WO2005094709A1

WO2005094709A1 - Bipolar clamp comprising a sealing layer

Info

Publication number: WO2005094709A1
Application number: PCT/EP2005/003068
Authority: WO
Inventors: Achim Brodbeck; Jürgen HILLER
Original assignee: Erbe Elektromedizin Gmbh
Priority date: 2004-03-22
Filing date: 2005-03-22
Publication date: 2005-10-13
Also published as: DE102005011869A1

Abstract

The invention relates to a bipolar clamp that is used for coagulating and/or cutting biological tissue and comprises the following: two clamp parts (12, 14) that are interconnected by means of a final screw or similar articulated joints (16); electrode parts (32, 34) with contact surfaces (32a, 34a) at distal ends (22, 24) of the clamp parts (12, 14) for grabbing the tissue and conducting a high-frequency current through the tissue; gripping devices (12a, 14a) at proximal ends (18, 20) of the clamp parts (12, 14), and power supply devices (15) for delivering the HF current to the electrode parts (32, 34). At least one surface of the distal ends (22, 24) is formed from an electrically insulating hard material (42, 44). The inventive clamp is further developed such that the distal ends are easy to clean even when being heavily soiled without damaging the instrument. For this purpose, one surface of the electrically insulating hard material (42, 44) is provided with a sealing layer.

Description

BIPOLAR CLAMP WITH SEALING LAYER

The invention relates to a bipolar clamp according to the preamble of patent claim 1.

Such bipolar terminals are known for example from DE 102 05 093 A. They essentially have two clamp parts which are connected to one another by means of a closing screw or similar articulated connections. Electrode parts for grasping tissue and for passing an HF current through the tissue are located at the distal ends of the clamp parts. Furthermore, grip devices for handling the clamp are provided at the proximal ends of the clamp parts. The RF current is supplied to distal ends of the clamp via current supply devices in order to introduce the current through the electrode parts into a body section of a patient.

Depending on the current density and thus the heat development caused by the HF current, a defined tissue area can be changed or destroyed by protein coagulation and dehydration. This means that the colloidal tissue components present in the sol state first change to the gel state, the now gel-shaped tissue components then further compacting with the escape of liquid. The tissue contracts so that the vessels are closed and bleeding stopped. An increase in the current density then causes the tissue fluid to evaporate explosively and the cell membranes to tear open, the tissue being completely severed.

The heat development does not only cause the desired coagulation or cutting effects. So burn z. B. tissue residues and blood at the distal ends of the electrosurgical instrument so strongly that they can only be cleaned with great effort, for example by means of mechanical cleaning measures. In this respect, the distal ends of known electrosurgical instruments are often made of a wear-resistant hard material, such as, for example, in areas which surround the electrodes. B. ceramics. This increases the stability of the distal ends, so that aggressive cleaning measures, for example using a steel brush, can be carried out.

Hard materials of this type can be freed of undesirable residues better than conventional materials because they have a higher wear resistance. However, due to microcracks and the associated high porosity, they are susceptible to contamination, in particular for liquids that penetrate the hard material and thus destroy the electrosurgical instrument. On the one hand, penetrating substances increase the porosity of the hard material, on the other hand, conductive substances in particular impair the insulating effect of the hard material. Once penetrated, substances can only be cleaned, if at all, with aggressive chemicals and / or under mechanical influence.

The invention is therefore based on the object of developing a bipolar clamp of the type mentioned at the outset such that the distal ends can be easily cleaned even in the case of severe contamination, without causing the instrument to be destroyed.

This object is achieved by a bipolar clamp according to claim 1.

In particular, the object is achieved by a bipolar clamp for coagulating and / or cutting biological tissue, which comprises the following: two clamp parts which are connected to one another by means of a closing screw or similar joint connections, electrode parts with contact surfaces at distal ends of the clamp parts for grasping the tissue and for Passing a high-frequency current through the tissue, handle devices at the proximal ends of the terminal parts, and current supply devices for supplying the HF current to the electrode parts. The distal ends are formed at least on one surface from an electrically insulating hard material, one surface of the electrically insulating hard material having a sealing layer. The distal ends can therefore be formed entirely from hard material or they only have a surface consisting of hard material. A core of the distal ends can then be made of metal, for example.

An essential point of the invention lies in the fact that the seal forms a smooth, dirt-repellent and nevertheless elastic surface on the hard material, so that burnt-on tissue residues and blood during an operation can be mechanically removed for cleaning purposes without damaging the distal ends. The elasticity of the sealing layer prevents it from being scratched and thus also prevents the hard material from being destroyed. Since the seal also seals the pores of the hard material, its porosity no longer comes into play. Penetration of substances, in particular liquids, into the hard material can thus be avoided. The sealing layer also increases the resistance of the distal ends to acids and alkalis.

A first preferred embodiment provides that the sealing layer is formed from a nanocomposite lacquer. Paints of this type have excellent mechanical properties, seal the pores of the underlying hard material or the underlying hard material layer and form a hydrophobic protective layer. The sealing lacquer can also be applied to the hard material layer using special application methods in such a way that the wear resistance of the hard material layer continues to be effective. The lacquers can preferably be designed such that they have anti-adhesive properties. This prevents tissue from caking at the distal ends due to enormous heating during the surgical procedure. In addition, other wear-resistant sealing layers can also be applied to the hard material layer. Polymer-based paints which have the properties required for electrosurgical instruments are particularly suitable.

In a further preferred embodiment, the electrically insulating hard material consists of a ceramic. Hard materials of this type advantageously have high corrosion resistance and high wear resistance. If the clamp is mechanically cleaned to remove burnt-on tissue residues and blood, for example with sandpaper or a steel brush, the hard material withstands the mechanical influences, so that damage to the clamp essentially occurs is avoidable. This is particularly advantageous if - as already mentioned above - the sealing layer is applied to the hard material using a special application method in such a way that the wear resistance of the hard material continues to be effective.

The ceramic preferably consists of aluminum or zirconium oxide. In addition to its high wear resistance, aluminum oxide has a high chemical resistance. In this respect, the coating is resistant to cleaning agents or disinfectants. Zirconium oxide has a low thermal conductivity, so that burning of tissue remnants and blood is already counteracted while the bipolar clamp is being used.

If the electrode parts also have a layer made of an electrically conductive, high-strength alloy at the distal ends, the electrode parts can also be protected against wear. Both during use and during cleaning, the electrode parts are resistant to mechanical stress or chemical influences due to the high-strength alloy.

In a further preferred embodiment, the electrically conductive, high-strength alloy of the electrode parts is a hard aluminum alloy. This preferably combines high electrical conductivity with high strength, so that burnt-on tissue residues and burnt-on blood can be removed mechanically without any problems, particularly in these areas.

The contact surface of at least one electrode part is preferably structured to improve slip resistance. For example, tissue has to be gripped and also moved with the clamp. A structured contact surface allows the clamp to engage securely in the tissue, while at the same time preventing it from slipping. This is particularly advantageous if the operation site is not or only partially visible and a necessary re-picking up of the tissue would be difficult.

A solution according to the invention provides that the electrode parts on the distal ends of the terminal parts on the respective contact surfaces are complementary to one another Have structure. When the clamp is closed, the electrode parts are separated from each other by a uniform gap. The structuring of the two opposing contact surfaces additionally reduces the risk of the tissue once slipping away. In addition, the complementary structuring allows the formation of a uniform gap between the electrode parts, so that an undesired short circuit can be avoided if the contact surfaces are brought together accidentally.

The structuring is preferably essentially undulating. This makes the contact surfaces easy to clean, for example with a steel brush, because the soft transitions between mountain and valley do not form any edges or corners

This would promote the establishment of dirt and make access more difficult during cleaning.

Alternatively, it is possible to provide the structuring as a waffle pattern, the square or diamond-shaped surfaces being delimited with only slightly raised intermediate walls. In this way, too, an improved grip and, at the same time, easy cleaning can be achieved due to the small difference in level between the surfaces and the walls.

Further embodiments of the invention emerge from the subclaims.

The invention is described below using exemplary embodiments which are explained in more detail with reference to the figures. Show here

1 shows a first embodiment of the invention in a perspective partial view;

2 shows a second embodiment of the invention in a perspective partial view;

3 shows a third embodiment of the invention in a partial perspective view; Fig. 4 is a fully illustrated bipolar clamp according to the second embodiment in a perspective view.

In the following description, the same reference numbers are used for the same and equivalent parts.

As shown in FIG. 1, a bipolar clamp 10 comprises two clamp parts 12, 14, which are pivotally connected to one another near an distal ends 22, 24 of the respective clamp parts 12, 14 via an articulated connection 16. The distal ends 22, 24 of the clamp parts 12, 14 have electrically conductive electrode parts 32, 34, which are used on the one hand to grip tissue and on the other hand to conduct a high-frequency current through the tissue. For this purpose, the electrode parts 32, 34 are preferably made of metal. In the embodiment shown here, the distal ends 22, 24 of the clamping parts 12, 14 have an electrically insulating hard material layer 42, 44, which in turn is formed with a sealing layer 46, 48. So that means the

Hard material layer 42, 44 itself is again coated with sealing layer 46, 48. Alternatively, it is possible that the distal ends not only have a hard material layer, but are made entirely of hard material. For example, a core of the distal ends can then be formed from metal.

High-frequency electrical current is supplied to the electrode parts 32, 34 via (not shown) electrical lines. During the treatment of the tissue with the HF current, tissue remnants and blood burn at the distal ends 22, 24 due to heating by the electrical current. Subsequent cleaning of the bipolar clamp 10 is difficult insofar as the distal ends 22, 24 usually have to be subjected to high mechanical stresses for an optimal cleaning result, for example with sandpaper or wire brush or also by means of aggressive cleaning agents. The mechanical stress during cleaning causes damage to the distal ends 22, 24. In this embodiment, the distal ends 22, 24 therefore have the abrasion and wear-resistant coating 42, 44 mentioned above, ie the electrically insulating hard material layer. A further improvement in the wear resistance of the distal ends 22, 24 is ensured by sealing this hard material layer by means of the sealing layer 46, 48. For example, a ceramic such as zirconium oxide or aluminum oxide is used as the electrically insulating hard material layer 42, 44. In addition to its high wear resistance, aluminum oxide has a high chemical resistance. In this respect, the coating is resistant to cleaning agents or disinfectants. Zirconium oxide also has a high wear resistance and also a low thermal conductivity. Burning of tissue residues and blood is thus counteracted during the treatment.

The sealing layer 46, 48, which preferably completely surrounds the hard material layer 42, 44, enables u. a. the sealing of microcracks or pores of the hard material layer 42, 44. The porosity of the hard material layer also means that cleaning agents penetrate the layer in the cleaning measures described above and destroy it from the inside. But not only cleaning agents, body fluids or similar substances penetrate into the pores, especially during a surgical procedure. A simple mechanical cleaning is then no longer possible. Aggressive chemical cleaning agents must be used here to remove the contaminants. Wetting or soaking the hard material layer with liquids is also disadvantageous because they can contain freely moving ions and thus cause a current to flow. This would conflict with the required electrically insulating property of the hard material layer.

The sealing layer 46, 48 is preferably provided as a wear-resistant lacquer. In principle, any lacquer, for example a polymer-based lacquer, which has the properties required for electrosurgical instruments, is suitable for this. So-called nanocomposite paints can be used, for example, to achieve extremely smooth, dirt and water-repellent surface coatings in addition to sealing the pores. Special application methods allow the wear-resistant effect of the hard material layer to continue to be felt under the lacquer layer. The sealing layer preferably has non-stick properties, so that burn-in of tissue and blood during a surgical intervention is prevented or at least significantly reduced.

Fig. 2 shows a second embodiment of the invention. The partial view of the bipolar clamp 10 is similar to that shown in FIG. The only difference is that in this embodiment also the electrode parts 32, 34 a layer 52, 54 consisting of an electrically conductive, high-strength alloy, such as. B. have a hard aluminum alloy. This ensures both the electrical conductivity and the abrasion and wear resistance of the electrode parts 32, 34.

3 shows a third embodiment of the object according to the invention, contact surfaces 32a, 34a of the electrode parts 32, 34 being structured. In this exemplary embodiment, the structuring is essentially wave-shaped.

The structuring improves the slip resistance of the electrode parts 32, 34 serving as the gripping surfaces if, for example, tissue is to be gripped and moved with them. A secure hold is particularly advantageous when the surgeon has only a limited view of the operating area and it is difficult to pick up a slipped tissue again.

Since the electrode parts 32, 34 must be separated from one another by a uniform gap when the terminal 10 is closed, in order to prevent a possible short circuit, the uniform gap width can be achieved in particular via a complementary structure. The structuring of the two opposing contact surfaces 32a, 34a additionally reduces the risk of the tissue once detached from slipping off.

The structure in the form of a ween allows for easy cleaning of the electrode parts 32, 34 or the contact surfaces 32a, 34a, because the soft transitions between the mountain and the valley facilitate access for any cleaning agents.

As an alternative, the structuring in the form of a waffle pattern offers an improved slip resistance of the electrode parts 32, 34 while at the same time being easy to clean. As a rule, in the case of a waffle pattern, square or diamond-shaped areas are delimited from one another by slightly raised intermediate walls. The slight difference in level between surfaces and walls allows easy access for mechanical cleaning, for example with sandpaper or a steel brush. FIG. 4 shows a completely shown bipolar clamp 10, corresponding to the embodiment shown in FIG. 3. Also visible here are handle parts 12a, 14a at respective proximal ends 18, 20 of the clamp parts 12, 14. Power supply devices 15 are provided on the grip part 12a of the clamp part 12. These are used to connect the electrosurgical instrument to an HF generator (not shown), which generates the high-frequency electrical current. The current is supplied to the electrode parts 32, 34 via the current supply devices 15, an electrical line 15a leading from the HF generator to the current supply devices 15 and the electrical lines (not shown) running through the terminal 10.

At this point, it should be pointed out that all the parts described above are seen separately and in any combination, in particular the details shown in the drawings, are claimed as essential to the invention. Modifications are familiar to the person skilled in the art.

LIST OF REFERENCE NUMBERS

10 Bipolar clamp 12 clamp part 14 clamp part 12a grip part 14a grip part 15 power supply devices 15a electrical line 16 articulated connection 18 proximal end of a clamp part 20 proximal end of a clamp part 22 distal end of a clamp part 24 distal end of a clamp part 32 electrode part 34 electrode part 32a contact surface 34a contact surface 42 Electrically insulating hard material, electrically insulating hard material layer

44 Electrically insulating hard material, electrically insulating hard material layer

46 Sealing layer 48 Sealing layer 52 Electrically conductive, high-strength layer 54 Electrically conductive, high-strength layer

Claims

claims

1. Bipolar clamp for coagulating and / or cutting biological tissue, comprising - two clamp parts (12, 14) which are connected to one another by means of a closing screw or similar joint connections (16), - electrode parts (32, 34) with contact surfaces (32a, 34a ) at distal ends (22, 24) of the clamp parts (12, 14) for grasping the tissue and for passing a high-frequency current through the tissue, - grip devices (12a, 14a) at proximal ends (18, 20) of the clamp parts (12, 14), - Power supply devices (15) for supplying the HF current to the electrode parts (32, 34), the distal ends (22, 24) being formed at least on one surface from an electrically insulating hard material (42, 44) characterized in that a surface of the electrically insulating hard material (42, 44) has a sealing layer (46, 48).

2. Bipolar clamp according to claim 1, characterized in that the sealing layer (46, 48) is formed from a nanocomposite lacquer.

3. Bipolar clamp according to claim 1 or 2, characterized in that the electrically insulating hard material (42, 44) consists of a ceramic.

4. Bipolar clamp according to one of the preceding claims, in particular according to claim 3, characterized in that the ceramic consists of aluminum or zirconium oxide.

5. Bipolar clamp according to one of the preceding claims, characterized in that the electrode parts (32, 34) at the distal ends (22, 24) have a layer consisting of an electrically conductive, high-strength alloy (52, 54).

6. Bipolar clamp according to one of the preceding claims, in particular according to claim 5, characterized in that the electrically conductive, high-strength alloy (52, 54) is an H-t-rt-ύumi-itim alloy.

7. Bipolar clamp according to one of the preceding claims, characterized in that the contact surface (32a, 34a) of at least one electrode part (32, 34) is structured to improve slip resistance.

8. Bipolar clamp according to one of the preceding claims, characterized in that the electrode parts (32, 34) at the distal ends (22, 24) of the clamp parts (12, 14) on the respective contact surfaces (32a, 34a) have a complementary structure have so that when the clamp is closed the electrode parts (32, 34) are separated from one another by a uniform gap.

9. Bipolar clamp according to one of the preceding claims, in particular according to claim 7 or 8, characterized in that the structuring is substantially wave-shaped.