Medtronic's Onyx LES Receives FDA Approval for New Indication in Chronic Subdural Hematoma Treatment

Medtronic announced itsLiquid Embolic Agent---Onyx LESReceived FDA approval for use in middle meningeal artery (MMA) embolization as an adjunctive therapy to surgical treatment of symptomatic subacute or chronic subdural hematoma (SDH). This marks an important step forward in the treatment of chronic subdural hematoma.

Executive Evaluation

"This approval clearly represents a shift in the standard of care. For the first time in the U.S., we have a rigorously studied, evidence-based therapy that, when used in conjunction with surgery, effectively reduces the risk of recurrence and reoperation. Many patients are older adults who are more physically vulnerable, some of whom have long endured the cycle of surgery, recovery, recurrence, and reoperation. The expanded indication for Onyx LES provides a safer, longer-lasting solution to interrupt the underlying vascular pathological processes that lead to recurrence."

---Adam Arthur   Chief Medical Officer of Medtronic

"Data show that, compared with surgery alone, Onyx therapy can reduce the risk of recurrence or reoperation by two-thirds. This new indication transforms middle meningeal artery embolization from a promising technique into a clinically validated treatment tool, helping doctors and patients reduce the risk of recurrence, avoid repeat surgeries, and improve long-term outcomes."

---Linnea Burman  President of Medtronic Neurovascular

This FDA approvalOnyx LESThe new indications are primarily based on studies conducted by Medtronic.EMBOLISE Clinical Trial. This is aFor patients with symptomatic subacute and chronic subdural hematoma, a comparative study was conducted on "surgery combined withOnyx LESEfficacy of Middle Meningeal Artery Embolization versus Surgery Alone

The research findings were published in a journal last year.《The New England Journal of Medicine》above.Studies show that the combined treatment regimen can reduce the hematoma recurrence rate and reoperation rate by approximately 63%. Meanwhile, it also demonstrates a higher level of safety.No findings related to the postoperative period of 180 daysOnyx LESNo related adverse events, and no cause.Onyx LESOr death cases caused by middle meningeal artery embolization surgery.

Chronic Subdural Hematoma

Onyx LES

Onyx LESIt is a non-adhesive liquid embolic agent (LEA) based on ethylene-vinyl alcohol (EVOH) copolymer. Its main components are a mixture of ethylene-vinyl alcohol copolymer (EVOH), dimethyl sulfoxide (DMSO), and suspended micronized tantalum powder, where EVOH is the primary component, DMSO acts as the solvent, and the tantalum powder serves to enhance its visibility under X-rays.

Onyx LESProvides complete filling and distal penetration for peripheral lesions. It is delivered through a microcatheter under fluoroscopic guidance. The non-adhesive nature of the system allows for more distal lesion embolization without the risk of catheter retention. Additionally, higher viscosity enables controlled deployment.

Onyx LES has two formulations.

• Onyx 18 LES (6% EVOH, Viscosity 18cSt): Lower viscosity allows it to flow further and penetrate deeper into the target lesion;

• Onyx 34 LES (8% EVOH, Viscosity 34cSt): Higher viscosity provides greater control in higher blood flow and larger fistula components.

Onyx LES Polymer Properties

• Precipitation occurs upon contact with aqueous solutions (such as blood, water, contrast agents);

• Flowing like lava, solidifying from the outside in as the solvent diffuses;

• Delivered in a cohesive manner, forming a sponge-like, continuous embolus.