CASE STUDIES Duplex Evaluation of the Postoperative

Carotid ultrasound plays a primary role follow-ing carotid endarterectomy in the detection of postsurgical complications. Gray-scale, real-time imaging detects and quantifies tissue inter-faces and plaque morphology. Doppler spectral analysis provides quantitative and graphic dis-play of blood flow velocity and direction. Color flow imaging identifies areas of disturbed flow and can aid in detecting surface irregularities by the flow disturbances they create. Power Dopp-ler is useful in detecting slow blood flow and characterizing plaque surface. During a carotid endarterectomy, the diseased intima and part of the diseased media are removed. Postoperative complications fall into the 3 following catego-ries and vary with the postoperative time inter-val. Technical errors occurring within the first month are most often related to surgical prob-lems, such as residual plaque, arterial clamp in-jury, or an intimal flap. Restenosis postopera-tively within the first 3 years results from neointimal hyperplasia, which involves the smooth muscle and fibrous overgrowth of the tissue layer that replaces the intima after surgery. After 3 years, the material causing restenosis is more apt to resemble atherosclerotic plaque with abundant collagen, foam cells, and calcium de-posits, and is commonly associated with the de-velopment of recurrent atherosclerosis. Key words: carotid ultrasound, carotid endar-terectomy, residual plaque, neointimal hyperpla