Spinal Cord Stimulator
A spinal cord stimulator is an implanted device that sends low levels of electricity directly into the spinal cord to relieve pain. The concept works by scrambling the nerve signal before it travels back to the brain. A stimulator may be a possible answer for patients who have had previous back procedures yet still have some levels of lingering pain, or this may an option for a patient who does not want additional surgery on another level of the spine. The device consists of thin wires, or electrodes, and a small, pacemaker-like battery pack called the generator. The electrodes are placed between the spinal cord and the vertebrae and the generator is placed under the skin, usually near the buttocks or abdomen. Spinal cord stimulators allow patients to send the electrical impulses using a remote control when they feel pain. It works by replacing the sensation of pain with light tingling, called paresthesia. For patients who find this feeling uncomfortable, newer devices offer “sub-perception” stimulation that cannot be felt at all.
The best part of the device is that the patient will undergo a “trial period” to see if they like the stimulator and if it alleviates the pain enough to justify moving forward with the permanent implant. Before the trial even takes place, the spine surgeon will make sure that the patient will be a good fit for the device by ordering imaging tests to check for any spine instability and psychological screening. Some insurance companies require psychological screening to ensure disorders like depression or anxiety aren’t worsening the patient’s pain.
For the trial, the surgeon will implant a temporary device for patient’s to test out. Guided by a specific type of X-ray called fluoroscopy, the surgeon will carefully insert the electrodes in the epidural space of the spine. The location of your pain affects where these electrodes will be placed along the spine. The surgeon may ask for your feedback during the procedure to best position the electrodes. This trial procedure typically requires only one incision in your lower back to place the electrodes. The generator/battery will be outside the body, typically on a belt, you’ll wear around your waist. For about a week, the patient will evaluate how well the device reduces your pain. The trial is considered a success if you experience a 50% or greater reduction in pain level. If unsuccessful, the wires can easily be removed in the clinic without damage to the spinal cord or nerves. If successful, surgery is scheduled to permanently implant the device.
For the permanent implantation, the generator is placed underneath the skin and the trial electrodes are replaced with sterile electrodes. Unlike the trial electrodes, these will be anchored by sutures to minimize movement. The implantation can take about 1-2 hours and is typically performed as an outpatient procedure. After the local anesthesia has been administered, your surgeon will make one incision (typically along your lower abdomen or buttocks) to hold the generator and another incision (along your spine) to insert the permanent electrodes. The incisions are about the length of a business card. As in the trial procedure, fluoroscopy is used to determine where the electrodes are placed. Once the electrodes and generator are connected and running, your surgeon will close the incisions. The surgeon uses general sedation during this procedure because the permanent implantation will correspond with the placement used for the trial.
Implantation of an Intrathecal Pump:
An intrathecal pump is an effective way to deliver pain medication directly to the spinal cord area. By distributing the medication straight into the cerebrospinal fluid (CSF), the patient is able to benefit from significantly lower amounts of medicine than with traditional oral medications. This is an option of treatment for candidates who have not had success with traditional methods or procedures. Some examples of patients who may benefit from intrathecal pump implant include those suffering from the following conditions: failed back surgery , cancerous tumors that are compressing the spinal column, chronic pancreatitis, or other progressive diseases that result in sciatica or peripheral nerve pain.
The system uses a small pump that is surgically placed under the skin of the patient’s abdomen along with a catheter that is also surgically placed in the intrathecal, fluid-filled space around the spinal cord that contains CSF, area. The two devices are connected through a flexible, silicone tube that delivers the pain medication to the spine. A space inside the pump called the reservoir holds the medication, and it is programmed to slowly release it over a period of time. The pump can also be programmed to release different amounts of medication at different times of the day, depending upon changing needs. When the reservoir is empty, the doctor or nurse refills the pump by inserting a needle through the patient’s skin and into the fill port on top of the reservoir.