Microsurgical carotid endarterectomy in rats.

The purpose of this study was to develop an inexpensive experimental model of carotid endarterectomy. Unilateral common carotid endarterectomies 3 mm in length were performed on 25 rats using microsurgical techniques. The pattern of endothelial regrowth after endarterectomy, the pinocytosis of regenerated endothelial cells, and the effects of heparin and thromboxane A2 synthetase inhibitor on thrombus formation were examined 7 days after the resumption of flow. Pinocytotic vesicular transport in endothelial cells was evaluated using horseradish peroxidase. All endarterectomized vessels in both control and drug-treated groups were patent 7 days after operation without apparent mural thrombus formation. Regenerated endothelial cells had spindle-shaped nuclei and cell bodies with long axes oriented parallel to the direction of blood flow. There were several instances where the leading edge of the endothelium at the distal end was reflected back in the distal direction. The extent of the endothelial ingrowth was often greater from the proximal end of the endarterectomy than from the distal end. These observations suggest that hemodynamic force affects endothelial regeneration. Pinocytotic activity was less in the regenerated endothelium than in either the endothelium remaining at the periphery of the endarterectomy or the endothelium of the control animals.