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.

Split spinal cord malformations in children

1998 ◽  
Vol 88 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Yusuf Ersşahin ◽  
Saffet Mutluer ◽  
Sevgül Kocaman ◽  
Eren Demirtasş
Keyword(s):  
Spinal Cord ◽  
Neurological Deficits ◽  
Single Type ◽  
Type I ◽  
Type Ii ◽  
Content Type ◽  
Spinal Lesion ◽  
The Mean ◽  
Fine Print

Object. The authors reviewed and analyzed information on 74 patients with split spinal cord malformations (SSCMs) treated between January 1, 1980 and December 31, 1996 at their institution with the aim of defining and classifying the malformations according to the method of Pang, et al. Methods. Computerized tomography myelography was superior to other radiological tools in defining the type of SSCM. There were 46 girls (62%) and 28 boys (38%) ranging in age from less than 1 day to 12 years (mean 33.08 months). The mean age (43.2 months) of the patients who exhibited neurological deficits and orthopedic deformities was significantly older than those (8.2 months) without deficits (p = 0.003). Fifty-two patients had a single Type I and 18 patients a single Type II SSCM; four patients had composite SSCMs. Sixty-two patients had at least one associated spinal lesion that could lead to spinal cord tethering. After surgery, the majority of the patients remained stable and clinical improvement was observed in 18 patients. Conclusions. The classification of SSCMs proposed by Pang, et al., will eliminate the current chaos in terminology. In all SSCMs, either a rigid or a fibrous septum was found to transfix the spinal cord. There was at least one unrelated lesion that caused tethering of the spinal cord in 85% of the patients. The risk of neurological deficits resulting from SSCMs increases with the age of the patient; therefore, all patients should be surgically treated when diagnosed, especially before the development of orthopedic and neurological manifestations.

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.

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.

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.

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.

Ventral paraclinoid carotid aneurysms

1988 ◽  
Vol 69 (3) ◽  
pp. 340-344 ◽  
Author(s):  
Stephen L. Nutik
Keyword(s):  
Carotid Artery ◽  
Ophthalmic Artery ◽  
Ventral Surface ◽  
Posterior Communicating Artery ◽  
Anterior Clinoid Process ◽  
Content Type ◽  
Multiple Aneurysms ◽  
High Incidence ◽  
Carotid Aneurysms ◽  
Fine Print

✓ A series of 15 patients with 17 ventral paraclinoid carotid artery aneurysms is presented. With this type of aneurysm the neck is at or just distal to the level of the ophthalmic artery and proximal to the posterior communicating artery on the ventral surface of the carotid artery. There is a high incidence of female patients and multiple aneurysms. At surgery, the aneurysms are hidden by the anterior clinoid process and often have an intracavernous component. The neck of the aneurysm is usually intradural and can be clipped.

Giant carotid-ophthalmic artery aneurysms: direct clipping utilizing the “trapping-evacuation” technique

1991 ◽  
Vol 74 (4) ◽  
pp. 567-572 ◽  
Author(s):  
Norihiko Tamaki ◽  
Shigekuni Kim ◽  
Kazumasa Ehara ◽  
Masahiro Asada ◽  
Katsuzo Fujita ◽  
...  
Keyword(s):  
Anterior Part ◽  
Giant Aneurysm ◽  
Postoperative Outcome ◽  
Balloon Occlusion ◽  
External Carotid ◽  
Anterior Clinoid Process ◽  
Content Type ◽  
Aneurysm Neck ◽  
Balloon Occlusion Test ◽  
Fine Print

✓ The authors have devised a “trapping-evacuation” technique to facilitate direct clipping of giant aneurysms in the paraophthalmic region of the internal carotid artery (ICA). The giant aneurysm is collapsed by first trapping the aneurysm by temporary occlusion of the cervical common carotid and external carotid arteries, along with temporary clipping of the intracranial ICA distal to the aneurysm. Thereafter, intra-aneurysmal blood is simultaneously aspirated through a catheter placed in the cervical ICA. Exposure of the proximal end of the aneurysm neck is mandatory for successful clipping. This is accomplished by extensive unroofing of the optic canal, removal of the anterior clinoid process, opening of the anterior part of the cavernous sinus, and exposure of the most proximal intradural (C2) and genu (C3) portions of the ICA. Four cases of giant aneuryms of the paraophthalmic ICA were successfully treated by this technique and the postoperative outcome was good in all cases. Preoperative magnetic resonance imaging for evaluation of the anatomical details, balloon occlusion test of the ICA, and intraoperative measurement of cortical blood flow were important to the success of the operation. Intraoperative digital subtraction angiography via the catheter placed in the cervical ICA was useful in confirming successful clipping.

Balloon-assisted microvascular clipping of paraclinoid aneurysms

2004 ◽  
Vol 100 (4) ◽  
pp. 713-716 ◽  
Author(s):  
William Thorell ◽  
Peter Rasmussen ◽  
John Perl ◽  
Thomas Masaryk ◽  
Marc Mayberg
Keyword(s):  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Internal Carotid ◽  
Direct Result ◽  
Parent Vessel ◽  
Content Type ◽  
Complex Aneurysms ◽  
Microsurgical Clipping ◽  
Paraclinoid Aneurysms ◽  
Fine Print

✓ Paraclinoid aneurysms represent a significant surgical challenge. Multiple techniques have been developed to maximize the effectiveness and safety of excluding these aneurysms from the cerebral circulation. Endovascular balloons have been used for proximal control of parent arteries during the treatment of aneurysms. In this report the authors describe the technique of navigating an endovascular balloon across the neck of paraclinoid aneurysms in four patients to gain proximal control, improve the accuracy of clip placement, and reduce the risk of distal embolization of intraluminal thrombus. Six consecutive patients with giant or complex aneurysms of the ophthalmic or paraclinoid internal carotid artery that were not amenable to endovascular obliteration were retrospectively analyzed. In all six patients, the aneurysm was exposed and dissected for microsurgical clipping, and attempts were made to navigate a nondetachable, compliant silicone balloon across the neck of the aneurysm. If successfully placed, the balloon was inflated during clip placement. In four patients, the balloon was successfully navigated across the neck of the aneurysm and was inflated during clip application. Internal carotid artery tortuosity precluded navigation of the balloon into the intracranial circulation in two patients. All aneurysms were completely excluded from the parent vessel according to postoperative angiography studies. No complication occurred as a direct result of the endovascular portion of the procedure. Endovascular balloon stenting of complex paraclinoid aneurysms during microvascular clipping may provide an adjunctive therapy that facilitates safe and accurate clip placement.

Simultaneous microscopic and endoscopic monitoring during surgery for internal carotid artery aneurysms

2004 ◽  
Vol 101 (6) ◽  
pp. 989-995 ◽  
Author(s):  
Hiroyuki Kinouchi ◽  
Toshiharu Yanagisawa ◽  
Akira Suzuki ◽  
Tohru Ohta ◽  
Yoshitaka Hirano ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Internal Carotid ◽  
Bone Structure ◽  
Surgical Complication ◽  
Artery Aneurysm ◽  
Content Type ◽  
Paraclinoid Aneurysms ◽  
Perforating Arteries ◽  
Fine Print

Object. The authors of this study evaluated the efficacy of simultaneous microscopic and endoscopic monitoring during surgery for internal carotid artery (ICA) aneurysms. Methods. The endoscopic technique was applied during microsurgery in 11 patients with 13 aneurysms. Nine of these lesions were located on the posterior communicating artery (PCoA), three in the paraclinoid region, and one on the anterior choroidal artery (AChA). Eight patients had unruptured aneurysms and three had ruptured aneurysms. The endoscope was introduced after first exposing the aneurysm through the microscope and was gripped firmly by an air-locked holding arm fitted with a steering system throughout the entire surgery, including dissection of the perforating arteries and application of the aneurysm clips. Regarding paraclinoid aneurysms, clips were applied through direct visualization of the ophthalmic artery and the proximal neck. In a case involving a superior hypophyseal artery aneurysm in the paraclinoid segment, a ring clip was applied without removing the bone structure around the optic canal. In all aneurysms of the PCoA and the AChA, perforating arteries behind the lesion were identified and dissected using endoscopic control. The aneurysm clip was applied in the best position in a single attempt in 10 of 11 patients. There was no surgical complication related to the endoscopic procedures. Conclusions. Simultaneous monitoring with the microscope and endoscope is extremely useful in applying clips to ICA aneurysms. This combined method allows for direct dissection of the aneurysm, perforating vessels, and the main trunk in an area not visible through the microscope's eyepiece and promises better surgical results.

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