Comprehensive Evidence-Based Guidelines for Implantable Peripheral Nerve Stimulation (PNS) in the Management of...

Peripheral nerve stimulation (PNS) has been used for over 50 years to treat chronic pain by delivering electrical pulses through small electrodes placed near targeted peripheral nerves those outside the brain and spinal cord. Early PNS systems often required invasive neurosurgical procedures. However, since 2015, the Food and Drug Administration (FDA) approved percutaneously implanted PNS leads and neurostimulators  offering a much less invasive, non-opioid option for managing recalcitrant chronic pain. The following FDA-cleared PNS systems are commercially available in the United States for the management of chronic, intractable pain:•    Freedom® Peripheral Nerve Stimulator (PNS) System (Curonix LLC, 2017) •    StimRouter® Neuromodulation System (Bioness, now Bioventus, 2015)•    SPRINT® PNS System (SPR® Therapeutics, Inc., 2016) •    Nalu™ Neurostimulation System (Nalu Medical Inc., 2019)•    ReActiv8® Implantable Neurostimulation System (Mainstay Medical Limited, 2020) The American Society of Interventional Pain Physicians (ASIPP) has published evidence-based consensus guidelines for the application of PNS systems in managing chronic pain.

The guidelines aim to provide evidence-based recommendations for the utilization of peripheral nerve stimulation (PNS) in the management of moderate to severe chronic pain. These guidelines exclude field stimulation, or sacral nerve stimulation.

A multidisciplinary panel of experts in various medical and pharmaceutical fields, convened by ASIPP, reviewed the evidence, considered patient perspectives, and formulated recommendations for implantable peripheral nerve stimulation in chronic pain management. The methodology included developing key questions with evidence-based statements and recommendations. The grading of evidence and recommendations followed a modified approach described by ASIPP, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) method, and the Agency for Healthcare Research and Quality (AHRQ) strength of recommendations methods. The evidence review includes existing guidelines, systematic reviews, comprehensive reviews, randomized controlled trials (RCTs), and observational studies on the effectiveness and safety of implantable peripheral nerve stimulation in managing chronic pain. The quality of published studies was assessed using appropriate instruments for systematic reviews, RCTs, and observational studies.In the development of consensus statements and guidelines, we used a modified Delphi technique, which has been described to minimize bias related to group interactions. Panelists without a primary conflict of interest voted to approve specific guideline statements. Each panelist could suggest edits to the guideline statement wording and could suggest additional qualifying remarks or comments as to the implementation of the guideline in clinical practice to achieve consensus and for inclusion in the final guidelines, each guideline statement required at least 80% agreement among eligible panel members without primary conflict of interest.

A total of 31 authors participated in the development of these guidelines. Of these, 23 participated in the voting process. A total of 8 recommendations were developed. Overall, 100% acceptance was obtained for 8 of 8 items. Thus, with appropriate literature review, consensus-based statements were developed for implantable peripheral nerve stimulation in chronic pain management. In preparation of these guidelines, evidence synthesis included 7 systematic reviews, 8 RCTs, and 9 observational studies covering all PNS treatments. The evidence was developed using GRADE criteria or certainty of evidence, and qualitative synthesis based on the best available evidence. The evidence level and recommendations are as follows: For implantable peripheral nerve stimulation systems following a trial or selective lumbar medial branch stimulation without a trial, the evidence is Level III or fair with moderate certainty.  Evidence Level: Fair; Strength of Recommendation: ModerateFor temporary peripheral nerve stimulation for 60 days, the evidence is Level III or fair, with moderate certainty.

Fair; Strength of Recommendation: ModerateBased on the available evidence, it is our recommendation to expand the existing PNS related local coverage determination (LCD) to include craniofacial pain, phantom limb pain, and nociceptive pain in the lower back as present evidence shows Level III or fair with moderate certainty.

The primary limitation of these guidelines is the paucity of the available literature.

These evidence-based guidelines support the use of implantable peripheral nerve stimulation leads and neurostimulators in patients with moderate to severe chronic pain refractory to two or more conservative treatments. These guidelines aim to optimize patient outcomes and promote health equity through the integration of PNS technology in clinical practice.