cryoneurolysis

Cryoneurolysis is a medical procedure that uses extreme cold to injure a peripheral nerve with the aim of reducing pain signaling. It is a form of neurolysis designed to provide longer-lasting relief than local anesthetic blocks while attempting to preserve surrounding tissues and structure. The effect is usually limited to the targeted nerve, and recovery depends on the nerve's ability to regenerate.

Cryoneurolysis relies on freezing temperatures to disrupt axons while often maintaining the surrounding connective tissue sheath. Ice crystal formation and vascular injury cause axonotmesis, leading to temporary loss of sensation and nerve conduction distal to the lesion. Because the connective tissue layers are preserved, some nerves may regenerate over weeks to months, and sensory or motor function may recover progressively.

The procedure is performed by percutaneous insertion of a cryoprobe near the target nerve under ultrasound or fluoroscopic guidance, typically with local anesthesia and sometimes light sedation. The cryoprobe cools to temperatures that create a defined freeze-zone in the nerve, with careful monitoring to limit skin or non-target injury. Repeated freeze-thaw cycles may be used depending on the clinical goal.

Indications include chronic peripheral neuropathic or nociceptive pain that is focal and amenable to a nerve-targeted approach, such as certain neuralgias or nerve entrapments. It is generally considered after noninvasive therapies have failed and may be used to manage pain or reduce spasticity in selected patients. Onset of relief can be immediate and may last weeks to months, with longer durations reported in some cases.

Risks are usually modest but can include transient or persistent numbness, weakness, neuropathic pain, infection, or unintended nerve injury. Skin frostbite or cold-induced injuries are possible but minimized with careful technique. Cryoneurolysis differs from thermal ablation in its tissue-preserving intent and potential for nerve regeneration.