Irregular neointimal lining with prominent proliferative activity after carotid patch angioplasty: an autopsy case...

Although the healing response after carotid balloon injury and carotid patch angioplasty injury has been well-documented in animal models, there is limited information about this process after carotid endarterectomy (CEA) in human patients.

We describe the autopsy results of a 79-year-old man who died 18 days after CEA with patch angioplasty. The treated carotid artery had an adequate luminal diameter. Elastica-Masson staining revealed that the treated portion was covered with neointima but the patch graft was exposed to the arterial lumen at 18 days after CEA. Immunohistochemistry staining for alpha-smooth muscle actin (α-SMA), von-Willebrand factor, and vascular endothelial growth factor receptor-2 revealed that the neointima was mainly composed of α-SMA-positive cells. In addition, the α-SMA-rich neointima had many more Ki-67-positive cells than did the internal carotid artery intima in the area beyond the CEA-treated portion.

This case report is the first to describe an entire carotid artery specimen in the acute stage after CEA with patch angioplasty. These findings suggest that an α-SMA-rich neointima with prominent proliferative activity covers the inner surface of the treated carotid artery, but patch grafts are left uncovered. The intrinsic arterial wall may have an important role in intimal regeneration after CEA, although the nature of the neointima and the mechanism by which it regulates proliferative activity remain unclarified.