CN111265761A

CN111265761A - Medicine balloon catheter capable of keeping blood supply at far end

Info

Publication number: CN111265761A
Application number: CN202010191278.7A
Authority: CN
Inventors: 杜瑞林; 葛均波; 颜玉强; 陈丽君; 季培红; 杨威
Original assignee: Hangzhou Batai Medical Equipment Co ltd
Current assignee: Hangzhou Batai Medical Equipment Co ltd
Priority date: 2020-03-18
Filing date: 2020-03-18
Publication date: 2020-06-12

Abstract

The utility model provides a can keep medicine sacculus pipe of distal end blood supply, includes tip pipe, sacculus, inner tube and outer tube, the near-end rigid coupling of sacculus is in on the outer tube and its distal end rigid coupling is in on the tip pipe, the inner tube stretches out the outer tube and passes the cavity of sacculus, the distal end of inner tube stretches out the sacculus and with tip pipe intercommunication, still include the blood flow and prevent the block mechanism, the blood flow prevents the block mechanism and is used for in form the process in the medicine sacculus pipe the district section of sacculus place and with the communicating blood flow passageway of blood vessel. When the invention is used for interventional therapy, blood vessels cannot be blocked, distal blood supply is kept through the blood flow passage, and distal ischemia is avoided, so that the invention has longer interventional therapy time, the medicine is fully released, and the blood vessels are not easy to rebound and shrink after the interventional therapy is finished.

Description

Medicine balloon catheter capable of keeping blood supply at far end

Technical Field

The invention relates to the technical field of angioplasty, in particular to a drug balloon catheter capable of keeping blood supply at a far end.

Background

Balloon angioplasty is one of the most common treatments for vascular disease. The traditional balloon angioplasty is often accompanied with the damage of blood vessels, for example, because the diameters of the proximal end and the distal end of the balloon are larger than the diameter of the middle part of the balloon in the process of balloon dilatation, namely a 'dog bone effect', the blood vessels contacted with the two ends of the balloon are over-dilated, the injury of the blood vessel walls is caused, the longitudinal elongation of the balloon is caused to accelerate the vascular dissection (> 30%), and meanwhile, the acute blood vessel occlusion (5% -12%) and the postoperative restenosis (50%) of a diseased part can be caused. Vascular dissection, acute vascular occlusion, and vessel wall injury are all vascular wounds caused by traditional balloon angioplasty.

At present, the traditional balloon angioplasty is optimized by adding tiny blades on the surface of the balloon to form a cutting balloon, and the cutting balloon does show efficacy in clinic, when the cutting balloon is expanded, the blocked blood vessel is opened by cutting and compressing plaque, but the injury of the inner wall of the blood vessel is increased.

Because of the many vascular injuries in the traditional balloon angioplasty, the stent is often used as an initial treatment for vascular diseases, and a drug-eluting stent is often implanted after the later treatment, but the drug-eluting stent still causes complications such as high in-stent restenosis rate.

As a new generation of minimally invasive techniques for treating angiostenosis, a drug-coated balloon dilatation catheter is getting more and more attentions, and the concept of 'intervention without implantation' is gradually deepened into the heart, for example, a patent document with the patent number of CN102939125A discloses an angioplasty balloon which has an elastic restriction structure, when the balloon is expanded, the elastic restriction structure draws a grid area uniformly distributed on the balloon to form a 'pillow' pattern, and the balloon has a limitable expansion shape, so that the vascular injury can be reduced. However, compared with a drug-eluting stent, the drug-coated balloon dilatation catheter has short action time at the lesion site and must be strictly controlled, because once the balloon is propped open at the lesion site, the blood vessel needs to be blocked, blood does not pass through within a short time, and remote ischemia is very easy to cause. Therefore, the conventional drug-coated balloon dilatation catheter generally has short dilatation time, so that the drug is not sufficiently released, and the blood vessel is likely to rebound to the original shape after the balloon is short and withdrawn.

Disclosure of Invention

The invention aims to provide a medicine balloon catheter capable of keeping blood supply at a far end, and aims to solve the problem that the existing interventional medicine coating balloon catheter has poor treatment effect due to blood flow blockage when acting in a blood vessel.

The specific technical scheme of the invention is as follows: the utility model provides a can keep medicine sacculus pipe of distal end blood supply, includes tip pipe, sacculus, inner tube and outer tube, the near-end rigid coupling of sacculus is in on the outer tube and its distal end rigid coupling is in on the tip pipe, the inner tube stretches out the outer tube and passes the cavity of sacculus, the distal end of inner tube stretches out the sacculus and with tip pipe intercommunication, still include the blood flow and prevent the block mechanism, the blood flow prevents the block mechanism and is used for in form the process in the medicine sacculus pipe the district section of sacculus place and with the communicating blood flow passageway of blood vessel. The drug balloon catheter further comprises a hypotube, a catheter reinforcing piece and a catheter seat, wherein the far end of the hypotube is fixedly connected with the near end of the outer tube, the far end of the catheter reinforcing piece is fixedly connected with the near end of the hypotube, and the near end of the catheter reinforcing piece is fixedly connected with the catheter seat.

The traditional medicine balloon catheter has great use defects, namely when the traditional medicine balloon catheter acts in a blood vessel, blood circulation is temporarily blocked due to the expansion of the balloon to the blood vessel, so that far-end ischemia is easily caused, and complications are possibly generated, so that the interventional treatment time of the traditional medicine balloon catheter is actually short and needs to be strictly controlled, the actual release amount of a medicine coating is insufficient and sufficient, the treatment effect is greatly reduced, and the medicine coating is not utilized sufficiently and wasted; and because of the limited treatment time, the dilatation and dredging effect on the blood vessel is not enough, and the blood vessel is easy to rebound and shrink again after being withdrawn. The technical scheme improves the prior medicine balloon catheter, and aims to solve the problem that a blood flow anti-blocking mechanism is designed, and aims to form a blood flow passage inside the medicine balloon catheter, so that even when the balloon is expanded, blood vessels are not blocked, the intervention time limitation of the traditional medicine balloon catheter is removed, the condition of remote ischemia is effectively relieved, the possibility of occurrence of complications is reduced, and the administration time of the medicine balloon is greatly prolonged.

Preferably, the blood flow anti-blocking mechanism comprises a plurality of near-end blood supply holes, a common connecting part is arranged between the inner tube and the outer tube, the near-end blood supply holes are arranged on the common connecting part, the near-end blood supply holes are introduced into the inner tube from the outer tube, and a space between the inner tube and the outer tube, in which the common connecting part is not arranged, is a pressurizing cavity communicated with the inner cavity of the balloon.

Blood passes into the lumen of inner tube from the near-end blood supply hole, namely in the wire guide cavity, through the section that the sacculus is located, and finally follow the mouth of pipe of tip pipe leads to, or in turn lead to and lead to from the mouth of pipe of tip pipe the near-end blood supply hole leads to, has formed the inside blood flow route that traditional medicine sacculus pipe did not possess, does not have the problem that the sacculus expands the blood vessel of temporary blocking promptly, and this interim inside blood flow route allows the medicine sacculus has longer intervention time, and the administration is sufficient, abundant, avoids the long-time ischemia of distal end simultaneously, prevents the production of complication, effectively improves treatment.

Preferably, the liquid inlet angle of the near-end blood supply hole is 0-180 degrees.

The liquid inlet angle of the near-end blood supply hole is the horizontal included angle of the central axis of the pore passage, so that the blood is more easily guided to flow to the far end, and the blood flow resistance is reduced.

Preferably, the inlet angle of the proximal blood supply hole is 45 degrees.

The liquid inlet angle of the near-end blood supply hole is the horizontal included angle of the central axis of the pore passage, and the 45-degree liquid supply hole is set to have a proper effect in consideration of starting points of guiding blood to flow to the far end and reducing blood flow resistance more easily. The inner surface of the proximal feeding hole can be coated with a hydrophilic coating, and the guiding and the resistance can be optimized and reduced.

Preferably, the proximal donor holes are arranged in an array.

The arrangement of the near-end blood supply holes in the array can ensure that the hole opening part is more regular and uniform, thereby reducing the influence of the reduction of the strength of the tube caused by hole opening to the maximum extent, ensuring that the stress of the tube section part with the hole opening is balanced, and preventing the tube from being bent or even broken in the conveying process.

Preferably, the proximal donor holes are arranged in a plurality of staggered rows.

From the angle of reducing the influence that leads to the reduction of tubular product intensity because of the trompil as far as possible, multiseriate near-end blood supply hole staggered arrangement is preferred setting, and the pipeline section atress is more balanced, prevents that buckling, cracked effect are better.

Preferably, the proximal blood supply hole is a hole with a circular or polygonal cross section.

A circular hole is conventionally selected, the forming is simple and convenient, and the diameter is controlled to be 0.05-0.5 mm.

Preferably, a section of the inner tube located before the proximal feeding hole is provided with a feeding hole mark part.

The donor hole mark part is positioned at the near end of the inner tube relative to the near end donor hole, and besides the function of serving as a position reference of the near end donor hole, the donor hole mark part mainly cooperates with a guide wire to play a role in prompting, for example, after the balloon is positioned, the guide wire is withdrawn to the donor hole mark part, the balloon can be started to expand to treat a diseased vessel, and blood can normally flow into the inner tube through the near end donor hole without being hindered by the guide wire.

Preferably, another common connecting part is arranged between the inner tube and the outer tube and is positioned in front of the blood supply hole marking part, and a guide wire inserting hole is formed in the other common connecting part and is communicated into the inner tube from the outer tube.

The guide wire insertion hole can be used for guiding or withdrawing a guide wire quickly and conveniently.

Preferably, the side surface of the tip tube is provided with a distal blood supply hole.

The distal donor orifice may serve as an additional blood flow port to ensure blood flow continuity and adequate blood flow.

Preferably, the inner tube is provided with a support tube section, the support tube section is correspondingly filled in the hollow cavity section of the balloon, and the support tube section is used for resisting the pressure of the balloon and keeping the balloon not deformed.

After the balloon is expanded in a blood vessel, the balloon also applies larger extrusion force to the tube body in the hollow cavity of the balloon, and the supporting tube section is used for solving the problem, so that the inner tube section (namely, the supporting tube section is basically identical to the inner tube section) in the hollow cavity of the balloon maintains a normal shape and cannot be pressed to deform after the balloon is expanded, and the normal smoothness of a blood flow passage is ensured; in turn, the balloon can not be sunk into the hollow cavity, but can play a good expansion role on the blood vessel under the support of the support pipe section, and the drug coating can fully play a role in contact with the wall of the blood vessel.

Preferably, the supporting pipe section comprises an inner layer, a middle layer and an outer layer, the inner layer and the outer layer are polymer material layers, and the middle layer is a metal framework layer.

Preferably, the middle layer consists essentially of interlaced metal filaments.

Preferably, the metal wires have a braiding angle of β and 0 ° < β ≦ 90 °.

Preferably, the middle layer is a spiral metal wire.

Preferably, the diameter of the spiral metal wire is 0.01-1 mm.

Preferably, the pitch of the spiral wire is 0.01 to 1 mm.

Preferably, the support tube section is in the form of an axial multiple-turn bulge.

The shape of the axial multiturn bulge is the same as that of a caterpillar, the compression resistance is mainly improved, particularly, for a balloon with metal mesh restraint, the balloon is restrained by the metal mesh after being expanded, concave-convex areas appear on the balloon, and the shape of the multiturn bulge is also the same, the shape of the supporting tube section is set to be more compliant with the stress of the balloon, the fitting degree is better, the position is stable, the original shape is well kept, the balloon can not be sunken into the hollow cavity in turn, the supporting tube section plays a better expansion role on a blood vessel under the support of the supporting tube section, the balloon is more fully contacted with the blood vessel wall, and the drug coating can better exert the effect.

Preferably, the support tube section is provided with a balloon length mark part.

Preferably, the inner tube is an integrally formed single-layer or multi-layer medical catheter.

The inner tube is not provided with the supporting tube section, and the simple whole section is a single-layer or multi-layer medical catheter, so that the production and the processing are simpler.

Preferably, the drug balloon catheter further comprises a metal net, the metal net is wrapped outside the balloon, and two ends of the metal net are fixedly connected to the balloon.

The metal mesh is right the sacculus retrains the segmentation to eliminate in clinical common "dog bone" effect when independently using the sacculus expansion blood vessel, the cooperation the sacculus cuts the plaque of pathological change blood vessel department, support the pipeline section and can guarantee in reverse the expansion effect of sacculus reaches the cutting effect of metal mesh to the plaque, intervenes the in-process, along with the mediation of pathological change blood vessel, also have more and more blood to flow through between the sacculus surface of restraint and the vascular wall, the inside blood flow path of cooperation sacculus pipe, very big distal end ischemia situation of having alleviated, further extension intervention time, make with medicine, the cutting more abundant, promote treatment by a wide margin.

The invention has the following technical advantages:

1) after the balloon is expanded, the blood flow anti-blocking mechanism ensures that a stable and smooth blood flow passage is formed in the balloon catheter, the blood flow at two ends of the balloon is not blocked, the far-end ischemia is avoided, and the occurrence of complications is reduced;

2) the blood flow anti-blocking mechanism prolongs the interventional therapy time, stably supports the saccule from the inside, strengthens the top pasting effect of the saccule on the blood vessel wall, prolongs the drug delivery time, improves the contact area of a drug coating, and realizes lower drug loading and higher drug transfer rate compared with the traditional drug saccule;

3) the blood flow anti-blocking mechanism prolongs the interventional therapy time, stably supports the saccule from the inside, and strengthens the top sticking effect of the saccule on the blood vessel wall, namely, can strengthen the cutting effect of the metal mesh outside the saccule on the plaque;

4) the blood flow anti-blocking mechanism prolongs the interventional therapy time, so that the balloon can expand and shape the blood vessel at the pathological change position more durably and stably, and the blood vessel is not easy to retract after the balloon is withdrawn.

Drawings

FIG. 1 is a schematic diagram of the overall structure of an embodiment of the present invention;

FIG. 2 is a schematic diagram of the overall structure of an embodiment of the present invention;

FIG. 3 is a schematic structural view of the inner and outer tubes and the common connection portion in an embodiment of the present invention;

FIG. 4 is a schematic diagram of a proximal donor orifice and its inlet angle in an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a proximal donor site in a multi-column staggered arrangement according to an embodiment of the present invention;

FIG. 6 is a schematic structural view of a support tube segment according to an embodiment of the present invention;

FIG. 7 is a schematic structural view of a middle layer of a support tube section in an embodiment of the present invention, wherein a plurality of wires are interlaced;

FIG. 8 is a schematic structural view of the middle layer of the support tube section in the form of a single helical wire in accordance with an embodiment of the present invention;

FIG. 9 is a schematic structural view of a support tube segment in an axially multiple-turn inflated configuration in accordance with an embodiment of the present invention;

FIG. 10 is a schematic view of the inner and outer tubes of the present invention in the form of a double lumen tube;

the names of the parts corresponding to the numbers in the drawing are respectively 1-tip tube, 2-balloon, 3-balloon length marking part, 4-metal net, 5-donor hole marking part, 6-supporting tube section, 61-inner layer, 62-middle layer, 63-outer layer, 7-near-end donor hole, 8-inner tube, 9-outer tube, 10-guide wire inserting hole, 11-hypotube, 12-marking band, 13-catheter reinforcing part, 14-catheter seat, 15-guide wire, a-common connecting part, b-inflation cavity, α -liquid inlet angle of near-end donor hole 7 and β -weaving angle of metal wire.

Detailed Description

The invention will be further illustrated by means of specific embodiments in the following description with reference to the accompanying drawings:

referring to fig. 1 and 2, an embodiment of a drug balloon catheter capable of maintaining blood supply at a distal end comprises a tip tube 1, a balloon 2, a metal mesh 4, an inner tube 8, an outer tube 9, a hypotube 11, a catheter reinforcement 13 and a catheter seat 14, wherein the inner tube 8 is arranged in the outer tube 9, the proximal end of the balloon 2 is fixedly connected to the outer tube 9, the distal end of the balloon 2 is fixedly connected to the tip tube 1, the metal mesh 4 is wrapped outside the balloon 2, two ends of the metal mesh 4 are fixedly connected to the balloon 2, the inner tube 8 extends out of the outer tube 9 and penetrates through a hollow cavity of the balloon 2, the distal end of the inner tube 8 extends out of the balloon 2 and is communicated with the tip tube 1, the distal end of the hypotube 11 is fixedly connected to the proximal end of the outer tube 9, a marker band is arranged on the hypotube 11, and the distal end of the catheter reinforcement 13 is fixedly connected. The blood flow anti-blocking device is used for forming a blood flow passage which passes through the section of the balloon 2 and is communicated with the blood vessel in the medicine balloon catheter.

With reference to fig. 1, 2 and 3, the blood flow blockage preventing mechanism includes a plurality of proximal blood supply holes 7, a common connection portion a is provided between the inner tube 8 and the outer tube 9, the proximal blood supply holes 7 are provided on the common connection portion a, the proximal blood supply holes 7 are led into the inner tube 8 from the outer tube 9, a space between the inner tube 8 and the outer tube 9 where the common connection portion a does not exist is a pressurizing cavity b communicated with the inner cavity of the balloon 2, and the pressurizing cavity b is used for inflating and expanding the balloon 2. The common connection part a can adopt welding, gluing and other modes, in practical arrangement, the common connection part a can be an arc-shaped interlayer clamped between the inner pipe 8 and the outer pipe 9, the corresponding approximate angle range is preferably 45-270 degrees, and the indication is given in fig. 3, namely the opening of the proximal blood supply hole 7 can be conveniently and effectively ensured. In the actual manufacturing process, the inner tube 8 is in an eccentric, rather than concentric, position with respect to the outer tube 9, as shown in fig. 3, to meet the need for a common connection between the two. It is worth mentioning that the inner tube 8 and the outer tube 9 may be two separate tubes, or may be replaced by a double lumen tube as shown in fig. 10.

The liquid inlet angle of the near-end blood supply hole 7 is 0-180 degrees (not including 0 degree and 180 degrees), namely, the horizontal included angle of the central axis of the pore channel is α in fig. 4, the value of α is preferably 45 degrees, the pore channel of the near-end blood supply hole 7 inclines towards the balloon 2 from top to bottom, good blood flow guiding and resistance reducing effects can be achieved, and in order to further improve the effect, a hydrophilic coating can be coated on the inner surface of the near-end blood supply hole 7.

The proximal blood supply holes 7 are arranged in a plurality of staggered rows, such as two adjacent rows in a front-back insertion arrangement as shown in fig. 5. Although the strength of the tube is reduced due to the opening, the influence of the proximal blood supply holes 7 distributed in the manner can be reduced as much as possible, so that the tube body at the opening section is uniformly stressed, the tube body is prevented from being bent and broken in the using process, and the effect is better than that of another optional square array arrangement form (the illustration is omitted). A circular hole is conventionally selected as the proximal blood supply hole, the diameter range is 0.05-0.5 mm, and holes with various sizes can be mixed.

The section of the inner tube 8 located in front of the proximal feeding hole 7 is provided with a feeding hole mark 5. as can be seen in fig. 1 and 2, the feeding hole mark 5 can be used as a reference for the position of the proximal feeding hole 7 and cooperates with the guide wire 15 to ensure that the guide wire 15 has been withdrawn to a position where it does not obstruct the flow of blood through the proximal feeding hole 7. In addition, a further common connection portion a is also present between the inner tube 8 and the outer tube 9, which is located in front of the feeding hole marking 5, and a guide wire insertion hole 10 is provided in the further common connection portion a, and the guide wire insertion hole 10 leads from the outer tube 9 into the inner tube 8, where the further common connection portion a can likewise be realized by means of welding, gluing, etc.

The side of the tip tube 1 may be provided with one or more distal blood supply holes, not shown in the drawings, which serve as additional blood flow ports complementing the orifice of the tip tube 1 to ensure the smooth blood flow path and increase blood flow.

In some embodiments, the whole section of the inner tube 8 is an integrally formed single-layer or multi-layer medical catheter, a material with flexibility and compression resistance and bending resistance is selected, in the scheme, a PI tube is suitable for being used as the inner tube 8, the deformation resistance of the PI tube is excellent, the flexibility can meet requirements, smoothness of a blood flow passage can be effectively guaranteed, other materials can be selected to be a single-layer NYLON tube, also can be a three-layer PEBAX/LLDPE/HDPE or NYLON/LLDPE/HDPE tube, and also can be other same or similar existing medical tubes commonly used in the field.

In other embodiments, the inner tube 8 is not an integral tube made of the same material, but a tube is specially designed in the hollow cavity section of the balloon 2, and the rest is the single-layer or multi-layer medical catheter mentioned above. It can be seen from fig. 1, 2 that be equipped with a support tube section 6 on the inner tube 8, support tube section 6 has the resistance to compression concurrently, anti buckling and high compliance performance, can bear under the pressure that exceeds 25atm and indeformable, be used for protecting inner tube 8 not to receive the buckling deformation, ensure that the blood flow passageway can not blocked, simultaneously reverse from inside carry out powerful support to the sacculus, make sacculus 2 to the expansion of vascular wall, the top is pasted the effect better, also make the cutting effect of the outer metal mesh 4 of sacculus 2 to the plaque better simultaneously.

The supporting tube section 6 is correspondingly filled in the section of the hollow cavity of the balloon 2, the supporting tube section 6 belongs to a part of the inner tube 8, two ends of the supporting tube section 6 are fixedly connected with the rest part of the inner tube 8 (or the near end of the supporting tube section 6 is fixedly connected with the near end part of the inner tube 8, and the far end of the supporting tube section 6 is directly fixedly connected with the tip tube 1), the length of the supporting tube section 6 is basically equal to the length of the hollow cavity of the balloon 2, the end part of the rest part of the inner tube 8 (or the near end of the tip tube 1) is allowed to slightly extend into the hollow cavity of the balloon 2 and then is fixedly connected with the supporting tube section 6 into a whole during actual production, or the end part of the supporting tube section 6 is allowed to slightly extend out of the hollow cavity of the balloon 2 and is fixedly connected.

Further, as shown in fig. 6, the support tube section 6 includes an inner layer 61, a middle layer 62 and an outer layer 63, the inner layer 61 and the outer layer 63 are polymer material layers, such as PTFE, nylon, PEBAX, and the like, the middle layer 62 is a metal framework layer, such as 316L, 304, and the like, the metal framework layer has two suitable manufacturing forms, one is formed by metal wires which are woven in a staggered manner, as shown in fig. 7, the weaving angle of the metal wires is 0-90 degrees (not including 0 degree), β in the drawing, and the other is a spiral metal wire, as shown in fig. 8, the diameter variation range of the spiral metal wire is 0.01-1 mm, the pitch variation range of the spiral metal wire is 0.01-1 mm, and the support tube section 6 is provided with a balloon length mark portion 3 to visually provide reference information of the balloon length.

Still further, the supporting tube section 6 is in the shape of an axial multiple-turn bulge, like a caterpillar, as shown in fig. 9, and can be made into such a shape by processing only the outer layer 63, which can resist compression more effectively and has better compatibility with a balloon with a metal net. Because the sacculus that receives the metal mesh restraint also has the district's section of many circles of tympanites to exist, be the bulge between the circumference ring of metal mesh promptly, circumference ring limits the oppression to the sacculus and forms the boundary between the adjacent bulge, and support pipe section 6 with approximate shape just in time can assorted atress (protruding corresponds the arch, sunken cooperation form that corresponds sunken), makes the sacculus receive good support, has stable good expansion design effect to the vascular wall.

It will be appreciated by persons skilled in the art that the embodiments of the invention described above and shown in the drawings are given by way of example only and are not limiting of the invention. The objects of the present invention have been fully and effectively accomplished. The functional and structural principles of the present invention have been shown and described in the embodiments, and any variations or modifications may be made to the embodiments of the present invention without departing from the principles.

Claims

1. A drug balloon catheter capable of keeping blood supply at the far end comprises a tip tube (1), a balloon (2), an inner tube (8) and an outer tube (9), wherein the near end of the balloon (2) is fixedly connected to the outer tube (9) while the far end of the balloon is fixedly connected to the tip tube (1), the inner tube (8) extends out of the outer tube (9) and penetrates through the hollow cavity of the balloon (2), the far end of the inner tube (8) extends out of the balloon (2) and is communicated with the tip tube (1), and the drug balloon catheter is characterized in that: the blood flow anti-blocking device is used for forming a blood flow passage which passes through the section where the balloon (2) is located and is communicated with a blood vessel in the medicine balloon catheter.

2. A drug balloon catheter for maintaining blood supply to a distal end, according to claim 1, wherein: the blood flow anti-blocking mechanism comprises a plurality of near-end blood supply holes (7), a common connection part (a) is arranged between an inner tube (8) and an outer tube (9), the near-end blood supply holes (7) are formed in the common connection part (a), the near-end blood supply holes (7) are communicated into the inner tube (8) through the outer tube (9), and a space between the inner tube (8) and the outer tube (9) where the common connection part (a) does not exist is a pressurizing cavity (b) communicated with the inner cavity of the balloon (2).

3. A drug balloon catheter for maintaining blood supply to a distal end, as claimed in claim 2, wherein: the liquid inlet angle of the near-end blood supply hole (7) is 0-180 degrees.

4. A drug balloon catheter for maintaining blood supply to a distal end as claimed in claim 3, wherein: the liquid inlet angle of the near-end blood supply hole (7) is 45 degrees.

5. A drug balloon catheter for maintaining blood supply to a distal end, as claimed in claim 2, wherein: the proximal blood supply holes (7) are arranged in an array.

6. A drug balloon catheter for maintaining blood supply to a distal end, as claimed in claim 2, wherein: the near-end blood supply holes (7) are in a multi-row staggered arrangement.

7. A drug balloon catheter for maintaining blood supply to a distal end, as claimed in claim 2, wherein: the proximal blood supply hole (7) is a hole with a circular or polygonal section.

8. A drug balloon catheter for maintaining blood supply to a distal end, as claimed in claim 2, wherein: the section of the inner tube (8) which is positioned in front of the proximal blood supply hole (7) is provided with a blood supply hole mark part (5).

9. A drug balloon catheter for maintaining blood supply to a distal end as claimed in claim 8, wherein: and another common connecting part (b) positioned in front of the blood supply hole marking part (5) is also arranged between the inner tube (8) and the outer tube (9), a guide wire insertion hole (10) is formed in the other common connecting part (b), and the guide wire insertion hole (10) is communicated into the inner tube (8) from the outer tube (9).

10. A drug balloon catheter for maintaining blood supply to a distal end, as claimed in claim 2, wherein: the side surface of the tip tube (1) is provided with a plurality of distal blood supply holes.

11. A drug balloon catheter for maintaining blood supply to a distal end, as claimed in claim 2, wherein: the inner tube (8) is provided with a supporting tube section (6), the supporting tube section (6) is correspondingly filled in the hollow cavity section of the balloon (2), and the supporting tube section (6) is used for resisting the pressure of the balloon (2) in the hollow cavity and keeping the balloon not to deform.

12. A drug balloon catheter for maintaining blood supply to a distal end, as claimed in claim 11, wherein: the supporting pipe section (6) comprises an inner layer (61), a middle layer (62) and an outer layer (63), the inner layer (61) and the outer layer (63) are polymer material layers, and the middle layer (62) is a metal framework layer.

13. A drug balloon catheter for maintaining blood supply to a distal end, as claimed in claim 12, wherein: the middle layer (62) is mainly composed of interlaced metal wires.

14. A drug balloon catheter for maintaining blood supply to a distal end as claimed in claim 13, wherein: the weaving angle of the metal wire is 0-90 degrees.

15. A drug balloon catheter for maintaining blood supply to a distal end, as claimed in claim 12, wherein: the middle layer (62) is a spiral metal wire.

16. A drug balloon catheter for maintaining blood supply to a distal end as claimed in claim 15, wherein: the diameter of the spiral metal wire is 0.01-1 mm.

17. A drug balloon catheter for maintaining blood supply to a distal end as claimed in claim 15, wherein: the thread pitch of the spiral metal wire is 0.01-1 mm.

18. A drug balloon catheter for maintaining blood supply to a distal end, as claimed in claim 11, wherein: the support tube section (6) is formed in a shape of multiple-ring bulging in the axial direction.

19. A drug balloon catheter for maintaining blood supply to a distal end, as claimed in claim 11, wherein: the supporting pipe section (6) is provided with a balloon length marking part (3).

20. A drug balloon catheter for maintaining blood supply to a distal end, as claimed in claim 2, wherein: the inner tube (8) is a single-layer or multi-layer medical catheter which is integrally formed.

21. A drug balloon catheter capable of maintaining a blood supply at a distal end according to any one of claims 1 to 19, wherein: the medicine balloon catheter further comprises a metal net (4), the metal net (4) is wrapped outside the balloon (2), and two ends of the metal net (4) are fixedly connected to the balloon (2).