Microcatheter for chronic total occlusion of an artery

Abstract

The utility model provides a kind of microcatheter for chronic complete occlusion of artery, including catheter body, guide wire cavity is provided in catheter body, the rear end of catheter body is provided with operating handle, guide wire is arranged in guide wire cavity;Catheter body includes inner tube and outer tube;Outer tube is sleeved in outer tube, and first balloon and second balloon are provided on inner tube, and second balloon is sleeved with stent;First injection cavity and second injection cavity are arranged in inner tube, first injection cavity is communicated with first balloon, and second injection cavity is communicated with second balloon;The front end of outer tube is in abutment with first balloon, and outer tube is spaced apart from operating handle;Second balloon and stent are located between outer tube and inner tube.This microcatheter in the utility model, its inner tube is equipped with stent, without withdrawing microcatheter, puncture, expansion and stent implantation can be completed in one step, solve the technical problems of the prior art, such as the complexity of microcatheter withdrawal step, the difficulty of guide wire movement and stent insertion when microcatheter is withdrawn.

Description

Technical Field

[0001] This utility model relates to the field of human necessities, especially to the field of medical auxiliary equipment, and in particular to a microcatheter for chronic total occlusion of arteries. Background Technology

[0002] Chronic total occlusion (CTO) lesions refer to arterial lesions with an occlusion period of 3 months or more, commonly found in arteries and peripheral arteries. These lesions account for 15% to 25% of patients diagnosed by angiography. Due to partial tissue calcification at the site of CTO lesions, opening them is extremely difficult, and they have long been considered a major challenge in PCI (percutaneous coronary intervention) techniques, even being hailed as the "last bastion" of this field.

[0003] Most CTOs cannot be directly penetrated through the obstruction area by a guidewire, thus requiring the use of a microcatheter for penetration. A rigid guidewire (such as Conquest Pro) is inserted into the microcatheter, using "leverage" to increase the penetration force. Combined with techniques such as rotation or using a guidewire with a special tip, the obstruction area can be penetrated. After penetration, a stent can be implanted at the penetration site to restore arterial patency.

[0004] The general procedure for CTO stent implantation in the prior art is as follows: First, push the microcatheter to the proximal end of the obstruction area, assist the rigid guidewire to penetrate the obstruction area, after confirming the guidewire penetration, fix the guidewire, slowly withdraw the microcatheter to avoid guidewire displacement, and finally deliver the stent to the target position along the guidewire through the stent delivery system, and release the stent by balloon dilation to complete the stent implantation.

[0005] However, existing technologies have the following drawbacks: After the guidewire is penetrated through the obstruction area by the microcatheter, the guidewire needs to be fixed, the microcatheter is slowly withdrawn, and then the stent is sent into the target position along the guidewire. During the operation, the microcatheter and stent alternately enter and exit the blood vessel, which is complicated and can easily increase the risk of vascular injury during entry and exit, thus increasing the surgical risk.

[0006] When withdrawing a microcatheter, the guidewire needs to be fixed in place. If the guidewire moves away from the obstruction area, the puncture must be repeated. However, the guidewire is thin, and the movement of the microcatheter can easily cause the guidewire to move as well, resulting in a very low tolerance for error in the microcatheter withdrawal operation, increased uncertainty, and making the operation very difficult.

[0007] When a stent is delivered within a blood vessel, it comes into direct contact with the vessel wall. Compared to microcatheters or guidewires with a lubricating coating, stents experience greater resistance during delivery, making them more prone to blockages or failure to reach the target location on the first attempt, thus increasing the risk of perforation. Utility Model Content

[0008] The purpose of this invention is to provide a microcatheter for chronic total occlusion of an artery. This microcatheter for chronic total occlusion of an artery has a built-in stent on its inner tube, which allows for puncture, dilation and stent implantation to be completed in one step without the need to remove the microcatheter. This solves the technical problems of cumbersome microcatheter removal steps, easy movement of guidewire during microcatheter removal and difficulty in stent insertion in the prior art.

[0009] A microcatheter for chronic total arterial occlusion includes a catheter body comprising an inner tube and an outer tube, the outer tube being sleeved over the inner tube and slidably connected to the inner tube; a guidewire lumen is provided within the inner tube, and a guidewire is inserted within the guidewire lumen; a first balloon and a second balloon are disposed on the outer wall of the inner tube, the first balloon being located at the front end of the inner tube and the second balloon being located behind the first balloon; a first injection chamber and a second injection chamber are provided within the inner tube, the front end of the first injection chamber communicating with the interior of the first balloon, and the second injection chamber... The front end is connected to the interior of the second balloon; the rear end of the catheter body is provided with an operating handle, the operating handle is provided with a first injection port, a second injection port and a guidewire delivery port, the rear end of the first injection cavity is connected to the first injection port, the rear end of the second injection cavity is connected to the second injection port, and the rear end of the guidewire cavity is connected to the guidewire delivery port; a support is sleeved on the outside of the second balloon; the outer tube is located behind the first balloon, and the rear end of the outer tube is spaced from the front end of the operating handle; the second balloon and the support are located between the outer tube and the inner tube.

[0010] Furthermore, the inner tube is embedded with contrast agent at the second balloon position and / or the anterior end position.

[0011] Furthermore, a pull tab is fixedly provided at the rear end of the outer wall of the outer tube.

[0012] Furthermore, a limiting sleeve is fitted onto the inner tube, and the limiting sleeve has a through opening on its wall, which is located between the outer tube and the operating handle.

[0013] Furthermore, the first balloon is a compliant balloon or a semi-compliant balloon, and the second balloon is a non-compliant balloon.

[0014] Furthermore, the front end of the inner tube is tapered.

[0015] The above-mentioned method of using microcatheters for chronic total occlusion of arteries includes the following steps: Step 1: Insert the catheter body into the blood vessel, bringing the tip of the catheter body close to the obstruction area within the blood vessel.

[0016] Step 2: Push the tip of the guidewire out of the inner tube and penetrate the obstruction area.

[0017] Step 3: Advance the catheter body along the path through which the guidewire penetrates, so that the catheter body penetrates the obstruction area.

[0018] Step 4: Move the catheter body forward so that the second balloon is located in the obstruction area.

[0019] Step 5: The first balloon inflates, and the outer side of the first balloon abuts against the inner wall of the blood vessel, so that the inner tube is relatively fixed to the blood vessel.

[0020] Step 6: Retract the outer tube backward while keeping the inner tube in the same position, thereby exposing the stent and the second balloon.

[0021] Step 7: Inflate the second balloon to allow the stent to expand as the second balloon expands, thereby dilating the blood vessels in the obstructed area.

[0022] Step 8: The first balloon contracts, and the second balloon contracts.

[0023] Step 9: Remove the catheter body.

[0024] Furthermore, the following steps are included between step 3 and step 4: Step 301: Move the catheter body forward so that the first balloon is located in the obstruction area. The first balloon inflates to pre-dilate the blood vessels in the obstruction area. After dilation, the first balloon contracts.

[0025] Step 302: When obvious calcification of the artery wall is seen under fluoroscopy, step 301 can be repeated multiple times until the expected pre-dilation effect is achieved.

[0026] Furthermore, the method for inflating the first balloon is specifically as follows: A contrast agent is injected into the first injection port using an injection pump. The contrast agent enters the first balloon through the first injection cavity, causing the first balloon to inflate.

[0027] Furthermore, the specific method for inflating the second balloon is as follows: A contrast agent is injected into the second injection port using an injection pump. The contrast agent enters the second balloon through the second injection cavity, causing the second balloon to inflate.

[0028] Compared with existing technologies, the advantages of this invention are positive and obvious: The microcatheter of this invention has a built-in stent. Compared with the traditional CTO microcatheter, this invention completes all steps such as puncture, dilation and stent implantation in one go, which is highly efficient and simple to operate.

[0029] This invention allows the microcatheter to be deployed via a second balloon after the guidewire penetrates the obstruction area without being withdrawn from the blood vessel, greatly reducing the surgical risks such as perforation caused by repeated entry and exit of the microcatheter.

[0030] The stent of this invention is located in the interlayer between the outer tube and the inner tube. When the stent enters the blood vessel, it is wrapped and protected by the outer tube. The surface of the outer tube is smooth and has a hydrophilic lubricating coating, which provides better forward movement and reduces the risk of stent blockage and blood vessel perforation. Attached Figure Description

[0031] Figure 1 A schematic diagram of the structure of Embodiment 1 of this utility model.

[0032] Figure 2 A schematic diagram of the structure of the catheter body front end corresponding to step 2 in Embodiment 1 of this utility model.

[0033] Figure 3 A schematic diagram of the structure of the catheter body front end corresponding to step 5 in Embodiment 1 of this utility model.

[0034] Figure 4 A schematic diagram of the structure of the catheter body front end corresponding to step 6 in Embodiment 1 of this utility model.

[0035] Figure 5 A schematic diagram of the vertical cross-section structure of Embodiment 1 of this utility model.

[0036] Figure 6 A cross-sectional structural diagram of Embodiment 1 of this utility model.

[0037] Figure 7 A schematic diagram of step 1 in Embodiment 1 of this utility model.

[0038] Figure 8 A schematic diagram of step 2 in Embodiment 1 of this utility model.

[0039] Figure 9 A schematic diagram of step 3 in Embodiment 1 of this utility model.

[0040] Figure 10 A schematic diagram of step 4 in Embodiment 1 of this utility model.

[0041] Figure 11 A schematic diagram of step 5 in Embodiment 1 of this utility model.

[0042] Figure 12 A schematic diagram of step 6 in Embodiment 1 of this utility model.

[0043] Figure 13 A schematic diagram of step 7 in Embodiment 1 of this utility model.

[0044] Figure 14 A schematic diagram of the front end of the catheter body in Embodiment 3 of this utility model.

[0045] In the diagram: 1. Catheter body; 101. Guidewire lumen; 102. First injection chamber; 103. Second injection chamber; 2. Outer tube; 3. Inner tube; 4. Guidewire; 5. First balloon; 6. Second balloon; 7. Stent; 8. Operating handle; 801. First injection port; 802. Second injection port; 803. Guidewire delivery port; 9. Pulling strip; 10. Limiting cannula; 11. Vessel wall; 12. Obstruction area. Detailed Implementation

[0046] The following embodiments will further illustrate the present invention, but are not intended to limit the present invention. Example

[0047] like Figures 1 to 6 As shown, this embodiment provides a microcatheter for chronic total occlusion of an artery, including a catheter body 1.

[0048] The catheter body 1 includes an inner tube 3 and an outer tube 2. The outer tube 2 is sleeved outside the inner tube 3 and is slidably connected to the inner tube 3. The outer wall of the outer tube 2 is smooth and has a hydrophilic lubricating coating, giving it good lubricity and passability. A guidewire cavity 101 is provided inside the inner tube 3, and a guidewire 4 is inserted into the guidewire cavity 101.

[0049] A first balloon 5 and a second balloon 6 are disposed on the outer wall of the inner tube 3. The first balloon 5 is a compliant balloon, and the second balloon 6 is a non-compliant balloon. The first balloon 5 is used to fix the inner tube 3 in place by contacting the blood vessel, and the second balloon 6 is used to dilate the obstruction area 12 and deploy the stent 7. The stent 7 is sleeved on the outer side of the second balloon 6, and the model and size of the stent 7 can be changed according to the requirements.

[0050] The first balloon 5 is located at the front end of the inner tube 3, and the second balloon 6 is located behind the first balloon 5. The inner tube 3 is provided with a first injection chamber 102 and a second injection chamber 103 along its extension direction. The front end of the first injection chamber 102 is connected to the interior of the first balloon 5, and the front end of the second injection chamber 103 is connected to the interior of the second balloon 6.

[0051] An operating handle 8 is provided at the rear end of the catheter body 1. The operating handle 8 is provided with a first injection port 801, a second injection port 802 and a guidewire delivery port 803. The first injection port 801, the second injection port 802 and the guidewire delivery port 803 are isolated from each other. The rear end of the first injection cavity 102 is connected to the first injection port 801, the rear end of the second injection cavity 103 is connected to the second injection port 802, and the rear end of the guidewire cavity 101 is connected to the guidewire delivery port 803.

[0052] The front end of the outer tube 2 abuts against the rear end of the first balloon 5, and there is a certain distance between the rear end of the outer tube 2 and the front end of the operating handle 8. The distance is to provide space for the retraction of the outer tube 2. The second balloon 6 and the stent 7 are located between the outer tube 2 and the inner tube 3, so that the outer tube 2 covers the second balloon 6 and the stent 7.

[0053] A pull tab 9 is fixedly installed at the rear end of the outer wall of the outer tube 2, which can be used as a force point to retract the outer tube 2 backward. A limiting sleeve 10 is fitted on the inner tube 3. The limiting sleeve 10 is located between the outer tube 2 and the operating handle 8. The limiting sleeve 10 is used to limit the distance between the rear end of the outer tube 2 and the operating handle 8, so as to prevent the outer tube 2 from sliding backward during the insertion of the catheter body 1 into the blood vessel. A through opening is opened on the wall of the limiting sleeve 10, and the limiting sleeve 10 can be peeled off from the inner tube 3 through the opening, thereby releasing the space for the outer tube 2 to move backward along the inner tube 3, so as to facilitate the retraction of the outer tube 2.

[0054] The inner tube 3 has a contrast agent embedded at the position of the second balloon 6 and the front end of the inner tube 3 as a contrast point, so that the position of the front end of the inner tube 3 and the position of the second balloon 6 (i.e., the stent 7) can be more easily observed under fluoroscopy, which facilitates more accurate penetration of the obstruction area 12 and placement of the stent 7 in the obstruction area 12.

[0055] The usage steps of this embodiment are as follows: Step 1: As Figure 7 As shown, the catheter body 1 is ensured to be in its initial state, with the first balloon 5, the second balloon 6, and the stent 7 all in a contracted state. The outer tube 2 is wrapped around the stent 7 and the second balloon 6. This not only protects the stent 7 and the second balloon 6 but also improves the passage performance of the catheter body 1 within the blood vessel. The catheter body 1 in its initial state is then inserted into the blood vessel, bringing the tip of the catheter body 1 close to the obstruction area 12 within the blood vessel.

[0056] Step 2: As Figure 8 As shown, the tip of the guidewire 4 extends out of the inner tube 3 and penetrates the obstruction area 12.

[0057] Step 3: As Figure 9 As shown, the catheter body 1 advances along the path through which the guidewire 4 penetrates, and the catheter body 1 also penetrates the obstruction area 12.

[0058] Step 4: Move the catheter body 1 forward so that the second balloon 6 is located in the obstruction area 12.

[0059] Step 5: As Figure 10 As shown, a contrast agent is injected into the first injection port 801 using an injection pump. The contrast agent enters the first balloon 5 through the first injection cavity 102, causing the first balloon 5 to inflate. After the first balloon 5 inflates, the outer side of the first balloon 5 abuts against the inner wall of the blood vessel, thus fixing the inner tube 3 relative to the blood vessel.

[0060] Step 6: As Figure 11 As shown, the outer tube 2 is retracted backward, but the position of the inner tube 3 remains unchanged, thereby exposing the stent 7 and the second balloon 6.

[0061] Step 7: As Figure 12 As shown, a contrast agent is injected into the second injection port 802 using an injection pump. The contrast agent enters the second balloon 6 through the second injection cavity 103, causing the second balloon 6 to inflate. After the second balloon 6 inflates, the stent 7 expands along with the second balloon 6, thereby expanding the obstruction area 12.

[0062] Step 8: As Figure 13 As shown, the contrast agent in the first balloon 5 is extracted sequentially through the first injection port 801, and the contrast agent in the second balloon 6 is extracted through the second injection port 802. The first balloon 5 contracts, and the second balloon 6 contracts.

[0063] Step 9: Retract catheter body 1 backward to remove it from the body, thus completing the procedure. Example

[0064] This embodiment is a preferred embodiment of embodiment one. The first balloon 5 is a semi-compliant balloon. After the semi-compliant balloon is inflated beyond the nominal pressure, the balloon diameter can be precisely adjusted by controlling the pressure. Thus, it can both be attached to the blood vessel and continuously increase pressure to pre-expand the vascular obstruction area 12, achieving a multi-purpose effect.

[0065] In the usage method of Embodiment 1, the following step is added between step 3 and step 4 to achieve the application of pre-dilation of the first balloon 5: Step 301: Move the catheter body 1 forward so that the first balloon 5 is located at the obstruction area 12. Use an injection pump to inject contrast agent into the first injection port 801. The contrast agent enters the first balloon 5 through the first injection cavity 102, causing the first balloon 5 to inflate. After the first balloon 5 inflates, the obstruction area 12 is pre-dilated. After dilation, the first balloon 5 contracts.

[0066] Step 302: If significant calcification is observed in the vessel wall of artery 11 under fluoroscopy, step 301 can be repeated multiple times until the desired pre-dilation effect is achieved. If the lesion indentation cannot disappear even when the dilation pressure of the semi-compliant first balloon 5 is increased to 16 atm or exceeds the balloon burst pressure, a cutting balloon or plaque rotational atherectomy should be considered. Balloon pressure should not be increased further to avoid serious complications such as vessel rupture and perforation. Example

[0067] like Figure 14 As shown, this embodiment is a preferred embodiment of embodiment one. The front end of the inner tube 3 is tapered, thereby improving the penetration performance of the catheter body 1 as it follows the guidewire 4 through the obstruction zone 12.

[0068] The balloon compliance mentioned in the above embodiments refers to the change in the balloon's shape or volume with each increase of one atmosphere (atm) during inflation. It is an indicator of the balloon's tensile strength. The higher the balloon compliance after full inflation, the more pronounced the trend of further increase in balloon volume or shape with continued increase in inflation pressure. In clinical applications, compliant balloons are typically used for fixation along blood vessels, while non-compliant and semi-compliant balloons are typically used for vascular dilation or pre-dilation. Furthermore, the internal details of the stent and operating handle utilize existing technology. Those skilled in the art should understand that these details will not be elaborated upon here.

[0069] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A microcatheter for chronic total occlusion of an artery, comprising a catheter body (1), characterized in that: The catheter body (1) includes an inner tube (3) and an outer tube (2). The outer tube (2) is sleeved outside the inner tube (3) and is slidably connected to the inner tube (3). A guidewire cavity (101) is provided inside the inner tube (3), and a guidewire (4) is inserted inside the guidewire cavity (101). The inner tube (3) is provided with a first balloon (5) and a second balloon (6) on its outer wall. The first balloon (5) is located at the front end of the inner tube (3), and the second balloon (6) is located behind the first balloon (5). The inner tube (3) is provided with a first injection chamber (102) and a second injection chamber (103). The front end of the first injection chamber (102) is connected to the interior of the first balloon (5), and the front end of the second injection chamber (103) is connected to the interior of the second balloon (6). The rear end of the catheter body (1) is provided with an operating handle (8), and the operating handle (8) is provided with a first injection port (801), a second injection port (802) and a guidewire delivery port (803). The rear end of the first injection cavity (102) is connected to the first injection port (801), the rear end of the second injection cavity (103) is connected to the second injection port (802), and the rear end of the guidewire cavity (101) is connected to the guidewire delivery port (803). The second balloon (6) is fitted with a stent (7) on its outer side; The outer tube (2) is located behind the first balloon (5), and there is a gap between the rear end of the outer tube (2) and the front end of the operating handle (8); the second balloon (6) and the stent (7) are located between the outer tube (2) and the inner tube (3).

2. The microcatheter for chronic total occlusion of an artery according to claim 1, characterized in that: The inner tube (3) has a contrast agent embedded at the position of the second balloon (6) and / or the front end position.

3. The microcatheter for chronic total occlusion of an artery according to claim 1, characterized in that: A pull tab (9) is fixedly installed at the rear end of the outer wall of the outer tube (2).

4. A microcatheter for chronic total occlusion of an artery according to claim 1, characterized in that: A limiting sleeve (10) is fitted on the inner tube (3). The limiting sleeve (10) has a through opening on its wall. The limiting sleeve (10) is located between the outer tube (2) and the operating handle (8).

5. A microcatheter for chronic total occlusion of an artery according to claim 1, characterized in that: The first balloon (5) is a compliant balloon or a semi-compliant balloon, and the second balloon (6) is a non-compliant balloon.

6. A microcatheter for chronic total occlusion of an artery according to claim 1, characterized in that: The front end of the inner tube (3) is tapered.

Images