Durability of partial splenic artery embolization on platelet counts for cancer patients with hypersplenism-related thrombocytopenia

Purpose: Partial splenic artery embolization (PSAE) has shown promise in increasing platelet counts in cancer patients with hypersplenism-related thrombocytopenia. The purpose of this study was to identify response predictors and to longitudinally evaluate PSAE efficacy and durability in a large cohort of cancer patients with hypersplenism-related thrombocytopenia. Methods: A single-institution, IRB-approved, HIPAA-compliant retrospective review of all PSAEs for thrombocytopenia between 2012 and 2015 was performed. Patients were classified as complete responders (CR, no platelet value < 100 × 10⁹/L following PSAE), partial responders (PR, initial increase in platelets but subsequent decrease in platelets < 100 × 10⁹/L), and non-responders (NR, platelets never > 100 × 10⁹/L following PSAE). Results: Of the 98 patients included in the study, 58 had CR (59%), 28 had PR (29%), and 12 patients had NR (12%). The percent splenic tissue embolized was significantly greater in the CR group compared to the PR group (P = 0.001). The percent volume of splenic tissue embolized was linearly correlated with the magnitude of platelet increase without a minimum threshold. At least one line of chemotherapy was successfully restarted in 97% of patients, and 41% of patients did not experience recurrence of thrombocytopenia for the duration of their survival. The major complication rate was 8%, with readmission following initial hospitalization for persistent “post-embolization syndrome” symptoms the most common. Conclusions: In cancer patients with hypersplenism-related thrombocytopenia, PSAE is a safe intervention that effects a durable elevation in platelet counts across a range of malignancies and following the re-initiation of chemotherapy.