The technique of delivering drugs almost entirely to the desired site is called smart drug delivery. Smart drug delivery improves the bioavailability of drugs at the disease site, thereby reducing the frequency of dosing and minimizing the side effects of systemic administration. Smart drug delivery can be achieved through many possible methods, such as using nanoparticle carriers with strong affinity for specific proteins to control the final location of the therapeutic agent. However, a drawback of this approach is that the target site needs to be sufficiently distinct from other locations by the nanoparticle carrier. This means that the method is not applicable in all situations.

[0004] Injecting the therapeutic agent directly into the treatment area is one of the simplest methods for controlling the delivery of the agent. However, this method becomes difficult when the target site is hard to reach. During injection, the needle is typically inserted from outside the body, penetrating the skin and other tissues until the needle tip reaches the target site. The therapeutic agent is then injected directly into the target body using the needle. The main limiting factor of this method is whether the needle can reach the target site. This method cannot reach certain areas, such as areas covered by bone. Another drawback of this method is that the needle must penetrate a significant portion of the patient's tissue to reach the target site, making it difficult to achieve high precision.

[0005] When the target is located deep within body tissue, this method can be improved by guiding the needle device through the vascular network to reach the target vessel before the needle extends and pierces the target vessel to the target site. Since blood vessels are located in almost every area of ​​the body, the vessel wall is a primary target for smart drug delivery. Directly injecting therapeutic agents circumferentially into the vessel wall can effectively treat some diseases, such as vascular diseases, arterial restenosis, and promoting angiogenesis in ischemic hearts. This delivery method can also be used with neuroablation agents to achieve neuroablation. Diseases that can be treated by ablating nerves around blood vessels include hypertension and diabetes, with the renal artery and hepatic artery being the target vessels for denervation.

[0006] Certain intravascular injection devices have been disclosed in the prior art, and these will be discussed below.

[0007] The descriptions in U.S. Patent Nos. 6,547,803 and 7,666,163 by Seward et al. The microinfusion catheter comprises a single needle connected to an inflatable elastic balloon. When the inflatable balloon inflates within the blood vessel, it forces the needle to compress the vessel wall, thereby penetrating the inner wall. The needle can then be used to inject therapeutic agents or neuroablatives. Seward et al. also described an embodiment using two needles, but such a system would be difficult to miniaturize and reach smaller blood vessels. Although Microinfusion catheters can deliver therapeutic agents or neuroablation agents to target vessels, but their use in the treatment of vascular diseases and ablation therapy has some limitations. First, if only a single needle is used, multiple administrations are required to achieve circumferential delivery within the target vessel. Even then, controlling precise rotation of the distal end of any device through proximal manipulation is difficult, potentially leading to irregularly spaced injections. Second, Micro-infusion catheters rely on balloon inflation, thus preventing the achievement of precise, controllable, and adjustable penetration depths. Third, the achievable maximum penetration depth is limited. The maximum penetration depth depends on the needle length, but the maximum needle length is finite because excessive length would affect the device's profile. Therefore, the inability to inject medication to a sufficient depth limits the therapeutic capabilities of the device.

[0008] U.S. Patent No. 6,692,466 to Chow et al. and U.S. Patent No. 7,273,469 to Chan et al. disclose a catheter containing a retractable needle within a guide tube for injecting drugs into tissue. The distal portion of the guide tube is attached to a portion of an inflatable element, while the proximal portion is adhered to a tubular element connected to the inflatable element. While this device enables precise, controlled, and adjustable circumferential delivery, it also has several drawbacks. First, because the guide tube must follow the contours of the balloon, securing it to the balloon and tubular element limits its bending range. Abrupt changes in the guide tube's orientation result in a smaller bending radius, increasing the force required to remove the needle from the curvature. This increased force increases the likelihood of needle damage or puncture of the guide tube. Second, the material used for the guide tube is limited. Due to the small bending radius, the material used for the guide tube must be flexible. Chan et al. mentioned using a sheath ring to prevent guide tube detachment; however, even with this structure, the guide tube still needs to be flexible. This requirement for the guide tube limits the material to polymers, prohibiting the use of metals and alloys. Third, achieving a large penetration depth to needle advance ratio is difficult with this device. The optimal penetration depth to needle advance ratio is 1:1, achievable only when the needle is perpendicular to the catheter axis. In this device, this ratio is determined by the balloon cone angle, typically between 20 and 40 degrees. One way to increase this ratio without changing the balloon cone angle is to use a distally curved needle. However, since Chow and Chan could not use rigid materials for the catheter, curved needles could not be used. Furthermore, Chow and Chan mentioned using a rigid strip / deflector to prevent puncture at bends, but a curved needle would keep the needle tip opposite the guide tube throughout its travel length, making the use of a strip / deflector on a curved needle impractical.

[0009] The Peregrine system described in U.S. Patent No. 8,740,849 to Fischell et al. TM (PeregrineSystem TM Using three equally spaced guide needle elements, the guide needle elements are moved outward to the center of the catheter before the needle tip unfolds from within each element. Neuroablation agents can then be used to achieve circumferential ablation of the target vessel through these needles. Although the Peregrine system... TM (Peregrine System TM While capable of precise, controllable, and adjustable depth delivery, the Peregrine system still has some limitations when using guide needle elements to position the catheter within the target vessel. Firstly, the Peregrine system within the target vessel... TM (Peregrine System TMDuring the centering process, the guide needle elements extend simultaneously at the same speed until all elements are in contact with the inner wall of the target vessel. This centering method is suitable for round vessels such as arteries, but for vessels with irregular or flat cross-sectional shapes such as veins, it cannot achieve circumferential drug deposition within the vessel. If the target vessel is forced into a round shape using guide needle elements, there is a risk of serious damage to the vessel due to the small contact area provided by the guide needle elements. Second, the high pressure that may be generated between the contact point of the hollow guide needle element and the vessel wall poses a risk of damage to the vessel wall. Third, there is a risk that the catheter needs to be repositioned after the guide needle elements extend. Unless the pressure between the guide needle element and the vessel wall is very high, the small number of contact points between the guide needle element and the vessel wall may not provide sufficient stability for the catheter. If the proximal end of the catheter is accidentally moved, it may cause displacement of the distal end of the catheter. If this occurs before the needle is extended, simple repositioning is sufficient. However, if this occurs after the needle is extended, it can cause serious damage to the vessel. Fourth, it is difficult to achieve the same penetration depth for all needles. All contact points provided by the guide needle elements are in a single plane. Due to the Peregrine system TM (Peregrine System TM The guide element and needle tip of the [system name] have a preset curved shape, and the contact plane must be perpendicular to the target blood vessel to ensure that all needles achieve the same penetration depth within the target blood vessel. If precise drug delivery to a specific depth is required, then the Peregrine system should be used. TM (Peregrine System TM Achieving the required precision at all injection points will be a challenge.

[0010] Therefore, there is an urgent need for an infusion catheter to overcome the problems of the existing technology. Summary of the Invention

[0011] This invention provides a catheter for delivering substances to tissues outside physiological cavities. This catheter can be used to deliver therapeutic agents to prevent and / or treat a variety of diseases, such as vascular diseases, arterial restenosis, ischemic heart disease, and diseases requiring neuroablation, such as hypertension, diabetes, or chronic obstructive pulmonary disease.

[0012] Therefore, the present invention provides the following solution.

[0013] A drug delivery device, comprising:

[0014] An axially extending elongated member having a proximal portion, a distal portion, a first lumen, and a second lumen;

[0015] An inflatable balloon is connected to the distal portion of the axially extending elongated member, the inflatable balloon having a proximal end and a distal end connected by a working portion, the inflatable balloon also having an outer surface and an inner surface defining a balloon cavity, wherein a first lumen of the axially extending elongated member is in fluid communication with the balloon cavity.

[0016] Two or more guide sleeves, each guide sleeve having a proximal portion and a distal portion, wherein the proximal portion of each guide sleeve is connected to the axially extending elongated member; and

[0017] Two or more needles, each needle having a lumen and being housed in one of the guide sleeves, each needle being reversibly telescoping from the distal portion of the guide sleeve housing itself, wherein the second lumen of the axially extending elongated member is in fluid communication with the lumen of each needle.

[0018] Wherein, when the inflatable balloon is inflated, the distal portion of each of the guide sleeves does not exceed the outermost diameter of the outer surface of the inflatable balloon.

[0019] Preferably, the inflatable balloon is connected to the distal end of the axially extending elongated member.

[0020] Preferably, it also includes a balloon support element located within the inflatable balloon, optionally connected to the distal portion of the axially extending elongated member and the distal end of the inflatable balloon, respectively.

[0021] Preferably, the axially extending elongated member includes a third lumen, which is optionally adapted to mount the drug delivery device on a guidewire.

[0022] Preferably, the inflatable balloon is disposed on the distal portion of the axially extending elongated member.

[0023] Preferably, the distal portion of each of the guide sleeves is freely movable relative to the inflatable balloon, and / or the distal portion of each of the guide sleeves is not fixed to the inflatable balloon.

[0024] Preferably, the guide sleeve is arranged at uniform intervals around the outer periphery of the axially extending elongated member.

[0025] Preferably, the distal portion of the guide sleeve is configured to contact the outer surface of the inflatable balloon and move with the outer surface of the inflatable balloon as the balloon is inflated.

[0026] Preferably, the guide sleeve is configured to at least partially return to its original shape when the inflatable balloon deflates.

[0027] Preferably, the inflatable balloon has a proximal cone, a middle cylindrical portion, and a distal cone.

[0028] Preferably, the distal portion of the guide sleeve is configured to contact the outer surface of the proximal cone of the inflatable balloon.

[0029] Preferably, each of the guide sleeves includes a slit formed by cutting one side of the guide sleeve.

[0030] Preferably, the guide sleeve is made of metal or alloy.

[0031] Preferably, it also includes a sheath movably disposed on the axially extending elongated member.

[0032] Preferably, the sheath has an extended state and a retracted state. In the extended state, the sheath covers the entirety of the two or more guide sleeves and at least a portion of the inflatable balloon. In the retracted state, the sheath does not cover a portion of the inflatable balloon. Optionally, in the retracted state, the sheath covers only a portion of the two or more guide sleeves.

[0033] Preferably, the needle can simultaneously and reversibly extend and retract.

[0034] Preferably, the needle can extend and retract independently and reversibly.

[0035] Preferably, each of the needles includes a bent end, and optionally, each of the needles is configured such that when the needle extends from the guide sleeve containing itself, the bent end bends radially outward from the axially extending elongated member.

[0036] Preferably, the second lumen of the axially extending elongated member includes two or more sub-lumens, each of which is fluidly connected to the lumen of the needle. Optionally, the two or more sub-lumens are not fluidly connected to each other.

[0037] Preferably, it also includes a support structure for positioning the guide sleeve and securing the guide sleeve to the axially extending elongated member.

[0038] Preferably, the distal end of the axially extending elongated member is connected to a flexible tip.

[0039] Preferably, the drug delivery device is a rapid-exchange catheter or an integral-exchange catheter.

[0040] Preferably, it includes at least one radiopaque element, optionally located within the balloon cavity, or on the axially extending elongated member, or on the guide sleeve, and / or on the needle.

[0041] Preferably, it also includes a handle disposed at the proximal end of the axially extending elongated member.

[0042] Preferably, the handle includes a structure for controlling the maximum extension depth of the needle.

[0043] Preferably, the handle includes means for reversibly extending and retracting the needle from the guide sleeve.

[0044] Preferably, the device includes a first means for coarsely reversibly extending and retracting the needle and a second means for finely reversibly extending and retracting the needle.

[0045] Preferably, the handle includes a visual indicator that indicates the depth of needle extension.

[0046] Preferably, the guide sleeve includes a bend at the distal end; optionally, each guide sleeve has an opening at the distal end that extends outward from the conduit.

[0047] Better place,

[0048] Each of the needles includes a bent end;

[0049] The distal portion of the guide sleeve is configured to contact the outer surface of the inflatable balloon and move with the outer surface of the inflatable balloon; and

[0050] After the inflatable balloon is deflated, the guide sleeve at least partially returns to its original shape.

[0051] Optionally, each of the needles is configured such that when the needle extends from the guide sleeve containing itself, the bent end bends radially outward from the axially extending elongated member.

[0052] Compared to the previously described device, the present invention has several advantages. By using a retractable needle, the device can achieve a greater range of penetration depths in a controlled manner. This is similar to the Peregrine system described in U.S. Patent No. 8,740,849 to Fischell et al. TM (Peregrine System TM Compared to catheters, using a balloon instead of a catheter to center and stabilize the device provides better stability because an inflatable balloon anchors the device better. Since the surface area of ​​the balloon in contact with the lumen is much larger than with a catheter, using a balloon reduces the pressure applied to the lumen wall, thus lowering the risk of damage. The use of a balloon also makes the device suitable for non-circular vessels, as is the case with the Peregrine system. TM (Peregrine System TMThe use of a guide needle element for centering the blood vessel makes it unsuitable for non-circular vessels. Many veins are indeed non-circular, and using a catheter to center and stabilize the device in such vessels is not optimal because the catheter would apply excessive pressure to certain points on the vessel wall. The balloon of this invention, however, forces the vessel into a circular shape for optimal therapeutic effect, thus making it suitable for such non-circular vessels. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of the first embodiment of the present invention, wherein the sheath is in the extended position.

[0054] Figure 2 This is a schematic diagram of the first embodiment of the present invention, wherein the sheath is in the retracted position, the balloon is in the deflated state, and the needle is in the retracted position.

[0055] Figure 3 This is a schematic diagram of the first embodiment of the present invention, wherein the sheath is in the retracted position, the balloon is in the inflated state, and the needle is in the retracted position.

[0056] Figure 4 This is a schematic diagram of the first embodiment of the present invention, wherein the sheath is in the retracted position, the balloon is in the inflated state, and the needle is in the extended position.

[0057] Figure 5 for Figure 2 Enlarged view of the far-end region of the device.

[0058] Figure 6 for Figure 3 Enlarged view of the far-end region of the device.

[0059] Figure 7 for Figure 3 The cross-sections of the three conduits in the device.

[0060] Figure 8 for Figure 4 Enlarged view of the far-end region of the device.

[0061] Figure 9 for Figure 4 The cross-section of the three conduits and three needles in the device.

[0062] Figure 10 This is a schematic diagram of an example handle.

[0063] Figure 11 This is a schematic diagram of an example of a possible support structure.

[0064] Figure 12 This is a schematic diagram of an example of another possible support structure.

[0065] Figure 13It is the cross-section of an inflatable balloon and a flexible tip.

[0066] Figure 14 This shows the distal region of the second embodiment of the present invention, wherein the balloon is in a deflated state and the two guide cannulas and needles are in a retracted position.

[0067] Figure 15 Another embodiment showing the distal region of the second embodiment of the present invention, wherein the balloon is inflated and the two guide cannulas and needles are in an extended position.

[0068] Figure 16 The cross-section of the guide sleeve is shown, with a bend at the distal end.

[0069] Figures 17 to 21 Here is a possible cross-section of the catheter body, where Figure 17 , 18 The embodiment shown in 20 does not use a guidewire, but Figure 19 , 21 The embodiment shown uses a guidewire. Detailed Implementation

[0070] This invention provides a drug delivery device, namely a catheter (such as a rapid-exchange catheter or a monolithic exchange catheter), which can be inserted into a blood vessel or lumen within the body to deliver drugs to the tissue surrounding the blood vessel or lumen. The drug delivery device includes:

[0071] An axially extending elongated member having a proximal portion, a distal portion, a first lumen, and a second lumen;

[0072] An inflatable balloon is connected to the distal portion of the axially extending elongated member, the inflatable balloon having a proximal end and a distal end connected by a working portion, the inflatable balloon also having an outer surface and an inner surface defining a balloon cavity, wherein a first lumen of the axially extending elongated member is in fluid communication with the balloon cavity.

[0073] Two or more guide sleeves, each guide sleeve having a proximal portion and a distal portion, wherein the proximal portion of each guide sleeve is connected to the axially extending elongated member; and

[0074] Two or more needles, each needle having a lumen and being housed in one of the guide sleeves, each needle being reversibly telescoping from the distal portion of the guide sleeve housing itself, wherein the second lumen of the axially extending elongated member is in fluid communication with the lumen of each needle.

[0075] Wherein, when the inflatable balloon is inflated, the distal portion of each of the guide sleeves does not exceed the outermost diameter of the outer surface of the inflatable balloon.

[0076] In some embodiments, the drug delivery device includes an inflatable balloon connected to the distal end of the axially extending elongated member. The drug delivery device also includes a balloon support element (such as a thread or other element to prevent axial compression of the balloon) located within the inflatable balloon, the balloon support element being connected to both the distal portion of the axially extending elongated member and the distal end of the inflatable balloon.

[0077] In some embodiments, an inflatable airbag is disposed at the distal portion of the axially extending elongated member. For example, the inflatable airbag is connected to and disposed on the distal portion of the axially extending elongated member.

[0078] In some embodiments, the axially extending elongated member includes a third lumen adapted to mount the drug delivery device onto a guidewire. This facilitates guiding the device to a target site within a vascular network.

[0079] The two or more guide sleeves are arranged at uniform intervals around the outer periphery of the axially extending elongated member.

[0080] In some embodiments, the distal portion of the guide cannula may not be fixed to the inflatable balloon and / or may be freely movable relative to the inflatable balloon. As explained herein, this allows the distal end of the guide cannula to be configured / positioned within the catheter in a way that allows the needle to be inserted into the catheter at a favorable angle (e.g., approximately perpendicular to the catheter wall).

[0081] In some embodiments, the distal portion of the guide cannula is configured to contact the outer surface of the inflatable balloon and move with the outer surface of the inflatable balloon as the balloon is inflated. This also helps to allow the distal end of the guide cannula to be positioned within the catheter in a configuration / posture that allows the needle to be inserted into the catheter at a favorable angle (e.g., approximately perpendicular to the catheter wall).

[0082] However, when the guiding cannula is configured to contact the outer surface of the inflatable balloon and move with the outer surface of the balloon during inflation, the guiding cannula can also be configured to at least partially return to its original shape or configuration after the balloon deflates. This ensures that the device can be easily withdrawn from the blood vessel after use without damaging the vessel wall, and similarly, the device can be reinserted into the blood vessel without damaging the vessel wall.

[0083] The inflatable balloon may include a proximal conical portion, a central cylindrical portion, and a distal conical portion. In this embodiment, the distal portion of the guide cannula is configured to contact the outer surface of the proximal conical portion of the inflatable balloon and move with the outer surface of the proximal conical portion. Therefore, the guide cannula can be moved by inflating the balloon, such that when the balloon is fully inflated, the guide cannula adopts a position that facilitates needle puncture of the blood vessel wall.

[0084] The device may further include a support element located at the proximal portion of each guide cannula to secure it in place while allowing the distal portion of the guide cannula to move and adopt the desired orientation during use. The distal tip of the guide cannula may bend outward and terminate at the proximal cone of the balloon. This means that the distal tip of the guide cannula will not extend (i.e., extend radially) beyond the outermost diameter of the balloon's outer surface, thus preventing contact between the distal tip of the guide cannula and the vessel wall as the guide device reaches the target site. Such contact between the guide cannula and the vessel wall during guidance could lead to damage to the vessel wall.

[0085] The guide cannula may have a slit formed by cutting one side of the guide cannula to control the direction of movement or deformation of the guide cannula during balloon inflation.

[0086] In some embodiments, the needle includes a curved end. The advantage of this is that as the needle extends from its housing cannula, the curved end bends radially outward from the axially extending elongated member. This configuration allows the needle to penetrate the catheter at an angle closer to perpendicular than a straight needle, resulting in a greater penetration depth to needle advance ratio.

[0087] In embodiments where the needle has a curved end, each needle may be configured such that the curved end bends radially outward from an axially extending elongated member as the needle extends from the sleeve containing itself.

[0088] In some embodiments, the guide sleeve may have a bend at its distal end, which helps to bend the originally straight needle when it extends from the guide sleeve, or helps to extend the bent needle when it extends from the guide sleeve.

[0089] In some embodiments, the distal end of each guide sleeve has an opening facing outward from the catheter, which also facilitates bending and / or orientation of the needle as it extends from the guide sleeve.

[0090] In some embodiments, the guide cannula is made of metal or alloy. This arrangement is particularly advantageous when the needle has a curved end, as the needle tip may come into contact with the edge of the guide cannula, and a plastic cannula may be punctured or damaged by the curved needle. Using a guide cannula made of metal or alloy is also advantageous when slight deformation of the needle is required during extension or retraction. For example, a straight needle can be used with a curved cannula to allow the needle to enter at an angle closer to vertical than when using a straight cannula.

[0091] Straight needles have an advantage because they are easier or cheaper to obtain.

[0092] Alternatively, if a smaller profile is desired when the needle is retracted (which can be achieved using a straight sleeve), a curved needle can be used in conjunction with a straight sleeve, achieving the same advantage in the curved needle's penetration angle.

[0093] In some embodiments, the device includes a sheath movably disposed on an axially extending elongated member. This sheath serves to accommodate the guide cannula and other components of the device as the guide device moves in and out of the target site, preventing damage to the device or the vessel wall during guidance.

[0094] In some embodiments, the sheath has an extended state and a retracted state. In the extended state, the sheath covers the entirety of the two or more guide cannulas and at least a portion of the inflatable balloon. In the retracted state, the sheath does not cover any part of the inflatable balloon. In some embodiments, in the retracted state, the sheath covers only a portion of the two or more guide cannulas, thereby providing greater flexibility in needle use while retaining the advantages discussed above.

[0095] The needle of the device of the present invention can reversibly extend and retract simultaneously, and / or reversibly extend and retract independently.

[0096] In some embodiments of the invention, the second lumen of the axially extending elongated member includes two or more sub-lumens, each of which is in fluid communication with the lumen of the needle. In some embodiments, the two or more sub-lumens are not in fluid communication with each other. This allows different fluids (such as different active agents) to be administered through different needles.

[0097] In some embodiments, the device further includes a support structure for positioning and securing the guide sleeve to the axially extending elongated member. This allows for control over the possible degree of movement of the distal end of the guide sleeve and more precise control over the location where the needle penetrates the blood vessel wall.

[0098] In some embodiments, the distal end (e.g., the distal tip) of the axially extending elongated member is connected to or has a flexible tip. This prevents damage to the blood vessel wall when the guiding device is directed to the treatment site.

[0099] In some embodiments, the device includes at least one radiopaque element to allow the operator to know the device's location within the patient's body. In some embodiments, the radiopaque element may be located within the balloon cavity, on an axially extending elongated member, on a guide cannula, and / or on the needle tip.

[0100] A handle may be disposed at the proximal end of the device, the handle comprising one or more of the following:

[0101] ● A structure for controlling the maximum extension depth of the needle;

[0102] ● A visual indicator that indicates the depth of needle extension (e.g., a visual indicator that indicates the current depth of needle extension so that the operator knows the current status of the needle);

[0103] ● A device for reversibly extending and retracting a needle from a cannula (e.g., a first device for coarsely reversibly extending and retracting a needle and a second device for finely reversibly extending and retracting a needle);

[0104] ● A device for extending and retracting the sheath;

[0105] ● The inflation port of the balloon (i.e., the inflation port that is fluidly connected to the first lumen of the axially extending elongated member); and

[0106] ● The inflation port of the needle (i.e., the inflation port that is fluidly connected to the second lumen of the axially extending elongated member).

[0107] As those skilled in the art will understand, these features help users operate the device of the present invention in a safe and efficient manner.

[0108] In some embodiments of the present invention, the device may be a rapid exchange catheter or a monolithic exchange catheter.

[0109] In a specific embodiment of the present invention:

[0110] Each of the needles includes a bent end;

[0111] The distal portion of the guide cannula can be configured to contact the outer surface of the inflatable balloon and move with the outer surface of the balloon as the balloon is inflated; and

[0112] After the balloon is deflated, the guide cannula returns to at least partially its original shape.

[0113] In another example of this embodiment, each needle may be configured such that when the needle extends from the guide sleeve containing itself, the bent end bends radially outward from the axially extending elongated member.

[0114] Further details of the device of the present invention and its use are described below.

[0115] In use, the device is first positioned with the balloon deflated and the sheath (if applicable) positioned over at least a portion of the balloon and the guide cannula, with the needle fully inside the guide cannula. Once in place, the sheath is retracted, the balloon is inflated, and the needle is advanced outward to the desired depth. The balloon's expansion pushes the distal end of the guide cannula outward. The inflatable balloon positions the device centrally within the vessel and anchors it in place. Furthermore, the guide cannula rests on the proximal cone of the balloon, thus the inflatable balloon acts as a stable platform for the guide cannula, providing optimal conditions for advancing the needle outward from the guide cannula into the vessel wall. Once the needle is in position, therapeutic agents are introduced through the needle for treatment. After treatment, the needle is retracted, the balloon is deflated, and the device is withdrawn.

[0116] The components of the device of the present invention will be described in detail below.

[0117] When the balloon is inflated so that its surface contacts the inner wall of the lumen, the device is secured within the lumen. Typically, the inflatable balloon is connected to and positioned on the distal portion of an axially extending elongated member. Normally, the balloon is a low-pressure balloon, meaning it is inflated to a relatively low pressure to avoid damage to the lumen / vessel. For example, the balloon can typically be inflated to 3 atmospheres or less, such as approximately 2 atmospheres. During use, the balloon can be inflated from a contracted (uninflated) state to a expanded (inflated) state. After inflation, the balloon can be deflated to return to a contracted / deflated state, allowing the catheter to be moved to another target site or withdrawn from the body. The inflatable balloon may have a proximal cone, a central cylindrical portion, and a distal cone.

[0118] In some embodiments of the invention, the axially extending elongated member may include a third lumen adapted to mount the device onto a guidewire. In catheter embodiments without a guidewire lumen, the balloon itself may be at risk of bending or contracting if it is unsupported as the catheter moves distally within the lumen. Therefore, when the device (catheter) does not include a guidewire lumen, a support element (such as a support wire) may be provided within the balloon. The support element (such as a support wire) may be connected to the catheter at two locations, distal and proximal to the balloon, respectively. For example, the support element may be connected to the distal portion of the axially extending elongated member and the distal end of the inflatable balloon, respectively.

[0119] The device comprises two or more guide cannulas, such as 2, 3, 4, 5, or 6 guide cannulas, each containing a retractable needle. Typically, the device includes 2 to 4 guide cannulas, such as 2 or 3. The guide cannulas are generally arranged at even intervals around the outer periphery of the axially extending elongated member to ensure uniform drug delivery to the tissue surrounding the lumen / vessel. The guide cannulas are typically made of a strong, rigid material, such as one or more metals or alloys, thereby giving the cannulas rigidity and allowing the needle placed within and / or extending from the cannulas to be bent or deformed. For example, the cannulas can be straight and allow for the deformation of a bent needle, thereby accommodating the needle within the cannulas.

[0120] Optionally, the cannula may include a bend that deforms a straight needle, which extends through the bend to allow the needle to bend. The proximal end of the guide cannula may be connected to the catheter body, and the distal end is a free end terminating at or adjacent to the proximal cone of the balloon. Typically, the guide catheter is arranged at even intervals around the catheter. The opening at the distal end of the guide cannula is usually configured such that the opening ends are perpendicular to the central axis of the catheter and outward. In some embodiments, the distal end of the guide cannula terminates with a bend that facilitates bending the needle tip as it extends from the guide cannula. In other embodiments, the guide cannula may be straight.

[0121] In some embodiments of the invention, the distal portion of each guide cannula is freely movable relative to the inflatable balloon and / or not fixed to the inflatable balloon. The distal portion of the guide cannula may be configured to contact the outer surface of the inflatable balloon and move with the outer surface of the inflatable balloon as the balloon is inflated. This means that the expansion of the balloon can position the cannula in the desired location so that the needle can extend. In this case, the guide cannula is typically configured to at least partially return to its original shape when the inflatable balloon deflates. In another configuration, the guide cannula may terminate at the proximal end of the inflatable balloon so that the position of the guide cannula is unaffected by the expansion and contraction of the balloon.

[0122] Typically, the distal end of the guide cannula can be positioned before or near the proximal end of the balloon. This means the guide cannula only moves near the proximal region of the balloon, which is usually tapered (i.e., the proximal cone). Therefore, when the balloon is fully inflated, the distal end of the guide cannula will not extend vertically beyond the outermost diameter of the balloon. This is crucial to avoid impacting the vessel / lumen wall during use, as such impact could damage the vessel or lumen.

[0123] The guide cannula can be supported by a support structure. The support structure positions and secures the guide cannula to an axially extending elongated member. Thus, the support structure can secure the proximal and middle portions of the cannula, but its distal portion can still bend outwards as the balloon expands. Optionally, the support structure can support and secure the entire guide cannula. In this case, the guide cannula can be mounted within the support structure. After balloon deflation, the guide cannula at least partially returns to its initial shape.

[0124] Each guide cannula houses a needle movably positioned within the lumen of the guide cannula so that each needle has both an extended and retracted state. The tip of each needle can bend laterally outward from the catheter (i.e., each needle may include a bent end). Therefore, a typical needle arrangement is as follows: when the needle extends from the cannula housing it, the bent end of each needle bends radially outward from an axially extending elongated portion. Generally, the radius of curvature of the needle is larger than that of the guide cannula in which it resides. In this case, when the needle transitions from the retracted to the extended state, the bend at the distal end of the guide cannula forces the needle tip to adopt a smaller radius of curvature. Because the needles are connected to the delivery cannula, the needles are in fluid communication with each other and with the proximal end of the catheter. These needles can reversibly extend and retract simultaneously and / or independently.

[0125] Each needle includes a lumen that is fluidly connected to a lumen (e.g., a second lumen) within an axially extending elongated member, allowing fluid to be delivered into the needle along the axial elongated member. The second lumen of the axially extending elongated member may include two or more sub-lumens, each fluidly connected to the lumen of the needle. Typically, the two or more sub-lumens are not fluidly connected to each other.

[0126] The distal end of the device may be provided with a flexible tip, which connects to the distal end of an axially extending elongated member. The proximal end of the device typically provides a handle by which the needle can be operated from an extended state to a retracted state and vice versa. The handle may include markers for determining needle displacement to aid in controlling the depth of penetration of the needle into the lumen wall and surrounding tissue. The handle may also include a structure for setting the maximum penetration depth of the needle during advancement. This structure is typically lockable and unlockable, allowing for easy and quick release when further needle advancement is required. The handle may include a device for converting rotational motion into lateral displacement, such as by using threads to reduce the force required for needle displacement.

[0127] The device may include at least one radiopaque element, i.e., an element visible under fluoroscopy or other imaging methods. At least one radiopaque element may be positioned in a location that facilitates catheter positioning, for example, within a balloon cavity, on an axially extending elongated member, on a guide cannula, and / or on the needle tip. A radiopaque element may also be positioned on a flexible tip (if present). Therefore, when the catheter is guided to a target site within the body, suitable imaging techniques can be used to provide accurate, real-time information about the catheter's position within the body.

[0128] The device may include a sheath movably disposed on an axially extending elongated member. The sheath is typically movably disposed on the portion of the axially extending elongated member having a guide cannula, i.e., the sheath is movably disposed on the guide cannula. The sheath typically has an extended state and a retracted state, and in some embodiments can be operated via a handle. In the extended state, the distal end of the sheath may be located distal to the distal end of the guide cannula, such that the sheath covers the entire guide cannula and at least a portion of the inflatable balloon. In the retracted state, the distal end of the sheath is typically close to the proximal cone of the balloon, and therefore does not cover a portion of the balloon. In the retracted state, the sheath typically covers only a portion of the cannula. Therefore, in the extended state, the sheath covers the cannula and protects the vessel / lumen wall from cannula damage as it moves along the vessel. In the retracted state, the cannula is exposed inside the vessel so that the needle can extend and penetrate the vessel wall. In a variable embodiment, the sheath may be a flexible sheath covering the proximal cone of the balloon, and when the balloon inflates, the sheath retracts naturally due to the force exerted by the balloon expansion. In another variant embodiment, the sheath may be rigid and cover the distal end of the guide cannula, with a weak point located above the guide cannula. During catheter tracking to the target site, the rigid sheath covers the distal end of the guide cannula, but when the balloon is inflated, the expansion of the balloon's diameter causes the rigid sheath to tear at the weak point, exposing the distal end of the guide cannula to allow for smooth needle extension.

[0129] The device may include a handle located at the proximal end of an axially extending elongated member, which serves several different purposes. The handle is provided with infusion and inflation Luer ports to allow for the injection of substances through the needle and balloon inflation. When a sheath is provided, the handle may also include a flushing Luer port to flush the interior of the sheath. The needle can be operated from a retracted state to an extended state and vice versa via the handle. Preferably, fine control of the needle operation to the desired depth helps to avoid tissue damage while ensuring that the drug is injected into the correct tissue. The handle may include structures for controlling the maximum extension depth of the needle. The handle may also include means for reversibly extending and retracting the needle from the guide cannula, such as a first means for coarsely reversibly extending and retracting the needle and a second means for finely reversibly extending and retracting the needle. For example, gears or screws may be provided on the handle to finely control the extension and retraction of the needle and the maximum extension depth. Furthermore, the means may reduce the force required to move the needle. The handle may include markings to help the user determine the displacement of the needle relative to the catheter as it extends from the guide cannula. The handle is also used to determine or set the fully extended and fully retracted states. The needle is fully retracted when it can no longer be retracted. In embodiments using a curved needle with a guide cannula having a free end and without a sheath, full retraction is crucial because the needle must retract sufficiently to prevent the guide cannula from bending outwards. To avoid damaging sensitive tissues due to excessive needle extension, a preset maximum extension is particularly important.

[0130] In an embodiment of the present invention:

[0131] Each needle includes a bent end;

[0132] The distal portion of the guide cannula is configured to contact the outer surface of the inflatable balloon and move with the outer surface of the inflatable balloon; and

[0133] After the balloon is deflated, the guide cannula can at least partially return to its original shape.

[0134] Optionally, each needle is configured such that when the needle extends from the sleeve containing itself, the bent end bends outward from the axially extending elongated member.

[0135] The present invention will now be described in detail with reference to the accompanying drawings.

[0136] Figures 1 to 4 The apparatus shown is a first embodiment of the present invention. Figures 1 to 4 Side views of device 100 at different stages of use. Figure 1In this configuration, the device 100 is covered by a sheath 101, which is fully extended. The sheath 101 protects the lumen wall when the device is tracked through it. A flexible tip 102 is located at the distal end of the device, thereby ensuring good trackability of the device 100 through the lumen. The handle 103 of the device includes a slider 111 for controlling the displacement of the sheath 101. The device also includes an inflation Luer port 112 (for inflating the inflatable balloon 121), a flushing Luer port 113 (for flushing the interior of the sheath 101), an injection Luer port 114 (allowing fluid to enter the needle 123), a nut 115 (controlling the displacement of the needle 123), and a bolt 116 (for moving the needle 123). Figure 1 The display device 100 shows its status when it is tracked to the treatment location. After the device 100 is tracked to the location, the sheath 101 will retract.

[0137] Figure 2 After the slider 111 is advanced proximally to the retracted position, the sheath 101 is in the retracted state. The retraction of the sheath 101 exposes the balloon 121 and the guide tube 122. When the sheath 101 is in the retracted position, the balloon can be deployed (inflated).

[0138] Figure 3 The device 100 is shown with the balloon 121 inflated. The inflatable balloon 121 secures the catheter to the vessel wall and centers the catheter in the lumen. The expansion of the balloon 121 also causes the distal end of the guide cannula 122 to shift outward. Once the device is in place and secured, the nut 115 can be rotated relative to the handle 103 to move the needle 123 forward. Figure 4 The display device shows the state of the device when the needle 123 is extended.

[0139] Figures 5 to 9 This is a view of the distal portion of the device according to the first embodiment of the present invention when it is not in use. Figure 5 Display as Figure 2 The distal portion of the device shown. When the balloon 121 deflates, the guide cannula 122 is mostly straight, and the distal end of the guide cannula 122 can be located within the folds of the balloon 121. Figure 6 Demonstrating the balloon 121 after inflation. Figure 3 The distal portion of the device shown. In the inflated state, the guide tube 122 contacts the balloon 121, and the balloon 121 pushes the distal end of the guide tube 122 outward. Figure 7 Showing as in Figure 3 A transverse view of the distal end of the device 100 when viewing the balloon 121 from the proximal end. It is particularly important that the guide cannula 122, when extended, does not exceed the outermost diameter of the balloon 121. This is because an excessively long guide cannula could contact the lumen wall, potentially causing damage during balloon inflation. Furthermore, the guide cannula prevents the balloon from directly contacting the lumen wall, which could lead to poor device anchoring.

[0140] Figure 8 As shown Figure 3 The distal portion of the device is shown when the balloon 121 is inflated and the needle 123 is extended. Preferably, the exposed portion of the needle bends outward in the same direction as the distal end of the guide cannula, thereby achieving a greater penetration depth and better control over the penetration depth. Figure 9 Showing as in Figure 4 A transverse view of the distal end of the device 100 when the balloon 121 is viewed from the proximal end.

[0141] Figure 10 This is a schematic diagram of an example of the handle 103. In this example, the proximal end of the handle is used to control the movement of the needle. When the nut 115 is rotated, the mating surface therein engages with the threads on the bolt 116, which is connected to the needle 123, thereby causing the needle 123 to move. The penetration depth of the needle 123 can be determined by the mark 131 on the handle.

[0142] Figure 11 and Figure 12 This demonstrates an example of a support structure. This support structure is used to ensure the guide cannula is in the correct position within the catheter. Figure 11 The support structure shown has four lumens, with the central lumen 201 located at the center of the device to accommodate any portion of the catheter, such as the inflation tube extending proximal to the balloon. Figure 11 In the support structure shown, three outer lumens 202 are equally spaced around the central lumen 201 used to accommodate the guide sleeve. Figure 11 The support structure shown is suitable for placement near the proximal end of the balloon. Figure 12 The support structure shown has evenly spaced grooves 203, in which guide sleeves can be placed. Figure 12 The support structures shown can be positioned on the proximal cone of the balloon to provide support at a more distal location. These support structures can be used independently, but when used together, they work synergistically to ensure the orientation of the guide cannula.

[0143] Figure 13 This is a cross-section of a possible structure of the balloon region. In some embodiments of this device, a guidewire is not used. Guidewires can be used to support a soft balloon in conventional balloon catheters. In embodiments of the invention where a guidewire is not required, a support wire 206 can be used to support the balloon 205. The support wire 206 is connected to the distal balloon strut 207 and the proximal balloon strut 208. A flexible tip 204 can be attached to the distal end of the balloon to improve the device's trackability.

[0144] Figure 14 and Figure 15An apparatus according to a second embodiment of the invention is shown, with distal regions of the apparatus 300 displayed at different stages of use. In the apparatus 300 according to the second embodiment, a plurality of guide tubes (not shown) are housed in a support structure 302 fixed to an elongated member. The guide tubes do not include any “free” portions that move with the balloon. Instead, each guide tube terminates before the balloon 301 and therefore does not contact the balloon 301.

[0145] Figure 14 The device 300 is shown with the balloon 301 in the deflated state and the needle 303 in the retracted position, indicating that the device 300 is in the tracked position. Figure 15 Device 300 showing the balloon 301 inflated and the needle 303 extended.

[0146] Since the guide cannula terminates before the balloon 301, it is crucial that the needle 303 extending from the guide cannula has a sufficiently small radius of curvature to ensure that the inflatable balloon 301 is not punctured.

[0147] Figure 16 The distal end of the guide sleeve 209 is shown, terminating at a bend 210. To maintain a small device profile, the bend 210 is designed to be short, thus preventing a significant increase in the profile of the guide sleeve 209. This distal bend 210 allows the needle to extend from the guide sleeve at an angle. Furthermore, the bend 210 causes the needle extending from the guide sleeve 209 to deform into a curved shape. Both of these advantages are beneficial in various embodiments of the device.

[0148] Figure 17 and Figure 18 The figures show cross-sections of two possible catheter body structures in a device embodiment that does not require a guidewire. Although the sheath is not shown in either figure, it may be present. Figure 17 The main structure is shown, consisting of two components: a dual-lumen tube 401 and an injection tube 403. The dual-lumen tube 401 contains an inflation lumen 402 (i.e., the first lumen) and an injection tube 403 including a second lumen. The injection tube 403 is movable relative to the dual-lumen tube 401, allowing for needle advance and retraction. The dual-lumen tube 401 is also directly connected to a balloon, allowing the balloon to be inflated and deflated through the inflation lumen 402. Figure 18 The main structure is shown with three components: a double-lumen tube 404, an injection tube 406, and an inflation tube 405. Figure 18 The structure shown is similar to Figure 17 Similar to the one shown, but the dual-lumen tube 404 is not directly connected to the balloon. Figure 18 In this configuration, the inflation tube 405 is directly connected to the balloon for inflation and deflation. The inflation tube 405 is also not movable relative to the double-lumen tube 404.

[0149] Figure 19This diagram shows a cross-section of a possible catheter body structure in an embodiment of a device requiring a guidewire. The three-lumen tube 411 includes an inflatable lumen 412 (i.e., a first lumen), an injection tube 414 including a second lumen, and a guidewire tube 413. Figure 17 and Figure 18 Similarly, a sheath can be provided, and the injection tube 414 is movable relative to the three-lumen tube 411 to control the needle. The balloon can also be directly connected to the three-lumen tube 411 for inflation and deflation via the inflation lumen 412, or connected to a separate inflation tube located within the inflation lumen 412, similar to... Figure 18 As shown.

[0150] Figure 20 and Figure 21 Cross-sections of two possible structures of the catheter body are shown in an embodiment of a device with a sheath. Figure 20 The diagram illustrates a possible structure of the catheter body in this embodiment of the device, which does not require a guidewire and comprises a sheath 501, an inflation tube 502 containing a first lumen, an injection tube 503 containing a second lumen, and a body tube 504. The injection tube 503 is housed internally and movable relative to the body tube 504. The sheath 501 houses and is movable relative to the inflation tube 502 and the body tube 504. The inflation tube 502 and the body tube 504 can be joined together by adhesive or by using heat shrink tubing around them.

[0151] Figure 21 A cross-section of a possible structure of the catheter body in this embodiment of the device is shown. The device requires a guidewire, which consists of a sheath 511, a guidewire tube 512, an inflation tube 513 including a first lumen, two body tubes 514 and 516, and two needles 515 and 517. Figure 21 In the illustrated embodiment, the needles are independent of each other, and the second lumen includes two sub-lumens formed within the body tubes 514 and 516. Needles 515 and 517 are located within and movable relative to the body tubes 514 and 516, respectively, each body tube 514 or 516 constituting a sub-lumen of the second lumen. The sheath 511 houses and is movable relative to the guidewire tube 512, the inflation tube 513, and the two body tubes 514 and 516. The guidewire tube 512, the inflation tube 513, and the body tubes 514 and 516 can be joined together by adhesive or by using heat-shrink tubing around them.

[0152] refer to Figures 1 to 9This describes a first embodiment of the invention. The device according to the first embodiment includes three guide cannulas, the distal ends of which terminate at the proximal cone of a balloon, adjacent to the proximal end of the balloon's working length, such that the guide cannulas can bend outwards as the balloon inflates. Each guide cannula contains a retractable needle that bends laterally outwards from the catheter at its distal end. The guide cannulas are evenly distributed around the catheter and supported by a support structure. The support structure supports the cannulas in the proximal and middle regions to prevent unwanted movement, but the distal ends of the cannulas can move as the balloon expands. The device includes a support wire supporting the balloon to prevent folding or retraction, and also includes a flexible tip to improve the device's trackability. Although not shown in the figures, it will be understood by those skilled in the art that the device of the first embodiment may include a retractable sheath as described in detail herein to cover the cannulas as the catheter is guided along the blood vessel to the target site. In some cases, the first embodiment may include a sheath covering both the balloon and the guide cannulas.

[0153] Reference Figure 14 and Figure 15 The following describes a second embodiment of the invention. In this embodiment, the device includes two guide cannulas terminating before the balloon (i.e., terminating proximally to the balloon), such that the guide cannulas are unaffected by the balloon during inflation. This means that the distal end of the guide cannulas will not shift with balloon expansion, therefore the needle must have a certain curvature to ensure that it does not puncture the balloon when extending from the guide cannulas. This can be achieved by using a needle with a natural curvature, meaning a needle that bends once no longer constrained by the cannulas. Optionally, the cannulas may include a curved distal portion, thereby bending the needle as it extends from the cannulas. The cannulas are supported by a support structure, but in this embodiment, the distal end of the cannulas does not need to move with balloon expansion, so the support structure can hold the entire cannulas in place. In the illustrated embodiment, the device does not include a flexible tip, although this can be easily incorporated into the embodiment by those skilled in the art. The device includes a cannula / lumen through which a guidewire passes. In some cases, this second embodiment may include a sheath covering the balloon and the guide cannulas.

[0154] The third embodiment of the present invention corresponds to the first embodiment, except that this embodiment does not include a supporting guidewire or flexible tip, but includes a lumen or cannula for guiding the guidewire through. This third embodiment also includes two or more guiding cannulas.

[0155] The fourth embodiment of the invention corresponds to the first embodiment, except that this embodiment includes two guide cannulas, each containing a needle, instead of three cannulas / three needles. Modifications can be made to the specific embodiments described above (such as the first, second, third, and fourth embodiments) to include any other functionality disclosed herein. For example, each specific embodiment can be modified to include a sheath covering the balloon and the guide cannulas. All embodiments disclosed herein can be modified to include a catheter / lumen providing passage for a guidewire; or to include a support wire, preferably combined with a flexible tip. Typically, the device does not simultaneously include a support wire and a lumen for the guidewire, as using a guidewire would make the support wire redundant. Generally, when using a support wire, it is preferable to combine it with a flexible tip (because the support wire does not guide the passage of the device but only supports the balloon structure), but when using a guidewire, the guidewire guides the device through the blood vessel, in which case the flexible tip is unnecessary. Finally, any embodiment of the first to fourth embodiments can include radiopaque elements.

[0156] Generally, devices for larger vessels may include a support wire and a flexible tip, while devices for smaller, more peripheral vessels may be used in conjunction with a guidewire to facilitate guidance within narrower vessels. Furthermore, devices for smaller vessels can use fewer needles, such as two needles, and the profile of the guide cannula adapted to the needles is smaller than that for devices used in larger vessels. For example, for devices for smaller vessels, the guide cannula is not placed on the balloon but rather positioned anterior to the balloon to achieve a smaller profile.

[0157] As will be understood by those skilled in the art, although the embodiments described herein have specific features, the apparatus provided by the present invention may have any technically reasonable combination of the features described herein, such as any technically reasonable combination of the features of the first to fourth embodiments described herein.

[0158] The following is a brief description of how to use the catheter of the present invention. This method can be used in all embodiments of the device. The method may include the following steps.

[0159] 1. Track the catheter to the desired position while it is deflating and the needle is retracted.

[0160] 2. Optionally, X-ray fluoroscopy or other imaging techniques may be used to confirm that the catheter is in place.

[0161] 3. Optionally, the balloon can be inflated to a suitable pressure, such as 2 atmospheres, via the handle.

[0162] 4. Optionally, X-ray fluoroscopy or other imaging techniques may be used to confirm that the balloon is inflated and the guide cannula is in place.

[0163] 5. Optionally, the needle can be operated from the retracted position to the extended position via the handle.

[0164] 6. Optionally, the substance for treatment can be injected into the target through a needle via a handle.

[0165] 7. Optionally, the needle can be operated from the extended position to the retracted position via the handle.

[0166] 8. Optionally, deflate the balloon via the handle.

[0167] 9. Optionally, X-ray fluoroscopy or other imaging techniques may be used to confirm that the balloon has been deflated and the guide cannula is in the deflated position.

[0168] 10. If multiple injections are required, repeat steps 1-9.

[0169] 11. After all injections are completed, remove the catheter from the body.

[0170] As described herein, the catheter may include a sheath that covers the guide cannula to prevent damage to the vessel wall from the guide cannula. Examples of methods of use when the catheter includes a sheath are as follows.

[0171] 1. Track the catheter to the desired position while it is deflating and the needle is retracted.

[0172] 2. Optionally, X-ray fluoroscopy or other imaging techniques may be used to confirm that the catheter is in place.

[0173] 3. Retract the sheath to the retracted position.

[0174] 4. Optionally, the balloon can be inflated to a suitable pressure, such as 2 atmospheres, via the handle.

[0175] 5. Optionally, X-ray fluoroscopy or other imaging techniques may be used to confirm that the balloon is inflated and the guide cannula is in place.

[0176] 6. Optionally, the needle can be operated from the retracted position to the extended position via the handle.

[0177] 7. Optionally, the substance for treatment can be injected into the target through a needle via a handle.

[0178] 8. Optionally, the needle can be operated from the extended position to the retracted position via the handle.

[0179] 9. Optionally, the balloon can be deflated via the handle.

[0180] 10. Optionally, X-ray fluoroscopy or other imaging techniques may be used to confirm that the balloon has been deflated and the guide cannula is in the deflated position.

[0181] 11. Stretch the sheath to the extended position.

[0182] 12. If multiple injections are required, repeat steps 1-11.

[0183] 13. After all injections are completed, remove the catheter from the body.

[0184] In embodiments without a sheath, there is a risk of damage to the vessel wall due to the guiding cannula. To prevent this, a guiding catheter can be used. An example method of using a catheter in conjunction with a guiding catheter is provided below. This method can be used in all embodiments of the device, although it is generally used for embodiments without a sheath.

[0185] 1. Follow the guiding catheter until it passes the treatment point distally.

[0186] 2. Track the catheter to the desired position while it is deflating and the needle is retracted.

[0187] 3. Optionally, X-ray fluoroscopy or other imaging techniques can be used to confirm that the catheter is in place.

[0188] 4. Pull the guide catheter back until the distal end of the guide catheter is close to the distal end of the support structure (if any).

[0189] 5. Optionally, the balloon can be inflated to a suitable pressure, such as 2 atmospheres, via the handle.

[0190] 6. Optionally, X-ray fluoroscopy or other imaging techniques may be used to confirm that the balloon is inflated and the guide cannula is in place.

[0191] 7. Optionally, the needle can be operated from the retracted position to the extended position via the handle.

[0192] 8. Optionally, the substance for treatment can be injected into the target through a needle via a handle.

[0193] 9. Optionally, the needle can be operated from the extended position to the retracted position via the handle.

[0194] 10. Optionally, deflate the balloon via the handle.

[0195] 11. Optionally, X-ray fluoroscopy or other imaging techniques may be used to confirm that the balloon has been deflated and the guide cannula is in the deflated position.

[0196] 12. If multiple injections are required, repeat steps 1-11.

[0197] 13. After all injections are completed, remove the catheter from the body.

[0198] In all embodiments of the catheter, the positions of the distal ends of the guiding catheter and the support structure are crucial for catheter positioning during use. The distal position of the guiding cannula determines where the needle penetrates the vessel / lumen wall, and is therefore critical; thus, the distal end of the guiding cannula can be used for catheter positioning at the target site. The distal position of the support structure supports the catheter components in place, and is also critical. Consequently, the proximal portion of the support structure generally does not change size when the balloon is inflated. Therefore, when using a sheath or guiding catheter, it is particularly important to ensure that the distal end of the sheath or guiding catheter is close to the distal end of the support structure before balloon inflation. To facilitate visibility of the distal end of the guiding cannula during use, the entire guiding cannula can be made of a radiopaque material, or a radiopaque material can be placed at the distal end of the guiding cannula. Another method to make the distal end of the guiding cannula visible is to place a radiopaque material within the balloon, such as on the guidewire lumen or support wire, or on any similar structure at the distal end of the guiding cannula. To facilitate visibility of the distal end of the support structure during use, the entire support structure can be made of a radiopaque material, or a radiopaque material can be disposed at the distal end of the support structure. To facilitate visibility of the distal end of the sheath during use, a radiopaque material can be disposed at the distal end of the sheath. The methods for making the distal ends of the guide sleeve, support structure, and sheath visible are not limited to the methods described above. The radiopaque materials described herein can be used alone or in combination.

[0199] In embodiments of the invention, the distal end of the guide sleeve terminates with a bend, the curvature of which is used to determine the curvature and direction of the extended needle. In these embodiments, since the radius of curvature at the end of the guide sleeve is always smaller than the radius of curvature of the contained needle (i.e., a tighter bend), as the needle moves from the retracted position to the extended position, its radius of curvature decreases because it is forced through the guide sleeve with the tighter curvature. During this process, the direction of the needle's curvature also follows the direction of curvature of the guide sleeve. By setting the radius and direction of curvature of the needle through the guide sleeve, the penetration depth of the needle can be controlled more precisely. Another advantage of the bend at the distal end of the guide sleeve is that a straight needle can be used; the bend in the guide sleeve forces the straight needle to bend as it extends from the sleeve. The radius of curvature used by the needle depends on the curvature present at the distal end of the guide sleeve. Using a straight needle is advantageous because it avoids deformation of the needle during storage in a straight sleeve (a bent needle can cause deformation and damage in a straight sleeve).

[0200] When the needle bends outward in the extended position, the force required to move it from the retracted position to the extended position is greater, and vice versa. There are several reasons for this greater force requirement. If a curved needle is used, it will constantly press against the inner wall of the guide sleeve, and the resulting friction may require a significant force to overcome. Furthermore, when the curved needle retracts from the extended position to the retracted position, force is needed to bend the needle from a curved structure to a straight structure. If the end of the guide sleeve is curved, the bending radius of the needle decreases when moving it from the retracted position to the extended position, thus requiring a large force. Because a large force is required to move the needle in either direction, it is particularly important that the distal end of the device, connecting to the handle, is made of a material that will not stretch or deform, as this will affect the safety and performance of the device. Metals or alloys can provide the required properties but are too rigid. One way to overcome the rigidity of metal or alloy tubing is to pattern the tubing using laser cutting to increase its flexibility. Due to the large force required, components such as gears or threads can be incorporated into the handle to amplify the force applied to the needle.

[0201] In catheter embodiments where the distal end of the guide cannula is free, there is a risk of damage to the lumen wall from the distal end of the guide cannula during the initial tracking of the catheter to the target site. One possible solution is to place the distal end of the guide cannula within a fold of the folded balloon when the catheter is first inserted into the lumen and tracked to the target site. This prevents the distal end of the guide cannula from directly interacting with the lumen wall, thus protecting the lumen wall. Placing the distal end of the guide cannula within the balloon fold can be done during or after folding. For optimal results, the number of folds should be equal to the number of guide cannulas, providing the longest possible balloon fold for that number of guide cannulas. Another possible solution is to attach a soft material to the distal end of the guide cannula, which can cover the entire periphery or part of the distal end. This soft material can be a low-hardness polymer that will not impede needle movement. Yet another possible solution is to use a sheath that is removably mounted on the guide cannula as described above. During catheter tracking to the target site, the sheath will cover the distal end of the guide cannula. Once the catheter is in place, the sheath is retracted, exposing the distal end of the guide cannula to allow for smooth needle extension. Another possible solution is to place a flexible sheath at the distal end of the guide cannula. During catheter tracking to the target site, the flexible sheath covers the distal end of the guide cannula, but when the balloon is inflated, the balloon diameter expands, and the increased angle between the guide cannulas causes the flexible sheath to peel off, exposing the distal end of the guide cannula to allow for smooth needle extension. Yet another possible solution is to place a rigid sheath at the distal end of the guide cannula, with a weak point formed within the rigid sheath, located above the guide cannula. During catheter tracking to the target site, the rigid sheath covers the distal end of the guide cannula, but when the balloon is inflated, the balloon diameter expands, causing the rigid sheath to tear at the weak point, exposing the distal end of the guide cannula to allow for smooth needle extension. As those skilled in the art will understand, the device may include a combination of various features designed to prevent damage to the vessel / luminal wall, and is not limited to the above possible solutions. These suitable features may be used independently or in combination.

[0202] In catheter embodiments where the distal end of the guiding catheter is free, there is a possibility that the guiding cannula may bend not only outwards but also laterally, due to the lack of preferential axial bending. One possible solution is to modify the guiding cannula to preferentially bend in only one direction. This can be achieved through various methods, such as using a laser to cut one or more slits in the guiding cannula to make it easier to bend, or using a guiding cannula of a certain shape. Another method is to make the guiding cannula from materials of different stiffness, allowing it to bend in a specific direction. As will be understood by those skilled in the art, any method can be used to minimize the possibility of lateral bending of the guiding cannula.

[0203] In catheter embodiments using needles with curved ends, prolonged storage of the curved needle body in a straight structure may risk increasing the needle's radius of curvature. Fischell et al. investigated this problem in U.S. Patent No. 8,740,849, proposing a solution of keeping the needle extended during storage. The needle is stored extended when there are no obstructions at the distal opening of the guide cannula. However, when using a sheath or when the guide cannula is placed within a fold of a retractable balloon, both the sheath and the fold will obstruct the needle. For the sheath, one possible solution is to keep it retracted during storage, thus not obstructing the needle. For the fold, one possible solution is to position the needle tip at an angle during storage so that the needle avoids the fold when extended outward during use. This can be achieved by rotating the infusion cannula connected to the needle. Rotation can be performed via a handle, and the angle of rotation and the outward position can be marked on the handle to ensure correct positioning. An example of how such a catheter can be prepared is described below.

[0204] 1. Place the distal end of the guide cannula within the folded balloon fold.

[0205] 2. Set the needle's orientation to an angled position.

[0206] 3. Slowly and carefully extend the needle to ensure that it does not damage the balloon.

[0207] 4. Pack and store the catheter until use.

[0208] 5. Before use, retract the needle to its fully retracted state.

[0209] 6. Set the needle orientation to outward.

[0210] 7. Use the catheter as described above.

[0211] In catheter embodiments with a sheath, there is a possibility of air being released from the sheath when it moves from an extended to a retracted position within the lumen. If the lumen is a vessel flowing into a small blood vessel, the released air can form bubbles and cause air embolism, posing a danger to the patient. One method to significantly reduce the risk of air embolism is to flush the inside of the sheath with water, preferably before the catheter is inserted into the patient.

[0212] In some embodiments, the distal end of the guide cannula is a free end and terminates at the proximal cone of the balloon. A free distal end means that when the balloon is inflated, the inflated balloon exerts an outward force on the guide cannula, causing the free distal end to bend outward. Because the distal end of the guide cannula is free, the bending of the guide cannula is more gradual. Compared to the devices described in U.S. Patent No. 6,692,469 to Chow et al. and U.S. Patent No. 7,273,469 to Chan et al., this arrangement allows for a smaller force to move the needle from the retracted position to the extended position and vice versa. Based on the arrangement where the distal end of the guide cannula terminates at the proximal cone of the balloon, when the balloon is fully inflated, the distal end of the guide cannula will not extend beyond the outermost diameter of the balloon in the vertical direction, thereby reducing the possibility of vascular injury due to contact between the hollow distal end of the guide cannula and the vessel wall. Using a low-pressure balloon also reduces the possibility of vascular injury. Simultaneously, the expansion of the balloon also positions the distal tip of the guide cannula close to the inner wall of the vessel. The guiding cannula is supported by a balloon, with its distal tip close to the inner wall of the blood vessel. Based on this setup, the guiding cannula provides radial and lateral stability to the needle as it passes through the target vessel wall, allowing the use of finer needles.

[0213] Before needle extension, a balloon can be used to support and position the guide cannula. While such balloon use is described in Mirzaee's U.S. Patent No. 6,283,947, the rationale for its use differs. In the prior art described by Mirzaee, the balloon's primary purpose is to guide the injection port at an angle away from the catheter's central axis and into the arterial wall. In this invention, the balloon serves several purposes. As previously described, the balloon's expansion is used to position and support the guide cannula. Upon expansion, the balloon fills the lumen, and the balloon wall contacts the lumen wall. Thus, 1) the catheter is centered relative to the lumen, ensuring each needle has the same penetration depth as it extends outward; 2) the distal end of the catheter is secured within the lumen, preventing accidental displacement; and 3) the lumen can have an irregular or flattened cross-sectional shape to allow for circumferential drug deposition. Therefore, this invention is applicable to a variety of different physiological cavities, not limited to those with a circular cross-section.

[0214] Greater penetration depth can be achieved using needles with pre-bent ends. The use of needles with pre-bent ends has been described in the prior art. However, existing infusion catheters do not provide sufficient support for the needle, thus hindering the use of finer needles. The Peregrine system described in U.S. Patent No. 8,740,849 to Fischell et al. TM (PeregrineSystem TM The invention utilizes a needle with a pre-bent end supported by another structure, thus allowing the use of finer needles. This invention is related to the Peregrine system. TM(Peregrine System TM The two main differences between this invention and the previous one are that, in this invention, the guide cannula is positioned before the needle is extended, and this invention uses a balloon during catheter positioning and needle extension. These features of the invention overcome the limitations of the Peregrine system discussed above. TM (Peregrine System TM The disadvantages of ).

[0215] In the embodiments and aspects of the invention described above, certain features are described in singular or plural form. Where it is used herein, references to the singular shall be construed as including the plural, and vice versa, where technically reasonable. For example, where technically reasonable, if the device includes multiple guide sleeves, one guide sleeve may include multiple guide sleeves.

Claims

1. A drug delivery device, comprising: An axially extending elongated member having a proximal portion, a distal portion, a first lumen, and a second lumen; An inflatable balloon is connected to the distal portion of the axially extending elongated member, the inflatable balloon having a proximal end and a distal end connected by a working portion, the inflatable balloon also having an outer surface and an inner surface defining a balloon cavity, wherein a first lumen of the axially extending elongated member is in fluid communication with the balloon cavity. Two or more guide sleeves, each guide sleeve having a proximal portion and a distal portion, wherein the proximal portion of each guide sleeve is connected to the axially extending elongated member; and Two or more needles, each needle having a lumen and housed in one of the guide sleeves, each needle being reversibly telescoping from the distal portion of the guide sleeve housing itself, wherein the second lumen of the axially extending elongated member is in fluid communication with the lumen of each needle; wherein, When the inflatable balloon is inflated, the distal portion of each of the guide sleeves does not exceed the outermost diameter of the outer surface of the inflatable balloon. The feature is that the distal portion of each of the guide sleeves is freely movable relative to the inflatable balloon, and / or the distal portion of each of the guide sleeves is not fixed to the inflatable balloon.

2. The drug delivery device of claim 1, wherein: The inflatable balloon is connected to the distal end of the axially extending elongated member.

3. The drug delivery device as described in claim 2, characterized in that: It also includes a balloon support element located within the inflatable balloon, the balloon support element being connected to the distal portion of the axially extending elongated member and the distal end of the inflatable balloon, respectively.

4. The drug delivery device as described in claim 1 or 2, characterized in that: The axially extending elongated member includes a third lumen adapted to mount the drug delivery device on a guidewire.

5. The drug delivery device as claimed in claim 1, characterized in that: The inflatable balloon is disposed on the distal portion of the axially extending elongated member.

6. The drug delivery device according to any one of claims 1-3 and 5, characterized in that: The guide sleeves are arranged at uniform intervals around the outer periphery of the axially extending elongated member.

7. The drug delivery device according to any one of claims 1-3 and 5, characterized in that: The distal portion of the guide sleeve is configured to contact the outer surface of the inflatable balloon and move with the outer surface of the inflatable balloon as the balloon is inflated.

8. The drug delivery device as claimed in claim 7, characterized in that: The guide sleeve is configured to at least partially return to its original shape when the inflatable balloon is deflated.

9. The drug delivery device according to any one of claims 1-3 and 5, characterized in that: The inflatable balloon has a proximal cone, a middle cylindrical portion, and a distal cone.

10. The drug delivery device as claimed in claim 9, characterized in that: The distal portion of the guide cannula is configured to contact the outer surface of the proximal cone of the inflatable balloon.

11. The drug delivery device according to any one of claims 1-3 and 5, characterized in that: Each of the guide sleeves includes a slit formed by cutting one side of the guide sleeve.

12. The drug delivery device according to any one of claims 1-3 and 5, characterized in that: The guide sleeve is made of metal.

13. The drug delivery device according to any one of claims 1-3 and 5, characterized in that: It also includes a sheath that is movably disposed on the axially extending elongated member.

14. The drug delivery device as claimed in claim 13, characterized in that: The sheath has an extended state and a retracted state. In the extended state, the sheath covers the entirety of the two or more guide sleeves and at least a portion of the inflatable balloon. In the retracted state, the sheath does not cover a portion of the inflatable balloon.

15. The drug delivery device according to any one of claims 1-3 and 5, characterized in that: The needle can extend and retract simultaneously and reversibly.

16. The drug delivery device according to any one of claims 1-3 and 5, characterized in that: The needle can extend and retract independently and reversibly.

17. The drug delivery device as claimed in claim 1, characterized in that: Each of the needles includes a bent end, and each of the needles is configured such that when the needle extends from the guide sleeve containing itself, the bent end bends radially outward from the axially extending elongated member.

18. The drug delivery device according to any one of claims 1-3 and 5, characterized in that: The second lumen of the axially extending elongated member includes two or more sub-lumens, each of which is fluidly connected to the lumen of the needle.

19. The drug delivery device according to any one of claims 1-3 and 5, characterized in that: It also includes a support structure for positioning the guide sleeve and securing the guide sleeve to the axially extending elongated member.

20. The drug delivery device according to any one of claims 1-3 and 5, characterized in that: The distal end of the axially extending elongated member is connected to a flexible tip.

21. The drug delivery device according to any one of claims 1-3 and 5, characterized in that: The drug delivery device is a rapid-exchange catheter or a monolithic exchange catheter.

22. The drug delivery device according to any one of claims 1-3 and 5, characterized in that: It includes at least one radiopaque element located within the balloon cavity, or on the axially extending elongated member, or on the guide sleeve, and / or on the needle.

23. The drug delivery device according to any one of claims 1-3 and 5, characterized in that: It also includes a handle disposed at the proximal end of the axially extending elongated member.

24. The drug delivery device as claimed in claim 23, characterized in that: The handle includes a structure for controlling the maximum extension depth of the needle.

25. The drug delivery device as claimed in claim 23, characterized in that: The handle includes a means for reversibly extending and retracting the needle from the guide sleeve.

26. The drug delivery device as claimed in claim 25, characterized in that: The device includes a first means for reversibly extending and retracting the needle and a second means for reversibly extending and retracting the needle.

27. The drug delivery device as claimed in claim 23, characterized in that: The handle includes a visual indicator that indicates the depth of needle extension.

28. The drug delivery device according to any one of claims 1-3 and 5, characterized in that: The guide sleeve includes a curved portion at the distal end, and each guide sleeve has an opening at the distal end that faces outward from the conduit.

29. The drug delivery device according to any one of claims 1-3 and 5, characterized in that: Each of the needles includes a bent end; The distal portion of the guide sleeve is configured to contact the outer surface of the inflatable balloon and move with the outer surface of the inflatable balloon; and After the inflatable balloon is deflated, the guide sleeve at least partially returns to its original shape. Each of the needles is configured such that when the needle extends from the guide sleeve containing itself, the bent end bends radially outward from the axially extending elongated member.

30. The drug delivery device as claimed in claim 13, characterized in that: The sheath has an extended state and a retracted state. In the extended state, the sheath covers the entirety of the two or more guide sleeves and at least a portion of the inflatable balloon. In the retracted state, the sheath covers only a portion of the two or more guide sleeves.

31. The drug delivery device according to any one of claims 1-3 and 5, characterized in that: The second cavity of the axially extending elongated member includes two or more sub-cavities, which are not in fluid communication with each other.

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