No abstract

Middle cerebral artery (MCA) aneurysms comprise 20-25% of all intracranial aneurysms. The majority of middle cerebral artery aneurysms are treated by microsurgical clipping. Most of the classifications of aneurysms at present are based on size, location or pathology which are effective for the description but are less useful in preoperative planning and also in deciding on the technique or type of clip application. The aim of our study was to examine the morphological features of unruptured MCA bifurcation aneurysms which influence the techniques of clipping of these aneurysms and to attempt to subclassify unruptured middle cerebral artery aneurysms based on their preoperative 3D CTA and intraoperative characteristics so as to help in the intraoperative choice of technique and clip application, respectively. Preoperative 3D CT angiography and intraoperative images along with the record of technique and type of clips used for 141 unruptured MCA aneurysms operated at our center were studied retrospectively. Unruptured MCA bifurcation aneurysms could be subclassified into 5 types based on the similarities in their morphological features which influenced the techniques of clipping as recorded from their preoperative 3D CTA and intraoperative view. These types and the distinctive feature of each type are described. The various techniques of clipping are discussed based on these subgroups. The groups outlined make possible the establishment of a common technical approach to clipping within the groups. This classification, based on preoperative 3D CTA and intraoperative morphological features of the aneurysm and parent vessels, helps in the intraoperative choice of technique and type of clip application to tackle these lesions.

A 53-year-old woman was admitted with severe subarachnoid hemorrhage due to rupture of an aneurysm associated with atypical intracranial fibromuscular dysplasia (FMD). Angiography demonstrated the aneurysm and very irregular form of the left internal carotid artery (ICA), the right ICA, and right proximal middle cerebral artery (MCA). Other arteries showed signs of atherosclerosis. The aneurysm was treated by embolization, but she subsequently died of shock of unknown cause. Detailed examination of serial angiograms detected enlargement of the aneurysm and progression of the irregular appearance of the ICA. FMD is a non-inflammatory and non-atheromatous arteriopathy that commonly affects the cervical ICA and sometimes the intracranial ICA. The association with saccular aneurysm is widely known and the prevalence of incidental aneurysms is higher than that in the general population. The common``string of beads'' finding is easily distinguished from other vascular diseases, but non-specific findings such as``tubular stenosis'' and``diverticular-like outpouching'' are harder to differentiate. FMD is associated with various complications and appropriate periodic follow-up examination is required. Detailed analysis of serial angiograms may facilitate diagnosis of this condition.

A 71-year-old woman presented to our care facility with complaints of diplopia and nausea when she rotated her head to the right side. She was neurologically intact and denied experiencing the symptoms when she rotated her head to the left side. Head MRI diffusion-weighted image showed a high-intensity spot in the cerebellum. MR angiography showed hypoplasia of the right vertebral artery (VA). However, the causes of the cerebellar infarction were not detected. We considered the possibility of bow hunter s syndrome and performed ultrasonography during head rotation. However, this failed to detect the flow impairment of VA. Finally, digital subtraction angiography was performed and it was found that the left VA was occluded at the C1-2 level when she rotated the head to the right side. Digital subtraction angiography kymography was useful for the diagnosis of bow hunter s syndrome.

A case of vertebral artery dissection complicated with repeated cerebral embolism