Introducing Advanced Simulation Training for GAE
‍

‍
Introduction to Genicular Artery Embolization

Genicular artery embolization (GAE) is a novel, minimally invasive technique designed to alleviate pain and improve function in patients suffering from knee osteoarthritis (OA) [1, 2]. By selectively embolizing pathological neovessels—new blood vessels that form in response to chronic inflammation—GAE aims to disrupt the inflammatory cycle and reduce associated pain [1, 2]. In recent years, interest in this treatment modality has grown exponentially, with many countries initiating both clinical applications and research projects on GAE [3, 4]. However, GAE is a complex procedure, and proper implementation is essential. This article serves as an initial exploration into the field of GAE and sets the stage for our upcoming hands-on preview of a dedicated simulation-based GAE learning module at SIR 2025.

‍

Background and Clinical Relevance

Knee OA is among the most prevalent musculoskeletal disorders globally, imposing significant pain, disability, and socioeconomic costs [5]. Conventional treatments include lifestyle modifications, physical therapy, and medications. Knee replacement surgery is reserved as a last resort for those with end-stage knee OA, yet many patients with mild to moderate knee OA experience inadequate relief from conventional treatment options [5]. Moreover, with the rising incidence of knee OA, there is an increasing need for alternative therapies that can delay or reduce the requirement for major surgical interventions [5].

In 2015, Dr. Yuji Okuno introduced GAE as a new treatment option [1]. Although robust evidence is still developing, early studies have shown encouraging results regarding both safety and efficacy, suggesting that GAE is a promising alternative for patients who have not experienced sufficient relief from traditional therapies [3, 4]. The underlying concept of GAE is to reduce blood flow to the inflamed synovium by “pruning” the abnormal neovessels within the knee, which appears to alleviate synovitis and disrupt the chronic pain cycle [1, 2]. Nonetheless, further research is needed to firmly establish the long-term benefits and clinical role of this promising modality [3].

Anatomical Considerations and Procedural Technique

A comprehensive understanding of knee anatomy is critical for the successful application of GAE [2, 6]. The genicular arteries form an intricate vascular network around the knee, and anatomical variations and collateral pathways can influence both the safety and efficacy of the procedure [2, 6]. Detailed pre-procedural planning and training are essential.

During the procedure, interventional radiologists gain vascular access via the femoral, radial, or pedal arteries using the Seldinger technique, advancing a microcatheter to selectively target the arteries supplying the painful areas of the knee with the use of digital subtraction angiography [1, 2, 6]. The relevant vessels are then examined for the presence of a characteristic "blush" that signals hypervascularity resulting from chronic inflammation. When a blush is observed, embolic agents—ranging from resorbable particles to permanent calibrated microspheres—are carefully injected [1, 6, 7]. The choice of embolic material depends on local preferences and regulatory approvals, and it is important to note that evidence on long-term outcomes remains preliminary, so current recommendations should be interpreted with caution [2, 3].

Role of Simulation in Advancing GAE Training

As GAE continues to emerge as a promising treatment for knee OA, the need for specialized, risk‐free training becomes paramount. Simulation-based training provides an ideal environment for radiologists to practice the entire GAE procedure—from gaining vascular access and navigating complex knee anatomy to the precise embolization of target vessels. This hands-on approach not only builds technical skills but also deepens the understanding of anatomical variations and potential complications. Additionally, simulation training can help standardize the procedure across centers, which is critical for comparing research outcomes and strengthening the evidence base over time. By merging advanced imaging, precise procedural techniques, and simulation-based practice, we are preparing clinicians to safely and effectively implement GAE. This combined approach will be a key focus at our upcoming SIR 2025 hands-on session.

‍

Keys to Successful GAE Implementation

Achieving optimal outcomes with GAE requires a comprehensive approach that includes patient selection, interdisciplinary collaboration, and continuous evaluation and training. Successful GAE programs build on the following principles:

• Patient Selection: Identifying appropriate candidates is critical. Patients with mild-to-moderate knee osteoarthritis who have not found adequate relief from conventional treatments appear to benefit from GAE [3, 4]. Data from patients with severe OA have shown divergent results, and more robust evidence is needed to definitively determine the optimal patient group for GAE [3, 4]. It has also been suggested that pre-procedural imaging can help identify which OA patients have synovitis and are therefore expected to benefit most from GAE treatment [8, 9].
• Interdisciplinary Collaboration: The implementation of GAE benefits from close collaboration among interventional radiologists, orthopedic surgeons, rheumatologists, and physiotherapists. This multidisciplinary approach ensures that patient care is comprehensive and individualized, from initial evaluation to post-procedural rehabilitation.
• Continuous Evaluation and Training: Given the current limitations in the evidence base, ongoing research and continuous training are essential. Simulation-based modules serve not only as educational tools but also as platforms for sharing best practices and refining procedural protocols based on the latest clinical findings.

‍

Perspectives

Large, randomized controlled trials with extended follow-up periods are necessary to determine the long-term efficacy and safety of GAE and its role in clinical practice [2–4]. Additionally, future research should aim to refine patient selection criteria and optimize embolic materials to reduce complications and improve patient outcomes. Collaborative efforts among research institutions and clinical centers globally are important to thoroughly explore the potential of GAE as a treatment option [2].

‍

Conclusion

GAE offers a promising approach to managing pain and functional limitations associated with knee OA. This patient group is often insufficiently relieved by conventional treatment regimens, and given the significant personal and societal costs, the need for alternative therapies is of global interest. Interest in GAE has exploded in recent years, even though the current evidence is not yet robust enough to draw definitive conclusions about its clinical potential, long-term effects, and socioeconomic benefits.

The successful implementation of GAE in both clinical practice and research settings requires interdisciplinary collaboration and hands-on training. Moreover, international partnerships and comparable research outcomes are key factors for effectively optimizing the evidence and understanding of this treatment.

As we prepare to launch our new GAE simulation module, we invite interventional radiologists and other healthcare professionals to join us at SIR 2025 in the US for an exclusive hands-on experience. Explore the potential of this cutting-edge treatment and join us at the forefront of a new era in interventional radiology. We welcome your feedback and look forward to engaging with the community as we continue to explore and refine this promising treatment modality.

‍

If you are interested in learning more—or would like to be among the first to explore the GAE simulation module—please fill out this form.

‍

References

1. Okuno Y, Korchi AM, Shinjo T, Kato S(2015) Transcatheter Arterial Embolization as a Treatment for Medial Knee Painin Patients with Mild to Moderate Osteoarthritis. Cardiovasc Intervent Radiol38:336–343

2. Sajan A, Epelboym Y, MartínezAF, Little M, Talaie R, Isaacson A (2025) Transarterial Embolization forMusculoskeletal Pain Management: AJR Expert Panel Narrative Review. AmericanJournal of Roentgenology 224:e2431626

3. Chlorogiannis D-D, VasilopoulouA, Konstantinidis CI, Pagona AE, Filippiadis DK (2024) Knee pain improvementafter genicular artery embolization for the management of knee osteoarthritis:an updated systematic review and meta-analysis of 21 studies. Die Radiologie64:32–46

4. Hindsø L, Riis RGC, Hölmich P,Petersen MM, Nielsen MB, Lönn L, Taudorf M (2021) Current Status ofTrans-Arterial Embolization in Pain Management of Musculoskeletal InflammatoryConditions - An Evidence-Based Review. Cardiovasc Intervent Radiol 44:1699–1708

5. Hunter DJ, Schofield D,Callander E (2014) The individual and socioeconomic impact of osteoarthritis.Nat Rev Rheumatol 10:437–441

6. Little MW, Gibson M, Briggs J,et al (2021) Genicular artEry embolizatioN in patiEnts with oSteoarthrItiS ofthe Knee (GENESIS) Using Permanent Microspheres: Interim Analysis. CardiovascIntervent Radiol 44:931–940

7. Sapoval M, Querub C, Pereira H,et al (2024) Genicular artery embolization for knee osteoarthritis: Results ofthe LipioJoint-1 trial. Diagn Interv Imaging 105:144–150

8. Zadelhoff TA van, Okuno Y, BosPK, Bierma-Zeinstra SMA, Krestin GP, Moelker A, Oei EHG (2021) Associationbetween Baseline Osteoarthritic Features on MR Imaging and Clinical Outcomeafter Genicular Artery Embolization for Knee Osteoarthritis. Journal of Vascularand Interventional Radiology 32:497–503

9. Hindsø L, Hölmich P, PetersenMM, et al (2024) Reduction in Synovitis Following Genicular Artery Embolizationin Knee Osteoarthritis: A Prospective Ultrasound and MRI Study. Diagnostics14:2564

‍