A carotid stenosis model in canines

A carotid stenosis model was developed in canines in order to study the eff ects of systemic blood pressure and hemodilution on cerebrovascular perfusi on and metabolism during cardiopulmonary bypass in the setting of significa nt coexistent in? ow stenosis. Under general anesthesia, through a low midl ine neck incision, the carotid sheath was entered and the carotid artery wa s isolated and retracted medially. The vertebral artery could be identified posterolaterally. After ligating the vertebral artery with a 00 silk tie, carotid stenosis was created by tying bilateral carotid arteries over an 18 -gauge needle using a 00 silk tie. The needle was then removed, leaving a t ight stenosis. To determine the degree of stenosis, arteriograms were perfo rmed, revealing high-grade lesions of greater than 90% stenosis in the caro tid arteries and absence of ? ow through the vertebral arteries. Cerebral b lood ? ow studies during cardiopulmonary bypass (CPB) were performed, revea ling a significant decline. Carotid arteries were harvested at the conclusi on of the experiments, revealing tight lesions on direct inspection. The me an gradient measured across stenotic segments was >25 mm Hg. In conclusion, a carotid stenosis model can be created successfully in dogs by ligating t he vertebral arteries bilaterally and simply using the shaft of a needle to standardize the lumen size of the carotid arteries. We found the diameter of an 18-gauge needle sufficient to produce stenoses of greater than 90% as evidenced by arteriograms.