Micro-catheter for chronic complete arterial occlusion and use method of micro-catheter

Abstract

The invention provides a micro catheter for chronic complete arterial occlusion and a using method thereof. The micro catheter comprises a catheter body, a guide wire cavity is formed in the catheter body, an operating handle is arranged at the rear end of the catheter body, and a guide wire is arranged in the guide wire cavity in a penetrating mode; the catheter body comprises an inner tube and an outer tube; the inner tube is sleeved with the outer tube, a first balloon and a second balloon are arranged on the inner tube, and the second balloon is sleeved with a support; a first injection cavity and a second injection cavity are formed in the inner tube, the first injection cavity is communicated with the first balloon, and the second injection cavity is communicated with the second balloon; the front end of the outer tube abuts against the first balloon, and a gap is formed between the outer tube and the operation handle. The second balloon and the stent are located between the outer tube and the inner tube. According to the micro-catheter, the stent is arranged on the inner tube, puncture, expansion and stent implantation can be completed in one step without withdrawing the micro-catheter, and the technical problems that in the prior art, the withdrawing step of the micro-catheter is tedious, and a guide wire is difficult to move and the stent is difficult to feed when the micro-catheter is withdrawn are solved.

Description

Technical Field

[0001] The present invention relates to the field of human necessities, particularly to the field of medical auxiliary devices, and more particularly to a microcatheter for chronic total occlusion of arteries and its usage method. Background Art

[0002] Chronic total occlusion (CTO) lesions refer to arterial lesions with an occlusion time of up to 3 months or more, commonly found in arteries, peripheral arteries, etc. Among patients diagnosed by angiography, the proportion of such lesions is as high as 15% to 25%. Due to calcification of some tissues at the CTO lesion site, it is very difficult to open the CTO lesion, which has always been regarded as a huge challenge for PCI (percutaneous coronary intervention) technology and even known as the "last fortress" in this field.

[0003] Most CTOs cannot directly penetrate the obstruction area with a guide wire, and thus a microcatheter needs to be used for assistance. A hard guide wire (such as Conquest Pro) is inserted into the microcatheter, and with the help of "lever force" to increase the penetration force, combined with techniques such as rotation or using a guide wire with a special tip to penetrate the obstruction area. After penetration, a stent can be implanted at the penetration position to unblock the artery.

[0004] In the prior art, the steps for CTO stent implantation are generally as follows: First, push the microcatheter to the proximal end of the obstruction area to assist the hard guide wire to penetrate the obstruction area. After confirming that the guide wire has penetrated, fix the guide wire and slowly withdraw the microcatheter to avoid displacement of the guide wire. Finally, pass the stent delivery system along the guide wire to deliver the stent to the target position, and expand the balloon to release the stent to complete the implantation of the stent.

[0005] However, the prior art has the following defects: After the microcatheter assists the guide wire to penetrate the obstruction area, the guide wire needs to be fixed, and the microcatheter is slowly withdrawn. Then, the stent is sent along the guide wire to the target position. During the operation, the microcatheter and the stent alternately enter and exit the blood vessel, with cumbersome steps, which easily increases the risk of blood vessel injury and leads to an increase in the surgical risk.

[0006] When the microcatheter is withdrawn, the guide wire needs to be fixed in place. Once the guide wire displaces away from the obstruction area, re-puncturing is required; and the guide wire is very thin, and the movement of the microcatheter is very likely to drive the movement of the guide wire, resulting in a very low tolerance for the operation of withdrawing the microcatheter, an increase in uncertain factors, and very difficult operation.

[0007] When the stent is delivered in the blood vessel, the stent directly contacts the blood vessel wall. Compared with the microcatheter or guide wire with a lubricating coating, the resistance of the stent during delivery in the blood vessel is greater, and it is prone to blockage during delivery or cannot be sent to the target position at one time, resulting in an increased risk of perforation. Summary of the Invention

[0008] The object of the present invention is to provide a microcatheter for chronic total occlusion of an artery. The microcatheter for chronic total occlusion of an artery has a stent on its inner tube, and puncture, dilation and stent implantation can be completed in one step without withdrawing the microcatheter, thereby solving the technical problems in the prior art of complicated microcatheter withdrawal steps, easy movement of the guide wire during microcatheter withdrawal and difficulty in delivering the stent.

[0009] A microcatheter for chronic total occlusion of an artery comprises a catheter body, wherein the catheter body comprises an inner tube and an outer tube, wherein the outer tube is sleeved outside the inner tube and the outer tube is slidably connected to the inner tube; a guidewire cavity is arranged inside the inner tube, and a guidewire is passed through the guidewire cavity; a first balloon and a second balloon are arranged on the outer wall of the inner tube, wherein the first balloon is located at the front end of the inner tube, and the second balloon is located at the rear of the first balloon; a first injection cavity and a second injection cavity are arranged in the inner tube, wherein the front end of the first injection cavity is communicated with the interior of the first balloon, and the second injection cavity is connected to the front end of the first injection cavity. The front end is connected with the interior of the second balloon; the rear end of the catheter body is provided with an operating handle, and the operating handle is provided with a first injection port, a second injection port and a guide wire delivery port, the rear end of the first injection cavity is connected with the first injection port, the rear end of the second injection cavity is connected with the second injection port, and the rear end of the guide wire cavity is connected with the guide wire delivery port; the outer side of the second balloon is sleeved with a stent; the outer tube is located behind the first balloon, and a distance is set between the rear end of the outer tube and the front end of the operating handle; the second balloon and the stent are located between the outer tube and the inner tube.

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

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

[0012] Furthermore, a limiting sleeve is sleeved on the inner tube, an opening penetrating from front to back is opened on the tube wall of the limiting sleeve, and the limiting sleeve 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 present invention also provides a method for using the microcatheter for chronic total occlusion of arteries, comprising the following steps: Step 1: insert the catheter body into a blood vessel so that the front end of the catheter body is close to the obstruction area in the blood vessel.

[0016] Step 2: Push the front end of the guide wire out of the inner tube and penetrate the obstruction area.

[0017] Step 3: Push the catheter body forward along the path penetrated by the guide wire, so that the catheter body penetrates the obstruction area.

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

[0019] Step 5: Inflate the first balloon, make the outer side of the first balloon abut against the inner wall of the blood vessel, and relatively fix the inner tube and the blood vessel.

[0020] Step 6: Retract the outer tube backward while keeping the position of the inner tube, so as to expose the stent and the second balloon.

[0021] Step 7: Inflate the second balloon, and the stent expands as the second balloon inflates, realizing the dilation of the blood vessel in the obstruction area.

[0022] Step 8: Deflate the first balloon and deflate the second balloon.

[0023] Step 9: Withdraw the catheter body.

[0024] Further, between Step 3 and Step 4, the following steps are further included: Step 301: Move the catheter body forward so that the first balloon is located at the obstruction area, inflate the first balloon, pre-dilate the blood vessel in the obstruction area, and after dilation, deflate the first balloon.

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

[0026] Furthermore, the specific method for inflating the first balloon is as follows: Use an injection pump to inject a contrast agent into the first injection port, and the contrast agent enters the first balloon through the first injection cavity, so that the first balloon inflates.

[0027] Furthermore, the specific method for inflating the second balloon is as follows: Use an injection pump to inject a contrast agent into the second injection port, and the contrast agent enters the second balloon through the second injection cavity, so that the second balloon inflates.

[0028] Compared with the existing technology, the effect of the present invention is positive and obvious: The microcatheter of the present invention is equipped with a stent. Compared with the traditional CTO microcatheter, the present invention completes all steps such as puncture, dilation, and stent implantation at one time, with high surgical efficiency and simple operation.

[0029] After the guide wire penetrates the obstruction area in the present invention, the microcatheter can deploy the stent through the second balloon without being withdrawn from the blood vessel, greatly reducing the surgical risks such as perforation caused by the repeated entry and exit of the microcatheter into and out of the blood vessel.

[0030] In the present invention, the stent 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, providing better advancement and reducing the risks of stent blockage and blood vessel perforation. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 . Schematic structural diagram of Embodiment 1 in the present invention.

[0032] Figure 2 . Schematic structural diagram of the front end of the catheter body corresponding to Step 2 in Embodiment 1 of the present invention.

[0033] Figure 3 . Schematic structural diagram of the front end of the catheter body corresponding to Step 5 in Embodiment 1 of the present invention.

[0034] Figure 4 . Schematic structural diagram of the front end of the catheter body corresponding to Step 6 in Embodiment 1 of the present invention.

[0035] Figure 5 . Schematic vertical cross-sectional diagram of Embodiment 1 in the present invention.

[0036] Figure 6 . Schematic cross-sectional diagram of Embodiment 1 in the present invention.

[0037] Figure 7 . Schematic operation diagram of Step 1 in Embodiment 1 of the present invention.

[0038] Figure 8 . Schematic operation diagram of Step 2 in Embodiment 1 of the present invention.

[0039] Figure 9 . Schematic operation diagram of Step 3 in Embodiment 1 of the present invention.

[0040] Figure 10 . Schematic operation diagram of Step 4 in Embodiment 1 of the present invention.

[0041] Figure 11 . Schematic operation diagram of Step 5 in Embodiment 1 of the present invention.

[0042] Figure 12 . Schematic operation diagram of Step 6 in Embodiment 1 of the present invention.

[0043] Figure 13 . Schematic operation diagram of Step 7 in Embodiment 1 of the present invention.

[0044] Figure 14 .Schematic diagram of the structure of the front end of the catheter body of Example 3 of the present invention.

[0045] In the figure: 1. catheter body; 101. guidewire cavity; 102. first injection cavity; 103. second injection cavity; 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. pull tab; 10. limiting sleeve; 11. blood vessel wall; 12. obstruction area. DETAILED DESCRIPTION

[0046] The present invention will be further described in the following examples, but the present invention is not limited thereto. Example

[0047] like Figures 1 to 6 As shown, this embodiment provides a microcatheter for chronic total occlusion of an artery, comprising 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 the outer tube 2 is slidably connected to the inner tube 3. The outer wall of the outer tube 2 is smooth and has a hydrophilic lubricating coating, so that the outer tube 2 has good lubricity and passability. A guidewire cavity 101 is provided in the inner tube 3, and a guidewire 4 is passed through the guidewire cavity 101.

[0049] The outer wall of the inner tube 3 is provided with a first balloon 5 and a second balloon 6, 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 abut against the blood vessel to fix the position of the inner tube 3, and the second balloon 6 is used to expand 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 accordingly according to the needs.

[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; a first injection cavity 102 and a second injection cavity 103 are respectively arranged in the inner tube 3 along its extension direction, the front end of the first injection cavity 102 is connected to the interior of the first balloon 5, and the front end of the second injection cavity 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, and a first injection port 801, a second injection port 802 and a guide wire delivery port 803 are provided on the operating handle 8. The first injection port 801, the second injection port 802 and the guide wire 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 guide wire cavity 101 is connected to the guide wire delivery port 803.

[0052] The front end of the outer tube 2 abuts against the rear end of the first balloon 5. There is a certain distance between the rear end of the outer tube 2 and the front end of the operating handle 8, and this distance provides 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 wraps around the second balloon 6 and the stent 7.

[0053] A pull tab 9 is fixedly arranged at the rear end of the outer wall of the outer tube 2, which is convenient to be used as a force application point for retracting the outer tube 2 backward. A limiting sleeve 10 is sleeved 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, and prevent the outer tube 2 from sliding backward during the process of the catheter body 1 penetrating into the blood vessel; a through opening is formed in the tube wall of the limiting sleeve 10, and the limiting sleeve 10 can be peeled off from the inner tube 3 through this opening, so as to release the space for the outer tube 2 to move backward along the inner tube 3, which is convenient for the outer tube 2 to retreat.

[0054] The inner tube 3 is embedded with a contrast agent at the position of the second balloon 6 and the front end position of the inner tube 3 as a visualization point, so that it is easier to observe the position of the front end of the inner tube 3 and the position of the second balloon 6 (that is, the stent 7) under fluoroscopy, which is convenient for more accurately penetrating the obstruction area 12 and placing the stent 7 in the obstruction area 12.

[0055] This embodiment also provides a method for using the above-mentioned microcatheter for chronic total occlusion of arteries, which includes the following steps: Step 1: As Figure 7 shown, ensure that the catheter body 1 is in the initial state, the first balloon 5, the second balloon 6 and the stent 7 are all in the contracted state, and the outer tube 2 wraps around the stent 7 and the second balloon 6. This can not only protect the stent 7 and the second balloon 6, but also improve the passing performance of the catheter body 1 in the blood vessel. Introduce the catheter body 1 in the initial state into the blood vessel, and make the front end of the catheter body 1 approach the obstruction area 12 in the blood vessel.

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

[0057] Step 3: As Figure 9 shown, the catheter body 1 advances along the path penetrated by the guide wire 4, 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 at the obstruction area 12.

[0059] Step 5: As Figure 10 shown, use an injection pump to inject a contrast agent into the first injection port 801. The contrast agent enters the first balloon 5 through the first injection cavity 102, so that the first balloon 5 expands. After the first balloon 5 expands, the outer side of the first balloon 5 abuts against the inner wall of the blood vessel, so that the inner tube 3 is relatively fixed to the blood vessel.

[0060] Step 6: As Figure 11 shown, retract the outer tube 2 backward, but keep the position of the inner tube 3 unchanged, so as to expose the stent 7 and the second balloon 6.

[0061] Step 7: As Figure 12 shown, use an injection pump to inject a contrast agent into the second injection port 802. The contrast agent enters the second balloon 6 through the second injection cavity 103, causing the second balloon 6 to expand. After the second balloon 6 expands, the stent 7 expands with the expansion of the second balloon 6, realizing the dilation of the obstruction area 12.

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

[0063] Step 9: Retract the catheter body 1 backward to withdraw the catheter body 1 out of the body, and complete the operation at the end. Embodiment

[0064] This embodiment is an optimized scheme of Embodiment 1. The first balloon 5 is a semi-compliant balloon. The semi-compliant balloon can precisely regulate the balloon diameter by controlling the pressure after filling exceeds the nominal pressure, so that it can not only abut against the blood vessel but also continuously increase the pressure to pre-dilate the blood vessel obstruction area 12, achieving a multi-purpose effect.

[0065] In the usage method of Embodiment 1, the following steps are added between Step 3 and Step 4 to realize 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 a 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 expand. After the first balloon 5 expands, pre-dilate the obstruction area 12. After dilation, the first balloon 5 contracts.

[0066] Step 302: When obvious calcification is seen in the artery of the blood vessel wall 11 under fluoroscopy, Step 301 can be repeated multiple times until the expected pre-dilation effect is achieved. When the dilation pressure of the semi-compliant first balloon 5 increases to 16 atm or exceeds the balloon burst pressure and still cannot make the lesion indentation disappear, consideration should be given to replacing it with a cutting balloon or using atherectomy, and the balloon pressure should not be continuously increased to avoid serious complications such as blood vessel rupture and perforation. Embodiment

[0067] As Figure 14 shown, this embodiment is an optimized scheme of Embodiment 1. The front end of the inner tube 3 is conical, so as to improve the penetration performance of the catheter body 1 following the guide wire 4 through the obstruction area 12.

[0068] The compliance of the balloon mentioned in the above embodiments refers to the change in the shape or volume of the balloon corresponding to each increase in one atmosphere (atm) when the balloon is inflated, which is an index of the balloon's stretching ability. After the balloon is fully inflated, the higher the compliance of the balloon, the more obvious the trend of further increase in the volume or shape of the balloon as the inflation pressure continues to increase. In clinical applications, compliant balloons are usually used for fixation by conforming to blood vessels, and non-compliant balloons and semi-compliant balloons are usually used for blood vessel dilation or pre-dilation. In addition, the internal details of the stent and the operating handle adopt existing technologies. Those skilled in the art should understand and will not be elaborated here.

[0069] Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions 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) comprises an inner tube (3) and an outer tube (2), wherein the outer tube (2) is sleeved outside the inner tube (3), and the outer tube (2) is slidably connected to the inner tube (3); a guidewire cavity (101) is provided in the inner tube (3), and a guidewire (4) is passed through the guidewire cavity (101); A first balloon (5) and a second balloon (6) are arranged on the outer wall of the inner tube (3), wherein 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); A first injection cavity (102) and a second injection cavity (103) are provided in the inner tube (3); the front end of the first injection cavity (102) is communicated with the interior of the first balloon (5), and the front end of the second injection cavity (103) is communicated with 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 guide wire delivery port (803); the rear end of the first injection cavity (102) is communicated with the first injection port (801), the rear end of the second injection cavity (103) is communicated with the second injection port (802), and the rear end of the guide wire cavity (101) is communicated with the guide wire delivery port (803); The outer side of the second balloon (6) is provided with a stent (7); The outer tube (2) is located behind the first balloon (5), and a distance is provided between the rear end of the outer tube (2) and the front end of the operating handle (8); the second balloon (6) and the bracket (7) are located between the outer tube (2) and the inner tube (3).

2. A microcatheter for chronic total occlusion of arteries according to claim 1, characterized in that: The inner tube (3) is embedded with a developer at the position of the second balloon (6) and / or at the front end position.

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

4. The microcatheter for chronic total occlusion of arteries according to claim 1, characterized in that: A limiting sleeve (10) is sleeved on the inner tube (3), a tube wall of the limiting sleeve (10) is provided with an opening that passes through from front to back, and the limiting sleeve (10) is located between the outer tube (2) and the operating handle (8).

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

7. A method for using a microcatheter for chronic total occlusion of arteries as described in claim 1, characterized in that: The following steps are involved: Step 1: inserting the catheter body (1) into a blood vessel so that the front end of the catheter body (1) is close to the obstruction area (12) in the blood vessel; Step 2: Push the front end of the guide wire (4) out of the inner tube (3) and penetrate the obstruction area (12). Step 3: Push the catheter body (1) forward along the path penetrated by the guide wire (4) so that the catheter body (1) penetrates the obstruction area (12). Step 4: Move the catheter body (1) forward so that the second balloon (6) is located at the obstruction area (12). Step 5: Inflate the first balloon (5), and make the outer side of the first balloon (5) abut against the inner wall of the blood vessel, so that the inner tube (3) is relatively fixed to the blood vessel. Step 6: Retract the outer tube (2) backward while keeping the position of the inner tube (3), thereby exposing the stent (7) and the second balloon (6). Step 7: Inflate the second balloon (6), and make the stent (7) expand with the inflation of the second balloon (6) to achieve the dilation of the blood vessel in the obstruction area (12). Step 8: Deflate the first balloon (5) and deflate the second balloon (6). Step 9: Withdraw the catheter body (1).

8. The method for using a microcatheter for chronic total occlusion of arteries according to claim 7, characterized in that: Between Step 3 and Step 4, the following steps are further included: Step 301: Move the catheter body (1) forward so that the first balloon (5) is located at the obstruction area (12), inflate the first balloon (5), pre-dilate the blood vessel in the obstruction area (12), and after dilation, deflate the first balloon (5). Step 302: When obvious calcification is seen in the artery of the blood vessel wall (11) under fluoroscopy, repeat Step 301 multiple times until the expected pre-dilation effect is achieved.

9. The method for using the microcatheter for chronic total occlusion of artery according to claim 7 or 8, characterized in that: The specific method for inflating the first balloon (5) is as follows: Use an injection pump to inject a contrast agent into the first injection port (801), and the contrast agent enters the first balloon (5) through the first injection cavity (102) to inflate the first balloon (5).

10. The method for using a microcatheter for chronic total occlusion of arteries according to claim 7, characterized in that: The specific method for inflating the second balloon (6) is as follows: Use an injection pump to inject a contrast agent into the second injection port (802), and the contrast agent enters the second balloon (6) through the second injection cavity (103) to inflate the second balloon (6).

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