The biologic behavior of balloon hyperinflation-induced arterial lesions in hypercholesterolemic pigs depends on the presence of foam cells.
Lack of a large-animal model of accelerated atherosclerosis has limited study of the biologic behavior of atherosclerotic lesions. We hypothesized that mechanical vascular trauma combined with diet-induced hypercholesterolemia would result in rapid development of complex atherosclerosis-like lesions. Accordingly, we induced deep injury to a carotid artery by repetitive balloon hyperinflations in minipigs that were fed either an atherogenic diet (n = 30) or a standard diet (controls, n = 4) and examined the resultant lesions 1 month later. The neointimal lesions that evolved in 23 patent vessels from cholesterol-fed animals were complex, exhibiting infiltration of smooth muscle and foam cells and evidence of organized thrombus, recent thrombus, hemorrhage, and calcification. Lesions were separable histologically into two groups: foam-cell rich (n = 12), with 33 +/- 10 foam cells per high-power field, and foam-cell poor (n = 11), with 4 +/- 1 foam cells per high-power field. Minipigs with foam cell-rich lesions had higher serum cholesterol levels than those with foam cell-poor lesions (712 +/- 178 vs 468 +/- 240 mg/dL, P < .02). The incidence of intralesional thrombus was also significantly greater in foam cell-rich than in foam cell-poor lesions (50% vs 9%, P < .04). In addition, the degree of luminal stenosis was greater in the presence of lesions containing thrombus compared with those without thrombus (60 +/- 38% vs 30 +/- 29%, P = .05). Lesions in the control animals were fibrocellular and lacked foam cells and thrombus. Thus, hypercholesterolemia appeared to affect lesion composition and behavior.(ABSTRACT TRUNCATED AT 250 WORDS)
Recchia
D
D
Division of Cardiovascular Diseases, Washington University School of Medicine, St Louis, MO 63178, USA.
Abendschein
D R
DR
Saffitz
J E
JE
Wickline
S A
SA
D000818:Animals; D001161:Arteriosclerosis / Q000150:complications* / Q000209:etiology / Q000473:pathology; D002114:Calcinosis; D002339:Carotid Arteries / Q000473:pathology; D002404:Catheterization; D002784:Cholesterol / Q000097:blood; D005487:Foam Cells / Q000473:pathology*; D006485:Hemosiderin / Q000378:metabolism; D006937:Hypercholesterolemia / Q000150:complications*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000473:pathology; D009389:Neovascularization, Pathologic; D013552:Swine; D013556:Swine, Miniature; D013927:Thrombosis / Q000473:pathology
D006485:Hemosiderin; D002784:Cholesterol