Subcutaneous target stimulation (STS) in chronic noncancer pain: a nationwide retrospective study.

Stimulation of primary afferent neurons offers a new approach for the control of localized chronic pain. We describe the results with a new neurostimulation technique, subcutaneous target stimulation (STS), for the treatment of chronic focal noncancer pain. STS applies permanent electrical stimulation directly at the painful area via a percutaneous-placed subcutaneous lead. We reported the clinical outcomes of 111 patients with focal chronic, noncancer pain treated with STS in this first nationwide, multicenter retrospective analysis. The indications for STS were low back pain (n = 29) and failed back surgery syndrome (back pain with leg pain) (n = 37), cervical neck pain (n = 15), and postherpetic neuralgia (n = 12). Pain intensity was measured on a numerical rating scale (NRS) before and after implantation. Data on analgesic medication, stimulation systems, position, and type of leads and complications were obtained from the patients' records. After implantation, the mean pain intensity improved by more than 50% (mean NRS reduction from 8.2 to 4.0) in the entire patient group (P = 0.0009). This was accompanied by a sustained reduction in demand for analgesics. In all the patients, the STS leads were positioned directly at the site of maximum pain. Lead dislocation occurred in 14 patients (13%), infections in 7 (6%), and in 6 cases (5%), lead fractures were observed. The retrospective data analysis revealed that STS effectively provided pain relief in patients suffering from refractory focal chronic noncancer pain and that STS is an alternative treatment option. Prospective controlled studies are required to confirm these retrospective findings. This article presents a new minimally invasive technique for therapy-resistant focal pain.

Safety of prolonged sacral neuromodulation tined lead testing.

OBJECTIVE: Prolonged sacral neuromodulation (SNM) testing is more reliable for accurate patient selection than the usual test period of 4-7 days. However, prolonged testing was suspected to result in a higher complication rate due to infection via the percutaneous passage of the extension wire. Therefore, we prospectively assessed the complications associated with prolonged tined lead testing. PATIENTS AND METHODS: A consecutive series of 44 patients who underwent prolonged tined lead testing for at least 14 days between May 2002 and April 2007 were evaluated. Complications during prolonged tined lead testing, during and after tined lead explantation and during follow-up after implantation of the implantable pulse generator (IPG) were registered prospectively. RESULTS: Four patients suffered from urgency-frequency syndrome, 13 from urge incontinence, 18 from non-obstructive chronic urinary retention and nine from chronic pelvic pain syndrome. The median test phase was 30 days (interquartile range [IQR] 21-36). Thirty-two of the 44 patients (73%) had successful prolonged tined lead testing and 31 of these (97%) underwent the implantation of the IPG. The median follow-up of the IPG implanted patients was 31 months (IQR 20-41). The complication rate was 5% (2/44) during prolonged tined lead testing and 16% (5/31) during follow-up of the IPG implanted patients, respectively. None of the complications could be attributed to prolonged testing. No infections were observed during the study period. CONCLUSIONS: This prospective, observational non-randomised study suggests prolonged SNM tined lead testing is a safe procedure. Based on the low complication rate and the increased reliability for accurate patient selection, this method is proposed as a possible standard test procedure, subject to confirmation by further randomised, controlled clinical studies.