Relationship between the calibre of carotid arteries and the configuration of the circle of Willis in healthy older persons.

AIM: Recent papers have pointed out that the severity of brain damage that follows carotid occlusion is largely influenced by the state of integrity and functionality of the circle of Willis. In spite of this, duplex scanning investigation of carotid arteries has traditionally been focused on the assessment of the degree of the stenosis, while other features, such as the calibre of carotid arteries and their possible asymmetry, have often been neglected. The aim of the present paper was to verify, in a cohort of older persons, whether, based on the calibre of internal carotid arteries and their possible asymmetry, abnormalities of the circle of Willis can be predicted. Such information could be used to identify high risk patients in whom the status of the circle of Willis should be investigated by MR angiography.

METHODS

We studied 118 healthy older persons with both duplex scanning investigation of carotid arteries and MR angiography of the circle of Willis.

RESULTS

We found that the finding of abnormal internal carotid artery calibres was always associated with abnormalities of the precommunicating segments either of the anterior or of the posterior cerebral arteries. Abnormalities of communicating arteries did not affect the calibre of internal carotid arteries, but abnormalities of anterior communicating arteries could always be detected by contralateral common carotid artery compression manoeuvres.

CONCLUSION

In conclusion our findings show that, in healthy older persons, duplex scanning investigation of carotid arteries may provide useful information about the integrity and functionality of the circle of Willis. Future studies should confirm our findings in patients with atherosclerotic lesions of internal carotid arteries.