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.