Differentiation between intradural and extradural locations of juxta-dural ring aneurysms by using contrast-enhanced 3-dimensional time-of-flight magnetic resonance angiography.

BACKGROUND: Juxta-dural ring aneurysms of the ICA have different clinical outcomes and risks for SAH, which are dependent on their position in the intradural or extradural space. The aim of this study was to reveal the precise location of such aneurysms by using CE-MRA. METHODS: Contrast-enhanced MRA studies were performed in 21 patients with 24 juxta-dural ring aneurysms. The locations were evaluated by source images of CE-MRA and MPR images. We evaluated the accuracy of preoperative MRI findings by comparing imaging results with intraoperative findings in 7 cases. RESULTS: The CS was clearly enhanced in the CE-MRA technique, which allowed the precise identification of these aneurysms as intradural or extradural. Intracavernous aneurysms were diagnosed when the greater hyperintensity of the aneurysm was located within the less hyperintense region of the contrast-enhanced CS. Nine of the cases were diagnosed as intradural aneurysms, and 15 aneurysms were noted as extradural based on the findings of CE-MRA. Surgery was performed in 7 cases, which included 4 intradural and 3 extradural aneurysms, and the preoperative MRI findings corresponded with the intraoperative findings in all cases. CONCLUSION: Contrast-enhanced MRA and MPR are very useful techniques for determining the location of juxta-dural ring aneurysms.

Artificial cerebral aneurysm model for medical testing, training, and research.

Artificial models of cerebral aneurysms for medical training and testing of medical devices were constructed from corrosion casts of the main cerebral arteries of a human specimen. Three aneurysms with a variety of shapes were simulated at typical locations. Rigid and soft models were made of silicone using the "lost wax" technique. The transparent silicone models were anatomically accurate and reproducible copies of human vascular casts. These models could be connected in a closed circuit that used an electric pump to simulate pulsatile flow. Endovascular procedures and surgical clip application were performed under fluoroscopic or direct visual control. Surgical clipping, endoluminal coil manipulation, and consecutive hemodynamic changes were visualized by digital subtraction angiography and direct observation. The model provides trainee surgeons with an understanding of clinical conditions. New medical devices, such as platinum coils, would be experimentally implanted in the model under stable conditions. These anatomically accurate and reproducible models of cerebral vasculature and aneurysms are valuable for medical testing, training, and research.

[Middle meningeal artery embolization for refractory chronic subdural hematoma: 3 case reports].

The authors present three cases of refractory chronic subdural hematoma (CSDH) treated by embolization of the middle meningeal artery (MMA) after several unsuccessful drainage procedures. The patients were initially treated by the usual method of burr hole and irrigation of the hematoma. After recurrence, several percutaneous puncture and drainage procedures were unable to prevent re-collection of the hematoma. Then the authors embolized the MMA which was thought to be the feeding artery of the outer membrane of the hematoma cavity. No enlargement of the hematoma was seen after embolization and, gradually, complete resolution of the hematoma was obtained. The outcome of the patients was excellent in all three cases. This new therapeutic approach to recurrent CSDH is discussed.