I went a looking for you, discovering an historical to present day article here http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2080496/ which tends to demonstrate a single catheter approach from a single pump. A number of meds, approaches, and uses are described, the most effective being for the management of pain associated with cancer. Yes, the article demonstrates positioning of the catheter into the spinal space and it would seem such an approach may bring systemic aid as in our oral ingestion of meds discussed on the forum for pain management.

God Bless,
Mark56