A Prospective, Multicentre Study of Low Dose Targeted Drug Delivery (TDD) for Chronic Back Pain Patients who have Failed Spinal Cord Stimulation

Spinal cord stimulation (SCS) is an advanced treatment option that can help to relieve chronic back pain. Not all who try SCS get pain relief. Sometimes the pain returns and SCS no longer helps. For these patients, an alternative option is to try targeted drug delivery therapy. Strong pain medication (typically morphine) is delivered directly to the space around the spinal cord by an implanted drug pump device. In this study, we recruited patients who “failed” SCS therapy to try “low dose” drug delivery therapy. Eligible patients were implanted with a drug pump and followed-up for 12-months. The study included nine patients. At 4-months, three patients reported at least 50% pain relief. Four patients left the study after this due to lack of pain relief or a medical problem. Of the remaining five patients, three patients reported at least 50% pain relief at the end of the study and said they were “much improved” or “very much improved”. During the study, 16 medical problems were recorded that were “probably” related to the study. These included pain or headache after the implant surgery, increased sweating, diarrhoea/constipation, and difficulty urinating. One patient had a serious medical problem that required hospital care (wound infection) and left the study. In conclusion, the study showed that some patients who have tried SCS therapy without success may get pain relief with targeted drug delivery therapy, however, further trials are needed.