Laboratory investigation: Resorbable microsphere for transient uterine artery occlusion

Researchers from France have recently developed a new kind of embolic, one that aims to ensure full and constant recanalization of the embolized artery. The most widely used embolics at this time degrade over several months, inciting chronic changes in the embolized vessel and organ. Previous animal models have shown that even after partial recanalization of the uterine artery, both fertility and birthweight are lowered. Remodeling of vessel walls can inhibit important dilatation of the uterine artery that occurs during pregnancy. A resorbable microsphere would occlude the vessel for a short time and achieve ischemia of a fibroid, but would subsequently be completely eliminated before the onset of a chronic response.

To show this, the authors embolized the uterine arteries of sheep using either their newly designed resorbable microspheres comprised of trisacryl-gelatin or traditional nonresorbable microspheres. At 7 days after embolization, an angiogram was performed to evaluate vascularity and the sheep were sacrificed to allow histologic evaluation of their arteries and uteri.

The study found that the resorbable microspheres disappeared and the arteries recanalized within 7 days in all of the sheep, something that was observed in only half of uterine arteries embolized with nonresorbable microspheres. Changes to the uterine tissue were observed to be similar. This exciting technology is yet to be tested in a large cohort, in a fibroid uterus, or in a human.


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Example of full UA recanalization and complete parenchyma opacification after embolization with REM. (a) Angiogram obtained before embolization. UA (arrow) and parenchyma (star) are opacified. (b) Angiogram obtained 10 minutes after embolization. Flow is interrupted at the level of the descending UA (arrow). (c) Angiogram obtained 7 days after embolization. Opacification of UA and its branches (arrow) at arterial phase. (d) Angiogram obtained 7 days after embolization. Opacification of parenchyma (star).


Citation:  Verret, V. et al. A Novel Resorbable Embolization Microsphere for Transient Uterine Artery Occlusion: A Comparative Study with Trisacryl-Gelatin Microspheres in the Sheep Model. Journal of Vascular and Interventional Radiology (2014)


Post author: Amish Patel, MD