Spinal cord stimulation in chronic pain: evaluation of results, complications, and technical considerations in sixty-nine patients.

Sixty-nine patients undergoing spinal cord stimulation (SCS) were studied for a period of up to 8 years. Indications, implantation techniques, and stimulation systems are presented in this article. Pain-suppressor effects of SCS are reviewed, assessing the clinical efficacy over time as well as complications with the stimulation device. Immediately following implantation, inadequate pain relief was noted in 20% of the patients. Decrease of the efficacy of pain alleviation occurs during the first 3 years after implantation. Most failures are noted in patients presenting with failed back surgery. This study also demonstrates that SCS systems should offer the capability of both monopolar and bipolar stimulation modes by the use of multipolar electrodes.