Ruptured distal middle cerebral artery aneurysm

Object. Ruptured distal middle cerebral artery (MCA) aneurysms are uncommon, and their clinical and radiological features are poorly understood. To clarify characteristics of these lesions, the authors undertook a retrospective analysis of nine patients with ruptured distal MCA aneurysms.

Methods. The medical records of patients who underwent surgical repair of ruptured intracranial aneurysms between 1988 and 2002 at Shinshu University Hospital and its affiliated hospitals were retrospectively evaluated. The authors found only nine patients with a ruptured distal MCA aneurysm, and their clinical, neuroimaging, and intraoperative findings were evaluated.

Conclusions. This study of nine patients with distal MCA aneurysms is the largest series to date. Eight lesions were saccular aneurysms that were clipped and the remaining one was a mycotic aneurysm that was trapped. Eight of the nine patients suffered cerebral hematomas with subarachnoid hemorrhage. All patients had good outcomes after obliteration of their aneurysm, although their preoperative condition was not good.

Microsurgical anatomy of the early branches of the middle cerebral artery: morphometric analysis and classification with angiographic correlation

OBJECT

The cortical arteries arising from the main trunk of the middle cerebral artery, proximal to its bifurcation or trifurcation, are called "early branches." The purpose of this study was to characterize these early branches.

METHODS

The early branches were characterized according to their sites and patterns of origin, diameters, and relative proximity to the internal carotid artery bifurcation, as well as the course and area of supply of their cortical branches based on an examination of 50 hemispheres. Special attention was directed to the perforating arteries that arose from the early branches and entered the anterior perforated substance. The anatomical findings were compared with data obtained from 109 angiograms.

CONCLUSIONS

Early branches directed to the temporal and frontal lobes were found in 90 and 32% of the hemispheres, respectively. The early branches that arose more proximally from the M1 segment were larger than those arising distally. Lenticulostriate arteries arose from 81% of the early frontal branches (EFBs) and from 48% of the early temporal branches (ETBs). An average of two cortical arteries arose from the EFBs and 1.3 from the ETBs, the most common of which supplied the temporopolar and orbitofrontal areas. Although the microsurgical anatomy of the early branches demonstrates abundant diversity, they can be classified into clearly defined patterns based on anatomical features. These patterns can prove helpful in evaluating angiographic data and in planning an operative procedure.