A non-penetrating microcatheter for local administration and a medical device comprising the same

Abstract

The application provides a microcatheter for local administration, which comprises a delivery section, a fixing section, a perforating section and a terminal section from proximal end to distal end, the delivery section, the fixing section and the perforating section have communicated inner cavities, the outer diameter is 1.5F-5F, and the inner diameter is 0.40mm-1.5mm; the length of the terminal section is 1-40mm, and a guide wire through hole is arranged; the fixing section has a preformed arc-shaped outer shape; the end of the perforating section is blocked, side perforating holes are arranged on the perforating section, and a marker is arranged at the joint of the perforating section and the fixing section; and an anticoagulant coating is arranged on the outer surface of the microcatheter. The microcatheter is not prone to thrombosis for long-term placement in an artery, is suitable for local administration of patients with head, liver and coronary artery diseases in the body, is suitable for local administration of chemotherapy for cancer patients, and can reduce the administration amount to less than one tenth of the conventional administration amount.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical treatment, in particular to a non-through microcatheter for local administration and a medical device comprising the same. BACKGROUND

[0002] It is difficult to treat the head, liver, coronary artery and other regions of the human body and cancer patients through local administration. In order to make the drug reach the required concentration in the treatment area, it is usually necessary to increase the dose of administration, which will cause drug side effects and organ damage. Local administration can effectively deal with the problem of drug damage caused by conventional administration, especially for local administration of specific parts of cancer patients, which can significantly reduce the adverse effects of overuse of drugs. In addition, cardiovascular disease patients usually need to take anticoagulant drugs for treatment. Patients taking anticoagulant drugs will face great risks when they need surgery for other diseases. For example, anticoagulant drugs must be stopped during surgical treatment of gastrointestinal bleeding, which can easily cause myocardial infarction. For example, for lung cancer patients with heart disease, a stent implantation surgery is usually required before surgery, otherwise the patient cannot tolerate surgical anesthesia or surgery. Once the stent is implanted, it is usually necessary to take anticoagulant drugs continuously for 1 year, which leads to massive bleeding after surgery and becomes a difficult problem. Local anticoagulant administration can effectively deal with these risks, so a simple and effective means is needed to achieve local administration. SUMMARY

[0003] The present application provides a microcatheter for local administration, which comprises the following embodiments:

[0004] Embodiment 1, a microcatheter for local administration, comprising in order from proximal end to distal end: a delivery segment, a fixed segment, a perforated segment and a terminal segment, the delivery segment, the fixed segment and the perforated segment have a continuous inner cavity, the outer diameter is 1.5F to 5F, and the inner diameter is 0.40mm to 1.5mm; the length of the terminal segment is 1 to 40mm, and a guide wire through hole is arranged; the fixed segment has a preformed arc-shaped outer shape for relatively fixing the position between the microcatheter and the blood vessel by shape after the microcatheter is arranged; the end of the perforated segment is blocked, so that the perforated segment is not connected with the terminal segment, a side perforation is arranged on the perforated segment, and a marker is arranged near the perforated segment, for example, a marker is arranged at the connection between the perforated segment and the fixed segment, to help external equipment detect its position in the patient's body; an anticoagulant coating is arranged on the outer surface of the microcatheter.

[0005] Embodiment 2, the microcatheter for local administration according to Embodiment 1, wherein the length of the terminal segment is 6mm to 20mm.

[0006] Embodiment 3. The microcatheter for local drug delivery according to Embodiment 1, wherein the outer diameter of the delivery segment, the fixation segment and the fenestration segment is 1.7F to 4F, preferably 1.7 to 2.6F, and the inner diameter is 0.45mm to 1.2mm.

[0007] Embodiment 4. The microcatheter for local drug delivery according to Embodiment 1, wherein the anti-thrombogenic coating is a heparin coating or a heparinoid coating, and optionally the anti-thrombogenic coating is hydrophilic.

[0008] Embodiment 5. The microcatheter for local drug delivery according to Embodiment 1, wherein the inner and outer surfaces of the microcatheter are provided with an anti-thrombogenic coating.

[0009] Embodiment 6. The microcatheter for local drug delivery according to Embodiment 1, wherein the length of the delivery segment is 0.4 to 1.5m, 0.7 to 1.3m, 0.8 to 1.3m or 1.1 to 1.3m.

[0010] Embodiment 7. The microcatheter for local drug delivery according to Embodiment 1, wherein the side fenestrations are provided at the proximal end of the fenestration segment, and there are 2 to 12 side fenestrations along the circumferential direction of the catheter.

[0011] Embodiment 8. The microcatheter for local drug delivery according to Embodiment 1, wherein the arch height of the arcuate profile is 2mm to 40mm, and the span of the arcuate profile is 2mm to 60mm.

[0012] Embodiment 9. The microcatheter for local drug delivery according to Embodiment 1, wherein the microcatheter further comprises a syringe adapter segment at the proximal end, and the outer diameter of the syringe adapter segment is less than or equal to 5.5F.

[0013] Embodiment 10. The microcatheter for local drug delivery according to Embodiment 9, wherein the syringe adapter segment is made of polycarbonate material, and the delivery segment, the fixation segment and the fenestration segment comprise a metal wire inner layer and a polycarbonate skin layer.

[0014] Embodiment 11. A microcatheter for local administration, comprising, in order from proximal to distal end, a delivery segment, a fenestrated segment, a fixation segment and a tip segment, the delivery segment and the fenestrated segment having a continuous inner lumen, an outer diameter of 1.5F to 5F, and an inner diameter of 0.40mm to 1.5mm; the tip segment being substantially straight, having a length of 1 to 40mm; the fixation segment having a preformed arcuate shape for relative fixation between the microcatheter and the vessel by shape after the microcatheter is placed, while the straight tip segment is free in the vessel; the fenestrated segment having a closed end so that the fenestrated segment is not in communication with the tip segment and / or the fixation segment, the fenestrated segment having side fenestrations disposed thereon, and markers disposed near the fenestrated segment, such as at the junction of the fenestrated segment and the fixation segment and / or at the junction of the fenestrated segment and the delivery segment, to assist external devices in detecting its position in the patient; the tip segment and optionally the fixation segment having a guide wire through hole; the outer surface of the microcatheter having an anti-thrombogenic coating.

[0015] Embodiment 12. The microcatheter for local administration according to Embodiment 11, wherein the tip segment has a length of 6mm to 20mm.

[0016] Embodiment 13. The microcatheter for local administration according to Embodiment 11, wherein the delivery segment and the fenestrated segment have an outer diameter of 1.7F to 4F, preferably 1.7 to 2.6F, and an inner diameter of 0.45mm to 1.2mm.

[0017] Embodiment 14. The microcatheter for local administration according to Embodiment 11, wherein the anti-thrombogenic coating is a heparin coating or a heparinoid coating, and optionally the anti-thrombogenic coating is hydrophilic.

[0018] Embodiment 15. The microcatheter for local administration according to Embodiment 11, wherein the inner and outer surfaces of the microcatheter have an anti-thrombogenic coating.

[0019] Embodiment 16. The microcatheter for local administration according to Embodiment 11, wherein the delivery segment has a length of 0.4 to 1.5m, 0.7 to 1.3m, 0.8 to 1.3m, or 1.1 to 1.3m.

[0020] Embodiment 17. The microcatheter for local administration according to Embodiment 11, wherein the side fenestrations are disposed at the proximal end of the fenestrated segment, and there are 2 to 12 of them disposed along the circumference of the catheter.

[0021] Embodiment 18. The microcatheter for local administration according to Embodiment 11, wherein the arcuate shape has a bow height of 2mm to 40mm, and a span of 2mm to 60mm.

[0022] Embodiment 19. The microcatheter for local drug delivery according to embodiment 11, wherein the microcatheter further comprises a proximal syringe adapter segment having an outer diameter of 5.5F or less.

[0023] Embodiment 20. The microcatheter for local drug delivery according to embodiment 19, wherein the syringe adapter segment is made of polycarbonate material, and the delivery segment and the fenestrated segment comprise a wire inner layer and a polycarbonate skin layer.

[0024] Embodiment 21. A medical device for local drug delivery comprising a guide catheter, a guide wire, an auxiliary catheter, and a microcatheter according to any one of embodiments 1-20, wherein the outer diameter of the guide wire is less than the inner diameter of the guide wire lumen, the outer diameter of the auxiliary catheter is greater than the inner diameter of the proximal end of the microcatheter, the inner diameter of the guide catheter is greater than the outer diameter of the microcatheter, such that the guide catheter can be withdrawn with the aid of the auxiliary catheter after being used to help place the guide wire and the microcatheter, leaving the microcatheter in the human body.

[0025] Embodiment 22. The medical device for local drug delivery according to embodiment 21, wherein the outer diameter of the auxiliary catheter is less than the inner diameter of the guide catheter.

[0026] Embodiment 23. A medical device for local drug delivery comprising a guide catheter, a guide wire, an auxiliary wire, and a microcatheter according to any one of embodiments 1-20, wherein the outer diameter of the guide wire is less than the inner diameter of the guide wire lumen, the outer diameter of the auxiliary wire is greater than the inner diameter of the proximal end of the microcatheter, the inner diameter of the guide catheter is greater than the outer diameter of the microcatheter, such that the guide catheter can be withdrawn with the aid of the auxiliary wire after being used to help place the guide wire and the microcatheter, leaving the microcatheter in the human body.

[0027] Embodiment 24. The medical device for local drug delivery according to embodiment 23, wherein the outer diameter of the auxiliary wire is less than the inner diameter of the guide catheter.

[0028] Embodiment 25. The medical device for local drug delivery according to embodiment 23, wherein the distal end of the auxiliary wire has an extended head portion having an outer diameter less than the inner diameter of the proximal end of the microcatheter, such that the auxiliary wire can be inserted into the proximal end of the microcatheter through the extended head portion.

[0029] The microcatheter has a size that can reduce the amount of drug to less than one-tenth of the conventional amount, avoid the influence on other organs of the body caused by excessive drug administration, and does not affect the operation of other organs. The microcatheter is relatively fixed between the body and the blood vessel for a long time, has little displacement, little damage to the intima of the blood vessel, does not form a thrombus in the vein within 24 hours, and is not prone to form a thrombus in the artery for a long time. The microcatheter is suitable for local drug administration for patients with head, liver, and coronary artery diseases, is suitable for local chemotherapy drug administration for cancer patients, and reduces the damage of chemotherapy drugs to other parts and organs of the body. For example, the microcatheter is particularly suitable for surgical treatment of gastrointestinal bleeding in patients with coronary artery diseases, that is, during gastrointestinal bleeding, anticoagulant drugs are not taken, but local anticoagulant drug administration is performed through the microcatheter, and surgical or drug treatment is performed on the gastrointestinal bleeding, and after complete hemostasis, anticoagulant drugs are taken orally, and the microcatheter is removed. For another example, the microcatheter is particularly suitable for local anticoagulant drug administration during surgery for pulmonary diseases accompanied by heart diseases, greatly reduces the risk of surgery, and is also suitable for local drug administration in other cases. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only related to some embodiments of the present disclosure, and not limited to the present disclosure.

[0031] Figure 1 A schematic view of the microcatheter for local drug administration in Example 1;

[0032] Figure 2 A partial schematic view of the microcatheter for local drug administration in Example 1;

[0033] Figure 3 A schematic view of the microcatheter for local drug administration in Example 2;

[0034] Figure 4 A partial schematic view of the microcatheter for local drug administration in Example 2;

[0035] Figures 5 to 10 A schematic view of the microcatheter for local drug administration in Example 2;

[0036] Figure 11 A schematic view of the microcatheter for local drug administration in Example 3.

[0037] BRIEF DESCRIPTION OF DRAWINGS: 10 - microcatheter, 100 - delivery segment, 110 - lumen, 200 - fixation segment, 300 - fenestration segment, 310 - side fenestrations, 320 - marker, 400 - tip segment, 500 - syringe pump adapter segment, 600 - guidewire, 610 - guidewire through hole, 700 - guide tube, 800 - auxiliary tube (auxiliary wire). DETAILED DESCRIPTION

[0038] In order to make the objects, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions of the embodiments of the present disclosure will be described clearly and completely below with reference to the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are some but not all of the embodiments of the present disclosure. Based on the described embodiments of the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the scope of protection of the present disclosure.

[0039] The present application provides a microcatheter for local administration, which comprises, from proximal end to distal end, a delivery segment, a fixation segment, a fenestrated segment and a terminal segment, the delivery segment, the fixation segment and the fenestrated segment have a continuous inner cavity, the outer diameter is 1.5F to 5F, and the inner diameter is 0.40mm to 1.5mm; the length of the terminal segment is 1 to 40mm (for example, 2mm to 35mm, 4mm to 30mm, 6mm to 25mm), and a guide wire through hole is arranged; the fixation segment has a preformed arc shape, which is used to relatively fix the position between the microcatheter and the blood vessel by shape after the microcatheter is arranged; the end of the fenestrated segment is blocked, so that the fenestrated segment is not continuous with the terminal segment, a side opening is arranged on the fenestrated segment, and a marker is arranged near the fenestrated segment, for example, a marker is arranged at the joint of the fenestrated segment and the fixation segment, to help external equipment detect the position in the patient's body; and an anticoagulant coating is arranged on the outer surface of the microcatheter. The division between each segment of the microcatheter in the present application is not completely fixed, because there is also mutual overlap between the functions of these segments. For example, although the fixation segment has the function of fixing the microcatheter and the blood vessel, it still has the function of the delivery segment between the segments with continuous inner cavities. For example, the boundary between the fenestrated segment and the fixation segment can not be particularly clear. However, generally speaking, the starting position of the fenestrated segment can be the opening, and the ending position of the fenestrated segment can be the blocking position. The starting position of the fixation segment can be the starting position of the arc shape, and the ending position can be the ending position of the arc shape. The division of the starting position and the ending position of the fixation segment can also be appropriately adjusted according to the division of the two segments connected before and after it, and there is no particular explicit limitation, as long as the function can achieve the required purpose or achieve the required effect. Similarly, the division of other segments can also be divided according to the actual situation and the function to be achieved. In addition, those skilled in the art should understand that the microcatheter described in the present application is flexible, the shape described in the present application is the similar shape exhibited by the microcatheter in the natural state, and the shape that can be achieved according to the understanding of those skilled in the art. The overall shape of the microcatheter is adapted to the blood vessel path implanted in the body, which can more conveniently implant the microcatheter into the target area and adapt to long-term placement in the blood vessel, for example, the microcatheter for local administration of the coronary artery, the angle between the delivery segment and the terminal segment and / or the fenestrated segment is about 70-120 degrees (for example, about 90 degrees), which can more smoothly reach and place in the coronary artery, and for example, the microcatheter for local administration of the liver or head blood vessel, the delivery segment, the fenestrated segment and the terminal segment are basically straight in the axial direction of the microcatheter. Those skilled in the art can reasonably set the overall shape of the microcatheter according to the implantation area.

[0040] The unit F in the present application has the meaning commonly understood by those skilled in the art, 1F refers to the circumference of the microcatheter is 1 millimeter, 1.5F refers to the circumference of the microcatheter is 1.5 millimeter, 4F refers to the circumference of the microcatheter is 4.0 millimeter. In the present application, "the outer diameter is 1.5F to 5F" refers to the outer diameter when the circumference is 1.5F to 5F. The outer shape of the microcatheter described in the present application can be placed in the body for a long time to give medicine locally through the blood vessels, and is suitable for, for example, the head, liver, coronary artery area, and can be retained in the patient's body for a long time during surgery. The outer diameter of the microcatheter described in the present application is 1.5F to 5F, which allows the microcatheter to be placed in the body for a long time without causing hemolysis and other adverse reactions; the delivery segment, the fixed segment and the opening segment of the microcatheter have a through inner cavity, and the inner diameter is 0.40mm to 1.5mm, which allows the microcatheter to be given through a high-pressure injection pump tube; the distal end segment is provided with a guide wire through hole, which can accommodate a guide wire for microcatheter placement and be free in the blood vessel. The preformed arc-shaped outer shape has a bow height of 2mm to 40mm, and a span of 2mm to 60mm, which can be selected according to the need for setting the blood vessel, for example, the preformed arc-shaped outer shape has a bow height of 2mm to 35mm, or 4mm to 30mm, or 8mm to 25mm, or 2mm to 12mm, for example, the preformed arc-shaped outer shape has a span of 2mm to 50mm, or 4mm to 50mm, or 8mm to 45mm, or 12mm to 40mm, or 20mm to 35mm, or 2mm to 12mm, which relatively fixes the microcatheter in the blood vessel, so that the microcatheter does not displace, has little damage to the intima of the blood vessel when placed in the body for a long time, and does not affect the blood flow, facilitating local administration. The side openings on the opening segment are communicated with the inner cavity, and the opening segment and the distal end segment are not communicated, so that the medicine in the inner cavity can reach the target area through the side openings, and too many side openings can easily lead to the diffusion of the medicine. The number of side openings should not be too many, and those skilled in the art can reasonably set the number of side openings in combination with the range of the target area for administration, for example, 2 to 12, or 2 to 4, or one every 120° on the outer periphery of the opening segment along the circumferential direction of the catheter, that is, 3 side openings are arranged on the outer periphery of the opening segment. In order to accurately position, a marker (marker material) is arranged between the fixed segment and the opening segment, which is used to help external equipment detect its position in the patient's body. The applicant of the present application unexpectedly found that the size of the microcatheter can reduce the amount of administration to less than one tenth of the conventional amount of administration, avoiding the influence on other organs of the body caused by excessive administration. The microcatheter placed in the vein for 24 hours does not thrombose, and placed in the artery for a long time is not easy to thrombose, which is suitable for local administration of patients with head, liver, coronary artery diseases through blood vessels, and is suitable for local administration of cancer patients for chemotherapy, reducing the damage of chemotherapy drugs to other parts and organs of the body.The microcatheter is particularly suitable for surgical treatment of gastrointestinal bleeding in patients with coronary artery disease, i.e. without taking anticoagulants during gastrointestinal bleeding, but through local anticoagulant administration by the microcatheter described in the present application, and surgical treatment of gastrointestinal bleeding. It is particularly suitable for patients with malignant tumors combined with coronary heart disease. After coronary intervention, local coronary anticoagulant administration can safely synchronize tumor resection surgery. It is also suitable for local administration in other situations.

[0041] In some embodiments, the tip section has a length of 6 mm to 20 mm. The appropriate length of the tip section facilitates guiding the catheter through the guide wire to the target area. The specific shape of the tip section is not limited, and in some embodiments, the tip section is straight and free in the blood vessel in the use state. Generally, in order to accurately position, a marker (marker material) is provided near the opening section, which helps external equipment to detect its position in the patient's body. The profile of the microcatheter is suitable for local administration through the blood vessels, such as the head, liver, and coronary artery region of the heart, and remains in the patient's body for a long time (such as more than 24 hours, or even 3-12 days) during surgery.

[0042] In some embodiments, the outer diameter of the delivery section, the fixation section and the opening section is 1.7F to 4F, preferably 1.7 to 2.6F, and the inner diameter is 0.45 mm to 1.2 mm. Such size design neither affects blood circulation in the body nor easily forms thrombus, and can better achieve the effect of local administration.

[0043] In some embodiments, the anticoagulant coating is a heparin coating or a heparinoid coating, and optionally the anticoagulant coating is hydrophilic. By coating the outer surface of the microcatheter with a heparin or heparinoid anticoagulant coating, thrombosis can be effectively prevented, and the effect of local anticoagulation can be achieved.

[0044] In some embodiments, the inner and outer surfaces of the microcatheter are provided with an anticoagulant coating. By coating the inner and outer surfaces of the microcatheter with an anticoagulant coating and soaking the microcatheter in an anticoagulant, blood coagulation can be avoided to the greatest extent.

[0045] In some embodiments, the length of the delivery section is 0.4 to 1.5 m. Such length setting makes the microcatheter widely applicable to coronary artery local administration, liver cancer chemotherapy local administration, and intravenous local administration.

[0046] In some embodiments, the length of the delivery section is 0.7 to 1.3 m, 0.8 to 1.3 m. Such length setting makes the microcatheter particularly suitable for coronary artery local administration.

[0047] In some embodiments, the length of the delivery segment is 1.1 to 1.3 m. Such length setting makes the microcatheter particularly suitable for use in local drug delivery in coronary arteries.

[0048] In some embodiments, the side holes are arranged at the proximal end of the perforation segment, and there are 2 to 12 side holes arranged along the circumferential direction of the catheter. The proximal end of the perforation segment is the starting point of the perforation segment, and the distance between the side holes and the distal end of the microcatheter (i.e. the farthest end of the microcatheter) is less than 40 mm, for example less than 20 mm.

[0049] In some embodiments, the arch height of the arc-shaped profile is 2 mm to 40 mm, and the span of the arc-shaped profile is 2 mm to 60 mm.

[0050] In some embodiments, the microcatheter further comprises a proximal injection pump connector segment, and the outer diameter of the injection pump connector segment is less than or equal to 5.5F, for example 1.5F to 5F. The injection pump connector segment can be connected to a high-pressure injection pump tube, so that the drug solution can pass through the through lumen of the microcatheter to reach the local drug delivery area.

[0051] In some embodiments, the injection pump connector segment is made of polycarbonate material, and the delivery segment, the fixation segment and the perforation segment comprise a metal wire inner layer and a polycarbonate skin layer.

[0052] The present application also provides a microcatheter for local drug delivery, which comprises, from proximal to distal, a delivery segment, a perforation segment, a fixation segment and a distal segment. The delivery segment and the perforation segment have a through lumen, and the outer diameter is 1.5F to 5F, and the inner diameter is 0.40 mm to 1.5 mm. The distal segment is substantially straight, and the length is 1 to 40 mm (for example 2 mm to 35 mm, 4 mm to 30 mm, 6 mm to 25 mm). The fixation segment has a pre-formed arc-shaped profile (the arch height of the arc-shaped profile is 2 mm to 40 mm, and the span of the arc-shaped profile can be 2 mm to 60 mm, which is selected according to the setting of the blood vessel), which is used to relatively fix the position between the microcatheter and the blood vessel by shape after the microcatheter is set, and the straight distal segment is free in the blood vessel. The end of the perforation segment is blocked, so that the perforation segment is not in communication with the distal segment and / or the fixation segment. The perforation segment is provided with side holes (the number of side holes should not be too many, for example 2 to 12 side holes are arranged along the circumferential direction of the catheter on the outer periphery of the perforation segment, or 2 to 4 side holes, or one side hole every 120° on the outer periphery of the perforation segment, which is arranged at the starting segment of the perforation segment), and a marker is arranged near the perforation segment, such as at the connection between the perforation segment and the fixation segment and / or at the connection between the perforation segment and the delivery segment, to help external equipment detect its position in the patient's body. The distal segment and optionally the fixation segment are provided with a guide wire through hole. The outer surface of the microcatheter is provided with an anticoagulant coating.

[0053] The microcatheter described in the present application has an outer shape that can be placed in the body for a long time for local drug delivery through blood vessels, suitable for areas such as the head, liver, and coronary artery area, and can be retained in the patient's body for a long time during surgery. The outer diameter of the microcatheter described in the present application is 1.5F to 5F, which allows the microcatheter to be placed in the body for a long time without causing hemolysis and other adverse reactions; the delivery segment and the opening segment of the microcatheter have a through inner cavity, and the inner diameter is 0.40mm to 1.5mm, which allows the microcatheter to be administered through a high-pressure injection pump tube. The distal segment and the optional fixed segment are provided with a guide wire through hole, which can accommodate a guide wire for catheter placement and be free in the blood vessel. The pre-formed arc-shaped outer shape has a bow height of 2mm to 40mm, and a span of 2mm to 60mm, which can be selected according to the need for setting the blood vessel, for example, the pre-formed arc-shaped outer shape has a bow height of 2mm to 35mm, or 4mm to 30mm, or 8mm to 25mm, or 2mm to 12mm, for example, the pre-formed arc-shaped outer shape has a span of 2mm to 50mm, or 4mm to 50mm, or 8mm to 45mm, or 12mm to 40mm, or 20mm to 35mm, or 2mm to 12mm, which relatively fixes the microcatheter in the blood vessel, prevents displacement of the microcatheter, and does not affect blood flow, facilitating local drug delivery. When the fixed segment is provided with a guide wire through hole, the shape of the fixed segment is consistent with the shape of the guide wire when the microcatheter enters the blood vessel along the guide wire, facilitating implantation, and after the guide wire is withdrawn, the fixed segment resumes an arc shape, relatively fixing the position between the microcatheter and the blood vessel. The side openings on the opening segment are in communication with the inner cavity, and the opening segment is not in communication with the distal segment and / or the fixed segment, so that the drug in the inner cavity can reach the target area through the side openings. Too many side openings can easily lead to a decrease in the strength of the microcatheter, and the number of side openings should not be too large. Those skilled in the art can reasonably set the number of side openings in combination with the range of the target area for drug delivery, for example, 2 to 12 along the circumferential direction of the catheter, for example, one every 120° on the outer periphery of the opening segment, that is, three side openings are provided on the outer periphery of the opening segment. In order to accurately position, a marker (marker material) is provided between the fixed segment and the opening segment and / or between the opening segment and the delivery segment, which is used to help external equipment detect its position in the patient's body. The applicant of the present application unexpectedly found that the size of the microcatheter can reduce the amount of drug to less than one tenth of the conventional amount, avoiding the influence on other organs of the body caused by excessive drug administration. The microcatheter placed in the vein for 24 hours does not thrombose, and placed in the artery for a long time is not prone to thrombosis, suitable for local drug delivery through blood vessels for patients with head, liver, and coronary artery diseases, suitable for local chemotherapy drug delivery for cancer patients, and reducing the damage of chemotherapy drugs to other parts and organs of the body.The microcatheter is particularly suitable for surgical treatment of gastrointestinal bleeding in patients with coronary artery disease, i.e. without taking anticoagulants during gastrointestinal bleeding, but through the microcatheter described in the application for local anticoagulant administration, and surgical treatment of gastrointestinal bleeding. It is particularly suitable for local anticoagulant administration during surgery for pulmonary disease accompanied by heart disease, which greatly reduces the risk of surgery during the operation. It is also suitable for local administration in other situations.

[0054] In some embodiments, the length of the tip section is 6mm to 20mm. The appropriate length of the tip section facilitates the guiding of the catheter through the guide wire to the target area.

[0055] In some embodiments, the outer diameter of the delivery section and the opening section is 1.7F to 4F, preferably 1.7 to 2.6F, and the inner diameter is 0.45mm to 1.2mm. Such size design neither affects the blood circulation in the body nor easily forms thrombus, and can better achieve the effect of local administration.

[0056] In some embodiments, the anticoagulant coating is a heparin coating or a heparin-like coating, and optionally the anticoagulant coating is hydrophilic. By coating the outer surface of the microcatheter with a heparin or heparin-like anticoagulant coating, thrombosis can be effectively prevented, achieving the effect of local anticoagulation.

[0057] In some embodiments, the inner and outer surfaces of the microcatheter are provided with an anticoagulant coating. By coating the inner and outer surfaces of the microcatheter with an anticoagulant coating and soaking the microcatheter in an anticoagulant, blood coagulation can be avoided to the greatest extent.

[0058] In some embodiments, the length of the delivery section is 0.4 to 1.5m. Such length setting makes the microcatheter widely applicable to coronary artery local administration, liver cancer chemotherapy local administration, and intravenous local administration.

[0059] In some embodiments, the length of the delivery section is 0.7 to 1.3m, 0.8 to 1.3m. Such length setting makes the microcatheter particularly suitable for coronary artery local administration.

[0060] In some embodiments, the length of the delivery section is 1.1 to 1.3m. Such length setting makes the microcatheter particularly suitable for coronary artery local administration.

[0061] In some embodiments, the side openings are arranged at the proximal end of the opening section, and there are 2 to 12 side openings arranged along the circumferential direction of the catheter. The proximal end of the opening section is the starting position of the opening section, and the distance between the side openings and the tip of the microcatheter (i.e. the farthest end of the microcatheter) is less than 60mm, for example less than 40mm, for example less than 20mm.

[0062] In some embodiments, the arcuate profile has a bow height of 2 mm to 40 mm and a span of 2 mm to 60 mm.

[0063] In some embodiments, the microcatheter further comprises a proximal injection pump hub segment having an outer diameter of 5.5F or less, such as 1.5F to 5F. The injection pump hub segment is capable of connecting to a high pressure injection pump tube to deliver a liquid drug through the lumen of the microcatheter to the local administration site.

[0064] In some embodiments, the injection pump hub segment is made of polycarbonate material, and the delivery segment and the fenestration segment comprise a wire inner layer and a polycarbonate outer layer.

[0065] The present application also discloses a medical device for local administration, which comprises a guiding catheter, a guide wire, an auxiliary tube and the microcatheter as described above, wherein the inner diameter of the auxiliary tube is smaller than the outer diameter of the proximal end of the microcatheter, the outer diameter of the guide wire is smaller than the inner diameter of the guide wire through hole, the outer diameter of the auxiliary tube is larger than the inner diameter of the proximal end of the microcatheter, and the inner diameter of the guiding catheter is larger than the outer diameter of the microcatheter, so that the guiding catheter can be withdrawn with the help of the auxiliary tube after being used to help set the guide wire and the microcatheter, leaving the microcatheter in the human body. When the guiding catheter is withdrawn, the proximal end of the microcatheter is pressed against the auxiliary tube outside the body, so that the guiding catheter can be withdrawn without affecting the position of the microcatheter in the body. In addition, the guide wire can also be withdrawn with the help of the auxiliary tube without affecting the position of the microcatheter in the body after the proximal end of the microcatheter is pressed against the auxiliary tube outside the body.

[0066] In some embodiments, the outer diameter of the auxiliary tube is smaller than the inner diameter of the guiding catheter. At this time, the auxiliary tube can enter the guiding catheter, and the guiding catheter can be withdrawn along the auxiliary tube.

[0067] The present application also discloses a medical device for local administration, which comprises a guiding catheter, a guide wire, an auxiliary wire and the microcatheter as described above, wherein the outer diameter of the guide wire is smaller than the inner diameter of the guide wire through hole, the outer diameter of the auxiliary wire is larger than the inner diameter of the proximal end of the microcatheter, and the inner diameter of the guiding catheter is larger than the outer diameter of the microcatheter, so that the guiding catheter can be withdrawn with the help of the auxiliary wire after being used to help set the guide wire and the microcatheter, leaving the microcatheter in the human body. When the guiding catheter is withdrawn, the proximal end of the microcatheter is pressed against the auxiliary wire outside the body, so that the guiding catheter can be withdrawn without affecting the position of the microcatheter in the body. In addition, the guide wire can also be withdrawn with the help of the auxiliary wire without affecting the position of the microcatheter in the body after the proximal end of the microcatheter is pressed against the auxiliary wire outside the body.

[0068] In some embodiments, the outer diameter of the auxiliary wire is smaller than the inner diameter of the guide tube. In this case, the auxiliary wire can be inserted into the guide tube, and the guide tube can be withdrawn along the auxiliary wire.

[0069] In some embodiments, the distal end of the auxiliary wire has an extended head with an outer diameter smaller than the inner diameter of the proximal end of the microcatheter, so that the auxiliary wire can be inserted into the proximal end of the microcatheter through the extended head.

[0070] The method for preparing the microcatheter described in the present application is not particularly required, and can be prepared by a method known to those skilled in the art. The strength of the microcatheter is not particularly required, and can be the strength of the microcatheter generally used in the art, and can be adjusted according to the actual situation.

[0071] The microcatheter described in the present application is relatively fixed between the body and the blood vessel for a long time, has little displacement, and has little damage to the intima of the blood vessel. It does not form thrombus in the vein within 24 hours, and does not easily form thrombus in the artery for a long time. It is suitable for local administration to patients with head, liver, and coronary artery diseases through the blood vessel in the body, and is suitable for local administration of chemotherapy to cancer patients. Local administration using it can reduce the administration amount to less than one tenth of the conventional administration amount, avoid the adverse effects of excessive administration on other organs of the body, and does not affect the surgery of other organs.

[0072] The above-mentioned ranges can be used alone or in combination. The present application can be more easily understood through the following examples.

[0073] Example

[0074] Example 1

[0075] This example discloses a microcatheter for local administration, as shown in Figure 1 and Figure 2 which comprises, in order from the proximal end to the distal end, a delivery section 100, a fixed section 200, a perforated section 300, and a terminal section 400. The length of the delivery section 100 is 1.1 m, and the delivery section 100, the fixed section 200, and the perforated section 300 have a continuous inner cavity 110 with an outer diameter of 4F and an inner diameter of 1.0 mm. This size allows the microcatheter to be placed in the body for a long time without causing hemolysis and other adverse reactions, and to be administered through a high-pressure injection pump tube.

[0076] The length of the terminal segment 600 is 10 mm, which is provided with a guide wire through hole 610, which can accommodate the guide wire for microcatheter setting and be free in the blood vessel. The fixed segment 200 has a preformed arc-shaped profile, the arch height of the arc-shaped profile is 4 mm, and the span of the arc-shaped profile is 20 mm, which is used to relatively fix the position between the microcatheter and the blood vessel by shape after the microcatheter is set, so that the microcatheter does not displace, and does not affect the blood flow, and facilitates local administration. The end of the opening segment 300 is blocked, so that the opening segment 300 is not communicated with the terminal segment 400, and three side openings 310 are provided on the outer periphery of the opening segment 300, so that the drug in the inner cavity 110 can reach the target area through the side openings 310. A marker 320 is provided at the connection between the opening segment 300 and the fixed segment 200, which is used to help the external equipment detect its position in the patient's body. The delivery segment 100, the fixed segment 200 and the opening segment 300 contain a metal wire inner layer and a polycarbonate skin layer, and the outer surface of the microcatheter is provided with a hydrophilic heparin anticoagulant coating.

[0077] The microcatheter does not thrombose within 24 hours after being placed in the vein, and is not easy to thrombose for a long time after being placed in the artery, and is suitable for local administration to patients with head, liver and coronary artery diseases through blood vessels, is suitable for local administration of chemotherapy to cancer patients, and can reduce the amount of administration to less than one tenth of the conventional amount of administration, thereby reducing the damage of chemotherapy drugs to other parts of the body and organs.

[0078] Embodiment 2

[0079] The embodiment discloses a medical device for local administration of coronary artery, referring to Figures 3 to 10 which comprises a guide tube 700, a guide wire 600, an auxiliary wire 800 and a microcatheter 10. The microcatheter 10 comprises, from proximal end to distal end, an injection pump connector segment 500, a delivery segment 100, an opening segment 300, a fixed segment 200 and a terminal segment 400. The length of the delivery segment 100 is 1.3 m, the injection pump connector segment 500, the delivery segment 100 and the opening segment 300 have a communicating inner cavity 110, the outer diameter of the injection pump connector segment is 3.5F, the outer diameter of the delivery segment 100 and the opening segment 300 is 2.6F, and the inner diameter of the inner cavity 110 is 0.6 mm; the terminal segment 400 is basically straight, the length is 10 mm, and can be free in the blood vessel, facilitating microcatheter implantation. The size enables the microcatheter to be placed in the body for a long time without causing hemolysis reaction and other adverse reactions, and can be administered by a high-pressure injection pump tube. The injection pump connector segment 500 is made of polycarbonate material, and the delivery segment 100 and the opening segment 300 contain a metal wire inner layer and a polycarbonate skin layer.

[0080] The fixing section 200 has a pre-formed arc shape with a height of 4 mm and a span of 20 mm. This arc shape fixes the microcatheter relatively within the blood vessel, preventing displacement of the microcatheter while maintaining blood flow, thus facilitating local drug delivery. The overall shape of the microcatheter is as follows: Figure 3 As shown, the delivery section 100 and the terminal section 400 of the microcatheter form an angle of approximately 90 degrees, which allows for smoother delivery and placement in the coronary artery.

[0081] Reference Figure 4 The end of the opening section 300 near the fixed section 200 is blocked, so that the opening section 300 is not connected to the end section 400 and the fixed section 200. A side opening 310 is provided every 120° on the starting section of the opening section 300, so that the drug in the inner cavity 110 can reach the target area through the side opening 310.

[0082] Markers 320 are provided at the connection between the opening section 300 and the fixing section 200 and at the connection between the opening section 300 and the conveying section 100 to help external devices detect their position in the patient's body;

[0083] The distal segment 400 and the fixed segment 200 are provided with guidewire through holes 610, which can accommodate guidewires for catheter placement. When the microcatheter enters the blood vessel along the guidewire, the shape of the fixed segment 200 is consistent with the shape of the guidewire, which facilitates implantation. After the guidewire is withdrawn, the fixed segment 200 returns to an arc shape, so that the position between the microcatheter and the blood vessel is relatively fixed.

[0084] The microcatheter has a hydrophilic heparin anticoagulant coating on both its inner and outer surfaces. When placed in a vein, the microcatheter does not form thrombi within 24 hours; when placed in an artery, it is unlikely to form thrombi even with prolonged placement. It is suitable for local drug delivery in patients with coronary artery disease, reducing the dosage to less than one-tenth of the conventional dosage and minimizing damage to other parts of the body and organs.

[0085] Figures 5 to 10 A schematic diagram of a microcatheter implanted in vivo using a medical device for local drug delivery is shown, wherein the outer diameter of the guidewire 600 is smaller than the inner diameter of the guidewire through-hole 610, the outer diameter of the auxiliary wire 800 is larger than the inner diameter of the nearest end of the microcatheter 10, the outer diameter of the auxiliary wire 800 is smaller than the inner diameter of the guide tube 700, and the inner diameter of the guide tube 700 is larger than the outer diameter of the microcatheter 10.

[0086] like Figure 5 As shown, first, guide wire 600 is set in the target area, and guide tube 700 is pushed to the target area, as follows. Figure 6 As shown, the microcatheter 10 is pushed to the target area along the guidewire 600. Figure 7 It showsFigure 6 Partial view of the microcatheter in the dashed box. As shown in Figure 8 the distal end of the auxiliary wire 800 has an extended head, the outer diameter of which is smaller than the inner diameter of the proximal end of the microcatheter 10, so that the auxiliary wire 800 can be inserted into the proximal end of the microcatheter through the extended head, ensuring that the auxiliary wire 800 can be stably abutted against the proximal end of the microcatheter 10, and the proximal end of the microcatheter 10 is abutted against by the auxiliary wire 800 in vitro, as shown in Figure 9 and Figure 10 the guide tube 700 and the guide wire 600 can be withdrawn with the help of the auxiliary wire 800 without affecting the in-vivo position of the microcatheter 10. After the guide wire is withdrawn, the fixed segment resumes the arc shape, which enables the microcatheter to be stably arranged at the coronary artery without causing too much displacement and affecting the blood flow. Through the high-pressure injection pump tube connected to the injection pump joint segment, the drug reaches the target area directly through the inner cavity of the microcatheter, realizing local administration, and the administration amount can be reduced to less than one-tenth of the conventional administration amount.

[0087] Embodiment 3

[0088] The embodiment discloses a microcatheter for local administration of cerebral vessels, which comprises, from proximal end to distal end, an injection pump joint segment, a delivery segment, a perforated segment, a fixed segment and a terminal segment. The length of the delivery segment is 1.1 m, the injection pump joint segment, the delivery segment and the perforated segment have a communicating inner cavity, the outer diameter of the injection pump joint segment is 5.5F, the outer diameter of the delivery segment and the perforated segment is 4F, and the inner diameter of the inner cavity is 1.2 mm; the terminal segment is basically straight, with a length of 2 mm, and can be free in the blood vessel, facilitating microcatheter implantation, and the size enables the microcatheter to be placed in the body for a long time without causing hemolysis and other adverse reactions and enables the microcatheter to be administered through a high-pressure injection pump tube, wherein the injection pump joint segment is made of polycarbonate material, and the delivery segment and the perforated segment comprise a metal wire inner layer and a polycarbonate skin layer.

[0089] The overall shape of the microcatheter is shown in Figure 11 the delivery segment 100, the perforated segment 300 and the terminal segment 400 are basically straight in the axial direction of the microcatheter, the fixed segment 200 has a preformed arc-shaped outer shape, the arch height of the arc-shaped outer shape is 2 mm, and the span is 10 mm, the arc-shaped outer shape relatively fixes the microcatheter in the blood vessel, so that the microcatheter does not displace and does not affect the blood flow, and local administration is facilitated.

[0090] The end of the perforated segment close to the fixed segment is blocked, so that the perforated segment is not communicated with the terminal segment and the fixed segment, and a side opening is arranged on the initial segment of the perforated segment, which is about 20 mm away from the terminal end of the microcatheter, so that the drug in the inner cavity can reach the target area through the side opening.

[0091] A marker is arranged at the connection between the opening section and the fixed section and the connection between the opening section and the delivery section to help the external device detect its position in the patient's body.

[0092] The tip section and the fixed section are provided with a guide wire through hole to accommodate a guide wire for catheterization, and when the microcatheter enters the blood vessel along the guide wire, the shape of the fixed section is consistent with that of the guide wire, facilitating implantation, and after the guide wire is withdrawn, the fixed section restores to an arc shape, relatively fixing the position between the microcatheter and the blood vessel, and the displacement of the microcatheter is very small, without damaging the intima of the blood vessel and affecting the blood flow.

[0093] The inner and outer surfaces of the microcatheter are provided with a hydrophilic heparin anticoagulant coating, which is not easy to form thrombus when placed in the cerebral blood vessel. When a stent is implanted in the cerebral blood vessel or anticoagulant therapy is performed for cerebral infarction, the microcatheter is selectively placed in the cerebral blood vessel (the diameter of the cerebral blood vessel is 2-4 mm), and the injection pump connector section is fixed and connected to an anticoagulant drug outside the body, continuously pumping the anticoagulant or antiplatelet drug. Because of selective infusion, the drug dosage can be reduced to 1 / 20-1 / 10 of the systemic dosage. For patients with bleeding and bleeding tendency, 2-15 days of non-anticoagulant / antiplatelet therapy time can be obtained.

[0094] Embodiment 4

[0095] The embodiment discloses a microcatheter for local administration of the liver, which comprises, from proximal to distal, an injection pump connector section, a delivery section, an opening section, a fixed section and a tip section. The length of the delivery section is 1.2 m, the injection pump connector section, the delivery section and the opening section have a communication inner cavity, the outer diameter of the injection pump connector section is 5.5F, the outer diameter of the delivery section and the opening section is 5F, and the inner diameter of the inner cavity is 1.5 mm; the tip section is basically straight, with a length of 20 mm, and can be free in the blood vessel, facilitating microcatheter implantation, and the size enables the microcatheter to be placed in the body for a long time without causing hemolysis and other adverse reactions, and the microcatheter can be administered by a high-pressure injection pump tube, wherein the injection pump connector section is made of polycarbonate material, and the delivery section and the opening section comprise a metal wire inner layer and a polycarbonate skin layer.

[0096] The overall shape of the microcatheter is consistent with that of embodiment 3, the fixed section has a preformed arc-shaped outer shape, the arch height of the arc-shaped outer shape is 2 mm, and the span is 12 mm, the arc-shaped outer shape relatively fixes the microcatheter in the blood vessel, so that the microcatheter does not displace and the blood flow is not affected, and local administration is facilitated.

[0097] The open hole section is closed near the end of the fixed section, so that the open hole section is not communicated with the terminal section and the fixed section, and the starting section of the open hole section is provided with a side opening, which is about 40mm away from the terminal of the microcatheter, so that the drug in the lumen can reach the target area through the side opening.

[0098] A marker is arranged at the connection between the open hole section and the fixed section and the connection between the open hole section and the delivery section, to help the external device detect its position in the patient's body.

[0099] The terminal section and the fixed section are provided with a guide wire through hole, which can accommodate a guide wire for catheter arrangement, when the microcatheter enters the blood vessel along the guide wire, the shape of the fixed section is consistent with the shape of the guide wire, facilitating implantation, after the guide wire is withdrawn, the fixed section restores to an arc shape, relatively fixing the position between the microcatheter and the blood vessel, the displacement of the microcatheter is very small, without damaging the intima of the blood vessel, and without affecting the blood flow.

[0100] The inner and outer surfaces of the microcatheter are provided with a hydrophilic heparin anticoagulant coating, which is not easy to form thrombus when placed in the hepatic blood vessel. For tumor patients during chemotherapy, such as liver cancer, the microcatheter is selectively placed in the tumor blood supply catheter (select a certain hepatic lobe artery), and selective pumping of chemotherapeutic drugs can achieve the effect of local chemotherapy or selective chemical resection. Because of the selective pumping of drugs, the total dose of chemotherapy can be reduced to 1 / 20-1 / 10 of the original dose, and the side effects of chemotherapy are significantly reduced.

[0101] The above only describes exemplary embodiments of the present disclosure, and is not intended to limit the protection scope of the present disclosure, and the protection scope of the present disclosure is determined by the appended claims.

Claims

1. A microcatheter for local drug delivery, comprising, from proximal to distal: Conveying section, stationary section, perforated section, and end section. The conveying section, fixing section, and opening section have a communicating inner cavity with an outer diameter of 1.5F to 5F and an inner diameter of 0.40 mm to 1.5 mm. The length of the end section is 1 to 40 mm, and it is provided with a guide wire through hole; The fixing section has a pre-formed arc shape, which is used to fix the position between the microcatheter and the blood vessel by means of the shape after the microcatheter is set; The end of the opening section is sealed, thus preventing the opening section from communicating with the end section. The opening section is provided with a side opening, and a marker is placed near the opening section to help external devices detect their position in the patient's body; The outer surface of the microcatheter is provided with an anticoagulant coating; The arc-shaped profile has a bow height of 2mm to 40mm and a span of 8mm to 45mm.

2. The microcatheter for local drug delivery according to claim 1, wherein the length of the distal segment is 6 mm to 20 mm, and wherein the outer diameter of the delivery segment, the fixation segment, and the opening segment is 1.7F to 4F, and the inner diameter is 0.45 mm to 1.2 mm.

3. The microcatheter for local drug delivery according to claim 1, wherein the anticoagulant coating is a heparin coating or a heparin-like coating, the anticoagulant coating is hydrophilic, and the inner and outer surfaces of the microcatheter are provided with an anticoagulant coating.

4. The microcatheter for local drug delivery according to claim 1, wherein the length of the delivery segment is 0.4 to 1.5 m, 0.7 to 1.3 m, 0.8 to 1.3 m, or 1.1 to 1.3 m.

5. The microcatheter for local drug delivery according to claim 1, wherein the side openings are provided at the proximal end of the opening segment, and 2 to 12 are provided along the circumference of the catheter.

6. The microcatheter for local drug delivery according to claim 1, wherein the microcatheter further comprises a proximal infusion pump connector segment, the outer diameter of the infusion pump connector segment being less than or equal to 5.5F.

7. The microcatheter for local drug delivery according to claim 6, wherein the injection pump connector section is made of polycarbonate material, and the delivery section, fixing section and opening section comprise a wire inner layer and a polycarbonate outer layer.

8. The microcatheter for local drug delivery according to claim 1, wherein a marker is provided at the connection between the opening section and the fixing section.

9. The microcatheter for local drug delivery according to claim 2, wherein the outer diameter of the delivery section, the fixation section and the opening section is 1.7 to 2.6F.

10. A microcatheter for local drug delivery, comprising, from proximal to distal: Conveying section, opening section, fixing section, and end section. The conveying section and the opening section have a communicating inner cavity with an outer diameter of 1.5F to 5F and an inner diameter of 0.40 mm to 1.5 mm. The end segment is substantially straight and has a length of 1 to 40 mm; The fixing section has a pre-formed arc shape, which is used to fix the position between the microcatheter and the blood vessel by the shape after the microcatheter is installed, while the straight end section is free in the blood vessel. The end of the opening section is sealed, thereby preventing the opening section from communicating with the end section and / or the fixed section. The opening section is provided with a side opening, and a marker is placed near the opening section to help external devices detect their position in the patient's body; The end section and the fixed section are provided with guide wire through holes; The outer surface of the microcatheter is provided with an anticoagulant coating; The arc-shaped profile has a bow height of 2mm to 40mm and a span of 8mm to 45mm.

11. The microcatheter for local drug delivery according to claim 10, wherein the length of the distal segment is 6 mm to 20 mm, and wherein the outer diameter of the delivery segment and the orifice segment is 1.7F to 4F, and the inner diameter is 0.45 mm to 1.2 mm.

12. The microcatheter for local drug delivery according to claim 10, wherein the anticoagulant coating is a heparin coating or a heparin-like coating, the anticoagulant coating is hydrophilic, and wherein the inner and outer surfaces of the microcatheter are provided with an anticoagulant coating.

13. The microcatheter for local drug delivery according to claim 10, wherein the length of the delivery segment is 0.4 to 1.5 m, 0.7 to 1.3 m, 0.8 to 1.3 m, or 1.1 to 1.3 m.

14. The microcatheter for local drug delivery according to claim 10, wherein the side openings are provided at the proximal end of the opening segment, and 2 to 12 are provided along the circumference of the catheter.

15. The microcatheter for local drug delivery according to claim 10, wherein a marker is provided at the connection between the opening section and the fixing section and / or at the connection between the opening section and the delivery section.

16. The microcatheter for local drug delivery according to claim 11, wherein the outer diameter of the delivery section and the opening section is 1.7 to 2.6F.

17. A medical device for local drug delivery, comprising a guide tube, a guidewire, an auxiliary tube, and a microcatheter according to any one of claims 1-16, wherein the inner diameter of the auxiliary tube is smaller than the outer diameter of the proximal end of the microcatheter, the outer diameter of the guidewire is smaller than the inner diameter of the guidewire through-hole, the outer diameter of the auxiliary tube is larger than the inner diameter of the proximal end of the microcatheter, and the inner diameter of the guide tube is larger than the outer diameter of the microcatheter, such that the guide tube, after being used to assist in the placement of the guidewire and microcatheter, can be withdrawn with the assistance of the auxiliary tube, leaving the microcatheter in the human body.

18. A medical device for local drug delivery, comprising a guide tube, a guidewire, an auxiliary wire, and a microcatheter according to any one of claims 1-16, wherein the outer diameter of the guidewire is smaller than the inner diameter of the guidewire orifice, the outer diameter of the auxiliary wire is larger than the inner diameter of the proximal end of the microcatheter, and the inner diameter of the guide tube is larger than the outer diameter of the microcatheter, such that the guide tube, after being used to assist in the placement of the guidewire and microcatheter, can be withdrawn with the assistance of the auxiliary wire, leaving the microcatheter in the human body.

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