Endovascular coil embolization with second-generation hydrogel coils could decrease the rate of unfavorable outcomes in patients with small- and medium-sized intracranial aneurysms, according to a new study published in Stroke.

“Endovascular embolization of intracranial aneurysms with hydrogel-coated coils lowers the risk of major recurrence, but technical limitations (coil stiffness and time restriction for placement) have prevented their wider clinical use,” wrote lead author Christian Taschner, MD, with the University Hospital Freiburg in Germany. “We aimed to assess the efficacy of softer, second-generation hydrogel coils.”

The researchers conducted a randomized controlled trial at 22 centers in France and Germany. Patients with untreated intracranial aneurysms within four to 12 mm in diameter were eligible for the study and were coiled with second-generation hydrogel coils or bare platinum coils. The researchers sought to examine outcomes including aneurysm recurrence, retreatment, morbidity that prevented angiographic controls and death during treatment and follow up.

Some 484 patients were used as the study cohort, of which 243 and 241 patients were coiled with hydrogel and bare platinum, respectively. Data for analysis was available for 456 patients.

Approximately 20 percent of patients in the hydrogel group and approximately 29 percent in the bare platinum group had an unfavorable outcome. The researchers noted there was a statistically significant reduction in the proportion of an unfavorable composite primary outcome with hydrogel coils.

“Our results suggest that endovascular coil embolization with second-generation hydrogel coils may reduce the rate of unfavorable outcome events, composed of major aneurysm recurrence, aneurysm retreatment, morbidity that prevented angiographic controls, and any death during treatment and follow-up in patients with small- and medium-sized intracranial aneurysms,” the authors concluded.