Short test-period spinal cord stimulation for failed back surgery syndrome

The aim of this study was to investigate the effects of spinal cord stimulation (SCS) on patients with chronic pain due to failed back surgery syndrome and to evaluate selection criteria for predicting SCS success. Thirty-two patients were enrolled in the present study. Prior to test implantation, all of them have been screened with various pain questionnaires and were selected for the SCS procedure according to stringent criteria. The single-electrode neurostimulators Itrel II and Xtrel were used with percutaneously inserted leads. The leads were placed under X-ray image intensifier control, and position was modified until optimum paresthetic coverage of pain areas was achieved. Twenty-nine of the 32 test stimulation patients reported on a pain reduction of at least 50% and up to 90% of preimplantation values. After a test period of 24 to 72 hours, internalization of the whole SCS system followed. In 3 cases the lead was explanted after 3 days of test stimulation because of insufficient analgesic effect. No major complications were seen in this highly preselected group. Follow-ups of 2 to 3.5 years after lead implantation proved stable analgesia and good outcome in 25 patients. Further 4 patients experienced a late failure of the system due to decreased analgesic effects of SCS. In conclusion, if the selection of SCS candidate patients is performed very carefully and according to well defined criteria, test stimulation periods can be kept relatively short, thus reducing therapeutic failures, risk of infection, and costs of therapy.