What is Drug Pump Implantation?
Drug pumps are implantable devices used to treat chronic pain and spasticity when medication or surgery has not been successful. Chronic pain is characterized by persistent, long-lasting pain that can last weeks, months, or even years. This condition may be brought about by cancer, arthritis, and nerve damage, although sometimes the cause cannot be determined. Spasticity is a disorder in which muscles become rigid and contract continuously, making arm and leg muscle control difficult. Stroke, cerebral palsy, multiple sclerosis, and injury to the brain or spinal cord can cause spastic muscles.
Once implanted, drug pumps deliver medication directly into the spinal canal using a thin, flexible tube (or catheter). The spinal canal can be accessed either intrathecally or epidurally. The intrathecal space is the fluid-filled space around the spinal cord, while the epidural space surrounds the outermost membrane that encloses the spinal cord.
Before you can have surgery to place a drug pump, you must first undergo a trial procedure to find out if the device will work effectively for you. There are two ways this trial can be performed:
- By injection, which uses a needle and syringe to administer small amounts of the medication into the intrathecal or epidural space. You may be given a single injection or multiple injections over a period of several days.
- By continuous infusion, which uses a catheter connected to an external drug pump to deliver medication intrathecally or epidurally. This method also takes place over a few days.
To implant a drug pump, a large needle and catheter are inserted into the spinal canal using X-ray guidance. Then, the pump is attached to the catheter and placed under the skin on the lower abdomen. The pump has a reservoir that needs to be refilled with medication at your doctor's office every four to six weeks.
Drug pump implantation takes about one to two hours and requires a hospital stay of one to two days. Short walks are encouraged during the first week after surgery, and normal activity can be resumed after about a week. To prevent the catheter from shifting out of place, you should avoid raising your arms above your head, sleeping on your belly, and lifting objects over five pounds for six to eight weeks.
Implanted drug pumps are associated with side effects and complications that could require more surgery. Spinal fluid can collect around the pump and cause headaches. These headaches usually go away on their own, but sometimes the fluid may need to be drained. Over time, the catheter could rupture or become disconnected, and the pump could stop functioning. These complications would require replacement of the defective part or removal of the device. Despite these possible issues, drug pumps offer benefits for patients with chronic pain or spasticity that oral pain relievers do not. Compared to taking medications by mouth, these devices relieve pain more effectively, improve patients' ability to perform daily activities, require lower dosages, and lead to fewer side effects.