This information is designed to help patients discuss their operation with their neurosurgeon. The specific benefits and risks of the operation must be reviewed directly with their surgeon.
These pumps contain a refillable reservoir of Baclofen (anti-spasticity medication) and are connected to a small tube which delivers the drug to the space around the spinal cord. The pump is about the size of a hockey puck and sits under the skin of the lower abdomen. The drug is delivered directly to where it is needed (around the spinal cord) and therefore has less systemic sedative side-effects. There is an approximately 4 to 1 concentration difference between the spinal cord (where the drug is needed) and the brain (where the drug causes side-effects) when the pump is used.
Candidates for this surgery should have lower limb spasticity that is interfering with their quality of life. They should either i) not be able to control their spasticity with their oral medications, or ii) not be able to tolerate the side-effects of the medications required to control their spasticity.
All patients considering surgery will have a test dose organized by the Baclofen Pump Clinic. This will be a small injection of Baclofen into their back through a lumbar puncture needle. This will place a dose of Baclofen into the fluid around the spinal cord and will be a very good indication of what it would be like to have the effects of a Baclofen Pump.
If patients get a good response from the test dose then they should consider surgery. If they do not get a good response from the test dose, they should avoid surgery.
The operation is performed under a general anesthetic at Vancouver General Hospital. Patients typically leave the hospital the next day.
Once the pump is in place under the skin of the abdomen, it holds about 6 months worth of Baclofen. The pump can be refilled as necessary by the Baclofen Pump Nurse. A small needle is used to go through the skin and into the pump and then refill the reservoir of medication. The dosage of medication released by the pump can be controlled with a computer in the Baclofen Pump Clinic. If you need more Baclofen it can be adjusted up or if you are have some side-effects, it can be adjusted down.
Baclofen will reduce the spasticity in your lower limbs. If your quality of life is reduced because of symptoms due to your spasticity, then the Baclofen pump will help you. Some symptoms that can be helped include the following:
1. difficulty sitting, transferring, toiletting, or cleaning because of extensor spasms,
2. painful spasms or spasms that interfere with walking
Baclofen will not make you stronger or improve your sensation. Occasionally patients use their spasticity to help transfer if their legs are weak. In those patients, Baclofen can actually worsen their transfers because they can no longer use their stiff, spastic legs as a brace to help transfer.
The two most common complications are infection and technical malfunction. Any wound infection must be treated with antibiotics (to cure it if possible) but also to prevent the infection getting deeper into the fluid around the spinal cord. An infection in this fluid is called meningitis and could be lethal if untreated. Since we began this operation a decade ago, I have not had any meningitis (although it is always a possibility) related to surgery. We have had technical malfunctions where the tube leading from the pump has become dislodged or blocked. This can be fixed with a new tube but it means another operation. We have had a patient develope a serious infection after a pump refill more than a decade after the original surgery.
There are other rare complications associated with this operation. I am aware of patients who have had spinal cord injury from this operation and sustained permanent neurological deficits.
Patients will be followed by the Baclofen Pump Clinic at GF Strong Hospital. The dosage of baclofen will be adjusted and refilled by the physiatry team at that hospital and not by the neurosurgery team. There are 3 rare but potential problems that patients and their families should watch out for.
1. Infection: Any fever that is accompanied by headache should be evaluated by your family doctor. If you have a stiff neck it could be a sign of meningitis and this needs to be treated in hospital.
2. Baclofen Withdrawl: If the delivery of baclofen is stopped or reduced for some reason (e.g. blocked catheter or defective pump), the patient may have a withdrawl syndrome. Patients may develope a variety of symptoms including: a dramatic increase in spasticity, as well as fever and seizures. This is an emergency and requires restarting the baclofen in hospital.
3. Baclofen Overdose: If too much baclofen is released at once (e.g. defective pump), the brain will be sedated by the drug. This can cause sedation and, if severe, the patients will be too comatose to breath. This requires emergency hospitalization.