A novel, endovascular flow-restoration therapy was recently discussed at the 2025 European Society of Minimally Invasive Neurological Therapy. Petra Cimflová (University Hospital of Bern, Bern, Switzerland) gave a presentation detailing the results of the Re-CHILL study, which retrospectively reviewed symptomatic intradural chronic total occlusions (CTO’s) of the internal carotid, middle cerebral, vertebral or basilar arteries.

The goal was to review the viability and outcomes of endovascular therapy in these cases, though only a handful of hospitals have attempted this procedure to date. Intradural application is complicated for several reasons, including increased likelihood of distal embolism and the tendency of deformed arterial plaques to obstruct perforators. In her presentation, Cimflová described the study in detail, with n=25 cases from half a dozen hospitals. Median age was 65 years with nearly ¾ of the cases having history of stroke or transient ischemic attack.

Early outcomes were promising. Of the 25 patients, 17 improved clinically, 5 remained unchanged, and 3 worsened within the first 10 days. The Re-Chill study is ongoing, collecting more data for further use.

Transonic knows that endovascular and open surgery will continue to be essential partners for many years to come. We applaud the researchers on their current progress, and eagerly await the conclusion of the study.