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The Deep Freeze for GI Tumors
Anthony Kalloo uses extreme cold to get rid of the lesions.


The Deep Freeze for GI Tumors

Cryotherapy, the use of extreme cold to freeze and get rid of unwanted tissue, has for some time worked well in destroying lesions of the skin, liver and kidneys. But the freezing technique still hasn’t been used on tumors in the gastrointestinal tract, mainly because surgeons use an endoscope to visualize the inside of the body and there has been no cryotherapy delivery system that is thin, long and flexible enough to be passed through that surgical instrument. What’s more, traditional liquid-nitrogen-based cryotherapy posed the threat of freezing the endoscope itself.

Now, a novel delivery system developed by Hopkins and Rockville, Md., instrument maker Cryomedical Sciences has made cryotherapy a logical treatment for GI cancers. The delivery device works by using compressed gas rather than liquid nitrogen to cause a hypothermic injury to a tumor up to 2 to 3 mm deep. Because the gaseous expansion occurs only at the very tip of the probe, the catheter remains warm, but the freezing of the tumor occurs in seconds, and tissue begins to slough off within a day. Also, because the gas is sprayed in quick bursts and doesn’t come in contact with other tissue, there is less chance of perforating the GI tract than with other types of treatment.

“Potentially, this cryotherapy device could be used for the removal of superficial lesions in the esophagus, debulking and easing large tumors in the gut, and arresting the bleeding in lesions,” says gastroenterologist Anthony Kalloo, M.D., who is now trying the method on patients in a clinical trial.

—- GL