Neuromas are thickenings of tissue around a nerve, which can happen after injuries to the nerve, such as a cut, a crushing injury, nerve compression or an excessive stretch. They are often associated with amputations. Peripheral neuromas affect nerves outside the brain and spinal cord that can carry pain signals between the brain and the rest of the body. This can cause chronic pain.
A common type of neuroma is Morton's neuroma, which affects a nerve that lies between 2 metatarsal bones of the foot. It causes pain in the ball of the foot and sometimes the toes.
Initial treatment for chronic pain caused by a peripheral neuroma may involve physical therapy, medication, or local anaesthetic and corticosteroid injections. NICE's guideline on neuropathic pain in adults describes pharmacological management in non‑specialist settings. Surgical options include decompression and nerve removal.
For Morton's neuroma, conservative management includes measures such as soft pads or insoles to take pressure off the painful area of the foot, wearing shoes with plenty of room in the toes, weight loss and pain medication. If these measures do not work, non-surgical treatments include radiofrequency ablation and injection of corticosteroid or alcohol. If symptoms persist, the affected nerve can be surgically removed.
Image-guided cryoablation of a peripheral neuroma for chronic pain is a percutaneous treatment, which is usually done as an outpatient or day-case procedure under local anaesthesia. Using image guidance (MRI, CT or ultrasound), a needle-like probe is inserted through the skin and near to the neuroma. Inside the probe, gas flows from a high- to low-pressure chamber, creating an extremely cold temperature at the tip. The extreme cold causes reversible destruction of the nerve axon, which disrupts the pain signals. Unlike surgical or heat-mediated ablation, cryoablation does not disrupt the acellular epineurium or perineurium, which may allow eventual nerve regeneration. The time to total regeneration is related to the rate of axonal regrowth and the distance of the lesion from the end organ, so duration of symptomatic relief varies. The procedure can be repeated if necessary.
The main aim of the procedure is to relieve pain but it can also reduce swelling associated with the neuroma.