Retrograde embolism from the descending aorta: visualization by multidirectional 3D velocity mapping in cryptogenic...

Area of Science:

• Cardiovascular Imaging
• Neurology
• Vascular Medicine

Background:

• Complex plaques (≥4 mm) and thrombi in the descending aorta (DAo) are potential sources of embolism.
• The embolic potential of DAo plaques as a stroke source remains incompletely understood.

Purpose of the Study:

• To determine the role of complex plaques in the descending aorta (DAo) as an embolic source for stroke.
• To investigate the relationship between DAo plaque characteristics and stroke etiology.

Main Methods:

• Prospective assessment of brain ischemia territory and embolic pattern in 63 acute stroke patients undergoing TEE.
• Multidirectional 3D MRI velocity mapping of the aorta to correlate retrograde diastolic blood flow with plaque distance from the left subclavian artery (LSA).

Main Results:

• Complex DAo plaques were found in 33 of 63 patients.
• Retrograde flow connected complex DAo plaques with the LSA in 20 patients (31.7%).
• Four patients experienced embolic strokes in posterior circulation territories, unexplained by other causes, linked to this retrograde flow.

Conclusions:

• Multidirectional 3D MRI velocity mapping detected significant diastolic retrograde flow from complex DAo plaques.
• This retrograde flow represents a previously undemonstrable stroke mechanism originating from the descending aorta.