Long-term efficacy of partial splenic embolization for the treatment of steroid-resistant chronic immune thrombocytopenia.

Thrombopoietin-receptor agonists have been recently introduced for a second-line treatment of immune thrombocytopenia (ITP). Splenectomy has tended to be avoided because of its complications, but the response rate of splenectomy is 60-80% and it has still been considered for steroid-refractory ITP. We performed partial splenic embolization (PSE) as an alternative to splenectomy. Between 1988 and 2013, 91 patients with steroid-resistant ITP underwent PSE at our hospital, and we retrospectively analyzed the efficacy and long-term outcomes of PSE. The complete response rate (CR, platelets > 100 × 109 /L) was 51% (n = 46), and the overall response rate (CR plus response (R), > 30 × 109 /L) was 84% (n = 76). One year after PSE, 70% of patients remained CR and R. The group with peak platelet count after PSE ≥ 300 × 109 /L (n = 29) exhibited a significantly higher platelet count than the group with platelet count < 300 × 109 /L (n = 40) at any time point after PSE. The failure-free survival (FFS) rates at 1, 5, and 10 years were 78, 56, and 52%, respectively. Second PSE was performed in 20 patients who relapsed (n = 14) or had no response to the initial PSE (n = 6), and the overall response was achieved in 63% patients. There were no PSE-related deaths. These results indicate that PSE is a safe and effective alternative therapy to splenectomy for patients with steroid-resistant ITP as it generates long-term, durable responses.