Uterine artery embolization in a sheep model: biodegradable versus non-degradable microspheres

Background: Transarterial embolization with particles is a relatively common treatment method in both malignant and benign disorders. Permanent occlusion of the uterine arteries may sometimes be disadvantageous. Purpose: To compare the local tissue effects, possible side effects, and extent of recanalization following uterine artery embolization, using either degradable or non-degradable microspheres in a sheep model. Material and Methods: In 22 female sheep, the uterine artery (UA) was unilaterally, superselectively embolized, with either degradable starch microspheres-DSM (group A) or calibrated gelatin coated spherical shape tris-acryl microspheres-TGMS (group B). The completion of embolization was confirmed by angiography. The animals were kept in the animal research facilities for 14 days and sacrificed following new angiographic evaluation. Gross and histological examination of the uterus and other organs was performed. Results: The procedure was successful in all animals. At final angiographic evaluation recanalization was found in 82% of the ewes in group A and in 18% in group B. At histopathological examination, tissue impairment was similar in both groups, whereas vascular changes were more pronounced in the TGMS-group. Conclusion: Embolization with DSM was associated with significantly higher degree of recanalization, than after embolization with TGMS.