Giant fusiform aneurysms are characterized by tortuosity, elongation, distention, and partial thrombosis, and are most frequently found in the vertebrobasilar circulation. Surgical removal of these aneurysms is the treatment of choice for such lesions because they often develop mass signs. We report 14 surgically treated cases that were classified into so-called thrombosed aneurysms in the posterior fossa (VA involved: 9, VA-BA involved: 3, BA involved: 2). Four cases out of 9 VA-involved cases were treated with aneurysmal trapping and aneurysmectomy after OA-PICA anastomosis. The other 5 cases were trapped and aneurysmectomy was performed because of no involvement of PICA flow. Seven out of 9 cases showed very excellent surgical outcomes instead of preoperative pyramidal signs. However, 5 cases involving VA-BA or BA were treated with high flow bypass (VA-RA-PCA bypass), and Hunterian ligation showed very poor surgical outcomes. Only 1 case recovered well after surgery and resumed social activity. The unsatisfactory results were considered to be caused by high flow bypass flew up thrombus induced within the blind aneurysm sac into the perforators, resulting in catastrophic central pontine infarction. The enhanced reversed flow through the bypass caused the already thrombosed aneurysms to grow. We analyze the operative results and discuss the pathogenesis.

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Giant aneurysms have a dismal natural history, thus necessitating early management. These pose a great challenge to the vascular neurosurgeon. The complexity of their anatomy, parent vessels or branches and perforators warrants additional measures for maintaining distal perfusion. Here we try to define the minimally invasive management of these aneurysms. This study compares reconstruction and bypass.
This study covers 40 large and 5 giant cases of aneurysms treated in our institute. Giant aneurysms are those with a dome diameter 25 mm or more. 3D CT scan and DSA were the primary investigative procedures, and 3D CT scan was especially useful in thrombosed aneurysms. Aneurysms that had involved a major portion of the parent wall were reconstructed, thus avoiding bypass.
Based on our experience, not only basic technique of trapping and evacuation and clipping of the aneurysm neck but also reconstruction of the artery bearing the aneurysm is vital for good postoperative results. Different clipping methods are also used to reconstruct the parent artery. Bypass techniques are also gaining importance in the management of giant aneurysms in difficult cases. However, we feel that bypass procedures are too extensive and are associated with attendant complications. Acute graft occlusion is one of the commonest complications. Aneurysmal rupture is one more complication of bypass procedures. Prolonged occlusion can also cause neurological deficits.
Considering the difficulties with bypass and our experience in parent vessel reconstruction with multiple clipping, we feel bypass should be considered only in exceptional cases.

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We evaluate the efficacy of the coil embolization for tiny ruptured anterior communicating artery (ACoA) aneurysms. Of 21 ruptured ACoA aneurysms with a maximum diameter of 3 mm, coil embolization was successfully carried out in 20 (95%) as the first treatment option. Complete occlusion was achieved in 17 of 20 patients and nearly complete occlusion was realized in 3. There were no treatment-related complications. Seventeen of 20 patients were followed up angiographically for a mean 39.7 months (range 6-72 months), and none of them demonstrated reopening of aneurysm that required additional treatment. Even in tiny ruptured ACoA aneurysms, coil embolization can be a safe and feasible treatment with sophisticated techniques.

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We analyzed 22 patients with hemispheric infarction that underwent decompressive hemicraniectomy with duroplasty (DHCD) between October 2003 and September 2007. The surgery was indicated when the level of consciousness deteriorated, anisocoria appeared, or the midline shift on computed tomography worsened. These patients comprised 14 males and 10 females aged 58 to 90 years old (mean 71.5 years old). At 6 months follow-up, 6 cases (27%) had a good outcome (Barthel Index (BI)≥15), and 16 cases (73%) had a poor outcome (BI<15). The mortality rate was 31.8% (7 cases), and 3 patients (13.6%) died of cerebral herniation. The results showed that DHCD can effectively control intractable intracranial hypertension due to hemispheric infarction, even in elderly patients.

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Our institution utilizes an integrated operating room in which both microneurosurgery and endovascular neurosurgery can be performed. We report our early experience of the use of this operating room. Between April 2007 and March 2008, we performed open surgery in 8 cases for cerebrovascular pathologies, 7 of which were aneurysms and 1 of which was an AVM. Two of the aneurysms were paraclinoid large aneurysms. One was a ruptured multiple mycotic aneurysm and the other was an MC bifurcation aneurysm with severe M1 stenosis. Two cases of the aneurysms were coil embolized first, and then converted to open surgery. One AVM case was embolized first and then resected after craniotomy in 1 session.
We discuss usefullness of this multifunctional integrated operating room.

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We report 6 cases with symptomatic intracranial vertebral artery stenosis treated with percutaneous transluminal angioplasty (PTA).
Five of 6 cases had no contralateral vertebral artery (VA) and only 1 had hypoplastic contralateral VA. PTA was urgently performed in 3 cases presenting with progressive infarction. We used a balloon-expandable coronary stent against vertebral artery dissection subsequently after PTA in 1 case. No complications occurred during the procedure in any of the cases. Five cases were discharged from our hospital and could live independently. In 1 case in which PTA was urgently performed, disturbance of consciousness and tetraparesis remained.
The presence of a high-grade vertebral artery stenosis and a contralateral vertebral artery hypoplasia or occlusion can induce a progressive infarction in the early stage, so immediate revascularization should be considered in these cases.

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Intracranial vertebral artery (VA) dissecting aneurysms are commonly treated with endovascular parent artery occlusion. However, this procedure cannot be applied to patients with aplastic/hypoplastic contralateral VA or with posterior inferior cerebellar artery (PICA) involved in the dissecting segment. Recently, endovascular treatment using stents for VA dissecting aneurysms has been reported. In this study, we investigated the safety, efficacy, and optimal application of this treatment.
Thirteen patients were treated using stents to preserve the patency of the VA, PICA, and anterior spinal artery (ASA). In 6 patients, PICA or ASA was involved in the dissecting segment. Seven patients presented with subarachnoid hemorrhage (SAH), 4 with ischemic symptoms, 1 with headache without SAH, and 1 with incidental discovery. Eleven patients were treated with stent-assisted coil embolization and 2 with stenting only.
Stents were successfully deployed in all patients. Of the 11 patients treated with stent-assisted coiling, complete obliteration of the aneurysm was achieved in 5 patients and residual dome filling was present in 5. In the remaining patient, aneurysm rupture occurred during the insertion of the coils, and therefore parent artery occlusion was performed. In 2 patients treated with stenting only, complete obliteration was confirmed by follow-up angiography. Growth of the aneurysmal dilatation occurred in 1 patient, but subsequent SAH was not observed in any patient.
Endovascular treatment using stents and coils appears safe and effective, and provides an effective alternative to treating patients with aplasia/hypoplasia of the contralateral VA and some patients with involvement of the origin of PICA or ASA in the dissecting segment.

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Meticulous clipping techniques are essential to obtain good results. Recently, the introduction of intravascular surgery for cerebral aneurysms has decreased the number of the direct clipping surgeries. And the increasing number of the lawsuits against doctors further discourages young surgeons from attempting clipping. As a result, young neurosurgeons, have less experience performing clipping. Therefore, we must learn clipping techniques from expert neurosurgeons under the limitation of having fewer opportunities to perform clipping surgery. In this paper, I present my experiences and discuss ways to obtain techniques for clipping surgery.
I performed surgical clipping in 19 cases, 12 unruptured and 7 ruptured aneurysms, 7 males and 12 females aged from 36 to 79 years old (mean 61.9 years). Postoperatively, there were no symptomatic complications, but there were 2 asymptomatic infarctions that were revealed on CT scan. Intraoperative premature rupture occurred in 1 patient with a ruptured aneurysm.
Techniques of manipulation with micro-forceps, suction and spatula are required for successful clipping. Off-the-job training of dissecting chicken wing arteries and rat abdominal aortas and vena cavas is useful. Moreover, actual experiences of surgical operations are essential. Surgical experiences raise the motivation of young neurosurgeons and encourage them to train more. We believe that this benign cycle contributes to meticulous surgical skills.

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We experienced 5 cases of nonbranching site aneurysms arising from the internal carotid artery system in the past 5 years. Two cases were successfully treated with neck clipping and 2 cases were treated with trapping. Wrapping by gauze and fibrin glue was used in 1 unruptured case. The outcome was good in all cases (mRS 0-2).
However, non-branching site aneurysms have fragile walls, the neck is not clearly defined and postoperative rebleeding can easily occur. We believe the sacrifice of a normal parent artery is necessary to prevent re-bleeding. For this reason, we believe interception of the parent artery should always be considered to prevent postoperative rebleeding.
When parent artery interception is of concern regarding postoperative ischemic events, a high-flow EC-IC bypass may be needed. On the other hand, the issue of separation of the neck is possible at all sides and the possibility of clipping strangling part of the parent artery also exists.

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We present 2 patients in whom basal interhemispheric (BIH) approaches were applied to surgically address anterior communicating artery aneurysms (AcomAn) after initial surgery via pterional approaches that resulted in incomplete clipping. In both patients, the initial clips were successfully removed with use of vario clip appliers followed by complete neck clipping. The first case was a 55-year-old man with subarachnoid hemorrhage (SAH) who arrived in poor cardiopulmonary condition. Angiographic evidence of extravasation of the contrast media led us to immediately surgically intervene via the dominant side of the anterior cerebral artery. However, complete neck clipping was abandoned due to marked brain swelling, and only aneurysm dome clipping was achieved. Thirty-eight days later, a second surgery was performed using the BIH approach. The second case was a 66-year-old woman with SAH caused by ruptured AcomAn associated with the median artery of the corpus callosum (MACC). A residual neck remnant grew gradually. After failed coil embolization, she had a second surgical intervention via the BIH approach 18 months after the initial surgery. Previous clips were removed in both patients and the coil was also removed in the second one. The BIH approach provides a wider surgical view and working space. We report technical tips to remove previously placed clips via different surgical approaches.

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We successfully performed carotid artery stent placement (CAS) in 3 patients with cervical carotid artery stenosis presenting with progressing stroke. In our presented cases, we used intravascular ultrasonographic virtual histology (IVUS-VH) to evaluate carotid plaque and continuous monitoring of regional cerebral oxygenation by near-infrared spectroscopy to detect early hemodynamic complications. These techniques significantly helped to improve neurological outcome after CAS in patients with progressing stroke. In Case 1, an 80-year-old female presented with progressing right hemiparesis due to severe stenosis of the cervical portion of the left carotid artery. IVUS-VH revealed the plaque as mainly fibrous and partially necrotic and fibrolipidic, and under distal protection, CAS was successfully performed. In Case 2, a 70-year-old male presented with repeated transient loss of consciousness. 3D-CT angiography demonstrated severe stenosis of the cervical portion of the right carotid artery, and under the distal protection, CAS was conducted. During placement of the carotid stent, near infrared spectroscopy revealed a marked change in cerebral oximetry. His blood pressure was carefully controlled for 3 days to avoid hyperperfusion syndrome. In Case 3, a comatose 76-year-old male was admitted to our hospital with right-sided hemiparesis. He had suffered several transient ischemic attacks 6 months previously. Intravenous rt-PA therapy was performed, and his symptoms improved rapidly. 3D-CT angiography demonstrated severe stenosis of the right cervical carotid artery with dense calcified plaque. However, IVUS-VH revealed the plaque as mainly fibrous with partial calcification, and CAS was successfully performed.

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