Expandable catheter and expandable catheter sheath

Abstract

The present invention provides an expandable catheter and an expandable catheter sheath, wherein the expandable catheter includes a body, a connecting portion and a reinforcing portion; the expandable catheter switches between a contracted state and an expanded state along the circumferential direction; the body has an opening along the circumferential direction, the opening is continuously arranged along the axial direction, and the opening and closing of the opening corresponds to the state conversion of the expandable catheter; the connecting portion is connected to both sides of the opening; the reinforcing portion is continuously arranged in the body along at least a part of the circumference of the body, and the reinforcing portion does not overlap in the circumferential direction of the body. With such a configuration, the radial reinforcement of the body by the circumferentially non-closed reinforcing portion can effectively enhance the anti-bending and anti-compression capabilities of the expandable catheter without affecting the expansion performance of the body, achieving compliant bending in all directions, reducing the risk of bending due to excessive blood vessel curvature, and improving surgical safety.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to an expandable catheter and an expandable catheter sheath. Background Art

[0002] Interventional therapy is a common treatment method that uses natural orifices or tiny incisions in the human body to introduce specific instruments into the diseased part of the human body for minimally invasive treatment. There are many types of diseases that can be treated with interventional therapy, almost including major diseases of all systems and organs in the body. Its advantages mainly lie in the fact that vascular minimally invasive treatments are less invasive, have faster recovery, and are more easily accepted by patients. With the development of interventional therapy technology, its application is becoming more and more widespread, such as transcatheter aortic valve replacement (TAVR). One form of transcatheter aortic valve replacement (TAVR) is to deliver an interventional catheter through the femoral artery, deliver the artificial heart valve prosthesis to the aortic valve area, open it, and complete the implantation of the artificial valve, thereby restoring valve function.

[0003] Before inserting the interventional catheter through the femoral artery, a vascular access must be established in advance using a catheter sheath. On the one hand, it provides a smooth access route for the catheter that transports the valve (hereinafter referred to as the delivery device) to directly reach the abdominal aorta, and on the other hand, it plays a role in hemostasis during the entire operation. The vascular access established by the catheter sheath can meet the requirements of the delivery device's entry and withdrawal, as well as the passage of other accessories such as balloons, guidewires, and pigtail catheters.

[0004] The size of the catheter sheath usually needs to be larger than the size of the delivery catheter, that is, the inner diameter of the catheter sheath needs to be larger than the maximum outer diameter of the delivery catheter. Therefore, when a larger delivery catheter is required, the patient's blood vessel size needs to be large enough. However, when some patients have more calcification points or injuries in their blood vessels, the large-sized catheter sheath is prone to peeling off the calcification points when establishing vascular access, causing surgical complications such as vascular dissection and vascular wall damage, greatly increasing the risk during the operation. In practice, it has also been found that the existing catheter sheaths are not fully suitable for patients with smaller femoral artery vessels to perform transfemoral TAVR surgery, and the larger size of the catheter sheath also increases the risks associated with TAVR surgery. Based on the above problems, there is an urgent need to develop an expandable catheter sheath with a wider range of applicability.

[0005] However, the existing expandable catheter sheaths, on the one hand, are provided with a longitudinal gap, and the overlapping outer contour portions form a significantly increased outer diameter, and after being unfolded, a protruding edge is formed along the longitudinal direction of the outer contour, which poses a potential risk of causing vascular damage; on the other hand, the existing expandable catheter sheaths are very easy to bend along the folding direction. The femoral arteries of some patients are very tortuous, and there is a risk of the catheter sheath bending due to the excessive curvature of the blood vessel after entering. If bending occurs, it will lead to severe consequences such as vascular dissection and injury to the patient. Summary of the invention

[0006] The object of the present invention is to provide an expandable catheter and an expandable catheter sheath to solve the problem that the existing expandable catheter sheath is prone to cause blood vessel damage or bending.

[0007] In order to solve the above technical problems, the present invention provides an expandable catheter, which includes: a body, a connecting portion and a reinforcing portion;

[0008] The expandable catheter switches between a contracted state and an expanded state along the circumferential direction;

[0009] The body has openings along the circumferential direction, the openings are continuously arranged along the axial direction, and the openings are opened and closed corresponding to the state conversion of the expandable catheter; the connecting part is connected to both sides of the opening;

[0010] The reinforcement portion is continuously disposed in the body along at least a portion of the circumference of the body, and the reinforcement portion does not overlap in the circumferential direction of the body.

[0011] Optionally, in the expandable catheter, an extension length of the reinforcement portion along the circumferential direction of the body is not less than 3 / 4 of the inner circumference of the expandable catheter when it is in the contracted state.

[0012] Optionally, in the expandable catheter, the reinforcement portion includes a metal ring or a metal fold line; the length of the metal ring along the circumferential direction of the body is greater than the length along the axial direction of the body; the extension length of the metal fold line along the circumferential direction of the body is greater than the folding length along the axial direction of the body.

[0013] Optionally, in the expandable catheter, the reinforcement portion includes a plurality of metal rings, and the plurality of metal rings are arranged along the axial direction of the body.

[0014] Optionally, in the expandable catheter, a plurality of the metal rings are arranged at intervals, adjacent to each other in sequence, or overlapping each other in sequence.

[0015] Optionally, in the expandable catheter, a plurality of the metal rings are arranged at intervals with the same interval distance, or the interval distance gradually increases from the proximal end to the distal end along the axial direction of the body.

[0016] Optionally, in the expandable catheter, the lengths of the plurality of metal rings along the circumferential direction of the body are the same, or gradually decrease from the proximal end to the distal end along the axial direction of the body, and the plurality of metal rings are arranged parallel to each other or at an angle.

[0017] Optionally, in the expandable catheter, the expanded shape of the metal fold line is U-shaped, V-shaped, S-shaped, Z-shaped or bow-shaped.

[0018] Optionally, in the expandable catheter, the reinforcement portion further includes a reinforcement rib arranged along the axial direction of the body, the reinforcement rib sequentially passes through a plurality of the metal rings or the metal fold lines, and the reinforcement rib is located at the center of the metal ring or the metal fold line along the circumferential direction of the body.

[0019] Optionally, in the expandable catheter, when the expandable catheter is in the contracted state, the main body has an overlapping area along the circumferential direction, the opening is located in the overlapping area, and the connecting portion is clamped in the overlapping area; or, when the expandable catheter is in the contracted state, the main body does not overlap along the circumferential direction, and the connecting portion is stacked and covers the outside of the opening.

[0020] Optionally, the expandable catheter further comprises: an outer jacket layer and / or an inner lining layer;

[0021] The outer jacket layer is coated on the outer surface of the body and can adapt to the state conversion of the expandable catheter by elastic expansion and contraction;

[0022] The lining layer is attached to the inner surfaces of the body and the reinforcement part.

[0023] To solve the above technical problems, the present invention also provides an expandable catheter sheath, which includes the expandable catheter, sheath seat and dilator as described above, wherein the sheath seat is arranged at the proximal end of the expandable catheter, and the dilator is used to insert the expandable catheter from the proximal end of the sheath seat.

[0024] In summary, in the expandable catheter and expandable catheter sheath provided by the present invention, the expandable catheter includes a body, a connecting portion and a reinforcing portion; the expandable catheter switches between a contracted state and an expanded state along the circumferential direction; the body has an opening along the circumferential direction, the opening is continuously arranged along the axial direction, and the opening and closing of the opening corresponds to the state conversion of the expandable catheter; the connecting portion is connected to both sides of the opening; the reinforcing portion is continuously arranged in the body along at least a part of the circumferential direction of the body, and the reinforcing portion does not overlap in the circumferential direction of the body. In this configuration, the radial reinforcement of the body by the circumferentially non-closed reinforcing portion can effectively enhance the anti-bending and anti-compression capabilities of the expandable catheter, and does not affect the expansion performance of the body, realizes compliant bending in all directions, reduces the risk of bending due to excessive blood vessel curvature, and improves surgical safety. Further, the expandable catheter also includes a sheath layer coated outside the body and the reinforcing portion, and the setting of the sheath layer makes the outer surface of the expandable catheter smoother in any state, reducing damage to the blood vessel wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0026] Figure 1 is a schematic diagram of an expandable catheter sheath provided by a preferred embodiment of the present invention;

[0027] Figure 2 is a schematic diagram of a dilator provided by a preferred embodiment of the present invention;

[0028] Figure 3a yes Figure 1 A cross-sectional view of section AA of the expandable catheter sheath shown;

[0029] Figure 3b yes Figure 1 A cross-sectional view of the BB section of the expandable catheter sheath shown;

[0030] Figure 4 is a cross-sectional view of an expandable catheter provided by a preferred embodiment of the present invention;

[0031] Figure 5a is a stereoscopic view of an expandable catheter provided by a preferred embodiment of the present invention, wherein the reinforcement portion includes a metal ring;

[0032] Figure 5b is a stereoscopic view of an expandable catheter provided by a preferred embodiment of the present invention, wherein the reinforcement portion includes a metal fold line;

[0033] Figure 6a to Figure 6i are expanded views A to I of a reinforcement portion provided by a preferred embodiment of the present invention;

[0034] Figure 7a is a cross-sectional view of an expandable catheter provided by a preferred embodiment of the present invention, wherein the body has an overlapping area along the circumferential direction;

[0035] Figure 7b is a cross-sectional view of an expandable catheter provided by a preferred embodiment of the present invention, wherein the body does not overlap in the circumferential direction.

[0036] In the attached figure:

[0037] 1- expandable catheter; 2- sheath seat; 3- dilator; 11- head end portion; 12- dilation portion;

[0038] 51-main body; 510-opening; 52-connecting part; 53-reinforcement part; 531-extension section; 532-folded section; 533-reinforcement rib; 54-outer layer; 55-inner lining layer. DETAILED DESCRIPTION

[0039] In order to make the purpose, advantages and features of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing is different, and sometimes different scales are used.

[0040] As used in this specification, the singular forms "a", "an" and "the" include plural objects, the term "or" is generally used in the sense of including "and / or", the term "proximal end" is generally the end close to the operator, the term "distal end" is generally the end close to the patient close to the lesion, "one end" and "the other end" as well as "proximal end" and "distal end" generally refer to two corresponding parts, which include not only the endpoints, unless the content clearly indicates otherwise.

[0041] The core idea of ​​the present invention is to provide an expandable catheter and an expandable catheter sheath to solve the problems of the existing expandable catheter sheaths, such as easy to cause blood vessel damage or easy bending.

[0042] The expandable catheter comprises: a body, a connecting portion and a reinforcing portion; the expandable catheter switches between a contracted state and an expanded state along the circumferential direction; the body has an opening along the circumferential direction, the opening is continuously arranged along the axial direction, and the opening and closing of the opening corresponds to the state conversion of the expandable catheter; the connecting portion is connected to both sides of the opening; the reinforcing portion is continuously arranged in the body along at least a part of the circumference of the body, and the reinforcing portion does not overlap in the circumferential direction of the body. With such a configuration, the radial reinforcement of the body by the circumferentially non-closed reinforcing portion can effectively enhance the anti-bending and anti-compression capabilities of the expandable catheter without affecting the expansion performance of the body, achieving compliant bending in all directions, reducing the risk of bending due to excessive blood vessel curvature, and improving surgical safety. Furthermore, the expandable catheter also includes an outer layer and / or an inner lining layer coated on the outer surface of the body. The outer layer makes the outer surface of the expandable catheter smoother in any state, reducing damage to the blood vessel wall. The inner lining layer provides the expandable catheter with a smooth inner wall to further reduce the friction coefficient of the inner wall, which is more conducive to the insertion and passage of the catheter assembly of the dilator or delivery system.

[0043] The following description is given with reference to the accompanying drawings.

[0044] Please refer to Figures 1 to 7b ,in, Figure 1 is a schematic diagram of an expandable catheter sheath provided by a preferred embodiment of the present invention, Figure 2 is a schematic diagram of a dilator provided by a preferred embodiment of the present invention, Figure 3a yes Figure 1 A cross-sectional view of the AA section of the expandable catheter sheath shown, Figure 3b yes Figure 1 A cross-sectional view of the BB section of the expandable catheter sheath shown, Figure 4 is a cross-sectional view of an expandable catheter provided by a preferred embodiment of the present invention, Figure 5a is a stereoscopic view of an expandable catheter provided by a preferred embodiment of the present invention, wherein the reinforcement portion includes a metal ring, Figure 5b is a stereoscopic view of an expandable catheter provided by a preferred embodiment of the present invention, wherein the reinforcement portion includes a metal fold line, Figure 6a to Figure 6i are the expanded views A to I of the reinforcement part provided by a preferred embodiment of the present invention, Figure 7a is a cross-sectional view of an expandable catheter provided by a preferred embodiment of the present invention, wherein the body has an overlapping area along the circumferential direction, Figure 7b is a cross-sectional view of an expandable catheter provided by a preferred embodiment of the present invention, wherein the body does not overlap in the circumferential direction.

[0045] like Figure 1 and Figure 2 As shown, the first embodiment of the present invention provides an expandable catheter sheath, which includes: an expandable catheter 1, a sheath seat 2 and a dilator 3. The proximal end of the expandable catheter 1 is connected to the sheath seat 2, and the distal end is used to insert into the opening end of a predetermined blood vessel. The sheath seat 2 is arranged at the proximal end of the expandable catheter 1, and serves as a grip when the expandable catheter is pushed into the body. There is a sealing valve in the sheath seat 2 to ensure that as little blood is lost as possible during the entire operation of the expandable catheter. The sheath seat 2 is also connected to an emptying tube and a three-way stopcock, which can be used to flush and empty the expandable catheter. The three-way stopcock can be used for blood sampling, pressure testing, injection of drugs or contrast agents, etc. during surgery. The dilator 3 is used to insert the expandable catheter 1 from the proximal end of the sheath seat 2 to expand the blood vessel. When expanding the blood vessel, most of the dilator 3 is located in the main cavity of the expandable catheter 1 and extends from the distal end of the expandable catheter 1. The dilator 3 has a smooth transition at the head end. The dilator 3 can be passed through by a conventional medical guide wire, such as a 0.035" (0.035 inch) medical guide wire. The dilating catheter 1 is divided into two parts from the distal end to the proximal end, namely, a head end part 11 (whose cross section is as shown in FIG. Figure 3a ) and the expansion portion 12 (whose cross section is as shown Figure 3bAs shown). The head end portion 11 is conical, and the outer diameter gradually decreases toward the distal end with a smooth transition. The head end portion 11 can be provided with a developing mark for orientation and positioning under x-rays. Those skilled in the art can set the structure of the head end portion 11 according to the prior art. The expansion portion 12 has at least two states along the circumferential direction, a contracted state and an expanded state, and switches between the contracted state and the expanded state. The contracted state is actually a predetermined state, and the expanded state is actually a forced expansion state, wherein the predetermined state is the initial state of the expansion portion 12 in the natural state; the expanded state is the state of the expansion portion 12 when it is expanded by the expander 3 or when the implant enters the body through the expander 3.

[0046] Please refer to Figure 4 The expansion part 12 includes: a body 51, a connection part 52 and a reinforcement part 53; the body 51 has an opening 510 along the circumferential direction, and the opening is continuously arranged along the axial direction, and the opening and closing of the opening 510 corresponds to the state conversion of the expandable catheter 1 (expansion part 12); the connection part 52 is connected to both sides of the opening 510 of the body 51, connecting the two sides of the opening 510 together; the reinforcement part 53 is continuously arranged in the body 51 along at least a part of the circumference of the body 51, and the reinforcement part 53 does not overlap in the circumferential direction of the body 51. It should be understood that the opening 510 here extends along the axial direction of the body 51, and the body 51 is configured to have a certain elasticity. When the body 51 is subjected to a radially outward expansion force, the existence of the opening 510 allows the body 51 to expand radially outward. The connection part 52 is connected to both sides of the opening 510 to ensure that the outer periphery of the expandable catheter 1 is closed. It should be understood that the reinforcement part 53 is arranged in the body 51. In some embodiments, the reinforcement part 53 is attached to the inner wall of the body 51, or the inner wall of the body 51 is provided with a recessed area that matches the thickness of the reinforcement part 53, and the reinforcement part 53 is arranged in the recessed area; in other embodiments, the reinforcement part 53 is embedded in the side wall of the body 51, that is, the reinforcement part 53 is buried in the side wall of the body 51. The arrangement of the reinforcement part 53 can achieve radial reinforcement of the body 51, can effectively enhance the anti-bending and anti-compression capabilities of the expandable catheter, and does not affect the expansion performance of the body 51, and achieves compliant bending in all directions, reduces the risk of bending the expandable catheter due to excessive blood vessel curvature, and improves surgical safety.

[0047] Please refer to Figure 7aIn an exemplary embodiment, the body 51 includes a polymer tube layer with a rolled wall folding structure, which can use conventional medical polymer tubes such as Pebax series. The polymer tube layer is not closed in the circumference. Preferably, when the body 51 and the expandable catheter are in the contracted state, there is an overlapping area along the circumference, the opening 510 is located in the overlapping area, and the connecting portion 52 is clamped in the overlapping area. The overlapping area can be partially and fully expanded in the patient's blood vessel, and its expansion degree is determined by the size of the conveyor passing through. The advantages of setting the overlapping area are: on the one hand, the diameter of the expansion part 12 in the predetermined state is reduced, and on the other hand, the overlapping area is a part of the expansion part 12 in the expanded state, which can further improve the anti-bending performance of the expandable catheter 1 after expansion. In some other embodiments, the two edges of the polymer tube layer in the axial direction gradually become thinner toward the edge (both sides of the opening 510), which has the advantage of reducing the thickness of the overlapping area and making a smooth transition at the opening 510, which is conducive to the expansion of the connecting portion 52 and is more conducive to forming an expanded state. Please refer to Figure 7b In other embodiments, the body 51 does not overlap in the circumferential direction when the expandable catheter is in the contracted state, and the connecting portion 52 is stacked and covered outside the opening 510 to form a pleat-like shape. The body 51 does not overlap in the circumferential direction, that is, there is no overlapping area, and the opening 510 is directly covered by the connecting portion 52. The connecting portion 52 is preferably made of an elastic material to meet the expansion requirements of the expandable catheter 1. Preferably, the connecting portion 52 is made of a highly elastic and high-strength material, such as PTFE (polytetrafluoroethylene), FEP (fluorinated ethylene propylene copolymer), HDPE (high-density polyethylene), etc. In other embodiments, other materials with similar properties known to those skilled in the art can also be selected. More preferably, the connecting portion 52 is configured to be flattened but not stretched, so that it can better return to its original state after being expanded, thereby not causing plastic deformation.

[0048] Preferably, the extension length of the reinforcement portion 53 along the circumferential direction of the body 51 is not less than 3 / 4 of the inner circumference of the expandable catheter when it is in the contracted state. Figure 4 The inner circumference of the expandable catheter in the contracted state means that if the body 51 has a circumferential overlap area, the inner circumference does not include the body 51 section overlapped by the overlap area, but only covers the body 51 with a circumferential angle of 360°. Figure 4In the schematic body 51, the inner opening of the body 51 in the overlap area extends counterclockwise around the inner wall of the body 51 to the position corresponding to the inner opening of the body 51 and the overlap area, and does not continue to extend to the overlap area. The extension length of the reinforcement part 53 is not less than 3 / 4 of the inner circumference. It can be understood that one or both ends of the reinforcement part 53 can extend into the overlap area. Depending on the length of the overlap area, both ends of the reinforcement part 53 can also be located outside the overlap area. If the body 51 does not overlap circumferentially, such as Figure 7b As shown, the inner circumference of the expandable catheter in the contracted state refers to the circumference of the entire inner wall of the body 51. It should be understood that in some special cases, such as when the expandable catheter is in the contracted state, the body 51 is not circumferentially closed at the opening 510, and the circumferential coverage angle of the inner circumference is less than 360°, that is, it only matches the inner wall of the body 51. The reinforcement part 53 preferably includes a metal layer, which has good elasticity. The ratio of the extension length of the reinforcement part 53 to the inner circumference is between 3 / 4 and 1, so that the reinforcement part 53 is C-shaped in the circumferential direction, which increases the overall rigidity of the expandable catheter 1 and helps the expandable catheter 1 to automatically restore to the contracted state, that is, to the original open state after the external force is removed.

[0049] like Figure 5a As shown, in an exemplary embodiment, the reinforcing portion 53 includes a metal ring, and the length of the metal ring along the circumferential direction of the body 51 is greater than the length along the axial direction of the body 51, that is, when a single metal ring is unfolded, it is a circumferential rectangle, and the long side is perpendicular to the axis of the body. In the present invention, it is not limited to a rectangle with a long side perpendicular to the axis of the body, and it can also be a rectangle, square or ellipse with a long side parallel to the axis of the body. Preferably, the reinforcing portion 53 includes a plurality of metal rings, and the plurality of metal rings are arranged along the axial direction of the body 51. The setting of the metal ring provides a highly flexible anti-bending range, thereby realizing the compliant bending of the expandable catheter 1 in all directions.

[0050] Please refer to Figure 6a to Figure 6e , which respectively illustrate the expanded views A to E of the reinforcement portion 53.

[0051] Figure 6a Figure 5 is an expanded view A of the reinforcement portion 53, which illustrates a diamond-shaped metal ring, wherein a plurality of the metal rings are arranged at intervals, each metal ring has the same size and shape, the spacing between the metal rings is the same, and the plurality of metal rings are arranged parallel to each other. The design of the metal rings arranged independently at intervals can make the circumferential force of the expandable catheter 1 more uniform during expansion, and the shape recovery is better. The spacing between two axially adjacent metal rings can also be different to achieve different anti-bending properties, and a denser distribution can also effectively achieve axial compression resistance. Those skilled in the art can set the spacing between the metal rings according to actual conditions.

[0052] Figure 6b FIG. 1 is an expanded view B of the reinforcing portion 53, which illustrates an oblong metal ring, wherein a plurality of the metal rings are arranged at intervals, each metal ring has the same size and shape, the intervals between the metal rings are the same, and the plurality of metal rings are arranged parallel to each other. It is understandable that those skilled in the art can also set the metal ring to other shapes, such as a ring, a quadrilateral or an ellipse, etc., and the shape of each metal ring can be the same or different.

[0053] Figure 6c The expanded view C of the reinforcement part 53 shows an oblong metal ring, wherein a plurality of the metal rings are arranged at intervals, each metal ring has the same size and shape, the intervals between the metal rings are the same, and the plurality of the metal rings are arranged at an angle. It should be understood that the angled arrangement here can be a group of two arranged in an "eight" shape as shown in the figure, or a group of three arranged in a "chuan" shape, or more groups arranged repeatedly, and each metal ring can also be arranged at an irregular angle. The metal rings arranged at an angle can provide a certain support force to the axial direction when the expandable catheter 1 is expanded, thereby improving its anti-bending performance.

[0054] Figure 6d It is an expanded view D of the reinforcement portion 53 , which illustrates an oblong metal ring. A plurality of the metal rings are arranged at intervals, and the lengths of the plurality of metal rings along the circumferential direction of the main body 51 gradually decrease from the proximal end to the distal end along the axial direction of the main body 51 . Figure 6d The left side is the proximal end, and the right side is the distal end. The metal ring at the proximal end has a longer circumferential length along the body 51, and is relatively close to the sheath seat 2, while the metal ring at the distal end has a shorter circumferential length along the body 51, and is relatively far away from the sheath seat 2. With such an arrangement, in practice, the expandable catheter 1 can be expanded to different degrees according to different expansion requirements of the distal and proximal ends. In the initial stage of expansion, the radial expansion force is smaller, and the longer metal ring can better maintain a small deformation, thereby improving stability during expansion and facilitating operation. In some other examples, the spacing distance between the metal rings gradually increases from the proximal end to the distal end along the axial direction of the body 51. That is, the metal rings close to the sheath seat 2 are densely distributed, and the metal rings far away from the sheath seat 2 are sparsely distributed. In this way, the expandable catheter 1 can also be expanded to different degrees according to different expansion requirements of the distal and proximal ends.

[0055] Figure 6eThe expanded view E of the reinforcement part 53 illustrates a diamond-shaped metal ring, wherein a plurality of the metal rings are arranged adjacent to each other in sequence, each metal ring is of the same size and shape, and the plurality of metal rings are arranged parallel to each other. Adjacent metal rings are connected to each other to form a pattern similar to a woven mesh. The advantage of such a setting is that the continuous metal rings provide better compression resistance and enhance the torsion control. Compared with the design of the spaced metal rings, the metal rings arranged adjacent to each other in sequence play a stronger supporting role, effectively improving the compression resistance of the expandable catheter 1 and enhancing the torsion control performance of the expandable catheter 1. Of course, in some other examples, those skilled in the art can also configure the plurality of metal rings to be arranged in sequence in an overlapping manner, that is, the metal rings have overlapping parts to form a grid shape, which can further improve the supporting performance of the metal rings.

[0056] like Figure 5b As shown, in an exemplary embodiment, the reinforcement portion 53 includes a metal fold line, and the extension length of the metal fold line along the circumferential direction of the main body 51 is greater than the folding length along the axial direction of the main body 51. The provision of the metal fold line can further improve the bending resistance of the expandable catheter 1, and the folding structure can achieve better compression resistance. Preferably, the metal fold line can be woven from a single metal wire, or it can be formed by connecting the metal fold line by bonding, welding, etc. after being manufactured separately. The metal fold line can be designed with U-shaped, V-shaped, S-shaped, Z-shaped or bow-shaped weaving. Generally, the metal fold line includes an extension section 531 and a folding section 532, the extension section 531 extends along the circumferential direction of the main body 51, and the folding section 532 extends along the axial direction of the main body 51. The metal fold line connects the circumferentially arranged extension sections 531 through the fold section 532, thereby improving the axial compression resistance of the expandable catheter 1 and also improving the bending resistance, thereby ensuring that the overall shape of the expandable catheter 1 remains stable while being expanded.

[0057] Please refer to Figure 6f~Figure 6h , which respectively illustrate the expanded views F to H of the reinforcement portion 53.

[0058] Figure 6f FIG. 5 is an expanded view F of the reinforcement portion 53, which illustrates a metal fold line with a U-shaped expanded shape, wherein each extension section 531 and fold section 532 have the same length and shape, thereby enabling the expandable catheter 1 to be more uniformly stressed in the circumferential direction during expansion and to recover its shape better. Different lengths of the fold section 532 can achieve different anti-bending properties, and a shorter fold section 532 can also effectively achieve axial compression resistance. A person skilled in the art can set the length of the fold section 532 according to actual conditions.

[0059] Figure 6gFIG. 1 is an expanded view G of the reinforcing portion 53 , which illustrates a metal fold line having a V-shaped expanded shape, wherein each of the extending section 531 and the folded section 532 has the same length and shape.

[0060] Figure 6h FIG. 1 is an expanded view H of the reinforcing portion 53, which illustrates a metal fold line with an expanded shape of an arch, and the length and shape of each extension segment 531 and folded segment 532 are the same. It can be understood that those skilled in the art can also adjust the length and shape of the extension segment 531 and the folded segment 532 according to the requirements of the expandable catheter 1 for different degrees of expansion according to different expansion requirements of the distal end and the proximal end, for example, the extension segment 531 close to the sheath seat 2 is longer, and the extension segment 531 away from the sheath seat 2 is shorter; or the folded segment 532 close to the sheath seat 2 is shorter, and the folded segment 532 away from the sheath seat 2 is longer, etc.

[0061] In some other embodiments, the reinforcing portion 53 further includes a reinforcing rib 533 arranged along the axial direction of the body 51, and the reinforcing rib 533 sequentially passes through a plurality of the metal rings or the metal return lines. Optionally, there may be at least one reinforcing rib 533, and preferably, the reinforcing rib 533 is located at the center of the metal ring or the metal return line along the circumferential direction of the body 51. Please refer to Figure 6i , which is an expanded view I of the reinforcement part 53, and the reinforcement part 53 includes a plurality of metal rings arranged at equal intervals. Preferably, the reinforcing ribs 533 are arranged in the inner layer of the metal ring, located at the central axis of the metal ring structure, and such an arrangement effectively enhances the axial compression resistance and torsional deformation resistance of the expandable catheter 1. The reinforcing ribs 533 effectively bear the axial pressure of the expandable catheter 1, so that the metal ring can fully perform radial expansion and recovery functions. At the same time, the expandable catheter 1 with the reinforcing ribs 533 has a significantly improved overall anti-bending performance. It should be noted that those skilled in the art can set the number of reinforcing ribs 533 according to the actual situation, and can also add reinforcing ribs 533 to the metal fold line, which also has a good effect. Preferably, the material of the metal ring, the metal fold line or the reinforcing rib 533 can be selected from memory alloy materials to improve the pre-forming ability and the recovery ability after expansion of the reinforcing part 53.

[0062] Preferably, the expandable catheter further comprises: an outer layer 54 and / or an inner lining layer 55; the outer layer 54 covers the outer surface of the body 51 and can adapt to the expansion and contraction of the expandable catheter 1 by elastic expansion and contraction; the inner lining layer 55 is attached to the inner surface of the body 51 and the reinforcement part 53. Figure 4In one embodiment, the expandable catheter 1 is mainly divided into four layers from the outside to the inside, namely, the outer layer 54, the body 51, the reinforcement part 53 and the inner lining layer 55. It should be understood that in some embodiments, the outer layer 54 and the inner lining layer 55 can be provided at the same time, while in other embodiments, only one of the outer layer 54 and the inner lining layer 55 can be provided.

[0063] The outer jacket layer 54 uses a material with higher elasticity than the body 51 to cover the entire circumference, and its two ends are bonded to the tube wall of the body 51 to form the outer surface of the expandable catheter 1. The material of the outer jacket layer 54 can be selected from TPU material (thermoplastic polyurethane) or Pebax material (polyether block polyamide), etc., which has a high elongation at break, can be radially stretched when the body 51 expands, and recover when the body 51 contracts, that is, the outer jacket layer 54 can adapt to the expansion and contraction of the body 51. Preferably, the outer jacket layer 54 is partially fixedly connected to the body 51 in the circumferential direction, and the connection method is not limited, and conventional preparation processes such as adhesion can be selected.

[0064] The inner lining 55 provides a smooth inner wall to form the inner surface of the expandable catheter 1. In some embodiments, the reinforcement portion 53 is attached to the inner wall of the body 51, and in the area of ​​the body 51 where the reinforcement portion 53 is not provided, the inner lining 55 is attached to the inner wall of the body 51, and in the area where the reinforcement portion 53 is provided, the inner lining 55 is attached to the inner wall of the reinforcement portion 53. Optionally, the inner lining 55 can also be attached to the inner wall of the connecting portion 52 to cover the inner surface of the expandable catheter 1, so that the inner lining 55 is arranged on the inner surface of the expandable catheter 1 in a circumferentially closed manner. Preferably, the inner lining 55 uses a material with high strength and low friction coefficient, such as PTFE (polytetrafluoroethylene), FEP (fluorinated ethylene propylene copolymer), HDPE (high-density polyethylene), etc., to further reduce the friction coefficient of the inner wall, which is more conducive to the insertion and passage of the dilator 3 or the catheter component of the delivery system. In particular, in some embodiments, the connection portion 52 may be formed by extending the lining layer 55, that is, the material and structure of the connection portion 52 are the same as those of the lining layer 55. Optionally, the lining layer 55 is fixedly connected to the inner wall of the body 51 or the inner wall of the reinforcement portion 53, and the connection method is not limited, and conventional preparation processes such as adhesion can be selected.

[0065] The following schematically illustrates the use of the expandable catheter sheath provided in this embodiment.

[0066] First, use the expandable catheter sheath to establish a vascular access in TAVR surgery: first use a syringe filled with saline to connect to the three-way stopcock of the sheath seat 2 to empty the expandable catheter 1, and then empty the dilator 3. Insert the dilator 3 into the expandable catheter 1 along the sheath seat 2 to ensure that the dilator 3 and the expandable catheter 1 are tightly matched. Insert the expandable catheter 1 as a whole into the patient's blood vessel along the guide wire that has been inserted into the body in advance.

[0067] Then, the sheath holder 2 is held to fix the expandable catheter 1 and the dilator 3 is withdrawn, followed by the insertion of the conveyor, which reaches the expandable catheter 1 portion through the sheath holder 2. When the conveyor is inserted, the expandable catheter 1 is expanded. The body 51 is opened to the extent that the conveyor catheter can pass according to the size of the conveyor catheter, and the outer jacket layer 54 is radially expanded in a compliant manner to maintain the uniformity of the outer surface of the expandable catheter 1. At the same time, the opening 510 is expanded, and the reinforcement portion 53 is synchronously expanded. After the conveyor is withdrawn, the body 51 and the reinforcement portion 53 automatically return to the initial shape, and preferably the connecting portion 52 also returns to the initial shape.

[0068] In the process of inserting the catheter of the conveyor into the expandable catheter 1, the overlapping area of ​​the main body 51 is expanded, the reinforcement part 53 is expanded, the connecting part 52 is expanded, the opening 510 is enlarged, and the lining layer 55 expands with the expansion of the main body 51; at the same time, the outer jacket layer 54 also expands synchronously, and it can still accommodate the expansion of all internal materials, and finally the connecting part 52 is flattened but not stretched.

[0069] In summary, in the expandable catheter and expandable catheter sheath provided by the present invention, the support force of the expandable catheter 1 is increased on the basis of maintaining the expandability of the expandable catheter 1 unchanged, the anti-bending and anti-compression capabilities are improved, and the flexibility is increased while the anti-bending capabilities are increased. The combination of the reinforcement part 53 and the main body 51 provides an expandable catheter 1 with high support force and good bending performance, which has a smaller outer diameter, is conducive to passing through thinner blood vessels, avoids peeling calcification points, damages blood vessel walls, and reduces surgical risks; a variety of outer diameter size conveyors can be adapted within the expandable range of the expandable catheter 1, and is suitable for more patients. In addition, the combination of the reinforcement part 53 and the main body 51 enhances the support force and anti-bending capabilities while achieving its expandability and recoverability, thereby making it easier to operate when establishing a vascular access and better adapting to curved vascular paths. Furthermore, the outer jacket layer 54 provides the expandable catheter with a more uniform and smooth outer surface, which helps reduce the risk of damaging the blood vessel. The inner lining layer 55 provides the expandable catheter with a smooth inner wall to further reduce the friction coefficient of the inner wall, which is more conducive to the insertion and passage of the catheter assembly of the dilator or delivery system.

[0070] It should be noted that the above description is only a description of the preferred embodiment of the present invention, and is not any limitation to the scope of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure are within the scope of protection of the claims.

Claims

1. An expandable catheter, characterized in that: include: Main body, connecting part and reinforcement part; The expandable catheter switches between a contracted state and an expanded state along the circumferential direction; The body has openings along the circumferential direction, the openings are continuously arranged along the axial direction, and the openings are opened and closed corresponding to the state conversion of the expandable catheter; the connecting part is connected to both sides of the opening; The reinforcement portion is continuously disposed in the body along at least a portion of the circumference of the body, and the reinforcement portion does not overlap in the circumferential direction of the body; The reinforcement portion includes a metal ring or a metal return line, and the reinforcement portion also includes a reinforcement rib arranged along the axial direction of the body, and the reinforcement rib sequentially passes through a plurality of the metal rings or the metal return lines; An extension length of the reinforcement portion along the circumferential direction of the body is not less than 3 / 4 of the inner circumference of the expandable catheter when it is in the contracted state.

2. The expandable catheter according to claim 1, characterized in that The length of the metal ring along the circumferential direction of the body is greater than the length along the axial direction of the body; the extension length of the metal fold line along the circumferential direction of the body is greater than the folding length along the axial direction of the body.

3. The expandable catheter according to claim 2, characterized in that The reinforcement portion includes a plurality of metal rings, and the plurality of metal rings are arranged along the axial direction of the body.

4. The expandable catheter according to claim 3, characterized in that The plurality of metal rings are arranged at intervals, adjacent to each other, or overlapped with each other.

5. The expandable catheter according to claim 4, characterized in that The plurality of metal rings are arranged at intervals and have the same interval distance, or the interval distance increases gradually from the proximal end to the distal end along the axial direction of the body.

6. The expandable catheter according to claim 3, characterized in that The lengths of the plurality of metal rings along the circumferential direction of the body are the same, or gradually decrease from the proximal end to the distal end along the axial direction of the body, and the plurality of metal rings are arranged parallel to each other or at an angle.

7. The expandable catheter according to claim 1, characterized in that The reinforcing rib is located at the center of the metal ring or the metal fold line along the circumferential direction of the main body.

8. The expandable catheter according to claim 1, wherein: When the expandable catheter is in the contracted state, the main body has an overlapping area along the circumferential direction, the opening is located in the overlapping area, and the connecting portion is clamped in the overlapping area; alternatively, when the expandable catheter is in the contracted state, the main body does not overlap along the circumferential direction, and the connecting portion is stacked and covers the outside of the opening.

9. The expandable catheter according to claim 1, characterized in that The expandable catheter further comprises: an outer jacket layer and / or an inner lining layer; The outer jacket layer is coated on the outer surface of the body and can be elastically expanded and contracted to adapt to the state conversion of the expandable catheter; The lining layer is attached to the inner surfaces of the body and the reinforcement part.

10. An expandable catheter sheath, characterized in that: It comprises an expandable catheter, a sheath seat and a dilator as described in any one of claims 1 to 9, wherein the sheath seat is arranged at the proximal end of the expandable catheter, and the dilator is used to insert the expandable catheter from the proximal end of the sheath seat.

Images