Comparative evaluation of two resorbable microparticles in a porcine kidney model: angiographic and pathologic outcomes

PURPOSE: This study aimed to compare the safety and efficacy of two resorbable microparticles in a porcine kidney model, focusing on recanalization and tissue injury outcomes over a 7-day follow-up period. METHODS: ). Approximately 5-10 mL of microparticle suspension was injected per kidney; the mean embolization time per kidney was 30 ± 5 minutes. RESULTS: At 2 hours post-embolization, complete recanalization was observed in all Nexsphere-F kidneys and in 9 of 10 KIPZA kidneys; 1 KIPZA kidney showed partial recanalization. Full recanalization was observed in all kidneys by day 7. Histopathologic evaluation (5 kidneys per group) revealed no residual emboli or parenchymal infarction in Group A. In Group B, minimal microparticle residue and focal infarction (mean infarcted area 2.78% ± 1.33%) were observed, along with endothelial proliferation in arcuate and interlobular arteries. CONCLUSION: In this exploratory pilot study, embolization with both Nexsphere-F and KIPZA microparticles resulted in early recanalization and minimal tissue injury. These proof-of-concept findings suggest that both microparticles may be suitable for temporary embolization when organ preservation is paramount, although larger powered studies with disease models and longer follow-up are needed. CLINICAL SIGNIFICANCE: These preliminary data support the potential of resorbable microparticles for temporary embolization, emphasizing their use in scenarios requiring parenchymal preservation and underscoring the need for further research.