Catheter-based Techniques for Terminal Cancer Pain: A Review of Nonneuraxial Interventions with Clinical Implications for End-of-Life Pain Management

Background: Evidence suggests that a significant proportion of terminal cancer patients have uncontrolled or inadequately controlled pain when using the World Health Organization (WHO) analgesic ladder approach. The use of interventional techniques has proven to reduce pain that is refractory to conventional methods. However, despite the use of well-established techniques (e.g., intrathecal drug delivery, celiac plexus blocks, etc), nonneuraxial, catheter-based techniques remain underutilized. Objective: The purpose of this narrative review is to examine the evidence for nonneuraxial, catheter-based techniques in treating terminal cancer pain, the barriers to implementation, and its role in bridging the gap between single shot techniques and surgically implanted devices. Study Design: This is a narrative review article summarizing case reports, case series, retrospective studies, prospective studies, and review articles published at any time frame on the use of nonneuraxial, catheter-based techniques for the treatment of cancer pain in the end-of-life setting. Setting: The University of Texas MD Anderson Cancer Center. Methods: A literature search was conducted from November 2020 to January 2021 using the PubMed database and keywords related to nonneuraxial catheters, terminal cancer pain, and hospice. All English-based literature published at any time frame involving human patients was included. Results: The number of studies referencing the use of nonneuraxial, catheter-based techniques for the treatment of terminal cancer pain is limited (n = 25). All of these studies were small, single-center, nonrandomized, noncontrolled case series and case reports. A total of 63 patients were evaluated across all studies, with the largest study involving 12 patients. The most common medication used was monotherapy with bupivacaine or ropivacaine and the longest duration of continuous catheter usage was 217 days. Of the studies that reported outcomes, the majority reported a reduction in pain. Very few studies reported catheter-related adverse events and tunneling appeared to be an important factor in reducing complications. Limitations: No studies were available comparing the use of nonneuraxial, catheter-based techniques to conventional systemic medical management. Further, the studies in this review were heterogenous and limited to a small sample sizes reported in case reports and case series only. Conclusion: Nonneuraxial, catheter-based techniques have the potential to play a significant role in the treatment of terminal cancer pain. Despite limited data, initial findings indicate that nonneuraxial, catheter-based techniques have the potential to bridge the gap between single shot interventions and surgical implanted devices by providing an effective, continuous therapy, with a lower risk profile.