Subcutaneous Peripheral Nerve Stimulation (PNS) as "Hybrid Stimulation" After Failure of Spinal Cord Stimulation (SCS) to Control the Back Pain Component in Failed Back Surgery Syndrome (FBSS) Patients.(CUMPNS Study)

• Age ≥ 18 years and ≤ 80 years.
• History of FBSS after one or more surgical procedures on the spine, treated with SCS,
• Failure of well conducted conservative treatment (drug or non-drug).
• Patients implanted with a single-column or multicolumn SCS lead providing significant relief of the radicular pain component.
• Persistent failure on the low back pain component despite the efficacy of SCS on the radicular pain component.
• Patients with documented residual neuropathic low back pain (DN4, sensorimotor studies, clinical examination, pain characteristics, etc.).
• Patients with significant residual low back pain with mean intensity on Visual Analogue Scale (VAS) ≥ 40 mm) despite Conventional Medical Management (CMM) and SCS (mean measure calculated on daily VAS scores on 5 consecutive days).
• Positive response to Transcutaneous Electrical Nerve Stimulation (TENS) trial on the back pain component.
• Patients understanding and accepting the study constraints.
• Patients covered by French national health insurance.
• Patients have signed the Informed Consent Form after being provided with clear and honest information about the study.
• Absence of active psychosis or serious psychotic history requiring hospitalisation.
• Absence of active cancer.

Exclusion Criteria:

• Age \< 18 years and > 80 years.
• Back pain amenable to further aetiological biomechanical surgery (discogenic pain, spinal instability, spinal deformity, etc.).
• Surgical, psychiatric or anaesthetic contraindication to PNS lead implantation.
• Negative response to TENS trial.
• Absence of signature of the informed consent form.
• Patients not covered by French national health insurance.
• Subjects requiring closer protection, i.e. minors, pregnant women, nursing mothers, subjects deprived of their freedom by a court or administrative decision, subjects admitted to a health or social welfare establishment, major subjects under legal protection, and finally patients member of a high-risk population.
• Women of childbearing age not using effective contraception.