The Rate of Infectious Complications After Intrathecal Drug Delivery System Implant for Cancer-Related Pain Is Low Despite Frequent Concurrent Anticancer Treatment or Leukopenia.

Background: The efficacy of intrathecal drug delivery (IDD) for cancer-related pain is well established. Cancer therapies are often associated with immunosuppression and increased risk of infection, and the rate of infection after intrathecal drug delivery system (IDDS) implant in cancer patients has been reported as 2.4%-6.3%. Our objective is to report on the rate of surgical site infections (SSI) in patients implanted with IDDS for cancer-related pain and to provide a data-driven discussion on the relationship between antineoplastic treatment, leukopenia, and other clinical or demographic characteristics and SSI.

Methods: Following local institutional review board approval, we conducted a retrospective chart review of IDDS implants from May 2014 through December 2018. Data collected included demographic data, health status, prophylactic antibiotic administration, surgery duration, presence of leukopenia (white blood cell [WBC] count of <4.0 K/µL) or moderate neutropenia (absolute neutrophil count [ANC] of <1000/μL) within the 30 days before IDDS implant, and details of antineoplastic treatment or systemic corticosteroid use in the perioperative period. This information was assessed in relation to SSI incidence up to 6 months following implant.

Results: Two hundred seventeen IDDS implants were identified. A majority of patients (79.3%) received ≥1 form of antineoplastic therapy within 30 days before or after implant, and 42.4% received multiple forms of antineoplastic therapy. Therapies included chemotherapy in 46.5%, immunotherapy in 28.6%, systemic steroids in 32.3%, and radiation therapy in 28.1%. One-quarter of patients (25.8%) were leukopenic within 30 days before implant, with 3.2% having moderate neutropenia. There were 2 infectious complications representing an infection rate of 0.9% (95% CI, 0.1%-3.3%), with limited shared characteristics between those experiencing SSI.

Conclusions: SSI risk after IDDS placement for cancer pain is low, despite frequent concurrent antineoplastic therapy and leukopenia in the perioperative period. Concomitant cancer therapies should not be a barrier to the implementation of IDD for cancer pain.