Echomorphologic and histopathologic characteristics of unstable carotid plaques

BACKGROUND AND PURPOSE: Our hypothesis was that the carotid plaques associa ted with retinal and cerebrovascular symptomatology and asymptomatic presen tation may be differ from each other, The aim of this study was to identify the sonographic and histopathologic characteristics of plaques that corres ponded to these three clinical manifestations. METHODS: The echo process involved duplex preoperative imaging of 71 plaque s (67 patients, 21 plaques were associated with retinal, 25 with cerebrovas cular symptoms, and 25 were asymptomatic), which was performed in a longitu dinal fashion. Appropriate frames were captured and digitized via S-video s ignal in a computer and digitized sonograms were normalized by two echo-ana tomic reference points: the gray scale median (GSM) of the blood and that o f the adventitia. The GSM of the plaques was evaluated to distinguish dark (low-GSM) from bright (high-GSM) plaques. Subsequent to endarterectomy, the plaques were sectioned transversely, and a slice at the level of the large st plaque area was examined for the relative size of necrotic core and pres ence of calcification and hemorrhage. RESULTS: Retinal symptomatology was associated with a hypoechoic plaque app earance (median GSM: 0), asymptomatic status with a hyperechoic plaque appe arance (median GSM: 34), and cerebrovascular symptomatology with an interme diate plaque appearance (median GSM: 16) (P = .001), The histopathologic ch aracteristics did not disclose differences between the three clinical group s. The hypoechoic plaque appearance was associated only with the presence o f hemorrhage (median GSM for the hemorrhagic plaques, 6, and for the non-he morrhagic ones, 20 [P = .04]), The relative necrotic core size and the pres ence of calcification did not show any echomorphologic predilection. CONCLUSION: Our results showed that distinct echomorphologic characteristic s of plaques were associated with retinal and cerebrovascular symptomatolog y and asymptomatic status. Histopathologically, only the presence of hemorr hage proved to have an echomorphologic predilection.