Intrathecal drug delivery is a mode of analgesic delivery that can be considered in those
experiencing both refractory pain and excessive side effects from opioid and adjuvant analgesic
use. Delivery of analgesic agents directly to the cerebral spinal fluid allows binding of the
drug to receptors at the spinal level. Therefore, a reduced analgesic dosage can be afforded,
resulting in reduction of drug side effects due to decreased systemic absorption. Drug delivery
into the intrathecal space provides this benefit, yet it does not eliminate the possibility of drug
side effects or risks of complications.
Complications from this route of administration may be seen in the perioperative period or
beyond, including infection, inflammatory mass, bleeding, and catheter or pump dysfunction,
among others. This may manifest as new/worsening pain or as a neurologic deficit, such as
a sensorimotor change and bladder/bowel dysfunction. Urgent evaluation with a detailed
physical examination, device interrogation, and other workup including imaging is called for
if symptoms suspicious for device-related problems arise. For the cancer pain patient, the
underlying malignancy should also be considered as a potential cause for these new symptoms
after intrathecal system implantation.
We present 2 such cases of complications in the cancer pain patient after intrathecal drug
delivery due to progression of the underlying malignant process rather than to surgical or
device-related problems. The first patient had a history of metastatic osteosarcoma who,
shortly after undergoing an intrathecal drug delivery trial with external pump, presented with
new symptoms of both pain and neurologic changes. The second patient with a history of
chondrosarcoma developed new symptoms of pain and sensorimotor change several days
after intrathecal drug delivery system implantation.
Key words: Intrathecal analgesia, intrathecal drug delivery, perioperative complications,
cancer pain, malignant pain, pain pump