When is genicular artery embolization (GAE) appropriate?

From the Guidelines

Genicular artery embolization (GAE) is appropriate for patients with severe knee osteoarthritis who have failed conservative treatments and have confirmed synovial inflammation or hypervascularity on imaging studies. This minimally invasive procedure is particularly suitable for patients experiencing persistent knee pain despite medications, physical therapy, and injections. The goal of GAE is to block small blood vessels that feed inflamed synovium, reducing inflammation and associated pain.

Key Considerations

• Candidates for GAE should have moderate to severe knee osteoarthritis and should not be candidates for or wish to delay knee replacement surgery 1.
• GAE is typically performed under moderate sedation as an outpatient procedure, using microparticles to embolize the abnormal vessels while preserving normal circulation.
• Patients can expect gradual pain improvement over 1-4 weeks following the procedure, with benefits potentially lasting 1-2 years or longer.
• GAE is contraindicated in patients with active infection, severe renal insufficiency, contrast allergy, or certain vascular conditions.

Evidence-Based Recommendations

• The American College of Radiology recommends that transcatheter arteriography/embolization is usually appropriate as the next intervention for a patient with ongoing or recurrent lower GIB where appropriate colonoscopy has localized the bleeding site and treatment was attempted 1.
• However, in the absence of active extravasation at angiography, embolization should not be performed, as the exact site of bleeding is not identified 1.
• The choice of embolic agent, such as microcoils or liquid adhesive agents like N-Butyl cyanoacrylate (NBCA), depends on the patient's underlying coagulopathy and the operator's expertise 1.

Potential Complications

• While generally safe, potential complications of GAE include skin discoloration, transient skin numbness, and rare cases of non-target embolization.
• Major ischemic complications are uncommon, usually occurring at a rate of 3% or lower 1.

From the Research

Indications for Genicular Artery Embolization (GAE)

• GAE is appropriate for patients with knee osteoarthritis (OA) who have severe chronic pain refractory to conservative treatment and moderate-to-severe knee OA 2.
• The procedure is suitable for patients with mild-to-severe knee osteoarthritis who have failed conservative treatment for more than 6 months 3.
• GAE can be considered for patients with symptomatic knee OA who have not responded to other conservative therapies 4.

Patient Selection Criteria

• Patients with moderate or severe knee OA (Kellgren-Lawrence grade 2,3, or 4) who have previously failed conservative therapy are potential candidates for GAE 4.
• Patients with higher baseline knee pain severity may be more responsive to GAE 5.

Safety and Efficacy

• GAE has been shown to be a safe procedure with minimal complications, including transient skin discoloration and mild knee pain after the procedure 5, 3, 4.
• The procedure has been demonstrated to be effective in reducing pain symptoms and improving function in patients with knee OA, with significant decreases in visual analog scale (VAS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores 5, 3, 4.