EVALUATION OF A MODULAR ENDOVASCULAR BIFURCATION PROSTHESIS IN A CANINE AORTIC-ANEURYSM MODEL

Purpose: The study evaluated the deployment and healing of a novel sel f-expanding modular bifurcation endovascular prosthesis in a canine ab dominal aortic aneurysm model. The endoluminal prosthesis consists of self-expanding nitinol stents lined by a synthetic prosthesis. One com ponent of the device is a bifurcated body with a 12- to 14-mm diameter aortic segment and an integral 7- to 8-mm diameter iliac limb. The bi furcated body also has a stent-reinforced opening (pant-leg) for subse quent insertion of a contralateral 7- to 8-mm diameter iliac limb comp onent. Methods: Seventeen bifurcated prosthesis were placed; 7 were in serted through the left common carotid artery and 10 from the femoral arteries. With either route of access the 16F or 17F aortoiliac limb a nd the 13F iliac limb delivery catheters enabled easy passage and secu re positioning of the bifurcated prostheses. Predeployment and postdep loyment inspection of the dimensions and continuity of the aortoiliac prosthetic components were evaluated by cinefluoroscopy and intravascu lar ultrasonography (IVUS). Results: After deployment: was done, inter val patency was assessed with angiography, NUS, and contrast-enhanced computed tomography with the prostheses removed for analysis at 1 week (n = 4), 1 month (n = 3), 3 months (n = 4), and 6 months (n = 6). Fiv e of the first seven implanted prostheses had occlusion of segments of the device. In two dogs the bifurcated body and both legs n ere occlu ded. In the ether three the nonoccluded leg and bifurcation body were fully patent. In the first seven animals IVUS at implantation showed c ompression of an iliac leg by the orifice of the contralateral iliac c omponent. After concentric fixation of the flow divider was performed, only one additional iliac limb occlusion occurred in the next 10 anim als. Cinefluoroscopy, computed tomography, NUS imaging, and histologic analysis of retrieved specimens demonstrated healing of the aortoilia c prostheses without evidence of perigraft leaks. Conclusions: This fe asibility study demonstrates the ability to deploy and maintain accept able patency of a self-expanding endoluminal, modular bifurcation pros thesis in a canine aortic model. Clinical evaluation of the device is planned for the near future.