• Journal of Korean Neurosurgical Society
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• v.67 no.1
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• pp.22-30
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• 2024

Objective : This study aimed to determine the frequency of paraclinoid aneurysms among ruptured cerebral aneurysms and compare paraclinoid aneurysms with other aneurysms to clarify the characteristics of ruptured paraclinoid aneurysms. Methods : This study included 970 ruptured cerebral aneurysms treated at our hospital between 2003 and 2020. Results : There were 15 cases (1.3%) of paraclinoid aneurysms with maximum diameters of 5-22 mm (mean±standard deviation [SD], 11.6±5.4 mm). Treatment consisted of clipping in four patients and endovascular treatment in 11. Factors significantly different in multivariate analysis for paraclinoid aneurysms compared with those for other aneurysms were a history of hypertension (odds ratio [OR], 1.2-9.8; p=0.021) and aneurysm ≥10 mm (OR, 7.5-390.3; p<0.001). The sites of paraclinoid aneurysm were ophthalmic artery type in nine patients, anterior wall type in five, medial wall type in one, and ventral wall type in zero. The medial wall type (22 mm) was significantly larger than the ophthalmic artery type (mean±SD, 7.2±2.0 mm) (p=0.003), and the anterior wall type (mean±SD, 12.2±4.8 mm) was significantly larger than the ophthalmic artery type (p=0.024). Conclusion : This study showed a low frequency of paraclinoid aneurysms among ruptured cerebral aneurysms. Most were upward-facing with relatively large aneurysms, and no aneurysms were smaller than 5 mm. With recent advances in endovascular treatment devices, paraclinoid aneurysms are easily treatable. However, the treatment indication of each paraclinoid aneurysm should be carefully considered.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.20 no.4
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• pp.241-247
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• 2018

Treatment of paraclinoid aneurysms weather by surgery, or endovascular embolization has a risk of visual loss due to optic neuropathy, or diplopia due to cranial nerve palsies. Visual complications occur immediately after the clipping, whereas they can occur variable time after endovascular coiling. Recently, endovascular coiling for paraclinoid aneurysm is regarded as a safe and feasible treatment. But it still has risks of acute thromboembolic complication, or cranial nerve palsies. A 45-year-old woman was referred from local hospital to our hospital due to ruptured large ICA dorsal wall aneurysm. A total of 12 coils (195 cm) were used for obliteration of aneurysm. Postoperative diffusion weighted image showed no abnormal signal intensity lesion and magnetic resonance angiography demonstrated no sign of vasospasm, or vessel narrowing. But, she complained visual problem 23 days after coil embolization. Ophthalmologist confirmed the left optic disc atrophy on fundoscopy. Although steroid was started, but monocular blindness did not recover completely. The endovascular embolization of paraclinoid aneurysm, especially projecting superiorly with large irregular shape, has the risk of progressive visual loss because of the proximity to optic nerve.

• Journal of Korean Neurosurgical Society
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• v.30 no.12
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• pp.1361-1368
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• 2001

Objective : "Paraclinoid" aneurysms include those aneurysms arising from the internal carotid artery between the site of emergence of the carotid artery from the roof of the cavernous sinus and the origin of the posterior communicating artery. The authors reviewed and analysed the results of surgical approaches to paraclinoid aneurysms treated with transcranial surgery and endovascular surgery. Methods : Between January 1998 and May 1999, 14 patients were treated surgically through ipsilateral and contralateral pterional approaches, and anterior interhemispheric approach, and endovascular surgery for paraclinoid aneurysms. All transcranial approaches were performed by same surgeon. The medical records, neuroimaging studies and videotapes which had been recorded operations were reviewed retrospectively. Results : Twelve patients presented with subarachnoid hemorrhage and ICH. Nine of fourteen patients had multiple aneurysms. Thirteen cases were small and one was a large aneurysm. Six patients were treated through ipsilateral approaches, six contralateral pterional approaches, one anterior interhemispheric approach and one primarily by GDC embolization. All aneurysms treated through contralateral approaches were multiple aneurysms. Neck clipping was performed in 9(69.2%) of the thirteen aneurysms, wrapping in four cases, among them three cases were followed by GDC embolization. The surgical outcomes were : Glasgow Outcome Scale(GOS) I 71.4%, GOS II 21.4% and GOS V 7.1%. Conclusion : The surgical approaches to paraclinoid aneurysms should be chosen after careful anatomical evaluation of aneurysm and its neighboring structures. 3D-CT angiography and/or the raw data of MR angiography were useful. This study supports the usefulness of the contralateral approach to paraclinoid aneurysm associated with multiple aneurysms, unruptured and small aneurysms whose dome projecting medially, superiorly and dorsally. The determination of contralateral approach to small and medially projecting paraclinoid aneurysm may be stressful to operator, thus we believe anterior interhemispheric approach is better alternated. Also we recommend the endovascular surgery after reinforcement of aneurym neck and dome in the case with difficulty in clipping.

• Journal of Korean Neurosurgical Society
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• v.47 no.6
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• pp.437-441
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• 2010

Objective : The precise intra- vs. extradural localization of aneurysms involving the paraclinoid internal carotid artery is critical for the evaluation of patients being considered for aneurysm surgery. The purpose of this study was to investigate the clinical usefulness of T2-weighted threedimensional (3-D) fast spin-echo (FSE) magnetic resonance (MR) imaging in the evaluation of unruptured paraclinoid aneurysms. Methods : Twenty-eight patients with unruptured cerebral aneurysms in their paraclinoid regions were prospectively evaluated using a T2- weighted 3-D FSE MR imaging technique with oblique coronal sections. The MR images were assessed for the location of the cerebral aneurysm in relation to the dural ring and other surrounding anatomic compartments, and were also compared with the surgical or angiographic findings. Results : All 28 aneurysms were identified by T2-weighted 3D FSE MR imaging, which showed the precise anatomic relationships in regards to the subarachnoid space and the surrounding anatomic structures. Consequently, 13 aneurysms were determined to be intradural and the other 15 were deemed extradural as they were confined to the cavernous sinus. Of the 13 aneurysms with intradural locations, three superior hypophyseal artery aneurysms were found to be situated intradurally upon operation. Conclusion : High-resolution T2-weighted 3-D FSE MR imaging is capable of confirming whether a cerebral aneurysm at the paraclinoid region is intradural or extradural, because of the MR imaging's high spatial resolution. The images may help in identifying patients with intradural aneurysms who require treatment, and they also can provide valuable information in the treatment plan for paraclinoid aneurysms.

• Journal of Korean Neurosurgical Society
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• v.56 no.6
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• pp.496-499
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• 2014

Owing to the focal wall defect covered with thin fibrous tissues, an aneurysm arising from the dorsal wall of the internal carotid artery (ICA) is difficult to manage either surgically or endovascularly and is often associated with high morbidity and mortality. Unfortunately, the definitive treatment modality of such highly risky aneurysm has not yet been demonstrated. Upon encountering the complex intracranial pathophysiology of such a highly precarious aneurysm, a neurosurgeon would be faced with a challenge to decide on an optimal approach. This is a case of multiple paraclinoid aneurysms including the ICA dorsal wall aneurysm, presented with spontaneous subarachnoid hemorrhage. With respect to treatment, direct clipping with a Sundt graft clip was performed after multiple endovascular interventions had failed. This surgical approach can be a treatment modality for a blood blister-like aneurysm after failed endovascular intervention(s).

• Journal of Korean Neurosurgical Society
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• v.54 no.6
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• pp.477-483
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• 2013

Objective : Although surgical techniques for clipping paraclinoid aneurysms have evolved significantly in recent times, direct microsurgical clipping of large and giant paraclinoid aneurysms remains a formidable surgical challenge. We review here our surgical experiences in direct surgical clipping of large and giant paraclinoid aneurysms, especially in dealing with anterior clinoidectomy, distal dural ring resection, optic canal unroofing, clipping techniques, and surgical complications. Methods : Between September 2001 and February 2012, we directly obliterated ten large and giant paraclinoid aneurysms. In all cases, tailored orbito-zygomatic craniotomies with extradural and/or intradural clinoidectomy were performed. The efficacy of surgical clipping was evaluated with postoperative digital subtraction angiography and computed tomographic angiography. Results : Of the ten cases reported, five each were of ruptured and unruptured aneurysms. Five aneurysms occurred in the carotid cave, two in the superior hypophyseal artery, two in the intracavernous, and one in the posterior wall. The mean diameter of the aneurysms sac was 18.8 mm in the greatest dimension. All large and giant paraclinoid aneurysms were obliterated with direct neck clipping without bypass. With the exception of the one intracavenous aneurysm, all large and giant paraclinoid aneurysms were occluded completely. Conclusion : The key features of successful surgical clipping of large and giant paraclinoid aneurysms include enhancing exposure of proximal neck of aneurysms, establishing proximal control, and completely obliterating aneurysms with minimal manipulation of the optic nerve. Our results suggest that internal carotid artery reconstruction using multiple fenestrated clips without bypass may potentially achieve complete occlusion of large paraclinoid aneurysms.

• Journal of Korean Neurosurgical Society
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• v.38 no.2
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• pp.151-154
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• 2005

A 43-year-old woman was admitted with the chief complaint of progressive visual disturbance and her brain radiological studies disclosed well demarcated tumor at tuberculum sellae area and bilateral mirror image paraclinoid internal carotid artery saccular aneurysms. A larger left side aneurysm was pointing medialy and almost encased by the tumor. Although a brain tumor and intracranial aneurysm can be simultaneously treated by surgery, the high risk of intra-operative aneurysm rupture should be considered. Therefore, the author secondly performed tumor resection after the endovascular embolization of the aneurysm which was embedding the tumor using a Guglielmi detachable coil. After successful treatment of the patient with tuberculum sellae meningioma associated with bilateral mirror image paraclinoid aneurysms using endovascular and surgical techniques, the authors present the case with a review of the related literatures.

• Journal of Korean Neurosurgical Society
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• v.56 no.4
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• pp.344-347
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• 2014

Stent thrombosis is a major limitation of stent-assisted coiling, which is an effective method for treating wide-necked aneurysms. Although early in-stent thrombosis has been reported, very late stent thrombosis (VLST) (>1 year) has not been reported following implantation of a single self-expandable stent designed for coiling. Herein, the authors present a case of VLST that occurred 14 months after single stent implantation in a large paraclinoid aneurysm with an ultra-wide neck involving the parent artery circumferentially. This case indicates the need for establishing guidelines regarding the optimal duration of prophylactic antiplatelet therapy following stent-assisted coiling, which remains undefined in the neuroendovascular field.

• Journal of Korean Neurosurgical Society
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• v.48 no.3
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• pp.199-206
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• 2010

Objective : Paraclinoid segment internal carotid artery (ICA) aneurysms have historically been a technical challenge for neurovascular surgeons. The development of microsurgical approach, advances in surgical techniques, and endovascular procedures have improved the outcome for paraclinoid aneurysms. However, many authors have reported high complication rates from microsurgical treatments. Therefore, the present study reviews the microsurgical complications of the extradural anterior clinoidectomy for treating paraclinoid aneurysms and investigates the prevention and management of observed complications. Methods : Between January 2004 and April 2008, 22 patients with 24 paraclinoid aneurysms underwent microsurgical direct clipping by a cerebrovascular team at a regional neurosurgical center. Microsurgery was performed via an ipsilateral pterional approach with extradural anterior clinoidectomy. We retrospectively reviewed patients' medical charts, office records, radiographic studies, and operative records. Results : In our series, the clinical outcomes after an ipsilateral pterional approach with extradural anterior clinoidectomy for paraclinoid aneurysms were excellent or good (Glasgows Outcome Scale : GOS 5 or 4) in 87.5% of cases. The microsurgical complications related directly to the extradural anterior clinoidectomy included transient cranial nerve palsy (6), cerebrospinal fluid leak (1), worsened change in vision (1), unplanned ICA occlusion (1), and epidural hematoma (1). Only one of the complications resulted in permanent morbidity (4.2%), and none resulted in death. Conclusion : Although surgical complications are still reported to occur more frequently for the treatment of paraclinoid aneurysms, the permanent morbidity and mortality resulting from a extradural anterior clinoidectomy in our series were lower than previously reported. Precise anatomical knowledge combined with several microsurgical tactics can help to achieve good outcomes with minimal complications.

• Journal of Korean Neurosurgical Society
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• v.42 no.1
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• pp.35-41
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• 2007

Objective : Determining the location of paraclinoid aneurysms for microsurgery is important for selecting treatment options, especially when deciding on the release of the dural ring in direct clipping. We examined the reliability of using the optic strut as an anatomical landmark for evaluating the location of paraclinoid aneurysms. Methods : Cadaveric dissection was performed to establish the relationship of the optic strut to the dural ring. Results from these anatomic studies were compared with the three-demensional computed tomographic angiographic [3D-CTA] findings of nine patients with ten paraclinoid aneurysms between May 2004 and October 2005. These, 3D-CTA results were then compared with intraoperative findings. Results : The inferior boundary of the optic strut accurately localized the point at the proximal dural ring in cadaveric study. The optic strut and its relationship to the aneurysms was well observed on the multiplanar reformats of 3D-CTA. During microsurgery, nine of ten aneurysms were verified to arise from distal to the upper surface of the optic strut. Two aneurysms that had arisen between the inferior and superior boundary of the optic strut were observed to lie within the carotid cave. One aneurysm which had arisen at the inferior boundary of the optic strut and directed inferiorly was observed to lie within the cavernous sinus just after the release of the proximal ring. Conclusion : The optic strut, as identified with multiplanar reformats of 3D-CTA, provided a reliable anatomic landmark for the proximal rings and an important information about the location of aneurysms around the anterior clinoid process (ACP). Therefore, 3D-CTA and the optic strut could become an invaluable tool and a landmark in the assessment of the location of paraclinoid aneurysms for microsurgery.