Cervical Doppler and duplex sonography in type A aortic dissections

Clinical files of 102 surgically treated patients with type A aortic dissection were analyzed retrospectively for neurological symptoms, neurophysiological and neuroimaging findings. Involvement of one or more main branches of the aortic arch was found in 43% of all patients, most frequently affecting the innominate and carotid arteries (40% vs. 25% Aa. subclaviae). Ultrasound examination was performed presurgically in 17 patients, nine of them with neurological symptoms, and revealed dissection in five patients (29%). Three of these five patients presented with preoperative stroke.

Fig. 1

Fig. 2

The collected ultrasonographic findings include: double lumen in one (fig.1) or both common carotid arteries extending to the carotid bifurcation with hemodynamic relevant stenosis of the common or internal carotid artery as well as subclavian or carotid steal syndrome due to dissection of the innominate and subclavian artery. A suggestive Doppler pulse waveform abnormality (fig.2) could be recorded from dissected vessels of all patients, comprising a deep early mid systolic notch which gives a double hump appearance. The underlying mechanism could be herniation of the false into the true arterial lumen leading to temporary obstruction of systolic ejection or recording of blood flow first in the true and then false lumen. Relevant aortic regurgitation causing similar midsystolic abnormalities was not recorded.

Carotid ultrasound follow-up revealed false channel closing and resolving of the recorded stenosis in four patients within twelve months. In one patient with persistent dissection of left common carotid artery, percutaneous transluminal angioplasty with stenting was performed successfully five months after surgery.

Cervical ultrasound is an useful non-invasive technique in the diagnosis and follow-up of aortic dissection extending to the supraaortic vessels. An abnormal Doppler pulse waveform can reveal the first but important hint of an underlying aortic dissection, especially in patients considered for thrombolytic therapy in acute ischemic stroke.