Preclinical Evaluation of a Zotarolimus-Eluting Stent for Intracranial Application: A 30-Day Procedural Feasibility and Clinical Observation Canine Study.

BACKGROUND AND PURPOSE: Zotarolimus-eluting stents (ZES) are increasingly used off-label for intracranial atherosclerotic disease (ICAD), yet foundational preclinical data evaluating procedural delivery and short-term vascular safety in cerebral anatomy is sparse. We evaluated the procedural feasibility and 30-day clinical safety of the Onyx Frontier ZES in a canine intracranial model. METHODS: In a prospective study, 12 healthy canines on dual antiplatelet therapy underwent basilar artery implantation of a 2.0 × 8.0 mm Onyx Frontier ZES. Vertebral artery tortuosity was angiographically graded as Type I (mild), II (moderate), or III (severe). Endpoints focused on procedural success and 30-day clinical safety, monitored via angiography, serial neurological examinations, and clinical pathology. RESULTS: Technical success was 100% (12/12) despite challenging anatomy (mean basilar artery diameter: 1.39 mm). Tortuosity distribution was 33.3% Type I, 58.3% Type II, and 8.3% Type III. Post-deployment angiographic narrowing consistent with transient vasospasm was observed in 7/12 animals, without flow limitation; with only one requiring intra-arterial verapamil for resolution. One instance (8.3%) of self-limiting contrast extravasation occurred at the distal basilar artery without long-term sequelae. At 30 days, there was 0% mortality and no procedure-related neurological adverse events. Serial clinical pathology panels demonstrated an absence of systemic organ toxicity or sustained systemic inflammation. CONCLUSION: Implantation of the Onyx Frontier ZES is highly feasible in sub-2 mm, tortuous intracranial vessels. The platform demonstrated an excellent 30-day clinical safety profile, providing essential procedural and early clinical data to support future integrated regulatory evaluations for ICAD.