Innovation
South Africa’s first genicular artery embolisation (GAE) took place in February this year at Mediclinic Constantiaberg.
The minimally invasive procedure works in a knee damaged by osteoarthritis, cutting off the blood supply to the inflamed areas, eliminating pain and slowing down the process of cartilage degradation.
Understanding interventional radiology
Dr Dale Creamer, the interventional radiologist who performed the ground-breaking GAE procedure at Mediclinic Constantiaberg, explains that interventional radiology uses precise, image-guided techniques to perform minimally invasive procedures for the diagnosis and treatment of conditions across multiple organ systems. “This results in shorter hospital stays and is seen as an alternative to major surgery,” he says.
The field of interventional radiology is considered a sub-specialty in more developed healthcare systems, Dr Creamer adds. Having trained in the area at the University of Calgary in Canada, he gained experience in Europe before returning to South Africa to found Cape Town Interventional Radiology, South Africa's only sub-specialised interventional radiology practice.
The GAE procedure explained
Internationally, the GAE procedure has been performed for over a decade. It was pioneered by Japanese interventional radiologist Yuji Okuno, who proposed the novel idea that inflammation could be treated by blocking blood supply to affected areas.
It’s important to understand that this is not a procedure patients can self-select. Only an orthopaedic specialist can assess whether GAE is appropriate for your specific condition and, if so, provide the necessary referral. It forms part of a broader, multidisciplinary treatment plan and should only be considered under specialist guidance.
In the case of knees affected by osteoarthritis, as the cartilage around the joint degrades, the body recognises the damage, Dr Creamer explains. “In its attempt to heal it, the body provides a new blood supply to that joint, a process known as neovascularity.” However, this is counterproductive.
“You’d think that sending more blood supply to the knee joint would help, but instead it drives the inflammation, creating a painful inflammatory cascade,” he continues. “It also causes further degradation of the cartilage. So, by blocking off this new blood supply, you can stop the pain and slow down the process of cartilage degradation.”
The GAE procedure has been applied to multiple areas, including the shoulder and hip, but its use in the knee has generated the most research and positive results.
Minimally invasive, GAE requires considerable skill. The patient is placed under conscious sedation and feels no pain during the procedure, which is performed using image guidance. Through a catheter inserted via the groin, doctors deliver resorbable microscopic particles called Nexsphere to the knee. These gelatin-based particles, designed to plug small blood vessels, are considered the gold standard in musculoskeletal embolisation.
“We use a micro catheter to find the abnormal genicular arteries – a network of small blood vessels that supply blood to the knee joint – and then we embolise them (block the vessels),” says Dr Creamer. As GAE selectively blocks the abnormal, inflamed blood vessels in the lining of the knee, the procedure is highly intricate. Recovery usually takes 6-12 weeks and includes measures such as icing and elevating the knee, as well as physiotherapy to support healing and restore function.
Who is a candidate for GAE?
Dr Creamer emphasises that GAE is not a substitute for a knee replacement, as it blocks abnormal blood supply but does not reverse the underlying osteoarthritis, meaning symptoms may eventually return. However, it can delay the need for surgery – a significant benefit, as studies show that having a knee replacement at a younger age is linked to higher complication rates and a greater likelihood of revision surgery later in life. One GAE procedure can push out a knee replacement by up to three years and it can also be repeated, he explains.
“Until now, the only treatments available were either injections, chronic pain medication, or physio,” he adds. “The next step was knee replacement. There wasn’t an in between. The GAE fits into that space where treatment is not working, and where patients are too young for knee replacement and want to postpone this procedure.”
Mediclinic Constantiaberg’s world-class facility
Following contact from the first patient in South Africa to undergo the procedure, Dr Creamer consulted with a colleague and arthroplasty surgeon, who felt she would benefit from GAE. She had not yet reached stage four osteoarthritis – the most severe form, characterised by bone-on-bone contact. This meant she still had some remaining cartilage. Being highly motivated to delay knee replacement, she was considered a suitable candidate for the procedure.
“We decided to do the procedure at Mediclinic Constantiaberg, because the catheterisation laboratory (cath lab) there is cutting edge,” he says. “It’s well equipped to manage these cases, both within our practice and within the field of interventional radiology in South Africa. “Mediclinic Constantiaberg was also a preferred hospital for her medical aid. While interventional radiology in South Africa is still about 20 years behind the rest of the world, Dr Creamer says it’s advancing rapidly. “People are now able to understand more about interventional radiology, and this kind of exposure will only grow and drive the speciality.”