Tissue expansion catheter with fixation structure

Abstract

The present application relates to the technical field of medical devices, in particular to a tissue expansion catheter with a fixing structure. The tissue expansion catheter comprises an outer tube and an inner tube, the inner tube is arranged in the outer tube, the end of the outer tube is fixedly connected with a communication member fixedly connected with the inner tube, the communication member is fixedly connected with an expansion outer cylinder and an expansion inner cylinder, and the three members together form a filling cavity, the expansion inner cylinder is fixedly connected with an inner support body which is annularly distributed and in contact with the inner tube, and the side of the inner support body away from the inner tube penetrates through the expansion inner cylinder and is provided with two groups of protrusions which are symmetrically distributed. The present application utilizes the protrusions to pull the inner side of the expansion outer cylinder, so that the surface of the expansion outer cylinder after expansion generates a pit, and then when the expansion outer cylinder is expanded and pressed at a lesion position, the lesion tissue is embedded in the pit on the surface of the expansion outer cylinder, thereby inhibiting the sliding of the expansion outer cylinder caused by the pressing, and at the same time maintaining the smoothness of the surface of the expansion outer cylinder in the retracted state, which is beneficial to the movement of the expansion outer cylinder in the patient's body.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a tissue expansion catheter with a fixing structure. BACKGROUND

[0002] Balloon catheter is a key interventional medical device, which is usually used to expand the narrow or blocked part in blood vessels; its basic working principle is to exert radial force on the blood vessel wall by inflating the balloon, so as to restore the blood flow channel. Since the balloon part of the balloon expansion catheter is usually a smooth balloon, in the blood vessel expansion process, if a hard calcified lesion is encountered, the conventional balloon is prone to displacement during the pressurization process due to extrusion by the lesion, thereby deviating from the target position and resulting in ineffective expansion of the blood vessel. In order to solve this problem, in recent years, a papillary balloon with multiple papillary structures distributed on the surface has appeared. These papillae can increase the friction between the balloon and the lesion, play a role in preventing slipping, and ensure that the balloon does not move when expanding the blood vessel.

[0003] However, the papillary structure of the conventional papillary balloon is directly arranged on the surface of the balloon. Although it increases the friction between the balloon and the lesion when the balloon is inflated, it also increases the surface roughness of the balloon in the collapsed state, which is not conducive to the movement of the balloon catheter in the patient's body. Such rough surface can increase the resistance when passing through the tortuous blood vessels during catheter delivery, and even cause intimal injury or spasm. In addition, the increase in roughness also increases the friction between the catheter and the delivery system, affecting the operation feel and positioning accuracy, and in severe cases, it may even cause the balloon to be difficult to reach the intended lesion position. SUMMARY

[0004] The present application provides a tissue expansion catheter with a fixing structure to overcome the shortcomings of conventional papillary balloons, which have high surface roughness and are not convenient to move in blood vessels.

[0005] The technical scheme is as follows: a tissue expansion catheter with a fixing structure, comprising an outer tube and an inner tube, the inner tube is arranged in the outer tube, the end of the outer tube is fixedly connected with a communicating member fixedly connected with the inner tube, the communicating member is fixedly connected with an expansion outer cylinder and an expansion inner cylinder, and the communicating member, the expansion outer cylinder and the expansion inner cylinder jointly form a filling cavity, the expansion outer cylinder is fixedly connected with the expansion inner cylinder away from the communicating member, the expansion inner cylinder is fixedly connected with an inner support body which is annularly distributed and in contact with the inner tube, the inner support body away from the inner tube penetrates through the expansion inner cylinder and is provided with two groups of protrusions which are symmetrically distributed, each group of the protrusions comprises a plurality of protrusions which are equidistantly distributed, the protrusions are fixedly connected with the expansion outer cylinder, and are used for pulling the expansion outer cylinder to form a pit on the surface of the expansion outer cylinder when the expansion outer cylinder is inflated, the inner support body and the expansion inner cylinder jointly form a supporting cavity, the expansion inner cylinder is provided with arc-shaped holes which are annularly distributed, the number of the arc-shaped holes is equal to the number of the inner support body, and the supporting cavity is communicated with the filling cavity through the adjacent arc-shaped holes.

[0006] Further, the arc-shaped holes are located on the side of the expansion inner cylinder away from the communicating member.

[0007] Further, the communicating member, the expansion outer cylinder and the expansion inner cylinder are all made of hydrophilic material, so that the gas existing in the filling cavity can be extruded into the supporting cavity.

[0008] Further, the communicating member is provided with flow-through holes which are annularly distributed and used for blood flow.

[0009] Further, the number of the flow-through holes is equal to the number of the inner support body, and all the inner support bodies and all the flow-through holes are staggered.

[0010] Further, the end of the inner tube is fixedly connected with a mounting cylinder, the mounting cylinder is fixedly connected with guide pieces which are annularly distributed, the guide pieces are fixedly connected with the expansion outer cylinder, and the guide pieces are used for guiding the expansion outer cylinder to move in the blood vessel.

[0011] Further, the guide pieces are made of elastic material, when the expansion outer cylinder and the expansion inner cylinder are inflated, the guide pieces are in a stretched state, and when the expansion outer cylinder and the expansion inner cylinder are contracted, the guide pieces are in a free state.

[0012] Further, the number of the guide pieces is equal to the number of the flow-through holes, and all the flow-through holes and all the guide pieces are staggered.

[0013] Further, the section of the mounting cylinder away from the expansion outer cylinder is in the shape of a circular arc.

[0014] Further, the outer side of the expansion outer tube, the inner side of the expansion inner tube and the outer side of the inner support are coated with a PTFE coating to inhibit platelet adhesion.

[0015] The beneficial effects produced by the above technical solutions are that the invention uses the protrusions to pull the inner side of the expansion outer tube, so that the surface of the expansion outer tube after expansion has pits, and then when the expansion outer tube is expanded and pressed at the lesion site, the lesion tissue is embedded in the pits on the surface of the expansion outer tube, thereby inhibiting the sliding of the expansion outer tube caused by the pressing, while maintaining the smoothness of the surface of the expansion outer tube in the collapsed state, which is beneficial to the movement of the expansion outer tube in the patient's body.

[0016] The gaps and flow-through holes of all the inner supports provide a flow channel for blood, avoiding the obstruction of the blood vessel by the balloon expansion, thus prolonging the time of single expansion and improving the expansion effect on the lesion site.

[0017] The use of the guide pieces to pull the expansion outer tube allows the expansion outer tube to be close to the surface of the inner tube when it is collapsed, and then the expansion outer tube is uniformly collapsed, so that the maximum outer diameter of the balloon catheter in the collapsed state is controlled, which is convenient for the movement of the balloon catheter in the patient's body. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a schematic diagram of the three-dimensional structure of the invention;

[0019] Figure 2 is a schematic diagram of the three-dimensional structure of the communication piece and the inner support of the invention;

[0020] Figure 3 is a schematic diagram of the three-dimensional structure of the expansion outer tube and the expansion inner tube of the invention;

[0021] Figure 4 is a schematic diagram of the three-dimensional structure of the communication piece and the expansion outer tube of the invention;

[0022] Figure 5 is an enlarged view of part A in the invention; Figure 2

[0023] Figure 6 is an exploded view of the communication piece, the expansion outer tube and the expansion inner tube of the invention.

[0024] Label name in the figure: 1, outer tube, 2, inner tube, 3, communication piece, 301, flow-through hole, 4, expansion outer tube, 5, expansion inner tube, 501, filling cavity, 502, arc-shaped hole, 6, inner support, 601, protrusion, 602, support cavity, 7, mounting tube, 8, guide piece. DETAILED DESCRIPTION

[0025] ​The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of the present application.

[0026] Embodiment 1

[0027] The embodiment provides a tissue expansion catheter with a fixing structure to reduce the moving resistance of a balloon catheter in a patient's body.

[0028] The current papillary balloon catheter has a rough surface in the collapsed state due to the papillary structure on the surface, which is not conducive to the movement of the balloon catheter in the patient's body.

[0029] Referring to Figures 1 to 4 and Figure 6 A tissue expansion catheter with a fixing structure comprises an outer tube 1 and an inner tube 2, the inner tube 2 is arranged in the outer tube 1, the inner tube 2 is used for passing a guide wire, the outer tube 1 and the inner tube 2 form a delivery channel, and the delivery channel is communicated with an external pressure pump, and contrast medium is injected into the delivery channel through the pressure pump; the end of the left side of the outer tube 1 is fixedly connected with a communicating member 3, the communicating member 3 is composed of an inner-outer double-layer circular truncated cone barrel, so that the end face of the communicating member 3 has an inner ring and an outer ring, the inner ring of the right part of the communicating member 3 is fixedly connected with the inner tube 2, so that the delivery channel is communicated with the inside of the communicating member 3; the outer ring and the inner ring of the left side of the communicating member 3 are fixedly connected with an expansion outer barrel 4 and an expansion inner barrel 5 respectively, the left side of the expansion outer barrel 4 is fixedly connected with the left side of the expansion inner barrel 5, the communicating member 3, the expansion outer barrel 4 and the expansion inner barrel 5 jointly form a filling cavity 501, the expansion inner barrel 5 is fixedly connected with three inner support bodies 6 distributed in a ring shape, the inner support body 6 and the expansion inner barrel 5 jointly form a support cavity 602, the expansion inner barrel 5 is provided with three arc-shaped holes 502 distributed in a ring shape, the support cavity 602 is communicated with the filling cavity 501 through adjacent arc-shaped holes 502, the inner support body 6 is in contact with the inner tube 2, when the inner support body 6 is inflated, the inner side of the inner support body 6 abuts against the inner tube 2, so as to provide support for the expansion outer barrel 4 and the expansion inner barrel 5; the side, away from the inner tube 2, of the inner support body 6 passes through the expansion inner barrel 5 and is provided with two groups of protrusions 601 distributed symmetrically, each group of protrusions 601 comprises a plurality of protrusions 601 distributed at equal intervals, the protrusions 601 are fixedly connected with the expansion outer barrel 4, the number and the interval of the protrusions 601 are determined by the axial length of the expansion outer barrel 4 and the flexibility of the material thereof, and the protrusions 601 are used to pull the expansion outer barrel 4 when the expansion outer barrel 4 is inflated, so that the surface of the expansion outer barrel 4 forms a pit (see Figure 1 ).

[0030] The above arrangement can achieve that, by using the protrusions 601 to pull the inside of the expansion outer tube 4, the surface of the expanded expansion outer tube 4 is concave, and then when the expansion outer tube 4 is expanded and pressed at the lesion position, the lesion tissue is embedded in the concave of the surface of the expansion outer tube 4, and then the sliding of the expansion outer tube 4 caused by the pressing is inhibited, and the smoothness of the surface of the expansion outer tube 4 in the collapsed state is maintained, which is beneficial to the movement of the expansion outer tube 4 in the patient's body.

[0031] During the process of injecting the contrast agent into the filling cavity 501 through the delivery channel by the pressure pump, the contrast agent gradually fills the filling cavity 501 and the support cavity 602, so that the expansion outer tube 4, the expansion inner tube 5 and the inner support 6 are all changed from the collapsed state to the expanded state. Under the pressure of the contrast agent, the expansion inner tube 5 and the inner support 6 expand inward, and the expansion outer tube 4 expands outward, but the expansion inner tube 5 and the inner support 6 pull the expansion outer tube 4 through all the protrusions 601, so that the position where the expansion outer tube 4 is fixed with the protrusions 601 is concave, thereby inhibiting the sliding of the expansion outer tube 4 relative to the lesion position.

[0032] Embodiment 2

[0033] This embodiment provides a function of accumulating air remaining in the balloon catheter to improve the imaging effect on the basis of embodiment 1.

[0034] Because of the gas in the balloon catheter, it is necessary to first extract the gas in the balloon catheter before injecting the contrast agent into the balloon catheter by the pressure pump, but the process is complex and is not conducive to improving the operation efficiency.

[0035] Referring to Figures 2 to 4 The arc-shaped hole 502 is located at the left part of the expansion inner tube 5 and controls the order of filling of the contrast agent in the filling cavity 501 and the support cavity 602. The communication member 3, the expansion outer tube 4 and the expansion inner tube 5 are all hydrophilic materials, which use the hydrophilic property to enhance the adhesion effect of the contrast agent to the side wall of the filling cavity 501, thereby inhibiting the flow of gas into the contrast agent, and helping to keep the gas-liquid interface of the contrast agent and the gas in the filling cavity 501 and the support cavity 602 stable.

[0036] During the process of injecting the contrast agent into the filling cavity 501, the contrast agent can ignore the effect of gravity under the action of surface tension and gradually fills the filling cavity 501 from right to left, and the gas existing in the delivery channel and the filling cavity 501 is pressed into the support cavity 602. After the filling cavity 501 is completely filled with the contrast agent, the contrast agent flows into the support cavity 602 through the arc-shaped hole 502, and all the gas is pressed to the end of the support cavity 602, so that the filling ratio of the contrast agent in the filling cavity 501 is maintained, and the imaging effect is improved.

[0037] Embodiment 3

[0038] This embodiment improves the expansion effect on the blood vessels on the basis of embodiment 2.

[0039] The existing balloon in the process of inflation, the papillary structure will block the blood vessels, causing downstream tissue ischemia, therefore, the clinical application of balloon single inflation time is strictly limited to avoid long time occlusion caused by tissue damage, but the short inflation time will make the blood vessel wall can not be fully plastic deformation, after the balloon retraction, the blood vessel is easy to shrink under the action of elasticity, thus resulting in the expansion effect of the lesion site is not ideal.

[0040] Referring to Figures 1 to 4 , the communication piece 3 is provided with three flow holes 301 distributed in a ring shape, and the flow holes 301 are used for blood flow; all the inner supports 6 are staggered with all the flow holes 301.

[0041] The above setting can provide a flow channel for blood by using the gaps of all the inner supports 6 and the flow holes 301, avoid the balloon inflation to block the blood vessels, thus prolong the single inflation time and improve the expansion effect of the lesion site.

[0042] Embodiment 4

[0043] This embodiment provides a function of guiding the balloon to contract on the basis of embodiment 3.

[0044] The balloon catheter used at present is in a circumferentially uniform folded and wound state when it is produced, but when it is inflated in the patient's body and then shrinks, the state of the balloon after shrinking cannot be controlled, and the balloon may be directly sucked flat but the width is larger than that when it is inflated, so that the balloon moving in the patient's body will increase the patient's discomfort.

[0045] Referring to Figure 1 , Figure 2 , Figure 5 and Figure 6 , the left end of the inner tube 2 is fixedly connected with a mounting cylinder 7, the left side of the cross section of the mounting cylinder 7 is a circular arc shape, which reduces the probability of scratching the blood vessels by the mounting cylinder 7; the right side of the mounting cylinder 7 is fixedly connected with three guide pieces 8 distributed in a ring shape, the guide pieces 8 are fixedly connected with the expansion outer cylinder 4, the guide pieces 8 are made of elastic material, and the guide pieces 8 are used for guiding the expansion outer cylinder 4 to move in the blood vessels; the communication piece 3, the expansion outer cylinder 4 and the three guide pieces 8 form a shuttle shape, which facilitates the movement of the balloon catheter in the patient's body.

[0046] Referring to Figure 1 and Figure 2 , when the expansion outer cylinder 4 and the expansion inner cylinder 5 are inflated, the guide pieces 8 are in a stretched state, and when the expansion outer cylinder 4 and the expansion inner cylinder 5 are contracted, the guide pieces 8 are in a free state (the free state here means a state without force); the number of the guide pieces 8 is equal to the number of the flow holes 301, and all the flow holes 301 are staggered with all the guide pieces 8.

[0047] The above arrangement can achieve that the expansion outer tube 4 is pulled by the guide piece 8, so that the expansion outer tube 4 can be close to the surface of the inner tube 2 when being folded, and then the expansion outer tube 4 is uniformly folded, so that the maximum outer diameter of the balloon catheter in the folded state is controlled, and the balloon catheter is facilitated to move in the patient's body.

[0048] Embodiment 5

[0049] This embodiment provides the function of inhibiting thrombosis on the basis of the embodiment 4.

[0050] Referring to Figure 1 The outer side of the expansion outer tube 4, the inner side of the expansion inner tube 5 and the outer side of the inner support 6 are coated with a PTFE coating, and the PTFE coating provides good biocompatibility lubricity, reduces the friction with the tissue and blood, reduces the discomfort of the patient, and inhibits the adhesion of platelets and reduces the risk of thrombosis.

[0051] The above-described embodiments are only used to illustrate the technical solutions of the present application, but not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced by equivalent ones; 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 application.

Claims

1. A tissue dilation catheter with a fixed structure, characterized in that, include: An outer tube (1) and an inner tube (2) are provided, the inner tube (2) being disposed inside the outer tube (1). The end of the outer tube (1) is fixedly connected to a connecting member (3) which is fixedly connected to the inner tube (2). The connecting member (3) is fixedly connected to an expanding outer cylinder (4) and an expanding inner cylinder (5). The connecting member (3), the expanding outer cylinder (4), and the expanding inner cylinder (5) together form a filling cavity (501). The expanding outer cylinder (4) is fixedly connected to the side of the expanding inner cylinder (5) away from the connecting member (3). The expanding inner cylinder (5) is fixedly connected to an inner support body (6) that is distributed in a ring and contacts the inner tube (2). The side of the inner support body (6) away from the inner tube (2) passes through the expanding inner cylinder (5). It is provided with two sets of symmetrically distributed protrusions (601), each set of protrusions (601) includes several protrusions (601) distributed at equal intervals. The protrusions (601) are fixedly connected to the expansion outer cylinder (4) and are used to pull the expansion outer cylinder (4) to form a pit on its surface when the expansion outer cylinder (4) expands. The inner support body (6) and the expansion inner cylinder (5) together form a support cavity (602). The expansion inner cylinder (5) is provided with annularly distributed arc-shaped holes (502). The number of arc-shaped holes (502) is equal to the number of inner support bodies (6). The support cavity (602) is connected to the filling cavity (501) through adjacent arc-shaped holes (502).

2. The tissue dilation catheter with a fixed structure according to claim 1, characterized in that, The arc-shaped hole (502) is located on the side of the expanded inner cylinder (5) away from the connecting member (3).

3. A tissue dilation catheter with a fixed structure according to claim 2, characterized in that, The connecting piece (3), the expansion outer cylinder (4), and the expansion inner cylinder (5) are all made of hydrophilic material, which facilitates the compression of the gas present in the filling cavity (501) into the support cavity (602).

4. A tissue dilation catheter with a fixed structure according to claim 2, characterized in that, The connecting member (3) is provided with annularly distributed flow holes (301), which are used for blood flow.

5. A tissue dilation catheter with a fixed structure according to claim 4, characterized in that, The number of the flow holes (301) is equal to the number of the inner supports (6), and all the inner supports (6) and all the flow holes (301) are staggered.

6. A tissue dilation catheter with a fixed structure according to claim 4, characterized in that, The end of the inner tube (2) is fixedly connected to an installation cylinder (7), and the installation cylinder (7) is fixedly connected to a ring-shaped guide plate (8). The guide plate (8) is fixedly connected to the expansion outer cylinder (4), and the guide plate (8) is used to guide the expansion outer cylinder (4) to move in the blood vessel.

7. A tissue dilation catheter with a fixed structure according to claim 6, characterized in that, The guide piece (8) is made of elastic material. When the outer expansion cylinder (4) and the inner expansion cylinder (5) expand, the guide piece (8) is in a stretched state. When the outer expansion cylinder (4) and the inner expansion cylinder (5) close, the guide piece (8) is in a free state.

8. A tissue dilation catheter with a fixed structure according to claim 6, characterized in that, The number of the guide pieces (8) is equal to the number of the flow holes (301), and all the flow holes (301) are staggered with all the guide pieces (8).

9. A tissue dilation catheter with a fixed structure according to claim 6, characterized in that, The cross-section of the mounting cylinder (7) is arc-shaped on the side away from the expansion outer cylinder (4).

10. A tissue dilation catheter with a fixed structure according to claim 9, characterized in that, The outer side of the expansion outer cylinder (4), the inner side of the expansion inner cylinder (5), and the outer side of the inner support (6) are all coated with PTFE to inhibit platelet adhesion.

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