Tunneled epidural catheters involve a pain
management technique whereby there is long
term infusion of medications into the epidural
space.  Typically these catheters are implanted
in cancer patients who have an estimated time
of survival of less than 3 months.  They require
either an external pump device for continuous
infusion or a subcutaneous implanted port for
intermittent delivery of long acting medications.
Whereas they are quite effective in controlling
most cancer related pain, they are prone to
the development of infection on occasion and
must be monitored for infection at the skin
insertion site.  Also, in patients with cancer
that has infiltrated the epidural space, there
may be a limited time in which the catheter may
be functional due to occlusion of the epidural
space by tumor.  But overall aside from the
above problems and occasional catheter
tip migration, the system works very well.  
  There are some patients without cancer who may benefit
from implantation of such a catheter system such as those
with prolonged post operative pain from a thoracotomy and
lung resection or in those who are too sick to take oral
narcotics for fear of respiratory depression and sedation.
     The procedure is fairly straight forward:  accessing the
epidural space with a needle, threading a catheter through the
needle into the epidural space, an incision made around the
needle, passing a tunneling device under the skin, passing the
catheter from the incision through the tunneling device to exit
the skin away from the spine (helps reduce infection risk), and
securing the catheter to the skin.  This is usually performed
under sedation or general anesthesia.
     Risks of the procedure include bleeding, infection, nerve
injury, inadequate tip placement.  Long term complications
include possible infection of the skin or epidural space,
reduced effectiveness due to cancer infiltration or tip
migration, etc.
     Alternatives include intrathecal infusion pump implantation.
Click on pics
below to enlarge

Tunneled Epidural Catheter
Drawing of
infused into the
epidural space
diffuse to all
parts of the
spinal canal