CIO 2022-27 Partial Splenic Embolization in Patients with Severe Thrombocytopenia and Extreme Splenomegaly

Purpose: Patients with severe thrombocytopenia and extreme splenomegaly are at imminent risk of major life-threatening bleeds and are usually unresponsive to platelet transfusions secondary to their massive splenomegaly. This study aims to evaluate the safety and efficacy of partial splenic embolization in patients with severe thrombocytopenia and extreme splenomegaly to improve platelet count.

Methods: This IRB approved single institution retrospective study included 11 patients (9 male, 2 female, average age 66.1±8.3 years) who underwent partial splenic embolization between March 2016 and July 2021. Patients were included if they had at least 5x larger spleen volume than the expected spleen size based on patient’s gender and height1 and had platelet count less than 30,000/uL at the time of the procedure. All embolization procedures were performed from left radial access using 300-500 um embolization beads. Medical records and imaging data were reviewed to evaluate splenic volumes, platelet counts, overall survival (OS) and complications.

Results: The mean platelet count pre-splenic embolization was 13,800±9,600/uL (range 1,000-30,000); 5 patients had platelet count < 10,000/uL. The mean splenic volume was 2135.1±998.4 cm3 and the mean splenic volume/expected splenic volume ratio was 13.6±6.3. Follow-up imaging showed 55.3±27.5% post-embolization infarct volume. 4 patients platelet count increased from 15,250±13,773/uL to 126,750±66,908/uL, 4 patients responded to platelet transfusions and 3 patients died soon after the procedure without platelet count increase. The 30-day mortality was 27% (3 patients). Median OS was 73 days (95% CI: 42-104) from embolization. There was no procedure-related bleeding complications. 3 patients had moderate pain, 2 patients had severe pain, 1 patient had small bowel obstruction, 1 patient had lower extremity edema and 2 patients had sepsis post-embolization.

Conclusion: Splenic embolization from radial access is safe and feasible in patients with severe thrombocytopenia and extreme splenomegaly. The procedure improved platelet count or response to platelet transfusions in 73% of patients, eliminating the risk of major spontaneous hemorrhage. The median OS was poor, which was due to underlying comorbidities. Further study is needed to clarify indications for splenic embolization in these extreme conditions.