Abstract

Coarctation of the thoracic aorta was produced in 9 adult Yucatan mini pigs. A gradually aortic constriction was accomplished by placing a “C” shaped expandable occluder around the thoracic aorta. The aortic constriction was standardized by measuring the blood pressure above the coarctation with 165-170mm Hg mean arterial pressure as the target. The gradual occlusion of the aorta was performed over a period of 15 days. The pigs were studied for 4 (n=3) and 8 (n=5) weeks of cranial hypertension and then euthanized. Three animals served as controls. There were no deaths associated with placement of the occluder or constriction of the aorta and neither rear limb weakness nor neurologic dysfunction were noted. Aortic angiography demonstrated a severe grade of stenosis and extensive collateral circulation in the 8-week study pigs. This study showed that gradual coarctation of the thoracic aorta in adults and mature minipigs produces chronic and cranial hypertension and is associated with development of an extensive collateral circulation after 8 weeks of the study. The purpose of this work is to reveal the collateral growth and vascular patterns developed around the coarctation. To our knowledge, this collateral circulation response has not previously shown under these conditions and proofs that adult porcine individuals can adjust their vasculature to stenotic arterial condition showing dramatical vascular changes in a relatively short period of time.

Keywords: Aortic coarctation; Minipig, Hypertension; Collateral circulation; Angiography