Endovascular therapies for intracranial aneurysms requires animal models for testing the safety andeffectiveness prior to translation to the clinic. Rabbits combined with the elastase and right commoncarotid artery (RCCA) ligation methods is currently a widely used animal model for endovascular de-vice testing. However, the injection of elastase utilizing angiocatheters may potentially exerts adversetorque to the parent vessel and the optimal aneurysm creation period has not been well investigated.In this study, we present a modification to the elastase/RCCA-ligation method by replacing the angio-catheter with a butterfly catheter. Formation of saccular aneurysms was introduced in New Zealandwhite rabbits (n=6), and were maintained for 2, 4 and 6 weeks. The formed aneurysms exhibitedan elongated geometry and were stable during the study period. We found that the modification inthe animal surgery procedure provides improved manipulation of the surgical area, prolonged injec-tion of elastase, and effective degradation of the vascular elastic lamina. Compared to the traditionalelastase/RCCA-ligation method, the present technique can more effectively reduce unwanted injury tothe parent vessel and, therefore, improved stability of the vasculature for testing the efficacy of newlydeveloped endovascular embolization devices.