Comparison of Permanent and Resorbable Alginate Microspheres for Safety and Embolic Effects in a Porcine Renal Artery Embolization Model

Purpose This study evaluated porcine renal artery embolization using resorbable alginate microspheres versus permanent microspheres (Embozene), assessing vessel recanalization, local/systemic foreign body reactions, and potential complications. Materials and Methods Twelve Yorkshire swine (3 female, 9 male) underwent unilateral kidney arterial embolization with either Embozene or resorbable microspheres. Angiography was performed to confirm embolization. Vessel recanalization for was determined through angiography. The effect of embolization was evaluated by assessment of serum chemistry markers and by renal histopathology at 1, 3, 7 and 28 days post-procedure. Results Embolization procedures with both embolic agents were performed with 100% technical success. Hematology, coagulation factors and serum chemistry were largely unremarkable throughout the study period of 28 days. Alginate resorbable alginate microspheres facilitated compete recanalization and revascularisation within the initial 24hr observation window, while the permanent microsphere remained present at all evaluated time points. No inflammation was observed with resorbable microsphere whereas Embozene-induced inflammation was minimal to mild. Vascular histopathologic alteration with resorbable microspheres was limited and resolved by 24 hours, whereas Embozene caused sustained injury extending alteration to the internal elastic lamina, tunica media or adventitia. Conclusion Alginate resorbable microsphere demonstrated effective temporary embolization with a recanalization time of around 24 hours together with complete renal tissue recovery, no systemic impact, and minimal local reaction compared to Embozene. The findings suggest that embolization using resorbable microspheres is safe and may be suitable for use where temporary embolization of vessels is required.