Vasa Vasorum Arteriopathy: Relationship With Systemic Arterial Hypertension and Other Vascular Lesions in Cats.

The vasa vasorum is a delicate network of small arterioles that supplies nutrients to the adventitia and outer media of large arteries. In humans, dysfunction of the vasa vasorum contributes to the pathogenesis of aortic dissection and atherosclerosis. Twenty-four cats from 1 to 18 years of age were prospectively evaluated. Cases were divided into 3 cohorts-with systemic hypertension, without systemic hypertension, and uncertain. Histologic sections of the aorta and main pulmonary artery, as well as sections of kidney and lung, were blindly examined by 2 pathologists. The severity of vasa vasorum arteriopathy was compared to the presence of renal arteriosclerosis, aortic medial degeneration, subintimal fibroplasia of the main pulmonary artery, and blood pressure. We found that vasa vasorum arteriopathy correlated strongly with hypertensive status, degree of renal arteriosclerosis, and lesions in the great vessels. The positive predictive value of a severe vasa vasorum score for systemic hypertension was 84.6%. Lesions of vasa vasorum arteriopathy were predictive of renal arteriosclerosis with 100% sensitivity and 64.7% specificity. The positive predictive value of a severe vasa vasorum score for the presence of aortic lesions was 69.2% vs 91.6% for lesions in the main pulmonary artery. The vasa vasorum appears to be an important responder to systemic hypertension in cats, and arteriopathy of this vascular bed has significant implications for the integrity of the great vessels.