Design issues of a randomised controlled clinical trial on spinal cord stimulation in critical limb ischaemia. ESES Study Group.

OBJECTIVES: Review of the design of a clinical study to evaluate of the efficacy of epidural spinal cord electrical stimulation (ESES) as compared to best medical treatment in patients with nonreconstructible critical limb ischaemia. DESIGN: Randomised controlled clinical trial of pragmatic type, which will be analysed according to the intention-to-treat principle. The treatment strategies are ESES, in addition to best medical treatment, and best medical treatment alone. Patients are followed-up for at least 18 months. SETTING: The ESES-trial is an ongoing multicentre trial in 17 hospitals in The Netherlands. PATIENTS: Patients with critical limb ischaemia, nonsuitable for either primary intervention or reintervention after failing reconstructions. CHIEF OUTCOME MEASURES: Limb survival, patient survival, quality of life and cost-effectiveness. MAIN RESULTS: From November 1991 until May 1994 120 patients had been enrolled. Using life-table analysis, at one year 76% of these randomised patients were alive: 41% without amputation and 35% with amputation. Quality of life of the trial patients was low, even compared to other severely ill patient groups, such as liver and heart transplant candidates. CONCLUSIONS: Considering the high incidence of death and amputation, 18 months of follow-up seems adequate to detect a clinically relevant outcome improvement from ESES-treatment, if present. We hope to present the results of this study at the end of 1995.