The present invention relates to medical instruments for ablating tissue, and in particular to a microwave probe for ablation of tumors and the like.
Microwave ablation (MWA), like radio frequency ablation (RFA), uses localized heating to cause tissue necrosis. However, MWA can produce greater and more rapid heating and can easily support the use of multiple probes because current flow between the probes can be limited. The mode of heating in MWA also eliminates ground pads and charring concerns.
Unfortunately, current MFA equipment produces relatively small lesions because of practical limits in power and treatment time. Power is limited by the current carrying capacity of the small gauge feeder line as it passes through the patient to the site of the necrosis. Larger feeder lines are undesirable because they are not easily inserted percutaneously. Heating of the feeder line at high powers can also lead to burns around the insertion point of the MWA probe.