Retrospective Analysis of Intrathecal Drug Delivery: Outcomes, Efficacy, and Risk for Cancer-Related Pain at a High Volume Academic Medical Center

Abstract

Cancer pain is common and difficult to treat, as conservative medical management fails in approximately 20% of patients for reasons such as intolerable side-effects or failure to control pain. Intrathecal drug delivery systems (IDDS), while underutilized, can be effective tools to treat intractable cancer pain. This study aims to determine the degree of pain relief, efficacy, and safety of patients who underwent IDDS implantation at a multidisciplinary pain clinic. A retrospective review was conducted of patients with an intrathecal pain pump implanted for malignant pain. Charts were reviewed for demographics, cancer type, pain scores before and after implantation, and intrathecal drugs utilized. A Wilcoxon Signed-Rank test was conducted on the paired differences of pain scores before and after implant. A regression analysis was conducted using a linear model to assess effects of demographic variables on change in pain scores. 160 patients were included in analysis. The median pain score was 7.1 at time of implantation and 5.0 at one-month postimplantation. For patients with both baseline and one-month pain scores available, the median decrease in pain was 2.5 (p < 0.0001). Pain scores three-month postimplantation did not significantly differ from one-month postimplantation. Median longevity was 65 days. Five patients had pumps explanted due to infection with a median time to pump extraction of 28 days. IDDS has the potential to improve cancer pain in a variety of patients and should be strongly considered as an option for those with cancer pain intractable to conservative medical management.