INCIDENTAL VASCULAR PATHOLOGY: A CASE OF SUBCLAVIAN ARTERY OCCLUSION DETECTED THROUGH CAROTID ULTRASOUND IN AN ACUTE STROKE PATIENT
By Ming Yeung, Manchester University NHS Foundation Trust
Background:
Ultrasound of the extracranial cerebral arteries is crucial in the assessment of patients with acute stroke symptoms, as it helps to identify significant stenosis or occlusion that could be contributing to cerebral ischemia. Additionally, this imaging modality can reveal incidental pathologies that may influence patient management and prognosis.
Case Summary:
A 79-year-old female presented with acute onset of right facial droop, dysarthria, and dysphasia, prompting an ultrasound assessment of her extracranial arteries. The ultrasound examination revealed significant left internal carotid artery disease and monophasic waveforms in the left subclavian artery. The left vertebral artery demonstrated antegrade flow which is unusual in cases with significant subclavian disease as it often acts as a collateral pathway. Furthermore, a prominent collateral vessel adjacent to the left vertebral artery was noted displaying retrograde flow, however the origin of this collateral vessel could not be traced from the ultrasound scan. Further investigation with CT imaging of the neck and chest identified an anatomical variant where the left vertebral artery arises directly from the aortic arch and a long-standing occlusion of the left subclavian artery just distal to its origin. The collateral vessel observed on ultrasound was determined to be arising from the left vertebral artery supplying the distal subclavian artery beyond the occluded segment.
This case underscores the importance of thorough carotid artery scanning in patients with acute stroke symptoms, not only to identify the primary cause of cerebral ischemia but also to detect incidental findings that may have significant clinical implications. The identification of a collateral vessel arising from the left vertebral artery compensating for the subclavian artery occlusion illustrates the complexity of vascular pathologies that can be encountered. This case highlights the value of integrating ultrasound with other imaging modalities to achieve comprehensive diagnostic insight and guide appropriate patient management.