Difficulties in examination of the origin of the vertebral artery by duplex and colour-coded Doppler sonography: anatomical considerations

Abstract

Despite progress in ultrasonographic techniques visualisation of the origin of the vertebral arteries, particularly the left, by duplex and colour Doppler imaging, still poses a problem in a significant number of patients. In anatomical and radiological studies we demonstrated an anomalous origin in 6%, the left vertebral artery originating directly from the aorta in most cases. The origin from the subclavian artery was found to be posterior in 44% and inferior in 6%. The V1 segment of the vertebral artery (from its origin to the entry into the foramen transversarium) was tortuous in 47% of cases. These anatomical variants and variations in the course of the vessel contribute to the nonvisualisation of the origin of the vertebral artery by duplex and colour Doppler imaging. With respect to tortuosities technical modifications for better visualisation are suggested and possible implications for surgery are discussed.

Anatomical Features and Clinical Importance of the Vertebral Artery

“…The main plane of the tortuosity was transverse in 42.5%, sagittal in 30% and frontal in 27.5% [14].…”

“…Several researches have reported anomalous origin, in which origin point of the VA is from the aortic arch [1,[8][9][10][11][12][13][14][15], from the thyrocervical trunk [1,14,16], from the brachiocephalic trunk [6], from the common carotid artery [1,14,17], and from the external carotid artery [1,12,14]. Though the overall incidence of the anomalous origin of the VA is low, it occurs mostly on one side, usually on the left [11,12].…”

“…2). A suggested congenital origin is difficult to assess since tortuosity has been shown to increase with age [14].…”

“…However, loops of the vessel have been described to cause several problems. Loops of the VA have been reported to cause radicular symptoms via nerve root compression [1,14]. The VA loop formation is one of those infrequent causes which can cause pressure erosion of the adjacent vertebral body, widening of the intervertebral foramen and compress the cervical nerve root causing cervical radiculopathy [33].…”

“…Cervicobrachial neuralgia produced by vascular compression presents with paraesthesia and dysaesthesia of the fingers without a triggering factor, the lack of nocturnal symptoms, and the rarity of neurologic deficits [33]. Symptomatic loops may be corrected by a bypass procedure [1,14].…”