A 68-year-old woman with distal arch aortic aneurysm was admitted. Preoperative magnetic resonance angiography revealed occlusion of the right middle cerebral artery. Single photon emission computed tomography showed decreased cerebral blood flow at rest and decreased reactivity to acetazolamide in the right temporal lobe. At first, a superficial temporal artery to middle cerebral artery anastomosis was made by neurosurgeons. Improvement of both the cerebral blood flow and the reactivity to acetazolamide was confirmed by single photon emission computed tomography 18 days after the operation. Twenty-two days after the operation, a total arch replacement was performed. The postoperative course was uneventful without any neurological complication.

From 1995 till 1998, 21 cases of Stanford type A dissecting aortic aneurysm with a closed false lumen of the ascending aorta were treated in our institute. The patients were medically treated if the diameter of their ascending aorta stayed less than 50mm without recurrent dissection. Patients were categorized into three groups: Groups I, II and IIIR (retrograde dissection), according to the location of the entry analyzed by means of CT, angiography and operative findings. Seven cases of intramural hematoma (IMH) were included in this study. One case in Group II died of rupture and one case in Group IIIR died of multiple embolism caused by atrial fibrillation in the acute phase. One case in Group II died of stroke and one case in Group I died after surgery in the chronic phase. Four cases in Group I and II underwent surgery in the acute phase and five cases in Group I and II underwent surgery in the chronic phase, but only one case of Group IIIR required surgery. Six cases of IMH required surgery. The rates of freedom from operation at four years was 25%, 21% and 83% respectively (p=0.07). Essentially, Stanford type A dissection should be treated surgically even though the false lumen is thrombosed. However, in the case of retrograde dissection accompanied by an entry in the descending aorta, medical treatment may be a strategy option.