Intradiscal Modulation

The term "internal disc disruption" (IDDS) is used to identify the syndrome of low back pain with or without leg pain in the setting of degenerative disc disease (DDD) without nerve root compression (sciatica). Treatment has traditionally been limited to either conservative medical management or open surgery. Surgical treatment including lumbar fusion or disc replacement surgery has yielded mixed results. Given the prevalence (very common) of this problem and the limited treatment options, the development of alternative treatment methods is the logical advancement of care. This has lead to the evolution of minimally invasive, fluoroscopically-guided, intradiscal procedures as another step in the treatment algorithm for chronic discogenic pain. These intradiscal methods include:

• Intradiscal electrothermal therapy (IDET)
• Biacuplasty (Transdiscal)
• Radiofrequency posterior ablation (RFA)
• Percutaneous laser disc decompression (PLDD)
• Nucleoplasty (coblation).

Despite early promising results, no single approach has proven itself to be the definitive minimally invasive solution to internal disc disruption. The current leading technologies are IDET and biacuplasty. Each offers a modest rate of success for relieving severe low back pain associated with IDDS while avoiding the risks of major surgery. However, it should be noted that some patients do not experience any pain relief, and the long-term results of these procedures are not yet known.

IDET

The IDET procedure takes about one hour to complete. A hollow needle is inserted into the damaged disc with the guidance of an x-ray machine. A special wire, called an electrothermal catheter, is then threaded down through the needle and into the disc. The wire is heated through electrical current over the course of about 16 minutes. The high heat destroys the small nerve fibers that have grown into the cracks of the disc and that transmit pain. The heat also partially melts the annulus (the outer wall of the disc), which triggers the body to generate new proteins to strengthen the disc.

After the procedure, there is a short observational period prior to release. During recovery, the patient must rest for a few days and may need to wear a back support for several weeks. Pain relief is sometimes seen within a few days of the procedure, or may take several weeks to several months to be noticed. During this time, medications can be prescribed to reduce pain. Physical therapy is necessary to help reduce pain and increase flexibility and spinal strength. In addition, it will be several months before rigorous activity, heavy lifting or twisting can be resumed. In time, however, the pain is expected to decrease and the need for medications can be reduced or eliminated. Activity levels can then increase as well as a return to an active life.

Intradiscal Biacuplasty

Fig 1. Illustration demonstrating a band of radiofrequency current between 2 Transdiscal probes.
Fig. 2 Intra-operative x-ray of the final placement of two Transdiscal probes.

Intradiscal Biacuplasty utilizes a bipolar system that includes two cooled, radiofrequency electrodes placed on the posterolateral sides of the outer ring of the disc (annulus fibrosus). Cooled radiofrequency may increase the lesion size and facilitate ablation (neurotomy of the nerve fibres in the back of the disc) compared to standard RF electrodes.

Biacuplasty is still in its early stages of clinical research. Early results are very encouraging. This procedure offers the advantage of being a much simpler operative technique than its predecessor, IDET. At the same time, the early studies have shown positive results that may be superior to those of IDET.

Intradiscal Modulation in BC

Although both IDET and biacuplasty have been approved by Health Canada, neither is currently being performed in BC. The Royal College of Physicians and Surgeons of British Columbia is well aware of the potential benefits (demonstrated in early trials) of these procedures for patients with discogenic low back pain. However, the College has recommended waiting until further supportive studies have been performed, before offering such treatment to its residents. The Royal College of Physicians and Surgeons of BC considers the safety and well being of both its patients and physicians its top priority.

Currently, randomized controlled trials (high quality studies) are being performed in the U.S. and Canada. In the meantime, Dr. Helper is performing the necessary diagnostic work-ups for patients with discogenic low back pain. If patients are found to meet the strict qualification criteria for Intradiscal Modulation, they will have the option of being referred A) to a qualified practitioner who regularly performs the procedure, or B) to one of the academic study centres to participate in the ongoing clinical trial.