Introduction: The incidence of failed back surgery syndrome is about 40%. We studied the efficacy of and patient satisfaction with use of a spinal cord stimulator to treat this syndrome.
Material and methods: A period of 72 months of experience with implanted spinal cord stimulators was analyzed in this observational, descriptive study of patients who were included retrospectively. Patients met criteria for failed back surgery syndrome according to the taxonomy of the International Association for the Study of Pain. A chi2 test was used to compare qualitative variables. Results for quantitative variables were compared by analysis of variance. Statistical significance was set at P < 0.05.
Results: Thirty-four patients were studied. Both lumbar back and radicular pain assessed on a visual analog scale (VAS) decreased significantly from the mean overall score of 6. As time passed, fewer patients felt the system met their expectations. More patients said the system met their expectations in the first months after implantation (73.5%) than at a later interview (55.9%). Seventeen complications were reported, the most common being mechanical difficulties with the implanted stimulator. None of the complications were serious. Use of additional medication to control pain decreased in 38.2% of the cases. A total of 73.5% of the patients considered the implanted stimulator to be beneficial and 67.6% would have a spinal cord stimulator implanted again.
Conclusions: Spinal cord stimulation improves lumbar back pain in patients with failed back surgery syndrome and reduces the amount of additional medication taken to control pain. It is important for patients to adjust their expectations about the implanted stimulator.