Permanent Spinal Cord Stimulator Implantation for Failed Back Surgery Syndrome
Yes, permanent implantation of a neurospinal cord stimulator is medically necessary for this patient with failed back surgery syndrome (FBSS) who demonstrated significant benefit (exceeding the 50% pain relief threshold) during a 2-lead trial. 1
Primary Recommendation
The American College of Neurosurgery recommends spinal cord stimulation (SCS) for patients with FBSS and chronic pain when a successful trial demonstrates at least 50% pain relief. 1 This patient's "significant benefit" from the trial meets or exceeds this threshold, establishing medical necessity for permanent implantation. 1
Evidence Supporting Permanent Implantation
Trial Success as Predictor
- A successful trial with substantial pain relief (meeting or exceeding 50% reduction) is a strong positive predictor of long-term success with permanent SCS. 1
- Long-term outcomes demonstrate that 47-59% of FBSS patients achieve ≥50% pain relief at extended follow-up after permanent implantation. 1
- In one series, 75% of patients with permanent implants continued to report at least 50% pain relief at median 34-month follow-up. 2
Clinical Context
- This patient's presentation—chronic low back pain with bilateral radiating leg pain and paresthesias following laminectomy, fusion, and instrumentation—represents classic FBSS, an established indication for SCS. 1, 3
- SCS demonstrates significant advantages over reoperation for persistent pain after back surgery. 1
- The bilateral radicular symptoms with paresthesias indicate neuropathic pain characteristics that respond well to neuromodulation. 4, 5
Required Documentation for Medical Necessity
Before proceeding with permanent implantation, ensure the following criteria are documented:
Functional Disability Assessment
- An Oswestry Disability Index (ODI) score of ≥21% must be documented to establish functional impairment and medical necessity. 1
- The ODI questionnaire should be administered and scored prior to implant to establish baseline functional status. 1
Conservative Treatment Documentation
- Formal in-person physical therapy with a licensed physical therapist for a minimum of 6 weeks within the past year is required. 1
- Documentation must include: dates of service, specific interventions performed, patient response to therapy, and therapist assessment. 1
Psychological Clearance
- Psychological evaluation is necessary to confirm no untreated psychiatric comorbidities or substance use disorders. 1
- The patient must demonstrate motivation and capability to follow medical recommendations. 1
Technical Considerations
Lead Configuration
- The patient had a successful trial with a 2-lead system, which is appropriate for this indication. 6
- Laminectomy-style electrodes placed in the thoracic region may achieve better long-term effectiveness than percutaneous leads for FBSS (average VAS decrease of 4.9 vs. 2.5). 2
- However, the specific lead type should be based on the trial configuration that provided significant benefit. 2
Complication Avoidance
- Proper lead anchoring technique is critical to prevent displacement and migration, which are the most common reasons for trial failure. 6
- The permanent implant should replicate the trial lead positioning that achieved significant pain relief. 6
Important Caveats
Alternative Considerations
- While SCS is indicated, be aware that peripheral nerve field stimulation systems (like Sprint PNS) currently have insufficient evidence for this indication and should not be substituted. 7
- Epidural adhesiolysis shows only short-term effects and is not a substitute for permanent SCS in patients with successful trials. 3
Post-Implant Expectations
- Patients should understand that SCS typically improves pain, physical function, and sleep quality, but complete pain elimination is uncommon. 3
- The significant benefit demonstrated during trial is the best predictor of long-term success. 1