Spontaneous arterial dissection is also known as or subsumes Dissecting aneurysm. -ed.
The first description of spontaneous dissection of the cervical arteries dates back to 1915 (Turnball 1915). However, Anderson and Schechter in 1959 were the first to clearly document a case of spontaneous dissecting aneurysm of the internal carotid artery (de Bray and Baumgartner 2005). The term "dissection," from the Latin verb disseco, implied the separation of anatomic structures along the natural lines by tearing of the connective tissue framework. As it is applied to vascular pathology, it relates to the separation of the different layers that constitute the arterial wall. This process can occur spontaneously, or it may follow blunt trauma to the vessel. Subintimal dissections can cause lumen stenosis, and subadventitial dissections can cause aneurysmal dilatation. Strictly speaking, the lesion of dissection is a “dissecting aneurysm” and includes layers of the normal vessel wall (Guillon et al 1999). The term “pseudoaneurysm” is often used incorrectly for this same purpose, but this term refers to lesions that do not include components of the normal vessel wall. An example of pseudoaneurysm is a posttraumatic event where the vessel wall is severed and adjacent connective tissue maintains a lumen.