Permanent implantation of a spinal cord stimulator is similar in many ways to the trial period. A major difference is the implantation of the generator. The technology being used for spinal cord stimulation is changing rapidly, but this is a typical process:
- Local anesthesia is applied to the injection site and the patient is sedated.
- The doctor inserts a hollow needle into the area around the spinal canal called the epidural space, guided by fluoroscopy (a type of X-ray). The needle contains thin, insulated wires, called leads, with electrical contacts attached. A small incision may be needed to insert the needle.
- Part of the lamina, a small bone covering the back of the spinal cord, may be removed to allow room for placement of the permanent leads via the hollow needle.
- The permanent leads are implanted. (In some cases, permanent leads were used for the trial period, making this step unnecessary.)
- The patient is awakened, and the doctor and patient work together again to ensure the optimal placement of the electrodes. When coverage of the painful areas is complete, the leads are fixed in place, and the patient is again sedated.
- A small incision is made where the generator will be placed.
- The generator is implanted under the skin. It is usually placed in the abdomen, upper buttocks, or upper chest. Generators range in size, with the largest ones about the size of a stopwatch. Comfort is a consideration in the generator’s location, and the doctor may ask the patient in advance about the best area. A person who usually sleeps on her right side, for instance, may prefer to have the generator on the left side. (Some rechargeable generators can be left in the body for many years, but the generator will probably need to be replaced at some point, requiring a new surgical procedure.)
- Wires are tunneled from the leads to the generator and connected, enabling the current to flow when the controller is turned on later.
- The incision is closed and the person begins recovery.
As with any surgery—even a minimally invasive one—the initial recovery period following spinal cord stimulation implantation can be painful. Light activities can often be resumed after two to three weeks, but complete recovery may take six to eight weeks. To avoid movement of the leads, certain physical activities will be limited for about three months.
Opioids may be used for two to four weeks to treat postoperative pain, but because of the potential for addiction and the likelihood of side effects such as constipation, it’s best to use them for as short a time as possible.
Asking the doctor to describe the usual amount of swelling on the back can be helpful, since the incision site is usually difficult for the patient to see clearly. A friend or family member can check the area periodically or the patient can use a mirror.
Some people can feel a small bump where the generator is implanted, but it is not likely to be visible over clothing. There is considerable variation in generators, with a strong trend toward smaller devices.
Learning How the SCS Device Works
While the controller will probably be ready for the individual to use right away, it may be more comfortable to wait until the surgery-related swelling goes down.
Controllers should be taken along when leaving the house. As a precaution, it can be helpful to teach family members or a close friend how to turn off the controller in case the person is not able to reach it for any reason. Some doctors recommend that people turn off the controller when driving.
Rechargeable devices continue to provide stimulation when they are charging; stimulation does not need to be turned off. In some cases, a specially designed belt holds the charger in place against the skin and over the implant during recharging.