833 - EMBOKARE
This report from Endovascular Today,April 2018, reviewed the available results of a clinical study based upon the pioneering work of Yuji Okuno from 2015 in the treatment of severe chronic osteoarthritis knee pain. Geniculate artery embolization (injection of tiny particles into the major artery supplying the knee structures) led to a statistically significant reduction in both the Visual Analog Scale (VAS) for pain assessment and the WOMAC osteoarthritis index indicating significant reduction in knee pain and stiffness.
This article in Endovascular Today, from April,2018, reviews the experiences of multiple interventional radiologists in their use of transcatheter embolization (the process of therapeutically blocking-off blood vessels by injecting a variety of materials through a small tube placed in the target blood vessel) to treat pelvic congestion syndrome (PCS). This condition that occurs in 10-15% of women is caused by incompetence of valves in the gonadal veins (usually on the left side) and occasionally in the internal iliac veins of the pelvis. This valvular incompetence allows back-flow of blood in the gonadal veins leading to the formation of distended pelvic varicose veins that in turn cause chronic pelvic pain as well as pain associated with sexual intercourse and sometimes external vaginal and thigh varicose veins. Transvaginal ultrasonography can be used as a screening study as well as MR and CT venography, although transcatheter contrast venography is highly accurate and can be performed at the time of embolization. One of the interventionalists prefers to first embolize (usually with metallic coils) only the left gonadal vein whereas another more aggressively treats both right and left gonadal veins as well as the internal iliac veins if dilatation is found in any of these veins in addition to the left gonadal vein. Uncommonly, PCS can be associated with left iliac vein compression (by the left common iliac artery, A.K.A.May-Thurner Syndrome), or left renal vein compression (between the abdominal aorta and superior mesenteric artery, the so-called Nutcracker Syndrome). In these situations, treatment of the PCS may include venous stenting (the intravenous placement of an expandable metal mesh work tube that counteracts the external compression of the vein).
This article, co-written by Japanese joint pain embolization pioneer Yuji Okuno, examines which patients would be the best candidates for geniculate artery embolization for osteoarthritis knee pain. Osteoarthritis (OA) is the most common form of arthritis that has been increasing primarily due to the increasing age of the population and rising rates of obesity. The knee is the most commonly affected joint. Many patients are unresponsive to medical therapy, and 15% of patients have debilitating knee pain after joint replacement surgery. Patients with long-standing knee pain resistant to conventional therapies, such as oral non steroidal anti-inflammatory drugs, oral opioid agents, physical therapy, muscle strengthening, intra-articular injection of hyaluronic acid, for at least 3 months are reasonable candidates for knee joint embolization. Spontaneous pain, including night time and rest pain, supports the presence of an abnormal abundance of blood vessels at the site of pain. Local tenderness during physical examination at the synovium and periosteum around the medial/lateral condyle,the infrapatellar fat pad, the medial/lateral meniscus base, and the medial/lateral side of the joint capsule also suggest the presence of abnormally abundant joint blood vessels. Contrast-enhanced MRI may be used to detect abnormal hypervascularity within the knee joint. Embolization is conducted through a tiny skin puncture, frequently in the groin, using I.V. sedation and local lidocaine anesthesia. A microcatheter (diameter < 1 mm) is guided into the medial geniculate artery supplying hyper vascular areas of the affected knee joint, and these tiny overly-abundant blood vessels are blocked off by injecting tiny particles through the microcatheter until the joint vascularity is significantly reduced. Following embolization of the knee joint, patients are sent home the same day and are instructed to refrain from vigorous physical activity for two weeks. They may continue on their conservative drug regimen.
