Efficacy of transverse tripolar stimulation for relief of chronic low back pain: results of a single center.

Publication Information

Author(s): Slavin KV, Burchiel KJ, Anderson VC, Cooke B.
Journal: Stereotact Funct Neurosurg
Volume, issue, pages: 73(1-4):126-130
Year: 1999
PubMed Link: http://www.ncbi.nlm.nih.gov/pubmed/10853117

Study description

Study design: Case study
Study question: How effective is transverse tripolar SCS in relieving low back pain?
Population assessed: Human. Implanted.
Patient protection: IRB; informed consent
Outcome measures: VAS; Oswestry Low Back Pain Questionnaire; complications
Statistical significance: P < 0.05 (assumption)
Statistical analyses performed: Paired t-test

Patient selection

Diagnosis required: Yes
Psychological evaluation: Most

Demographic / prognostic factors

Sex (male/female): 6 male; 4 female
Mean patient age in years (+/- SD, range): 49 +/- 7 (38 to 58)
Number prior surgeries difference in outcome: # = 0 to 14 (median 2); outcome difference not reported

Pain location

Back and leg(s): 10
Unilateral: 4
Bilateral: 6

Pain characteristics

Pain duration years (mean +/- SD, range): 9.5 +/- 7.5
Neuropathic: 10

Indications (trial/implant)

Failed back surgery syndrome: 5
Diabetic neuropathy: 1 (plus degenerative disease)
Post-traumatic pain: 2 (spine; knee)
Spinal cord injury: 2 myelopathy (herniated disc; ossification of ligament)

Screening trial

Number patients who underwent trial: 10 (2 repeat implant)
Trial electrode type: All electrodes placed ready for chronic use.
Trial technique: Hemilaminectomy approach; patient prone
Pain control during trial: IV sedation and local anesthesia
Trial success criteria: Failure was defined as inadequate pain relief
Trial duration (days): 6 to 11 days

Stimulation

Paresthesia coverage: 4 of 9 needed electrode repositioned to increase overlap (3 at time of final implantation)

System implantation

Number implanted: 9
Type(s) of implanted electrode(s): Transverse tripole (TTP)
Anesthesia: IV sedation and local anesthesia
Electrode implantaton method: Hemilaminectomy approach; patient prone
Electrode location(s): T 8-T9 to T12-L1 and within 2mm radiographic midline.
Type of IPG: 4 = RF and 5= ITREL-3 pulse generator attached to trial electrode under general anesthesia after passed trial

Outcomes

Number in study: 10
Number followed: 7 'longer term'
Number with stimulation complication: 8 (including 4 repositioned electrode)
Answer to study question: Only 3 of 9 using SCS at 'latest' FU. Concluded that 'low back pain is not particularly responsive' to SCS with TTP

Outcomes: pain

Poor overall relief: Low back VAS decreased 26% (not significant)
Discontinued no therapeutic benefit: 3 explanted

Other beneficial outcomes

Change in activities of daily life: Disability did not improve significantly.

Biological complications

Infection leading to system explant: 1
Generator pocket hematoma: 1
Skin erosion or wound dehiscence treated: 1

Device complications

Other hardware failure: 1 malfunction corrected with intervention

Stimulation side effects

Postural changes: 4 considered problematic

Cost effectiveness

Faculty and staff

Facility location: USA
Facility type: University hospital

Data extraction information