[Embolization for aneurismal dilatation associated with ruptured dissecting anterior inferior cerebellar artery aneurysm with preservation of the parent artery: case report].

We report a rare case of a ruptured dissecting anterior inferior cerebellar artery (AICA) aneurysm treated by endosaccular embolization with a Guglielmi detachable coil (GDC). An 85-year-old female presented with headache. Computed tomographic (CT) scan showed subarachnoid hemorrhage and intraventricular hemorrhage in the fourth ventricule. Cerebral angiography and 3D-CT angiography revealed an aneurysmal dilatation at the anterior pontine segment of the right AICA with a diagnosis of arterial dissection. The right posterior inferior cerebellar artery (PICA) was absent and the right AICA supplied the territory normally nourished by the right PICA. The aneurismal dilatation was occluded by endosacullar embolization with preservation of the AICA. The distal AICA aneurysm is rare and only seven cases treated with endovascular embolization have been reported. In these, six cases were treated by parent artery occlusion with coil and the subsequent three cases presented with ischemic complications. Only one case was treated by endosaccular embolization with GDC. To our knowledge, this is the second report of the distal AICA aneurysm treated by endosaccular embolization with GDC. Distal AICA aneurysms are briefly discussed while reviewing the literature.

[A case of cervical endodermal cyst].

A very rare case involving an endodermal cyst of the cervical spinal canal was documented. In 1999, a 28-year-old male presented with mild tetraplegia due to a traffic accident and consequently, he was admitted to another hospital. Magnetic resonance imaging (MRI) performed at that time demonstrated a cervical cord cyst. He was treated conservatively and as a result, complete resolution of symptoms was achieved. Five years later, he presented with progressive right hemiparesis and was referred to our institute. MRI at the time of admission exhibited an intradural extramedullary cystic lesion on the ventral side of the spinal cord at the C5-6 levels, which was characterized by low intensity on T1-weighted, and by high intensity on T2-weighted images. The cyst, which had increased in size, compressed the spinal cord remarkably backward. The anterior central vertebrectomy approach was performed. Subtotal resection of the cyst wall was conducted due to its tight partical adhesion to the spinal cord. The vertebral defect was reconstructed with an autogenous iliac graft. According to histological findings the cyst wall consisted of a single layer of columnar epithelial cells with secretory granules and immunohistochemical examination revealed that the cyst wall was positive for cytokeratin 7. Symptoms improved immediately. Subsequently, the patient was discharged with good performance status. Endodermal cysts are very rare developmental cysts derived from the embryonic endodermal layer. Moreover, these lesions are usually located intradurally in the cervical and upper dorsal spine ventral to the spinal cord. Total removal of the cyst is recommended if it is possible. However, total resection is often difficult due to adhesion of the cyst wall to the neural tissue so invasive resection should be avoided. In such cases, follow-up MRI is necessary in order to exclude recurrence of the remnant lesion.

[Preoperative embolization of metastatic spinal tumors].

The authors reviewed their clinical experience with preoperative embolization of metastatic spinal tumors. Between October 2000 and September 2003, 20 patients (13 men and 7 women; average age 68.3 years, range 44-82 years) underwent 24 spinal operations for 22 spinal metastatic tumors. Nineteen spinal operations (79%) were planned preoperative embolization with polyvinyl alcohol particles. In 3 cases, there was no tumor stain. Fifty percent of the C4-T2 lesions and 76% of the T3-L3 lesions were embolized preoperatively. The level of lesions determined which embolization procedure should be used. With C7-T2 or sacral lesions, feeding arteries were superselectively catheterized, then particles were injected via a microcatheter. With T3-L3 lesions, selective catheterization of the corresponding segmental arteries was performed. Particles were injected via 4 or 5Fr catheters. No complications were encountered during embolization. Embolizing from the origin of the segmental arteries is effective for reducing intraoperative blood loss because feeding vessels in the anterior part of the spinal body are able to be embolized. Preoperative embolization is not a very complicated procedure and careful catheterization can avoid complications. Based on tumor histology, size of the spinal body, depth of the operative field and operative approach, preoperative embolization can be performed with positive results.