Abstract TP77: Novel Experimental Aneurysm Model in Swine With Hemodynamic Change After Endovascular Treatment; "Recanalization and Regrowth Model"

Abstract

Introduction: Very few animal model can simulates aneurysmal growth and recanalization after endovascular treatment. It was indicated that swine aneurysm model has increased thrombogenicity, which can lead to better healing. We modified the aneurysm model by inducing double anti-platelet therapy to reduce thrombogenisity. It was to establish a large animal model with improved patency, and moreover simulating the recanalization followed by aneurysmal growth. This study is to evaluate reproducibility and feasibility of the modified swine aneurysm model for the evaluation of new endovascular devices. Methods: Sidewall aneurysm was surgically created on the bilateral carotid arteries using a vein graft. A total of eighteen aneurysms were created in 9 swine. Endovascular treatment was performed just after the creation. Aspirin 100mg and clopidogrel 75mg were given five days prior to the surgery and kept until harvesting at day14. Endovascular treatment was performed in following device combinations: coil embolization with stent (n=11) and coil alone (n=7). Volume Embolization Ration (VER) was measured in every aneurysm. Results: Mean aneurysm neck size was 6.3mm, and mean fundus size was 9.5mm. Mean VER was 9.9%. Recanalization or aneurysmal rupture was seen on 83.3% (n=15). Average VER is significantly lower in ruptured group than that in un-ruptured group (7.3% vs. 11.6%, P<0.001). Mortality rate due to aneurysmal rupture was 27.7%. However, after the amendment of the protocol with higher VER, the mortality rate was reduced. Recanalization was observed along with the inflow-area in representative cases. The histologic analysis showed recanalized component, which was consistent with the CFD results (Figure). Conclusion: The modification in the swine aneurysm model reproduced the recanalization and aneurysmal growth after the treatment. This model may contribute to the evaluation of the new endovascular devices by simulating the similar clinical settings.