Using invasive procedures to manage chronic pain

This topic discusses some commonly used invasive procedures for chronic pain management in adults, including percutaneous radiofrequency neurotomy, neuromodulation and epidural blocks (see Commonly used invasive procedures for chronic pain management). It does not include a comprehensive list of invasive procedures used to manage chronic pain, or instructions on how to perform invasive procedures.

Invasive procedures in children younger than 18 years is not within the scope of this topic—seek expert advice.

For the role of intra-articular injections in specific musculoskeletal conditions, see the Rheumatology guidelines.

Invasive procedures are not a first-line management strategy, but for some patients they may be used as part of a multidimensional approach to chronic pain. Seek expert advice if uncertain about the appropriateness of an invasive procedure to avoid recommending a procedure for an indication for which there is inadequate evidence of efficacy; this is particularly important given the potential for serious harms and significant expense of invasive procedures.

Note: Seek expert advice if uncertain about the appropriateness of an invasive procedure.

Ensure the sociopsychobiomedical contributors to the patient’s pain are appropriately managed before considering an invasive procedure because this may negate the need for the procedure. Only consider an invasive procedure for patients who have realistic treatment goals and have used first-line management strategies without significant improvement to their function and quality of life.

Patients should only be referred for an invasive procedure if there is evidence of its efficacy for the particular indication. Seek specialist advice before formally referring a patient for an invasive procedure, including radiologically guided interventions (eg facet joint injections, nerve blocks). Do not refer a patient for an invasive procedure on the basis of radiological findings alone, because radiologically demonstrated lesions are often poorly correlated with symptoms.

Invasive procedures often provide only short-term relief. During this time, patients should focus on improving self-management, function and quality of life. Expected outcomes from the invasive procedure (eg improved function, reduced analgesic use) should align with the patient’s goals, and be measured at regular intervals (appropriate to the procedure).

Note: Following an invasive procedure, patients should focus on improving self-management, function and quality of life.

Proceduralists (including general practitioners) performing an invasive procedure must be appropriately trained, and their equipment and facilities should meet the requirements outlined in the Faculty of Pain Medicine Procedures in Pain Medicine Clinical Care Standard .

Figure 1. Commonly used invasive procedures for chronic pain management

Percutaneous radiofrequency neurotomy

  • A needle electrode is inserted adjacent to the target nerve (identified by diagnostic block [NB1]) to deliver a localised electrical current that generates small thermal lesions to interrupt nociceptive neural pathways.
  • The underlying pathology of the pain is not affected.
  • If pain relief is achieved, it can persist for several months to years.
  • Limited data suggest the procedure can be repeated when pain returns.
  • Widespread use is not justified—evidence for its efficacy is inconsistent and poor quality.
  • Uses include: trigeminal neuralgia, chronic neck pain, cervicogenic headache due to cervical facet joint pain, low back pain due to lumbar facet joint pain.

Neuromodulation (spinal cord stimulation)

  • An electrode is implanted into the epidural space adjacent to an area of the spinal cord presumed to be transmitting nociceptive signals.
  • The electrode delivers an ongoing, localised electrical current and stimulation of the dorsal column reduces nociceptive signals via multiple mechanisms.
  • Evidence for its efficacy is limited.
  • Use is limited because it is expensive, associated with serious complications and it is not suitable for all patients (contraindications include coagulopathy and therapeutic diathermy).
  • Uses include: complex regional pain syndrome, failed back surgery syndrome, some neuropathic and ischaemic pain syndromes.
  • Problems include: finite battery life, interference with security systems, affected by diathermy, cardiac pacemakers and magnetic resonance imaging.

Epidural block

  • Analgesia is injected into the epidural space to block or modulate neural transmission.
  • A local anaesthetic and corticosteroid are usually co-administered.
  • Evidence for its efficacy is limited.
  • Uses include: chronic spinal stenosis.
  • Do not use for chronic radicular pain because potential harm outweighs potential benefit.
Note: NB1: Local anaesthetic diagnostic blocks (eg medial branch blocks) are used to identify whether a specific nerve is responsive to blockade, and whether that nerve is transmitting nociceptive signals relevant to the pain experience. It may be necessary to perform comparative blocks (eg using short-acting versus long-acting local anaesthetic) because single diagnostic blocks can cause a placebo response.