Millipede Aspiration for Revascularization in Stroke (MARRS): prospective trial of a novel 0.088 inch corrugated catheter.

BACKGROUND

The Millipede AspiRation for Revascularization in Stroke (MARRS) pivotal study was a prospective, multicenter, single arm trial evaluating the safety and efficacy of the corrugated Millipede catheter system in patients with acute ischemic stroke due to large vessel occlusion.

METHODS

Patients aged 18-85 years with internal carotid artery, M1, M2, or basilar artery occlusions treatable within 8 hours were eligible. Catheter selection was based on target vessel diameter (Millipede88 >2.7 mm; Millipede70 >2.2 mm). The primary efficacy endpoint was modified Thrombolysis in Cerebral Infarction (mTICI) ≥2b within ≤3 passes without rescue therapy. Imaging and clinical outcomes were independently adjudicated. Secondary endpoints included first pass effect (mTICI ≥2c).

RESULTS

180 patients were treated (57% US, 43% EU). Median age was 69 years, mean baseline National Institutes of Health Stroke Scale score was 17, and median Alberta Stroke Program Early CT Score was 9. M1 occlusion was the most common target lesion (62%). The primary endpoint was achieved in 160/180 patients (88.9%; 95% CI lower bound 84.3%) in the intention-to-treat cohort. Direct first pass aspiration was performed with Millipede88 and Millipede70 in 64% and 36% of patients, respectively. Navigation success was 96% with Millipede88 and 99% with Millipede70. Among Millipede88 patients, first pass mTICI ≥2c was achieved in 60%, increasing to 75% in the M1 subgroup. Final mTICI ≥2c was achieved in 85% of primary Millipede88 cases. Symptomatic intracranial hemorrhage occurred in 2.3%, intracranial dissection in 1.1%, no perforations occurred, and 90 day all cause mortality was 13.9%.

CONCLUSIONS

The Millipede aspiration system demonstrated excellent deliverability and high rates of first pass and final mTICI ≥2c, particularly in M1 occlusions, with low rates of adverse events.

TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT05714501.