DE20110491U1 - Access cannula for endoscopic operations, especially for arthroscopy - Google Patents

Description

WITTE, WELLER & PARTNER

Patent attorneys

Rotebühlstraße 121 · D-70178 Stuttgart

Applicant:

Karl Storz GmbH & Co. KG Mittelstrasse 8
D-78532 Tuttlingen

Germany

19 June 2001 4613G133 WW-sp

Intake cannula for endoscopic operations, especially for arthroscopy

The invention relates to an access cannula for endoscopic operations, in particular for arthroscopy.

Access cannulas for endoscopic operations are well known.

In minimally invasive surgical techniques, which are becoming increasingly widespread, such access is achieved via a trocar. A trocar has a sleeve- or cannula-shaped, hollow tube-shaped body that is inserted into the body, for example through the abdominal wall, in order to carry out operations in the inner abdominal cavity. Appropriate instruments and in particular endoscopes are then passed through the trocar in order to be able to visually observe the operation being carried out inside the body.

To insert the trocar, a sharpened trocar mandrel or stylet is inserted into the trocar sleeve and a skin incision is made to insert the access cannula, in this case the trocar sleeve, into the body.

In minimally invasive operations on soft tissue, such as through the abdominal wall, the trocar can be inserted immediately in the required size.

It is much more difficult to create access for arthroscopic procedures. If you want to perform a minimally invasive endoscopic operation on a joint, the spaces between two bones that form a joint are often very small, so that a trocar cannot be easily inserted using the technique described above.

It is often desirable or even necessary to place several access cannulas in the surgical field in order to either observe the surgical field from several directions or to gain access to the joint from several directions.

Another problem is that gases and/or liquids are fed through the access cannula to improve visibility at the surgical site, in order to slightly expand the body in the surgical field using excess pressure. Irrigation fluids are also often fed through the access cannula. To prevent body fluids, gases or irrigating fluids from leaking out of the proximal end of the access cannula, there is usually a valve there, which on the one hand ensures that the cannula tube is sealed tightly, but on the other hand also makes it possible to push instruments or endoscopes through the valve. Different designs of valves with flaps or with slotted seals are known for this purpose.

Due to the previously mentioned widespread use of minimally invasive surgery, a large number of access cannulas are required, which then have to be cleaned and sterilized after the operation, which requires high-quality materials.

It is therefore an object of the present invention to provide an access cannula for endoscopic operations which enables different surgical methods and different possibilities for inserting the cannula and which can be produced cost-effectively, but nevertheless works effectively and safely during the procedure.

According to the invention, the object is achieved by an access cannula which has a cannula tube and a valve body, wherein the valve body is detachably connectable to one end of the cannula tube, and wherein the valve body has a valve,

·
•«Φ ··

which ensures a tight seal at the end of the cannula tube, but still allows instruments to be passed through the cannula tube.

It is now possible to combine different cannula tubes with one and the same valve body, which are best suited to the respective surgical technique. At the same time, this opens up the possibility of first inserting only the cannula tube and only later attaching the valve body to it. This also makes it possible to insert several cannula tubes close together, which are very slim, without the relatively bulky valve body being present at the same time. This provides a very high level of flexibility. Only when the actual operation is carried out, i.e. after preparation by inserting the access cannula, can the valve body be connected to the cannula tube, thus ensuring a tight seal at this end of the cannula tube. The instruments, for example endoscopes or surgical instruments, can then be pushed through the valve body itself.

Increased flexibility is also provided by the fact that other instruments can be attached to the cannula tube for a short time. To do this, the valve body is simply removed and an instrument, e.g. an observation optic or the like, can be attached for a short time.

It is therefore also possible to attach different cannula tubes to a single type of valve that has certain standard connections for other instruments, depending on the task and surgical technique.

This not only increases flexibility but also significantly reduces costs and ensures perfect sealing. The type of detachable connection between the base body and the cannula tube can be made in different ways, e.g. by screw connection, bayonet lock, snap connection, etc.

In a further embodiment of the invention, the valve body is designed as a sterilizable, reusable component.

This measure has the advantage that the previously mentioned dual design opens up the possibility of producing the valve body as a high-quality part, for example from medical steel, which can be sterilized and used multiple times.

In a further embodiment of the invention, the cannula tube is designed as a disposable component.

This measure has the advantage, particularly with the previously mentioned measure, that the cannula tube can be manufactured as a cost-effective disposable part for single use, to which the reusable valve body can then be coupled.

In a further embodiment of the invention, the valve is designed as a double-disk valve.

This measure has the advantage that the double-pane construction means that an instrument has to be passed through two panes, which ensures a particularly secure seal.

In a further embodiment of the invention, a slot seal is present in each pane.

This measure has the advantage that instruments with different diameters can be passed through, while ensuring a tight seal in each case. This is particularly the case because the valve is designed as a double-disk valve.

In a further embodiment of the invention, the slots are star-shaped and the slots of the two disks are rotated relative to each other.

This measure further contributes to the excellent tight seal.

In a further embodiment of the invention, the two discs are connected to each other via an elastic web.

This measure has the considerable advantage that the double disc valve consists of only one component.

In a further embodiment of the invention, locking means are provided on the disks by means of which the disks can be locked together.

This measure has the advantage that the double disc valve can be manufactured as a body extending in a plane, in which the two discs are connected to each other via the web and are placed over and on top of each other for assembly by bending the web and are then held firmly together by the locking means.

In a further embodiment of the invention, the valve body is formed in two parts, and the valve can be inserted between the two parts.

This measure has the advantage that the valve is held in the valve body by simple structural measures. This measure also allows the valve body to be easily dismantled for cleaning and sterilization.

In a further embodiment of the invention, the valve body has a base body which has an attachment for detachable connection to the cannula tube and which further has a recess into which the valve can be inserted, wherein the valve can be fixed via a clamping ring.

This measure has the advantage that the valve body and clamping ring can be made of high-quality stainless steel materials, whereas the valve in between can be formed by a disposable part. Therefore, only these two parts need to be sterilized; after sterilization, a new valve can be inserted.

This further increases flexibility and also helps reduce costs. In this case, both the cannula tube and the valve can be designed as disposable parts and only the two-part valve body can be made from high-quality and precisely manufactured materials.

In a further embodiment of the invention, the cannula tube has a ring on the distal side that widens conically towards the proximal side.

This measure has the advantage that the cannula tube can be pushed or pressed into the joint through this ring, especially during arthroscopic operations, and is secured against being pulled off or accidentally released during the operation, since the distal tip is virtually snapped into the joint with the conical ring.

In a further embodiment of the invention, the cannula tube is designed as a component of a trocar device.

This measure has the advantage that it allows a flexible kit of different trocars, for example for adults, for children, for thin and for obese people.

In a further embodiment of the invention, the trocar device has a mandrel with a handle including a stylet, wherein the mandrel including the stylet can be inserted into the cannula tube.

This measure has the advantage that the access cannula is designed as a trocar sleeve, which is inserted into the body together with the mandrel and the stylet.

In a further embodiment of the invention, the cannula tube is designed as a component of a dilatation device.

This measure has the considerable advantage that dilatation can be carried out without traumatization during access. For example, in arthroscopic operations, an initial access is initially achieved using very thin cannulas, this is widened by pushing on dilatation mandrels of increasing diameter, and finally the access cannula according to the invention is inserted as a cannula that remains in the body for the operation.

Particularly advantageously, the dilatation device has a puncture needle, a guide wire, and at least one dilatation mandrel for attachment to the guide wire, the cannula tube being designed such that it can be pushed onto a dilatation mandrel.

This arrangement is particularly advantageous for the atraumatic placement of the cannula tube for arthroscopic surgery, where this flexibility has a particularly beneficial effect. The guide tube can then be pushed back onto the dilatation mandrel using the mandrel with a handle.

It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

The invention is described and explained in more detail below using some selected embodiments in conjunction with the accompanying drawings. They show:

Fig. 1 is an exploded longitudinal section of an access cannula according to the invention, consisting of a cannula tube and a valve body;

Fig. 2 shows a section through the valve body rotated by 90° around the cannula tube axis;

Fig. 3 is a perspective view of the valve installed in the valve body;

Fig. 4 shows the double disc valve shown in Fig. 3 in an unfolded state before assembly in the valve body;

Fig. 5 is a corresponding perspective view of the valve rotated by 180°;

Fig. 6 shows a longitudinal section of the assembly consisting of cannula tube and valve body, corresponding to Fig. 1;

:■·&igr; &igr; in

·

Fig. 7 a mandrel with handle of a trocar device;

Fig. 8 shows a stylet of a trocar device intended to cooperate with an access cannula according to the invention of Fig. 6;

Fig. 9 shows an assembly of the components shown in Fig. 6, 7 and 8;

Fig. 10 a puncture needle of a dilatation device;
Fig. 11 an inner part of the puncture needle of Fig. 10;

Fig. 12 a guide wire which can be inserted into the puncture needle of Fig. 10;

Fig. 13 a dilatation mandrel and handle that can be pushed over the guide wire of Fig. 12; and

Fig. 14 shows an assembly of the access cannula of Fig. 1 or 6 with a mandrel of Fig. 7 inserted therein to be pushed over the dilatation mandrel of Fig. 13.

An access cannula shown in Fig. 1 is provided in its entirety with the reference number 10.

The access cannula 10 consists of a cannula tube 12 and a valve body 14.

The cannula tube 12 has a tube 16, at the distal end of which there is a conical ring 18 as a nose. The conicity is selected such that the ring 18 widens from distal to proximal.

Therefore, a shoulder 20 is created at a distance from the distal end. This ring 18 serves to be driven into a body opening, for example into a joint, and then to lock into place in order to prevent the cannula tube 12 from being pulled out.

In the area of the conical ring 18, a continuous opening 22 is provided on the side of the wall, which serves to enable pressure equalization with the environment during operations. At the end 23 opposite the conical ring 18, the tube 16 is provided with a larger diameter collar 24 which has an internal thread 26.

The valve body 14 has a base body 28, from one side of which a tubular extension 30 projects, which is provided with an external thread 32. The external thread 32 is designed in such a way that it can be screwed into the internal thread 26 in the collar 24 of the tube 16. The clear inner diameter of the extension 30 corresponds to the clear inner diameter of the tube 16. A nozzle 34 projects laterally from the base body 28 and is closed by a cap 36. This lateral nozzle 34 serves to supply liquids or gases to the tube 16 from the side via the valve body 14 or to drain them from the latter.

A valve 40 is arranged in the valve body 14, specifically on the proximal side of the lateral nozzle 34. The valve 40 thus ensures a tight closure of the valve body 14 in the proximal direction or of the cannula tube 12 when the valve body 14 is connected to it via the screw connection.

The valve 40 consists of a double disc valve 42, as can be seen in particular from Figs. 2 to 5.

The double disc valve 42 has two discs 44 and 46, each surrounded by a ring 45 or 47. A three-beam star-shaped slot 48 or 50 is provided in each disc 44 or 46. The material of the double disc valve consists of a rubber-elastic plastic material, so that despite the presence of the slots 48 and 50, a tight seal is ensured by each disc 44 or 46.

The two rings 4 5 and 4 7 are connected to one another via a flexible web 52. From the perspective representations of Fig. 4 and 5 it can be seen that the slots 48 and 50 are cut in a twisted manner with respect to one another.

As can be seen in particular from Fig. 4, a pin 54 projects from each disc and can be inserted into a corresponding opening 56 on the other disc.

The double disc valve 4 2 can thus be produced as a molded or stamped part in the orientation shown in Fig. 4 and 5, and is then brought into the position shown in Fig. 3 by bending it around the web 52.

The valve 40 is placed in a recess 58 in the base body 28 of the valve body 14, which has a lateral slot opening 60 from which the folded-over web 52 can protrude laterally. The valve 40 is held on the valve body 14 by a clamping ring 62, which is provided with an external thread for this purpose, which can be screwed into an internal thread (not shown in detail here) in the recess 58. The clamping ring 62 then presses the two rings 45 and 47 of the disks 44 and 46 onto one another in a sealing manner, so that, as a whole, the valve 40 ensures a tight seal on the valve body 14.

A continuous opening 64 is provided in the interior of the valve body 14, the clear inner diameter of which is larger than the clear inner diameter of the tube 16, so that instruments, such as endoscopes or the like, can then be attached to the valve body 14.

In Fig. 6, the access cannula 10 is shown in the assembled state, i.e. the valve body 14 is fully assembled, i.e. the valve 40 is inserted, and the valve body 14 is screwed via its external thread 32 on the attachment 30 into the internal thread 26 on the collar 24 of the cannula tube 12.

In this state, the access cannula 10 can now, for example, be a component or part of a trocar device 70, as shown in Figs. 7 and 8.

The trocar device 70 thus has a mandrel 72 and a stylet 73 which has a sharpened tip 74.

The mandrel 7 2 has a handle 7 8 from which a tubular sleeve 7 6 projects.

The outer diameter of the sleeve 76 is selected so that it corresponds to the clear inner diameter of the tube 16 of the access cannula 10.

The trocar device 70 is shown in its assembled state in Fig. 9, i.e. the stylet 73 is inserted into the sleeve 76 of the mandrel 72, and this assembly is in turn inserted into the cannula tube 12.

From the illustration in Fig. 9 it can be seen that the tip 74 slightly projects beyond the sleeve 76, which in turn projects beyond the conical ring 18 and is provided with a corresponding conical bevel. This creates a pointed conical driving end of the trocar device 70.

When the access cannula 10 is inserted, which now functions as a trocar sleeve, the stylet 73 is placed on a skin incision and inserted into the body, and the entire assembly of Fig. 9 is driven into the body to the desired depth. The handle 78 facilitates this process. The mandrel 72 and stylet 73 are then removed. Due to the valve body 14 with the closed valve 40, it is impossible for body fluids or the like to escape.

It is also possible to first insert the cannula tube 12 into the body without the valve body 14 and only then screw on the valve body 14.

It is also possible, as previously described, to drive in the assembly as shown in Fig. 6 and, after removing the mandrel 72 and stylet 73, to briefly unscrew the valve body 14 if necessary, for example to place a second access cannula in the immediate vicinity.

This makes the flexibility particularly clear.

After removing the access cannula 10, the valve body 14 can be disassembled, cleaned and sterilized, whereby, depending on the design, the double disc valve 42 can also be cleaned and reinserted or replaced by another one.

Depending on the design, the cannula tube 12 can also be cleaned and sterilized, or it can be designed as a disposable part and discarded after the operation. The cleaned, sterilized and reassembled valve body 14 can then be reconnected to a cannula tube 12.

Figures 10 to 14 show another possible use of the access cannula 10 according to the invention, which is an access for an arthroscopic operation, for example an operation on a shoulder joint. For this purpose, the puncture needle 82 shown in Figure 10 is placed at the point where access is desired between two joint bones. The diameter of the puncture needle 82 is extremely small and is in the range of approximately 1.5 mm.

The needle is pushed through the skin into the joint until the needle tip can be seen through an arthroscope.

The puncture needle 82, which is designed as a hollow needle, contains an inner part 84.

After inserting the puncture needle 82 into the joint, the inner part 84 is removed and a guide wire 86 is completely inserted into the puncture needle 82.

The puncture needle 82 is then removed and the guide wire 84 is now inserted into the body or joint.

After making a skin incision, a dilatation mandrel 88 is pushed onto the guide wire 86, which is connected to a handle 92 as shown in Fig. 13. The connection between the handle 92 and the dilatation mandrel 88 is made via a locking screw 94. Depending on the diameter to be expanded, one or more dilatation mandrels 88 of increasing diameter are pushed on.

In the embodiment shown, initially only the dilatation mandrel 88 is pushed onto the guide wire 86 and pressed into the joint, which is facilitated by the conical tip of the dilatation mandrel 88.

The outer diameter of the dilatation mandrel 88 corresponds to the clear inner diameter of a sleeve 76 of a mandrel 72, which in turn is inserted into the tube 16 of an access cannula 10 according to the invention.

"&Ggr; VI U .{.

This assembly is shown in Fig. 14.

After setting the dilatation mandrel 88, the handle 92 is removed by loosening the locking screw 94, and the assembly of Fig. 14 is pushed over the dilatation mandrel 88. The access cannula 10 is pushed in again until its conical ring 18 has snapped or locked into the joint. Considerable forces must be applied in this process, and the handle 78 enables this to be done in a safe manner, particularly due to its non-slip shape.

The dilatation mandrel 88 and the mandrel 72 are then removed, and only the access cannula 10 shown in Fig. 6 remains in the body. The actual surgical procedure can then be carried out by passing the appropriate instruments through.

Claims (16)

1. Access cannula for endoscopic operations, in particular for arthroscopy, with a cannula tube ( 12 ) and with a valve body ( 14 ), wherein the valve body ( 14 ) is detachably connectable to one end ( 23 ) of the cannula tube ( 12 ), wherein the valve body ( 14 ) has a valve ( 40 ) which ensures a sealing closure of the cannula tube ( 12 ) at the end ( 23 ), but enables instruments to be passed through the cannula tube ( 12 ). 2. Access cannula according to claim 1, characterized in that the valve body ( 14 ) is designed as a sterilizable, reusable component. 3. Access cannula according to claim 1 or 2, characterized in that the cannula tube ( 12 ) is designed as a disposable component. 4. Access cannula according to one of claims 1 to 3, characterized in that the valve ( 40 ) is designed as a double-disk valve ( 42 ). 5. Access cannula according to claim 4, characterized in that a slot seal is present in each disc ( 44 , 46 ) of the double disc valve ( 42 ). 6. Access cannula according to claim 5, characterized in that slots ( 48 , 50 ) of the slot seal are star-shaped, and that the slots ( 48 , 50 ) of the two disks ( 44 , 46 ) of the double disk valve ( 42 ) are rotated relative to one another. 7. Access cannula according to claim 5 or 6, characterized in that the two discs ( 44 , 46 ) are connected to one another via an elastic web ( 52 ). 8. Access cannula according to one of claims 5 to 7, characterized in that locking means are provided on the disks ( 44 , 46 ), by means of which the disks ( 44 , 46 ) can be locked together. 9. Access cannula according to one of claims 1 to 8, characterized in that the valve body ( 14 ) is designed in two parts, and that the valve ( 40 ) can be attached between the two parts ( 28 , 62 ). 10. Access cannula according to claim 9, characterized in that the valve body ( 14 ) has a base body ( 28 ) which has an attachment ( 30 ) for detachable connection to the cannula tube ( 12 ) and further has a recess ( 58 ) into which the valve ( 40 ) can be inserted, wherein the valve ( 40 ) can be fixed via a clamping ring ( 62 ). 11. Access cannula according to one of claims 1 to 10, characterized in that the cannula tube ( 12 ) has a proximally conically widening ring ( 18 ) on the distal side. 12. Access cannula according to one of claims 1 to 11, characterized in that the cannula tube ( 12 ) is designed as a component of a trocar device ( 70 ). 13. Access cannula according to claim 12, characterized in that the trocar device ( 70 ) has a mandrel ( 72 ) with a handle ( 78 ) together with a stylet ( 73 ), wherein the mandrel ( 72 ) can be inserted into the cannula tube ( 12 ). 14. Access cannula according to one of claims 1 to 11, characterized in that the cannula tube ( 12 ) is designed as a component of a dilatation device ( 80 ). 15. Access cannula according to claim 14, characterized in that the dilatation device ( 80 ) has a puncture needle ( 82 ), a guide wire ( 86 ) and at least one dilatation mandrel ( 88 ) for placement on the guide wire ( 86 ), wherein the cannula tube ( 12 ) is designed such that it can be pushed onto a dilatation mandrel ( 88 ). 16. Access cannula according to claim 15, characterized in that the cannula tube ( 12 ) can be pushed onto the dilatation mandrel ( 88 ) by means of a mandrel ( 72 ) provided with a handle ( 78 ).