Cryolesion is an alternative to thermolesion – instead of high temperature, it uses extreme cold for precise, controlled and reversible blockade of nerve conduction. It provides months of pain relief, and after regeneration of nerve fibres the full anatomical function of the nerve is preserved – making cryolesion one of the safest neurodestructive techniques.

Mechanism of Action – How Does Cold ‘Switch Off’ the Nerve?

During cryolesion, the tip of a special probe cools through gas expansion (CO₂ – to −78°C or N₂O – to −130°C). A controlled freezing zone (‘ice ball’) 5–10 mm in diameter forms around the tip. Within this zone a series of processes occur:

  • Intra- and extracellular ice crystals form, damaging the microtubules and cell membranes of the axon
  • The nutrient blood vessels of the nerve (vasa nervorum) are damaged, leading to endoneurial oedema
  • Controlled axon damage known as WALLERIAN DEGENERATION occurs – the nerve fibre degenerates distal to the freezing point
  • KEY DIFFERENCE from thermolesion: the endoneurium, perineurium and epineurium (connective tissue sheaths of the nerve) remain INTACT
  • Thanks to the preserved sheath structure, the axon regenerates along its original path at a rate of 1–2 mm/day without an intense post-denervation inflammatory response
  • After full regeneration (6–12 months), the nerve recovers full function – no risk of neuroma formation, no deafferentation pain, no post-procedural neuralgia

Wallerian degeneration in Sunderland’s nerve injury classification corresponds to Grade II (axonotmesis) – this is a deliberate and controlled, reversible injury. This is the fundamental advantage of cryolesion over thermolesion (which causes Grade III/IV damage – irreversible) and over chemical alcohol neurolysis (Grade V damage).

Clinical Indications

Peripheral joints

  • Knee joint degenerative disease – cryolesion of genicular nerves (alternative to Cooled RF)
  • Advanced coxarthrosis – cryolesion of obturator and femoral nerve branches
  • Shoulder pain – cryolesion of the suprascapular nerve
  • Dedicated special probes (e.g. Knee, SIJ) increasing lesion volume

Spine

  • Facet joint pain syndrome – cryolesion of medial branches under X-ray (alternative to RFA)
  • Sacroiliac joint pain (sacroiliitis) – cryolesion of dorsal branches S1–S3

Peripheral nerves and special indications

  • Morton’s neuroma – cryolesion is the safest option (regeneration vs permanent surgical damage)
  • Greater trochanter pain syndrome and ischial tuberosity pain
  • Cryolesion of enthesopathies (chronic inflammatory conditions at tendon insertions)
  • Genitofemoral neuralgia (spermatic cord) – after inguinal hernias
  • Intercostal pain (post-thoracotomy, post-mastectomy) – cryolesion of intercostal nerves
  • Occipital neuralgia (in the absence of response to PRF)
  • Phantom and post-amputation pain
  • Endometriosis and pelvic neuralgia

Procedure Sequence

  • Qualifying consultation and diagnostic block (confirms the nerve in question is the pain source).
  • Patient positioning, local skin anaesthesia.
  • Under fluoroscopic X-ray or ultrasound guidance, introduction of the cryolesion probe (typically 14G–16G diameter) near the nerve.
  • Neural stimulation to confirm localisation – sensory stimulation (50 Hz) produces the patient’s familiar pain; motor stimulation (2 Hz) confirms absence of muscle contraction.
  • Freezing cycle: typically 2–3 cycles of 2–3 minutes of freezing with 30-second thawing intervals. During this time the ‘ice ball’ visible on ultrasound forms around the probe tip.
  • One-point procedure takes 8–12 minutes; the entire session depending on the number of points – 30–90 minutes.
    20. Post-procedure observation for 30 minutes; discharge with a third-party driver.

Preparation

  • Positive diagnostic block (>50% pain reduction)
  • Current imaging studies
  • Discontinuation of anticoagulants per protocol
  • No need to fast
  • Return transport
  • Contraindications: cryoglobulinaemia, active phase Raynaud’s disease, pregnancy, active skin infection

Effects

  • First relief: immediately after the procedure (effect of cold and local anaesthesia) or within 1–2 weeks (after full development of Wallerian degeneration)
  • Full effect: 4–6 weeks
  • Duration of effect: typically 6–12 months (until axon regeneration)
  • In some patients, pain does not return at full intensity after regeneration – a phenomenon of descending pathway modulation and reversal of central sensitisation
  • The procedure can be safely repeated multiple times without cumulative tissue damage

Possible Side Effects

  • Transient hyperaesthesia (increased sensitivity) or hypoaesthesia in the nerve area – a few weeks
  • Minor haematoma/swelling at the puncture site
  • Very rarely – damage to adjacent tissues (skin with superficial nerves – we apply warm air skin protection during the procedure)
  • Occasionally – earlier than expected pain return (with incomplete cryogenesis)
  • NO risk of deafferentation neuralgia or painful neuroma (unlike surgical neurotomy)

FAQ

Is cryolesion more effective than RFA thermolesion?

Both techniques have comparable efficacy in many indications (comparative studies in gonarthrosis). Cryolesion is generally preferred for superficial peripheral nerves, neuromas, mixed nerves and where full reversibility of effect is desired. RFA – for deep purely sensory nerves (spinal medial branches).

Is the cryolesion effect permanent?

No – the effect is intentionally reversible (6–12 months), as the nerve regenerates functionally. This is an advantage, not a drawback: the procedure can be repeated, and in some patients with each procedure the pain becomes progressively weaker (central modulation).

Is cryolesion painful?

The procedure itself is virtually painless thanks to local anaesthesia and the intrinsic analgesic properties of cold. After the procedure, patients often experience immediate relief.