An electrosurgical apparatus for coagulating tissue includes an elongated
flexible tube having a proximal end, a distal end and a source for
supplying pressurized ionizable gas to the proximal end of the tube. The
apparatus also includes a hollow sleeve made from a shape memory alloy
having a generally curved austenite state and displaying stress-induced
martensite behavior. The hollow sleeve is restrained in a deformed
stress-induced martensite configuration within the tube and partial
extension of a portion of the hollow sleeve from the tube transforms the
portion of the sleeve from the deformed configuration to the generally
curved austenite configuration such that the gas is directed transversely
at the tissue. An electrode ionizes the gas in the region between the
sleeve and the tissue. Other embodiments of the present disclosure also
include a wire connected to the distal end of the tube which movable from
a first postion wherein the tube is disposed in a generally rectilinear,
parallel fashion relative to the tissue to a second retracted position
wherein the distal end of the tube flexes at an angle to direct the gas
towards the tissue. Still other embodiments of the present disclosure
include a corona electrode for inducing ignition of the gas.