Hardware failures in spinal cord stimulation for failed back surgery syndrome

Spinal cord stimulation (SCS) is an efficient means for treatment of the postsurgical lumbar spine condition known as failed back surgery syndrome (FBSS). Although the devices and the implantation techniques are well established and the technology is sophisticated, there are some complications caused by hardware failures. This study was aimed at identifying the most frequent types of hardware failures and their causes in FBSS patients treated with SCS. In a retrospective analysis, a group of 42 FBSS patients using single lead SCS for 6-74 months was evaluated. Only hardware failures were considered in the analysis, and parameters such as occurrence of failure after primary implantation of the device, frequency and site of failure, stimulation time to failure (TF), and overall time of SCS usage were recorded. In the patient group studied, 12 surgical corrections of the hardware were carried out in 10 patients. In eight patients there was a single corrective procedure, in two additional cases there were two surgically corrected hardware failures each. The most often encountered type of hardware failure was lead breakage or disruption of insulation (percutaneously placed Quad leads only) leading to short circuiting and dysfunction (n= 8). Second in frequency were receiver (model 3470) failures due to insulation leakage at the plug connection site (n= 2). In one case, extension cable breakage caused dysfunction of the system, and another dysfunction was caused by distal extension cable disconnection. In conclusion, SCS is a low-complication procedure for treatment of benign low-back pain, but seems to be prone to lead and insulation failures.