• Journal of Korean Neurosurgical Society
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• v.45 no.1
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• pp.11-15
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• 2009

Objective : The aim of study was to review our patient population to determine whether there is a critical aneurysm size at which the incidence of rupture increases and whether there is a correlation between aneurysm size and location. Methods : We reviewed charts and radiological findings (computed tomography (CT) scans, angiograms, CT angiography, magnetic resonance angiography) for all patients operated on for intracranial aneurysms in our hospital between September 2002 and May 2004. Of the 336 aneurysms that were reviewed, measurements were obtained from angiograms for 239 ruptured aneurysms by a neuroradiologist at the time of diagnosis in our hospital. Results : There were 115 male and 221 female patients assessed in this study. The locations of aneurysms were the middle cerebral artery (MCA, 61), anterior communicating artery (ACoA, 66), posterior communicating artery (PCoA, 52), the top of the basilar artery (15), internal carotid artery (ICA) including the cavernous portion (13), anterior choroidal artery (AChA, 7), A1 segment of the anterior cerebral artery (3), A2 segment of the anterior cerebral artery (11), posterior inferior cerebellar artery (PICA, 8), superior cerebellar artery (SCA, 2), P2 segment of the posterior cerebral artery (1), and the vertebral artery (2). The mean diameter of aneurysms was $5.47{\pm}2.536\;mm$ in anterior cerebral artery (ACA), $6.84{\pm}3.941\;mm$ in ICA, $7.09{\pm}3.652\;mm$ in MCA and $6.21{\pm}3.697\;mm$ in vertebrobasilar artery. The ACA aneurysms were smaller than the MCA aneurysms. Aneurysms less than 6 mm in diameter included 37 (60.65%) in patients with aneurysms in the MCA, 43 (65.15%) in patients with aneurysms in the ACoA and 29 (55.76%) in patients with aneurysms in the PCoA. Conclusion : Ruptured aneurysms in the ACA were smaller than those in the MCA. The most prevalent aneurysm size was 3-6 mm in the MCA (55.73%), 3-6 mm in the ACoA (57.57%) and 4-6 mm in the PCoA (42.30%). The more prevalent size of the aneurysm to treat may differ in accordance with the location of the aneurysm.

• Journal of Korean Neurosurgical Society
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• v.45 no.4
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• pp.260-263
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• 2009

Internal carotid artery (ICA) trapping can be used for treating intracranial giant aneurysm, blood blister-like aneurysms and ICA rupture during the surgery. We present a novel ICA trapping technique which can be used with insufficient collaterals flow via anterior communicating artery (AcoA) and posterior communicating artery (PcoA). A patient was admitted with severe headache and the cerebral angiography demonstrated a typical blood blister-like aneurysm at the contralateral side of PcoA. For trapping the aneurysm, the first clip was placed at the ICA just proximal to the aneurysm whereas the distal clip was placed obliquely proximal to the origin of the PcoA to preserve blood flow from the PcoA to the distal ICA. The patient was completely recovered with good collaterals filling to the right ICA territories via AcoA and PcoA. This technique may be an effective treatment option for trapping the aneurysm, especially when the PcoA preservation is mandatory.

• Journal of Korean Neurosurgical Society
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• v.67 no.4
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• pp.411-417
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• 2024

Objective : To confirm the usefulness of the extradural anterior clinoidectomy during the clipping of a low riding posterior communicating artery (PCoA) aneurysm through cadaver dissection. Methods : Anatomic measurements of 12 adult cadaveric heads (24 sides total) were performed to compare the microsurgical exposure of the PCoA and internal carotid artery (ICA) before and after clinoidectomy. A standard pterional craniotomy and transsylvian approach were performed in all cadavers. The distance from the ICA bifurcation to the origin of PCoA (D1), pre-anterior clinoidectomy distance from the ICA bifurcation to tentorium (D2), post-anterior clinoidectomy distance from the ICA bifurcation to tentorium (D3), pre-anterior clinoidectomy distance from the tentorium to the origin of PCoA (D4) and post-anterior clinoidectomy distance from the tentorium to the origin of PCoA (D5) and the distance of the ICA obtained after anterior clinoidectomy (D6) were measured. We measured the precise thickness of the blade for the Yasargil clip with a digital precision ruler to confirm the usefulness of the extradural anterior clinoidectomy. Results : Twenty-four sites were dissected from 12 cadavers. The age of the cadavers was 79.83±6.25 years. The number of males was the same as the females. The space from the proximal origin of the PCoA to the preclinoid-tentorium (D4) was 1.45±1.08 mm (max, 4.01; min, 0.56). After the clinoidectomy, the space from the proximal origin of the PCoA to the postclinoid-tentorium (D5) was 3.612±1.15 mm (max, 6.14; min, 1.83). The length (D6) of the exposed proximal ICA after the extradural clinoididectomy was 2.17±1.04 mm on the lateral side and 2.16±0.89 mm on the medial side. The thickness of the Yasargil clip blade used during the clipping surgery was 1.35 mm measured with a digital precision ruler. Conclusion : The proximal length obtained by performing an external anterior clinoidectomy is about 2 mm, sufficient for proximal control during PCoA aneurysm surgery, considering the thickness of the aneurysm clips. In a subarachnoid hemorrhage, performing an extradural anterior clinoidectomy could prevent a devastating situation during PCoA aneurysm clipping.

• Journal of Korean Neurosurgical Society
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• v.65 no.4
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• pp.531-538
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• 2022

Objective : Anterior communicating artery (Acom) aneurysm is one of the most common intracranial aneurysms, constituting approximately 30-35% of all aneurysm formation in the brain. Anatomically, the H-complex (the anatomic morphology of both A1 to A2 segments) is thought to affects the nature of the Acom aneurysm due to its close relationship with the hemodynamics of the vessel. Therefore, we investigated the relative risk factors of aneurysmal rupture, especially focusing on H-complex morphology of the Acom. Methods : From January 2016 to December 2020, a total of 209 patients who underwent surgery, including clipping and coiling for Acom aneurysm in our institution were reviewed. There were 102 cases of ruptured aneurysm and 107 cases of unruptured aneurysm. The baseline morphology of aneurysms was investigated and the relationship between the H-complex and the clinical characteristics of patients with Acom aneurysms was assessed. Results : Of the 209 patients, 109 patients (52.1%) had symmetrical A1, 79 patients (37.8%) had unilateral hypoplastic A1, and 21 patients (10.0%) had aplastic A1. The hypoplastic A1 group and the aplastic A1 group were grouped together as unilateral dominancy of A1, and were compared with the symmetrical A1 group. There was no significant difference in demographic characteristics and radiological findings of Acom aneurysms between two groups. However, when dichotomizing the patients into ruptured cases and unruptured cases, unilateral dominance of the A1 segment was associated with aneurysmal rupture with statistical significance (p=0.011). Conclusion : These results suggest that the unilateral dominance of the A1 segment does not have a significant effect on the morphology of Acom aneurysms, but contributes to aneurysmal rupture. Thus, we can better understand the effects of hemodynamics on Acom aneurysm.

• Journal of Korean Neurosurgical Society
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• v.37 no.5
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• pp.329-335
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• 2005

Objective: Acute spontaneous subdural hematoma(SDH) secondary to a ruptured intracranial aneurysm is a rare event. The authors present nine cases with aneurysmal SDH. Methods: We analyzed nine cases of aneurysmal SDH from 337 patients who underwent treatment for a ruptured aneurysm between January 1998 and May 2004. Clinical and radiological characteristics and postoperative course were evaluated by reviewing medical records, surgical charts and intraoperative videos. Results: The nine patients comprised four males and five females with a mean age of 53years (range 15-67years). The World Federation of Neurosurgical Societies grades on admission were I in one patient, II in two patients, III in five patients and V in one patient. With respect to location, there were four internal carotid-posterior communicating artery(ICA-Pcom) aneurysms, one distal anterior cerebral artery(DACA) aneurysm, one anterior communicating artery and three middle cerebral artery aneurysms. CT scans obtained from the four patients with ICA-Pcom aneurysms revealed SDH over the convexity and along the tentorium, and two of these patients presented with pure SDH without subarachnoid hemorrhage(SAH). In three patients with ICA-Pcom aneurysm, the ruptured aneurysm domes adhered to the petroclinoid fold. In the patient with the DACA aneurysm, the domes adhered tightiy to the pia mater and the falx. Conclusion: Ruptured intracranial aneurysm may cause SDH with or without SAH. In the absence of trauma, the possibility of aneurysmal SDH should be considered.

• Journal of Korean Neurosurgical Society
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• v.42 no.5
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• pp.388-391
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• 2007

Objective : The focus of aneurysm surgery is eliminating unnecessary operative manipulations and preparing the surgeon for any crises that might arise. With this concept in mind, we have tried resection of the gyrus rectus without routine sylvian fissure dissection in selected patients with anterior communicating artery (ACom) aneurysms, and compared these results with those from the conventional transsylvian approach. Methods : This retrospective study included 231 surgically treated patients with ACom aneurysms from March, 1997 to May, 2005. The patients were divided into two groups : Group A (96 with sylvian fissure dissection, March, 1997-December, 2000) and Group B (135 without sylvian fissure dissection, January, 2001-May, 2005). Overall surgical outcomes were compared, and operative times have been prospectively recorded since January, 04 to evaluate how this maneuver affected the length of surgical procedures. Results : All aneurysms were satisfactorily clipped, and there was no evidence of increased number of procedure-related retraction injuries in group B. Overall outcome was good in 186 (80.5%); 76 (79.2%) in group A, and 110 (815%) in group B ($x^2$ test, p=0.79). In good clinical grade of group A, good outcome was observed in 60 patients (89.6%) and in group B, 97 patients (94.2%) (Fisher's exact test, p=0.38) (Fig. 2). Conclusion : In this study, eliminating the step of sylvian fissure dissection by gentle lateral basal-frontal retraction to the side of the sylvian fissure did not increase morbidity and mortality. However, we do not intend to modify the standard approach to the ACom aneurysm that is familiar to and has been mastered by many others. Rather, we report our experience on the basis of our anatomic understanding of the technique and its results.

• Journal of Korean Neurosurgical Society
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• v.37 no.6
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• pp.405-409
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• 2005

Objective: The purpose of this study is to assess the factors related to the outcome of 84 patients who underwent surgery for anterior communicating Artery(ACoA) aneurysms. Methods: The authors review 84 patients who were undertaken from January 1998 to May 2004. In the management of ACoA aneurysms, the outcome was based on several factors: Clinical condition, Distribution of hemorrhage, Time between aneurysmal rupture and surgery, Direction and shape of the aneurysm. Results: The incidence rate of the ACoA aneurysm was 35%. Seventy four patients were classified as those having a good recovery, but 5 patients suffered from some morbidity and 5 patients died. The rate of good outcome for the patients with Hunt and Hess grade was as follows 100% in grade I, 95% in grade II, 80% in grade III, IV and V. The rate of good outcome for the patients with Fisher grade was as follows 98% in grade I, II and 81% in grade III, IV. Nineteen of 22 patients who underwent early surgery were rated as good, while twenty six of 30 patients for whom surgery was delayed showed a favorable result. The unfavorable outcomes were also attributed by vasospasm or other medical problems. Conclusion: For further improvement of the overall surgical outcome: First, early surgical intervention is recommended for good grade patients. Second, active management of poor grade patients should be scrutinized with early surgery. Third, it is also important to step up the effort to minimize the risk of medical complications to enhance surgical results on top of the mainstay of prevention efforts for vasospasm and rebleeding.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup2
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• pp.337-339
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• 2001

The development of completely new intracranial aneurysms after previous successfully treated aneurysm is uncommon. A 50-year-old female presented with a case of multiple de novo aneurysm which were an aneurysm of right ophthalmic segment of internal carotid artery and an aneurysm of right A1 artery, 6 years after the clipping of an aneurysm of right posterior communicating artery. She had no history of hypertension, cigarette smoking and use of oral contraceptives, and had no evidence of genetic disorder. The laboratory findings were normal. All de novo aneurysms were clipped by basal anterior interhemispheric approach in one stage due to the direction of the aneurysm of the ophthalmic segment of the internal carotid artery.

• Journal of Korean Neurosurgical Society
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• v.48 no.4
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• pp.330-334
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• 2010

Objective : Residual aneurysm from incomplete clipping or slowly recurrent aneurysm is associated with high risk of subarachnoid hemorrhage. We describe complete treatment of the lesions by surgical clipping or endovascular treatment. Methods : We analyzed 11 patients of residual or recurrent aneurysms who had undergone surgical clipping from 1998 to 2009. Among them, 5 cases were initially clipped at our hospital. The others were referred from other hospitals after clipping. The radiologic and medical records were retrospectively analyzed. Results : All patients presented with subarachnoid hemorrhage at first time, and the most frequent location of the ruptured residual or recurrent aneurysm was in the anterior communicating artery to posterior-superior direction. Distal anterior cerebral artery, posterior communicating artery, and middle cerebral artery was followed. Repositioning of clipping in eleven cases, and one endovascular treatment were performed. No residual aneurysm was found in postoperative angiography, and no complication was noted in related to the operations. Conclusion : These results indicate the importance of postoperative or follow up angiography and that reoperation of residual or slowly recurrent aneurysm should be tried if such lesions being found. Precise evaluation and appropriate planning including endovascular treatment should be performed for complete obliteration of the residual or recurrent aneurysm.

• Journal of Korean Neurosurgical Society
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• v.50 no.2
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• pp.81-88
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• 2011

Objective : The purpose of this study was to analyze the clinical and anatomic features involved in determining treatment modalities for anterior communicating artery (AcoA) aneurysms. Methods : The authors retrospectively evaluated 112 AcoA aneurysms with pretreatment clinical features including age, Hunt and Hess grade, medical or neurological comorbidity, and anatomical features including aneurysm size, neck size, dome-to-neck ratio, vessel incorporation, multiple lobulation, and morphologic scoring system. Post-treatment clinical results were classified according to the Glasgow Outcome Scale, and anatomic results in coiled patients were classified according to the modified Raymond scale. Using multivariate logistic regression, the probabilities for decision making between surgical clipping and coil embolization were calculated. Results : Sixty-seven patients (60%) were treated with surgical clipping and 45 patients (40%) with endovascular coil embolization. The clinical factor significantly associated with treatment decision was age (${\geq}$65 vs. <65 years) and anatomical factors including aneurysm size (small or large vs. medium), dome-to-neck ratio (<2 vs. ${\geq}$2), presence of vessel incorporation, multiple lobulation, and morphologic score (${\geq}$2 vs. <2). In multivariate analysis, older patients (age, 65 years) had significantly higher odds of being treated with coil embolization relative to clipping (adjusted OR=3.78; 95% CI, 1.39-10.3; p=0.0093) and higher morphological score patients (${\geq}$2) had a higher tendency toward surgical clipping than endovascular coil embolization (OR=0.23; 95% CI, 0.16-0.93; p=0.0039). Conclusion : The optimal decision for treating AcoA aneurysms cannot be determined by any single clinical or anatomic characteristics. All clinical and morphological features need to be considered, and a collaborative neurovascular team approach to AcoA aneurysms is essential.