The aim of this study was to describe the adverse events relating to spinal cord stimulators reported to the TGA between July 2012 (start date of the TGA’s searchable database of notifications) and January 2019. The TGA’s data are voluntarily reported by patients or healthcare providers and therefore do not contain all safety data relevant to a device and cannot be used to determine absolute risk. An alternate source of information on safety is the notifications of adverse events made to government regulators such as Australia’s Therapeutic Goods Administration (TGA). 12 Long-term safety data could be derived from long-term observational registries but currently none exist. 11 A recent trial examining 2 types of stimulators followed participants for 12 months and found that 67% had an adverse event with 13% experiencing a serious adverse event. A narrative review reported average lead migration rates of 15.5%, device malfunction of 6.4%, and infection of 4.9%. 10Įvidence for the long-term safety of spinal cord stimulators is also lacking. Uncertainty about the efficacy of spinal cord stimulators is also reflected in guideline recommendations some guidelines endorse their use 4, 6 whereas others do not. 5 Other trials by Kapural et al, 7 Kumar et al, 8 and Deer et al 9 commonly cited as evidence of efficacy of spinal cord stimulators only compared different types of regimens or stimulation levels without a placebo control and therefore do not provide information about their efficacy. No trial had a treatment regimen beyond 3 weeks, and some were as short as 12 hours. 5 Effects on pain across individual trials were as large as 4 units to as low as zero units, with larger effects seen in studies at high risk of bias. 5, 6 A 2020 systematic review of 8 small randomized placebo-controlled trials (n = 185) reported a pooled effect on neuropathic pain of −1.15 points (95% confidence interval, −1.75 to −0.55) on a 0- to 10-point pain scale. The efficacy of spinal cord stimulators is uncertain because available trials are small, typically at high risk of bias and test brief treatment regimens. 2 Their use for the last 3 indications is not common in Australia. 2– 4 They are commonly used for intractable back pain such as failed back surgery syndrome but are also used to treat other painful conditions including complex regional pain syndrome, angina, ischemic leg pain, and peripheral neuropathy. 1 They are promoted as providing long-term pain relief, particularly when other interventions including surgery have failed.
1 The impulses interfere with how nociceptive signals are interpreted by the brain.
Spinal cord stimulators are devices implanted under the skin, which deliver electric impulses via leads placed in the epidural space.