David Prologo, MD, presented on cryoneurolysis at the Symposium on Clinical Interventional Oncology (CIO) in Miami, Florida. Dr. Prologo is an interventional radiologist from Emory University in Atlanta, Georgia, and his presentation identified opportunities for intervening with cryoneurolysis, explained benefits for patients, and compared nerve blocks and cryoneurolysis.
What is cryoneurolysis, and which patients can benefit from treatment?
Cryoneurolysis uses the skillset of the interventional radiologist to target nerves with devices that decrease temperature. This is an extraordinarily valuable intervention in the setting of metastatic cancer. Lowering the temperature allows us to shut off the pain signal and can help patients who have intractable pain related to a tumor. We are able to decrease pain by using computed tomography guidance, placing the probe, and freezing the nerve. Pain relief occurs whether the tumor is pressing on a nerve, is distal to the nerve, or is anywhere near the nerve.
Intervening with cryoneurolysis gives us opportunities to help patients who do not have other options. Often, patients with pain may go to radiation therapy for multiple treatments, and pain relief may take weeks to occur. The cryoneurolysis procedure is about 45 minutes, and recovery is quick. Patients can be treated and pain can be relieved in one day. Cryoneurolysis is a safe, percutaneous option. We are excited and blessed to be able to help these folks.
Can you tell us about nerve blocks and how they compare with cryoneurolysis?
A nerve block is usually an injection of a steroid or injection of a short-acting anesthetic. Nerve blocks are most helpful for people with an orthopedic issue such as tennis elbow or tarsel tunnel syndrome. Nerve blocks may also be useful for headaches or occipital neuralgia. However, with the intense pain from metastatic cancer or from a tumor pressing on a nerve, a nerve block is like throwing a pebble into the ocean. Cryoneurolysis is more suitable for the pain experienced by cancer patients. Using cryoneurolysis, we guide a needle to the nerve just as we would with a nerve block, but we decrease the temperature to -40C, instead of injecting medications that often have little effect in the setting of cancer. Cryoneurolysis can stop the signal in the nerve altogether, which offers a much more dramatic and permanent response than that seen with nerve blocks. Overall, nerve blocks are great in certain cases, but in the setting of pain from cancer, we have a much bigger gun in cryoneurolysis.
How long does pain relief last from cryoneurolysis?
Relief can last for six months to a year, and we can repeat the procedure again if it is needed after that time period.
Are there any complications or downsides to cryoneurolysis?
There is always a small risk of bleeding and infection that goes along with any procedure, but the benefits typically far outweigh the risks.
How widely is cryoneurolysis used among your colleagues?
As a field, we are now gaining a deeper understanding of the mechanism of pain relief, and this understanding is allowing us to do new procedures such as cryoneurolysis. Part of our purpose in presenting at CIO is to let other interventional radiologists know that this new option is available.
In fact, there is already an FDA approval for cryoneurolysis for the management of pain. It is an existing indication for the devices, so cryoneurolysis is not off-label.
From a technical standpoint, what should interventional radiologists know about performing cryoneurolysis?
Most interventional radiologists have the ability to perform cryoneurolysis and only need to be educated regarding the indications. It is important to keep in mind that existing cryoablation probes were designed to kill cancer, but cryoneurolysis uses these probes to attenuate nerves. In the long run, there are some intricacies involved that will require either refinement of an existing device or development of a new device in order to precisely perform the procedure in a widespread manner. Using the current probes, operators need to know that protocols for using the probe for cryoablation versus for cryoneurolysis are different in terms of freeze times, the nature of the freeze, etc. Potential operators must be educated in these differences before performing cryoneurolysis.
With that goal of education in mind, the Society of Interventional Radiology is developing education modules, publishing papers, and writing books. We are also available for consultation and to travel and teach.
Does cryoneurolysis interfere with any other treatment patients may be receiving?
No, cryoneurolysis does not interfere with other treatments patients may undergo. Patients do not have to interrupt their chemotherapy or any other regimen to receive cryoneurolysis, and patients do not need to be at the end of their life in order to be treated with cryoneurolysis. Some patients have isolated painful metastatic deposits in their bones, and those patients are great candidates for the procedure.
For patients who are in need of palliative care, cryoneurolysis is an excellent option. Pain is often the factor that keeps patients from leading the full life that they could live. Whether their remaining lifespan is 1 year or 10 years, patients want to spend that time with their loved ones and do not want to experience the side effects of opioids. Cryoneurolysis allows them to have pain relief while still remaining lucid. The government is calling on physicians and researchers to develop procedural alternatives to opioids. And that's exactly what cryoneurolysis offers, a procedural alternative to opioids.
Cryoneurolysis also accelerates patients’ discharge from the hospital. Patients will often be admitted with intractable pain and will be hospitalized for weeks while undergoing radiation and receiving narcotics. Instead, we can perform cryoneurolysis on an outpatient basis and they can leave the hospital the next day.
What are the main takeaways from your presentation?
The most important takeaway is that interventional radiologists have a refined and available procedural alternative to opioids. Another important point is that reimbursement mechanisms are evolving. Historically, reimbursement has been a real-world issue that has been a barrier to performing the procedure. We are now working to get that fixed. It has been a multi-year effort with the American Medical Association to have codes assigned, and we expect everything to soon be in place.