An external or implantable pump infuses a mixture of local anesthetic such as bupivacaine and an opioid such as morphine directly into the subarachnoid cavity between the spinal cord and its protective sheath.
It provides superior pain relief with reduced systemic side effects especially in refractory cancer pain patients.
Epidural catheter
Epidural space is filled with connective tissue, fat and blood vessels and crossed by the spinal nerve roots.
A long-term epidural catheter may be inserted into this space for three to six months, to deliver anesthetics or analgesics for pain relief.
A tunnel is made under the skin for the line/catheter carrying the drug to emerge at the front of the person. This process is called "tunneling". It is recommended for long-term use for reducing the chances of any infection at the exit site reaching the epidural space.
Spinal cord stimulation
Electrical stimulation of the dorsal columns of the spinal cord can produce pain relief.
Leads are implanted under fluoroscopy (X - ray) guidance. The generator is worn externally for several days to assess its efficacy. If pain is reduced by more than 50 percent, permanent implantation is done.
A small pocket is made beneath the skin of the upper buttocks, chest wall or abdomen and the leads are threaded under the skin from the stimulation site to this pocket, where they are attached to the snugly fitting generator.
It is much useful in neuropathic and ischemic pain type of pain than in cancer pain.
