What is cryoneurolysis?
The term “cryoneurolysis” (Greek: kryos = cold, neuron = nerve, lyein = to release) refers to the targeted interruption of a nerve through the local application of strong cold. The technique has been used for many decades to treat pain. In English, it is sometimes also referred to as "cryosurgery", although it is not an open surgical procedure. Modern cryoneurolysis is a minimally invasive medical procedure in which a special cannula is inserted close to a damaged nerve under ultrasound or X-ray guidance. As soon as the probe has been placed correctly, it is cooled to -78°C using CO2 gas. This rapid cooling causes ice crystals to form in the nerve fibers. This results in a temporary loss of function of the treated nerve without damaging its outer sheath. Ideally, this leads to the desired reduction in pain, but also causes persistent numbness in the area supplied by the nerve.
When is cryoneurolysis helpful?
Careful patient selection is important for successful treatment using cryoneurolysis. Only by blocking the nerve with local anesthetics (e.g. lidocaine) beforehand, we can find out whether cryoneurolysis may be an option for treating the pain at this point. The most accurate possible description of the symptoms (medical history), a targeted physical examination and assessment of the nerve using high-resolution ultrasound can be helpful here. Nerve ultrasound makes it possible to obtain information about the location, type and severity of nerve damage. The subsequent test infiltrations with local anesthetics make it possible to determine the potential benefit of cryoneurolysis at this site.
Cryoneurolysis is performed on an outpatient basis at the IISZ. A treatment takes between 30 and 60 minutes, including preparation and follow-up.
Possible indications
There are several possible indications for treating nerves using cryoneurolysis:
- Electrifying, stabbing facial pain (auricular nerve, trigeminal nerve)
- Radiating neck pain (occipital nerves)
- Post-thoracotomy pain, i.e. chronic chest wall pain after surgery
- Post-herpetic neuralgia, i.e. pain after shingles (intercostal nerves)
- Groin pain after surgery (ilioinguinal nerve, genitofemoral nerve)
- Chronic knee pain, e.g. after surgery (saphenous nerve, genicular nerves)
After a treatment
The extent of the pain reduction achieved by cryoneurolysis and the duration of the effect may vary. Both, individual conditions of a patient as well as the nerve being treated, may affect the result.
Cryoneurolysis can achieve improved pain control over a period of several weeks to 12 months. The goal is to improve quality of life, to enable patients to carry out rehabilitation measures and to take part in usual everyday activities. It should be noted that cryoneurolysis is not usually a permanent treatment. However, if the effect diminishes, it can easily be repeated with comparable results.
Adverse effects and complications
Cryoneurolysis is a comparatively simple treatment that rarely results in complications. If the treatment site is directly under the skin, frost damage to the skin is possible. Otherwise, the same complications are possible as with other injections and infiltrations, but they are all very rare.
