Strategy of Treatment for Anterior Cerebral Artery Dissection

Spontaneous dissection of the anterior cerebral artery (ACA) is an unusual condition, and the natural history of the intracranial arterial dissection is not well known. We report our surgical strategy for the dissection of ACA. In our series of ACA dissections, 5 cases presented an ischemia and 1 showed an SAH. Case 1 showed the dissection of the A2 portion of the ACA presenting weakness of the right lower extremity. According to Yonas et al., the dissection between the internal elastica and the media causes a cerebral ischemia and the dissection between the media and the adventitia causes an SAH. In Case 1, the pathological study revealed a dissection between the media and the adventitia in spite of a cerebral ischemia. Case 3 after initial headache showed a mild paresis of the right leg and the dissection of A2, A3 portion of ACA in the repeated angiography. The pericallosal-pericallosal side-to-side anastomosis and callosomarginal artery-callosomarginal artery side-to-side anastomosis with the ligation of the proximal A2 portion was performed. The pseudo lumen was detected in the anterior internal frontal artery after the arteriostomy. Preoperative left CAG did not reveal a double lumen sign but mild stenosis of the anterior internal frontal artery. This is the first report of intraoperative detection of intracranial arterial dissecting pseudo lumen. Obliteration of the dissecting entry in the surgical treatment of arterial dissection is essential. Therefore, it is considered that the trapping of the dissection and the revascularization of the ACA is necessary to prevent postoperative infarction and future rupture of the dissection. The pressure in the true lumen of the dissecting vessels is elevated by producing A3-A3 anastomosis, and the increasing pressure of the true lumen will compress the pseudo lumen after the blocking of the entry. We conclude that the occlusion of the entry and revascularization for the dissecting arteries might be the first choice in the surgical treatment for the patients of ACA dissection.