A minimally invasive procedure for chronic knee pain is helping some patients find significant relief without undergoing major surgery.
For Cynthia Schraf-Fletcher, 74, the results were “remarkably” successful.
Nearly a year after receiving a genicular artery embolization (GAE) in his right knee, Schraf-Fletcher says the improvement is comparable to the total knee replacement he previously underwent in his 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, he says, everyday activities like gardening and riding a stationary bike are much more enjoyable because of reduced pain.
How Genicular Artery Embolization Works
GAE is an outpatient procedure designed to relieve chronic knee pain by reducing blood flow to inflamed areas within the joint. By targeting abnormal blood vessels associated with inflammation, treatment can help decrease swelling and discomfort.
“To treat osteoarthritis in the knees, we often think about medications, physical therapy, maybe a steroid injection, and then, at the other end of the spectrum, a total knee replacement. There really hasn’t been anything for patients in between,” says Casadaban, a vascular interventional radiologist. “GAE is a promising minimally invasive procedure that can fill that gap for people who have failed conservative treatments but are not yet ready to undergo 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 long-lasting.
“We find that about 70% of patients get phenomenal results. They reduce their pain scores by half, sometimes more. We have some patients who don’t feel any pain after the procedure,” says Casadaban. “Patients who have tried many other treatments and have not received pain relief are happy to return to their normal activities.”
After experiencing complications from knee replacement surgery, Schraf-Fletcher was eager to explore another option. Looking back, he says choosing GAE was the right decision.
What happens during the procedure?
GAE usually lasts 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 images and contrast dye as a guide, doctors advance a small catheter through the femoral artery until it reaches the genicular arteries around the knee.
Once in position, the equipment releases microscopic beads that block blood flow to abnormal vessels located in painful areas identified by the patient.
Patients are monitored for several hours afterwards and are usually able to return home the same day. Doctors generally recommend taking it easy for a few days during recovery.
Originally developed in Japan a little over a decade ago, GAE has been gaining attention around the world. 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
Initial and ongoing research continues to produce encouraging results.
“The theory is that GAE reduces inflammation within the knee joint and symptom relief can last for years,” Casadaban says. “Four years of data published in Japan show that if you do an outpatient procedure, the pain relief can last for four years. In the U.S., we now have two years of data, which shows that if you have a good response, the pain relief can last for two years. That really speaks to the theory that we are hopefully changing 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 can 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 doctors are beginning to explore its use for other painful musculoskeletal disorders, such as frozen shoulder, tennis elbow, and plantar fasciitis.