This summer, ValleyOrtho announced that Tomas Pevny, MD, had begun using an analgesic technique with the trade name iovera° to treat pain associated with total knee replacement (TKR) surgery. ValleyOrtho, based at Valley View Hospital (VVH) in Glenwood Springs, also has branch clinics in Aspen, Willits, Eagle and Silt. Dr. Pevny, who has been an orthopedic surgeon since 1995, is the first physician in the region to begin using the treatment.
As described in a VVH press release, iovera° is “an FDA-approved, non-surgical, non-opioid osteoarthritis knee pain treatment that uses extreme cold to temporarily stop nerves from sending pain signals.” It went on, “Administered with a non-surgical handheld device, iovera° is an innovative cryoanalgesia technology that allows healthcare providers to block pain for immediate and long-term relief by delivering precise cold therapy to a targeted nerve.”
In a discussion with The Sopris Sun, Dr. Pevny explained that iovera° treatment has been around for “about 10 years, but only in the past three or four years” has it been used to treat pain. Prior to that, the technology was used principally for cryoablation (tissue destruction using extreme cold), typically utilizing liquid nitrogen. The difference in the newer application is that it uses “warmer” liquid nitrous oxide (N2O) to temporarily damage nerves that will then grow back.
Nitrous oxide “boils” at about -88° C (-127° F), which is cold enough to block targeted nerves but not permanently destroy them. During the procedure, liquid nitrous is introduced into a closed-ended needle, where it is converted to gas and works with the body’s fluids near the point of the needle’s insertion to precisely freeze that specific nerve. No gas is injected into the body.
As Dr. Pevny explained, the treatment lasts “about three or four months,” during which time the nerve slowly grows back. He noted that the procedure targets only sensory nerves (those delivering pain signals to the brain) and “not motor nerves.” He went on to tell The Sun that although iovera° is being used increasingly to treat chronic pain in knees and other joints, he is “focused on surgery, especially TKR.”
“The first two weeks [after the surgery] can be uncomfortable for some patients,” he explained, and traditionally doctors have prescribed opioids, “with all of the negative aspects of that treatment.” He began doing research on alternatives to opioids and came upon iovera° and became “very interested” in it. He was quite surprised, however, that it “hadn’t become mainstream yet.” One reason for this, he suggested, was that the procedure takes some time (about half an hour) and may “disrupt the flow” of consultation schedules.
Over the past several months he has been administering an iovera° procedure about two weeks prior to the surgery, thus preemptively stopping the patient’s pain. After surgery, the patient then undergoes “multimodal pain management” that minimizes opioid use. Because the motor nerves are not targeted by iovera°, rehabilitation therapy is not affected. He noted that patients often “don’t even know it” when the nerves grow back; at that point they typically are pain-free.
So far, some 40 TKR recipients have gotten the procedure. Dr. Pevny and his colleagues are doing follow-up studies on them and future patients. He explained, “If we get good data, our goal will be to write a publishable peer-reviewed paper” in a medical journal. He noted that there are not many studies yet; “Anything we can contribute to the study [of iovera°] to make other physicians aware of it would be good.” He added, “We are on the leading edge [at VVH] with robotic technology, and we’re happy to support what we do in the OR [operating room] with technology like iovera°.”
More information on iovera° treatment can be found at www.ioverapro.com
Tomas Pevny, MD, courtesy photo