Arissa Medical has announced that it has completed enrolment in a pilot study evaluating the safety and efficacy of the company’s Syntra device for the intrasaccular treatment of irregular, acutely angulated, wide-necked sidewall and wide-necked bifurcation intracranial aneurysms.
The pilot study was conducted by interventional neuroradiology (INR) principal investigator Juan Gabriel Sordo at Instituto de Neurocirugía Dr Alfonso Asenjo in Santiago, Chile. Six-month digital subtraction angiography (DSA) follow-up has been completed for the majority of enrolled patients, an Arissa press release notes.
According to Sordo, the Syntra device successfully enabled the treatment of “difficult” wide-necked aneurysms and prevented the subsequent herniation of coils into the parent artery—addressing what he described as “a major issue” in challenging aneurysms presenting with an acutely angulated morphology.
Luis Augusto Lemme (Buenos Aires, Argentina) and Gary Duckwiler (University of California Los Angeles [UCLA], Los Angeles, USA), medical advisors to Arissa, further noted that Syntra’s ability to adjust and conform to irregular aneurysm morphologies was observed during the pilot feasibility study. The device’s deliverability and adaptive nature enable a workflow that remains familiar to neurointerventional teams, and can be easily integrated into standard coiling practices, they added.
As of the time of this announcement on 22 December 2025, no serious adverse events and no device-related adverse events have been reported in patients enrolled in the pilot study. All treated patients remain alive and clinically well, Arissa also claims, going on to state that current findings show “strong aneurysm occlusion results” by the six-month follow-up. With this enrolment complete, the company will continue scheduled angiographic follow-up—including six- and 12-month DSA—and plans to present complete findings once the study concludes.
The Syntra device is a novel adjunctive ‘framing’ 3D scaffold endoskeleton designed to enhance intrasaccular neck coverage in the treatment of wide-necked intracranial aneurysms. By reducing the effective neck diameter, Syntra provides stable support for adjunctive coil embolisation to help achieve durable, flow-attenuated intrasaccular occlusion in irregular aneurysm morphologies.
Arissa reports that the added stability at the aneurysm neck enables operators to deploy ‘longer, high-packing volume XL-type soft 3D complex filling coils’, potentially improving packing density while minimising the total number of coils required per procedure—which may translate to reduced procedural complexity, lower radiation exposure and shorter procedure times, particularly in challenging wide-necked aneurysm cases.
