Is Cryo the Analgesic Answer for Fewer Risks and Shorter Recovery Times?

Q&A with Dr. Harsha Shanthanna, clinician scientist and an expert in pain management.

Cryoanalgesia has been gaining popularity in recent years in the surgical field thanks to its effectiveness in relieving pain while remaining minimally invasive. As more medical professionals become familiar with this technique, it’s likely that cryoanalgesia will continue to grow in popularity as an option for pain management during outpatient surgery procedures.

To learn more about cryoanalgesia, we sat down with Harsha Shanthanna, MD, MSc, PhD, FRCPC, FIPP, EDRA, associate professor and anesthesiologist at McMaster University, Hamilton, Ontario, Canada, and chair of Interventional SIG for the Canadian Pain Society, to talk more about what his research has found about the technique, its benefits and if it’s worth introducing at your facility.

To start, can you tell us more about what cryoanalgesia is and how it is used in surgery?
Cryoanalgesia — also known as cyroablation or cryotherapy — is a medical technique that involves using extreme cold to numb nerves and provide pain relief. This is something of a historical technique since cold temperatures have been used for centuries to relieve pain. The cold impacts the nerve function’s ability to work efficiently, which is actually a good thing when you’re thinking of how it relates to a nerve’s job to transmit pain signals to the brain. Along this idea, we have simple cryoanalgesia techniques that we use in sports medicine, including cold sprays, that make the pain go away in a localized spot for a temporary amount of time.

However, when we’re talking about it as it relates to surgical pain relief, cryoanalgesia involves using a very small probe that delivers a freezing temperature to a targeted nerve or nerve bundle, causing it to become numb. This is achieved by using a very controlled delivery of gas through the probe, and the sudden expansion of gas makes its temperature go significantly low. This results in a controlled destruction of the inner functional part of the nerve, which then takes a while to grow back using its outer layers. So, by damaging the nerve locally in one particular space, the nerve stops sending signals back to the brain so that we don’t have pain associated with that section of the body for a reversible but relatively longer amount of time.

How is that different than a nerve block?
The big difference is that this involves a controlled destruction of the nerve fibers. This is not a pharmacological technique like a nerve block. Instead, the nerve is damaged and then grows back at a rate of roughly 1-2 mm per day, so the pain relief is much more long-lasting — usually a few weeks to a month is what we expect. The distinct advantage by comparison is the long duration of pain relief with cryoanalgesia versus a few hours or days of relief with a nerve block.

Is that cryoanalgesia’s big benefit—long pain relief? Are there any others?
Yes, cryoanalgesia offers several benefits for patients undergoing surgery or other medical procedures. Right now, the surgical, perioperative and anesthesia communities are looking for options where we can have control over long-term nerve blockades, such that it influences recovery for days. By numbing specific nerves using extreme cold temperatures, cryoanalgesia can block pain signals and provide long-lasting relief without the need for traditional forms of anesthesia or opioids. This can lead to a faster recovery time and fewer side effects for patients, as well as reduced healthcare costs associated with longer hospital stays and more complex pain management regimens. In cases where chronic post-op pain tends to be a major challenge, cryoanalgesia can be an effective option that also minimizes reliance on opioids.

Another benefit is its minimally invasive nature. Unlike other forms of anesthesia that require catheters to be inserted into the body, cryoanalgesia uses a small probe to deliver the freezing temperature to the targeted nerve. Nerve catheters, although conceptually nice, require dedicated personnel to troubleshoot and have potential for infection. Application of cryoanalgesia may not require deep sedation or general anesthesia and patients can often resume their normal activities within a short period of time.

Those sound advantageous, especially in light of the opioid epidemic. Are there reasons why cryo isn’t being used more frequently?
There are some challenges and potential drawbacks to consider. One potential issue is the risk of nerve damage, which can occur if the freezing temperature is applied for too long or if the probe is not placed correctly. This can result in a loss of sensation or motor function in the affected area, which may require additional medical attention or even surgery to correct. It’s important for medical professionals to have specialized training and experience in using cryoanalgesia to minimize these risks.

Additionally, in some circumstances, the type of nerve associated with the area being operated on may make it hard to use cryoanalgesia. For example, in a shoulder procedure, we may need to use cryoanalgesia on a motor nerve to provide effective relief which would then cause the patient to lose some movement in their shoulder until they are completely healed. Instead, we need to rely on sensory nerves as much as possible for this technique.

There’s also limited research available on its long-term effects. While the technique has been shown to be effective in providing short-term pain relief for outpatient procedures, there is still a need for more studies to evaluate its safety and efficacy over longer periods of time.

Which procedures are using cryoanalgesia most often right now?
It’s being used in many surgeries where sensory nerves can be targeted. For example, it’s well suited for operations taking place in the patient’s chest because the surgeon can clearly see the nerve and use cryoanalgesia directly within the chest to provide relief. We’re also seeing it for phantom limb pain, sciatica, and even some shoulder and knee surgeries. The biggest change we’ve seen is that more providers are targeting those sensory nerves, which opens it up to more procedures. For example, though there are motor nerves in the knee, thanks to advances in ultrasound technology, we can target smaller sensory nerves in that same area and provide better relief without impacting the knee’s motor function.

Is that why we’re seeing more growth in the cryoanalgesia field?
The improvement in technology is behind much of the growth. There are a lot of advantages to cryoanalgesia that were maybe overlooked due to limitations of existing techniques. But at the same time, we realized we have a need for the long-term pain relief effect. Because the technology is getting better, and more companies are investing in these technologies, that’s what’s driving this. As someone who is always researching technologies that would help us improve patient outcomes and decrease reliance on opioids, I’m excited to see how the field continues to grow. OSM