[Traumatic cerebral aneurysm: 94 cases from the literature and 5 cases observed by the authors].

Traumatic intracranial aneurysm is rare lesion which is complicated severe head injury. In spite of this rarity, this aneurysm is well known by the fact of high probability of rupture, and high mortality rate. Ninety-four cases of traumatic aneurysms, including 5 cases of our own are discussed. In 94 cases, 83 cases (88.3%) are located at the middle cerebral arteries and/or the anterior cerebral arteries. There are only 2 cases (2.1%) located at the posterior fossa. All of these 94 aneurysms are situated at the peripheral arteries and/or cortical branches, in the distance of Willis' arterial ring. There are 8 cases which lead to be cured spontaneously without any surgical treatment. It was reported by some authors that the traumatic intracranial aneurysms expecting spontaneous healing had some characteristics by the cerebral angiography, such as irregular shapes, and unclear connections from parent arteries. However, these characteristics are sometimes common in the traumatic intracranial aneurysms. Therefore, it is actually difficult to differentiate spontaneous healing aneurysms from deteriorating ones. As for the prognosis of these 79 cases which are able to be examined, the mortality rate of non-surgical group is 4 times higher compared with that of the surgical group, that is the former 40%, and the latter 11%, respectively. According to these facts, authors concluded that the principle therapy of traumatic intracranial aneurysm is surgical treatment.