CN219271909U - Delivery catheter and interventional blood pump system - Google Patents

Abstract

The present utility model provides a delivery catheter and an interventional blood pump system, the delivery catheter comprising: the device comprises an inner sheath, an outer sheath and a blocking structure, wherein the blocking structure is arranged on the outer wall of the inner sheath and/or the inner wall of the outer sheath; the inner sheath tube is movably arranged on the outer sheath tube in a penetrating manner along the axial direction of the outer sheath tube; when the distal end of the inner sheath tube extends from the distal end of the outer sheath tube, the distal end of the outer sheath tube and the inner sheath tube are sealed by the blocking structure. By means of the arrangement of the blocking structure, the far end of the outer sheath tube and the inner sheath tube can be effectively sealed, blood is prevented or reduced from entering between the outer sheath tube and the inner sheath tube, and thrombus is effectively reduced.

Description

Delivery catheter and interventional blood pump system

Technical Field

The utility model relates to the technical field of medical appliances, in particular to a conveying catheter and an interventional blood pump system.

Background

Delivery catheters are a type of catheter assembly for interventional procedures that are used to intervene and deliver components for a variety of medical uses. Delivery catheters come in a variety of types and configurations, some of which have an inner sheath and an outer sheath, the inner sheath performing a function of use by being movably disposed through the outer sheath. Such as a delivery catheter of a puncture sheath system, or a delivery catheter of an interventional blood pump system, etc. In the conventional delivery catheter, since the inner sheath and the outer sheath are movably assembled, blood easily enters between the inner sheath and the outer sheath to form thrombus, which causes some problems.

Taking a delivery catheter of an interventional blood pump system as an example, the interventional blood pump system is mainly used for first aid of cardiogenic shock and auxiliary circulation during high-risk PCI operation. The heart valve comprises a conveying catheter and a pump head arranged at the far end of the conveying catheter, wherein the pump head is arranged on an aortic valve and can provide flow support of up to 4L/min so as to replace the pumping function of a heart, save the life of a patient suffering from cardiogenic shock, or stabilize the heart state during the operation of a patient suffering from high-risk PCI, reduce the occurrence of arrhythmia, reduce the risk of the operation and ensure the success rate of the high-risk PCI operation.

The pump head of this type of blood pump is generally made of a contractible material, and in use is passed through a delivery catheter into the heart, where it is deployed and secured to the aortic valve to perform the pumping function. The power of the blood pump is provided by an external driving device (such as a blood pump motor) which is connected with the pump head through a flexible shaft. Generally, the delivery catheter of the blood pump has at least two sheath structures, an inner sheath and an outer sheath, respectively. The inner sheath is used for wrapping the flexible shaft so as to prevent the flexible shaft rotating at high speed from contacting with the outside during working; the outer sheath is arranged outside the inner sheath and can move back and forth to perform contraction and expansion operations on the pump head. In order to retract the pump head, a gap is often required between the inner sheath and the outer sheath. Thus, blood is likely to enter the gap between the inner sheath and the outer sheath, and thrombus may be formed after the blood does not flow for a long period of time or is affected by the high temperature of the inner sheath.

Disclosure of Invention

The utility model aims to provide a delivery catheter and an interventional blood pump system, which are used for solving the problem that blood in the existing delivery catheter easily enters between an inner sheath and an outer sheath to form thrombus.

In order to solve the above technical problems, the present utility model provides a delivery catheter, which includes: the device comprises an inner sheath, an outer sheath and a blocking structure, wherein the blocking structure is arranged on the outer wall of the inner sheath and/or the inner wall of the outer sheath;

the inner sheath tube is movably arranged on the outer sheath tube in a penetrating manner along the axial direction of the outer sheath tube; when the distal end of the inner sheath tube extends from the distal end of the outer sheath tube, the distal end of the outer sheath tube and the inner sheath tube are sealed by the blocking structure.

Optionally, when the distal end of the inner sheath extends from the distal end of the outer sheath, a gap is provided between the distal end of the outer sheath and the inner sheath; the occlusion structure comprises an occlusion balloon fixedly disposed on one of the outer sheath and the inner sheath; the occlusion balloon has an expanded state and a contracted state; closing the gap by abutting the other of the outer sheath and the inner sheath when the occlusion balloon is in the expanded state; the occlusion balloon is in the contracted state, and is disengaged from the other of the outer sheath and the inner sheath to unblock the gap to allow the inner sheath to move in the axial direction of the outer sheath.

Optionally, the blocking balloon is fixedly arranged on the inner sheath, the inner sheath fills the cavity, and the filling cavity is communicated with the inner cavity of the blocking balloon and is used for filling fluid circulation.

Optionally, the occlusion balloon comprises a balloon wall circumferentially arranged around the inner sheath, and the balloon wall comprises a first connection section, a support section and a second connection section along the axial direction of the inner sheath; the first connecting section and the second connecting section are respectively and fixedly connected with the outer peripheral wall of the inner sheath tube, and the supporting section is used for expanding and contracting under the action of the filling fluid so as to enable the blocking balloon to be switched between the expanding state and the contracting state.

Optionally, the outer wall of the inner sheath has a radially recessed section within which the axial extent of the balloon wall falls.

Optionally, the balloon wall further comprises a first transition section and a second transition section, the first connection section is in transition connection with the support section through the first transition section, and the second connection section is in transition connection with the support section through the second transition section.

Optionally, when the occlusion balloon is in the expanded state, the support section is straight, arc-shaped or conical along the longitudinal section of the inner sheath in the axial direction.

Optionally, the balloon wall satisfies at least one of the following conditions:

the wall thickness of the balloon wall is 0.02 mm-0.3 mm;

the hardness of the balloon wall is 20A-90D;

when the occlusion balloon is in the contracted state, the outer diameter of the support section is smaller than the outer diameter of the outer sheath tube, and the difference value is 0.01-0.3 mm;

when the occlusion balloon is in the expanded state, the outer diameter of the support section is larger than the outer diameter of the outer sheath, and the difference is 0.01-0.3 mm.

Optionally, the filling cavity extends along the axial direction of the inner sheath, and is closed at the distal end of the inner sheath; the inner sheath tube is provided with a filling port which is arranged along the radial direction, the filling port is positioned in the axial coverage range of the blocking balloon, and the filling cavity is communicated with the inner cavity of the blocking balloon through the filling port.

Optionally, the inner sheath tube is further provided with a main cavity extending through axially, and the filling cavities are arranged at intervals with the main cavity along the radial direction.

Optionally, the delivery catheter further comprises an inner sheath handle assembly disposed at a proximal end of the inner sheath; the inner sheath handle assembly comprises a first hemostasis valve, a first through valve and a second through valve, wherein the first hemostasis valve is arranged along the axial direction of the inner sheath, and the first through valve and the second through valve are arranged at an angle with the axial direction of the inner sheath; the first hemostasis valve is communicated with the main cavity; the first through valve is communicated with the filling cavity; the second pass valve is in communication with the main chamber.

Optionally, the blocking balloon is fixedly arranged on the inner wall of the outer sheath, the outer sheath is provided with a filling cavity, and the filling cavity is communicated with the inner cavity of the blocking balloon and is used for filling fluid circulation.

Optionally, the blocking structure includes a first slope disposed on an inner wall of the distal end of the outer sheath and a second slope disposed on an outer wall of the inner sheath; the first slope surface inclines towards the proximal end, the second slope surface inclines towards the distal end, and when the distal end of the inner sheath tube extends out of the distal end of the outer sheath tube, the first slope surface and the second slope surface form a seal through abutting.

Optionally, the occlusion structure includes a flexible constriction disposed at a distal end of the outer sheath, the flexible constriction having an initial inner diameter less than an outer diameter of the inner sheath when not extruded by the inner sheath; the distal end of the inner sheath extends from the distal end of the outer sheath, and is sealed by squeezing the flexible constriction.

In order to solve the technical problems, the utility model also provides an interventional blood pump system, which comprises the conveying catheter and a pump head; the pump head is connected to the distal end of the delivery catheter.

Optionally, the pump head comprises a runner membrane and a connecting section, wherein the proximal end of the connecting section is coaxially connected with the distal end of the inner sheath, and the outer diameter of the connecting section is smaller than that of the inner sheath; the proximal end of the runner membrane is connected with the peripheral wall of the connecting section.

In summary, in the delivery catheter and the interventional blood pump system provided by the present utility model, the delivery catheter includes: the device comprises an inner sheath, an outer sheath and a blocking structure, wherein the blocking structure is arranged on the outer wall of the inner sheath and/or the inner wall of the outer sheath; the inner sheath tube is movably arranged on the outer sheath tube in a penetrating manner along the axial direction of the outer sheath tube; when the distal end of the inner sheath tube extends from the distal end of the outer sheath tube, the distal end of the outer sheath tube and the inner sheath tube are sealed by the blocking structure.

By means of the arrangement of the blocking structure, the far end of the outer sheath tube and the inner sheath tube can be effectively sealed, blood is prevented or reduced from entering between the outer sheath tube and the inner sheath tube, and thrombus is effectively reduced.

Further, the blocking saccule can be switched between an expansion state and a contraction state, when the blocking saccule is in the expansion state, a gap between the outer sheath tube and the inner sheath tube can be effectively closed, and blood is prevented or reduced from entering between the outer sheath tube and the inner sheath tube; when the blocking balloon is in the contracted state, the gap is unblocked to allow the inner sheath to move along the axial direction of the outer sheath, so that pushing of the inner sheath is not hindered.

Drawings

Those of ordinary skill in the art will appreciate that the figures are provided for a better understanding of the present utility model and do not constitute any limitation on the scope of the present utility model. Wherein:

FIG. 1 is a schematic diagram of an interventional blood pump system according to an embodiment of the present utility model;

FIG. 2 is an enlarged schematic view of portion A of FIG. 1;

FIG. 3 is an enlarged schematic view of portion B of FIG. 1;

FIG. 4 is an enlarged partial schematic view of the junction of the inner sheath and the connecting segment of FIG. 1;

FIG. 5 is a schematic view of a delivery catheter according to an embodiment of the present utility model;

FIG. 6 is a schematic diagram of an application scenario of an interventional blood pump system according to an embodiment of the present utility model;

FIG. 7 is a schematic illustration of an outer sheath, an inner sheath, and an occlusion balloon according to an embodiment of the present utility model;

FIG. 8 is a schematic cross-sectional view of an inner sheath of an embodiment of the present utility model;

FIG. 9 is a schematic longitudinal cross-sectional view of the junction of an inner sheath and a connecting segment according to an embodiment of the present utility model;

FIG. 10 is a schematic view of a first example of an occlusion balloon according to an embodiment of the present utility model;

FIG. 11 is a schematic view of a second example of an occlusion balloon according to an embodiment of the present utility model;

FIG. 12 is a schematic view of a third example of an occlusion balloon according to an embodiment of the present utility model;

FIG. 13 is a schematic view of a fourth example of an occlusion balloon according to an embodiment of the present utility model;

FIG. 14 is a schematic view of an inner sheath handle assembly according to an embodiment of the present utility model;

FIG. 15 is an enlarged schematic view of portion C of FIG. 14;

FIG. 16 is a schematic view of a handle mounting section of an embodiment of the present utility model;

FIG. 17 is a schematic view of an outer sheath handle assembly according to an embodiment of the present utility model;

FIG. 18 is a schematic view of a blocking structure according to another embodiment of the present utility model;

FIG. 19 is a schematic view of an occlusion structure in accordance with yet another embodiment of the present utility model, wherein the inner sheath is not advanced;

FIG. 20 is a schematic view of the inner sheath of FIG. 19 after being ejected;

fig. 21 is a schematic view of a puncture sheath system of an embodiment of the present utility model.

In the accompanying drawings:

01-ascending aorta; 02-aortic valve; 03-left ventricle; 10-a pump head; 11-pigtail catheter; 12-basket; 13-an impeller; 14-basket membrane; 15-a flow channel membrane; 16-connecting section; 20-a delivery catheter; 21-an inner sheath; 211-filling the cavity; 212-a main chamber; 213-filling port; 214-a recessed section; 215-a handle mounting section; 2151-a first incision; 2152-a second incision; 22-an outer sheath; 23-gap; 24-an inner sheath handle assembly; 241-a first hemostasis valve; 242-a first through valve; 243-a second pass valve; 25-an outer sheath handle assembly; 251-a second hemostatic valve; 252-third through valve; 31-a drive assembly; 32-a transmission flexible shaft; 4-occlusion structure; 41-occlusion balloon; 410-lumen; 411-first connection segment; 412-a support section; 413-a second connection section; 414-a first transition section; 415-a second transition section; 421-first ramp; 422-second ramp; 43-flexible constriction; 5-dilator tip.

Detailed Description

The utility model will be described in further detail with reference to the drawings and the specific embodiments thereof in order to make the objects, advantages and features of the utility model more apparent. It should be noted that the drawings are in a very simplified form and are not drawn to scale, merely for convenience and clarity in aiding in the description of embodiments of the utility model. Furthermore, the structures shown in the drawings are often part of actual structures. In particular, the drawings are shown with different emphasis instead being placed upon illustrating the various embodiments.

As used in this disclosure, the singular forms "a," "an," and "the" include plural referents, the term "or" are generally used in the sense of comprising "and/or" and the term "several" are generally used in the sense of comprising "at least one," the term "at least two" are generally used in the sense of comprising "two or more," and the term "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying any relative importance or number of features indicated. Thus, a feature defining "first," "second," "third," or the like, may explicitly or implicitly include one or at least two such features, with "one end" and "another end" and "proximal end" and "distal end" generally referring to the corresponding two portions, including not only the endpoints. The terms "proximal" and "distal" are defined herein with respect to a delivery catheter having one end for intervention into the human body and a manipulation end extending outside the body. The term "proximal" refers to the position of the element closer to the manipulation end of the delivery catheter that extends outside the body, and the term "distal" refers to the position of the element closer to the end of the delivery catheter that is to be introduced into the body and thus further from the manipulation end of the delivery catheter. Alternatively, in a manual or hand-operated application scenario, the terms "proximal" and "distal" are defined herein with respect to an operator, such as a surgeon or clinician. The term "proximal" refers to a location of the element that is closer to the operator, and the term "distal" refers to a location of the element that is closer to the delivery catheter and thus further from the operator. Furthermore, as used in this disclosure, "mounted," "connected," and "disposed" with respect to another element should be construed broadly to mean generally only that there is a connection, coupling, mating or transmitting relationship between the two elements, and that there may be a direct connection, coupling, mating or transmitting relationship between the two elements or indirectly through intervening elements, and that no spatial relationship between the two elements is to be understood or implied, i.e., that an element may be in any orientation, such as internal, external, above, below, or to one side, of the other element unless the context clearly dictates otherwise. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances. Furthermore, directional terms, such as above, below, upper, lower, upward, downward, left, right, etc., are used with respect to the exemplary embodiments as they are shown in the drawings, upward or upward toward the top of the corresponding drawing, downward or downward toward the bottom of the corresponding drawing.

The utility model aims to provide a delivery catheter and an interventional blood pump system, which are used for solving the problem that blood of the existing delivery catheter easily enters between an inner sheath and an outer sheath to form thrombus.

The following description refers to the accompanying drawings.

As described in the background art, in the prior art, since the inner sheath and the outer sheath are movably assembled, blood easily enters between the inner sheath and the outer sheath to form thrombus. Referring to fig. 1 to 6, the following description will be given by taking a delivery catheter of an interventional blood pump system as an example of the delivery catheter, and it should be understood that the delivery catheter is not limited to the delivery catheter of the interventional blood pump system, and the utility model is not limited to the type and application of the delivery catheter, but may be applied to other application scenarios, such as the puncture sheath system shown in fig. 18.

As shown in fig. 1-6, there is shown an interventional blood pump system comprising: pump head 10, conveying conduit 20, driving component 31 and transmission flexible shaft 32; the pump head 10 is located at a distal end for intervention in the human body. The proximal end of the pump head 10 is connected with the driving component 31 through the conveying conduit 20 and the transmission flexible shaft 32, and the driving component 31 drives the impeller of the pump head 10 to act through the transmission flexible shaft 32. Alternatively, in some embodiments, the drive assembly 31 may be an external motor, for example. Optionally, the interventional blood pump system may further comprise a control assembly or other components for monitoring and controlling the interventional blood pump system. The individual components of the interventional blood pump system will be understood by those skilled in the art and will not be described in detail herein.

Referring to fig. 6, in use, the pump head 10 in the collapsed state is inserted through the femoral artery by means of the delivery catheter 20, and through the descending and ascending aorta 01, a portion of the distal end of the pump head 10 passes through the aortic valve 02 and enters the left ventricle 03, and the delivery catheter 20 is operated to expand the pump head 10 from the collapsed state to the expanded state, and the impeller 13 in the pump head 10 is actuated (e.g., rotated) by the distal drive assembly 31 to pump blood from the left ventricle 03 to the ascending aorta 01.

Referring to fig. 1 to 4, in an exemplary embodiment, the pump head 10 includes a pigtail pipe 11, a basket 12, an impeller 13, a basket membrane 14, a runner membrane 15, and a connecting section 16, and the delivery pipe 20 includes an inner sheath 21 and an outer sheath 22. The pigtail catheter 11 is used for assisting the pump head 10 to be fixed in the left ventricle 03, and ensures that the part contacted with the ventricle wall is smoother, so that the damage to the ventricle wall is avoided. Basket 12 is made of a shape memory metal such as nitinol that is capable of compression folding and expansion, in the expanded state, for forming a space for impeller 13 to rotate. The impeller 13 can be made of flexible materials such as silica gel or rubber, and the basket membrane 14 can be coated on the outer wall of the skeleton main body of the basket 13 through thermal shrinkage or dip coating. The runner membrane 15 may be made of a flexible polymer film, and the runner membrane 15 may be connected to the basket membrane 14 at a distal end and the connection section 16 at a proximal end, such as a peripheral wall of the connection section 16, by heat shrinkage or heat melting. Further, the proximal region of the flow field membrane 15 has openings to allow access for blood after it is pumped from the basket 13. The connecting section 16 is a hollow member, and the proximal end of the basket 12 is fitted over the connecting section 16, and the proximal end of the connecting section 16 is coaxially connected to the distal end of the inner sheath 21, so that the entire pump head 10 is connected to the inner sheath 21. As shown in fig. 4, preferably, the outer diameter of the connecting section 16 is smaller than the outer diameter (referred to as the maximum outer diameter) of the inner sheath 21, so that the space between the connecting section 16 and the outer sheath 22 can accommodate the flow path film 15 when the pump head 10 is compressed and folded in the outer sheath 22, reducing the friction between the flow path film 15 and the outer sheath 22, and facilitating pushing of the inner sheath 21 and the pump head 10. In one example, the difference between the outer diameter of the connecting section 16 and the outer diameter of the inner sheath 21 is 0.05mm to 2.5mm.

The transmission flexible shaft 32 is rotatably arranged in the inner sheath tube 21 and the connecting section 16 in a penetrating way, the distal end of the transmission flexible shaft 32 is connected with the impeller 13, the proximal end of the transmission flexible shaft 32 is connected with the driving component 31, the driving component 31 can transmit power to the impeller 13 through the transmission flexible shaft 32, the impeller 13, the basket 12 and the runner membrane 15 form an axial flow pump structure, the impeller 13 rotates to generate a suction force, and blood is pumped to the ascending aorta 01 from the left ventricle 03 through the aortic valve 02.

The components of the basket 12, the impeller 13, the basket membrane 14, the runner membrane 15 and the like can be radially contracted or folded. The inner sheath 21 is axially movable relative to the outer sheath 22, and when the pump head 10 is loaded or is ready to be withdrawn after the end of the operation, the outer sheath 22 is moved distally to radially constrain the various collapsible components of the pump head 10 so that the outer diameter of the pump head 10 is contracted to no greater than the inner diameter of the outer sheath 22 and fully received into the outer sheath 22, completing the collapsed receiving. The outer sheath 22 serves to constrain radial expansion of the pump head 10 and serves to deliver the pump head 10 to a target location, and the inventors have studied that, due to the presence of the flow path membrane 15, there is at least a gap partially between the inner sheath 21 and the outer sheath 22 so that the flow path membrane 15 can be folded and accommodated therein. If this gap is not blocked, blood is easy to enter into the pump head 10 during the interventional use, and thrombus is formed due to the problems of long-time non-flow, high temperature of the inner sheath 21 (the transmission flexible shaft 32 will rotate at high speed during use and generate certain friction with the inner sheath 21 to cause temperature rise), and the like, so that the safety of the operation is affected.

To solve this problem, an embodiment of the present utility model provides a delivery catheter 20, comprising: an inner sheath 21, an outer sheath 22 and a blocking structure 4, the blocking structure 4 being provided on an outer wall of the inner sheath 21 and/or an inner wall of the outer sheath 22; the inner sheath 21 is movably inserted into the outer sheath 22 in the axial direction of the outer sheath 22; when the distal end of the inner sheath 21 extends from the distal end of the outer sheath 22, the distal end of the outer sheath 22 and the inner sheath 21 are sealed by the occlusion structure 4. Here, the axial direction of the outer sheath 22 refers to the direction in which the central axis of the entire outer sheath 22 is located, and in practice, the outer sheath 22 may bend, and the axial direction thereof may bend accordingly. For example, in the state shown in fig. 1, the outer sheath 22 is disposed along the horizontal direction, and then the axial direction thereof is the horizontal direction of fig. 1, and the axial direction of the inner sheath 21 can also be understood by referring to the axial direction of the outer sheath 22, in combination with reference to fig. 1. So configured, by the provision of the blocking structure 4, the distal end of the outer sheath 22 and the inner sheath 21 can be effectively sealed, blood is prevented or reduced from entering between the outer sheath 22 and the inner sheath 21, and thrombus formation is effectively reduced.

Referring to fig. 7, in one embodiment, when the distal end of the inner sheath 21 extends from the distal end of the outer sheath 22, a gap 23 is provided between the distal end of the outer sheath 22 and the inner sheath 21; the occlusion structure 4 comprises an occlusion balloon 41, the occlusion balloon 41 being fixedly arranged on one of the outer sheath 22 and the inner sheath 21; when the occlusion balloon 41 is in the expanded state, the gap 23 is closed by abutting against the other of the outer sheath 22 and the inner sheath 21; when the occlusion balloon 41 is in the contracted state, it is separated from the other of the outer sheath 22 and the inner sheath 21 to release the closure of the gap 23, so that the inner sheath 21 is allowed to move in the axial direction of the outer sheath 22. So configured, the occlusion balloon 41 is capable of transitioning between an expanded state and a contracted state, and when the occlusion balloon 41 is in the expanded state, the gap 23 between the outer sheath 22 and the inner sheath 21 is effectively closed, preventing or reducing blood from entering between the outer sheath 22 and the inner sheath 21; while when the occlusion balloon 41 is in the contracted state, the closure of the gap 23 is released to allow the inner sheath 21 to move in the axial direction of the outer sheath 22, so that the pushing of the inner sheath 21 is not hindered.

Referring to fig. 8 and 9, in one example, the occlusion balloon 41 is fixedly disposed on the inner sheath 21, and the inner sheath 21 has an inflation lumen 211, and the inflation lumen 211 is in communication with the inner lumen 410 of the occlusion balloon 41 for circulating inflation fluid (such as physiological saline or contrast agent, but not limited to liquid, and some embodiments may be gas). Optionally, the inner sheath 21 further has a main cavity 212 extending axially therethrough, and the filling cavities 211 are radially spaced from the main cavity 212. Main cavity 212 is configured for movable threading of drive flexible shaft 32. The inner diameter of main cavity 212 is slightly larger than the outer diameter of drive flexible shaft 32, and the difference between the inner diameter of main cavity 212 and the outer diameter of drive flexible shaft 32 is 0.05 mm-0.3 mm. In this example, inner sheath 21 is a dual lumen tube having both a filling lumen 211 and a main lumen 212. Preferably, main lumen 212 is centered within inner sheath 21 and filling lumen 211 is offset to one side, with the inner diameter of filling lumen 211 preferably being 0.05mm to 1mm. Of course, the filling cavity 211 need not be provided in the inner sheath 21, but may be a separate lumen attached to the inner sheath 21, and the present utility model is not limited thereto.

Alternatively, referring to fig. 7 and 9, the filling cavity 211 extends along the axial direction of the inner sheath 21, and the filling cavity 211 is closed at the distal end of the inner sheath 21; the inner sheath 21 has a filling port 213 opened in a radial direction, the filling port 213 is located in an axial coverage area of the occlusion balloon 41, and the filling cavity 211 is communicated with the inner cavity 410 of the occlusion balloon 41 through the filling port 213. The inflation lumen 211 is closed at the distal end of the inner sheath 21 to prevent inflation fluid from exiting the distal end of the inflation lumen 211 and failing to inflate into the lumen 410 of the occlusion balloon 41. The filling opening 213 may be, for example, a cut formed on the wall of the inner sheath 21, for example, it may be implemented by cutting or punching, and the shape of the filling opening 213 may be, for example, elliptical or circular, etc., and the shape and size of the filling opening 213 are not limited in the present utility model. It will be appreciated that cutting or perforating the wall of inner sheath 21 should be done to communicate with inflation lumen 211 but not to main lumen 212 to prevent inflation fluid from flowing from inflation lumen 211 into main lumen 212 and not into lumen 410 of occlusion balloon 41.

Referring to fig. 10-13, several preferred examples of occlusion balloons 41 are shown. Preferably, the occlusion balloon 41 comprises a balloon wall circumferentially arranged around the inner sheath 21, the balloon wall comprising a first connection section 411, a support section 412 and a second connection section 413 in the axial direction of the inner sheath 21; the first connection section 411 and the second connection section 413 are fixedly connected to the outer peripheral wall of the inner sheath 21, respectively, and the support section 412 is configured to expand and contract (refer to expansion and contraction in the radial direction of the inner sheath 21) under the action of the filling fluid, so that the occlusion balloon 41 is switched between the expanded state and the contracted state. It will be appreciated that the first connecting section 411 and the second connecting section 413 extend in a substantially straight shape along the axial direction of the inner sheath 21, and the inner wall of the first connecting section 411 and the inner wall of the second connecting section 413 are both attached to the outer peripheral wall of the inner sheath 21 and are fixedly connected by glue or welding, so that an inner cavity 410 for accommodating filling fluid is formed between the supporting section 412 and the outer peripheral wall of the inner sheath 21. It will be appreciated that since both ends of the balloon wall in the axial direction (i.e., the first connection section 411 and the second connection section 413) are secured to the inner sheath 21, the inner lumen 410, when inflated, will expand the support section 412 radially outwardly, i.e., transition the occlusion balloon 41 to the expanded state. Conversely, upon evacuation of the inflation fluid within lumen 410, support segment 412 may radially contract under its own elastic action, i.e., transition occlusion balloon 41 to the contracted state. In this way, a reliable driving of the occlusion balloon 41 is achieved, facilitating a change of state of the occlusion balloon 41.

Optionally, the balloon wall satisfies at least one of the following conditions:

1. the wall thickness of the balloon wall is 0.02 mm-0.3 mm. If the wall thickness of the balloon wall is too small, the occlusion balloon 41 is prone to bursting; if the wall thickness of the balloon wall is too large, the filling pressure required is greater and the volume of the occlusion balloon 41 is correspondingly increased, resulting in an increase in friction.

2. The hardness of the balloon wall is 20A-90D. To avoid excessive deformation of the distal portion of the support section 412, the balloon wall should have a certain stiffness (e.g., 20A-90D) and less compliance. The selection of a balloon wall of suitable hardness also facilitates filling of occlusion balloon 41 and sealing of gap 23.

3. When the occlusion balloon 41 is in the contracted state, the outer diameter of the support section 412 (meaning the expanded outer diameter of the support section 412 when it is unconstrained by the outer sheath 22) is smaller than the outer diameter of the outer sheath 22 (meaning the outer diameter of the outer sheath 22 when it is not extruded by the support section 412) by a difference of 0.01mm to 0.3mm. If the difference is too small, the friction between the occlusion balloon 41 and the outer sheath 22 is too large, and the inner sheath 21 is not easy to move; if the difference is too large, it is difficult to seal completely after the occlusion balloon 41 is converted to the expanded state and deployed.

4. When the occlusion balloon 41 is in the expanded state, the outer diameter of the support section 412 (which means the expanded outer diameter of the support section 412 when it is unconstrained by the outer sheath 22) is larger than the outer diameter of the outer sheath 22 (which means the outer diameter of the outer sheath 22 when it is not extruded by the support section 412), and the difference is 0.01mm to 0.3mm. If the difference is too small, a gap is easily formed between the support section 412 and the outer sheath 22, and the sealing is not easily completed; if the difference is too large, the outer sheath 22 is liable to form a fold and a slit, resulting in poor sealing effect.

Optionally, when the occlusion balloon 41 is in the expanded state, at least a portion of the occlusion balloon 41 (e.g., the support section 412) is straight (as shown in fig. 10 and 11), arcuate (as shown in fig. 12), or tapered (as shown in fig. 13) along the longitudinal cross-section of the inner sheath 21 in the axial direction. Of course, those skilled in the art may select other shapes of support segments 412, as the utility model is not limited in this regard.

Further, in some embodiments, the balloon wall further comprises a first transition section 414 and a second transition section 415, the first connection section 411 is in transitional connection with the support section 412 through the first transition section 414, and the second connection section 413 is in transitional connection with the support section 412 through the second transition section 415. The transitional connection is that the connection is smoother through the sloping surface (shown in figure 10) or the cambered surface (shown in figure 11), rather than forming the diameter mutation similar to the step surface, so as to reduce the stress concentration phenomenon.

Preferably, referring to fig. 7 in combination, the outer wall of the inner sheath 21 has a radially recessed section 214, and the axial extension of the balloon wall falls within the recessed section 214. The inner sheath 21 does not maintain a uniform outer diameter in the axial direction, and its outer wall may be recessed inwardly at the section where the occlusion balloon 41 is adapted to be positioned, forming a recessed section 214 of slightly smaller outer diameter. It will be appreciated that the axial length of the recessed section 214 is not less than the axial length of the occlusion balloon 41 such that the axial extent of the balloon wall falls within the recessed section 214. So configured, when occlusion balloon 41 is in the contracted state, at least a portion of the balloon wall can be received within the radial recess of recessed section 214, minimizing the extent to which the balloon wall protrudes beyond the outer peripheral contour of inner sheath 21, minimizing the frictional forces between occlusion balloon 41 and outer sheath 22, facilitating the pushing of inner sheath 21 and pump head 10.

The above embodiment specifically describes a scheme in which the occlusion balloon 41 is fixed to the inner sheath 21. In accordance with the principles disclosed herein, it will be appreciated by those skilled in the art that in other embodiments, occlusion balloon 41 is not limited to being secured to inner sheath 21, but rather may be secured to the inner wall of outer sheath 22, with the outer sheath 22 having a corresponding inflation lumen and inflation port, the inflation lumen being in communication with the lumen of occlusion balloon 41 for inflation fluid communication to facilitate inflation of occlusion balloon 41. Which may also close the gap 23.

Referring to fig. 14 and 15, and referring to fig. 5 in combination, in one example, the delivery catheter 20 further includes an inner sheath handle assembly 24, wherein the inner sheath handle assembly 24 is disposed at the proximal end of the inner sheath 21 and fixedly connected to the proximal end of the inner sheath 21, such as by glue connection, welding, or integral injection molding. The inner sheath handle assembly 24 includes a first hemostasis valve 241, a first through valve 242, and a second through valve 243, the first hemostasis valve 241 being disposable along the axial direction of the inner sheath 21, for example, while the first through valve 242 and the second through valve 243 are each disposed at an angle to the axial direction of the inner sheath 21 such that the entire inner sheath handle assembly 24 generally forms a three-pronged shape. The primary hemostasis valve 241 communicates with the main lumen 212 of the inner sheath 21 and is operable to allow the motorized flexible shaft 32 to pass therethrough and into the main lumen 212. The first through valve 242 communicates with the filling chamber 211 for, in use, injecting or pumping filling fluid R1 into the filling chamber 211. Second pass valve 243 is in communication with main lumen 212 for, in use, injecting a perfusion fluid R2 (e.g., saline or contrast media, etc.) into main lumen 212 such that the perfusion fluid flows distally with main lumen 212.

Optionally, the first through valve 242 and the second through valve 243 are connected at the same axial position of the inner sheath 21 to form a through valve outlet; the distance from the outlet of the through valve to the proximal end of the inner sheath 21 is 0.1mm to 10mm. Here, the distance from the through valve outlet to the proximal end of the inner sheath 21 refers to the axial distance between the center of the communication port between the first through valve 242 (or the second through valve 243) and the inner sheath 21 and the proximal end of the inner sheath 21. If the distance is too small, the proximal end of the inner sheath 21 easily blocks the through valve outlet; if the distance is too large, the strength of the connection of the inner sheath handle assembly 24 to the inner sheath 21 may be insufficient.

Referring to fig. 15 and 16, in an alternative example, the proximal end of inner sheath 21 includes handle mounting section 215 that includes first and second cutouts 2151 and 2152, with first and second cutouts 2151 and 2152 being formed by a punching or cutting process. Wherein the depth of first cutout 2151 is controlled to communicate only with filling chamber 211 and second cutout 2152 communicates only with main chamber 212. Further, the first through valve 242 is disposed at the first cutout 2151, and the second through valve 243 is disposed at the second cutout 2152.

Referring to fig. 17 in combination with fig. 5, in one example, the delivery catheter 20 further includes an outer sheath handle assembly 25, wherein the outer sheath handle assembly 25 is disposed at the proximal end of the outer sheath 22 and is fixedly connected to the proximal end of the outer sheath 22, such as by glue connection, welding, or integral injection molding. The outer sheath handle assembly 25 includes a second hemostasis valve 251 and a third through valve 252, the second hemostasis valve 251 being disposable along the axial direction of the outer sheath 22, for example, and the third through valve 252 being disposed at an angle to the axial direction of the outer sheath 22. The second hemostasis valve 251 is communicated with the inner cavity of the outer sheath tube 22, and is used for the inner sheath tube 21 to penetrate through in use. The third through valve 252 is also in communication with the lumen of the outer sheath 22 for the injection of irrigation fluid and the like. Optionally, the inner diameter of the outer sheath tube 22 is slightly larger than the outer diameter of the inner sheath tube 21 by a difference of 0.01mm to 0.2mm, so that the inner sheath tube 21 can freely move in and out of the outer sheath tube 22. Preferably, the total length of the inner sheath 21 is greater than the total length of the outer sheath 22, and the difference in length between them is 0.1mm to 300mm. Optionally, the third through valve 252 is connected to the outer sheath 22 to form a through valve outlet; the distance from the through valve outlet to the proximal end of the outer sheath 22 is 0.1mm to 10mm. Here, the distance from the outlet of the through valve to the proximal end of the outer sheath 22 refers to the axial distance between the center of the communication port between the third through valve 252 and the outer sheath 22 and the proximal end of the outer sheath 22. If the distance is too small, the proximal end of the outer sheath 22 will easily block the through valve outlet; if the distance is too large, the strength of the connection of the outer sheath handle assembly 25 to the outer sheath 22 may be insufficient.

It should be noted that, the blocking structure 4 is not limited to the blocking balloon 41 described above, referring to fig. 18, in another embodiment, the blocking structure 4 includes a first slope 421 disposed on the distal inner wall of the outer sheath 22 and a second slope 422 disposed on the outer wall of the inner sheath 21; the first slope 421 is inclined in a proximal direction, the second slope 422 is inclined in a distal direction, and when the distal end of the inner sheath 21 extends from the distal end of the outer sheath 22, the first slope 421 and the second slope 422 are closed by abutting. Optionally, the axial angle of the first slope 421 relative to the outer sheath 22 is the same as the axial angle of the second slope 422 relative to the inner sheath 21, so that the first slope 421 and the second slope can be closely abutted when abutted, and the sealing effect is improved.

Referring to fig. 19 and 20, in yet another embodiment, the blocking structure 4 includes a flexible constriction 43 disposed at the distal end of the outer sheath 22, the flexible constriction 43 having an initial inner diameter less than the outer diameter of the inner sheath 21 when not compressed by the inner sheath 21 (as shown in fig. 19); the distal end of the inner sheath 21 extends from the distal end of the outer sheath 22 (as shown in fig. 20) and is sealed by squeezing the flexible constriction 43. The flexible constriction 43 may be made of a resilient material, for example, which is capable of expanding outwardly under compression of the inner sheath 21 and fitting against the outer wall of the inner sheath 21, thereby forming a reliable seal.

Referring to fig. 21, which shows an example of another application scenario of a delivery catheter, fig. 21 shows a puncture sheath system, which delivery catheter likewise comprises an inner sheath 21, an outer sheath 22 and an occlusion structure 4. The puncture sheath system further comprises a dilator tip 5 attached to the distal end of the inner sheath 21. It will be appreciated that the occluding structure 4 may be any of the structures described above that are also capable of forming a seal with the distal end of the outer sheath 22 and the inner sheath 21.

In summary, the present utility model provides a delivery catheter comprising: an inner sheath, an outer sheath, and a blocking structure; the inner sheath tube is movably arranged on the outer sheath tube in a penetrating manner along the axial direction of the outer sheath tube, and the blocking structure is arranged on the outer wall of the inner sheath tube and/or the inner wall of the outer sheath tube; when the distal end of the inner sheath tube extends from the distal end of the outer sheath tube, the distal end of the outer sheath tube and the inner sheath tube are sealed by the blocking structure. By means of the arrangement of the blocking structure, the far end of the outer sheath tube and the inner sheath tube can be effectively sealed, blood is prevented or reduced from entering between the outer sheath tube and the inner sheath tube, and thrombus is effectively reduced. Further, the blocking saccule can be switched between an expansion state and a contraction state, when the blocking saccule is in the expansion state, a gap between the outer sheath tube and the inner sheath tube can be effectively closed, and blood is prevented or reduced from entering between the outer sheath tube and the inner sheath tube; when the blocking balloon is in the contracted state, the gap is unblocked to allow the inner sheath to move along the axial direction of the outer sheath, so that pushing of the inner sheath is not hindered.

It should be noted that the above embodiments may be combined with each other. The above description is only illustrative of the preferred embodiments of the present utility model and is not intended to limit the scope of the present utility model, and any alterations and modifications made by those skilled in the art based on the above disclosure shall fall within the scope of the appended claims.

Claims (16)

1. A delivery catheter, comprising: the device comprises an inner sheath, an outer sheath and a blocking structure, wherein the blocking structure is arranged on the outer wall of the inner sheath and/or the inner wall of the outer sheath;

the inner sheath tube is movably arranged on the outer sheath tube in a penetrating manner along the axial direction of the outer sheath tube; when the distal end of the inner sheath tube extends from the distal end of the outer sheath tube, the distal end of the outer sheath tube and the inner sheath tube are sealed by the blocking structure.

2. The delivery catheter of claim 1, wherein the distal end of the inner sheath has a gap between the distal end of the outer sheath and the inner sheath when the distal end of the inner sheath extends from the distal end of the outer sheath; the occlusion structure comprises an occlusion balloon fixedly disposed on one of the outer sheath and the inner sheath; the occlusion balloon has an expanded state and a contracted state; closing the gap by abutting the other of the outer sheath and the inner sheath when the occlusion balloon is in the expanded state; the occlusion balloon is in the contracted state, and is disengaged from the other of the outer sheath and the inner sheath to unblock the gap to allow the inner sheath to move in the axial direction of the outer sheath.

3. The delivery catheter of claim 2, wherein the occlusion balloon is fixedly disposed on the inner sheath, the inner sheath filling lumen being in communication with the lumen of the occlusion balloon for filling fluid communication.

4. The delivery catheter of claim 3, wherein the occlusion balloon comprises a balloon wall disposed circumferentially around the inner sheath, the balloon wall comprising a first connection section, a support section, and a second connection section along an axial direction of the inner sheath; the first connecting section and the second connecting section are respectively and fixedly connected with the outer peripheral wall of the inner sheath tube, and the supporting section is used for expanding and contracting under the action of the filling fluid so as to enable the blocking balloon to be switched between the expanding state and the contracting state.

5. The delivery catheter of claim 4, wherein the outer wall of the inner sheath has a radially recessed section within which the axial extent of the balloon wall falls.

6. The delivery catheter of claim 4, wherein the balloon wall further comprises a first transition section and a second transition section, the first connection section being in transitional connection with the support section through the first transition section, the second connection section being in transitional connection with the support section through the second transition section.

7. The delivery catheter of claim 4, wherein the support section is straight, arcuate or tapered in longitudinal cross-section along the axial direction of the inner sheath when the occlusion balloon is in the expanded state.

8. The delivery catheter of claim 4, wherein the balloon wall satisfies at least one of the following conditions:

the wall thickness of the balloon wall is 0.02 mm-0.3 mm;

the hardness of the balloon wall is 20A-90D;

when the occlusion balloon is in the contracted state, the outer diameter of the support section is smaller than the outer diameter of the outer sheath tube, and the difference value is 0.01-0.3 mm;

when the occlusion balloon is in the expanded state, the outer diameter of the support section is larger than the outer diameter of the outer sheath, and the difference is 0.01-0.3 mm.

9. The delivery catheter of claim 3, wherein the filling lumen extends axially of the inner sheath and is closed at a distal end of the inner sheath; the inner sheath tube is provided with a filling port which is arranged along the radial direction, the filling port is positioned in the axial coverage range of the blocking balloon, and the filling cavity is communicated with the inner cavity of the blocking balloon through the filling port.

10. The delivery catheter of claim 9, wherein the inner sheath further has a main lumen extending axially therethrough, the filling lumen being radially spaced from the main lumen.

11. The delivery catheter of claim 10, further comprising an inner sheath handle assembly disposed at a proximal end of the inner sheath; the inner sheath handle assembly comprises a first hemostasis valve, a first through valve and a second through valve, wherein the first hemostasis valve is arranged along the axial direction of the inner sheath, and the first through valve and the second through valve are arranged at an angle with the axial direction of the inner sheath; the first hemostasis valve is communicated with the main cavity; the first through valve is communicated with the filling cavity; the second pass valve is in communication with the main chamber.

12. The delivery catheter of claim 2, wherein the occlusion balloon is fixedly disposed on an inner wall of the outer sheath, the outer sheath having an inflation lumen in communication with an inner lumen of the occlusion balloon for fluid communication.

13. The delivery catheter of claim 1, wherein the occlusion structure comprises a first ramp disposed on a distal inner wall of the outer sheath and a second ramp disposed on an outer wall of the inner sheath; the first slope surface inclines towards the proximal end, the second slope surface inclines towards the distal end, and when the distal end of the inner sheath tube extends out of the distal end of the outer sheath tube, the first slope surface and the second slope surface form a seal through abutting.

14. The delivery catheter of claim 1, wherein the occlusion structure comprises a flexible constriction disposed at a distal end of the outer sheath, the flexible constriction having an initial inner diameter less than an outer diameter of the inner sheath when not compressed by the inner sheath; the distal end of the inner sheath extends from the distal end of the outer sheath, and is sealed by squeezing the flexible constriction.

15. An interventional blood pump system comprising the delivery catheter according to any one of claims 1-14, further comprising a pump head; the pump head is connected to the distal end of the delivery catheter.

16. The interventional blood pump system of claim 15, wherein the pump head comprises a flow channel membrane and a connection section, a proximal end of the connection section being coaxially connected to a distal end of the inner sheath, and an outer diameter of the connection section being smaller than an outer diameter of the inner sheath; the proximal end of the runner membrane is connected with the peripheral wall of the connecting section.

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