Radiofrequency Neurotomy for Pain Management

Living with chronic pain can be debilitating and life-altering. For individuals suffering from pain originating in joints, such as facet joint pain, sacroiliac joint pain, or even certain types of headaches, relief can be hard to come by. Traditional treatments may not always provide the desired results, leaving patients in search of alternative solutions. This is where radiofrequency neurotomy (RFN) comes into play. RFN, also known as radiofrequency ablation (RFA), is a cutting-edge interventional procedure that has revolutionised the field of pain management. In this article, we will delve into the world of RFN, exploring its history, applications, and the evidence behind its efficacy.

What is Radiofrequency Neurotomy?

Radiofrequency neurotomy is a medical procedure designed to alleviate pain arising from specific joints and nerves in the body. It is particularly effective for conditions like facet joint pain, sacroiliac joint pain, and certain types of headaches. The procedure involves the use of alternating electrical current, which is delivered through an electrode enclosed within a needle. This electrical current generates intense heat (above 60°C) at the needle’s tip, effectively damaging the targeted nerve to provide pain relief.

RFN is not a one-size-fits-all solution. Before undergoing this procedure, patients must first establish that the pain originates from the affected joints and branch nerves. This is typically done through a diagnostic form of spinal injection, which confirms the source of pain and ensures that other treatment methods have been ineffective.

The beauty of RFN lies in its ability to offer long-lasting pain relief, often spanning several months. Nevertheless, it’s important to note that nerves have the capacity to regenerate, which means that pain may eventually return after the nerve regrows. RFN procedures are performed under X-ray guidance in a day surgery setting, ensuring precision and safety.

Radiofrequency Neurotomy (RFN)

Before diving into the details of the RFN procedure, there are certain preparations patients should be aware of:

Medication Adjustments: All blood-thinning products, except for aspirin, must be discontinued before the procedure. Patients will receive specific instructions on when to stop taking these medications when scheduling their admission date. Regular medications can be taken on the morning of the procedure, with a sip of water.
Insulin-Dependent Diabetics: Patients with insulin-dependent diabetes will be scheduled as the first case of the day and should bring their insulin with them. It will be administered following the procedure.
Fasting: Patients should refrain from eating, drinking, smoking, or chewing anything prior to the procedure.
Transportation: It is crucial to arrange for someone to drive you home after the RFN procedure since you will be unable to drive for 24 hours post-procedure.

The RFN procedure

Admission and Preparation: Upon arrival at day surgery, a nurse will admit you and provide a gown to change into. An anaesthetist will place a plastic needle (cannula) into a vein in your hand.

Positioning: You will be positioned on the procedure table, usually lying on your abdomen with a pillow under your hips and abdomen. An earthing pad will be applied to the back of your leg. For cervical medial branch RFN, you will be positioned on your side with the affected side facing upward.

Sedation: The anaesthetist will administer sedation via your vein to keep you comfortable during the procedure.

X-ray Guidance: An X-ray machine will be used to precisely locate the area where the doctor will insert the needle for the RFN procedure. The entire procedure typically takes 30 to 40 minutes to complete.

Sensory Stimulation: To ensure accurate placement, sensory (and sometimes motor) stimulation will be performed. You will be asked to notify the medical staff as soon as you feel a tingling sensation (sensory stimulation). This step is crucial for pinpointing the correct location.

Local Anaesthetic and RFN: After successful sensory stimulation, a local anesthetic will be applied, followed by the commencement of radiofrequency neurotomy. The local anaesthetic ensures that you do not experience pain during the procedure. Each radiofrequency lesion takes about 90 seconds, with at least two lesions typically performed at each level.

Recovery: After the procedure, you will be placed on a trolley and taken to the recovery area, where you will remain for approximately one hour.

Discharge: After consuming food and drink, you will be discharged with a caregiver.

Post-RFN Recovery

Following the RFN procedure, it’s advisable to engage in gentle activity and rest during the first 24 hours. Cold packs should be applied to the injection sites during this time, and heat packs can be used if preferred after 24 hours. Some discomfort at the RFN site may persist for up to five days.

Within 24 to 48 hours post-procedure, a nurse will contact you to discuss the outcome of the procedure and schedule a follow-up appointment.

History of Radiofrequency Neurotomy

The history of radiofrequency neurotomy dates back to the early 1930s when Kirschner conducted the first known RFN procedure to treat trigeminal neuralgia. His groundbreaking work showcased how continuous radiofrequency (CRF) current could create a thermal lesion in a neural pathway, interrupting nociception. Over the decades, this technology evolved, with Shealy and Bogduk refining percutaneous medial branch RF neurotomy techniques in the 1950s. Initially, RFN was limited to treating cervical and lumbar facet diseases due to technological constraints. However, today’s RFN procedures have expanded to address various pain pathologies, thanks to innovations in technology and technique.

Pulsed radiofrequency (PRF) technology emerged in 1995, aiming to reduce the risk of motor deficits by using magnetic field exposure instead of thermal coagulation. PRF has shown promise in treating a range of pain conditions, offering an alternative to traditional CRF procedures.

Cooled radiofrequency (CRFN) thermal neurotomy, despite its name, allows for larger thermal lesions than traditional RFN. It has gained traction since its inception in cardiac electrophysiology and tumour ablation. CRFN is now being explored for chronic knee, hip, and back pain, with promising results.

The Evolution of Radiofrequency Neurotomy

Over time, RFN has evolved and expanded its applications, making it a vital tool in pain management. The American Society of Pain and Neuroscience (ASPN) recognised the need for evidence-based guidance due to RFN’s novel applications and different radiofrequency modalities.

To address this need, a multidisciplinary workgroup of pain medicine specialists was formed. This group aimed to provide best practice guidelines and evidence-based recommendations for various RFN applications, including the cervical, thoracic, and lumbar spine, posterior sacroiliac joint pain, hip and knee joints, and occipital neuralgia.

The RFN Evidence-Based Guidelines

The workgroup conducted an extensive literature search, encompassing randomised controlled trials and prospective and retrospective observational studies. They excluded conference proceedings, expert opinions, and unpublished data, focusing on high-quality research that could inform their recommendations.

Here’s a summary of the evidence and recommendations for some anatomical targets of RFN:

1. Cervical Medial Branch Radiofrequency Neurotomy:

– Used for chronic neck pain and cervicogenic headache.
– Diagnostic cervical medial branch or facet blocks are typically employed.
– The evidence suggests moderate support for the efficacy of cervical medial branch RFN.

2. Thoracic Medial Branch Radiofrequency Neurotomy:
– Used to treat chronic thoracic/mid-back pain.
– Diagnosis often relies on diagnostic injections.
– The literature on thoracic RFN is relatively scarce, with low-level evidence.

3. Lumbar Medial Branch Radiofrequency Neurotomy:
– A common procedure for treating low back pain due to lumbar facet joint disease.
– Diagnostic blocks, including medial branch blocks, are commonly used.
– Lumbar RFN has strong evidence supporting its efficacy.

4. Lateral Sacral Branch Radiofrequency Neurotomy:
– Used to address sacroiliac joint dysfunction.
– Diagnostic sacroiliac joint blocks with local anesthetics are commonly employed.
– The evidence for lateral sacral branch RFN varies, with some controlled studies available.

5. Occipital Neuralgia Radiofrequency Neurotomy:
– Primarily used to alleviate symptoms of occipital neuralgia.
– The International Headache Society’s diagnostic criteria are standard practice.
– Diagnostic blockade of the occipital nerves precedes RFN.
– Evidence suggests that pulsed radiofrequency (PRF) may be the preferred technique.

Future Research

The future of RFN in pain management looks promising. Research gaps exist, particularly in the realm of occipital nerve pulsed radiofrequency (PRF). PRF offers the advantage of applying radiofrequency current at lower temperatures, reducing the risk of damage to surrounding tissue and nerves. Future studies will aim to determine the efficacy and safety of PRF and compare it to other RFN options.

Conclusion

Radiofrequency neurotomy, or radiofrequency ablation, has emerged as a powerful tool in the management of chronic pain. This groundbreaking procedure has a rich history of development and evolution, making it a valuable asset in pain management today. RFN’s applications have expanded beyond facet joint pain to include various anatomical targets, providing relief to patients who have not responded well to conservative or surgical treatments. Evidence-based guidelines and recommendations ensure that RFN is used effectively and safely in clinical practice.