System for drainage

Abstract

In accordance with a system for vascular drainage, the system comprises a cannula, in particular for use in medical applications, having a distal cannula portion and a proximal cannula portion, where the cannula comprises: a plurality of flexible filaments such that the cannula diameter can vary between a first diameter (D1) and a second diameter (D2); and a tip, a plug, and an elongate member, where the elongate member comprises a tip at a distal end thereof and a plug at a proximal end thereof to form a mandrel, where the plug is configured to be at least partially movably positioned into the proximal cannula portion; and a head element arranged at the distal cannula portion wherein the head element comprises an opening configured to partially receive the distal end of the mandrel such that positioning of the plug at the proximal cannula portion varies the cannula diameter between a first diameter (D1) and a second diameter (D2).

Description

Background Technology

[0001] Cannulation is crucial for extracorporeal circulation to drain blood toward life support systems before it is reinjected into the circulation. For high-flow applications such as cardiopulmonary bypass and extracorporeal membrane oxygenation (ECMO), cannula performance can be critical, as the cannula is typically the narrowest part of the perfusion circuit. Conventional cannula designs are usually based on a straight design, i.e., a straight tube. Therefore, the resistance of this type of cannula increases linearly with cannula length. Consequently, shorter cannulas offer better performance. However, in the case of intravenous cannulas, the distal end of the cannula must be positioned in the right atrium to avoid cannula orifice blockage, which can lead to additional complications.

[0002] Therefore, two methods have been developed to improve venous drainage. One method involves making the cannula wall thinner to obtain a larger cross-sectional area and thus provide less resistance. The other method involves using enhanced venous drainage achieved through a centrifugal pump or vacuum. However, because the latter method requires increased suction, it can lead to cannula orifice blockage and interruption of venous drainage. This phenomenon is a typical finding in clinical cases undergoing minimally invasive cardiac surgery utilizing remote cannulation.

[0003] To overcome this problem, EP 1 248 571 B1 describes a cannula for vascular drainage having a small diameter for insertion into a blood vessel only. The cannula includes a cannula body having a lumen extending between a proximal and a distal end of the cannula, wherein the cannula is made of a flexible material and has at least one mechanism for changing the cannula's configuration between a normal profile configuration and a low profile configuration upon actuation. In the normal profile configuration, the cannula has a large lumen diameter for vascular drainage, and in the low profile configuration, the lumen diameter is reduced to allow insertion of the cannula into the patient's blood vessel.

[0004] Therefore, the cannula includes a watertight coating at its proximal end, such as a flexible material, like a series of interlaced or interwoven threads coated at the proximal end, while at the distal end, blood flows through the uncoated interlaced threads. After the cannula is properly positioned in the blood vessel, the distal end expands to the surface of the blood vessel's inner wall for drainage. The cannula can be inserted onto a guidewire and can be stretched or contracted using a spindle, probe, balloon, pressure mechanism, or retraction mechanism. The distal end of the cannula can be stretched using a spindle.

[0005] At the start of the drainage procedure, a guidewire is placed in the blood vessel to guide the cannula to the desired vascular region. The guidewire is inserted into the cannula through an opening located at the distal end of the cannula and then passes through the interior of the cannula. To convert the cannula to a low-profile configuration for insertion into the patient's blood vessel, i.e., to stretch the flexible wire mesh of the cannula body, a mandrel can be inserted into the lumen of the cannula, i.e., from the proximal end of the cannula to the distal end and onto the guidewire. For this purpose, the mandrel can be tubular to allow it to be guided onto the guidewire for insertion into the lumen of the cannula. At the distal end of the cannula, the mandrel abuts a component. This component forms the end of the cannula, and the flexible wire mesh is attached to this component. At its proximal end, the mandrel includes a plug that can be inserted into the opening located at the proximal end of the cannula, such that due to the difference in length between the cannula and the mandrel, force is applied to this component as the mandrel is further pressed into the opening of the cannula. This force tensions the wire mesh and shifts the sleeve to the desired low-profile configuration. In the low-profile configuration, the sleeve has a specific diameter, meaning the lumen of the sleeve has a smaller diameter than in the normal profile configuration, where the lumen has a larger diameter.

[0006] A wire mesh is attached to a component located at the distal end of the cannula. To prevent the wire mesh from separating from the component due to deformation caused by external forces (such as pressure) or internal forces (such as thermal expansion), this component possesses mechanical strength such that deformability due to tension and compression does not affect the shape of the component. Furthermore, because this component forms the distal end of the cannula, it is used to guide the cannula through the blood vessel, and therefore, when the guidewire is attached to this component, it is tapered, for example, tip-shaped, specifically maintaining a tip shape to reduce snagging or hooking inside the blood vessel and further reduce mechanical resistance when the cannula initially penetrates through the small opening in the uppermost layer of skin to reach the blood vessel. Therefore, the component must provide a certain level of mechanical strength due to the various requirements imposed on it based on the application. However, due to the strength of the component and the associated risk of blood vessel damage, inserting the cannula along the path through the blood vessel to the desired location presents challenges.

[0007] Furthermore, the problem is that the guidewire must be pulled out of the cannula via a mandrel before actual drainage can begin, and the particularly angled path of the blood vessel facilitates guidewire kinking. The opening at the distal end of the component (through which the guidewire is pulled back) has a hard edge, and therefore promotes guidewire kinking as the guidewire is first pulled through the end of the cannula and then through the mandrel.

[0008] Therefore, the object of the present invention is to provide an improved vascular drainage system that improves cannula guidance and reduces the risk of vascular injury during cannula insertion into the relevant site within the vascular tract. It also aims to reduce the likelihood of guidewire kinking, particularly during guidewire retraction, and / or facilitate the retraction of already kinked guidewires. If the guidewire cannot be retracted, the entire cannula must be removed and the procedure restarted.

[0009] At the start of drainage, and as long as the mandrel is still stretching the cannula (i.e., the cannula is in a low-profile configuration), fluid (e.g., blood from the patient) cannot penetrate into the interior of the cannula because the large opening formed by the wire mesh inside the cannula is blocked by the surface of the mandrel. When the mandrel is removed and the cannula is switched to a normal-profile configuration, fluid or blood flows through the opening in the cannula and displaces some of the air present there. However, since air must be absent from the drainage circuit, the cannula must have a mechanism to allow air to escape.

[0010] To overcome this problem, EP 2 341 850 B1 describes a plug that allows the air required for venting the sleeve to pass through. Therefore, the plug can be a porous plug, or the plug can be molded with slits for venting. The advantage of slits is that they can be easily implemented with simple modifications to the mold, thus enabling low-cost production of the plug. However, the disadvantage of slits is that, because the slit is located on the outside of the plug, it is susceptible to contamination and blockage by impurities.

[0011] Therefore, another object of the present invention is to provide an alternative solution to the problem of cannula venting. Summary of the Invention

[0012] This problem is solved by the subject matter of the independent claims, namely, by the system for vascular drainage according to claim 1, the cannula according to claim 16, the mandrel according to claim 17, and the parts kit according to claim 15. Further preferred embodiments of the invention are the subject matter of the dependent claims.

[0013] The vascular drainage system according to the invention includes a cannula, particularly for use in medical applications, having a distal cannula portion and a proximal cannula portion, wherein the cannula comprises: a plurality of flexible filaments such that the cannula can vary between a normal profile configuration and a low profile configuration; and an end, a plug, and an elongated member, wherein the elongated member includes an end at its distal end and a plug at its proximal end to form a mandrel, wherein the plug is configured to be at least partially movably positioned in the proximal cannula portion; and a head element disposed at the distal cannula portion, wherein the head element includes an opening configured to partially receive the distal end of the mandrel, such that the positioning of the plug at the proximal cannula portion allows the cannula to vary between a normal profile configuration and a low profile configuration.

[0014] Drainage is a medical treatment method. It is used to drain or aspirate pathological or increased body fluids or gases in order to restore a normal state. In principle, there is a distinction between internal and external drainage. In internal drainage, obstructions are bypassed through surgery (e.g., minimally invasive surgery), or accumulated fluid is drained into a hollow organ (e.g., the stomach or intestines). In external drainage, drainage is from the inside of the body to the outside.

[0015] For example, a vascular drainage system according to the "Seldinger method" typically includes a guidewire that is inserted into the patient's blood vessel before drainage, and the guidewire is used to guide a cannula to a hollow organ, wherein the cannula is, in principle, a flexible hollow tube through which the fluid to be drained is guided to the outside of the blood vessel, that is, out of the patient's body.

[0016] The cannula is designed to be inserted into a hollow organ, which may be selected from, for example, a vein, artery, urethra, ureter, intestine, esophagus, trachea, bronchus, pleural cavity and / or peritoneum.

[0017] The use of cannulas in a medical setting includes methods such as placing the cannulas in their low-profile configuration, inserting the cannulas into the patient's hollow organ at the insertion point, and restoring the cannulas to their normal profile configuration. In the normal profile configuration, the cannulas expands, particularly at its distal end, i.e., distal to the insertion point, to the diameter of the hollow organ or to the maximum diameter of the cannulas body (i.e., the lumen formed by the cannulas body).

[0018] In the low-profile configuration of the cannula, the diameter of the cannula is reduced compared to the normal profile configuration to allow insertion into a hollow organ, such as a blood vessel. In the low-profile configuration, a wire mesh (i.e., the flexible filaments of the cannula) forms the cannula body, thereby defining the cannula lumen. In the low-profile configuration, the flexible filaments are substantially taut compared to the normal profile configuration. The cannula diameter refers to the diameter of the lumen (i.e., the inner diameter of the cannula) and / or the diameter of the cannula body (i.e., the outer diameter of the cannula). The diameter involves multiple diameters that appear in the normal profile configuration due to the actual shape of the cannula body and / or lumen, but when the cannula enters the low-profile configuration, the diameter changes due to the tension of the cannula.

[0019] Therefore, the cannula diameter can vary between a first diameter (D1) and a second diameter (D2). The first diameter (D1) includes a low-profile configuration, and the second diameter (D2) includes a normal-profile configuration. When the cannula is in its normal-profile configuration during use, the lumen diameter distal to the insertion point varies relative to the diameter of the surrounding blood vessel. Furthermore, when the cannula is in its normal-profile configuration during use, the portion of the cannula distal to the insertion point supports the inner surface of the surrounding blood vessel. When the cannula is in its low-profile configuration, a portion of the cannula is characterized by a narrow diameter of the lumen, suitable for insertion into the object to be cannulated and into smaller access blood vessels. However, the cannula can be placed in the low-profile configuration before, during, or after insertion.

[0020] To allow for this variation in the sleeve diameter, the sleeve includes flexible filaments, i.e., an elastic body at least partially formed by the flexible filaments. The multiple flexible filaments may comprise one or more materials selected from metals, shape memory metals, alloys, plastics, textile fibers, synthetic fibers, and / or combinations thereof. For example, the metal may be stainless steel. Furthermore, the multiple flexible filaments may have shapes selected from circular, elliptical, flat, triangular, rectangular, and combinations thereof. In one embodiment, the multiple flexible filaments are textile fibers. The multiple flexible filaments may be woven together, knitted together, or interwoven. Alternatively, the multiple flexible filaments may be interlaced.

[0021] An elastic filament surrounds a volume, which can be defined as the lumen of the cannula, and the spatial extent of this volume can vary due to the elastic filament. The lumen has a distal end pointing towards the insertion point and a proximal end pointing in the opposite direction away from the insertion point (i.e., away from the patient). Therefore, the cannula comprises a distal cannula portion and a proximal cannula portion, the distal cannula portion being the part closer to the insertion point and the proximal cannula portion being the part farther from the insertion point.

[0022] To alter the spatial extent of the cannula's lumen, i.e., to tension the cannula through a configuration from a normal to a low-profile configuration, a mandrel is inserted from the proximal cannula portion into the lumen and then into the distal cannula portion. To allow variation in the cannula's diameter or lumen between the low-profile and normal profile configurations, the mandrel engages the distal portion of the cannula and is then pushed further into the lumen from the proximal portion, generating a force that tensions the cannula's flexible filament and thus changes the cannula's diameter from the normal profile to the low-profile configuration. After the mandrel is removed, the cannula expands to its unclamped diameter, particularly since the flexible filament tends to exhibit its original normal shape (like a spring), which is associated with a larger diameter lumen at the insertion point. The mandrel may (particularly for medical applications) comprise a hollow tube and can be configured for guidewire insertion through the hollow tube of the mandrel. In this configuration, the guidewire passes through the mandrel to the distal end of the cannula, exits through the distal end of the cannula, and enters a hollow organ (e.g., a vein) to further guide the cannula through the blood vessel (e.g., a vein) to the application site. The guidewire can then be inserted into or removed from the hollow organ via the mandrel positioned within the body of the cannula. Alternatively, the mandrel can be removed from the cannula while the guidewire remains positioned within both the cannula and the hollow organ.

[0023] To adapt the mandrel for tensioning the cannula, the mandrel includes an end, a plug, and an elongated member. The elongated member may include a hollow tube surrounding the end, and the plug of the mandrel may include an opening configured for guidewire insertion.

[0024] The end is located at the distal end of the mandrel. The plug is located at the proximal end of the mandrel, and an elongated member connects the plug to the end, thereby forming the mandrel. Therefore, the distal end of the mandrel at least partially includes the end and the elongated member (i.e., the distal end of the elongated member). And, the proximal end of the mandrel at least partially includes the end and the elongated member (i.e., the proximal end of the elongated member). To tension the sleeve, the distal end of the mandrel engages the distal end of the sleeve. For this purpose, the distal end of the sleeve includes a head element with an opening. The opening of the head element is designed to partially receive the distal end of the mandrel. This means that a portion of the distal end of the mandrel engages in the opening, in such a way that tension can be established to tension the sleeve on the mandrel, and wherein another portion of the distal end of the mandrel is not engaged in the opening, for example, through the opening.

[0025] The present invention also relates to a mandrel for use in a cannula having a distal cannula portion and a proximal cannula portion and a plurality of flexible filaments, the mandrel including an end, a plug and an elongated member, wherein the elongated member includes an end located at its distal end and a plug located at its proximal end to form the mandrel, wherein the plug is configured to be at least partially movably positioned in the proximal cannula portion.

[0026] The present invention also relates to a cannula, particularly a cannula for use in medical applications, the cannula having: a distal cannula portion and a proximal cannula portion, wherein the cannula includes a plurality of flexible filaments such that the cannula can vary between a normal profile configuration and a low profile configuration, for example, between a first diameter (D1) and a second diameter (D2); and a head element disposed at the distal cannula portion, wherein the head element includes an opening, wherein the opening of the head element includes a first diameter (R1) and a second diameter (R2).

[0027] The present invention also relates to a parts kit comprising: a cannula, particularly for use in medical applications, the cannula having: a distal cannula portion and a proximal cannula portion, wherein the cannula includes a plurality of flexible filaments such that the cannula can be varied between a normal profile configuration and a low profile configuration, for example, the cannula diameter varying between a first diameter (D1) and a second diameter (D2); and a head element disposed at the distal cannula portion, wherein the head element includes an opening, and

[0028] A mandrel includes an end, a plug, and an elongated member, wherein the elongated member includes an end located at its distal end and a plug located at its proximal end to form a mandrel, wherein the plug is configured to be at least partially movably positioned within a proximal cannula portion, and

[0029] The opening of the head element is configured to partially receive the distal end of the mandrel, such that the positioning of the plug at the proximal cannula portion causes the cannula to vary between a normal profile configuration and a low profile configuration, for example, the cannula diameter varies between a first diameter (D1) and a second diameter (D2).

[0030] In a preferred embodiment of the system, including the spindle and cannula, the distal end is configured to extend partially through the opening, such that the distal end advantageously supports the guide cannula through a blood vessel. Therefore, the head element disposed at the distal end of the cannula includes an opening large enough to engage the distal end of the spindle with the guidewire. Thus, when the spindle is removed, the guidewire has more space within the opening of the head element for movement. Therefore, if in a medical application the guidewire remains within the cannula and the spindle is removed from the cannula, the guidewire advantageously has a larger access opening at the distal end of the cannula, which facilitates the removal of any kinked guidewire.

[0031] In another preferred embodiment of the system, the mandrel, and the cannula, the tip is preferably made of a soft material (e.g., silicon), which additionally supports the guidance of the cannula and reduces the risk of damage to the hollow organ due to the softness of the tip.

[0032] In another preferred embodiment of the system, mandrel, and sleeve, the end includes a fastening device, particularly a thread, adapted to connect the end to the distal end of an elongated member. This has the advantage that the end can be manufactured as a separate component and thus can be mass-produced cost-effectively. Furthermore, different materials for the end can be quickly and easily replaced or supplied for specific applications.

[0033] In a preferred embodiment of the system, including the mandrel and the cannula, the head element is tapered, particularly tapered. By tapering, beveling, or tapering the head element, the distal end of the cannula has a streamlined outer profile, making it less likely for the cannula to become stuck or snagged during insertion, thus reducing the risk of injury when inserting the cannula into the corresponding hollow organ.

[0034] The system according to any one of the preceding claims, wherein the head element includes a first tapering region and a second tapering region. Advantageously, this allows the distal end of the cannula to adapt particularly advantageously to the end of the spindle, enabling a substantially smooth transition between the outer surface of the cannula and the surface of the distal end, and thereby reducing the risk of injury when the cannula is inserted into the corresponding hollow organ.

[0035] In a preferred embodiment of the system, including the mandrel and the sleeve, the first tapering region tapers to fit the surface of the distal sleeve body portion. Specifically, the first tapering region can be shaped to receive flexible filaments, i.e., the braid of the sleeve (which partially forms the outer skin of the sleeve), because, for example, due to the elasticity of the wires, a certain gentler angle of curvature allows the braid to attach better to the first tapering region compared to a steeper angle of curvature. To further facilitate better attachment of the wire mesh to the first tapering region, the first tapering region can, for example, be roughened, or include a wavy surface, or have certain attachment elements, such as knobs, to engage the wire filaments between the knobs.

[0036] In a preferred embodiment of the system, including the mandrel and the sleeve, the second tapering region tapers to accommodate the surface of the end. That is, a certain steep curvature angle allows for a smoother transition from the second tapering region of the head element to the surface of the end of the mandrel. This allows for a specific streamlined shape at the distal end of the sleeve when the mandrel is inserted into the sleeve and the sleeve is tensioned.

[0037] In a preferred embodiment of the system, mandrel, and sleeve, the opening of the head element includes a first diameter (R1) configured to receive the end and a second diameter (R2) configured to clamp the distal end of the elongated member. In this preferred embodiment, the end may include a diameter smaller than the distal end of the elongated member. For example, the end includes a diameter R1, and the distal end of the mandrel includes a diameter R2 for clamping. In this configuration, the end is fitted through the opening, and the elongated member abuts against the opening, allowing the mandrel to be tensioned. The end may include a soft material, such as silicon. Alternatively, the end may include a first segment and a second segment, the first segment including a diameter R1 for fitting through the opening, and the second segment including a diameter R2 configured not to fit through the opening, i.e., abutting against the opening, allowing the mandrel to be tensioned. The end may include a soft material, such as silicon.

[0038] In a preferred embodiment of the system, including the mandrel and the cannula, the cannula includes a venting opening adapted to compensate for pressure differentials, allowing fluid communication between the interior of the proximal cannula portion and the exterior of the cannula. This advantageously allows air trapped within the drainage circuit to escape. The venting opening includes, for example, orifices, channels, or any opening that allows fluid flow for ventilation.

[0039] In a preferred embodiment of the system, mandrel, and cannula, the vent opening includes a notch and / or slit disposed in the surface of the plug, and / or wherein the vent opening includes a vent passage disposed in the plug. In this case, for example, the slit is located on the surface of the plug, wherein the plug includes a first portion and a second portion, the first portion being inserted into the proximal end of the cannula body to tighten the cannula, and the second portion protruding from the proximal end of the cannula when the cannula is tightened. The slit then extends at least partially from the first portion into the second portion of the plug to allow fluid to escape from the lumen of the cannula. The slit is located in the surface of the plug, the surface of the plug forming surface contact with the surface of the cannula (i.e., with the proximal end of the cannula), wherein the plug seals the lumen of the cannula at the proximal end of the cannula in a fluid-impermeable manner.

[0040] Alternatively, channels (e.g., through-holes) are arranged in the plug so that fluid from inside the sleeve lumen can exit the lumen through the channels. The through-holes can be configured as straight or curved holes penetrating the plug. The through-holes may additionally include a filter material that selectively allows only a certain type of fluid to escape, such as allowing only gaseous fluids to escape, while any liquid remains inside the lumen. Alternatively, the filter material can act as a semi-permeable membrane, allowing only gaseous fluids to escape, while any liquid remains inside the lumen.

[0041] In a preferred embodiment of the system, including the mandrel and the cannula, the venting opening includes the proximal end of an elongated member, wherein the elongated member is tubular in shape to allow ventilation through it. In this embodiment, the elongated member can perform two tasks simultaneously. On the one hand, the guidewire can be advanced or de-escalated through the cannula by the tubular elongated member; on the other hand, fluid can flow through the hollow elongated member, particularly during guidewire removal.

[0042] In a preferred embodiment of the system, mandrel, and sleeve, the vent opening comprises a plurality of holes arranged in the elongated member. In this case, the holes include openings, particularly small openings, that allow gaseous liquid, in particular, to flow in or out through the holes. For this purpose, the proximal end of the elongated member includes, in particular, one or more holes through which gas in the lumen can flow out via the elongated member. The cavity of the tubular elongated member can be incorporated into the opening of the plug and / or the elongated member can be closed with the proximal end of the plug, allowing gaseous liquid to flow directly out from the elongated member.

[0043] In a preferred embodiment of the system, including the mandrel and the sleeve, the plug comprises a filter material, particularly sintered polytetrafluoroethylene (PTFE), to compensate for pressure differentials, allowing fluid communication between the interior of the proximal sleeve portion and the exterior of the sleeve. The filter material has the property of selectively blocking liquid fluids and being transparent to gaseous fluids. The plug can alternatively be made entirely of this type of material.

[0044] In a preferred embodiment of the system, including the mandrel and the cannula, the plug comprises a first segment and a second segment, wherein the second segment at least partially engages with the proximal cannula portion and includes a proximal end of an elongated member, and is at least partially tapered and / or cylindrical in shape. An advantage of this embodiment is that the particular tapered shape of the plug blocks the plug at the proximal end of the cannula, such that when the cannula is tensioned by pressing the plug into the proximal end of the cannula like a cork, the plug remains therein for at least a period of time, and thus the tension of the cannula is automatically maintained during this period. Attached Figure Description

[0045] Figure 1 A cross-sectional view of a system according to one embodiment is shown, the system including a cannula and a mandrel, wherein the cannula is in a normal configuration and wherein the mandrel is partially inserted into the lumen of the cannula body.

[0046] Figure 2a , 2b Both figures show a cross-sectional view of the distal end of a mandrel according to one embodiment, which includes a distal end and an elongated member, wherein the distal end is disposed at the distal end of the elongated member. Additionally, a guidewire is inserted into the mandrel.

[0047] Figure 3An enlarged view of the distal end of a system according to one embodiment is shown, which includes a cannula and a mandrel according to one embodiment.

[0048] Figure 4 A cross-sectional view of the head element according to one embodiment of the sleeve is shown.

[0049] Figure 5 A cross-sectional view of the distal end of a system according to one embodiment is shown, which includes a cannula and mandrel in a low-profile configuration, while a guidewire is shown separately.

[0050] Figure 6 An alternative cross-sectional view of the distal end of a system according to one embodiment is shown, which includes a cannula and a mandrel in a low-profile configuration, particularly for intravenous use.

[0051] Figure 7 A cross-sectional view of the proximal end of a system according to one embodiment is shown, which includes a cannula and a mandrel, wherein the plug includes a ventilation channel.

[0052] Figure 8 A cross-sectional view of the proximal end of a system according to one embodiment is shown, which includes a sleeve and a mandrel, wherein the elongated member is hollow and the plug includes multiple ventilation channels.

[0053] Figure 9 A cross-sectional view of the proximal end of a system according to one embodiment is shown, which includes a sleeve and a mandrel, wherein the elongated member is hollow in shape and further includes a plurality of holes.

[0054] exist Figure 1The image shows a cross-sectional view of a system according to one embodiment, comprising a cannula 1 and a mandrel 10, wherein the cannula 1 is in a normal configuration, and wherein the mandrel 10 is partially inserted into the lumen of the cannula body. The cannula body includes a distal cannula portion 2 and a proximal cannula portion 3, wherein the proximal cannula portion 3 includes a sleeve 3 to which a plurality of flexible filaments 4 are attached, forming a flexible body portion of the cannula 1. The distal cannula portion 2 includes a head element 11 forming the end of the cannula, and the flexible filaments 4 are attached distally to the head element. The mandrel 10 includes a plug 6, an elongated member 7 having a distal end 8 and a proximal end 9, and an end 5. The plug 6 is connected to the proximal end 9 of the elongated member, and the end 5 is connected to the distal end 8 of the elongated member. The plug is fitted tightly with its second section 24 into the sleeve 3 forming the proximal cannula portion 3, thereby sealing the interior of the proximal cannula portion 3 in a fluid-impermeable manner. The first segment 23 of the plug remains outside the proximal cannula portion 3. The plug further includes a notch 19 disposed in the surface 20 of the plug. The notch 19 extends from the second segment 24 of the plug to the first segment 23 of the plug so as to allow airflow of fluid (e.g., gas) located inside the cannula 1 once other fluid (e.g., blood) has been drained through the cannula 1, and this fluid is forced to the outside of the cannula 1 through the notch 19. Thus, in particular, air located inside the cannula 1 is released through the notch before blood is drained.

[0055] The distal end 5 is configured to extend partially through the opening 12 of the head element 11, thereby at least partially forming the end of the cannula. Therefore, when the mandrel 10 is pulled out of the cannula 1, causing the cannula to change from a low-profile configuration to a normal-profile configuration, a larger opening 12 is retained at the end of the cannula 1 compared to the prior art. This advantageously allows the guidewire 25 more degrees of freedom of movement and thus facilitates removal of the guidewire 25 from the cannula 1. The guidewire 25 is inserted into the plug 6 through the guidewire insertion opening 26. The elongated member 7 of the mandrel 10 is tubular to allow the guidewire 25 to extend through the mandrel 10 and the cannula 1 for guiding the cannula 1 inside a hollow organ (e.g., a vein).

[0056] Figure 2a , Figure 2b The distal end of the mandrel 10 according to one embodiment is shown in cross-sectional view, including a distal end 5 and an elongated member 7, wherein the distal end 5 is disposed at the distal end of the elongated member 7. Additionally, a guide wire 25 is inserted into the mandrel 10 and extends through the mandrel 10. Figure 2aIn the embodiment, end 5 includes a fastening device 13, such as a thread, for connecting end 5 to the distal end 8 of the elongated member. End 5 is particularly symmetrically attached to the elongated member 7, preferably the elongated member being cylindrical and tubular, and preferably end 5 being cylindrical, with a diameter smaller than that of the elongated member 7, thereby retaining a clamping region 27. The clamping region 27 serves to provide surface areas 27 of corresponding surfaces on adjacent joint element 11, allowing tension to be established to tension the mandrel 10 within the sleeve 1, thereby converting the sleeve 1 from a normal profile to a low profile configuration. In an alternative embodiment, end 5 includes a clamping region 27. In this embodiment, the end extends to Figure 2a The dashed line shown indicates the location where the distal end and end 5 of the elongated member 7 are connected to each other, in particular, by means of a fastening device (e.g., thread 13).

[0057] Figure 2b Another alternative embodiment is shown, in which end 5 is shown as a distal end 8 of a tapered shape attached to an elongated member 7. A guide wire 25 extends through the elongated member 7 and end 5. In this embodiment, a clamping region 27 is formed by a tapered (i.e., particularly tapered) region of the elongated member 7. Preferably, end 5 and / or the elongated member 7 are tubular and are substantially cylindrical and / or at least partially tapered. End 5 includes a fastening device 13 for connection to the distal end of the elongated member 8, the fastening device being, for example, a thread. In another alternative embodiment, the end includes a clamping region 27, and thus the end extends to... Figure 2b The dotted lines are shown in the diagram. In this case, the thread 13 extends further beyond the clamping region 27 to connect to the distal end 8 of the elongated member.

[0058] exist Figure 2a , Figure 2b In the cannula, the distal end 6 may include some flexible, soft material, such as silicon, which softens and makes the distal end more flexible. Because the distal end of the cannula is at least partially softer and more flexible, the risk of injury is lower during insertion of the cannula 1 into the hollow organ.

[0059] Figure 3An enlarged view of an embodiment of the system's distal end is shown, comprising a cannula 1 and a mandrel 10. The figure specifically illustrates how a clamping region 27 engages with a head element 11 to tension the mandrel 10 within the cannula 1. A guide wire 25 extends through the mandrel 10. The head element 11 includes a first tapered region 14 configured to attach to a surface 16 formed by a plurality of flexible elements 4 on the distal cannula body portion. The plurality of flexible filaments 4 form a wire mesh. To better attach the wire mesh to the tapered region 14 of the head element, the region 14 may be roughened, or include a corrugated surface, or include attachment elements, such as knobs, to engage the wire filaments between the knobs. The head element 11 further includes a second tapered region 15.

[0060] Figure 4 A cross-sectional view of a head element 11 according to one embodiment of the sleeve 1 is shown. The head element 11 includes a first opening 12 with radius R1 and a second opening 12 with radius R2, wherein, in Figure 4 In the embodiment shown, R1 is greater than R2. Alternatively, R1 can be equal to R2 and / or R1 can be less than R2. Figure 4 In the embodiment shown, R1 is greater than R2, which creates a clamping region 27. A clamping region 27' is created when R1 is equal to R2 or when R1 is less than R2. Figure 4 In the illustrated case, the distal end 8 of the elongated member extends partially into the opening 12 until the distal end 8 of the elongated member reaches and abuts against the clamping region 27. However, the end 5 attached to the elongated member 7 extends through the opening 12, i.e., the end 5 extends through the opening segments with radii R1 and R2. Therefore, R2 is configured to be large enough that the end 5 extends through the head element 11. In one embodiment, when the end includes the clamping region 27, the end extends partially through the opening 12 such that the clamping region 27 is clamped within the opening 12. In this alternative case, the end 5 extends partially through the segment with radius R1 and extends through the segment with diameter R2. The head element is preferably formed at least partially in a cylindrical shape and / or partially in a tapered shape along an axis of symmetry A, which is located at... Figure 4 The area is shown as a dashed line. The head element 11 includes a first tapered region 14 and a second tapered region 15, wherein, preferably, a step 28 appears between the first tapered region 14 and the second tapered region 15. The step 28 is configured to be large enough that when the flexible filament 4 is attached to the first tapered region 14, a smooth transition occurs between the second tapered region 15 and the surface of the sleeve 1 (i.e., the surface formed by the plurality of flexible filaments 4 (i.e., wire mesh)).

[0061] Figure 5A cross-sectional view of the distal end of a system according to one embodiment is shown, comprising a cannula 1 and a mandrel 10 in a low-profile configuration. The feature of interest in this figure is that a head element 11, having a first taper 14 and a second taper 15, is adapted to form a streamlined outer cannula 1 surface, facilitating guidance of the cannula 1 through the hollow organ along the guidewire 25. Thus, the first taper 14 of the head element 11 tapers, resulting in a smooth transition from the flexible filament 4 to the head element 11. Furthermore, the second taper 15 of the head element 11 is adapted to substantially align with the end 5 of the mandrel (i.e., the portion of the end 5 extending through the opening 12 of the head element 11), thereby forming the end of the cannula 1. Figure 5 In the illustrated embodiment, the sleeve 1 is in a low-profile configuration. The distal end 8 of the elongated member abuts against the clamping region 27'. In this embodiment, the radii R1 and R2 of the opening 12 of the head element 11 are equal, such that the end extends through the opening.

[0062] Figure 6 A cross-sectional view of the distal end of a system according to one embodiment is shown, comprising a cannula 1 and a spindle 10 in a low-profile configuration, particularly for intravenous use. In this embodiment, fluid (e.g., blood) can flow bidirectionally, i.e., into and out of the cannula 1, as indicated by the arrows. To reduce or prevent eddy formation and / or inappropriate pressure distribution in the outflowing fluid, particularly for medical applications, the head element 11 includes an extended bend 29. The extended bend 29 is adapted to allow fluid to flow substantially laminarly within the cannula 1. In this particular embodiment, the opening of the head element includes a plurality of radii Ri, which are configured such that the distal end 5 extends at least partially through the head element 11, as shown below. Figure 6 As shown. The distal end 8 of the elongated member includes a clamping region 27". Figure 2a , Figure 2b The different types of embodiments of end 5 shown are also applicable. Figure 6 In the embodiment, the clamping area 27 is as follows Figure 2b The tapering shown preferably coincides with the bending region, thereby creating an extended clamping surface 27". That is, the clamping surface 27” extends over several radii Ri of the extended bending region.

[0063] Figure 7A cross-sectional view of the proximal end of a system according to one embodiment is shown, comprising a cannula 1 and a mandrel 10, wherein the plug 6 includes venting channels 18 and 21. Venting channel 21 allows fluid (particularly a gaseous fluid, such as air) to be released through channel 21 prior to drainage. The plug 6 is preferably formed in a cylindrical and / or tapered shape, having a first segment 23 and a second segment 25, the second segment 25 being fitted tightly into the proximal cannula portion 3 to seal the proximal cannula portion 3 in a fluid-impermeable manner. The plug further includes an opening such that the proximal end 9 of the elongated member can be connected to the plug, and the plug further includes a guidewire insertion opening 26, in which… Figure 7 In the illustrated embodiment, the guidewire insertion opening further serves as a venting opening 18, allowing fluid communication between the interior of the cannula 1 and the exterior of the cannula. Therefore, the venting opening 18 includes a venting channel 21 and a guidewire insertion opening 26. Fluid flow released through the venting opening 18 is... Figure 7 The arrow in the text indicates this.

[0064] Figure 8 Another embodiment of the ventilation opening 18 is shown. In this embodiment, with Figure 7 The embodiment shown is similar, with the plug including a guide wire insertion opening 26 serving as a venting opening and a plurality of channels 21 arranged in the second segment 24 of the plug. Figure 8 As shown, the second segment 24 of the plug tapers and fits snugly into the proximal sleeve portion 3. The elongated member 7 is tubular in shape to engage the guidewire 25 (not shown), but also allows fluid to pass through the elongated member 7 for venting. Thus, the vent opening 18 includes the guidewire insertion opening 26, the channel 21, and at least the distal portion 9 of the hollow elongated member. Fluid flow for releasing the pressure difference between the inside and outside of the sleeve 1 is provided by... Figure 8 The arrow in the diagram indicates that channel 21 is shown vertically relative to the elongated member 7; however, any other arrangement of the channel relative to the elongated member (e.g., diagonal arrangement) is also possible, as long as the interior of the sleeve 1 is in fluid communication with the exterior of the sleeve 1, such as the guide wire insertion opening 26 of the sleeve. Figure 8 In the image, the arrow indicates the direction of airflow through sleeve 1.

[0065] Figure 9 Another embodiment of the ventilation opening 18 is shown. In this embodiment, with Figure 7 , Figure 8 Similar to the embodiment shown, the plug includes a guide wire insertion opening 26 serving as a vent opening 18 and a plurality of holes 22. The holes 22 are arranged at the proximal end 9 of the elongated member 7, which is tubular in shape, allowing fluid inside the sleeve 1 to flow through the holes 22 into at least the proximal end 9 of the elongated member, thus allowing pressure release of the fluid. Therefore, in Figure 9In the illustrated embodiment, the venting opening 18 includes a proximal end 9 of a tubular elongated member, a guidewire insertion opening 26, and a hole 22 disposed at the proximal end 9 of the elongated member. Alternatively, the elongated member 7 may be tubular, allowing the guidewire 25 to be fully inserted through it. Specifically, after the guidewire is withdrawn, fluid can enter the proximal end 9 of the elongated member through the hole to ventilate the fluid. Figure 9 In the image, the arrow indicates the direction of airflow through sleeve 1.

[0066] List of reference numerals

[0067] 1. Sleeve

[0068] 2. Distal sleeve section

[0069] 3. Proximal cannula section

[0070] 4 Flexible filaments

[0071] 5. End

[0072] 6. Plug

[0073] 7 Slender components

[0074] 8. The distal end of a slender member

[0075] 9. Proximal end of slender member

[0076] 10 mandrels

[0077] 11 Head components

[0078] 12. Opening of the head component

[0079] 13 Fastening devices

[0080] 14. First tapered section of the head component

[0081] 15. Second tapered section of the head component

[0082] 16. Surface of the distal casing body

[0083] 17. Surface at the end

[0084] 18 Ventilation opening

[0085] 19 Notch

[0086] 20. Surface of the plug

[0087] 21 Ventilation Channel

[0088] 22 holes

[0089] 23 The first part of the plug

[0090] 24. The second part of the plug

[0091] 25 guidewire

[0092] 26. Guide wire insertion opening

[0093] 27", 27', 27" clamping area

[0094] 28 steps

[0095] 29. Extension bending area of ​​head component

Claims

1. A system for vascular drainage, the system comprising a cannula (1), particularly a cannula for use in medical applications, the cannula having a distal cannula portion (2) and a proximal cannula portion (3), wherein, The sleeve includes Multiple flexible filaments (4) allow the sleeve to vary between a normal profile configuration and a low profile configuration, and The mandrel (10) comprises an end (5), a plug (6), and an elongated member (7), wherein the elongated member (7) includes an end (5) at its distal end (8) and a plug (6) at its proximal end (9) to form a mandrel (10), wherein the plug (6) is configured to be at least partially movably positioned within the proximal cannula portion (3), and A head element (11) is disposed at the distal cannula portion (2), wherein the head element (11) includes an opening (12) configured to partially receive the distal end (8) of the mandrel, such that the positioning of the plug (6) at the proximal cannula portion (3) causes the cannula to vary between a normal profile configuration and a low profile configuration.

2. The system according to claim 1, wherein, The end (5) is configured to extend partially through the opening (12) such that the end (5) supports guiding the cannula (1) through the blood vessel.

3. The system according to any one of the preceding claims, wherein, The end (5) includes a fastening device (13), in particular a thread, which is adapted to connect the top end (5) to the distal end of the elongated member (7).

4. The system according to any one of the preceding claims, wherein, The head element (11) tapers, and is in particular tapered in shape.

5. The system according to any one of the preceding claims, wherein, The head element (11) includes a first tapered region (14) and a second tapered region (15), wherein, in particular, the second tapered region (15) tapers to fit the surface (17) of the end. or The head element (11) includes a first tapered region (14) and a second tapered region (15), wherein the first tapered region (14) tapes to fit the surface (16) of the distal cannula body portion, and wherein, in particular, the second tapered region (15) tapes to fit the surface (17) of the end portion.

6. The system according to any one of the preceding claims, wherein, The opening (12) of the head element (11) includes a first diameter (R1) configured to receive the end (5) and a second diameter (R2) configured to clamp the distal end of the elongated member (7).

7. The system according to any one of the preceding claims, wherein, The sleeve (1) includes a vent opening (18) adapted to compensate for pressure differential, such that the interior of the proximal sleeve portion (3) is in fluid communication with the exterior of the sleeve (1).

8. The system according to claim 7, wherein, The vent opening (18) includes a recess (19) disposed in the surface (20) of the plug, and / or wherein the vent opening (18) includes a vent passage (21) disposed in the plug.

9. The system according to claim 7 or 8, wherein, The ventilation opening (18) includes the proximal end (9) of the elongated member, wherein the elongated element (7) is tubular to allow ventilation through the elongated member (7).

10. The system according to claim 9, wherein, The ventilation opening (18) includes a plurality of holes (22) arranged in the elongated member (7).

11. The system according to any one of claims, wherein, The plug (6) includes a filter material, particularly sintered polytetrafluoroethylene, to compensate for pressure differentials, thereby allowing the interior of the proximal sleeve portion (3) to be in fluid communication with the exterior of the sleeve (1).

12. The system according to any one of claims, wherein, The plug (6) includes a first segment (23) and a second segment (24), wherein the second segment (24) is at least partially engaged in the proximal sleeve portion (3) and includes the proximal end (9) of the elongated member, and is at least partially tapered and / or cylindrical in shape.

13. Parts kit, including A cannula (1), particularly a cannula for use in medical applications, the cannula having: a distal cannula portion (2) and a proximal cannula portion (3), wherein, The sleeve (1) includes a plurality of flexible filaments (4) such that the sleeve (1) can vary between a normal profile configuration and a low profile configuration; and a head element (11) disposed at the distal sleeve portion (2), wherein the head element (11) includes an opening (12). A mandrel (10) comprising an end (5), a plug (6), and an elongated member (7), wherein the elongated member (7) comprises an end (5) at its distal end (8) and a plug (6) at its proximal end (9) to form the mandrel (10), wherein the plug (6) is configured to be at least partially movably positioned within the proximal cannula portion (3), and The opening (12) of the head element (11) is configured to partially receive the distal end (8) of the mandrel, such that the positioning of the plug (6) at the proximal cannula portion (3) causes the cannula to vary between the normal profile configuration and the low profile configuration.

14. A cannula, particularly for use in medical applications, said cannula having a distal cannula portion (2) and a proximal cannula portion (3), wherein, The sleeve includes Multiple flexible filaments (4) allow the sleeve to vary between a normal profile configuration and a low profile configuration; and a head element (11) disposed at the distal sleeve portion (2), wherein the head element (11) includes an opening (12), wherein the opening of the head element includes a first diameter (R1) and a second diameter (R2).

15. A mandrel for use in a cannula having a distal cannula portion and a proximal cannula portion and a plurality of flexible filaments (4), said mandrel comprising an end (5), a plug (6), and an elongated member (7), wherein, The elongated member (7) includes an end (5) at its distal end (8) and a plug (6) at its proximal end (9) to form a mandrel (10), wherein the plug (6) is configured to be at least partially movably positioned in the proximal cannula portion (3).

Images