Dorsal column stimulation is utilized to treat post-laminectomy pain/failed back syndrome.
Electrical signals are induced in the spinal cord (via an implanted system), blocking pain signals from ascending to the brain. The leads (impregnated into plastic paddle) are implanted via a thoracic laminectomy. The signal generator (to which the leads are secured) is implanted in the lateral lumbar region or flank through a second incision.
NOTE: A percutaneous trial is outpatient performed prior to implantation of the DCS system. This involves introducing wire (electrodes) into the epidural space (similar to an epidural injection). The leads are affixed to a signal generator that sends electrical impulses (inductively) into the spinal cord. The patient’s response to the provocative trial will determine his/her candidacy for the permanent implant.
- This procedure starts with an incision in the thoracic region.
- The paraspinal muscles are then elevated from multiple levels exposing the lamina (the bones that form the back of the spinal canal serving both protective and structural roles).
- The lamina and spinous processes are removed utilizing a variety of techniques. This exposes the covering of the spinal cord known as the dura.
- The electrodes (either embedded in a silastic paddle or free-form) are then placed on top of the dura and secured in place.
- A trial stimulation is then performed (intraoperatively*) to assure that the patient has adequate coverage of the described pain regions.
- A second incision is then made in the lumbar region or flank into which the signal generator/battery is implanted.
- Patients typically are mobilized on the night of surgery and discharged home the following day.
* The procedure is performed under spinal anesthesia and mild sedation, allowing for patient questioning during the procedure.
WHAT YOU WANT TO KNOW
“What is the primary indication for dorsal column stimulation?”
Post-laminectomy/failed back syndrome. Individuals experiencing persistent low back and leg pain in the wake of lumbar surgery (who have failed non-surgical options) are potential candidates for DCS. Leg pain tends to be better addressed (covered) than low back pain. That said, with advancements in technology (wider paddle leads with more electrodes and better microprocessors), we are now capable of covering low back pain in the majority of cases.
“How long do the trial leads stay in my back?”
The leads remain in place for 3-5 days during which time activity is limited (as to not cause lead migration or dislodgement).
“What are the risks of the procedure?”
Risks of the stimulator trial include spinal fluid leak and resultant headache, infection, and hemorrhage (bleeding) behind the spinal cord necessitating emergency surgery (rare). Those patients who receive the permanent implant assume those risks associated with thoracic surgery: infection, bleeding, paralysis, spinal fluid leak, lead migration/breakage necessitating reoperative surgery and failed pain coverage.
“Is there downtime after surgery?”
Patients are typically mobilized the morning after surgery. Lifting is restricted to 5 pounds for the first six weeks and thereafter liberalized. Normal activities (including driving) are typically resumed after 2 weeks. Patients will continue treatment with their pain management physician throughout the process.
“What are my chances of success? Will I remain on my typical pain medications after surgery?"
50-80% of patients (depending upon the literature source) will experience at least 50% reduction of preoperative pain. This will facilitate (and hopefully encourage) weaning of narcotic-based pain medications (typically prescribed for post-laminectomy/failed back syndrome). The weaning process will be supervised by the treating pain management physician.