In Vitro Evaluation of Hydrogel Coils Combined with Liquid Embolic and Sclerosing Agents for Endovascular...

Hydrogel coils have expandable hydrogels that enhance the embolization effect. Hydrogel coils are sometimes used in combination with liquid embolic or sclerosing agents. This study evaluated the effect of liquid embolic and sclerosing agents on hydrogel coils.

This study consists of two experiments. (1) 0.035 inch-outward-expanding hydrogel coils were soaked in the following solutions: ethanol, 25% n-butyl-2-cyanoacrylate with lipiodol (NBCA), 5% ethanolamine oleate with iopamidol (EOI), and 3% polidocanol. Changes of the hydrogel coils were observed sequentially using a stereomicroscope. (2) Hydrogel coils were soaked in phosphate-buffered saline (pH 7.4, 37 °C) for > 30 min and then moved into the above solutions. Changes of the hydrogel coils were evaluated over time.

(1) The primary coil diameter soaked in ethanol and NBCA did not change. The primary coil diameter soaked in EOI and polidocanol increased to 2.7 times the original value and 3.1 times, respectively, but the hydrogels cracked. (2) The primary coil diameter of expanded coils soaked in phosphate-buffered saline was 2.0 times the original value. The primary coil diameter decreased 1.0-fold in ethanol. In NBCA, frayed structures gradually appeared at the surface of the hydrogels, increasing in primary coil diameter 4.3 times, and were exposed from NBCA. The primary coil diameter soaked in EOI and polidocanol increased 2.5 times and 2.8 times, respectively, and the hydrogels cracked.

In vitro, sclerosing agents disabled or damaged hydrogel coils. The combination of sclerosing agents and hydrogel coils might clinically have adverse effects, including the insufficient and non-target embolization.