[The aortic arch as the source of a peripheral arterial embolism]

On the day before admission a 68-year-old woman had an acute episode of incomplete ischaemia of the left lower arm. She had no known heart disease and her general condition was unchanged. There were no palpable pulses in the cold and pale lower arm. Sensory and motor functions of the left hand were slightly impaired. Arterial embolisation was suspected.

The blood picture was normal, erythrocyte sedimentation rate 20/50 mm, C-reactive protein elevated to 7.0 mg/l. There was no evidence of clotting abnormality. The resting ECG showed normal sinus rhythm. Doppler ultrasound gave a systolic pressure of 80 mm Hg over the radial artery and 50 mm Hg over the ulnar artery, with a systemic systolic pressure of 140 mm Hg. No intracardiac thrombi were seen on echocardiography. Transoesophageal echocardiography revealed a 2 x 3 cm hypermobile mass in the distal aortic arch, most likely a thrombus as the source of the embolus. Contrast computed tomography and digital subtraction angiography also demonstrated the mass.

At first heparin (bolus of 5000 IU, then 1000 IU/h) was infused. One day after the diagnosis had been established thrombectomy of the aortic arch and embolectomy of the left brachial artery were performed without complication. The patient was discharged on the 15th post-operative day on a maintenance dose of phenprocoumon. Histological examination of the surgical specimen from the aorta showed a separating thrombus on an ulcerating atherosclerotic plaque.

The importance of the thoracic aorta as a source of emboli is often underestimated. Transoesophageal echocardiography is a reliable method to demonstrate aortic thrombi.