The purpose of the spinal cord stimulator is to cause electrical stimulation of the dorsal columns of the spinal cord for the purpose of pain relief. This procedure has become increasingly popular as a treatment for neuropathic pain.
There are various complications of SCS. Here is a review of these:
It is the most common complication of spinal and peripheral nerve stimulation. The leads of the stimulator are placed in the epidural space in the spine near the region that supplies nerves to the painful area. The lead migration can be vertical or lateral. The overall rate of 13.2% has been reported for this complication.
It leads to paraesthesia coverage loss, which can be recaptured by reprogramming, but it may require minor reoperation to relocate the lead to its original position and most will incur the cost of a new lead.
Lead Fracture and Malfunction
Lead fractures and other hardware malfunctions occur sometimes as well. Lead breakage has been reported to occur in 9% cases approximately. A common site of fracture was distal to the fixation point to the deep fascia where the lead enters the spinal canal
The battery is located within the device and when it is depleted, a surgical procedure is required to replace it.
Battery failure occurs in almost 2% of cases according to one study. Usually, premature battery failures do not occur. Battery consumption depends on distance to the spinal cord, anatomical location and increased current drain, current intensity and the stimulation patterns. Rechargeable batteries were introduced, and have limited lifespans extending up to 10 years or so. The rechargeable batteries require a higher level of patient understanding and awareness. Implantation of a rechargeable system is indicated mainly when a cell-driven device lasts for less than approximately 4 years.
Another potentially unpleasant effect is a heating sensation that is felt over the stimulation during the process.
Patients may complain of pain around the implantation site or over the lead anchor site or lead extension junctions. The incidence for this complication has been reported at 12%.
Infection associated with these devices at a rate of 4% to 10%. It is a common cause for the explanation of the device. Almost half of these were caused by Staphylococcus and about 3% were due to Pseudomonas. Potential risk factors for infection or poor wound healing included diabetes, debilitated status, malnutrition, extremely thin body habitus, obesity, autoimmune disorder, corticosteroid use, decubitus ulcers, pre-existing infection, poor hygiene, urinary or fecal incontinence, etc. Infection prevention techniques include administration of prophylactic antibiotics, adequate skin preparation, meticulous attention to sterile techniques in the operating room, etc.
Skin erosion of leads or hardware is possible quite rare.
Accidental dural puncture is possible during epidural needle placement in lead positioning. It may lead to post-dural puncture headache symptoms and/or CSF leak into the wound. There may be associated symptoms of positional headache, diplopia, tinnitus, neck pain, photophobia, etc.
This can be caused by direct trauma – needle puncture, percutaneous lead placement, or during surgery for placement of paddle leads. In rare cases, it can result from epidural hematoma or abscess formation.
From this review, it is quite apparent that a competent specialist can significantly reduce the possibility of these complications. Selection of the best possible hardware requires a thorough knowledge and sound judgment. Proficiency in surgical skills should minimize implantation-related injuries and pain thereafter. Wound infection rates should also be minimal when adequate precautions are taken. Overall, it makes all the difference in the world if the right specialist is chosen for the job.