What are RWD MCAO Sutures?

RWD MCAO sutures are silicone-coated nylon monofilaments engineered for the intraluminal filament middle cerebral artery occlusion (MCAO) model — the most widely used technique for inducing reproducible focal cerebral ischemia in mice and rats. Refined through tens of thousands of experiments, the design balances the softness needed to navigate the carotid bifurcation with the rigidity required to advance from the external carotid artery, through the internal carotid, and into the middle cerebral artery branch without piercing the vessel wall or deflecting off-course.

The result is a consistent occlusion that produces reproducible infarct volumes — critical for stroke models where inter-animal variability has historically been one of the largest sources of experimental noise. Each suture is precision-molded from a proprietary silicone formulation and matched to a specific animal weight range, with 20 variants covering mice from 15 g through rats above 400 g.

Key Features

• Proprietary Silicone Formulation: Custom silicone compound improves suture durability and reuse probability, reducing per-experiment cost while maintaining occlusion performance across multiple model attempts.
• Nylon Core for Surgical Flexibility: The nylon thread base provides the flexibility needed to follow the natural curve of the carotid system — a key contributor to higher success rates compared to stiffer alternatives.
• Open-Molded Manufacturing: Unique open-mold technique produces uniform coating height across the production batch, eliminating the suture-to-suture variability that disrupts model reproducibility.
• Cylindrical Silicone Head: Cylinder-shaped occlusion head ensures immediate blood flow cessation upon arrival at the MCA bifurcation — critical for time-sensitive ischemia/reperfusion protocols.
• 20 Size Variants: Coating diameter from 0.17 mm (mouse, 15–20 g) up to 0.45 mm (large rats, >400 g), with tip diameters from 0.07 to 0.20 mm — matched to animal weight for optimal occlusion.
• Bulk Pack Format: 50 sutures per package across all variants, sized for typical preclinical study cohorts.

Typical Workflow

The intraluminal filament MCAO model proceeds as follows: animal is anesthetized; the common carotid, external carotid, and internal carotid arteries are exposed; the suture is inserted through the external carotid stump and advanced into the internal carotid until resistance signals the MCA branch; ischemia is timed (typically 30–120 minutes); the suture is withdrawn to allow reperfusion. Successful occlusion is commonly verified intraoperatively with laser speckle imaging or laser Doppler flowmetry, and infarct volume is quantified post-mortem via TTC staining.