Anterior paraclinoid aneurysms

2002 ◽  
Vol 96 (6) ◽  
pp. 1000-1005 ◽  
Author(s):  
Hiroyuki Kinouchi ◽  
Kazuo Mizoi ◽  
Yoshihide Nagamine ◽  
Noritaka Yanagida ◽  
Shigeki Mikawa ◽  
...  
Keyword(s):  
Special Group ◽  
Anterior Clinoid Process ◽  
Dorsal Wall ◽  
Content Type ◽  
Paraclinoid Aneurysm ◽  
Paraclinoid Aneurysms ◽  
Proximal Internal Carotid Artery ◽  
Female Predominance ◽  
Intradural Space ◽  
Fine Print

Object. The characteristics of a previously unclassified paraclinoid aneurysm arising from the anterolateral (dorsal) wall of the proximal internal carotid artery were retrospectively analyzed in seven patients (five women and two men) who were treated surgically for an aneurysm in this unusual location. Methods. One patient presented with subarachnoid hemorrhage (SAH) caused by rupture of this aneurysm. The lesions were found incidentally (five cases) or during investigation of SAH due to another aneurysm (one case). There was a female predominance in this series; all female patients harbored multiple aneurysms. All patients underwent surgery. Removal of the anterior clinoid process was necessary because the proximal neck of the aneurysm was closely adjacent to the dural ring. Conclusions. This special group of aneurysms is very rare, is located exclusively in the intradural space, and carries the risk of SAH. The results of surgical treatment for this aneurysm are quite satisfactory.

Removal of the anterior clinoid process for exposure of the proximal intracranial carotid artery

1988 ◽  
Vol 69 (4) ◽  
pp. 529-534 ◽  
Author(s):  
Stephen Lawrence Nutik
Keyword(s):  
Carotid Artery ◽  
Internal Carotid ◽  
Anterior Clinoid Process ◽  
Content Type ◽  
Cerebrospinal Fluid Rhinorrhea ◽  
Paraclinoid Aneurysm ◽  
Proximal Internal Carotid Artery ◽  
Temporary Occlusion ◽  
Autopsy Specimens ◽  
Angiographic Findings

✓ The anatomy of the carotid artery at the level of the anterior clinoid process was studied in autopsy specimens and at surgery. Marking clips placed at surgery were used to correlate anatomical and angiographic findings. Removal of the anterior clinoid process permits visualization of approximately 6 mm more of the proximal internal carotid artery without entering the cavernous sinus. The exposure reaches just to the hairpin bend of the carotid siphon, but the bend is not seen. The curve in the carotid artery which is observed after anterior clinoid removal is distal to the hairpin turn and corresponds to a bend seen on the anteroposterior projection of the angiogram. Temporary occlusion of the carotid artery proximal to a paraclinoid aneurysm is possible after clinoid removal. Complications of the removal include trauma to the third nerve and cerebrospinal fluid rhinorrhea.

Aneurysms of the ophthalmic segment

1990 ◽  
Vol 72 (5) ◽  
pp. 677-691 ◽  
Author(s):  
Arthur L. Day
Keyword(s):  
Carotid Artery ◽  
Ophthalmic Artery ◽  
Anterior Clinoid Process ◽  
Content Type ◽  
Visual Deficits ◽  
Clinical Presentations ◽  
Female Predominance ◽  
Operative Findings ◽  
Ophthalmic Segment Aneurysms ◽  
Fine Print

✓ The clinical, radiographic, and anatomical features in 80 patients with ophthalmic segment aneurysms were reviewed, and were categorized according to a presumed origin related to the ophthalmic (41 cases) or superior hypophyseal (39 cases) arteries. There was a marked female predominance (7:1) and high incidence of multiple aneurysms (45%) within this population. Clinical presentations included subarachnoid hemorrhage in 23 cases (29%) and visual deficits in 24 (30%); five patients exhibited both hemorrhage and visual loss. Twenty-eight aneurysms were incidentally identified. Ophthalmic artery aneurysms arose from the internal carotid artery (ICA) just distal to the ophthalmic artery, pointed superiorly or superomedially, and (when large) deflected the carotid artery posteriorly and inferiorly, closing the siphon. Abnormalities relating to vision were not identified until the aneurysm realized giant proportions. The optic nerve was typically displaced superomedially, which restricted contralateral extension until late in the clinical course; unilateral nasal field loss was seen in 12 patients. Nine patients had bilateral ophthalmic artery aneurysms which were often clipped via a unilateral craniotomy. Superior hypophyseal artery aneurysms arose just above the dural ring from the medial bend of the ICA, at the site of perforator origin to the superior aspect of the hypophysis, and had no direct association with the ophthalmic artery. The carotid artery was usually located lateral or superolateral relative to the aneurysm. These lesions could extend medially beneath the chiasm (suprasellar variant), producing a clinical and computerized tomography picture similar to a pituitary adenoma, or they could extend ventrally to burrow beneath the anterior clinoid process (paraclinoid variant). Preoperative categorization of these lesions according to their likely branch of origin provides excellent correlation with visual deficits and operative findings, and has allowed the author to clip 52 of 54 lesions, with very low operative or visual morbidity.

Radiometric analysis of paraclinoid carotid artery aneurysms

2002 ◽  
Vol 96 (4) ◽  
pp. 649-653 ◽  
Author(s):  
Yuichiro Tanaka ◽  
Kazuhiro Hongo ◽  
Tsuyoshi Tada ◽  
Hisashi Nagashima ◽  
Tetsuyoshi Horiuchi ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Horizontal Line ◽  
Anterior Clinoid Process ◽  
Content Type ◽  
Aneurysm Neck ◽  
Radiometric Analysis ◽  
Paraclinoid Aneurysms ◽  
The Mean ◽  
Fine Print

Object. Classification of paraclinoid carotid artery (CA) aneurysms based on their associated branching arteries has been confusing because superior hypophyseal arteries (SHAs) are too fine to appear opacified on cerebral angiograms. The authors performed a retrospective radiometric analysis of surgically treated paraclinoid aneurysms to elucidate their angiographic and anatomical characteristics. Methods. A retrospective analysis was made of 85 intradural paraclinoid aneurysms in which the presence or absence of branching arteries had been determined at the time of surgical clipping. The lesions were classified as supraclinoid, clinoid, and infraclinoid aneurysms based on their relation to the anterior clinoid process on lateral angiograms of the CA. The direction of the aneurysms were measured according to angles formed between the medial portion of the horizontal line crossing the aneurysm sac and the center of the aneurysm neck on anteroposterior angiograms. Branching arteries were associated with 68 aneurysms, of which 28 were ophthalmic artery (OphA) lesions (32.9%) and 40 were SHA ones (47.1%); associated branching arteries were absent in 17 aneurysms (20%). Twenty-five aneurysms (29.4%) were located at the supraclinoidal level, 46 (54.1%) at the clinoidal, and 14 (16.5%) at the infraclinoidal. The majority of aneurysms identified at the supraclinoidal level were OphA lesions (44%) or those unassociated with branching arteries (48%), with mean directions of 57° or 67°, respectively. At the clinoidal level, the mean directions of aneurysms were 76° in six lesions unassociated with branching arteries (13%), 43° in 16 OphA lesions (35%), and −11° in 24 SHA ones (52%). All aneurysms at the infraclinoidal level arose at the origin of the SHAs, with a mean direction of −29°, and most of these were embedded in the carotid cave. Conclusions. Aneurysms arising from the SHA can be distinguished from those not located at an arterial division by cerebral angiography, because SHA lesions are usually located at the medial or inferomedial wall of the internal carotid artery at the clinoidal or infraclinoidal level. Their distribution correlates well with the reported distribution of SHA origins. The carotid cave aneurysm is a kind of SHA lesion that originates at the most proximal intradural CA.

Intracranial neurenteric cysts

1991 ◽  
Vol 75 (1) ◽  
pp. 115-120 ◽  
Author(s):  
George P. Malcolm ◽  
Lindsay Symon ◽  
Brian Kendall ◽  
Manuel Pires
Keyword(s):  
Content Type ◽  
Congenital Lesions ◽  
Intradural Space ◽  
Fine Print

✓ Two cases of intracranial neurenteric cysts are reported and the literature is reviewed. Neurenteric cysts are rare congenital lesions that tend to occur in the spinal intradural space. An intracranial location is exceptional.

scholarly journals Surgically Relevant Bony Anatomical Variations in Paraclinoid Aneurysms-Three-Dimensional Multi-Detector Row Computed Tomography-Based Study

2017 ◽  
Vol 08 (03) ◽  
pp. 330-334 ◽  
Author(s):  
K. Suprasanna ◽  
Ashvini Kumar
Keyword(s):  
Computed Tomography ◽  
Cerebral Angiography ◽  
Three Dimensional ◽  
Anatomical Variations ◽  
Type I ◽  
Anterior Clinoid Process ◽  
Multiplanar Reconstructions ◽  
Paraclinoid Aneurysm ◽  
Paraclinoid Aneurysms ◽  
Caroticoclinoid Foramen

ABSTRACT Objective: To evaluate the proportion of surgically relevant anatomical variations such as caroticoclinoid foramen, interclinoid osseous bridge, and anterior clinoid pneumatization in patients with paraclinoid aneurysms based on computed tomography (CT) cerebral angiography studies. Materials and Methods: Fifty-four CT cerebral angiography studies showing paraclinoid aneurysms involving the cavernous, clinoid, and supraclinoid internal carotid artery (ICA) were retrospectively evaluated. Source images were processed for three-dimensional reconstructions to evaluate the presence and type of caroticoclinoid foramen, interclinoid osseous bridge, and multiplanar reconstructions with bone algorithm to study the type of pneumatization. Results: The study included 30 female and 24 male patients with mean age of 45.61 (10.47) years. Among the 108 sides studied in 54 patients, caroticoclinoid foramen was seen in 24 cases (22.22%), interclinoid osseous bridge was seen unilaterally in 1 case (0.9%), and pneumatization of anterior clinoid process occurred in 12 cases (11.11%). Incomplete caroticoclinoid foramen (11 cases) and Type I pneumatization (7 cases) were seen to be predominant subtypes. There was no statistically significant gender difference in the occurrence of caroticoclinoid foramen and anterior clinoid pneumatization. Seventy-four aneurysms were detected in 54 patients. Based on their location, 46 aneurysms involved supraclinoid ICA, 18 aneurysms in the clinoid segment, and 10 aneurysms in the cavernous segment. Caroticoclinoid foramen was most prevalent in clinoid aneurysms with 12 cases occurring in the clinoid segment. Conclusion: Notable proportions of caroticoclinoid foramen and pneumatization occur in cases of paraclinoid aneurysm. Radiological reports should emphasize on these surgically relevant bony anatomical variations.

Carotid paraclinoid aneurysms with intradural origin and intracavernous location

1978 ◽  
Vol 48 (4) ◽  
pp. 526-533 ◽  
Author(s):  
Stephen Nutik
Keyword(s):  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Internal Carotid ◽  
Precise Definition ◽  
Separate Entity ◽  
Content Type ◽  
Paraclinoid Aneurysms ◽  
Planning Treatment ◽  
Definition Of ◽  
Fine Print

✓ Five cases of a congenital berry aneurysm of the internal carotid artery with origin partially intradural and fundus mainly intracavernous are presented. Angiography does not allow a precise definition of the amount of aneurysm that is intradural, a fact of importance when planning treatment of these cases. However, the angiographic features are characteristic of the type and suggest that these aneurysms be grouped together as a separate entity.

Surgical anatomy of the juxta—dural ring area

1998 ◽  
Vol 89 (2) ◽  
pp. 250-254 ◽  
Author(s):  
Susumu Oikawa ◽  
Kazuhiko Kyoshima ◽  
Shigeaki Kobayashi
Keyword(s):  
Surgical Anatomy ◽  
Lateral View ◽  
Horizontal Line ◽  
Anterior Clinoid Process ◽  
Lateral Projection ◽  
Content Type ◽  
Medial Side ◽  
Tuberculum Sellae ◽  
Planum Sphenoidale ◽  
Fine Print

Object. The authors report on the surgical anatomy of the juxta—dural ring area of the internal carotid artery to add to the information available about this important structure. Methods. Twenty sides of cadaver specimens were used in this study. The plane of the dural ring was found to incline in the posteromedial direction. Medial inclination was measured at 21.8° on average against the horizontal line in the anteroposterior view on radiographic studies. Posterior inclination was measured at 20.3° against the planum sphenoidale in the lateral projection, and the medial edge of the dural ring was located 0.4 mm above the tuberculum sellae in the same projection. The lateral edge of the dural ring was located 1.4 mm below the superior border of the anterior clinoid process. The carotid cave was situated at the medial or posteromedial aspect of the dural ring; however, two of the 20 specimens showed no cave formation. The carotid cave contained the subarachnoid space in 13 sides, the arachnoid membrane only in three sides, and the extraarachnoid space in two sides. The authors propose that the marker of the medial side of the dural ring, which is more proximal than the lateral, is the tuberculum sellae in the lateral view on radiographic studies. In the medial aspect of the dural ring the intradural space can be situated below the level of the tuberculum sellae because of the existence of the carotid cave. Conclusions. An aneurysm arising from the medial side of the juxta—dural ring area even below the tuberculum sellae is a potential cause of subarachnoid hemorrhage.

Dural arteriovenous shunts at the craniocervical junction

1998 ◽  
Vol 89 (5) ◽  
pp. 755-761 ◽  
Author(s):  
Hiroyuki Kinouchi ◽  
Kazuo Mizoi ◽  
Akira Takahashi ◽  
Yoshihide Nagamine ◽  
Keiji Koshu ◽  
...  
Keyword(s):  
Venous Drainage ◽  
Craniocervical Junction ◽  
Vertebral Angiography ◽  
Content Type ◽  
Arteriovenous Shunts ◽  
Dural Arteriovenous Shunts ◽  
Intradural Space ◽  
Tomography Scanning ◽  
Fine Print

Object. A retrospective analysis was conducted of 10 patients (three women and seven men) who were treated for spinal dural arteriovenous shunts (AVSs) located at the craniocervical junction. This analysis was performed to evaluate the characteristics of this unusual location in contrast with those of the more common thoracic and lumbar AVSs. Methods. Seven patients presented with subarachnoid hemorrhage (SAH) and one with slowly progressive quadriparesis and dyspnea due to myelopathy. The other two cases were detected incidentally and included a transverse—sigmoid dural AVS and a cerebellar arteriovenous malformation. Angiographic studies revealed that the spinal dural AVSs at the C-1 and/or C-2 levels were fed by the dural branches of the radicular arteries that coursed from the vertebral artery and drained into the medullary veins. Venous drainage was caudally directed in the patient with myelopathy. In contrast, the shunt flow drained mainly into the intracranial venous system in patients with SAH. Furthermore, in four of these patients a varix was found on the draining vein. In all patients, the draining vein was interrupted surgically at the point at which this vessel entered the intradural space, using intraoperative digital subtraction angiography to monitor flow. The postoperative course was uneventful in all patients and no recurrence was confirmed on follow-up angiographic studies obtained in seven patients at 6 months after discharge. Conclusions. If computerized tomography scanning shows SAH predominantly in the posterior fossa and no abnormalities are found on intracranial four-vessel angiographic study, proximal vertebral angiography should be performed to detect dural AVS at the craniocervical junction. The results of surgical intervention for this disease are quite satisfactory.

Extradural temporopolar approach to lesions of the upper basilar artery and infrachiasmatic region

1994 ◽  
Vol 81 (2) ◽  
pp. 230-235 ◽  
Author(s):  
J. Diaz Day ◽  
Steven L. Giannotta ◽  
Takanori Fukushima
Keyword(s):  
Basilar Artery ◽  
Cranial Nerve ◽  
Pathological Process ◽  
Total Resection ◽  
Anterior Clinoid Process ◽  
Content Type ◽  
Surgical Access ◽  
Complete Obliteration ◽  
Brain Retraction ◽  
Fine Print

✓ Surgical access to the parasellar, infrachiasmatic, and posterior clinoid regions has traditionally been accomplished through an intradural pterional or subtemporal approach. However, for large or complex lesions in these locations, such traditional trajectories may not afford sufficient exposure for complete obliteration of the pathological process. The authors describe an anterolateral transcavernous approach to this region that includes the following components: 1) extradural removal of the sphenoid wing and exposure of the superior orbital fissure and foramen rotundum; 2) removal of the anterior clinoid process via the anterolateral route; 3) decompression of the optic canal; 4) extradural retraction of the temporal tip; 5) transcavernous mobilization of the carotid artery and third cranial nerve; and 6) removal of the posterior clinoid process. This method results in enhanced exposure with minimal brain retraction and preservation of the temporal tip bridging veins. This approach has been used in 22 patients: 10 with basilar top aneurysms, eight with craniopharyngiomas, one with a tuberculum sellae meningioma, and two with trigeminal neuromas; the last patient had a carotidcavernous fistula and a concomitant pituitary adenoma. Complete clip ligation was performed for all 10 basilar artery aneurysms, and gross total resection was achieved with preservation of the pituitary stalk in all tumor cases. Microscopic total resection was not possible in two cases of craniopharyngioma due to hypothalamic invasion. Two patients suffered transient postoperative hemiparesis, and one patient has persisting weakness; however, no patient followed for more than 6 months suffered any persistent cranial nerve morbidity. It is concluded that this procedure can serve as an alternative to either the transsylvian or subtemporal approaches when cranial base pathologies are large or complex.

Subclinoid aneurysms

2003 ◽  
Vol 98 (4) ◽  
pp. 731-736 ◽  
Author(s):  
Stephen L. Nutik
Keyword(s):  
Blood Flow ◽  
Carotid Artery ◽  
Lateral Surface ◽  
Ophthalmic Artery ◽  
Anterior Clinoid Process ◽  
Content Type ◽  
Proximal Neck ◽  
Anatomical Features ◽  
Fine Print

Object. This study was undertaken to analyze the features that define subclinoid aneurysms. Methods. Five cases of laterally directed carotid artery (CA) aneurysms adjacent to the anterior clinoid process (ACP) were identified in a series of approximately 1400 surgically treated aneurysms. These cases were selected because the aneurysms had the same features as the only previously described “subclinoid” aneurysm. The angiographic and anatomical features of the five cases were analyzed. Conclusions. Subclinoid aneurysms are a unique group of congenital berry aneurysms. They originate from the lateral surface of the CA adjacent to the ACP. They are partially or completely hidden from view at surgery by the ACP and are partially or completely proximal to the distal dural ring of the CA. The proximal neck of these lesions is located at the same level of the CA cut perpendicular to its axis of blood flow as the origin of the ophthalmic artery (OphA), but they do not originate at that or any other branch of the CA. They can only be definitively differentiated from OphA, anterior paraclinoid, and blister-like aneurysms at surgery.

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