Intra-ventricular opioids are useful for recalcitrant
pain due to tumors affecting the brachial plexus.
It requires the placement of a ventricular catheter
connected to a subcutaneous reservoir that can be
accessed.134
Neural blockade (see section on interventional
procedures) can sometimes control intractable pain
when all other therapies fail. Temporary block with a
local anesthetic is initially applied prior to a planned
neurolytic block to assess side effects as well as to
predict the likely outcome.