Creation of experimental aneurysms at a surgically created arterial confluence.

Complex vertebral confluence aneurysms remain clinically challenging despite the rapid technological advances in endovascular technology. Therefore, animal confluence aneurysm models are urgently needed for the preclinical development of related medical devices and training clinicians. This study aimed to establish canine confluence aneurysm model and evaluate hemodynamics in this model. According to the shape and regional blood flow of vertebrobasilar junction (VBJ) aneurysms, confluence aneurysm was introduced in 9 dogs by microsurgical technique. We partially anastomosed right common carotid artery (CCA) and left CCA (end to side anastomosis) to create inverted Y-junction of arteries and, then, sutured a harvested segment of external jugular vein to the notch of anastomosis to simulate confluence aneurysm. These animals were examined by 3D digital subtraction angiography (DSA) 4 weeks after surgery. Geometry parameters of the aneurysm, surrounding vasculature and specific double inlet profiles were analyzed by simulating computational fluid dynamics (CFD) in these animals. Aneurysms were successfully established in all animals, including 8 complete and 1 partially thrombosed aneurysms. No neurological defects or death were observed. Geometric and hemodynamic parameters in these surgically introduced confluence aneurysm animals are similar to those reported for human VBJ aneurysms. This study documents a protocol to successfully establish confluence aneurysm models in dogs. This model may be useful in preclinical studies targeting various complex vertebral confluence aneurysms.