• Journal of Korean Neurosurgical Society
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• v.61 no.2
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• pp.201-211
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• 2018

Objective : The purpose of this study was to analyze the variability of clopidogrel responses according to duration of a clopidogrel drug regimen after stent-assisted coil embolization (SAC), and to determine the correlation between the variability of clopidogrel responses and thromboembolic or hemorrhagic complications. Methods : A total of 47 patients who underwent SAC procedures to treat unruptured intracranial aneurysms were enrolled in the study. Preoperatively, patients received more than seven days of aspirin (100 mg) and clopidogrel (75 mg), daily. P2Y12 reaction unit (PRU) was checked with the VerifyNow test one day before the procedure (pre-PRU) and one month after the procedure (post-PRU). PRU variability was calculated as the difference between the initial response and the follow-up response. Patients were sorted into two groups based on their response to treatment : responsive and hypo-responsive. Results : PRU variability was significantly greater in the hypo-responsive group when compared to the responsive group (p=0.019). Pre-PRU and serum platelets counts were significantly correlated with PRU variation (p=0.005 and p=0.004, respectively). Although thromboembolic complication had no significant correlated factors, hemorrhagic complication was correlated with pre-PRU (p=0.033). Conclusion : In conclusion, variability of clopidogrel responses during clopidogrel medication was correlated to serum platelet counts and the initial clopidogrel response. Thromboembolic and hemorrhagic complications did not show correlation with the variability of clopidogrel response, or the clopidogrel response after one month of medication; however, hemorrhagic complication was associated with initial clopidogrel response. Therefore, it is recommended to test patients for an initial clopidogrel response only, as further tests would be insignificant.

• Journal of Korean Neurosurgical Society
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• v.59 no.1
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• pp.11-16
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• 2016

Objective : We conducted a retrospective cohort study to elucidate the natural course of unruptured intracranial aneurysms (UIAs) at a single institution. Methods : Data from patients diagnosed with UIA from March 2000 to May 2008 at our hospital were subjected to a retrospective analysis. The cumulative and annual aneurysm rupture rates were calculated. Additionally, risk factors associated with aneurysmal rupture were identified. Results : A total of 1339 aneurysms in 1006 patients met the inclusion criteria. During the follow-up period, 685 aneurysms were treated before rupture via either an open surgical or endovascular procedure. Six hundred fifty-four UIAs were identified and not repaired during the follow-up period. The mean UIA size was $4.5{\pm}3.2mm$, and 86.5% of the total UIAs had a largest dimension <7 mm. Among these UIAs, 18 ruptured at a median of 1.6 years (range : 27 days to 9.8 years) after day 0. The annual rupture risk during a 9-year follow-up was 1.00%. A multivariate Cox proportional hazards analysis revealed that the aneurysm size and a history of subarachnoid hemorrhage (SAH) were statistically significant risk factors for rupture. For an aneurysms smaller than 7 mm in the absence of a history of SAH, the annual rupture risk was 0.79%. Conclusion : In our study, the annual rupture risk for UIAs smaller than 7 mm in the absence of a history of SAH was higher than that of Western populations but similar to that of the Japanese population.

• Journal of Korean Neurosurgical Society
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• v.29 no.6
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• pp.786-793
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• 2000

Objectives : A clinical analysis was performed to provide management strategy and to improve management outcome of elderly patients with intracranial aneurysm. Patients and Methods : We reviewed medical records of 746 consecutive patients with intracranial aneurysm who were admitted from July 1991 to December 1996. They were divided into two age groups : elderly(120 patients aged 65 years or older) and non-elderly(626 patients aged 64 years or younger). We investigated the differences between the two groups in clinical characteristics, management outcome and surgical results. Results : Female(80.0%), internal carotid artery aneurysm(48.9%), poor clinical grade(Hunt and Hess Grade IV, V : 39.8%), postoperative subdural fluid collection(38.2%), and postoperative hydrocephalus(39.7%) were more frequent in the elderly patients. There were no significant differences in the incidence of hypertension, multiple aneurysm, unruptured aneurysm, rebleeding, delayed ischemic neurological deficits, postoperative hemorrhage, and low density on the postoperative brain CT scan. In some cases, surgical clipping of ruptured aneurysm could not be performed due to moribund state or refusal of surgery by the elderly patient's family. Both management outcome and surgical results in elderly aneurysm patients at 3 months after rupture were worse than those of the non-elderly group. The most common reason of unfavorable outcome was poor clinical grade in both groups, while serious medical illness causing unfavorable outcome was more common in the elderly group. Conclusion : Surgical treatment of a ruptured aneurysm should not be avoided in elderly patient solely on the basis of advanced age. If the patients are in good clinical grade, early aneurysm surgery followed by early ambulation should be recommended. Further improvements in outcome may be achieved by thorough knowledge of poor resilience of brain, CSF flow dynamics, and diminished cardiopulmonary reserve in elderly patients with intracranial aneurysm.

• Journal of Korean Neurosurgical Society
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• v.49 no.2
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• pp.97-101
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• 2011

Objective : It is technically difficult to treat wide-necked intracranial aneurysms by the endovascular method. Various tools and techniques have been introduced to overcome the related technical limitations. The purpose of this study was to evaluate the radiologic and clinical results of widenecked intracranial aneurysm treatment using the endovascular method. Methods : Fifteen aneurysms in 15 patients were treated by the endovascular method from October 2009 to August 2010. Seven patients presented with subarachnoid hemorrhage (SAH), seven patients had unruptured aneurysms, and one patient had an intracerebral hemorrhage and intraventricular hemorrhage due to an incompletely clipped aneurysm. The mean dome-to-neck ratio was 1.1 (range, 0.6-1.7) and the mean height-to-neck ratio was 1.1 (range, 0.6-2.0). We used double microcatheters instead of a stent or a balloon for the first trial. When we failed to make a stable coil frame with two coils, we used a stent-assisted technique. Results : All aneurysms were successfully embolized. Eleven aneurysms (73%) were embolized by the double microcatheter technique without stent insertion, and four aneurysms (27%) were treated by stent-assisted coil embolization. One case had subclinical procedure-related intraoperative hemorrhage. Another case had procedure-related thromboembolism in the left distal anterior cerebral artery. During the follow-up period, one patient (7%) had a recanalized aneurysmal neck 12 months after coil embolization. The recurrent aneurysm was treated by stent-assisted coil embolization. Conclusion : We successfully treated 15 wide-necked intracranial aneurysms by the endovascular method. More clinical data with longer follow-up periods are needed to establish the use of endovascular treatment for wide-necked aneurysm.

• Journal of Korean Neurosurgical Society
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• v.60 no.2
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• pp.146-154
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• 2017

Objective : The semi-jailing technique (SJT) provides stent-assisted remodeling of the aneurysm neck during coil embolization without grasping the coil delivery microcatheter. We retrospectively evaluated the efficacy and safety of SJT using a Neuroform3 stent for coiling of wide-necked intracranial aneurysms. Methods : We collected the clinical and radiological data between January 2009 and June 2015 of the wide-necked aneurysms treated with SJT using a Neuroform3 stent. Results : SJT using a Neuroform3 stent was attempted in 70 wide-necked aneurysms (68 patients). There were 56 unruptured and 14 ruptured aneurysms. The size of aneurysm ranged from 1.7 to 28.1 mm (mean 6.1 mm). The immediate angiographic results were complete occlusion in 55 aneurysms (78.6%), neck remnant in 7 (10.0%), and aneurysm remnant in 8 (11.4%). Overall, periprocedural complications occurred in 13 patients (19.1%), including asymptomatic thromboembolism in 7 (10.3%), symptomatic thromboembolism in 4 (5.9%), and symptomatic hemorrhagic complications in 2 (2.9%). Conventional angiography follow-up was obtained in 55 (78.6%) of 70 aneurysms (mean, 10.9 months). The result showed progressive occlusion in 7 aneurysms (12.7%) and recanalization in 1 aneurysm (1.8%). At the end of the observation period (mean, 17.5 months), all 54 patients without subarachnoid hemorrhage showed excellent clinical outcomes (modified Rankin Scale [mRS] 0), except two (mRS 1 or 2) and seven of 14 patients with subarachnoid hemorrhage remained symptom-free (mRS 0). Conclusion : In this report of 70 aneurysms, SJT using a Neuroform3 stent for coiling of wide-necked intracranial aneurysms showed good technical safety, as well as favorable clinical and angiographic outcomes.

• Journal of Korean Neurosurgical Society
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• v.54 no.2
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• pp.86-92
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• 2013

Objective : Surgical results for anterior choroidal artery (AChA) aneurysms have previously been reported as unsatisfactory due to inadvertent occlusion of the AChA, while the low incidence of AChA aneurysms hampers the accumulation of surgical experience. The authors reviewed their related surgical experience to document the ischemic complications and surgical outcomes. Methods : Identification of the AChA at its origin by rigorous visual scrutiny, careful microdissection, and meticulous clip placement to avoid the AChA origin are all crucial surgical maneuvers. A retrospective review of a surgical series of 62 consecutive cases of an AChA aneurysm between 2004 and 2012 was performed. Results : All patients, except for five (8.1%) with a small residual neck, showed complete aneurysm obliteration in postoperative angiographic evaluations. There was no incidence of procedure-related permanent AChA syndrome or oculomotor nerve palsy, while three (4.8%) patients suffered from transient AChA syndrome. The clinical outcomes [the 3-month modified Rankin Scale (mRS)] of the patients were related to their preoperative World Federation of Neurologic Surgeons (WFNS) grade. As regards the 3-month mRS, significant differences were found between patients with an unruptured aneurysm (WFNS grade 0; n=20), good-grade subarachnoid hemorrhage (WFNS grade 1-3; n=30), and poor-grade subarachnoid hemorrhage (WFNS grade 4-5; n=4). Conclusion : In surgical treatment of AChA aneurysms, a risk of AChA insufficiency can be minimized by taking every precaution to preserve the AChA patency and intraoperative monitoring. In addition, the surgical outcome is primarily determined by the preoperative clinical state.

• Journal of Korean Neurosurgical Society
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• v.61 no.2
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• pp.212-218
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• 2018

Objective : Surgical clipping of the cerebral aenurysm is considered as a standard therapy with endovascular coil embolization. The surgical clipping is known to be superior to the endovascular coil embolization in terms of recurrent rate. However, a recurrent aneurysm which is initially treated by surgical clipping is difficult to handle. The purpose of this study was to research the management of the recurrent cerebral aneurysm after a surgical clipping and how to overcome them. Methods : From January 1996 to December 2015, medical records and radiologic findings of 14 patients with recurrent aneurysm after surgical clipping were reviewed retrospectively. Detailed case-by-case analysis was performed based on preoperative, postoperative and follow-up radiologic examinations and operative findings. All clinical variables including age, sex, aneurysm size and location, type and number of applied clips, prognosis, and time to recurrence are evaluated. All patients are classified by causes of the recurrence. Possible risk factors that could contribute to those causes and overcoming ways are comprehensively discussed. Results : All recurrent aneurysms after surgical clipping were 14 of 2364 (0.5%). Three cases were males and 11 cases were females. Mean age was 52.3. At first treatment, nine cases were ruptured aneurysms, four cases were unruptured aneurysms, and one case was unknown. Locations of recurrent aneurysm were determined; anterior communicating artery (A-com) (n=7), posterior communicating artery (P-com) (n=3), middle cerebral artery (n=2), anterior cerebral artery (n=1) and basilar artery (n=1). As treatment of the recurrence, 11 cases were treated by surgical clipping and three cases were treated by endovascular coil embolization. Three cases of all 14 cases occurred in a month after the initial treatment. Eleven cases occurred after a longer interval, and three of them occurred after 15 years. By analyzing radiographs and operative findings, several main causes of the recurrent cerebral aneurysm were found. One case was incomplete clipping, five cases were clip slippage, and eight cases were fragility of vessel wall near the clip edge. Conclusion : This study revealed main causes of the recurrent aneurysm and contributing risk factors to be controlled. To manage those risk factors and ultimately prevent the recurrent aneurysm, neurosurgeons have to be careful in the technical aspect during surgery for a complete clipping without a slippage. Even in a perfect surgery, an aneurysm may recur at the clip site due to a hemodynamic change over years. Therefore, all patients must be followed up by imaging for a long period of time.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup2
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• pp.203-210
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• 2001

Objective : Paraclinoidal aneurysms termed that aneurysms arising from proximal internal carotid artery(ICA) between the site of emergence of the carotid artery from roof of the cavernous sinus and origin of the posterior communicating artery(PCoA). These aneurysms pose conceptual and technical surgical problems with regard to acquisition of proximal control and safe intracranial exposure. The efficiency of surgical technique according to the location of paraclinoidal aneurysm was studied for minimal exposure. Materials and Methods : Over the past four years, the authors treated surgically 171 cases of cerebral aneurysm, among them ten patients were paraclinoidal aneurysms with two patients unruptured aneurysms. Mean age was 47 years old, and all patients were female. Three patients were proximal posterior carotid artery wall aneurysms(one large, one giant), four patients carotid-ophthalmic artery aneurysms and three patients superior hypophyseal artery aneurysms. Results : There could be done clip in all cases, there were no deaths and no complication. And no patient developed sustained neurological deficits including visual function except hydrocephalus in one case. Four patients complained of visual disturbance but two patients had recovery after postoperation and two patient were not longer to bad. Conclusion : Our recent experience suggests that preoperative scrutiny of diagnostic angiography allows classification of all paraclinoidal aneurysms regardless of size and surgical technique which this classification has focused on operative approaches unique to each aneurysm projection was helpful to improve the operative outcome with good visual function and to shorten the operative time.

• Journal of Korean Neurosurgical Society
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• v.39 no.3
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• pp.192-197
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• 2006

Objective : Eleven patients treated with posterior cerebral artery[PCA] aneurysm during 6.3-years period are retrospectively reviewed to determine treatment outcome. Methods : Eleven patients with PCA aneurysm were treated from January 1998 to May 2004. Their medical records and radiologic studies were reviewed retrospectively. The records of these patients were analysed with particular reference to their demographic details, mode of presentation, and treatment outcome. Results : Of the 11 patients, 8 patients presented with symptoms related aneurysmal bleeding. Three patients had unruptured PCA aneurysms. Open or endovascular surgery was performed in 9 patients; None of these patients exhibited a third nerve palsy, visual field deficit, or hemiparesis at the time of presentation. Postoperatively, 2 made a good recovery, 2 had a moderate disability because of cerebral infarction after surgery, and 5 had a severe disability because of cerebral infarction after surgery. Of 2 conservatively treated patients, 1 was doing well but the other died as a result of brain swelling. Conclusion : The treatment of the PCA aneurysms is difficult regardless of the aneurysmal size, site, and treatment modality. All reasonable treatment to reduce the risk of associated morbidity should be considered.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup1
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• pp.73-78
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• 2001

Objective : Intraoperative rupture of an intracranial aneurysm can interrupt a microsurgical procedure and jeopardize the patient's chance to favorable outcome. The purpose of this study was to analyse and evaluate intraoperative aneurysmal rupture and render ideal prevention and management to intraoperative rupture. Patients and Methods : The authors retrospectively analysed the results of 609 patients who underwent cerebral aneurysm surgery from January 1991 to December 2000. Results : 1) Intraoperative aneurysmal rupture occurred in 73 of 609 consecutive aneurysm surgery, so the incidence was about 12.0% and it was relatively lower than other reports. 2) Aneurysms arising from anterior communicating artery appeared more prone to intraoperative rupture. 3) The size of aneurysm and timing of operation didn't influence intraoperative aneurysmal rupture and temporary clipping didn't reduce the incidence of intraoperative aneurysmal rupture. 4) Intraoperative aneurysmal rupture occured during three specific periods : (1) dissection stage in 61%, (2) clip application stage in 29 %, (3) predissection stage in 10%. 5) In the patients with intraoperative aneurysmal rupture, surgical outcome was relatively good and there was no significant difference in outcome compared with unruptured group. Conclusion : Our suggestion for prevention methods of intraoperative aneurysmal rupture are as follows : 1) minimal brain retraction, 2) sharp and careful aneurysmal neck dissection, 3) gentle clipping with proper clip selection etc. Management methods after intraoperative aneurysmal rupture are as follows : 1) strong aspiration of bleeding point, 2) rapid application of temporary and/or tentative clip, 3) following rapid dissection of neck and proper clip application, 4) use of encircling clip etc.