A spinal infusion pump implant, commonly known as an intrathecal implant or morphine pump, is a specialized device, which delivers concentrated amounts of medication into the spinal fluid space via a small catheter. The intrathecal space is the sac that contains the spinal fluid. The spinal infusion pump is also known as an intrathecal infusion pump.
Spinal infusion pump implants are offered to patients with chronic and severe pain, who have not adequately responded to other, more conservative, treatments. Some examples of diagnoses for which a spinal infusion pump might be used include failed back syndrome, post-laminectomy syndrome, cancer pain, RSD, and severe osteoporosis or end-stage arthritis.
Usually these patients cannot be easily controlled on oral pain medications. Thus, to control their pain, these patients may benefit from a continuous spinal infusion of pain medication, usually morphine. Patients have to also meet certain other screening criteria before a spinal infusion pump is implanted.
The spinal infusion pump delivers concentrated amounts of medication into the spinal fluid, thus continuously bathing the pain receptors on the spinal cord with pain medication. This allows the patient to eliminate or substantially decrease the need for oral medications for pain. It delivers medication around the clock, thus eliminating or minimizing breakthrough pain and other symptoms.
Once all the criteria for a spinal infusion pump are met, the actual procedure in the operating room takes from 45 minutes to two hours.
The implantation of a spinal infusion pump is a surgical procedure that requires cutting of the skin. The patient procedure involves inserting an introducer needle through skin and deeper tissues. So, there is some pain involved.
However, the skin and deeper tissues are numbed with a local anesthetic using a very thin needle before inserting the larger introducer needle. Almost all of the patients have anesthesia or also receive deep intravenous sedation that makes the procedure easy to tolerate.
Depending on the patient, the spinal infusion pump and infusion catheter placement may be done under general anesthesia. This often depends on the general health condition of the patient. Otherwise, the placement of the infusion catheter is done under local anesthesia with patients mildly sedated.
The amount of sedation given generally depends upon the patient tolerance. Then for the tunnelling of the catheter and the infusion pump placement, patients are given stronger deeper intravenous sedation so that they usually will have no memory of this part of the surgery.
It is done with the patient lying on the side. Sometimes the tubing is placed with the patient in the prone position. The patients are monitored with EKG, blood pressure cuff and an oxygen-monitoring device. The skin is cleaned with antiseptic solution and then the procedure is carried out. X-ray is used to guide the introducer needle for inserting the infusion catheter.
Once the catheter is in good position, a plastic anchor is used to attach the infusion catheter to the spinal ligaments. Then a tunnel is made from the back to the lower abdomen with a special tunneling tool. A pocket under the skin is made in the lower abdomen into which the infusion pump will be placed.
The pump is filled with morphine and the catheter is attached to the pump. Once this is done, the incisions are sewn shut and bandages applied.
The spinal infusion catheter is inserted in the midline at the lower back. The infusion pump is then placed on the side of the abdomen in a pocket under the skin.
If the procedure is successful, you may feel that your pain may be controlled or quite less. The pump is adjusted electronically to deliver adequate amount of medication. The pump is usually activated while the patient is still on the operating table and usually will begin delivering medication within twenty minutes.
There will typically be some swelling over the pump site and tenderness or pain from the incisions. However, in many patients, this incisional pain and tenderness is controlled fairly well by the morphine infusion and may not require additional pain medication.
Most of the patients are kept overnight for observation and pump adjustment. Someone will need to drive the patient home. Patients going home the night of the surgery should not be alone the first night. All patients will be advised to take it easy for several days.
Ice may be used for swelling around the pump and some patients are asked to wear a soft abdominal binder as a sort of pressure dressing over the pump. Antibiotic pills are given to decrease the risk of infection. The physician will check the wound in about three to five days. If the wound is dry, the dressings will probably be removed at that time. The stitches will be removed in about two weeks or so.
The medication contained within the pump will last about 1 to 3 months depending upon the concentration and amount infused. It is then refilled via a tiny needle inserted into the pump chamber. This is done in the office or at your home and it takes only a few minutes. The batteries in the pump may last 3 to 5 years depending upon the usage. The batteries cannot be replaced or recharged. The pump must be replaced at that time.
It is sometimes difficult to predict if a spinal infusion pump will indeed help you or not. For that reason a trial of different doses of morphine injection into the spine is carried out to determine if a permanent pump would be effective to relieve your pain or not.
Generally speaking, this procedure is safe. However, with any procedure there are risks, side effects and possibility of complications. Bruising, soreness, swelling and other tenderness are very common. Headaches, tingling, short-term weakness or numbness caused by the catheter placement are much less common but do occur. Bleeding and infection are uncommon as are other serious complications.
Morphine is the only FDA approved pain medication that is officially recommended for a spinal infusion pump. Patients with side effects from morphine may opt to try other pain medications including Fentanyl, Dilaudid and Sufentanil. Also, certain other medications can sometimes be added to the narcotic pain medication to increase its effectiveness or to decrease the overall amount of narcotic pain medication that is needed.
MRIs, if truly necessary, can be performed with a spinal infusion catheter and infusion pump in place. Special protocols for pump patients can be given to the MRI technicians and radiologists. Most patients with a spinal infusion catheter and pump do not have MRIs.
Maybe. Depending on the sensitivity of the specific screening device, many patients can pass through with ease, just like some patients with pacemakers. If not, all patients are provided with identification indicating that a medical device has been implanted.
If you are on a blood thinning medication, if you have an active infection going on, or if you have poorly controlled diabetes or heart disease, you should not have the procedure or at least consider postponing it if postponing would improve your overall medical condition. Patients also have to meet certain other screening criteria before implanting the pump.
Videos about spinal infusion pumps are available from the office to borrow. More detailed information is available from the manufacturer of this device. Such information can be found at the Medtronic Web Site: www.medtronic.com.