Vol 10, No 2 (2004)
Research paper
Published online: 2004-05-10
Carotid plaque instability in symptomatic carotid disease
Acta Angiologica 2004;10(2):67-76.
Abstract
Background. The currently accepted criteria for carotid endarterectomy
are closely related to the severity of carotid artery stenosis, combined with
the presence or absence of neurological symptoms. Recently, it has been advocated,
that some of the atheromatous lesions not necessarily qualified for surgery may
be unstable, thus leading to increased incidence of neurological symptoms. The
aim of the study was to determine the relationship between the morphology of the
carotid plaque and the risk of increased microembolism during the carotid endarterectomy.
Material and methods. Fifty-two patients were evaluated, while being treated for internal carotid artery stenosis. Among this cohort, 56 endarterectomies were performed (4 patients had bilateral carotid endarterectomies in the period of evaluation. The following data were taken into analysis during this study: the degree of carotid stenosis, morphology of the carotid plaque (GSM); during the surgery, the following elements of blood flow in the medial cerebral artery (MCA) were registered - microembolism, Vav, Vmax and PI. All these parameters were registered using a transcranial Doppler (TCD). The periods of observations were divided into 3 stages (stage I - dissection of arteries, stage II - clamping time, and stage III - after the release of the clamps).
Results. The comparative results of the analysis revealed that in the first group of patients with hipoechogenic, "soft" plaques (GSM < 50) there was a significant increase in the amount of microemboli released during stage I of the operation, than in the II group having hiperechogenic plaques (GSM > 50) - p = 0.002. Also, the cumulated amount of microemboli during all the stages of the operation was significantly higher in group I (p = 0.005).
Conclusions. There is a direct relationship between the carotid plaque echogenicity and the perioperative morbidity related to the amount of microembolism. The results of the study suggest correlation between the plaque morphology and its stability, indicating the necessity for further investigation.
Material and methods. Fifty-two patients were evaluated, while being treated for internal carotid artery stenosis. Among this cohort, 56 endarterectomies were performed (4 patients had bilateral carotid endarterectomies in the period of evaluation. The following data were taken into analysis during this study: the degree of carotid stenosis, morphology of the carotid plaque (GSM); during the surgery, the following elements of blood flow in the medial cerebral artery (MCA) were registered - microembolism, Vav, Vmax and PI. All these parameters were registered using a transcranial Doppler (TCD). The periods of observations were divided into 3 stages (stage I - dissection of arteries, stage II - clamping time, and stage III - after the release of the clamps).
Results. The comparative results of the analysis revealed that in the first group of patients with hipoechogenic, "soft" plaques (GSM < 50) there was a significant increase in the amount of microemboli released during stage I of the operation, than in the II group having hiperechogenic plaques (GSM > 50) - p = 0.002. Also, the cumulated amount of microemboli during all the stages of the operation was significantly higher in group I (p = 0.005).
Conclusions. There is a direct relationship between the carotid plaque echogenicity and the perioperative morbidity related to the amount of microembolism. The results of the study suggest correlation between the plaque morphology and its stability, indicating the necessity for further investigation.
Keywords: volunerable carotid plaqueatherosclerosisultrasonography