Abstract No. 376 Partial Splenic Artery Embolization in the Management of Thrombocytopenia Using Ethylene Vinyl Alcohol Copolymer (Onyx): A Single-Center Experience

To describe the short and long-term efficacy as well as the safety of Onyx Liquid Embolic in the management of thrombocytopenia. A retrospective review of patients with portal hypertension who underwent partial splenic artery embolization (pSAE) for the management of thrombocytopenia with Onyx (Medtronic, Minneapolis, USA) as the single embolic to the splenic artery was performed. Platelet values (PLTs) were collected from immediately preceding the procedure, within 3 months following the procedure (early group), and 6-12 months following the procedure (late group). A right-tailed T-Test was then performed between the pre-procedure group vs early follow-up, vs late follow-up, and early group vs late group with an alpha value of 0.05. Finally, a retrospective review was performed evaluating for complications of the procedure. A total of 25 patients were treated with Onyx from 2019 to 2023. The average age was 62.4 years old (SD 10.2) and were 48% male. Of the initial 25 patients, 24 patients had follow-up within 3 months of the procedure and 14 patients had follow-up within 6-12 months. The remaining patients were lost to follow-up or deceased. The average PLTs in the pre procedure group was 69.5 (SD 35.2), in the early follow up group was 178.5 (SD 149.8), and in the late follow up group was 158.4 (SD 95.8). There was a statistically significant increase in PLTs between pre-procedure vs the early follow up groups [t(47) = 3.47, p < 0.01] and the pre-procedure vs the late follow up groups [t(37) = 3.34, p < 0.01]. There was no significant difference between the early follow up and late follow up groups [t(36) = 0.51, p = 0.31]. Within 30 days of the procedure, 13 patients (52%) experienced post-embolization syndrome, categorized as mild adverse events per Society of Interventional Radiology criteria and comparable to reported complication rates. Additionally, one patient was noted to have small volume hemoperitoneum that was managed conservatively, also considered a mild adverse event. Partial splenic artery embolization using Onyx is safe and effective, resulting in statistically significant increases in PLTs which appears to persist in the 6-12 month follow up cohort.