Systematic Review of Intrathecal Infusion Systems for Long-Term Management of Chronic Non-Cancer Pain

Background: Disability, societal, and health impact of chronic intractable pain secondary to various failed therapies is a major issue. As advanced therapy, implantable therapies,which include intrathecal devices and spinal cord stimulation systems, are frequently usedin managing chronic intractable pain. Thus, continuous infusion of intrathecal medication isone of the methods used for the control of chronic, refractory, cancer, and non-cancer pain.However, despite the high costs of chronic non-cancer pain, it has been claimed that thereis a lack of evidence for intrathecal infusion systems and the cost effectiveness of these systems has been questioned in improving pain and function.Study Design: A systematic review of intrathecal infusion devices for chronic non-cancer pain.Objective: To determine the efficacy, utilization, safety, and complications associated withthe use of intrathecal infusion devices for long-term management of chronic non-cancerpain.Methods: Literature search was performed through EMBASE, Medline, Cochrane databases, and systematic reviews identified from 1966 to December 2008. Studies were thenreviewed and assessed using the Agency for Healthcare Research and Quality (AHRQ) criteria for observational studies and the Cochrane Musculoskeletal Review Group criteria forrandomized trials.The level of evidence was determined using 5 levels of evidence, ranging from Level I to IIIwith 3 subcategories in Level II, based on the quality of evidence developed by the U.S. Preventive Services Task Force (USPSTF).Outcome Measures: The primary outcome measure was pain relief (short-term relief≤ one-year and long-term > one-year). Secondary outcome measures of improvement infunctional status, psychological status, return to work, and reduction in opioid intake werealso utilized.Results: The level of evidence for intrathecal infusion systems indicated either Level II-3 orLevel III (limited) based on U.S. Preventive Services Task Force (USPSTF) criteria.Limitations: The limitations of this study include the paucity of literature, lack of qualityevidence, and lack of randomized trials.Conclusion: This systematic review illustrates Level II-3 or Level III (limited) evidence for intrathecal infusion systems for long-term relief in chronic non-cancer pain.Key words: Intrathecal infusion, intraspinal infusion, programmable infusion systems,spinal infusion, intra-spinal infusion devices, baclofen infusion, intrathecal opiates