Abstract No. 500 Development of a Novel Swine Model for Lumbar Artery Embolization

To establish an animal model for lumbar artery embolization (LAE) that is technically feasible and may be used in future studies investigating LAE, an emerging potential treatment for lower back pain. Two Yorkshire swine were subjected to percutaneous induced degeneration of four lumbar intervertebral discs. 6-8 weeks later, the swine underwent fluoroscopic-guided LAE at 2 levels corresponding to 2 of the 4 degenerated discs. Catheterization of each lumbar artery was performed using a 5 french catheter, and a microcatheter was used to deliver 100um microspheres into the lumbar arteries in a non-selective fashion for the first pig, and 400um microspheres selectively into branches supplying the intervertebral discs for the pig 2. Cone-beam CTA was utilized for pig 2. The lumbar artery embolization procedure was successfully performed on both Yorkshire Swine under fluoroscopy. In pig 1, despite no obvious communication to the anterior spinal artery (ASA) observed on angiography and no significant vascular communications documented in the literature, the swine experienced paralysis of the hind legs post-procedure. For pig 2, cone-beam CT angiography revealed previously unknown, clear communications to the ASA. Therefore, selective embolization of the branches supplying the disc spaces was performed in pig 2 to avoid these communications. The size of the particles utilized was also increased from 100um to 400um to decrease the risk of non-target embolization of the spinal cord. Lumbar artery embolization was found to be technically feasible in this novel porcine discogenic back pain model. Paralysis in the first swine highlights the importance of anatomical variability, and potential risks associated with this procedure even in humans. The previously undescribed communication between the porcine lumbar artery and the ASA at multiple levels underscores the need for vascular mapping and understanding of individual variations before performing LAE. This new information regarding arterial communications between the lumbar artery and the ASA in a swine model is useful for future translational study design.