Medical Policy: 07.01.70
Original Effective Date: December 2015
Reviewed: November 2017
Revised: November 2017
Benefit determinations are based on the applicable contract language in effect at the time the services were rendered. Exclusions, limitations or exceptions may apply. Benefits may vary based on contract, and individual member benefits must be verified. Wellmark determines medical necessity only if the benefit exists and no contract exclusions are applicable. This medical policy may not apply to FEP. Benefits are determined by the Federal Employee Program.
This Medical Policy document describes the status of medical technology at the time the document was developed. Since that time, new technology may have emerged or new medical literature may have been published. This Medical Policy will be reviewed regularly and be updated as scientific and medical literature becomes available.
Peripheral subcutaneous field stimulation (PSFS), also called peripheral nerve field stimulation (PNFS) or target field stimulation, is a form of neuromodulation that is intended to treat chronic neuropathic pain. Applications of PSFS being evaluated are craniofacial stimulation for headache/migraine, craniofacial pain or occipital neuralgia. PSFS is also being investigated for low back pain, neck and shoulder pain, inguinal and pelvic pain, thoracic pain, abdominal pain, fibromyalgia, and post-herpetic neuralgia.
Chronic, non-cancer pain is responsible for a high burden of illness. Common types of chronic pain include lumbar and cervical pain, chronic headaches and abdominal pain. All these conditions can be challenging to treat. Pharmacologic agents are typically the first-line treatment for chronic pain, and several classes of medications are available. These include analgesics (opioid and non-opioid), antidepressants, anticonvulsants, and muscle relaxants. There also are a variety of non-pharmacologic treatments, including physical therapy, exercise, cognitive-behavioral interventions, acupuncture, chiropractic, and therapeutic massage.
Neuromodulation is another form of non-pharmacologic therapy that is usually targeted toward patients with chronic pain that is refractory to other modalities. Some forms of neuromodulation, such as transcutaneous electrical nerve stimulation (TENS) and spinal cord stimulation (SCS), are established methods of chronic pain treatment. Peripheral nerve stimulation, which involves placement of an electrical stimulator on the peripheral nerve, is also used for neuropathic pain originating from peripheral nerves.
PSFS is a modification of peripheral nerve stimulation. In PSFS, leads are placed subcutaneously within the area of maximal pain. The objective is to stimulate the region of affected nerves, cutaneous afferents, or the dermatomal distribution of the nerves, which then converge back on the spinal cord. Combination spinal cord stimulation (SCS) plus PSFS is also being evaluated.
The mechanism of PSFS is unknown. Theories include an increase in endogenous endorphins and other opiate-like substances; modulation of smaller A delta and C nerve fibers by stimulated large diameter A beta fibers; local stimulation of nerve endings in the skin; local anti-inflammatory and membrane depolarizing effect; or a central action via antegrade activation of A beta nerve fibers. Complications of PSFS include lead migration or breakage and infection of the lead or neurostimulator.
Currently, there is no consensus regarding the indications for PSFS. Criteria for a PSFS trial may include a clearly defined, discrete focal area of pain with a neuropathic or combined somatic/neuropathic pain component with characteristics of burning and increased sensitivity, and failure to respond to other conservative treatments including medications, psychological therapies, physical therapies, surgery, and pain management programs.
As with other types of implantable nerve stimulation, implantation of the PSFS is typically a two-step process, the electrode is temporarily implanted, allowing a trial period of stimulation. Once treatment effectiveness is confirmed from the trial stimulation which is defined as at least 50% reduction in pain, the electrodes and neurostimulator are then permanently implanted.
Neuromodulation is another form of non-pharmacologic therapy that is usually targeted toward patients with chronic pain that is refractory to other modalities. Some forms of neuromodulation, such as transcutaneous electrical nerve stimulation (TENS) and spinal cord stimulation (SCS), are established methods of chronic pain treatment. Peripheral subcutaneous field stimulation (PSFS); also called peripheral nerve field stimulation (PNFS) or target field stimulation is being investigated in the treatment of chronic neuropathic pain. Based on review of the peer reviewed medical literature the evidence for the effectiveness of PSFS based on controlled studies is lacking. The literature includes one randomized controlled trial, one nonrandomized comparative study and case series. Further randomized controlled trials are needed comparing PSFS with placebo or alternative treatment modalities to evaluate the efficacy of this treatment for chronic pain as either a stand-alone procedure or adjunct therapy with SCS for chronic neuropathic pain. Therefore, the evidence is insufficient to determine the effects on net health outcomes and peripheral subcutaneous field stimulation (PSFS) is considered investigational for all indications.
Also, no complete PSFS stimulation system has received U.S. Food and Drug Administration (FDA) approval. See Regulatory Status information below.
In 2013 the National Institute for Health and Care Excellence issued guidance on Peripheral Nerve Field Stimulation for Chronic Low Back Pain. The guidance indicated:
“Current evidence on the efficacy of peripheral nerve stimulation (PNFS) for chronic low back pain is limited in both quantity and quality, and duration of follow-up is limited. Evidence on safety is also limited and there is a risk of complications from any implanted device. Therefore, this procedure should only be used with special arrangements for clinical governance, consent and audit for research.”
No devices have been approved by the U.S. Food and Drug Administration (FDA) specifically for peripheral subcutaneous field stimulation (PSFS). PSFS is an off label use of spinal cord stimulation devices that have been approved by the FDA for the treatment of chronic pain.
See also Medical Policy 07.01.61 Spinal Cord Stimulation
Peripheral subcutaneous field stimulation (PSFS) (also called peripheral nerve field stimulation (PNFS) or target field stimulation) to include temporary and permanent placement is considered investigational for all indications including but not limited to the following:
Based on review of the peer reviewed medical literature the evidence for the effectiveness of PSFS based on controlled studies is lacking. Further randomized controlled trials are needed comparing PSFS with placebo or alternateiv treatment modalities to evaluate the efficacy of this treatment for chronic pain as either a stand-alone procedure or adjunct therapy with spinal cord stimulation (SCS). The evidence is insufficient to determine the effects on net health outcomes. Also, no complete PSFS stimulation system has received FDA approval. Therefore, peripheral subcutaneous field stimulation (PSFS) (also called peripheral nerve field stimulation (PNFS) or target field stimulation) is considered investigational for all indications.
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