Repeated Genicular Artery Embolization Using Permanent Microspheres for Severe Osteoarthritis and Postsurgical Pain

PURPOSE: To investigate reperfusion after genicular artery embolization (GAE) in patients with severe osteoarthritis (OA) or persistent pain after total knee replacement (post-TKR), who did not achieve clinical improvement after initial GAE, and to evaluate the clinical efficacy of repeat GAE (reGAE). MATERIALS AND METHODS: This prospective observational study included patients with radiographically severe OA or post-TKR pain. GAE was performed using permanent microspheres. Clinical outcome was assessed at 6 weeks, 3, 6, 9, and 12 months using the numeric rating scale (NRS). Minimal clinically important difference (MCID) was defined as an improvement of at least 2 points compared with baseline. Patients failing to achieve MCID at 6 months underwent reGAE. Angiographic blush size before and after embolization during GAE and reGAE was measured and compared. RESULTS: In 55 patients (87 GAEs), a median of 4 (range, 2-6) vessels was treated, with a median total embolic volume of 4.5 mL (1.5-10.1 mL). After initial GAE, 23 patients (42%) achieved MCID. Following reGAE at 6 months, an additional 20 patients (36%) reached MCID, with sustained efficacy up to 6 months after reGAE (p ≤ 0.0001); 12 patients (22%) remained non-responders. Quantitative angiographic analysis demonstrated a significant increase in blush size within previously treated vessels, necessitating reGAE (p ≤ 0.0001). CONCLUSION: After GAE using permanent microspheres, reperfusion of previously treated vessels was observed at 6 months in all patients failing to achieve MCID. ReGAE increased the proportion of clinical responders, supporting its role as an effective additive treatment strategy in severe OA and post-TKR pain.