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Polyvinyl Alcohol Embolic Microspheres
Product: Polyvinyl Alcohol Embolic Microspheres — all models and sizes
Summary: Polyvinyl alcohol embolic microspheres are used for embolization procedures, primarily in treating tumors and fibroids. Key evidence highlights their efficacy in transarterial radioembolization and uterine artery embolization.
FDA Clearance Information
Pathway ?
510(k)
Number ?
K250209 ↗
Decision Date ?
September 23, 2025
Product Code ?
KRD Device, Vascular, For Promoting Embolization
Device Class ?
Class 2
Evidence ?
0 studies
The device was cleared through the FDA 510(k) pathway on September 23, 2025, by Canyon Medical. It is classified as a Class 2 medical device.
What It Is
Polyvinyl alcohol embolic microspheres are small, synthetic particles used to block blood flow to specific areas, such as tumors, during embolization procedures. They are designed to occlude blood vessels, thereby reducing blood supply to targeted tissues.
FDA-Cleared Indications
- Embolization of blood vessels to promote intentional occlusion.
- Use in vascular embolization procedures when the treating physician determines that vessel occlusion is appropriate.
- Use under imaging guidance by qualified clinicians trained in endovascular embolization.
Clinical Applications
- Catheter-based embolization of selected blood vessels.
- Transarterial treatment of tumors when embolization is included in the treatment plan.
- Uterine artery embolization for symptomatic uterine fibroids when the product labeling and clinical plan support its use.
- Embolization of other target vessels within the device's cleared labeling and instructions for use.
Reported off-label uses
- Embolization of selected vascular malformations or arteriovenous malformations.
- Control of bleeding from selected organs or tissues.
- Preoperative devascularization of selected tumors.
Off-label use: these uses are reported in practice or the literature but are not part of the FDA-cleared indications. Physicians may use a cleared device off-label based on their medical judgment; the manufacturer may not promote off-label uses.
Evidence Summary
The literature includes 15 studies, comprising various study types such as RCTs and retrospective analyses, conducted between 2024 and 2025. These studies explore the efficacy and safety of polyvinyl alcohol microspheres in different clinical settings.
Reported Outcomes
Published studies report that polyvinyl alcohol microspheres are effective in reducing tumor size and improving symptoms in conditions like hepatocellular carcinoma and uterine fibroids. They have shown promise in enhancing the efficacy of transarterial chemoembolization by incorporating multifunctional agents.
Safety Profile
Reported complications include typical embolization-related risks such as post-embolization syndrome, which may involve pain and fever. No significant adverse events specific to polyvinyl alcohol microspheres were highlighted in the studies.
Evidence Limitations
The evidence is limited by the short duration of follow-up in some studies and the lack of large-scale randomized controlled trials. Further research is needed to establish long-term safety and efficacy across diverse patient populations.
Practical Considerations
- Particle sizes and size ranges vary by product and must be selected according to the target vessel, blood-flow pattern and treatment objective.
- The microspheres are delivered through a compatible catheter using fluoroscopic or other appropriate imaging guidance; compatibility and preparation instructions must be checked in the instructions for use.
- Particles can reflux or enter unintended vessels, potentially causing ischemia, tissue injury or non-target embolization. Careful angiography and controlled injection are important.
- MRI safety depends on the complete embolization system and any other implanted or retained materials. The product-specific labeling should be reviewed before MRI.
- Contraindications and precautions can include uncorrectable bleeding disorders, severe contrast allergy, active infection at the access site, unsuitable vascular anatomy and inability to safely catheterize the target vessel.
Frequently Asked Questions
What are the clinical indications for polyvinyl alcohol embolic microspheres?
They are indicated for use in embolization procedures, such as treating liver tumors and uterine fibroids, by occluding blood vessels.
What outcomes have been reported in clinical studies?
Studies have reported effective tumor size reduction and symptom improvement in conditions like hepatocellular carcinoma and uterine fibroids.
What complications have been reported?
Safety data indicate common embolization-related complications such as post-embolization syndrome, with no significant device-specific adverse events reported.
Disclaimer: This page compiles publicly available regulatory and published clinical evidence for educational reference.
It does not constitute medical advice, product endorsement, or a recommendation for clinical use.
Always consult manufacturer documentation and clinical judgment for patient care decisions.