CN217138952U - Vasodilator and elongated inner tube for balloon catheter - Google Patents

Abstract

The utility model discloses a blood vessel expansion device and be used for long and thin inner tube of sacculus pipe, one of them blood vessel expansion device, include: an elongated outer tube surrounding a first lumen extending between a distal end and a proximal end thereof; an elongate inner tube surrounding a second lumen extending between a distal end and a proximal end thereof for receiving a guidewire therein; a portion of the elongated inner tube is received within the first lumen, a distal end of the elongated inner tube extending beyond a distal end of the elongated outer tube; the elongate inner tube comprising a tube wall having one or more channels defined therein extending between a distal end and a proximal end of the elongate inner tube for passage of blood flow therethrough; and an expandable balloon having two ends, one end secured to the distal end of the elongated outer tube and the other end secured to a portion of the elongated inner tube extending beyond the distal end of the elongated outer tube.

Description

Vasodilator and elongated inner tube for balloon catheter

Technical Field

The present disclosure relates to a vessel dilation device, and in particular, to a balloon catheter for dilating a vessel.

Background

Percutaneous interventional procedures using balloon catheters have been more commonly performed on patients for treating arterial stenosis caused by a lesion or other occlusion. Most of existing interventional balloon catheter products adopt a structural type of a single-cavity pipeline, and a balloon is guided to a narrow lesion area through a guide wire, so that operation treatment is facilitated.

However, in the interventional treatment of some complicated stenotic vessels, the expansion of the balloon can block the blood flow in the stenotic region of the vessel, resulting in intermittent short-term ischemia of the distal tissue and sudden rise of the blood pressure of the proximal organ.

Such blockages can increase the operational risk of the procedure, and even a blockage of too long duration can be life threatening to the patient. Therefore, during coronary intervention, the balloon dilatation time is mostly only 30 to 60 seconds. However, the limited expansion time may prevent complete release of the drug coating on the balloon surface or prevent complete release of the stent, resulting in poor stent adherence.

Accordingly, there is a need to devise a balloon catheter that addresses at least some of the above problems or provides the public with an alternative.

SUMMERY OF THE UTILITY MODEL

The utility model provides a blood vessel expansion device, especially a sacculus pipe, it can guarantee when the sacculus fully expands that the blood flow of narrow pathological change region is unobstructed, makes the sacculus can prolong at the operating time of vascular pathological change position from this to improve the operation success rate, reduce the operation risk.

The features and advantages of the present disclosure will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the principles disclosed herein. The features and advantages of the disclosure may be realized and obtained by means of the instruments and combinations particularly pointed out in the specification.

According to a first aspect of the present disclosure, there is provided a vasodilator device comprising: an elongated outer tube surrounding a first lumen extending between a distal end and a proximal end thereof; an elongate inner tube surrounding a second lumen extending between a distal end and a proximal end thereof for receiving a guidewire therein; a portion of the elongated inner tube is received within the first lumen, a distal end of the elongated inner tube extending beyond a distal end of the elongated outer tube; the elongate inner tube including a tube wall having one or more channels defined therein extending between distal and proximal ends of the elongate inner tube for passage of blood flow therethrough; and an expandable balloon having two ends, one end secured to the distal end of the elongated outer tube and the other end secured to a portion of the elongated inner tube extending beyond the distal end of the elongated outer tube.

The vasodilator device, wherein the outer elongate tube and the inner elongate tube may define therebetween a perfusion lumen in communication with the expandable balloon.

The vasodilator device, wherein the elongate inner tube may have a first opening at its proximal end in fluid isolation from the first lumen, the first opening may be provided at the junction of the elongate inner tube and the elongate outer tube.

The vasodilator device, wherein the junction of the inner elongate tube and the outer elongate tube may be spaced from the junction of the outer elongate tube and the expandable balloon.

The vasodilator device wherein the first opening may comprise an entrance to the second lumen and an entrance to the one or more channels.

The vasodilator device wherein the distal end of the elongate inner tube may comprise a second opening, the second opening may comprise an outlet of the one or more channels.

The vasodilator device may comprise 8 channels radially spaced about the longitudinal axis of the second lumen.

The vasodilator device may comprise 3 channels radially spaced about the longitudinal axis of the second lumen.

The vasodilator device may comprise at least one channel of generally half-moon shaped cross-section.

The vasodilator device may be one in which the channel of generally half-moon shaped cross-section extends around only a portion of the second lumen.

The vasodilator device may be wherein the longitudinal axes of the one or more channels and the second lumen may be aligned.

The inner tube of the vasodilator device has an outer diameter in the range of about 0.9 to 2.4mm and the second lumen of the inner tube has a diameter in the range of about 0.4 to 1.0 mm.

The total length of the inner tube of the blood vessel expansion device ranges from about 300 mm to about 600 mm.

The sum of the cross-sectional areas of the one or more passageways of the vasodilator device is about 0.1-3.7mm² 。

The one or more channels of the vasodilator device are configured to accommodate a blood flow of about 2.2 ml.

According to a second aspect of the present disclosure, there is provided a balloon catheter inner tube for guiding a guidewire therethrough in use of the balloon catheter, comprising: a tube wall having one or more channels defined therein extending between distal and proximal ends of the elongate inner tube, the channels sized for blood flow therethrough; and a lumen enclosed within the tube wall and extending along the inner tube, the lumen for receiving a guidewire therein.

One or more channels in the elongate inner tube are configured to accommodate a blood flow of about 2.2 ml.

According to a third aspect of the present disclosure, there is provided a balloon catheter manufacturing method, the method comprising: providing an elongate outer tube comprising a first lumen extending between a distal end and a proximal end thereof; providing an elongate inner tube comprising a tube wall and a second lumen surrounded by the tube wall, the tube wall having one or more channels defined therein, the channels extending between a proximal end and a distal end of the inner tube; inserting the elongated inner tube into the first lumen through an opening located near a distal end of the elongated outer tube until a proximal end of the elongated inner tube engages the elongated outer tube and a distal end of the elongated inner tube extends a predetermined length beyond the distal end of the elongated outer tube; securing the elongated inner tube with the elongated outer tube at a junction such that the second lumen and the one or more channels are fluidly isolated from the first lumen; a proximal end of a balloon is fixedly attached to a distal end of the outer tube, and a distal end of the balloon is fixedly attached to a distal end of the inner tube.

The method for manufacturing a balloon catheter may further include: a heparin coating and/or a hydrophilic coating is applied to the surface of the one or more channels.

The method for manufacturing a balloon catheter may further include: one or more mandrels are provided as support for the one or more channels when the inner and outer elongate tubes are secured at the junction.

Drawings

In order to describe the manner in which the above-recited and other advantages and features of the disclosure can be obtained, a more particular description of the principles briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only exemplary embodiments of the disclosure and are not therefore to be considered to be limiting of its scope, the principles herein are described and explained with additional specificity and detail through the use of the accompanying drawings. Preferred embodiments of the present disclosure will now be described in further detail, by way of example, with reference to the accompanying drawings, in which:

fig. 1A shows a schematic view of an exemplary balloon catheter.

Fig. 1B shows a schematic a-a cross-sectional view of the balloon catheter of fig. 1A.

Fig. 1C shows an enlarged schematic view of region B of the balloon catheter of fig. 1B.

Fig. 1D shows a schematic C-C cross-sectional view of the balloon catheter of fig. 1C.

Fig. 2A shows a schematic longitudinal cross-sectional view of an exemplary balloon catheter that includes a blood channel in addition to the balloon catheter of fig. 1A-D.

Fig. 2B shows an enlarged schematic view of region F of the balloon catheter in fig. 2A.

Fig. 2C shows an enlarged schematic view of region E of the balloon catheter of fig. 2A.

Fig. 2D shows an enlarged schematic view of the region G of the balloon catheter in fig. 2A.

Fig. 3A-C show schematic cross-sectional views of the exemplary balloon catheter along D-D in fig. 2A.

Fig. 4A shows a schematic inner tube of an exemplary balloon catheter.

Fig. 4B shows a schematic cross-sectional view of the inner tube H-H of the exemplary balloon catheter of fig. 4A.

Fig. 4C shows a schematic cross-sectional view of the inner tube I-I of the exemplary balloon catheter of fig. 4A.

Fig. 5A shows a schematic view of an inner tube of an exemplary balloon catheter.

Fig. 5B shows a schematic cross-sectional view of the inner tube J-J of the exemplary balloon catheter of fig. 5A.

Fig. 5C shows a schematic cross-sectional view of the inner tube K-K of the exemplary balloon catheter of fig. 5A.

Fig. 6A shows a schematic inner tube of an exemplary balloon catheter.

Fig. 6B shows a schematic cross-sectional view of the inner tube L-L of the exemplary balloon catheter of fig. 6A.

Fig. 6C shows a schematic cross-sectional view of the inner tube M-M of the exemplary balloon catheter of fig. 6A.

The drawings include: 10-balloon catheter, 12-connector, 14-port, 16-lumen, 20-elongate outer tube, 22-outer tube proximal end, 24-outer tube distal end, 25-perfusion lumen, 26-first lumen, 28-hypotube, 30-elongate inner tube, 32-inner tube proximal end, 34-inner tube distal end, 36-inner tube wall, 38-second lumen, 40-blood flow channel, 42-inner tube first opening, 43-guidewire inlet, 44-blood flow channel inlet, 46-inner tube second opening, 50-balloon, 52-balloon proximal end, 54-balloon distal end, 60-stenotic region, 70-catheter tip.

Detailed Description

Various embodiments of the present disclosure are discussed in detail below. While specific implementations are discussed, it should be understood that this is done for illustrative purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without parting from the spirit and scope of the disclosure.

In the following description, like reference numerals denote like components. "proximal" refers to the end of the catheter that is closer to the operator when the catheter is in use, and "distal" refers to the end of the catheter that is further from the operator when the catheter is in use. Numerals such as "first", "second", etc. in this specification are used only to indicate different components/parts and do not set any limit to the components/parts.

Fig. 1A illustrates anexemplary balloon catheter 10 including aconnector 12, an elongateouter tube 20, an elongateinner tube 30, and anexpandable balloon 50.

FIG. 1B is a schematic cross-sectional view A-A of FIG. 1A. Fig. 1C is an enlarged view of region B in fig. 1B.

As shown in fig. 1B and 1C, theconnector 12 has aport 14 connecting alumen 16 therein. Anouter tube 20 is attached to theconnector 12, and aproximal end 22 of theouter tube 20 interfaces with thelumen 16. A portion of theinner tube 30 is received inside theouter tube 20 and a portion extends beyond thedistal end 24 of theouter tube 20.Balloon 50 is secured at oneend 52 todistal end 24 ofouter tube 20 and at theother end 54 to the portion ofinner tube 30 extending beyonddistal end 24 ofouter tube 20 in a fluid tight securement.

Theouter tube 20 has afirst lumen 26 in communication with theport 14 of theconnector 12, thefirst lumen 26 being surrounded by theouter tube 20 and extending between the distal and proximal ends of theouter tube 20. At least a portion of theinner tube 30 near theproximal end 32 is received within thefirst lumen 26 of theouter tube 20, and thedistal end 34 of theinner tube 30 extends beyond thedistal end 24 of theouter tube 20. Thewall 36 of theinner tube 30 surrounds a second lumen 3B, whichsecond lumen 38 extends between the distal and proximal ends of theinner tube 30. A guidewire may be received into thesecond lumen 38 from an opening at theproximal end 32 of theinner tube 30 and extend along thesecond lumen 38 beyond an exit of thecatheter tip 70.

Theouter tube 20 and theinner tube 30 define therebetween aperfusion lumen 25, theperfusion lumen 25 being a fluid passage formed between the inner lumen wall of theouter tube 20 and the outer wall of theinner tube 30, which is in fluid communication with theballoon 50. This arrangement placesballoon 50 in fluid communication withport 14 ofconnector 12, wherebyballoon 50 may be inflated to dilatestenotic lesion 60 by infusing fluid fromport 14 ofconnector 12 throughfirst lumen 26 andinfusion lumen 25 to balloon 50.

1A-D, further included is ahypotube 28 located within thelumen 26 of the outer tube and extending from theproximal end 22 of theouter tube 20 to near theproximal end 22 of the inner tube, which serves to reinforce the strength of the length of the catheter, making it easier to advance the balloon catheter within the blood vessel to the target site.

As shown in fig. 1A-D, when a stenotic lesion is dilated by a balloon during an interventional procedure, the inflated balloon may block blood flow, thereby possibly affecting the length of time that the procedure may be performed or causing a surgical risk.

In order to solve the above problems, the prior art proposes conceptual designs of providing a cannula outside the balloon or providing a blood flow channel inside the balloon, but these designs add extra structure, so that the volume of the catheter is increased, which may reduce the performance of the catheter passing through the lesion on the one hand, and may also reduce the stability of the balloon, so that the catheter is easy to break or cannot fully expand the lesion during the inflation process.

The utility model provides a blood vessel dilator especially relates to a sacculus pipe, and it can guarantee when the sacculus fully expands that the blood flow in narrow pathological change region is unobstructed, makes the working time of sacculus in the position of vascular pathological change can prolong from this to improve the operation success rate, reduce the operation risk.

Fig. 2A shows a schematic longitudinal cross-sectional view of an exemplary balloon catheter that further includes a blood channel in addition to the balloon catheter shown in fig. 1A-D. Fig. 2B shows an enlarged schematic view of the region labeled "F" in fig. 2A. Fig. 2C shows an enlarged schematic view of the area labeled "E" in fig. 2A. Fig. 2D shows an enlarged schematic view of the region labeled "G" in fig. 2A.

As shown in fig. 2A-D, the elongateinner tube 30 of the balloon catheter includes atube wall 36 and asecond lumen 38 surrounded thereby. Unlike the balloon catheter shown in fig. 1A-D, in the embodiment shown in fig. 2A-D, thewall 36 of theinner tube 30 has one ormore channels 40 defined therein, thechannels 40 extending longitudinally between the proximal end of theinner tube 30 to the distal end of theinner tube 30 for the passage of blood flow during surgery.

As shown in fig. 2A and 2B, the elongateinner tube 30 extends within thelumen 26 of the elongateouter tube 20, with its proximal end engaging theouter tube 20 near the distal end of theouter tube 20. Theinner tube 30 has afirst opening 42 at the junction facing outward of theouter tube lumen 26, thefirst opening 42 including aguide wire inlet 43 and a bloodflow channel inlet 44. Thefirst opening 42 is fluidly isolated from thelumen 26 of theouter tube 40 so that blood does not contact or mix with the fluid in thelumen 26 when entering thechannel 40 via the bloodflow channel inlet 44.

As shown in fig. 2C and 2D, thepassage 40 extends within thewall 36 of theinner tube 30 and terminates at asecond opening 46 at thedistal end 34 of theinner tube 30, i.e., thesecond opening 46 comprises an outlet of one or more passages.

In the embodiment shown in fig. 2A, theblood flow passageway 40 of theinner tube 30 terminates near the junction of theinner tube 30 and the distal end of the balloon, and the guidewire lumen of theinner tube 30 extends beyond the distal end of theballoon 50, the distal segment of the inner tube extending beyond not including the blood flow passageway. The distal section of the extended inner tube may be further connected to acatheter tip 70 made of a material having a softer hardness than the catheter tip, so that the overall hardness of the balloon catheter is gradually softened, and the diameter of the distal section is gradually reduced, thereby facilitating entry into and protection of stenotic lesions.

The balloon catheter shown in fig. 2A-D, because of the additional blood passageways provided in the inner wall, allows blood to flow through these passageways during the interventional procedure, and does not interrupt blood flow when the balloon is inflated. Therefore, compared with a balloon catheter without a blood flow channel, the time of interventional operation can be prolonged, and the balloon has more sufficient time to expand the blood vessel or release carried medicines.

Compared with a blood flow channel arranged on a balloon or an additional sleeve, the blood flow channel in the present disclosure is arranged on the wall of an inner tube and is independent of the balloon, the shape and the function of the channel are predictable, and the channel can be easily changed according to the actual needs of different blood vessels in the manufacturing process without affecting the stability of the balloon. This design does not require additional components in the catheter, thereby providing a very compact catheter design.

In an exemplary embodiment, the inner tube and outer tube are joined at a distance from the outer tube and balloon, but to minimize the length of the blood passageway, the preferred location of the join should be as close to the proximal end of the balloon as possible.

Fig. 3A-C illustrate three exemplary blood flow channel arrangements, respectively, corresponding to the cross-section of the balloon catheter of fig. 2A along line D-D, where the line D-D is located at the junction of the distal end of the balloon and the inner tube.

In the exemplary embodiment of fig. 3A-C, the outer layer of the cross-section is aballoon 50 and the inner layer is aninner tube 30. Wherein theinner tube 30 includes atube wall 36 surrounding alumen 38, thelumen 38 for guiding a guidewire path for a guidewire, thetube wall 36 having one or moreblood flow channels 40 therein.

The embodiment shown in figure 3A includes 8blood flow channels 40 radially spaced in thevessel wall 36, each having a generally circular cross-section. Fig. 4A-C show schematic views of an inner tube corresponding to the exemplary balloon catheter of fig. 3A.

3B includes 3blood flow channels 40 radially spaced apart in thevessel wall 36, each having a generally arcuate cross-section. Fig. 5A-C show schematic views of an inner tube corresponding to the exemplary balloon catheter of fig. 3B.

In fig. 3A-B, thelumen 38 is longitudinally coaxial with thevessel wall 36, and theblood flow passages 40 are evenly distributed about thelumen 38 and are longitudinally parallel or aligned with each other. In other embodiments, the blood flow channels may be distributed in other ways within the lumen as desired.

Fig. 3C shows an embodiment comprising a single blood flow channel provided in thevessel wall 36. Thelumen 38 is eccentrically disposed within theinner tube 30, and theblood flow passageway 40 is generally crescent-shaped in cross-section and surrounds only a portion of thelumen 38. Fig. 6A-C show schematic views of an inner tube corresponding to the exemplary balloon catheter of fig. 3C.

Fig. 4A-6C illustrate various exemplary embodiments of an elongateinner tube 30 for a balloon catheter for guiding a guidewire during an interventional procedure using the balloon catheter. Theinner tube 30 includes atube wall 36 having one ormore channels 40 defined therein, the one ormore channels 40 extending between the distal and proximal ends of the elongateinner tube 30 for passage of blood flow therethrough, and alumen 38; thelumen 38 is enclosed within thevessel wall 36 and extends through theinner tube 30, thelumen 38 for receiving a guidewire therein.

Inner tube 30, shown in fig. 4A-4C, has 8 blood flow channels uniformly distributed in the radial direction in its inner wall. Theinner tube 30 shown in fig. 5A-5C has 3 blood flow channels uniformly distributed in the radial direction in its inner wall.Inner tube 30, as shown in fig. 6A-6C, includes 1 blood flow channel in its inner wall. Optionally, in an exemplary embodiment, the blood flow passages are aligned with the longitudinal axis of the inner tube lumen, e.g., the longitudinal axis of each blood flow passage is parallel to the longitudinal axis of the inner tube lumen.

It will be readily appreciated that a flow channel of greater cross-sectional area allows more blood flow therethrough, and a flow channel of lesser cross-sectional area allows less blood flow therethrough. For an inner tube comprising a plurality of blood flow channels, the blood flow it allows through is related to the sum of the cross-sectional areas of all channels.

In one embodiment, the outer diameter (outside diameter) of the inner tube is in the range of about 0.9-2.4mm and the diameter of the lumen of the inner tube is in the range of about 0.4-1.0 mm.

In one embodiment, the sum of the cross-sectional areas of the one or more channels is about 0.1-3.7mm² The cross-section of the channel is for example the cross-section at the inlet/outlet of the channel.

In one embodiment, the total length of the inner tube ranges from about 300 mm to about 600 mm.

In one embodiment, one or more channels are configured to accommodate approximately 2.2ml of blood flow.

In exemplary embodiments, the elongated inner tube may be provided with a number of passages, a distribution pattern, and a cross-sectional shape as desired.

In exemplary embodiments, the diameter dimensions of the inner tube lumen and the blood flow channel may be kept constant or gradually decreasing in the longitudinal direction from the proximal end to the distal end, thereby satisfying different structural performance requirements.

In an exemplary embodiment, the material of the inner and outer tubes may be the same material or a combination of different materials to achieve different flexibility requirements, for example the material may be PEBAX 7233 or PEBAX 7233-PEBAX 7033.

The inner tube of the present disclosure may be an essential component in the construction of interventional balloon catheter products. The balloon catheter combined with the inner tube can be inserted into a blood vessel percutaneously and used in the process of passing through a local stenosis when performing percutaneous coronary intervention (PTCA) and percutaneous intravascular angioplasty (PTA), and can be used as a consumable in one of a plurality of instruments for the adjuvant therapy of coronary vessels and peripheral arterial vessels.

According to one embodiment of the present disclosure, a method of manufacturing a balloon catheter is provided, including providing an elongated outer tube including a first lumen extending between a distal end and a proximal end thereof, the first lumen including a lateral opening located near the distal end of the elongated outer tube; providing an elongate inner tube comprising a tube wall having one or more channels defined therein and a second lumen surrounded by the tube wall; inserting the elongated inner tube into the first lumen through an opening in a side of the elongated outer tube until a proximal end of the elongated inner tube engages the elongated outer tube and a distal end of the elongated inner tube extends a predetermined length beyond a distal end of the elongated outer tube; securing the elongated inner tube with the elongated outer tube at a junction such that the second lumen and the one or more channels are fluidly isolated from the first lumen; a proximal end of a balloon is fixedly attached to a distal end of the outer tube, and a distal end of the balloon is fixedly attached to a distal end of the inner tube.

In an exemplary embodiment, the inner tube may be assembled with the balloon and outer tube by laser welding or/and hot air welding, ultimately forming a balloon catheter. When the inner pipe of the multi-cavity pipeline is welded with the balloon and the outer pipe, smoothness of the multi-cavity pipeline is guaranteed, and welding connection stability is guaranteed. For the connection of the far end of the pipe body, the multi-cavity pipeline is subjected to proper shearing and trimming operation and then welded; for welding at the multi-lumen structure, one or more suitable mandrels may be used simultaneously as supports to achieve a stable uniform lumen structure.

In order to better maintain the functional function of the balloon catheter, the surface of the blood flow channel can be coated with heparin coating and/or hydrophilic coating, so that the possibility of platelet adhesion and thrombus formation on the surface of the catheter is reduced, better anticoagulation performance and hydrophilicity are obtained, and the service performance of the balloon catheter product is safer and more reliable.

The above embodiments are described herein by way of example only. It is understood that the shapes of the inner tube, the outer tube and the balloon, the number, distribution and cross-sectional shape of the blood flow passages in the above embodiments are only examples, and those skilled in the art can make different arrangements from the above embodiments according to actual needs.

Many variations are possible without departing from the scope of the disclosure as defined in the claims. While various examples and other information are used to explain various aspects within the scope of the appended claims, the particular features or arrangements of such examples should not be taken as limiting the claims, as those skilled in the art will be able to use the claimed examples to derive various implementations.

Furthermore, although some subject matter may have been described in language specific to structural features and/or methodological steps, it is to be understood that the subject matter defined in the claims is not necessarily limited to the described features or acts. For example, such functionality may be distributed differently or performed in components other than those identified herein. The described features and steps are disclosed as examples only of components of systems and methods within the scope of the appended claims.

Claims (17)

1. A vasodilator device, comprising:

an elongated outer tube surrounding a first lumen extending between a distal end and a proximal end thereof;

an elongate inner tube surrounding a second lumen extending between a distal end and a proximal end thereof for receiving a guidewire therein; a portion of the elongated inner tube is received within the first lumen, a distal end of the elongated inner tube extending beyond a distal end of the elongated outer tube; the elongated inner tube including a tube wall having a plurality of channels defined therein extending between distal and proximal ends of the elongated inner tube for passage of blood flow therethrough; and

an expandable balloon having two ends, one end secured to the distal end of the elongate outer tube and the other end secured to a portion of the elongate inner tube extending beyond the distal end of the elongate outer tube.

2. The vasodilation device of claim 1, wherein the outer elongate tube and the inner elongate tube define an infusion lumen therebetween in communication with the expandable balloon.

3. The vasodilation device of claim 1, wherein the elongate inner tube has a first opening at its proximal end in fluid isolation from the first lumen, the first opening being disposed at the junction of the elongate inner tube and the elongate outer tube.

4. The vasodilation device of claim 3, wherein the junction of the inner elongate tube and the outer elongate tube is spaced apart from the junction of the outer elongate tube and the expandable balloon.

5. The vasodilation device of claim 3, wherein the first opening comprises an entrance to the second lumen and an entrance to the plurality of channels.

6. The vasodilation device of claim 1, wherein the distal end of the inner elongate tube comprises a second opening comprising an outlet of the plurality of channels.

7. The vasodilation device of claim 1, comprising 8 channels radially spaced about the longitudinal axis of the second lumen.

8. The vasodilation device of claim 1, comprising 3 channels radially spaced about the longitudinal axis of the second lumen.

9. The vasodilator device of claim 1, comprising at least one channel having a generally crescent-shaped cross section.

10. The vasodilator device of claim 9, wherein the channel that is generally crescent shaped in cross section extends around only a portion of the second lumen.

11. The vasodilation device of claim 1, wherein the plurality of channels are aligned with a longitudinal axis of the second lumen.

12. The vasodilator device of claim 1, wherein the inner tube has an outer diameter in the range of 0.9 to 2.4mm and the second lumen of the inner tube has a diameter in the range of 0.4 to 1.0 mm.

13. The vasodilator device of claim 1, wherein the inner tube has an overall length in the range of 300 and 600 mm.

14. The vasodilator device of claim 1, wherein the sum of the cross-sectional areas of the plurality of channels is between 0.1 mm and 3.7mm² 。

15. The vasodilator device of claim 1, wherein the plurality of channels are configured to accommodate about 2.2ml of blood flow.

16. An elongate inner tube for a balloon catheter for guiding a guidewire therethrough in use of the balloon catheter, comprising:

a tube wall having a plurality of channels defined therein extending between a distal end and a proximal end of the elongate inner tube, the channels sized for blood flow therethrough; and

a lumen enclosed within the tube wall and extending along the inner tube, the lumen for receiving a guidewire therein.

17. The elongate inner tube of claim 16, wherein the plurality of channels are configured to contain about 2.2ml of blood flow.

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