CN115645708A

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Info

Publication number: CN115645708A
Application number: CN202211296423.3A
Authority: CN
Inventors: 张勇; 赵馨莲; 詹航敏; 杨夏燕
Original assignee: Chengdu Newmai Biotechnology Co ltd
Current assignee: Chengdu Newmai Biotechnology Co ltd
Priority date: 2022-10-21
Filing date: 2022-10-21
Publication date: 2023-01-31

Abstract

The invention discloses an expandable catheter sheath and a using method thereof. The catheter component comprises an expansion pipe and an outer pipe sleeved on the expansion pipe. An expansion cavity is arranged in the expansion pipe, at least one branch pipe is communicated with the expansion cavity, and fluid flows into or out of the expansion cavity through the branch pipe. When fluid flows into the expansion cavity through the branch pipe, the expansion pipe expands and props open the outer pipe, so that the outer diameter of the catheter component is increased; when fluid flows out of the expansion cavity through the branch tube, the expansion tube and the outer tube contract, so that the outer diameter of the catheter component is reduced. The invention controls the expansion range of the catheter sheath by arranging the expansion tube with the expansion cavity and filling or extracting fluid into the expansion cavity, so that the catheter sheath can enter and exit a blood vessel with smaller diameter. Meanwhile, medical personnel can flexibly control the expansion degree of the expandable catheter sheath according to actual needs, and the application range is wide.

Description

Expandable catheter sheath and method of use

Technical Field

The invention relates to the technical field of medical instruments, in particular to an expandable catheter sheath and a using method thereof.

Background

At present, cardiovascular disease treatment technologies include drug therapy, surgical operation and interventional therapy, wherein cardiovascular interventional therapy is widely applied to clinic due to the advantages of small trauma, high safety, good treatment effect and the like. Cardiovascular intervention is a technique for diagnosis or treatment by entering into the heart cavity or blood vessel through a vascular puncture route.

Catheter sheaths are used to establish vascular access during cardiovascular interventional procedures to facilitate introduction of interventional therapeutic/diagnostic devices into a patient's blood vessel. In the prior art, the outer diameter of a common catheter sheath is generally fixed, so that the catheter sheath cannot cover all lower cavity blood vessel diameters of patients and aorta blood vessels with calcified blood vessel walls, particularly, the lower cavity blood vessels of the patients in Asian countries become narrow, blood vessel damage is likely to be caused, and the catheter sheath is not beneficial to suturing the blood vessels; and the aorta vessels of some old patients are calcified, and the calcified plates can fall off when a large-diameter catheter sheath is placed in the aorta vessels. In addition, the catheter sheath is an appliance which is firstly placed into a blood vessel and is finally withdrawn, the time in the blood vessel is long, if the blood vessel is expanded by a large diameter for a long time, vasospasm is easily caused, and the probability of operation complications is increased.

In this regard, some expandable sheaths have been developed and put into clinical use, however, in patent document CN206372159U, most expandable sheaths are expanded by external devices, and the expansion range is limited. Moreover, there is a possibility that the external device is stuck due to the fact that the external device cannot be sufficiently spread by the pressure of the blood vessel wall when penetrating into the sheath.

Therefore, how to improve the technical defects in the prior art is always a problem to be solved by those skilled in the art.

Disclosure of Invention

The invention aims to provide an expandable catheter sheath and a using method thereof, wherein the expandable catheter sheath can enter and exit a blood vessel with a smaller diameter, and medical staff can flexibly control the expansion degree of the expandable catheter sheath according to actual needs, so that the expandable catheter sheath has a wide application range.

The technical scheme provided by the invention is as follows:

an expandable catheter sheath, comprising:

the hemostatic valve is arranged at one end of the catheter component;

the catheter component comprises an expansion pipe and an outer pipe sleeved on the expansion pipe;

an expansion cavity is arranged in the expansion pipe, at least one branch pipe is communicated with the expansion cavity, and fluid flows into or out of the expansion cavity through the branch pipe;

when fluid flows through the branch tube into the expansion cavity, the expansion tube expands and struts the outer tube, so that the outer diameter of the catheter assembly is increased;

when fluid flows out of the expansion cavity through the branch tube, the expansion tube and the outer tube contract, so that the outer diameter of the catheter assembly is reduced.

In some embodiments, the wall of the expanding tube is a coiled wall structure and has overlapping parts;

when fluid flows into the expansion cavity through the branch pipe, the expansion pipe is expanded, and the overlapped parts of the pipe walls of the expansion pipe are reduced;

when fluid flows out of the expansion cavity through the branch pipes, the expansion pipe contracts, and the overlapped parts of the pipe walls of the expansion pipe are increased.

In some embodiments, the expanding tube is surrounded by a first channel for passing an external instrument, and the first channel is communicated with an emptying tube.

In some embodiments, the expansion tubes are arranged in a spiral along the central axis of the outer tube;

when fluid flows into the expansion cavity through the branch pipe, the expansion pipe is expanded, and the diameter and the thread pitch of a spiral line formed by the expansion pipe are increased;

when fluid flows out of the expansion cavity through the branch tube, the expansion tube contracts, and the diameter and the pitch of a spiral line formed by the expansion tube become smaller.

In some embodiments, the catheter assembly further comprises an inner tube;

a second channel is formed around the expansion pipe, the inner pipe penetrates through the second channel, one end of the inner pipe is arranged on the hemostasis valve, and the other end of the inner pipe is fixedly connected with the outer pipe;

and a third channel for external instruments to pass through is formed in the inner tube in an enclosing manner, and the third channel is communicated with an emptying tube.

In some embodiments, the catheter assembly further comprises a stress diffusion tube;

the stress diffusion pipe is sleeved on the outer pipe, one end of the stress diffusion pipe is arranged on the hemostasis valve, and the other end of the stress diffusion pipe is fixed on the outer side wall of the outer pipe and used for enhancing the connection strength of the outer pipe and the hemostasis valve.

In some embodiments, the dilation tube is made of a non-compliant material and the outer tube is made of a compliant material.

In some embodiments, the fluid flowing into or out of the expansion chamber through the branch tube is sterile saline containing a contrast agent.

In some embodiments, the branch pipe is provided with a valve, and the conduction or the blockage of the branch pipe is realized by controlling the opening and closing of the valve.

The present invention also provides a method of using an expandable catheter sheath,

the expandable catheter sheath comprises an expansion tube and an outer tube sleeved on the expansion tube, an expansion cavity is formed in the expansion tube, and at least one tube is communicated with the expansion cavity; and the expansion pipe is surrounded with a channel for external instruments to penetrate;

the expandable catheter sheath guides the fluid in the expansion cavity to the outside through the branch pipe, so that the size of the outer diameter of the outer pipe is at the minimum value, and the expandable catheter sheath is convenient to enter a delivery state;

the expandable sheath guides the external fluid into the expansion cavity through the branch tube, and the size of the outer diameter of the outer tube and the size of the passage are gradually increased to the required size, so that the expandable sheath is convenient to enter a use state which can be passed by an external instrument.

The invention has the technical effects that:

1. in the patent, an expansion tube with an expansion cavity is arranged, and fluid is filled or extracted into the expansion cavity to control the expansion range of the catheter sheath, so that the catheter sheath can enter and exit a blood vessel with a smaller diameter. Meanwhile, medical care personnel can flexibly control the expansion degree of the expandable catheter sheath according to actual needs, and the expandable catheter sheath is more beneficial to the in and out of external instruments and has wide application range.

2. In this patent, the expansion pipe is the spiral along outer tube central axis direction and distributes, so, when the expansion pipe inflation, the diameter and the pitch of the helix of its formation all can the grow, can strut the outer tube more evenly and completely. At the moment, the stress of the outer tube is more uniform, and the expansion effect on the blood vessel is good. In addition, in order to further improve the smoothness degree of the external apparatus penetrating into the catheter sheath, an inner tube is further arranged in the second channel formed by the enclosing of the expansion tubes distributed in a spiral manner in a penetrating manner, the external apparatus penetrates into the third channel formed by the enclosing of the inner tube, and the situation that the external apparatus is clamped by the expansion tubes distributed in a spiral manner can be effectively avoided.

3. In this patent, the expansion pipe is made of a non-compliant material, so that the outer diameter of the outer pipe can be expanded while providing a small radial supporting force to the outer pipe. Relatively, the outer tube adopts compliance material to make, so, can guarantee that the outer tube all keeps comparatively smooth surface before and after the expansion, effectively reduces the harm of pipe sheath to the blood vessel.

4. In this patent, expandable catheter sheath is before getting into the blood vessel, leads to the external world through the branch pipe with the fluid of expansion intracavity earlier, is for avoiding expanding intracavity and contain the air to make catheter sheath can not get into patient's blood vessel with minimum diameter, influence catheter sheath's performance.

Drawings

The invention is described in further detail below with reference to the following figures and embodiments:

FIG. 1 is a schematic view of an expandable catheter sheath provided in accordance with the present invention;

FIG. 2 is a schematic perspective view of an outer tube, an expansion tube and an inner tube according to the present invention;

FIG. 3 is a cross-sectional view of the outer tube, the expandable tube and the inner tube according to the present invention.

The reference numbers indicate:

110. expanding the tube; 111. an expansion lumen; 112. a second channel; 120. an outer tube; 130. a branch pipe; 140. An inner tube; 141. a third channel; 150. emptying the pipe; 160. a stress diffusion tube; 170. a valve;

200. a hemostatic valve.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will be made with reference to the accompanying drawings. It is obvious that the drawings in the following description are only some examples of the invention, and that for a person skilled in the art, without inventive effort, other drawings and embodiments can be derived from them.

For the sake of simplicity, only those parts relevant to the invention are schematically shown in the drawings, and they do not represent the actual structure as a product. In addition, in order to make the drawings concise and understandable, components having the same structure or function in some of the drawings are only schematically illustrated or only labeled. In this document, "one" means not only "only one" but also a case of "more than one".

It should be further understood that the term "and/or" as used in this specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items and includes such combinations.

In this context, it is to be understood that, unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in a specific case to those of ordinary skill in the art.

In the embodiments shown in the drawings, the directions such as up, down, left, right, front, and rear are used to explain the structure and movement of various components of the present invention not absolutely but relatively. These illustrations are appropriate when these components are in the positions shown in the figures. If the description of the positions of these components changes, the indication of these directions changes accordingly.

In addition, in the description of the present application, the terms "first", "second", and the like are used only for distinguishing the description, and are not intended to indicate or imply relative importance.

In accordance with one embodiment of the present invention, an expandable catheter sheath and method of use are provided, see fig. 1-3. The expandable sheath may include a catheter assembly and ahemostatic valve 200 disposed at one end of the catheter assembly. The catheter assembly may include anexpandable tube 110 and anouter tube 120 covering theexpandable tube 110, wherein anexpandable cavity 111 is formed in theexpandable tube 110, and at least onebranch tube 130 is connected to theexpandable cavity 111, such that fluid can flow into or out of theexpandable cavity 111 through thebranch tube 130. When fluid flows into theexpansion chamber 111 through thebranch tube 130, theexpansion tube 110 expands and expands theouter tube 120, causing the outer diameter of the catheter assembly to increase; when fluid flows out of theexpansion cavity 111 through thebranch tube 130, theexpansion tube 110 contracts, and the outer diameter of the catheter assembly is reduced because theouter tube 120 which is expanded due to the force is re-contracted.

It should be noted that, referring to fig. 2 and 3, the area enclosed by the dilatingtubes 110 is provided with a passage for external instruments to pass through, and when the dilatingtubes 110 are expanded, the passage is enlarged; when thedilation tube 110 is deflated, the passage is also deflated.

In this embodiment, the expandable sheath is configured to be introduced into and withdrawn from a blood vessel of a patient with a small diameter by providing anexpandable tube 110 having anexpandable lumen 111 and filling or withdrawing a fluid into or from theexpandable lumen 111 to control the expandable range of the sheath. Meanwhile, medical care personnel can flexibly control the expansion degree of the expandable catheter sheath according to actual needs, so that the expandable catheter sheath is more beneficial to the entering and exiting of external instruments, and the application range is wide.

It should be noted that the expansion limit of the catheter sheath provided in this embodiment depends on the ductility of theexpansion tube 110 and theouter tube 120, and can be flexibly set according to actual requirements during production and manufacturing, which is not described herein again and falls within the protection scope of the present invention.

In the prior art, a common expandable catheter sheath is expanded under stress after an external instrument enters the catheter sheath, so that the expansion range of the catheter sheath is limited to a certain extent. The catheter sheath provided by the embodiment can change the expansion degree of the catheter sheath by changing the volume of the filled fluid, and the application range is wide.

In addition, when medical personnel used the catheter sheath because of the external instrument entering expansion, because of the pressure that external instrument can receive the vascular wall, the speed of penetrating is comparatively slow, has the risk of blocking in addition. When the medical personnel use the catheter sheath provided by the embodiment, the channel which can be penetrated by the external apparatus in the catheter sheath can be expanded to a proper size, and then the external apparatus is directly penetrated, so that the penetration speed is high, the operation is simple, and the safety is high.

Specifically, referring to fig. 1, the number of thebranch pipes 130 in the present embodiment may be one, and when it is required to fill the fluid into theexpansion cavity 111, thebranch pipes 130 are used as a pipeline for filling the fluid into theexpansion cavity 111; when it is necessary to extract the fluid in theexpansion chamber 111, thebranch tube 130 serves as a conduit for extracting the fluid in theexpansion chamber 111.

Of course, the number of thebranch pipes 130 may be two, and in this case, one of thebranch pipes 130 may serve as a dedicated pipe for filling theexpansion chamber 111 with fluid, and theother branch pipe 130 may serve as a dedicated pipe for withdrawing fluid from theexpansion chamber 111.

In one embodiment, the wall of thedilation tube 110 is of a rolled wall construction and has overlapping portions. When the fluid flows into theexpansion cavity 111 through thebranch pipe 130, theexpansion pipe 110 is expanded, and the overlapping parts of the pipe walls of theexpansion pipe 110 are reduced; when the fluid flows out of theexpansion chamber 111 through thebranch pipes 130, theexpansion pipe 110 is contracted, and the portions of the pipe walls of theexpansion pipe 110 overlapping each other are increased.

At this time, a channel which is provided in the region surrounded by thedilation tube 110 and through which an external instrument can penetrate is a first channel surrounded by thedilation tube 110. In this way, when the medical staff fills the fluid into thedilating lumen 111, the overlapped portion of the vessel walls of the dilatingtube 110 is expanded and has a certain supporting force, so that the blood vessel of the patient is dilated together with theouter tube 120. Meanwhile, after the overlapped parts of the tube walls of the dilatingtubes 110 are unfolded, the cross-sectional area of the first channel formed by the surrounding arrangement of the dilating tubes is increased, so that external instruments can conveniently penetrate into the first channel.

Preferably, referring to fig. 1, the first channel is communicated with anevacuation tube 150 for exhausting air in the first channel, preventing air from entering into blood vessels, and further improving the safety of the operation.

In one embodiment, referring to fig. 2 and 3, thedilation tube 110 is helically disposed along the central axis of theouter tube 120. When the fluid flows into theexpansion chamber 111 through thebranch pipe 130, theexpansion pipe 110 is expanded, and the diameter and pitch of the spiral line formed by theexpansion pipe 110 become large; when the fluid flows out of theexpansion chamber 111 through thebranch tubes 130, theexpansion tube 110 contracts, and the diameter and pitch of the spiral line formed by theexpansion tube 110 become smaller.

When the dilatingtube 110 provided by the present embodiment is expanded, the diameter and pitch of the spiral line formed by the dilating tube will be increased, and the dilating tube has a certain supporting force, so that theouter tube 120 can be more uniformly and completely expanded. Meanwhile, theouter tube 120 is more uniformly stressed, and the expansion effect on the blood vessel is good.

Specifically, before the expansion of theexpansion pipe 110, the diameter of the spiral line formed by the expansion pipe is 4-8mm; after theexpansion tube 110 is expanded, the formed spiral has a diameter of 6-12mm.

To further enhance the supporting effect of the expandingtube 110 on theouter tube 120 in the above embodiment, in a preferred embodiment, at least one axial tube extending along the central axis of theouter tube 120 is disposed on the side of the expandingtube 110 facing theouter tube 120. Specifically, the number of the axial tubes may be two, three, four, etc., and the axial tubes are distributed at regular intervals to ensure that theouter tube 120 can receive a uniform supporting force, so that the catheter assembly has a better expansion effect, and is more favorable for the catheter sheath to expand the blood vessel of the patient.

In one embodiment, thedilation tube 110 may comprise at least two axial branches extending along a central axis of theouter tube 120, and a first annular branch communicating with an end of the axial branch distal from thehemostasis valve 200 and a second annular branch communicating with an end of the axial branch proximal to thehemostasis valve 200.

When fluid flows into theexpansion chamber 111 through thebranch tube 130, the axial branch tube, the first annular branch tube, and the second annular branch tube are expanded, thereby expanding theouter tube 120. At this time, the axial tube separation can provide enough supporting force to theouter tube 120, so that theouter tube 120 has enough force to prop open the blood vessel of the patient while theouter tube 120 is propped open. Specifically, the number of the axial branched tubes may be three, four, five, etc., and the axial branched tubes are uniformly spaced, so that the expandingtube 110 can more uniformly and completely expand theouter tube 120. Meanwhile, theouter tube 120 is more uniformly stressed, and the expansion effect on the blood vessel is good.

In contrast, as fluid exits theexpansion chamber 111 via thebranch tube 130, the axial branch, the first annular branch, and the second annular branch all contract.

In one embodiment, each of the axial branches is of a different length, such that thedilation tube 110 flexes to a different degree as fluid flows through thebranch 130 into thedilation lumen 111, allowing the sheath to accommodate a wider range of complex vessel configurations. Of course, in actual production, the specific length of each axial branch pipe should be flexibly set according to actual needs, and is not described herein.

Notably, the present implementation provides an adjustable-bend catheter sheath suitable for use with external devices to the cerebral vasculature of a patient. If the catheter sheath is adapted to use external instruments to the aorta or vein of a patient, the catheter sheath does not need to be equipped with a bending function and does not need to be provided with axial tubes of different lengths.

In the above embodiments, thespiral expanding tube 110 or the expandingtube 110 including the axial branch tube, the first annular branch tube and the second annular branch tube may be provided with thesecond channel 112. At this point, the external instrument may be passed directly into thesecond passage 112, however, there is also a risk that the external instrument will become stuck by thedilation tube 110.

In one embodiment, referring to fig. 2 and 3, the catheter assembly further comprises aninner tube 140 disposed through thesecond channel 112, having one end disposed on thehemostasis valve 200 and the other end fixedly connected to theouter tube 120. Theinner tube 140 and theouter tube 120 are preferably fixed by dispensing or welding.

In this embodiment, the passage provided in the region enclosed by the dilatingtube 110 for the external instrument to pass through is athird passage 141 enclosed by theinner tube 140. In this way, when the medical staff fills the fluid into the expandingcavity 111, theouter tube 120 is expanded under the use of the expandingtube 110, and drives the fixedly connectedinner tube 140 to expand together, so that the cross-sectional area of thethird channel 141 formed by the surrounding of theinner tube 140 is increased while the blood vessel of the patient is expanded, thereby facilitating the penetration of external instruments.

Preferably, theinner tube 140 is fixedly connected to theexpansion tube 110, so that when theexpansion tube 110 is expanded, theinner tube 140 is more easily carried along to expand along with theexpansion tube 110. In addition, this arrangement also provides a good fixation for thedilation tube 110, optimizing the structural arrangement of the catheter sheath.

Specifically, the end of theinner tube 140 away from thehemostatic valve 200 is fixedly connected to theouter tube 120 and thedilation tube 110, or the outer sidewall of theinner tube 140 is fixedly connected to thedilation tube 110, which is not limited herein, and theinner tube 140 can be fixedly connected to thedilation tube 110, and is within the protection scope of the present invention. Theinner tube 140 and the expandingtube 110 are preferably fixed by dispensing or welding.

Further, referring to fig. 1, thethird channel 141 is communicated with anevacuation tube 150 for exhausting air in thethird channel 141, preventing air from entering into blood vessels, and further improving the safety of the operation.

In a preferred embodiment, referring to FIG. 1, the catheter assembly further comprises astress diffusion tube 160. Thestress diffusion tube 160 is sleeved on theouter tube 120, one end of the stress diffusion tube is disposed on thehemostatic valve 200, and the other end of the stress diffusion tube is fixed on the outer sidewall of theouter tube 120 to enhance the connection strength between theouter tube 120 and thehemostatic valve 200.

Further, thedilation tube 110 is made of a non-compliant material, such that thedilation tube 110 provides a small radial support force to theouter tube 120, thereby expanding theouter tube 120 and increasing the outer diameter of the catheter assembly while expanding itself. In addition, the non-compliant material may also facilitate the deployment of thedilation tube 110 around thefirst passage 112 through which external instruments may be passed or the second passage through which theinner tube 140 may be passed.

The non-compliant material is preferably PET, PC, PETG, PCTG or the like.

In contrast, theouter tube 120 is made of a compliant material, so that theouter tube 120 can be ensured to maintain a smooth outer surface before and after expansion, and the damage of the catheter sheath to the blood vessel of the patient can be effectively reduced.

Notably, the conformable material is selected to provide anouter tube 120 having a circular or quasi-circular cross-section before and after expansion, further reducing the risk of damage to the patient's blood vessel from the sheath.

In addition, theinner tube 140 of the above-mentioned embodiments should also be made of a compliant material so as to have a certain radial supporting force, so that athird channel 141 with an increased cross-sectional area following the expansion of the expandingtube 110 and theouter tube 120 can be formed to facilitate the penetration of external instruments.

The compliance material is preferably made of PU, pebax and other elastomer materials.

Furthermore, the fluid flowing into or out of theexpansion chamber 111 through thebranch tube 130 is sterile saline containing a contrast medium, so that medical staff can visually see where the catheter assembly is located and whether the catheter assembly is expanded in place, the operation is facilitated, the operation risk is reduced to a certain extent, and the safety is high.

Preferably, referring to fig. 1, thebranch pipe 130 is provided with avalve 170, and the conduction or the blocking of thebranch pipe 130 is realized by controlling the opening and closing of thevalve 170. Thus, after the medical staff fills the fluid into the expandingcavity 111, thevalve 170 can be directly closed, so as to prevent the fluid from flowing out and affecting the expanding effect of the catheter sheath.

Of course, referring to fig. 1, theevacuation pipe 150 mentioned in the above embodiments may also be provided with avalve 170, and the conduction or the blocking of theevacuation pipe 150 is realized by controlling the switch of thevalve 170. Thus, when the medical staff empties the air in the passage for the external instrument to penetrate, thevalve 170 can be directly closed to prevent the external air from entering the passage through thevalve 170 again.

It is preferable that thevalve 170 provided in thebranch pipe 130 and thevalve 170 provided in theevacuation pipe 150 are both three-way stopcocks.

The present invention further provides a method for using an expandable catheter sheath, which may include anexpansion tube 110 and anouter tube 120 covering theexpansion tube 110, wherein anexpansion cavity 111 is disposed in theexpansion tube 110, and at least onebranch tube 130 is connected to theexpansion cavity 111. In addition, thedilation tube 110 encloses a channel through which external instruments can be inserted. Preferably, the passage defined by the expandingtube 110 is connected to theevacuation tube 150.

At this time, the method of using the expandable catheter sheath specifically includes the steps of:

s1, the expandable catheter sheath guides the fluid in theexpansion cavity 111 to the outside through thebranch pipe 130, so that the outer diameter of theouter pipe 120 is at the minimum value, and the expandable catheter sheath is convenient to enter a delivery state. Specifically, the delivery state of the expandable sheath is when the expandable sheath is advanced to the target location.

In practice, the expandable catheter sheath must be used in conjunction with a dilator. First, the medical practitioner first inserts the dilator into the expandable introducer sheath. Then, sterile heparin-containing physiological saline is injected into the channel through theevacuation tube 150, and the gas in the channel is discharged. After the air is exhausted, the expandable catheter sheath is inserted into the blood vessel of the patient, so that the air can be effectively prevented from entering the blood vessel of the patient and harming the life health of the patient.

S2, after the dilator is removed, the expandable sheath guides the external fluid into theexpansion cavity 111 through thebranch tube 130, so that the outer diameter of theouter tube 120 and the size of the channel are gradually increased to a desired size, so that the expandable sheath can enter a use state where the expandable sheath can be passed through by an external instrument.

In this manner, a medical professional may use the external device through the expandable catheter sheath into the patient's vasculature for treatment. The introduced external device is mostly a balloon dilatation catheter or a heart valve delivery system, and of course, other devices may be used, which are not described herein again and fall within the protection scope of the present invention.

After treatment is completed, the expandable sheath again directs the fluid in theexpansion chamber 111 to the outside through thebranch tube 130, so that the outer diameter of theouter tube 120 is at a minimum to facilitate removal of the expandable sheath from the patient's blood vessel.

In this embodiment, before the expandable sheath enters the blood vessel, the fluid in the expansion cavity is used to the outside through the branch tube, so as to avoid the air in the expansion cavity, and thus the sheath cannot enter the blood vessel with the minimum diameter, which affects the usability of the sheath. Therefore, it is desirable for the medical practitioner to repeatedly aspirate several more times to evacuate the air from the expanded lumen before advancing the expandable sheath into the blood vessel.

Preferably, the fluid entering and exiting theexpandable cavity 111 contains a developer, so that medical personnel can image through the developer to timely judge whether the fluid in theexpandable cavity 111 is filled or drained, and the operation is convenient.

In actual production, a fluid pressure detection device can be further arranged in theexpansion cavity 111, and at this time, the medical staff can judge whether the fluid in theexpansion cavity 111 is filled or exhausted according to the detected pressure of the fluid in theexpansion cavity 111. Of course, in addition to the above two embodiments, the medical staff can be assisted by other structural arrangements to judge whether the fluid in theexpansion cavity 111 is completely filled or exhausted, which is not described herein again and falls within the protection scope of the present invention.

In the foregoing embodiments, the descriptions of the respective embodiments have their respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or recited in detail in a certain embodiment.

It should be noted that the above embodiments can be freely combined as necessary. The foregoing is only a preferred embodiment of the present invention, and it should be noted that it is obvious to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and these modifications and improvements should also be considered as the protection scope of the present invention.

Claims

1. An expandable catheter sheath, comprising:

the hemostatic valve is arranged at one end of the catheter component;

when fluid flows into the expansion cavity through the branch tube, the expansion tube expands and expands the outer tube, so that the outer diameter of the catheter assembly is increased;

when fluid flows out of the expansion lumen through the branch tube, the expansion tube and the outer tube contract, reducing the outer diameter of the catheter assembly.

2. The expandable catheter sheath of claim 1,

the pipe wall of the expansion pipe is of a wall-rolling structure and is provided with parts which are overlapped with each other;

when fluid flows out of the expansion cavity through the branch pipe, the expansion pipe contracts, and the overlapped parts of the pipe walls of the expansion pipe are increased.

3. The expandable catheter sheath of claim 2,

the expansion pipe is surrounded and formed with the first passageway that can supply outside apparatus to pass, just first passageway intercommunication has the evacuation pipe.

4. The expandable catheter sheath of claim 1,

the expansion pipes are spirally distributed along the central axis direction of the outer pipe;

5. The expandable catheter sheath of claim 4,

the catheter assembly further comprises an inner tube;

and a third channel for external instruments to pass through is formed in the inner tube in a surrounding manner, and the third channel is communicated with an emptying tube.

6. The expandable catheter sheath of any one of claims 1-5,

the catheter assembly further comprises a stress diffusion tube;

7. The expandable catheter sheath of any one of claims 1-5,

the dilation tube is made of a non-compliant material and the outer tube is made of a compliant material.

8. The expandable catheter sheath of any one of claims 1-5,

the fluid flowing into or out of the inflation lumen through the branch tube is sterile saline containing a contrast agent.

9. The expandable catheter sheath of any one of claims 1-5,

the branch pipe is provided with a valve, and the conduction or the obstruction of the branch pipe is realized by controlling the opening and closing of the valve.

10. A method of using an expandable catheter sheath,

the expandable sheath guides the external fluid into the expansion cavity through the branch tube, so that the outer diameter of the outer tube and the size of the channel are gradually increased to the required size, and the expandable sheath is convenient to enter a use state which can be passed by an external instrument.