Spinal Cord Stimulation vs. Conventional Medical Management: A Prospective, Randomized, Controlled, Multicenter Study of Patients with Failed Back Surgery Syndrome (PROCESS Study).

Introduction.  Since its first application in 1967, numerous case series indicate that spinal cord stimulation (SCS) is an effective treatment for the management of failed back surgery syndrome (FBSS). However, only one randomized controlled trial has demonstrated that SCS provides more effective pain relief than re-operation and conventional medical management. The PROCESS randomized, controlled, multicenter trial aims to assess the clinical effectiveness and cost-effectiveness of SCS when added to conventional medical management compared to conventional medical management alone in patients with FBSS. Methods/Design.  A total of 100 FBSS patients with predominantly neuropathic leg pain will be recruited from 12 centers and randomized to receive either conventional medical management alone or in combination with SCS for a period of 24 months. Patients will be evaluated at 1, 3, 6, 9, 12, 18, and 24 months. At the 6-month visit, patients will be classified as successful (≥  50% pain relief in the legs) or unsuccessful (< 50% pain relief in the legs). If the results of the randomized treatment are unsuccessful, patients can cross over to the alternative treatment arm. Discussion.  This paper highlights the rationale, design, methods, and challenges of an ongoing prospective, randomized, controlled, multicenter clinical trial that has been undertaken to obtain conclusive evidence of the clinical efficacy and cost-effectiveness of an SCS system in patients with FBSS.