Drainage system

Abstract

A system for venous drainage, comprising a cannula for use in medical applications, wherein the cannula comprises a plurality of flexible filaments so that the cannula can change between a normal contour configuration and a low contour configuration, and the proximal cannula portion comprises a cannula formed by a sleeve, and a plug device comprising first and second sections, the second section being configured to be releasably positioned within the sleeve, and the plug device comprising at least one fastening member configured to establish an press-fit connection and / or a torsion connection and / or a clamp connection between the sleeve and the plug device, such that when the plug device engages with the sleeve, the cannula transitions from a normal contour configuration to a low contour configuration.

Description

【Background Art】 【0001】 For draining blood towards a life support device prior to reinjection into the circulation, cannulation is essential for extracorporeal circulation. In high-flow applications such as cardiopulmonary bypass, extracorporeal membrane oxygenation, etc., the cannula is typically the narrowest part in the perfusion circuit, so the performance of the cannula can be very important. Conventional cannula designs are typically based on a straight-line design, i.e., a straight tube. As a result, the resistance of such a cannula increases linearly with the length of the cannula. Therefore, a shorter cannula can provide better performance. However, in the case of a venous cannula, the tip of the cannula must be positioned in the right atrium to avoid occlusion of the cannula opening, which can cause additional complications. 【0002】 As a result, two approaches have been developed to improve venous drainage. One approach involves making the cannula wall thinner to increase the cross-sectional area, thereby providing lower resistance. Another approach involves the use of enhanced venous drainage achieved through a centrifugal pump or vacuum. However, the latter approach requires an increase in suction, which can result in occlusion of the cannula opening and interruption of venous drainage. This phenomenon is a typical finding in clinical cases undergoing minimally invasive heart surgery with remote cannulation. 【0003】 To overcome this problem, European Patent No. 1248571 or European Patent No. 2341850 describes a cannula for venous drainage having a small diameter solely for insertion into a blood vessel. The cannula comprises a cannula body having a lumen extending between the proximal and distal ends of the cannula, and the cannula is formed from a flexible material and has at least one mechanism that, when activated, changes the structure of the cannula between a normal contour structure having a predetermined large lumen diameter for venous drainage and a low contour structure that reduces the lumen diameter of the cannula for insertion into the patient's blood vessel. Thus, the cannula has a watertight coating at the proximal end, and the flexible material, such as a series of interwoven or woven wires, is coated at the proximal end, while blood flow occurs through the uncoated interwoven wires at the distal end of the cannula. After properly positioning the cannula in the blood vessel, the distal end of the cannula is expanded from a low-profile configuration to a normal-profile configuration, that is, to the surface of the inner wall of the blood vessel for drainage. 【0004】 To switch the cannula to a low-profile configuration for insertion into the patient's blood vessel, i.e., to extend the flexible wire mesh of the cannula body, a mandrel may be inserted into the lumen of the cannula, i.e., covering the guidewire from the proximal end to the distal end of the cannula. The mandrel comprises an elongated member and a plug. The elongated member has a distal end and a proximal end. The plug is positioned at the proximal end of the mandrel, i.e., the plug forms the proximal end of the mandrel. When inserted into the lumen of the cannula, the elongated member abuts the tip of the cannula at its distal end. At the proximal end, the plug may be inserted into the proximal end of the cannula, but the proximal end of the cannula is formed by a sleeve. Because the lengths of the cannula and the mandrel are different, when a force is applied to the plug, for example when the plug is pushed further into the opening of the cannula, i.e., further into the sleeve, tension is applied to the cannula. The force applied to the plug creates tension in the wire mesh, shifting the cannula into a desirable low-profile configuration for insertion into a hollow organ. In the low-profile configuration, the cannula has a predetermined diameter, i.e., the lumen of the cannula has a smaller diameter than in the normal-profile configuration where the lumen has a larger diameter. 【0005】 The wire mesh is attached to the distal end component of the cannula and to the sleeve at the proximal end of the cannula. Thus, the sleeve essentially forms the proximal end of the cannula. 【0006】 During the initial stages of drainage and while the mandrel extends the cannula, i.e., while the cannula is in a low-profile configuration, the large opening formed by the wire mesh inside the cannula is blocked by the surface of the elongated member of the mandrel, so that fluid, such as blood from the patient, cannot pass through the inside of the cannula. Therefore, the plug must maintain its fastening position during insertion. To transition the cannula to a normal-profile configuration, i.e., when fluid or blood flows through the opening of the cannula, the plug must be removed from its fastening position, preferably in a stepwise manner. 【0007】 Accordingly, in European Patent No. 2341850, the plug is tightly fitted to the proximal cannula portion, i.e., the sleeve, or alternatively, a locking mechanism is described in Figures 12A to 12C of European Patent No. 2341850. To establish a blind fit or press-fit connection between the plug and the sleeve, the plug has a slight taper or is conical in shape, and the connection is maintained by frictional force. These forces arise when the inner diameter of the sleeve is slightly larger than the outer dimensions of the plug area, and the plug is fitted into the sleeve. Preferably, to increase friction, the sleeve is formed from an elastic material such as silicon. Blind fit connections have the disadvantage that the frictional force may be reduced and the connection may become uncontrolled and relaxed, for example, due to liquid from cleaning the mandrel before use. Furthermore, temperature affects the elasticity of the material of the cannula sleeve, which affects the frictional force, and can also lead to uncontrolled relaxation of the connection. 【0008】 The alternative locking mechanism described in European Patent No. 2341850 uses a connector with several re-hooks that are inserted into the proximal cannula and configured to engage with a clamp. The clamp has an elongated member, which thus engages with one of the re-hooks, thereby applying tension to the cannula. The locking mechanism has the disadvantage of requiring a separate connector. Furthermore, it must be monitored during manufacturing that the connector is connected to the proximal cannula in a manner that can withstand the mechanical traction required to apply tension to the cannula. Therefore, the described locking mechanism is more expensive. 【0009】 Accordingly, an object of the present invention is to provide an alternative solution that overcomes the aforementioned drawbacks to the problem of positioning the plug in a releasable manner at the proximal cannula portion in order to reversibly transition the cannula from a normal contour configuration to a low-contour configuration. In particular, it is possible to gradually apply tension to the cannula and release it while keeping the cannula tight against blood loss. [Overview of the project] 【0010】 The problem is solved by the subject matter of the independent claims, namely the system for venous drainage according to claim 1, the plug device according to claim 11, the support sleeve according to claim 12, the cannula according to claim 14, and the kit of components according to claim 15. Further preferred embodiments of the present invention are the subject matter of the dependent claims. 【0011】 The venous drainage system according to the present invention is a cannula having a distal cannula portion and a proximal cannula portion, particularly for use in medical applications, wherein the cannula comprises a plurality of flexible filaments so that the cannula can change between a normal contour configuration and a low contour configuration, the proximal cannula portion comprises a cannula formed by a sleeve and a plug device having first and second sections, the second section being configured to be releasably positioned within the sleeve, and the second section having an opening for receiving the proximal portion of an elongated member, wherein the plug device comprises at least one fastening member configured to establish a press-fit connection and / or a torsion connection and / or a clamp connection between the sleeve and the plug device so that the cannula transitions from a normal contour configuration to a low contour configuration when the plug device engages with the sleeve. 【0012】 Drainage is a medical procedure. Drainage is used to remove or aspirate pathological or excess bodily fluids or gases in order to restore a normal state. In principle, a distinction is made between internal and external drainage. In internal drainage, obstructions are surgically bypassed, for example, with minimally invasive surgery, or accumulated fluids are drained into hollow organs, such as the stomach or intestines. In external drainage, fluids are drained from the inside of the body to the outside. 【0013】 For example, a venous drainage system using the Seldinger method typically includes a guidewire that is inserted into the patient's blood vessel before drainage and serves to guide the cannula into a hollow organ, which is, in principle, a flexible hollow tube through which the fluid to be drained is directed to the outside of the blood vessel, i.e., out of the patient. 【0014】 Cannulas are designed to be inserted into hollow organs, which may be selected from, for example, veins, arteries, urethras, ureters, intestines, esophagus, trachea, bronchi, pleural cavity, and / or peritoneum. 【0015】 The use of cannulas in medical settings includes methods such as positioning the cannula in a low-profile configuration, inserting the cannula into the patient's hollow organ at the insertion point, and returning the cannula to a normal-profile configuration. In the normal-profile configuration, the cannula expands, particularly at the distal end, i.e., distal to the insertion point, to the diameter of the hollow organ or to the maximum diameter of the cannula body, i.e., the lumen of the cannula formed by the cannula body. 【0016】 In a low-profile cannula configuration, the diameter of the cannula is reduced compared to a standard-profile configuration in order to insert the cannula into a hollow organ, such as a blood vessel. In a low-profile configuration, the wire mesh, i.e., the flexible filaments of the cannula, forms the cannula body and thereby defines the lumen of the cannula. In a low-profile configuration, the flexible filaments are inherently under tension compared to a standard-profile configuration. The diameter of the cannula 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 is a multiple diameter that arises in a standard-profile configuration from the actual shape of the cannula body and / or lumen, but changes when tension is applied to the cannula in a low-profile configuration. 【0017】 When a cannula is in a normal contoured configuration during use, the diameter of the lumen distal to the insertion point varies in relation to the diameter of the surrounding vessel. Furthermore, when a cannula is in a normal contoured configuration during use, a portion of the cannula distal to the insertion point supports the inner surface of the surrounding vessel. When a cannula is in a low-contour configuration, a portion of the cannula is characterized by a narrower lumen diameter, which is appropriate for insertion into the target of the cannula and smaller access vessels. However, the placement of the cannula in a low-contour configuration may be done before, during, or after cannula insertion. 【0018】 To allow for a change in the diameter of the cannula, the cannula comprises a flexible filament, i.e., an elastic body formed from at least partially flexible filaments. The multiple flexible filaments may include 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, flattened, triangular, rectangular, and combinations thereof. In one embodiment, the multiple flexible filaments are textile fibers. The multiple flexible filaments may be assembled together, knitted together, or woven together. Alternatively, the multiple flexible filaments are interwoven. 【0019】 The elastic filament is defined as the inner lumen of the cannula, encompassing a volume whose spatial range can vary due to the elastic filament. The lumen has a distal end that points toward the insertion point and a proximal end that points toward the opposite direction from the insertion point, i.e., away from the patient. As a result, the cannula comprises a distal cannula portion, which is the part closer to the insertion point, and a proximal cannula portion, which is the part further away from the insertion point. 【0020】 To change the spatial range of the cannula lumen, that is, to apply tension to the cannula by changing its structure from a normal contour configuration to a low-contour configuration, the mandrel is inserted into the lumen from the proximal to the distal cannula. The mandrel comprises an elongated member and a plug. The elongated member has a distal end and a proximal end, and the plug is positioned at the proximal end of the elongated member. To enable the cannula diameter or the cannula lumen to change between a low-contour configuration and a normal contour configuration, the mandrel, i.e., the plug with the connected elongated member, is inserted into the cannula lumen such that the distal end of the elongated member engages with the distal portion of the cannula. The plug is then further pushed into the cannula lumen, i.e., the proximal portion of the cannula. This applies tension to the flexible filament of the cannula, thereby creating a force that changes the cannula diameter from a normal contour configuration to a low-contour configuration. When the mandrel is removed, the cannula expands to its unclamped diameter, particularly due to the tendency of the flexible filament to take on an initial, spring-like normal shape, although the normal shape relates to the larger diameter of the lumen at the insertion point. The elongated member of the mandrel may have a hollow tube, especially for medical applications, and may be configured for inserting a guidewire through the hollow tube. In this case, to further guide the cannula to the application site through a blood vessel, such as a vein, the guidewire passes through the elongated member to the distal end of the cannula and then through the hollow organ, such as a vein, from the distal end of the cannula. The guidewire may then be inserted into and removed from the hollow organ via the mandrel positioned inside the body of the cannula. Furthermore, the mandrel may be removed from the cannula, while the guidewire remains positioned inside the cannula and the hollow organ. 【0021】 The elongated member preferably comprises a hollow tube, and therefore the plug of the mandrel has an opening configured for inserting a guide wire. The plug is positioned at the proximal end of the mandrel, and the elongated member connects the plug to the distal end of the elongated member, thereby forming the mandrel. 【0022】 The cannula comprises a distal cannula portion and a proximal cannula portion, the proximal cannula portion being formed by a sleeve. The sleeve refers to, for example, a tube, particularly an elastic tube made of, for example, silicone, and functions to attach a flexible filament to the proximal end of the cannula so that a predetermined lumen diameter of the cannula is permanently present at the proximal end of the cannula, allowing the cannula to be connected to, for example, a cardiovascular machine. 【0023】 A plug device refers to a device configured to be partially inserted into the proximal cannula portion, i.e., the sleeve or support sleeve. In principle, a plug device is similar to a cork that is partially pressed into the neck of a bottle to seal it from the outside. Thus, the plug comprises first and second sections, the second section corresponding to the portion that is releasably inserted into the sleeve. The second section is inserted into the sleeve to apply tension to the cannula and released from the sleeve to release tension from the cannula. The first section may function to provide an application surface from which the plug device is withdrawn from the sleeve. The first section also mechanically supports the second section. The plug comprises at least one fastening element that can be positioned in the first and / or second sections. The plug device preferably further comprises an opening so that a guidewire can be inserted through the plug. 【0024】 The plug comprises at least one fastening member. The fastening member is configured to establish a press-fit connection and / or torsional connection and / or clamp connection between the sleeve and the plug device, such that when the plug device engages with the sleeve, the cannula transitions from a normal profile configuration to a low profile configuration. Thus, the fastening member relates to a member that can provide a press-fit connection and / or torsional connection and / or clamp connection in particular between the plug and the sleeve or support sleeve. For example, such a member may be a projection positioned on the surface of a second area. The surface of the second area is exposed to the inner surface of the sleeve or support sleeve so that adjacent surfaces are obtained. The mutual contact pressure of the adjacent surfaces forms, for example, a press-fit connection, in which case the projection supports the press-fit by increasing the frictional force, i.e., mutual contact pressure, between the inner surface of the sleeve or support sleeve and the surface of the second area. The projection can take on a wide variety of shapes, insofar as it increases the frictional force, i.e., mutual contact pressure, of the adjacent surfaces. 【0025】 Further examples of fastening members are screws or grooves. Screws can provide a rotational connection, or torsional connection, between the plug and the sleeve or support sleeve. Such rotational connections have the advantage that multiple different forces for applying tension to the cannula can be adjusted. Thus, the transition from a low-profile configuration to a normal-profile configuration can be carried out very carefully, depending on the screw pitch. 【0026】 Another example of a fastening member is a groove configured to receive a projection so that the projection is held within the groove when the cannula is in a low-profile configuration. The plug may have multiple grooves to achieve different holding positions in order to apply or release tension to the cannula in stages. 【0027】 Therefore, examples of fastening members may be screws, or rings, or grooves, or a combination thereof, or any combination thereof. A single fastening member may also comprise, for example, a combination of screws and / or protrusions and / or grooves, or any combination of a combination thereof. 【0028】 Press-fit connection relates here to a type of connection based, for example, on the connection pressure between two adjacent surfaces. Thus, when two adjacent surfaces, i.e., the mating parts, press against each other, in particular the frictional force or the adhesive force increases so that the two surfaces do not move relative to each other. Thus, press-fit, also known as interference fit or friction fit, is a fastening form between two precisely mating parts that creates a joint that is held together by friction after the parts have been pushed together. The strength of the fit is controlled by the amount of interference, which is the planned difference from the tolerance, i.e., the normal size. In this case, this may be the taper angle β of the second region of the plug, and / or the size of the protrusion, and / or the inner diameter of the sleeve or support sleeve into which the second region is inserted. 【0029】 Twist connection relates here to a type of connection that is essentially based on a rotational joint or rotational connection or rotational union, for example, by any type of connection between two interlocking screws, or a bayonet fastener, or between two components, such as a sleeve and a plug, and requires a rotational movement to close and / or open the connection. 【0030】 Clamp connection relates here to a type of connection based on a clamp between components, for example, a fastening member and a protrusion. A clamp connection is usually a detachable connection between two components. A frictional connection is created by a screw or spring that has been pre-tensioned during assembly. For example, a clamp connection may be provided by a clamp in the form of a pair of pliers, such as a laundry clip, for fixing laundry. 【0031】 The present invention also relates to a plug for use particularly in a medical cannula, wherein the cannula is formed by a sleeve, particularly a support sleeve, with a proximal cannula part and a plurality of flexible filaments such that the cannula can vary between a normal contour configuration and a low-profile configuration. The plug device comprises a first and a second region, and the second region is configured to be releasably positioned within the sleeve, particularly within the support sleeve, and has an opening for receiving the proximal part of an elongate member. The plug device is configured to establish a press-fit connection and / or a twist connection and / or a clamping connection between the sleeve, particularly the support sleeve, and the plug device such that when the plug device engages the sleeve, particularly the support sleeve, the cannula transitions from the normal contour configuration to the low-profile configuration, and the plug device comprises at least one fastening member for this purpose. 【0032】 The present invention also relates to a support sleeve forming a proximal cannula part for use particularly in a cannula for medical applications, wherein the cannula has a plurality of flexible filaments such that the cannula can vary between a normal contour configuration and a low-profile configuration. The support sleeve is configured to establish a press-fit connection and / or a twist connection and / or a clamping connection between the cannula and the plug device, particularly having male threads and / or protrusions and / or grooves. The cannula further comprises a sleeve forming the proximal cannula part such that the support sleeve is slid over and positioned on the sleeve, thereby forming the proximal cannula part. 【0033】 The present invention also relates to a cannula having a distal cannula part and a proximal cannula part for use particularly in medical applications, wherein the cannula has a plurality of flexible filaments such that the cannula can vary between a normal contour configuration and a low-profile configuration. The proximal cannula part is formed by a sleeve, particularly a support sleeve, and the sleeve, particularly the support sleeve, is configured to establish a press-fit connection and / or a twist connection and / or a clamping connection between the sleeve, particularly the support sleeve, and the plug device, particularly having male threads and / or protrusions and / or grooves. 【0034】 The present invention also relates to a kit of components comprising a cannula having a distal cannula portion and a proximal cannula portion, for use particularly in medical applications, wherein the cannula comprises a plurality of flexible filaments so that the cannula can change between a normal contour configuration and a low contour configuration, and the proximal cannula portion is formed by a sleeve, particularly by a support sleeve, and a plug device having first and second sections, wherein the second section is configured to be releasably positioned within the sleeve, particularly within the support sleeve, and has an opening for receiving the proximal portion of an elongated member, and the plug device comprises at least one fastening member configured to establish a press-fit connection and / or torsion connection and / or clamp connection between the sleeve, particularly the support sleeve and the plug device, such that when the plug device engages with the sleeve, particularly the support sleeve, the cannula transitions from a normal contour configuration to a low contour configuration. 【0035】 In a preferred embodiment of the system and cannula, the proximal cannula portion is formed by a support sleeve. The support sleeve is positioned at least partially over the sleeve at the proximal cannula portion, thereby forming the proximal cannula portion in place of the sleeve, but essentially having the same effect as an additional sleeve. The use of a support sleeve has the advantage that cannulas can be manufactured without determining the type of connection mechanism between the proximal cannula portion and the plug. This makes it possible to reduce manufacturing costs as support sleeves can be manufactured in large quantities in different types in advance. Different types of support sleeves include, for example, threads, protrusions, and / or grooves to establish press-fit and / or torsion and / or clamp connections between the cannula and the plug device. 【0036】 In preferred embodiments of the system and plug, particularly for press-fit connections, the fastening member comprises a ring-shaped or annular projection. In this preferred embodiment, the second section inserted into the sleeve or support sleeve comprises a ring-shaped or annular projection, or a plurality thereof. This allows for an advantageous increase in the contact pressure between the plug and the sleeve. Preferably, the ring-shaped or annular projections are positioned adjacent to each other in such a manner that the plug can be released in stages, for example, if there are three ring-shaped or annular projections, the plug can be pulled out to such an extent that the other two projections remain in the sleeve, and the contact pressure is sufficiently high so that the plug does not pop out in an uncontrolled manner. 【0037】 In preferred embodiments of the system, plug, and cannula, particularly for torsional connections, the sleeve is configured to be rotatably engaged with each other, particularly with male threads and the fastening members with female threads. In such embodiments, tensioning the cannula may be stepless, thus giving the user maximum control over the desired contour configuration of the cannula. In the particular case where the fastening member is female, the threads are positioned in a first area of ​​the plug so as to maintain a smooth surface inside the cannula to prevent contamination. 【0038】 In preferred embodiments of the system, plug, and cannula, particularly for torsional connection, the sleeve is provided with a projection and the fastening member is provided with grooves, the grooves configured to accommodate the projection. This embodiment relates to torsional connection, i.e., rotational coupling between the plug and the proximal cannula portion. Preferably, the fastening member has multiple grooves arranged such that a change of the projection from one groove position to a further groove position corresponds to an increase in cannula tension. Thus, the user gradually obtains control over the desired contour configuration. 【0039】 In particularly preferred embodiments of the system, plug, and cannula, the groove is "L-shaped" or "T-shaped" such that the projection is first inserted into the groove and then secured thereby by rotational movement. 【0040】 In a particularly preferred embodiment of the system, plug, and cannula, especially for clamp connection, the sleeve comprises at least one projection, and the plug device comprises at least one clamping member, the clamping member comprising a fastening member configured to engage with at least one projection of the sleeve or support sleeve. The fastening member is, for example, the projection. The connection is established when the fastening member engages with the projection. Thus, the fastening member and the projection may have complementary shapes, for example, to facilitate the connection of the two elements. To engage or disengage the connection, the fastening member is released from its connection with the projection by acting on the clamping member. This can be achieved, for example, by designing the clamping member to have a scissor shape where the fastening member is positioned at the tip of the scissor. The embodiment is advantageous in that there is no risk of the plug device accidentally releasing itself due to reduced frictional force, and the user is given good control over the desired contour configuration of the cannula. 【0041】 In a particularly preferred embodiment of the system and cannula, the sleeve has an inclined proximal portion. This creates a gap between the first and second sections when the second section is inserted into the sleeve, thus making it easier for the user to manually remove the plug from the sleeve. 【0042】 In a particularly preferred embodiment of the system and plug, the second area of ​​the plug device is at least partially tapered, and more particularly at least partially conical. The tapered or conical second area of ​​the plug device allows the contact pressure between the plug device and the sleeve to be preset. This means that, depending on the angle of inclination, a larger or smaller surface area of ​​the second area is pressed against the inner wall of the sleeve. Combined with, for example, a ring-shaped or annular projection, the contact pressure can be preset by the angle of inclination and the height of the projection positioned in the second area. 【0043】 In a particularly preferred embodiment of the system and plug, the first and second sections are formed in a cylindrical shape, with the second section having a smaller diameter than the first section. The different diameters simplify the user's manual removal of the plug from the sleeve. 【0044】 In a preferred embodiment of the support sleeve, the support sleeve is provided with an inclined proximal portion. This creates a gap between the first and second sections of the plug when the second section is inserted into the support sleeve, thus making it easier for the user to manually remove the plug from the sleeve. [Brief explanation of the drawing] 【0045】 [Figure 1] Figure 1 illustrates a cross-sectional view of a system according to one embodiment, comprising a cannula and a mandrel, wherein the cannula has a low profile configuration, and the plug is fully inserted into the lumen of the cannula and has four ring-shaped protrusions. [Figure 2] Figure 2 illustrates a cross-sectional view of a system according to one embodiment, which includes a cannula and a mandrel in a normal contour configuration, where the plug is partially conical and has three ring-shaped protrusions. [Figure 3] Figure 3 illustrates an enlarged view of the proximal end of a system according to one embodiment, where the plug is partially conical and has three ring-shaped protrusions. The sleeve has an inclined proximal portion that forms a gap. [Figure 4] Figure 4 illustrates three cross-sectional views of a system according to one embodiment, where the fastening member has a female thread and the sleeve has a male thread. [Figure 5] Figure 5 illustrates two cross-sectional views of a system according to one embodiment, where the fastening member has a female thread and the support sleeve has a male thread. [Figure 6] Figure 6 illustrates a cross-sectional view of a system according to one embodiment, in which the fastening member has three "L" shaped grooves and the sleeve has a protruding portion. [Figure 7] Figure 7 illustrates a cross-sectional view of a system according to one embodiment, in which the fastening member has three "L" shaped grooves and the support sleeve has a protrusion. [Figure 8] Figure 8 illustrates a cross-sectional view of a system according to one embodiment, which includes a clamp connection. The sleeve has several protrusions that engage with a fastening member positioned at the tip of a scissor-shaped clamp member. [Figure 9] Figure 9 illustrates a cross-sectional view of a system according to one embodiment, which includes a clamp connection. The support sleeve has several protrusions that engage with a fastening member positioned at the tip of a scissor-shaped clamp member. [Modes for carrying out the invention] 【0046】 Figure 1 shows a cross-sectional view of a system according to one embodiment, comprising a cannula 1 and a mandrel. The cannula 1 is in its normal configuration, and the mandrel is partially inserted into the lumen of the cannula body. The cannula body comprises a distal cannula portion 2 and a proximal cannula portion 3. The proximal cannula portion 3 includes a sleeve 3 to which a plurality of flexible filaments 4 forming the flexible body portion of the cannula 1 are attached. The mandrel comprises a plug 6 and an elongated member 10 having a distal end and a proximal end. The plug 6 is connected to the proximal end of the elongated member 10. The plug, in its second region 8, fits snugly into the sleeve 3 of the cannula 1 to form the proximal cannula portion 3, thereby sealing the inside of the proximal cannula portion 3 in a liquid-tight manner. The first region 7 of the plug remains outside the proximal cannula portion 3. The second region 8 is defined as part of the plug 6 and is inserted into the sleeve 5. The plug 6 has an opening 9 into which the proximal portion of the elongated member 10 is inserted and secured. The plug 6 has four ring-shaped protrusions 12 as fastening members 11 that function to increase the frictional force between the inner surface of the sleeve 5 and the outer surface of the second area 8 of the plug 6 in order to establish a press-fit connection between the sleeve 5 and the plug 6. Furthermore, the guide wire 18 is inserted into the plug 6 through the guide wire insertion opening 19 of the plug 6. 【0047】 Figure 2 illustrates a cross-sectional view of a system according to one embodiment, comprising a cannula 1 and a mandrel in a normal contour configuration, where the plug 6 is partially conical and includes three annular projections 12 as fastening members 11. The annular projections 12 are positioned on the tapered surface of the second section 8 of the plug 6. The taper angle, in combination with the dimensions of the annular projections 12, defines the contact pressure between the second section 8 of the plug and the sleeve 5. Because the annular projections 12 are arranged side by side, when the plug 6 is pulled back from the sleeve 5 and the cannula 1 is moved from a low-profile configuration to a normal-profile configuration, the connection pressure decreases gradually, and the plug 6 does not accidentally loosen completely. 【0048】 Figure 3 illustrates an enlarged view of the proximal end of a system according to one embodiment, where the plug 6 is partially conical and has three ring-shaped projections 12. The sleeve 5 has an inclined proximal portion that forms a gap 20 between the first section 7 and the second section 8 of the plug 6. Thus, when the second section 8 is inserted into the sleeve 5, it is easier for the user to manually remove the plug 6 from the sleeve 5. The gap depends on the inclination angle α, i.e., the inclination angle α defines the gap. In the embodiment shown in Figure 3, the second section 8 has three ring-shaped or annular projections 12 in the non-tapered region, while a further region of the second section 8 has a taper. The taper angle is defined by β and can be adjusted so that the connection pressure is a combination of press-fit through the ring-shaped or annular projections 12 and press-fit through the taper. Thus, when the plug 6 is removed from the sleeve 5, the press-fit through the taper produces a weaker connection pressure to prevent the plug 6 from immediately becoming completely loose. In addition, this facilitates the manipulation of the cannula in a controllable manner. The plug 6 further includes a slit 24 that penetrates the first and second sections 7 of the plug 6. The slit 24 functions to allow for compensation of fluid pressure between the inside and outside of the cannula 1. 【0049】 Figure 4 illustrates a cross-sectional view of a system according to one embodiment. The fastening member 11 has a female thread 14, and the sleeve 5 has a male thread 13. Thus, the plug 6 is U-shaped, while the second region 8 is symmetrically positioned like a pin in the center of the U-shaped plug 6. The sleeve 5's male thread 13 engages with the female thread 14 of the plug 6, thereby receiving the pin-shaped second region 8 in the center. The further the plug 6 is screwed into the sleeve 5, the greater the tension of the cannula 1. This allows for continuous adjustment of the tension of the cannula 1 according to the pitch of the threads 13 and 14. The second region further includes an opening 19 for inserting a guide wire 18. The second region 8 includes an elongated member 10. The entire embodiment is configured rotationally symmetrically. Alternatively, although not shown in Figure 4, the second region 8 may have a male thread 14 and the sleeve 5 may have a female thread 13. However, since sleeve 5 has a smooth inner surface that is easy to clean, the embodiment shown in Figure 4 advantageously reduces the risk of contamination. 【0050】 Figure 5 illustrates two cross-sectional views of a system according to one embodiment, where the fastening member 11 is equipped with a female screw 14 and the support sleeve 17 is equipped with a male screw 13. Essentially, the explanation shown in Figure 5 differs from the explanation shown in Figure 4 only in that the screw 13 is located in the support sleeve 17 and the support sleeve 17 is pressed into and fixed in the sleeve 5. Therefore, the support sleeve 17 has essentially the same effect as the sleeve 5 shown in Figure 4. 【0051】 Figure 6 illustrates a cross-sectional view of a system according to one embodiment, where the fastening member 11 has three L-shaped grooves 15, and the sleeve 5 has a projection 12. To establish a connection between the plug 6 and the sleeve 5, the sleeve 5 is inserted into the center of the plug 6, as indicated by the arrows in Figure 6. The projection 12 moves within a slit 24 provided for this purpose and derives from the "L-shaped" geometric shape of the three grooves 15, which are arranged, for example, along the central axis of symmetry in the embodiment. A rotation, indicated by another arrow in Figure 6, engages the projection 12 of the sleeve 5 with the plug 6, so that the tension of the cannula 1, which is strengthened by the insertion of the sleeve 5 into the plug 6, is maintained. The tension of the cannula 1 can be increased by further inserting the sleeve 5 into the next groove 15 of the plug 6. The level of tension of the cannula 1 can be changed in steps by the number of grooves 15. The distance between the grooves 15 thus determines the level of tension of the cannula 1. The grooves 15 shown in Figure 6 are "L-shaped". However, a "T" shaped groove 15 is also possible, as is any other shape configured to receive and hold the protrusion 12. 【0052】 Figure 7 illustrates a cross-sectional view of a system according to one embodiment, where the fastening member 11 is provided with three "L" shaped grooves 15, and the support sleeve 17 is provided with a protrusion 12. Thus, the embodiment shown in Figure 7 differs from the embodiment shown in Figure 6 in that the support sleeve 17 is pressed into the sleeve 5, and the support sleeve 17 has essentially the same effect as the sleeve 5 described above in Figure 6. 【0053】 Figure 8 illustrates a cross-sectional view of a system according to one embodiment, which includes a clamp connection. The sleeve 5 has several projections 12 that engage with a fastening member 11 positioned at the tip of a scissor-shaped clamp member 16. Thus, the fastening member 11 may have projections 12 that are particularly complementary in shape to the projections 12 positioned on the sleeve 5 in order to facilitate clamping between the sleeve 5 and the plug 6. To establish a connection between the plug 6 and the sleeve 5, the sleeve 5 is pushed into the second section 8 toward the proximal part of the plug 6 while the clamp member 16 is open. In Figure 8, the clamp member 16 is shown in the closed position. The open position is achieved, in particular by manually pressing the control surface 23, such that the clamp member 16 rotates away from the sleeve 5 around a pivot axis defined by the joint 21 for receiving the sleeve 5. If the control surface 23 is not actuated, the clamp member 16 automatically returns toward the sleeve 5 due to a spring element 22, and the connection is formed by the mutual engagement of the projections 12 of the sleeve 5 and the fastening member 11. Embodiments such as the one shown in Figure 8 have a rotationally symmetric structure. The distance between the projections 12 of the sleeve 5 defines various clamping positions between the plug 6 and the sleeve 5, corresponding to different levels of tension in the cannula 1. The tension level is progressively changed by the number of projections 12 arranged on the sleeve 5. The plug 6 further comprises an opening 9 configured to receive the proximal end of the elongated member 10. The spring element 22 may be, for example, a metal spring that deforms when actuated or some elastic material. The clamping element 16 may be metal or plastic and may be attached to the first section 7 or the second section 8 by a joint 21, for example, which may be a hinge, thereby forming a portion of the first section 7. The clamping member 16 is scissor-shaped, and the fastening member 11 is preferably located at the tip of the scissor. In the embodiment shown in Figure 8, the plug 6 is rotationally symmetric and has two opposing clamping members 16. Alternatively, fewer or more clamping members 16 may be arranged on the plug 6. The fastening members 11 of each clamp member 16 may have the same or different shapes.The fastening members 11 of each clamp member 16 are preferably fitted to their respective counterparts, namely the projections 12 located on the sleeve 5. For example, complementary shapes support the engagement between the fastening members 11 and the projections 12. 【0054】 Figure 9 illustrates a cross-sectional view of a system according to a further embodiment comprising a clamp connection. In the embodiment shown in Figure 9, a support sleeve 17 is also used and comprises several protrusions 12 that engage with fastening members 11 positioned at the ends of two scissor-shaped clamp members 16. The support sleeve 17 is pressed into the sleeve 5 and has essentially the same effect as the sleeve 5 shown in Figure 8. Thus, for the embodiment shown in Figure 9, the description given in Figure 8 can be essentially referenced. [Explanation of Symbols] 【0055】 1 Cannula 2. Distal cannula section 3. Proximal cannula 4 Flexible filaments 5 sleeves 6. Plugging device 7. First area of ​​the plug device 8. Second area of ​​the plug device 9. Opening of the plug device 10 Elongated member 11 Fastening members 12 Protrusion 13 Sleeve screws 14. Screws as fastening members 15 groove 16 Clamp member 17 Support sleeve 18 Guidewire 19 Guidewire insertion opening 20 gap 21 Joint 22 Spring elements 23 Control surface 24 slits

Claims

[Claim 1] A cannula (1) having a distal cannula portion (2) and a proximal cannula portion (3), particularly for use in medical applications, wherein the cannula (1) is equipped with a plurality of flexible filaments (4) so ​​that it can change between a normal contour configuration and a low contour configuration, and the proximal cannula portion (3) is formed by a sleeve (5), and the cannula (1) is equipped with a plurality of flexible filaments (4), and the proximal cannula portion (3) is formed by a sleeve (5), A plug device (6) comprising a first area (7) and a second area (8), wherein the second area (8) is configured to be releasably positioned within the sleeve (5), and the second area comprises an opening (9) for receiving the proximal portion of an elongated member (10), The plug device (6) includes at least one fastening member (11) configured to establish a press-fit connection and / or torsion connection and / or clamp connection between the sleeve (5) and the plug device (6), such that the cannula (1) transitions from the normal contour configuration to the low-profile configuration when the plug device (6) engages with the sleeve (5). A system for venous drainage. [Claim 2] The system according to claim 1, wherein the proximal cannula portion (3) is formed by a support sleeve (17). [Claim 3] The system according to claim 1 or 2, wherein the fastening member (11) is provided with a ring-shaped projection (12) in particular for press-fit connection. [Claim 4] The system according to any one of claims 1 to 3, wherein, in particular for the torsional connection, the sleeve (5) is configured to be particularly equipped with a male thread (13), and the fastening member (11) is configured to be particularly equipped with a female thread (14), and to be configured to be rotatably engaged with each other. [Claim 5] The system according to any one of claims 1 to 4, in particular for the torsional connection, wherein the sleeve (5) is provided with a projection (12), the fastening member (11) is provided with a groove (15), and the groove (15) is configured to accommodate the projection (12). [Claim 6] The system according to claim 5, wherein the groove is "L-shaped" or "T-shaped". [Claim 7] The system according to any one of claims 1 to 6, in particular for the clamp connection, wherein the sleeve (5) is provided with a projection (12), the plug device (6) is provided with a clamp member (16), and the clamp member (16) is provided with a fastening member (11) configured to engage with the projection (12) of the sleeve. [Claim 8] The system according to any one of claims 1 to 7, wherein the sleeve (5) has an inclined proximal portion. [Claim 9] The system according to any one of claims 1 to 8, wherein the second region (8) is at least partially tapered, and in particular at least partially conical in shape. [Claim 10] The system according to any one of claims 1 to 9, wherein the first region (7) and the second region (8) are formed in a cylindrical shape, and the second region (8) has a smaller diameter than the first region (7). [Claim 11] A plug device for use in medical cannulas, wherein the cannula (1) can change between a normal contour configuration and a low contour configuration, and the cannula (1) comprises a proximal cannula portion (3) formed by a sleeve (5), particularly by a support sleeve (17), and a plurality of flexible filaments (4), The plug device (6) comprises a first area (7) and a second area (8), the second area (8) being configured to be releasably positioned within the sleeve (5), particularly within the support sleeve (17), and having an opening (9) for receiving the proximal portion of an elongated member (10), and the plug device (6) comprising at least one fastening member (11) configured to establish a press-fit connection and / or torsion connection and / or clamp connection between the sleeve (5), particularly the support sleeve (17) and the plug device (6), such that when the plug device (6) engages with the sleeve (5), particularly the support sleeve (17), the cannula (1) transitions from the normal contour configuration to the low contour configuration. [Claim 12] A support sleeve for forming a proximal cannula portion (3) for use in a cannula (1) particularly for medical applications, wherein the cannula (1) comprises a plurality of flexible filaments (4) so ​​that the cannula (1) can change between a normal contour configuration and a low contour configuration, and the support sleeve (17) comprises a male thread (13) and / or projection (12) and / or groove (15) configured to establish a press-fit connection and / or torsion connection and / or clamp connection between the cannula (1) and a plug device (6). [Claim 13] The support sleeve according to claim 12, comprising an inclined proximal portion. [Claim 14] A cannula having a distal cannula portion (2) and a proximal cannula portion (3), particularly for use in medical applications, wherein the cannula (1) comprises a plurality of flexible filaments (4) so ​​that the cannula (1) can change between a normal contour configuration and a low contour configuration, and the proximal cannula portion (3) is formed by a sleeve (5), particularly by a support sleeve (17), and the sleeve (5), particularly the support sleeve (17), comprises particularly male threads (13) and / or protrusions (12) and / or grooves (15) configured to establish press-fit connections and / or torsion connections and / or clamp connections between the sleeve (5), particularly the support sleeve (17) and a plug device (6). [Claim 15] A cannula (1) having a distal cannula portion (2) and a proximal cannula portion (3), particularly for use in medical applications, wherein the cannula (1) is equipped with a plurality of flexible filaments (4) so ​​that it can change between a normal contour configuration and a low contour configuration, and the proximal cannula portion (3) is formed by a sleeve (5), particularly by a support sleeve (17), and A plug device (6) comprising a first area (7) and a second area (8), wherein the second area (8) is configured to be releasably positioned within the sleeve (5), particularly within the support sleeve (17), and the second area comprises an opening (9) for receiving the proximal portion of an elongated member (10), The plug device (6) includes at least one fastening member (11) configured to establish a press-fit connection and / or torsion connection and / or clamp connection between the sleeve (5), particularly the support sleeve (17), and the plug device (6), such that the cannula (1) transitions from the normal contour configuration to the low contour configuration when the plug device (6) engages with the sleeve (5), particularly the support sleeve (17). A kit of parts.

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