DAS Pump Placement
WHAT IS IT?
DAS stands for drug administration system. A DAS pump is placed in the body to administer medication into the spinal fluid. It is used to treat spasticity (muscle tightening), which can occur after severe central nervous system damage, and also to treat cancer pain. The drugs administered through the pump are usually Baclofen and Morphine. Medications such as these are tested prior to pump placement through a trial dose injection into the spinal fluid to check for effectiveness, sensitivities and side effects.
If the trial is successful, the physician will continue with surgical implantation. Normal pre-operation rules apply: all anticoagulants must be discontinued and there can be no eating or drinking before the surgery. There are usually two surgeons to make the process go smoothly and quickly. One incision is made in the lower back to place tubing into the spinal fluid. The tubing is placed through a needle with the use of x-ray guidance. The catheter is then secured to underlying tissues. A second incision is made on the left or right side of the abdomen, creating a pocket where the pump, about the size of a hockey puck, is placed. The catheter is then tunneled under the skin between the pocket and the lower back incision and the two incisions are closed off. The initial dose of medication is put into the pump prior to implantation and generally needs to be changed within the first few weeks. The surgery usually takes about 1 hour, but the patient is asked to stay overnight to watch for significant side effects.
WHO IS IT FOR?
Patients who have pain caused by spasticity or cancer pain and who respond well to the trial injection. The procedure can be expensive, so pump system insurance authorization is needed beforehand. Because refills are needed at 2-3 month intervals and all medication changes require a visit, this procedure is best suited for those who live near the clinic.
The main risk is infection, most commonly on the site of the pump pocket. In rare cases, the back incision can come infected resulting in severe spinal infections. There is minimal risk of bleeding. Some people may experience post-operative spinal headache that resolve spontaneously or are treated with an epidural blood patch.