Chinmaya Shelgikar, MD, discusses the benefits of vascular surgeons performing geniculate artery embolization.
Geniculate artery embolization (GAE) is an intra-arterial, catheter-based procedure used to treat chronic knee pain that is caused by osteoarthritis (OA). It targets the distal branches of the geniculate arteries supplying the synovium and joint capsule of the knee and then occluding the distal vessels.
A salient pathological feature of knee OA is low-grade chronic inflammation, often accompanied by abnormal angiogenesis in the synovium and adjacent structures. It is hypothesized that these new, fragile blood vessels play a role in pain generation by carrying inflammatory mediators and sensitizing nearby nerves.
The technique of GAE is relatively straightforward. It can either be done through an antegrade or retrograde common femoral access using a 5F sheath. Often, the genicular vessels can be selected with a 4F catheter. This is usually followed by a micro catheter into the distal branches and then selective embolization using 100-to-300-micron embospheres. Typically, three-to-four vessels are selected to be embolized. To avoid non-target embolization, it is essential to do a thorough diagnostic angiogram to make sure that the geniculate vessels do not collateralize to the popliteal artery or the recurrent anterior tibial artery.
The procedure typically takes 1 to 2 hours and is performed under conscious sedation in an office-based lab (OBL) or hospital outpatient setting. Most patients can return home the same day and resume normal activities within a few days. GAE does not alter the structural integrity of the knee, making it an appealing option for patients who are not candidates for surgery or wish to delay knee replacement. Long-term clinical studies are still ongoing; however, one-year data appear promising.
Patient selection for GAE is crucial. They should be fully worked up by orthopedic surgery or physical medicine and rehabilitation (PM&R) specialists. Direct patient referrals should be avoided. There are several benefits for vascular surgeons to learn this procedure. From a technical perspective, it is good practice for keeping up with micro catheter skills and embolization techniques. These skills can be then extrapolated to other vascular bodies, including the prostate, liver and for treatment of arteriovenous malformations.
It is also an important way to collaborate with specialties that we don’t normally share patients with and would facilitate a symbiotic relationship with our orthopedic surgery colleagues. Commonly, we only know them when a vascular complication occurs in one of their patients. Additionally, a tighter working relationship with PM&R may help increase peripheral arterial disease (PAD) volumes as well. Finally, in the era of decreasing reimbursement for PAD work, this can be an important way to financially supplement a vascular practice; especially those working in an OBL.
In general, the patients best suited for this procedure are those who have moderate-to-severe osteoarthritis who have failed conservative treatments such as physical therapy, NSAIDs, intra-articular corticosteroids, geniculate nerve ablation or hyaluronic acid injections. It is not recommended for patients with advanced joint destruction, extensive bone-on-bone changes, or those with active infections or coagulopathies. The procedure is fully covered for Medicare recipients under the CPT code 37242. Private payers often require a prior authorization but denials are less common given the cost of knee replacement surgery.
Potential risks of this procedure—including embolization and access-site injuries—are rare. Most commonly, patients will have post-embolization syndrome, including skin discoloration, knee swelling, and more pronounced knee pain for the first few weeks. This improves significantly and most patients at one-month follow-up do not have any significant symptoms.
Chinmaya Shelgikar is vascular surgeon with Trinity Health IHA Medical Group in Ann Arbor, Michigan.
