[The anatomic isthmus in the carotid triangle]

In a limited number of surgically treated patients with blunt trauma to the internal carotid artery (ICA), intimal lesions were found at the intersection of the ICA with the hypoglossal nerve (CN XII). Therefore, these clinical findings were investigated in an anatomic study. In two-thirds of these cases, the congenital "anomalous" relationship of ICA and CN XII caused a strangulation phenomenon during extreme turning manoeuvres of the head and neck. On the basis of our clinical intraoperative findings, anatomic studies und reports in the literature, a further mechanism of vascular injury is suggested in this area.