EP4262591A1

EP4262591A1 - Suprapubic cannula

Info

Publication number: EP4262591A1
Application number: EP21840835.9A
Authority: EP
Inventors: Hans Haindl
Original assignee: Uromed Kurt Drews GmbH
Current assignee: Uromed Kurt Drews GmbH
Priority date: 2020-12-18
Filing date: 2021-12-16
Publication date: 2023-10-25
Also published as: WO2022129399A1; DE102020216328A1

Abstract

The invention relates to a suprapubic cannula (10) for puncturing body cavities, having an outer, longitudinally cut sleeve (12) with proximal and distal ends (14, 16) and an inner, longitudinally cut sleeve (18) with proximal and distal ends (20, 22). The inner sleeve (18) is blunt at its distal end (22), and the outer sleeve (12) has a puncturing point (24) at its distal end (16). The proximal end (14) of the outer sleeve (12) is connected to a first grip section (26), and the proximal end (20) of the inner sleeve (18) is connected to a second grip section (28). The first and second grip sections (26, 28) are in engagement with each other via a thread (30) such that rotation of the two grip sections (26, 28) relative to each other transfers the cannula (10) from a first state to a second state. In the first state of the cannula (10), the longitudinal cut (34) in the inner sleeve (18) is covered by the outer sleeve (12), and the puncturing point (24) of the outer sleeve (12) is exposed for puncturing. In the second state of the cannula (10), the longitudinal cuts (32, 34) of the inner and outer sleeves (12, 18) come to lie one above the other, and the puncturing point (24) of the outer sleeve (12) is overlapped, preferably completely, by the distal end (22) of the inner sleeve (18).

Description

suprapubic cannula

The present invention relates to a suprapubic cannula for puncturing body cavities.

In various areas of medicine, there is the problem that a catheter is inserted into a body cavity through a cannula and that the cannula can then no longer be removed over the firmly connected attachment of the catheter. Various solutions are known in the prior art for dealing with this problem. For example, in the case of central venous catheters, protective plastic bags were attached over the cannula to prevent damage to the catheter or injury to the patient or user. The problem mentioned above is also known from the field of urology. The suprapubic puncture of the bladder (ie through the abdominal wall) has become established to enable long-term artificial urinary diversion. So-called suprapubic catheters are used for this purpose, the infection rate of which is lower than that of catheters that are inserted through the urethra. The problem also arises with these suprapubic catheters that the cannula cannot be removed via the attachment of the catheter once the catheter has been inserted and the cannula has been pulled out of the body again. However, the cannula cannot be left on the catheter as it would easily damage the catheter and/or injure the patient. In order to allow the cannula to be removed from the catheter, it is known to split the cannula after use. For example, the user pulls two handles in opposite directions and thus splits the cannula in its longitudinal direction. The two cannula halves can then be easily removed from the catheter. Such cannulas are known, for example, from DE 43 16 793 C1, DE 2 104 211 01, DE 698 37 667 T2 and DE 10 2005 015 556 A1. Examples of splittable cannulas are rolled cannulas, which have an open slit on one side and are pre-weakened on the other side, or cannulas closed all round but mechanically pre-weakened on two sides, and laser-perforated cannulas.

However, the splitting process requires considerable force and involves a high risk of injury for the user. The split edges of the cannulas are often covered with sharp burrs that can cause cuts if touched.

An alternative known from the prior art, in which the cannula does not have to be split, is the so-called channel cannula, from which the catheter can be removed laterally. Examples of such channel cannulas are described in EP 0 499 147 B1 and DE 41 03 977 A1. US Pat. No. 3,545,443 and DE 33 47 150 A1 describe cannulas which consist of two longitudinally cut sleeves which overlap one another.

The techniques described above for detaching the cannula from the catheter, in particular through slits, have been widely introduced in Germany and other European countries in inpatient settings. However, it has been shown that there are reservations about this technique in the outpatient sector, since urologists, for example, who do not constantly perform the suprapubic puncture, are afraid of potential complications. This includes in particular secondary bleeding, the frequency of which is described in the literature as 8.5 to 18.2%. From this secondary bleeding, 0.01 to 4.3% require treatment, which in extreme cases can lead to surgical interventions and/or blood transfusions. In rare cases, injuries to abdominal organs, such as the intestines or large vessels, have also been reported.

So far, all of this has prevented the use of suprapubic bladder drainage in outpatient settings, although guideline AWMF 029-007 S1 on urinary drainage expressly requires it for catheterizations longer than five days. In the USA, too, suprapubic drainage is only used hesitantly because claims for damages are feared if complications arise. In addition, the techniques described for detaching the cannula from the catheter, for example by means of a split cannula, are susceptible to damage to the catheter, which can occur in particular when the catheter is detached from or from the cannula. Such damage can impair the functionality of the catheter.

Even if the documents last mentioned reduce the risk of injury in that there are no split edges with sharp burrs, the proposed solutions do not eliminate the risk of injuring yourself on the extremely sharp puncture tip of the cannula and possibly becoming infected. According to the applicable accident prevention regulation TRBA 250, hospital operators are required to provide their employees with injury-proof cannula systems. For example, in the field of urology for the suprapubic bladder function, there is not yet a completely injury-proof system available.

With regard to the risk of injury for the user, some solutions are now known. For example, US Pat. No. 7,708,721 B2 describes a cannula with inner and outer sleeves that can be displaced relative to one another. However, the needle tip of the inner sleeve cannot be fixed in the retracted safety position, so it cannot be prevented that the needle tip comes out again and causes injuries. Furthermore, the thread guide described in US Pat. No. 7,708,721 B2 cannot be technically implemented, or only with unreasonable effort.

The constructive solution described in EP 2667 804 B1 offers a higher level of security with two inner and outer sleeves that can be rotated in opposite directions via a thread, which lead to reliable protection of the cannula tip, since the inner sleeve can be secured in the outer sleeve in the retracted state.

However, this design also only solves the user's injury problem; it does not reduce the risk of injury to the patient.

Furthermore, DE 10 2018 005 848 A1 discloses a cannula with an inner and an outer sleeve. The inner sleeve is rotatably disposed within the outer sleeve between a first rotational position and a second rotational position. In the first rotational position, the inner sleeve can be displaced within the outer sleeve between a first sliding position and a second sliding position in order to expose or secure a ground puncture tip. However, there is also an increased risk of injury to the patient and/or the user with this construction. In addition, the construction of this cannula requires increased operating effort and offers poor ergonomics for the user of the cannula.

It is therefore an object of the present invention to provide a cannula for puncturing body cavities that reduces both the risk of injury and thus infection for the user and the risk of injury or complications for the patient and/or offers increased ergonomics and ease of use for the user .

This object is achieved with a cannula according to claim 1. Preferred embodiments are described in the dependent claims and the following description.

The present invention relates to a suprapubic cannula for puncturing body cavities. The suprapubic cannula has an outer elongate sleeve or trough cannula with proximal and distal ends and an inner elongate sleeve or trough cannula also with proximal and distal ends.

Within the meaning of the present invention, proximal is to be understood as meaning an arrangement directed towards the user of the cannula. Distal, on the other hand, means an arrangement directed away from the user of the cannula. Accordingly, for example, a proximal end of a component is arranged closer to the user of the cannula than the corresponding distal end of the same component.

The inner sleeve or channel cannula is blunt at its distal end so that it essentially cannot cut any tissue. The outer sleeve or channel cannula has a puncture point at its distal end, with which human and/or animal tissue can be incised.

The proximal end of the outer sleeve is connected to a first handle portion and the proximal end of the inner sleeve is connected to a second handle portion. The first and second handle portions are threadably engaged with one another such that twisting the two handle portions relative to one another converts the cannula from a first condition to a second condition. In the first state of the cannula, the longitudinal section of the inner sleeve is covered by the outer sleeve and the puncture tip of the outer sleeve is exposed for puncture.

In the second state of the cannula, the longitudinal sections of the inner and outer sleeve come to lie one above the other. Also, in the second condition of the cannula, the puncture tip of the outer sheath is overlapped by the distal end of the inner sheath. Preferably, in the second condition of the cannula, the puncture tip of the outer sleeve is completely overlapped by the distal end of the inner sleeve.

Since the inner sleeve is at least partially arranged inside the outer sleeve at least in the second state, the puncture tip of the outer sleeve is covered or preferably completely covered by the distal end of the inner sleeve, viewed from inside the inner sleeve.

The suprapubic cannula according to the invention minimizes both the risk of injury to the user and the risk of injury to the patient. The risk of injury for the patient, in particular the risk of secondary bleeding, is essentially due to the fact that a large-bore, sharply ground cannula is used, which, in addition to its sharp tip, also has sharp ground flanks and a sharp rear ground eye, which can result in punching out in the tissue can lead.

In addition, the risk of damage to the catheter can be at least reduced by the suprapubic cannula according to the invention compared to the techniques described above.

When using a channel cannula, as is also described in EP 2 667 804 B1, there is no such rear ground eye (since this is where the longitudinal section of the sleeve is located), but the sharp proximal ground parts or the lateral sharp ground flanks of the cannula can also lead to cutouts. This injury mechanism is greatly reduced within the scope of the present invention in that the inner sleeve is blunt at its distal end and the outer sleeve has a ground puncture tip only at its distal end (in contrast to EP 2 667 804 B1, according to which the inner sleeve has the puncture tip). This makes it possible to fill the cavity of the sharply ground outer sleeve with the blunt, distal end of the inner sleeve in such a way that only the ground puncture tip can cut and the rest of the cannula tip merely stretches the tissue. In addition, according to the invention, the connection of the first and second handle sections via the thread means that the two handle sections can rotate relative to one another from the first state, in which the puncture tip of the outer sleeve is exposed for puncture, to the second state, in which the puncture tip of the outer sleeve is overlapped or covered by the distal end of the inner sleeve. Thus, the user can expose and/or cover or secure the puncture tip, if necessary, simply by rotating the two grip sections relative to one another.

This enables greater ergonomics and improved usability of the cannula.

The outer and inner longitudinally cut sleeves or channel cannulas can be conventional channel cannulas. For example, two overlapping two-thirds shells can be provided as inner and outer sleeves. The proportion of the longitudinal section in the total circumference of the sleeve (in cross section) is preferably between 25 and 45%, more preferably between 30 and 40%. In the first turning position, the longitudinal sections of the inner and outer sleeve overlap only minimally on one side and by 100° - 150° on the other side. In the second rotational position, the longitudinal cuts preferably essentially completely overlap. Preferably, the inner sleeve must be rotated between the first and second rotational position by an angle of between 90° and 170°, preferably between 100° and 150° (in contrast to EP 2 667 804 B1, in which a rotation of 180° is required).

The two handle sections can preferably be latched together in the first state and/or in the second state. The two handle sections can preferably be releasably locked together in the first state and non-releasably locked together in the second state.

A latching of the two handle sections in the first state, in which the puncture tip of the outer sleeve is exposed for the puncture, can ensure that the puncture tip is fixed relative to the inner sleeve during the puncture process. This allows a safe and effective puncture procedure to be made possible.

Locking the two handle sections in the second state, in which the puncture tip of the outer sleeve is overlapped or covered by the distal end of the inner sleeve, can prevent or at least prevent the puncture tip from being unintentionally exposed, for example after the cannula has been removed again after the puncture procedure reduce the risk of exposing the puncture tip. The latchability of the two handle sections can be implemented, for example, by a latching or locking element that is provided on one of the two handle sections and that engages in a counter-element that can be provided on the other of the two handle sections, and thus the two handle sections relative to one another can lock.

The latching or locking element can be, for example, a lug or a projection which can interact with a counter-element in order to be able to cause the two handle sections to latch. For example, the lug or projection can engage in a recess or opening provided on the other handle section. Alternatively, the counter-element can also be a nose or a projection which is provided on the other handle section.

However, it is also conceivable to design the latching or locking element as a deflectable element. For example, the latching or locking element can be designed as a flexible element which can be moved and/or deformed to engage or disengage. However, it is also conceivable to provide the latching or locking element with a spring. In this case, the spring can be compressed or stretched when the latching or locking element engages and/or disengages in order to deflect the latching or locking element and to facilitate the locking of the two handle sections.

Preferably, the two handle sections can each have a longitudinal section which each form a continuation of the longitudinal section of the sleeve connected to the respective handle section. In the second state of the cannula, the longitudinal cuts of the two grip sections can preferably come to lie on top of one another.

Thus, in the second state, a continuous gap can be formed in the cannula along the cannula, from which a catheter or similar medical instrument arranged in the inner sleeve of the cannula can be removed.

Since this continuous gap only exists in the second state, in which the puncture tip of the outer sleeve is overlapped or covered by the distal end of the inner sleeve, the cannula can only be removed from the catheter or a similar medical instrument when the puncture tip of the outer sleeve is overlapped or covered in the second state by the distal end of the inner sleeve. As a result, the risk of injury to the patient and/or the user can be reduced, as a result of which the safety and user-friendliness of the cannula can be additionally increased.

The first handle section preferably has a proximal end and a distal end. Furthermore, the thread can preferably be defined by the shape of the proximal end of the first handle portion.

For example, the first handle section can have a wall, preferably a peripheral wall, whose end face arranged at the proximal end of the first handle section has at least one, preferably continuous, course that defines the thread. The first handle section can also have a plurality of such course sections, which each and/or independently of one another define a thread with a thread pitch.

Thus, the thread can be easily and efficiently integrated into the first handle portion. As a result, the manufacturing costs and the complexity of the cannula can be reduced. Furthermore, the structure and/or the operation of the cannula can be simplified as a result.

Preferably, the proximal end of the first handle section can form two helical sections.

The helical sections can preferably be arranged diametrically opposite one another. In addition, the helical sections can preferably be formed at one end, preferably the proximal end, of a wall, preferably a peripheral wall, of the first handle section.

The helical sections can preferably each be defined by a profile of an end face of a wall, preferably a peripheral wall, of the first handle section.

Preferably, the second handle portion can have two bearing surfaces that can slide respectively on the two helical portions.

The two helical sections thus provide guide surfaces on which the bearing surfaces of the second handle section can slide from the first state into the second state when the two handle sections are rotated relative to one another. The guide surfaces and/or the helical sections can have a surface treatment, for example a coating, which can make it easier for the guide surfaces to slide off the helical sections.

Alternatively or additionally, the second handle section can have rollers that can roll along the respective helical section.

Preferably, the two helical sections each have at least one locking lug. The respective latching lug can be set up to latch into a counter-element, which can preferably be provided on the second handle section. As a result, the two handle sections can be latched to one another and locked relative to one another in the first state and/or in the second state.

Preferably, the two helical sections each have a collar that extends at least partially along the respective helical section. The collar may preferably be configured to at least partially engage a portion of the second handle portion.

The collar can preferably be formed on a, preferably circumferential, wall of the first handle section. The flange can preferably protrude essentially perpendicularly to the wall. Also preferably, the collar may extend in a direction away from an interior space defined by the wall of the first handle portion.

The collar can provide a stop for the second grip section, at least in a rotational angle range of the first or second grip section, through the interaction with a region of the second grip section, in particular through an engagement of the second grip section with the first grip section by means of the collar. This can at least reduce the risk of the first handle section and/or the second handle section detaching from the cannula and getting lost.

In addition, the collar can provide a guide surface on which at least a region of the second handle section can slide and/or roll.

The first handle section can preferably at least partially enclose the second handle section in the first state and/or in the second state. This allows the cannula to be constructed in a compact and space-saving manner. The second handle section can preferably have at least one tab, preferably two tabs arranged diametrically opposite one another. The tab can run at least in regions along an outer surface of the first grip section, preferably essentially parallel to the longitudinal axis of the outer sleeve and/or the inner sleeve.

The outer surface of the first handle section can preferably be formed by a wall, preferably a peripheral wall, of the first handle section. The tab may provide a gripping facility for the user to manually grasp the second handle portion and rotate relative to the first handle portion, for example from the first condition to the second condition or vice versa. To this end, the tab may include features that may facilitate gripping by the user and/or at least reduce slippage in the user's hand. For example, the outwardly and user-accessible surface of the tab may be rough, preferably rougher than the remainder of the second handle portion, and/or may include ribs that may enhance adhesion between the user's hand and the tab.

Alternatively or additionally, the first grip section can be rough in some areas and/or have gripping ribs to improve adhesion between the user's hand and the first grip section and thus prevent or at least reduce slipping of the first grip section in the user's hand.

As a result, the ergonomics and the ease of use of the cannula can be increased. At the same time, the provision of a compact and, in relation to the total area of the first and/or the second handle section, a relatively small-area tab provides a space-saving gripping option.

Preferably, the tab may include at least one protrusion adapted to engage the collar of the first handle portion. Through the interaction of the projection formed on the tab with the collar, the collar can provide a stop surface for the projection, at least in a rotational angle range of the first or second handle section. This can at least reduce the risk of the first handle section and/or the second handle section detaching from the cannula and getting lost. In addition, the projection on the collar can be guided when the handle portions are rotated between the first and second states. Preferably, the distal end of the inner sleeve has an inturned tongue. The inner sleeve can at least partially form a lumen. The tongue may be curved in a direction directed towards the lumen, which may be understood by the term "inward".

On the one hand, the inwardly bent tongue can prevent tissue from being punched out during the puncture process, in that the tongue provides an inclined surface over which the tissue can push away and slide off during the puncture process.

On the other hand, because the inturned tongue can be bent in a direction directed toward the lumen formed by the inner sleeve, the tongue can provide a stop for a catheter inserted prior to the puncture procedure. As a result, the insertion depth of the catheter into the inner sleeve can be limited or at least defined by the tongue. Thus, the user can dispense with references with regard to the insertion depth of the catheter into the inner sleeve, for example in the form of length markings provided on the catheter. This can increase ease of use and safety of the cannula.

The first handle section can preferably have a threading aid for a catheter. Before the puncture process, a catheter or a similar medical instrument is usually threaded into the inner sleeve or the outer sleeve and then guided through the inner and outer sleeve. Preferably, either the inner or outer sleeve projects further proximally than the other of the inner or outer sleeve. Particularly preferably, the inner sleeve protrudes further in the proximal direction than the outer sleeve.

Thus, the catheter is preferably threaded into only one of the inner and outer sheaths, rather than being threaded into both the inner and outer sheaths simultaneously. Due to the longitudinal section of the inner and outer sleeve, there is no closed lumen at the threading point of the catheter into the inner or outer sleeve, which is completely delimited over the circumference by a wall of the inner or outer sleeve.

When threading the catheter in, it can therefore happen that the catheter can emerge from the longitudinal section of the inner or outer sleeve and thus cannot be guided through the inner and outer sleeve. Leaking of the catheter from the longitudinal section of the inner or outer sleeve is also encouraged by the fact that Catheters are often bent or flexible. This can also make it difficult to thread the catheter in a straight line.

The threading aid provided can make it easier to thread the catheter into the inner or outer sleeve in order to avoid the situation described above.

The threading aid can preferably be positioned in the first grip section in such a way that it is arranged on the side of the longitudinal section of the inner sleeve when the cannula is in the first state. As a result, the catheter can be prevented from escaping from the longitudinal section of the inner sleeve when the catheter is being threaded in, or at least the risk of the catheter escaping from the longitudinal section of the inner sleeve can be reduced.

The threading aid can preferably be designed as a web that protrudes from a surface of the first handle section. The web can preferably extend in a direction which runs essentially parallel to the longitudinal axis of the inner sleeve and/or the outer sleeve.

The threading aid or the web can have a proximal end and a distal end. The threading aid or the web preferably has a beveled surface at the proximal end in order to further facilitate threading. In this way, the catheter can slide off along the beveled surface when being threaded in and thereby be pushed into the inner sleeve.

The threading aid can preferably be at least partially deflectable and/or deformable, so that the second grip section can at least partially deflect and/or bend the threading aid from the inner sleeve, preferably outwards, during the transition from the first state to the second state.

For example, the threading aid, which can be designed as a web, for example, can be flexible, so that the second grip section can displace at least one area of the threading aid during the transition from the first state to the second state. The threading aid can be deformed in the process, so that the shape of the threading aid is thereby changed, at least temporarily.

Alternatively or additionally, the threading aid can essentially retain its shape during the transition from the first state to the second state. Instead, the threading aid can be used as a whole by the second handle section during the transition from the first state to the second state are deflected rotationally and / or translationally. For example, the threading aid can have a spring for this purpose, which can be compressed or stretched to deflect the threading aid.

A combination of a deformation and a deflection of the threading aid is also conceivable.

In the second state of the cannula, the threading aid can preferably latch with the second grip section, preferably in a non-detachable manner. In the second state of the cannula, the threading aid can preferably snap into place with the second grip section by springing back, preferably in a non-detachable manner.

By locking the two grip sections by means of the threading aid in the second state, in which the puncture tip of the outer sleeve is overlapped or covered by the distal end of the inner sleeve, the puncture tip can be unintentionally exposed, for example after the cannula has been removed again after the puncture procedure. prevent or at least reduce the risk of exposure of the puncture tip.

This can reduce the risk of injury from the cannula. The safety and user-friendliness of the cannula can thus be increased.

The cannula can preferably be designed in such a way that a complete turning back from the second state into the first state is prevented. Preferably, the inner sleeve expands in the second state, making it impossible to rotate back to the first state.

Such a locking of the cannula in the second state, in which the puncture tip of the outer sleeve is overlapped or covered by the distal end of the inner sleeve, can prevent or prevent an unintentional exposure of the puncture tip, for example after the cannula has been removed again after the puncture procedure. reduce the risk of exposing the puncture tip.

Preferably, the transfer of the cannula from the first state to the second state can require a relative rotation of the grip sections to one another of 90°-170°, preferably of 100°-150°. The thread can preferably have a thread pitch which is smaller in the area of the first state than in the rest of the thread. The thread can preferably be flat in the area of the first state or have an opposite inclination. As a result, the risk of an unintentional twisting of the first handle section relative to the second handle section from the first state to the second state can be reduced.

The invention also relates to a kit with a cannula which is designed in one of the ways according to the invention or preferred above. The kit also has a catheter which can be accommodated in the inner sleeve of the cannula. In the second state of the cannula, the catheter can be removed from the cannula through the longitudinal cuts in the sleeves lying one above the other.

The features and advantages described herein for the cannula also apply to the kit accordingly.

Preferred embodiments of the present invention are described below with reference to the figures. Show it:

1 shows a side view of an embodiment of a cannula according to the invention, the cannula being in the first state;

FIG. 2 shows a bottom view of the cannula according to the embodiment from FIG. 1;

FIG. 3 shows a plan view of the cannula according to the embodiment from FIG. 1;

FIG. 4 shows an exploded view of the cannula according to the embodiment from FIG. 1 ;

Fig. 5 shows a cross section of the cannula according to the embodiment of FIG

line 5-5 with the cannula in the first state;

FIG. 6 is a cross-sectional view of the cannula of the embodiment of FIG. 1 taken along line 5-5 with the cannula in the second condition;

FIG. 7 perspective detailed views of the first and the second grip section of the cannula according to the embodiment from FIG. 1 ; FIG. 8 shows a perspective view of the cannula according to the embodiment from FIG. 1 , with the cannula being in the first state; FIG.

FIG. 9 shows a perspective view of the cannula according to the embodiment from FIG. 1 , with the cannula being in the second state.

1 shows a suprapubic cannula 10 having an outer longitudinally cut sleeve 12 having a proximal end 14 and a distal end 16 and an inner longitudinally cut sleeve 18 also having a proximal end 20 and a distal end 22 . The inner sleeve 18 is blunt at its distal end 22 . In contrast to this, the outer sleeve 12 has a puncture tip 24 at its distal end 16 in order to be able to cut tissue.

In addition, the cannula 10 has two grip sections 26 , 28 . The first handle portion 26 is connected to the proximal end 14 of the outer sleeve 12 and the second handle portion 28 is connected to the proximal end 20 of the inner sleeve 18 . Further, the first handle portion 26 partially envelops the second handle portion 28, i.e., the second handle portion 28 is partially disposed within the first handle portion 26.

The first and second handle sections 26, 28 are engaged with one another via a thread 30 in such a way that twisting the two handle sections 26, 28 relative to one another converts the cannula 10 from a first state into a second state.

The first handle portion 26 has a proximal end 35 and a distal end 37 . The thread 30 includes two helical sections 31 , 33 formed on the proximal end 35 of the first handle section 26 . The thread 30 or the two helical sections 31 , 33 are defined by the shape of the end face of the first grip section 26 arranged at the proximal end 35 . More precisely, the two helical sections 31 , 33 which define the thread 30 are defined by the course of the proximal end face of the first handle section 26 . The first handle section can also have a number of courses which each and/or independently of one another define a thread 30 with a specific thread pitch.

The outer and inner slit sleeves 12, 18 each have a slit 32, 34 best seen in FIG. FIG. 2 shows a view of the cannula 10 according to the embodiment from FIG. 1 from below, ie from the left as viewed in FIG. 1 . FIG. 3, on the other hand, shows a view of the cannula 10 according to the embodiment from FIG. 1 from above, ie from the right as viewed in FIG

In the first state of the cannula 10, the longitudinal section 34 of the inner sleeve 18 is covered by the outer sleeve 12 and the puncture tip 24 of the outer sleeve 12 is exposed for puncture. In contrast to this, in the second state of the cannula 10, the longitudinal cuts 32, 34 of the inner and outer sleeves 12, 18 come to lie one above the other. The puncture tip 24 of the outer sleeve 12 is overlapped or covered by the distal end 22 of the inner sleeve 18 .

Second handle portion 28 further includes two diametrically opposed tabs 38 that run along an outer surface of first handle portion 26 substantially parallel to the longitudinal axis of outer sleeve 12 and inner sleeve 18 .

Furthermore, the outer and inner handle sections 26, 28 each have a longitudinal section 40, 42. The longitudinal cuts 40, 42 each form a continuation of the longitudinal cut 32, 34 of the sleeve 12, 18 connected to the respective grip section 26, 28. In the second state of the cannula 10, the longitudinal cuts 40, 42 of the two grip sections 26, 28 come to lie one above the other. As a result, the longitudinal cuts 32, 34 of the outer and inner sleeves 12, 18 together with the longitudinal cuts 40, 42 of the two handle sections 26, 28 in the second state can form a continuous gap around a catheter which has been inserted into the inner sleeve 18 , to be removed from the cannula 10 after the puncture procedure. Such a condition is shown in Figs.

In FIGS. 1, 2, 3, 5 and 8 the cannula 10 is in the first state. In this first state, the longitudinal cuts 40, 42 of the two handle sections 26, 28 are not superimposed. Likewise, in the first state, the longitudinal section 34 of the inner sleeve 18 is also not exposed, since it is covered by the outer sleeve 12 . In the first state, therefore, no gap is formed through which a catheter can be removed from the cannula 10.

In FIGS. 6 and 9, the cannula 10 is in the second state. In this second state, the longitudinal cuts 40, 42 are superimposed. In addition, the longitudinal cuts 32, 24 are one above the other. Both the first handle portion 26 and the tabs 38 have gripping ribs 44 to facilitate gripping by the user and to at least reduce slippage of the first handle portion 26 and the tabs 38 in the user's hand.

Further, the distal end 22 of the inner sleeve 18 has a tongue 46 bent inward. On the one hand, the inwardly bent tongue 46 can prevent tissue from being punched out during the puncturing process, in that the tongue 46 provides an inwardly inclined surface over which the tissue can push away and slide off during the puncturing process.

In addition, the second handle section 28 has markings 48 which indicate the direction of rotation in order to bring the cannula 10 from the first state to the second state.

In addition, the cannula 10 has a threading aid 49 (see FIGS. 5 to 7) for a catheter in order to facilitate threading a catheter into the inner sleeve 18 . The threading aid 49 is positioned in the first grip section 26 in such a way that it is arranged on the side of the longitudinal cut 34 of the inner sleeve 18 in the first state of the cannula 10 . According to the embodiment shown in the figures, the threading aid 49 is designed as a web which protrudes from an inner surface of the first handle section 26 .

The threading aid 48 has a proximal end 50 and a distal end 52 . The threading aid 49 has a beveled surface 54 at the proximal end 50 in order to further facilitate the threading of a catheter into the inner sleeve 18 . This allows the catheter to slide along the beveled surface 54 during threading and thereby be forced into the inner sleeve 18 .

The threading aid 49 can be deflected or deformed. As a result, the threading aid 49 of the inner sleeve 18 can be deflected or bent outwards by the second grip section 28 during the transition from the first state to the second state. This state is shown in FIG. 6, for example.

The cannula 10 also has three latching lugs 56, 58, 60, which are each formed on the helical sections 31, 33. These detents 56, 58, 60 are best visible in FIGS. The latching lugs 56, 58 are arranged in a region of the helical sections 31, 33 which can be assigned to the first state of the cannula 10. Consequently the latching lugs 56, 58 can be used in the first state to interact with corresponding counter-elements provided on the second handle section 28 in order to latch the two handle sections 26, 28 to one another in the first state. The corresponding counter-elements provided on the second handle section 28 are not visible in the figures.

The detent 60 is arranged in an area of the helical section 31 which can be assigned to the second state of the cannula 10 . Thus, the detent 60 can serve to interact in the second state with at least one corresponding counter-element provided on the second handle section 28 in order to latch the two handle sections 26, 28 to one another in the second state. The corresponding counter-element provided on the second handle section 28 is also not visible in the figures.

The second handle section 28 has two bearing surfaces 61 (not visible in the figures), which can each slide on the two helical sections 31, 33 when the second handle section 28 is rotated relative to the first handle section 26 between the first and the second state.

In addition, the two helical sections 31 , 33 each have a collar 62 which extends along the respective helical section 31 , 33 . The tabs 38 each have a corresponding projection 64 (see Figs. 2, 4 and 7) which is engageable with the underside, i.e. at the distal end, of the respective collar 62 to permit detachment of the second handle portion 28 from the first Handle portion 26 to prevent. In addition, the underside of the respective collar 62 can serve as a sliding surface for the projections 64, for example when the cannula 10 is to be rotated from the second state back to the first state.

The first handle section 26 also has a stop 66 (see FIGS. 4 and 7) which can serve to limit the angle of rotation of the second handle section 28 relative to the first handle section 26 by a region of the second handle section 28 in the region of the first and second state to the stop 66 comes to rest.

In order to transfer the cannula 10 from the first state to the second state, for example after the end of a puncture procedure, the user can grip the second handle section 28, for example on the tabs 38. The user can then initiate a rotational movement on the second handle section 28. The second grip section 28 can first be released from its latching on the latching lugs 56 , 58 with the first grip section 26 . The cannula 10 is then brought into the second state in that the second handle section 28 is rotated relative to the first handle section 26 until it latches with the locking lug 60 . The second handle section 28 slides along the helical sections 31 , 33 of the thread 30 .

When rotating the second handle section 28, the second handle section 28 is moved axially in the distal direction. As a result, the inner sleeve 18, which is connected to the second handle portion 28, is also moved axially in the distal direction. This axial movement of the second handle portion 28 and the inner inner sleeve 18 is facilitated by the interaction of the projections 64 and collar 62 .

This axial movement of the second handle section 28 and the inner sleeve 18 relative to the first handle section 26 and the outer sleeve 12 brings the distal end 22 of the inner sleeve 18 into a position in which the puncture tip 24 of the outer sleeve 12 can be removed from the distal end 22 of the inner sleeve 18 is overlapped or covered.

In the second state, the two grip sections 26, 28 can be latched together via the latching lug 60 in order to prevent the cannula 10 from being unintentionally released from the second state.

In the second state, the corresponding catheter can be removed from the gap formed by the longitudinal cuts 32, 34 and 40, 42.

Claims

claims

A suprapubic cannula (10) for puncturing body cavities, comprising an outer elongate sleeve (12) having proximal and distal ends (14, 16) and an inner elongate sleeve (18) having proximal and distal ends (20, 22), wherein the inner sleeve (18) is blunt at its distal end (22) and the outer sleeve (12) at its distal end (16) has a puncture tip (24), wherein the proximal end (14) of the outer sleeve (12) with a first handle portion (26) and the proximal end (20) of the inner sleeve (18) is connected to a second handle portion (28), the first and second handle portions (26, 28) being threadably (30) so engaged with each other that the twisting of the two handle sections (26, 28) relative to one another transfers the cannula (10) from a first state to a second state, with the longitudinal section (34) of the inner sleeve (18) being in the first state of the cannula (10) is covered by the outer sleeve (12) un d the puncture tip (24) of the outer sleeve (12) is exposed for puncture and in the second state of the cannula (10) the longitudinal cuts (32, 34) of the inner and outer sleeve (12, 18) come to lie one above the other and the puncture tip ( 24) of the outer sleeve (12) is overlapped, preferably completely overlapped, by the distal end (22) of the inner sleeve (18).

2. Cannula (10) according to claim 1, wherein the two handle sections (26, 28) are releasably locked together in the first state and non-releasably locked together in the second state.

3. Cannula (10) according to one of the preceding claims, wherein the two handle sections (26, 28) each have a longitudinal section (40, 42) which is a continuation of the longitudinal section (32, 34) of the respective handle section (26, 28) connected sleeve (12, 18), and wherein in the second state of the cannula (10) the longitudinal cuts (32, 34) of the two handle sections (26, 28) come to lie on top of each other.

4. Cannula (10) according to any one of the preceding claims, wherein the first handle portion (26) has a proximal (35) and a distal end (37) and wherein the thread (30) by the shape of the proximal end (35) of the first Handle portion (26) is defined.

5. Cannula (10) according to claim 4, wherein the proximal end (35) of the first handle section (26) forms two helical sections (31, 33).

6. cannula (10) according to claim 5, wherein the second handle portion (28) has two bearing surfaces that can slide respectively on the two helical portions (31, 33).

7. Cannula (10) according to claim 5 or 6, wherein the two helical sections (31, 33) each have at least one locking lug (56, 58, 60).

8. Cannula (10) according to one of the preceding claims 5-7, wherein the two helical sections (31, 33) each have a collar (62) which extends at least partially along the respective helical section (31, 33), the collar (62) being configured to at least partially engage a portion of the second handle portion (28).

9. The cannula (10) according to any one of the preceding claims, wherein the first handle section (26) at least partially encloses the second handle section (28) in the first state and/or in the second state.

10. The cannula (10) according to any one of the preceding claims, wherein the second grip section (28) has at least one tab (38), preferably two tabs (38) arranged diametrically opposite one another, the tab (38) at least in regions along an outer surface of the first handle section (26), preferably essentially parallel to the longitudinal axis of the outer sleeve (12) and/or the inner sleeve (18).

The cannula (10) of claims 8 and 10, wherein the tab (38) includes at least one projection (64) adapted to engage the collar (62) of the first handle portion (26).

12. The cannula (10) according to any one of the preceding claims, wherein the distal end (22) of the inner sleeve (18) has an inwardly bent tongue (46).

13. Cannula (10) according to any one of the preceding claims, wherein the first grip portion (26) has a threading aid (49) for a catheter.

14. The cannula (10) according to claim 13, wherein the threading aid (49) is positioned in the first grip section (26) in such a way that in the first state of the cannula (10) it is on the side of the longitudinal cut (34) of the inner sleeve (18). is arranged.

15. The cannula (10) according to claim 13 or 14, wherein the threading aid (49) is at least partially deflectable and/or deformable, so that the second grip section (28) moves the threading aid (49) from the inner sleeve (18), preferably outwards, can at least partially deflect and/or bend.

16. Cannula (10) according to any one of claims 13 to 15, wherein the threading aid (49) in the second state of the cannula (10) with the second grip portion (28), preferably non-detachably, locked.

17. The cannula (10) according to any one of the preceding claims, which is designed in such a way that a complete turning back from the second state into the first state is prevented and wherein the inner sleeve (18) preferably expands in the second state, which allows turning back into makes the first state impossible.

18. Cannula (10) according to one of the preceding claims, wherein the transfer of the cannula (10) from the first state to the second state requires a relative rotation of the grip sections (26, 28) to one another of 90°-170°, preferably of 100°- 150° required.

19. Cannula (10) according to any one of the preceding claims, wherein the thread (30) has a thread pitch which is smaller in the area of the first state than in the rest of the thread (30), the thread (30) preferably in the area of the first state State is flat or has an opposite slope.

20. Kit with a cannula (10) according to one of the preceding claims and a catheter which can be accommodated in the inner sleeve (18) of the cannula (10), wherein the catheter in the second state of the cannula (10) through the superimposed longitudinal cuts ( 32, 34) of the sleeves (12, 18) can be removed from the cannula (10).