SubQStim: A Post-market Study of Subcutaneous Nerve Stimulation in Failed Back Surgery Syndrome (FBSS) Patients

Inclusion Criteria: 1. Provides written Patient Informed Consent/Patient Information Sheet prior to study-related activities being conducted 2. ≥ 18 years of age at time of informed consent 3. Willing and available to attend visits as scheduled and to comply with the study protocol 4. Willing and able to undergo assessments as part of the evaluation for eligibility and endpoints 5. Willing and able to use the external neurostimulator, recharging equipment (if applicable), and patient programmer per the schedule required by the protocol 6. Diagnosed with FBSS (i.e.): * Has had persistent pain for 6 months following most recent anatomically correct, successful surgery AND * There are no further therapeutic surgical options available as assessed by appropriate investigation 7. Back pain is considered intractable and has been adequately treated (failed an appropriate trial of at least 3 different classes of back pain treatments (pharmaceutical and/or non-pharmaceutical)) 8. Is an appropriate implant candidate for the SQS system Exclusion Criteria: 1. Has been or is currently being treated with spinal cord stimulation, subcutaneous nerve stimulation, peripheral nerve stimulation or an implantable intrathecal drug delivery system 2. Evidence of an active disruptive psychiatric disorder that is significant enough to impact the perception of pain, compliance to intervention and/or ability to evaluate treatment outcome, as determined by the investigator 3. Has a pain condition unrelated to FBSS that is severe enough to overshadow the FBSS pain in the opinion of the investigator 4. Spinal instability or anatomic compression that requires further surgery 5. Spinal fusion at more than 3 vertebral levels 6. Currently enrolled in or plans to enroll in any concurrent drug and/or device study that may confound the results of this study 7. Allergic or has shown hypersensitivity to any materials of the device system which come in contact with the body 8. History of coagulation disorder or lupus erythematosus 9. Involved in current litigation regarding back pain