Surgical scissors with bipolar coagulation feature

Abstract

A bipolar electrosurgical scissors for use in open or endoscopic surgery has a pair of opposed blade members pivotally joined to one another and to the distal end of the scissors itself by a rivet which extends through a insulated bushing member. Each of the blade members comprises a blade support and a blade itself, each fabricated from metal, such as stainless steel. The blades are affixed to their associated supports by means of a suitable adhesive or adhesive composite material such as a fiberglass reinforced epoxy exhibiting dielectric properties. Cutting is performed, steel-on-steel, without causing a short circuit between the two blade supports which themselves function as the bipolar electrodes.

Description

BACKGROUND OF THE INVENTION1. Field of the InventionThis invention relates generally to the design of a bipolar electrosurgical scissors, and more particularly to a surgical scissors incorporating bipolar electrodes as its blade elements, such that mechanical cutting with subsequent electrocoagulation can be achieved without requiring an instrument exchange.2. Discussion of the Prior ArtElectrocoagulating instruments include at least one conductive electrode. Radio frequency energy is conducted through this electrode to either a remote conductive body-plate (monopolar) or to a second, closely-spaced conductive electrode (bipolar). Current passing through the gap between the two electrodes will coagulate blood and other body fluids placed between them.Monopolar electrocautery instruments suffer from the fact that the return path between the active-electrode and the large area body-plate can be unpredictable as the electrical current seeks the return electrode through the path of leas...

AI Technical Summary

Benefits of technology

It has been found convenient in the manufacture of the scissors of the present invention to employ a partially cured epoxy, an epoxy impregnated fiberglass mat or a slurry of glass beads and epoxy as the bonding layer for joining the blades to their respective supports while maintaining a desired spacing therebetween. The partially cured epoxy can be die-cut to size so as to conform in shape to the interface between the blade support and the blade member. When the laminated structure is clamped together and then subjected to a heating operation, the epoxy spacer layer fully cures and creates a strong bond between the blade and its blade support, while still maintaining electrical isolation therebetween.

Problems solved by technology

Monopolar electrocautery instruments suffer from the fact that the return path between the active-electrode and the large area body-plate can be unpredictable as the electrical current seeks the return electrode through the path of least resistance.

With bipolar electrosurgical instruments, however, because the two electrodes are closely spaced to one another, usually at the distal end of an instrument handle, the return path is very short and only involves the tissue and fluids in the short path between the electrodes.

When using a mechanical cutting scissors of this type to excise tissue, when a blood vessel is cut, bleeding results.

This instrument exchange is time-consuming and in a surgical procedure where moments count, it would be desirable to have a scissors-type instrument for cutting but which also incorporates the ability to coagulate blood and other body tissue using RF energy.

To date, however, there is not available in the marketplace a bipolar electrosurgical scissors where its two blades are electrically isolated from one another and comprise the bipolar electrode pair.

With metal-to-metal contact along the sharpened edges of the two blades, an electrical short results.

Furthermore, the attempt to use a rivet or screw as the pivot point for the blades is another area where short-circuiting is likely to occur.

While that arrangement works well in implementing a bipolar electrosurgical scissors, the cost of manufacture is relatively high because of the difficulty in working with ceramics, especially when constructing electrosurgical scissors having arcuate blades.

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