Assessing the effectiveness and cost effectiveness of subcutaneous nerve stimulation in patients with predominant back pain due to failed back surgery syndrome (SubQStim study): study protocol for a multicenter randomized controlled trial

Abstract

BackgroundChronic radicular pain can be effectively treated with spinal cord stimulation, but this therapy is not always sufficient for chronic back pain. Subcutaneous nerve stimulation (SQS) refers to the placement of percutaneous leads in the subcutaneous tissue within the area of pain. Case series data show that failed back surgery syndrome (FBSS) patients experience clinically important levels of pain relief following SQS and may also reduce their levels of analgesic therapy and experience functional well-being. However, to date, there is no randomized controlled trial evidence to support the use of SQS in FBSS.Methods/DesignThe SubQStim study is a multicenter randomized controlled trial comparing SQS plus optimized medical management (‘SQS arm’) versus optimized medical management alone (‘OMM arm’) in patients with predominant back pain due to FBSS. Up to 400 patients will be recruited from approximately 33 centers in Europe and Australia and will be randomized 1:1 to the SQS or OMM arms. After 9 months, patients who fail to reach the primary outcome will be allowed to switch treatments. Patients will be evaluated at baseline (prior to randomization) and at 1, 3, 6, 9, 12, 18, 24, and 36 months after randomization. The primary outcome is the proportion of patients at 9 months with a ≥50% reduction in back pain intensity compared to baseline. The secondary outcomes are: back and leg pain intensity score, functional disability, health-related quality of life, patient satisfaction, patient global impression of change, healthcare resource utilization/costs, cost-effectiveness analysis and adverse events. Outcomes arms will be compared between SQS and OMM arms at all evaluation points up to and including 9 months. After the 9-month assessment visit, the main analytic focus will be to compare within patient changes in outcomes relative to baseline.DiscussionThe SubQStim trial began patient recruitment in November 2012. Recruitment is expected to close in late 2014.Trial registrationClinicalTrials.gov NCT01711619

The Appropriate Use of Neurostimulation of the Spinal Cord and Peripheral Nervous System for the Treatment of Chronic Pain and Ischemic Diseases: The Neuromodulation Appropriateness Consensus Committee

“…However, before concluding that this technique of lead placement is equal to, better than, or worse than conventional placements of SCS leads via an epidural needle, an RCT should be performed comparing the two techniques. PfNS is the subject of a European trial, comparing it with usual care in FBSS with axial back pain . The study has started recruiting in Europe; a similar study is to start in the USA.…”

Effects of Tonic Spinal Cord Stimulation on Sensory Perception in Chronic Pain Patients: A Systematic Review

“…Several targets other than the spinal cord are used for neuromodulation therapies, including peripheral nerves and the brain. In peripheral nerve field stimulation, the leads are located in the layer of the skin called the hypodermis to reach small nerve fibers that are difficult to target with more central nerve fiber stimulation . In peripheral nerve stimulation, leads are implanted next to peripheral nerves, such as the greater occipital nerve and lesser occipital nerve for severe chronic migraine .…”

A Randomized Controlled Trial of Subcutaneous Nerve Stimulation for Back Pain Due to Failed Back Surgery Syndrome: The SubQStim Study

“…The study was conducted in 25 sites across Europe, Israel, and Australia, and in accordance with ISO 14155 and under the approval of each sites' ethics committee. The study protocol was published elsewhere .…”

“…In its entirety, the study was conceived to include two periods, first a nine‐month two parallel arm randomization phase and an open‐label long‐term follow‐up period to 36 months as described previously . After nine months, qualifying subjects could cross‐over arms if they wished and returned for visits at 12, 18, 24, 30, and 36 months.…”

“…The approach to sample size calculation has been previously described . The original plan was to enroll up to 400 subjects to obtain 314 evaluable subjects (taking into account screen or baseline failures and post‐randomization attrition).…”