Dissection from fundus to neck for ruptured anterior and middle cerebral artery aneurysms at the acute surgery.

It is generally believed that a ruptured aneurysm should be dissected from its neck to its fundus or that only the neck should be dissected. This study was conducted to clarify whether, during the acute stage, intra-operative bleeding occurs at the same site as the initial rupture point when aneurysms are dissected completely without clipping. The subjects were 170 patients with ruptured anterior or middle cerebral artery aneurysms who were surgically treated by day 7. These aneurysms were operated on through an interhemispheric or a pterional route, respectively. Most of the aneurysms were dissected from the fundus to the neck. Complete exposure of entire aneurysms without temporary clipping was performed in 118 of 170 patients (69%). Intra-operative aneurysmal rupture occurred during 16 (9%) operative procedures. There were no significant correlations between the rate of intra-operative aneurysmal rupture occurrence and the timing of the operation, pre-operative grade or location of ruptured aneurysms. Intra-operative aneurysmal rupture occurred during dissection of the aneurysm itself in 8 patients, during dissection of the artery adhering to the aneurysm in 5 and during clip application in 3. In all the patients whose aneurysms ruptured during aneurysmal dissection, the rupture was caused by injury to the aneurysm and was not directly related to complete exposure of the aneurysm. Intra-operative bleeding did not occur at the same site as the initial rupture point even when the entire aneurysmal complex was dissected from the fundus to the neck without clipping.