Uncommon indications in chronic pain for intrathecal drug delivery systems: a narrative review of the literature.

Abstract

Intrathecal drug delivery systems (IDDS) have been used successfully for a number of refractory chronic pain conditions. The most common pain indications for the use of IDDS include cancer-related pain and postlaminectomy syndrome. IDDS can also be used to treat a variety of other less common refractory pain conditions, including central neuropathic pain, peripheral neuropathic pain and craniofacial pain. The aim of this article was to review the existing literature on the efficacy and clinical utility of IDDS for the management of uncommon pain indications, including spinal cord injury-related pain, transverse myelitis, diabetic painful neuropathy, postherpetic neuralgia and craniofacial pain to inform clinicians on the state of the current evidence of IDDS use in these challenging pain conditions. PubMed, Embase, Web of Science, CINAHL and Cochrane databases were searched with keywords. Additionally, reference lists of retrieved articles and relevant reviews were manually screened to identify additional publications. Articles were screened for relevance using Covidence by three reviewers. Eligible studies included the use of IDDS for refractory uncommon pain conditions. Exclusion criteria included non-English studies, animal studies, studies that focused on non-pain indications and abstracts without accompanied full text. Given heterogeneity and largely descriptive data, findings were analyzed narratively by descriptive categories.The use of IDDS for refractory pain in patients with select pain conditions is supported primarily by observational studies and small clinical trials. Current evidence suggests that the IDDS may provide meaningful analgesia in carefully selected patients with central and peripheral pain, and facial neuropathic pain; however, the magnitude of pain relief and durability of response is variable. These findings are likely reflective of the limited evidence as a result of selective utilization of this therapy in clinical practice. Based on limited evidence, IDDS may provide meaningful clinical benefit in patients with refractory uncommon pain syndromes. Future research can help to define the use of IDDS in this challenging patient population.