• Journal of Korean Neurosurgical Society
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• 제64권4호
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• pp.665-670
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• 2021

Symptomatic cerebral vasospasm (CVS) and delayed ischemic neurologic deficit (DIND) after unruptured aneurysm surgery are extremely rare. Its onset timing is variable, and its mechanisms are unclear. We report two cases of CVS with DIND after unruptured aneurysm surgery and review the literature regarding potential mechanisms. The first case is a 51-year-old woman with non-hemorrhagic vasospasm after unruptured left anterior communicating artery aneurysm surgery. She presented with delayed vasospasm on postoperative day 14. The second case is a 45-year-old woman who suffered from oculomotor nerve palsy caused by an unruptured posterior communicatig artery (PCoA) aneurysm. DIND with non-hemorrhagic vasospasm developed on postoperative day 12. To our knowledge, this is the first report of symptomatic CVS with oculomotor nerve palsy following unruptured PCoA aneurysm surgery. CVS with DIND after unruptured aneurysm surgery is very rare and can be triggered by multiple mechanisms, such as hemorrhage, mechanical stress to the arterial wall, or the trigemino-cerebrovascular system. For unruptured aneurysm surgery, although it is rare, careful observation and treatments can be needed for postoperative CVS with DIND.

• Journal of Korean Neurosurgical Society
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• 제61권6호
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• pp.689-699
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• 2018

Objective : The goal of this study was to compare several parameters, including wall shear stress (WSS) and flow pattern, between unruptured and ruptured anterior communicating artery (ACoA) aneurysms using patient-specific aneurysm geometry. Methods : In total, 18 unruptured and 24 ruptured aneurysms were analyzed using computational fluid dynamics (CFD) models. Minimal, average, and maximal wall shear stress were calculated based on CFD simulations. Aneurysm height, ostium diameter, aspect ratio, and area of aneurysm were measured. Aneurysms were classified according to flow complexity (simple or complex) and inflow jet (concentrated or diffused). Statistical analyses were performed to ascertain differences between the aneurysm groups. Results : Average wall shear stress of the ruptured group was greater than that of the unruptured group (9.42% for aneurysm and 10.38% for ostium). The average area of ruptured aneurysms was 31.22% larger than unruptured aneurysms. Simple flow was observed in 14 of 18 (78%) unruptured aneurysms, while all ruptured aneurysms had complex flow (p<0.001). Ruptured aneurysms were more likely to have a concentrated inflow jet (63%), while unruptured aneurysms predominantly had a diffused inflow jet (83%, p=0.004). Conclusion : Ruptured aneurysms tended to have a larger geometric size and greater WSS compared to unruptured aneurysms, but the difference was not statistically significant. Flow complexity and inflow jet were significantly different between unruptured and ruptured ACoA aneurysms.

• Journal of Korean Neurosurgical Society
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• 제40권2호
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• pp.131-134
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• 2006

The cerebral vasospasm after clipping surgery of unruptured aneurysm is uncommon. A 44-year-old man with unruptured left middle cerebral artery[MCA] aneurysm had clipping surgery. From the third postoperative day, he presented with drowsy mentality, dysphasia and right hemiparesis. Computed tomographic scans showed low density area in frontotemporal lobe and midline shift. Transfemoral cerebral angiography revealed severe vasospasm in supraclinoid internal carotid artery, anterior cerebral artery, and MCA on the operative side. We performed left frontotemporoparietal craniectomy and hypertensive-hypervolemic therapy. He recovered without neurological deficits but for dysphasia. Neurosurgeon should be alert to the possibility of vasospasm after clipping surgery even in case of unruptured cerebral aneurysm.

• Journal of Korean Neurosurgical Society
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• 제42권3호
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• pp.235-237
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• 2007

We describe a case of an unruptured basilar top aneurysm that was associated with early rupture after incomplete coiling. A 62-year-old woman with a history of several small infarctions has undergone coiling of unruptured basilar top aneurysm. Two weeks after initial coiling the patient presented with Hunt and Hess grade IV subarachnoid hemorrhage consistent with a ruptured basilar top aneurysm. Repeat angiography revealed a rupture of recanalized basilar top aneurysm. Second embolization with additional coils resulted in complete occlusion. However, her neurological status was not improved afterward and she was transferred to department of rehabilitation one month after hemorrhage with comatous state. To our knowledge, this is the first case of fatal early rupture after coiling of unruptured aneurysm. It has been speculated that coiling could cause injury to aneurysmal wall and facilitate rupture.

• Journal of Korean Neurosurgical Society
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• 제29권3호
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• pp.330-335
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• 2000

Objective : The purpose of this report is to assess the morbidity and mortality associated with clipping of intracranial unruptured aneurysms. Methods : At the authors' institution between May 1989 and December 1998, a total of 128 unruptured aneurysms in 110 patients were treated with surgical clippings. The medical records and neuroimaging studies of the patients were reviewed retrospectively. Results : The main locations of the aneurysms were : middle cerebral artery 31%, internal carotid-posterior communicating artery 28%, anterior communicating artery 16%, paraclinoid 6.5%, internal carotid-anterior choroidal artery 7%, posterior circulation 7%. Forty three percent of the aneurysms were symptomatic and 57% asymptomatic. The overall outcome of the surgery was : Glasgow outcome scale(GOS) I 86%, GOS II 6%, GOS III 4.3%, GOS IV 0% and GOS V(death) 3.5%. The operative risk is higher for large to giant aneurysms, and for aneurysms in posterior circulations. Patients with non-giant aneurysm in anterior circulation showed no mortality, but morbidity of 8.2%, and in posterior circulation : 25% of mortality and 75% of morbidity. Patients with giant anterior circulation aneurysm have 22% of mortality and 22% of morbidity. For patients with giant posterior circulation aneurysm, mortality and morbidity were 25% and 25%, respectively. The postoperative deaths were related to occlusion of the major parent artery in 3 cases(75%). The postoperative morbidity was related to occlusion of artery(9/13), intraoperative rupture(3/13), and cranial nerve injury(1/13). Conclusion : This report documents 3.5% mortality and 13% of morbidity in the clipping surgery for unruptured intracranial aneurysms, and the relatively low risk of surgical clipping in non-giant and those located in anterior circulation. The natural history, especially risk of bleeding, of the unruptured intracranial aneurysms is still controversial. However, with respect to surgical results, unruptured non-giant aneurysm located in anterior circulation should be operated in patients with low risk.

• Journal of Korean Neurosurgical Society
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• 제52권3호
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• pp.243-245
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• 2012

It is well known that spontaneous thrombosis in giant cerebral aneurysm is common. However, spontaneous obliteration of a non-giant and unruptured cerebral aneurysm has been reported to be rare and its pathogenic mechanism is not clear. We describe a case with rare vascular phenomenon and review the relevant literatures.

• Journal of Korean Neurosurgical Society
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• 제50권1호
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• pp.45-47
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• 2011

Abnormal contrast enhancement on brain computed tomography (CT) scan after diagnostic or interventional angiography is not rare, and has known to be induced by temporary blood-brain barrier (BBB) disruption from contrast media. Furthermore, it has been regarded as clinically subtle, but reported to have no symptom or mild transient symptoms. However, we recently experienced two cases of serious BBB disruption during the acute period after coiling of an unruptured intracranial aneurysm. One patient presented with an unruptured paraclinoid internal carotid artery (ICA) aneurysm on the right and the other with an unruptured right supraclinoid ICA aneurysm. Both patients showed similar findings on immediate postembolization CT scan and clinical courses after coiling. Typical radiological, clinical characteristics of BBB disruption were described. In addition, the role of immediate postembolization CT scan are also discussed.

• Journal of Korean Neurosurgical Society
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• 제59권6호
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• pp.564-569
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• 2016

Objective : This study used the intradural procedural time to assess the overall technical difficulty involved in surgically clipping an unruptured middle cerebral artery (MCA) aneurysm via a pterional or superciliary approach. The clinical and radiological variables affecting the intradural procedural time were investigated, and the intradural procedural time compared between a superciliary keyhole approach and a pterional approach. Methods : During a 5.5-year period, patients with a single MCA aneurysm were enrolled in this retrospective study. The selection criteria for a superciliary keyhole approach included : 1) maximum diameter of the unruptured MCA aneurysm <15 mm, 2) neck diameter of the MCA aneurysm <10 mm, and 3) aneurysm location involving the sphenoidal or horizontal segment of MCA (M1) segment and MCA bifurcation, excluding aneurysms distal to the MCA genu. Meanwhile, the control comparison group included patients with the same selection criteria as for a superciliary approach, yet who preferred a pterional approach to avoid a postoperative facial wound or due to preoperative skin trouble in the supraorbital area. To determine the variables affecting the intradural procedural time, a multiple regression analysis was performed using such data as the patient age and gender, maximum aneurysm diameter, aneurysm neck diameter, and length of the pre-aneurysm M1 segment. In addition, the intradural procedural times were compared between the superciliary and pterional patient groups, along with the other variables. Results : A total of 160 patients underwent a superciliary (n=124) or pterional (n=36) approach for an unruptured MCA aneurysm. In the multiple regression analysis, an increase in the diameter of the aneurysm neck (p<0.001) was identified as a statistically significant factor increasing the intradural procedural time. A Pearson correlation analysis also showed a positive correlation (r=0.340) between the neck diameter and the intradural procedural time. When comparing the superciliary and pterional groups, no statistically significant between-group difference was found in terms of the intradural procedural time reflecting the technical difficulty (mean${\pm}$standard deviation : $29.8{\pm}13.0min$ versus $27.7{\pm}9.6min$). Conclusion : A superciliary keyhole approach can be a useful alternative to a pterional approach for an unruptured MCA aneurysm with a maximum diameter <15 mm and neck diameter <10 mm, representing no more of a technical challenge. For both surgical approaches, the technical difficulty increases along with the neck diameter of the MCA aneurysm.

• Journal of Korean Neurosurgical Society
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• 제52권4호
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• pp.306-311
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• 2012

Objective : A superciliary keyhole approach is an attractive, minimally invasive surgical technique, yet the procedure is limited due to a small cranial opening. Nonetheless, an unruptured supraclinoid internal carotid artery (ICA) aneurysm can be an optimal surgical target of a superciliary approach as it is located in the center of the surgical view and field. Therefore, this study evaluated the feasibility and surgical outcomes of a superciliary keyhole approach for unruptured ICA aneurysms. Methods : The authors report on a consecutive series of patients who underwent a superciliary approach for clipping unruptured ICA aneurysms between January 2007 and February 2012. The data were compared with a historical control group who underwent a pterional approach between January 2003 and December 2006. Results : In the superciliary group, a total of 71 aneurysms were successfully clipped without a residual sac in 70 patients with a mean age of 57 years (range, 37-75 years). The maximum diameter of the aneurysms ranged from 4 mm to 14 mm (mean${\pm}$standard deviation, $6.6{\pm}2.3$ mm). No direct mortality or permanent morbidity was related to the surgery. The superciliary approach demonstrated statistically significant advantages over the pterional approach, including a shorter operative duration (mean, 100 min), no intraoperative blood transfusions, and no postoperative epidural hemorrhages. Conclusion : A superciliary keyhole approach provides a sufficient surgical corridor to clip most unruptured supraclinoid ICA aneurysms in a minimally invasive manner.

• Journal of Korean Neurosurgical Society
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• 제64권2호
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• pp.189-197
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• 2021

Objective : This study aims to investigate the relationship between aneurysm wall enhancement and clinical rupture risks based on the magnetic resonance vessel wall imaging (MR-VWI) quantitative methods. Methods : One hundred and eight patients with 127 unruptured aneurysms were prospectively enrolled from Feburary 2016 to October 2017. Aneurysms were divided into high risk (≥10) and intermediate-low risk group (<10) according to the PHASES (Population, Hypertension, Age, Size of aneurysm, Earlier SAH history from another aneurysm, Site of aneurysm) scores. Clinical risk factors, aneurysm morphology, and wall enhancement index (WEI) calculated using 3D MR-VWI were analyzed and compared. Results : In comparison of high-risk and intermediated-low risk groups, univariate analysis showed that neck width (4.5±3.3 mm vs. 3.4±1.7 mm, p=0.002), the presence of wall enhancement (100.0% vs. 62.9%, p<0.001), and WEI (1.6±0.6 vs. 0.8±0.8, p<0.001) were significantly associated with high rupture risk. Multivariate regression analysis revealed that WEI was the most important factor in predicting high rupture risk (odds ratio, 2.6; 95% confidence interval, 1.4-4.9; p=0.002). The receiver operating characteristic (ROC) curve analysis can efficiently differentiate higher risk aneurysms (area under the curve, 0.780; p<0.001) which have a reliable WEI cutoff value (1.04; sensitivity, 0.833; specificity, 0.67) predictive of high rupture risk. Conclusion : Aneurysms with higher rupture risk based on PHASES score demonstrate increased neck width, wall enhancement, and the enhancement intensity. Higher WEI in unruptured aneurysms has a predictive value for increased rupture risk.