Pain Therapy: When Ice Beats Fire

Physicians in the field of interventional pain management might want to look in hospital storage rooms for cryo machines that have fallen idle.

According to Andrea Trescot, MD, a pain specialist and board-certified anesthesiologist based in Wasilla, AK, ablating nerves responsible for pain by freezing them with a CO2 or nitrogen probe is a an old therapy that is coming back into its own. “Its ice versus fire,” she said, referring to procedures that essentially burn nerves to relieve pain.

Addressing colleagues at the annual meeting of the American Society of Interventional Pain Physicians in Orlando April 9, Trescot said that while the US Food and Drug Administration (FDA) is expected to approve a new version of the cryo machine, there are plenty of old ones out there that can be refitted with new tips and put into use.

The payoff, she said, is that cryo-ablation appears safer and more effective—and much easier on patients—than other procedures to remove pain such as that caused by entrapped nerves.

“It can also be used on large myelinated nerves,” she said. Though the treatment is not permanent, the nerve usually grows back normal and healthy and if a repeat procedure is needed, it can easily be done.

Another advantage, “It doesn’t kill or damage anything else,” she said, such as bone or adjacent tissue. The procedure starts with an injection of saline and epinephrine, but not anesthetic, she said.

To better locate the culprit nerve, she keeps patients conscious but lets them know the discomfort with the procedure lasts only 30 seconds.

Trescot said that while insurers may initially balk at payment, it is covered as a neurolytic procedure, one that uses a thermal means of destroying the nerve. When she practiced in Florida, she said, Blue Cross was refusing to pay, but “We beat them, and they pay now.”

She said she has been experimenting with using ultrasound instead of fluoroscopy to local the nerve.

In an interview after her presentation Trescot said there are no limits to the kinds of pain that could be treated with cryo-ablation. “It works head to toe,” she said.

Trescot is due to publish a book on using the procedure later this year.