Spinal cord stimulation for chronic pain: causes of long-term paddle-lead failure.

Objectives.  This study is to evaluate long-term lead failure in spinal cord stimulation. Materials and Methods.  One hundred and seven patients with permanently implanted spinal cord stimulators were studied for 14 years. All suspected paddle-lead failures were studied prospectively using preoperative radiography and intraoperative electric interrogation. Lead failure was defined as complete loss of electric stimulation due to lead malfunction. Primary lead failure was defined as first lead failure after permanent implantation of a new lead and recurrent lead failure was defined as any lead failure after any lead replacement. Results.  Primary lead failure occurred in 14.9% and recurrent lead failure in 56.2%. Two (12.5%) of the primary failures and two (22.2%) of the recurrent failures were due to lead fractures. The mean time to primary lead failure was 37.9 months and to recurrent lead failure was 23.7 months. Conclusion.  The incidence of primary lead failure remains low at 14.9% in the long run, but it is a significant adverse risk factor for recurrent paddle-lead failure. Great care should be undertaken to prevent lead failures by appropriate anchoring.