For Cynthia Schraf-Fletcher, 74, the results were "remarkably" successful.

Nearly a year after receiving genicular artery embolization (GAE) on her right knee, Schraf-Fletcher says the improvement is comparable to the total knee replacement she previously underwent on her left knee.

"I couldn't be more pleased," says Schraf-Fletcher, who had the procedure performed by Leigh Casadaban, MD, MS, assistant professor of radiology at the University of Colorado Anschutz School of Medicine.

Today, she says everyday activities such as gardening and riding a stationary bicycle are far more enjoyable because of the reduction in pain.

How Genicular Artery Embolization Works

GAE is an outpatient procedure designed to ease chronic knee pain by reducing blood flow to inflamed areas within the joint. By targeting abnormal blood vessels associated with inflammation, the treatment can help decrease swelling and discomfort.

"For treating osteoarthritis in the knees, we often think of medications, physical therapy, maybe a steroid injection, and then on the far end of the spectrum is a total knee replacement. There really hasn't been anything for patients in between," Casadaban, a vascular interventional radiologist, says. "GAE is a promising minimally invasive procedure that may fill that spot for people who have failed conservative treatments but are not yet ready to have a major surgery."

According to Casadaban, people with mild to moderate osteoarthritis tend to benefit the most. Patients with more advanced disease can also undergo the procedure, although the effects are generally less durable.

"We find about 70% of patients have phenomenal results. They cut their pain scores in half, sometimes more. We have a few patients with no pain at all after the procedure," Casadaban says. "Patients that have tried a lot of other treatments and haven't had pain relief are happy to get back to their normal activities."

After experiencing complications from knee replacement surgery, Schraf-Fletcher was eager to explore another option. Looking back, she says choosing GAE was the right decision.

What Happens During the Procedure?

GAE typically takes between one and two hours and is performed under conscious sedation.

During the procedure, an interventional radiology team makes a small incision near the crease of the leg. Using X-ray imaging and contrast dye for guidance, doctors advance a tiny catheter through the femoral artery until it reaches the genicular arteries around the knee.

Once in position, the team releases microscopic beads that block blood flow to the abnormal vessels located in the painful areas identified by the patient.

Patients are monitored for several hours afterward and are usually able to return home the same day. Doctors generally advise taking it easy for a few days during recovery.

Originally developed in Japan a little more than a decade ago, GAE has steadily gained attention worldwide. Since 2021, the FDA has granted "breakthrough device status" to multiple devices related to the procedure in the United States.

Research Suggests Long Lasting Pain Relief

Early and ongoing research continues to produce encouraging results.

"The theory is that GAE reduces inflammation inside the knee joint, and symptom relief can last years," Casadaban says. "Four-year data published in Japan shows that if you have one outpatient procedure, your pain relief can last for those four years. In the U.S., we now have two-year data, which shows that if you have a good response, pain relief can last two years. That really speaks to the theory that we're hopefully modifying something in the joint."

Casadaban is currently leading two clinical trials at CU Anschutz. One study is examining changes in knee fluid among patients receiving GAE. The other is evaluating a temporary arterial treatment device called Nexsphere-F, which blocks small blood vessels in the knee that may contribute to inflammation and pain.

Expanding Beyond Knee Osteoarthritis

Osteoarthritis is a degenerative joint disease that affects millions of people each year and can occur in many different joints throughout the body.

Although GAE is currently used only for knee conditions, Casadaban says researchers and physicians are beginning to explore its use for other painful musculoskeletal disorders, including frozen shoulder, tennis elbow, and plantar fasciitis.