High frequency surgical snare electrode

Claim 1

An improved high frequency surgical snare electrode instrument, particularly for endoscopes, of the type having a guide channel (1) with an outer peripheral surface that is at least externally insulated, an electrode lead (3) slidably displaceable in the guide channel, and a resilient snare electrode (5) attached to a free end of the electrode lead, capable of resiliently spreading apart when moved out of the guide channel and at least partially retractable into the guide channel by the electrode lead, said resilient snare electrode having first and second halves cooperatively defining a cutting loop portion used to surround a growth which is to be excised, the improvement comprising: said first and second snare electrode halves extending away from said cutting loop portion to define a cooling extension, said first and second halves engaged intimately along said cooling extension; and means maintaining said first and second halves intimately engaged along said cooling extension, said cooling extension being movable relative to said guide channel upon slidably displacing said electrode lead within said channel; said cooling extension increasing the heat capacity of said snare electrode, particularly at the cutting loop portion, to prevent failure of the snare occasioned by thermal stress.