Computer-generated microsurgical anatomy of the basilar artery bifurcation

1999 ◽  
Vol 91 (1) ◽  
pp. 145-152 ◽  
Author(s):  
Toru Koyama ◽  
Hiroshi Okudera ◽  
Hirohiko Gibo ◽  
Shigeaki Kobayashi
Keyword(s):  
Computer Graphics ◽  
Basilar Artery ◽  
Surgical Simulation ◽  
Critical Path ◽  
Cranial Nerves ◽  
Microsurgical Anatomy ◽  
Content Type ◽  
Transsylvian Approach ◽  
Bifurcation Aneurysm ◽  
Fine Print

✓ The authors' goal was to develop a computer graphics model to represent the microsurgical anatomy of the basilar artery (BA) bifurcation and surrounding structures to simulate surgery of a BA bifurcation aneurysm performed via the transsylvian approach.The source of the input data was a variety of publications that showed detailed anatomy of the area. A computer graphics model of the area near the BA bifurcation including relevant structures, such as perforating branches or cranial nerves, was depicted in detail. A BA bifurcation aneurysm was added to the computer graphics model and it was rotated to simulate the transsylvian approach. After the internal carotid artery was displaced using a virtual retractor, the aneurysm was exposed, thus providing an understanding of the three-dimensional surgical orientation of the area.Designing a standard anatomical model on the basis of data culled from a variety of publications and adding morphological changes by using a virtual retractor to displace structures that obstruct the view along a critical path at the base of the brain are useful strategies of computer manipulation for surgical simulation in open microneurosurgery. This methodological tool would be useful in teaching surgical microanatomy and in introducing a new navigational system for virtual reality. Both concept and technical details are discussed.

Pterional craniotomy via a transcavernous approach for the treatment of low-lying distal basilar artery aneurysms

1998 ◽  
Vol 89 (6) ◽  
pp. 921-926 ◽  
Author(s):  
Stephen L. Nutik
Keyword(s):  
Cavernous Sinus ◽  
Basilar Artery ◽  
Anterior Clinoid Process ◽  
Technical Problems ◽  
Content Type ◽  
Pterional Craniotomy ◽  
Transsylvian Approach ◽  
Posterior Clinoid Process ◽  
Additional Exposure ◽  
Fine Print

Object. The author describes a surgical procedure in which pterional craniotomy is performed via a transcavernous approach to treat low-lying distal basilar artery (BA) aneurysms. This intradural procedure is compared with the extradural procedure described by Dolenc, et al. Methods. The addition of a transcavernous exposure to the standard pterional intradural transsylvian approach allows a lower exposure of the distal BA behind the dorsum sellae. The technical steps involved in this procedure are as follows: 1) removal of the anterior clinoid process: 2) entry into the cavernous sinus medial to the third nerve; 3) packing of the venous channels of the cavernous sinus lying between the carotid artery and the pituitary gland to open this space; 4) removal of the posterior clinoid process and the portion of the dorsum sellae that is exposed from within the cavernous sinus; and 5) removal of the exposed dura mater to obtain additional exposure of the perimesencephalic cistern. Eight cases of aneurysms of the distal BA are presented to illustrate how this approach can help in their surgical treatment. Conclusions. Using the standard pterional approach, these distal BA aneurysms were found to be either too low relative to the posterior clinoid process for adequate exposure or there was insufficient room for temporary clipping of the BA proximal to the lesion. The addition of a transcavernous exposure eliminated these technical problems and aneurysm clipping could be accomplished in each case.

Computer-generated surgical simulation of morphological changes in microstructures: concepts of “virtual retractor”

1999 ◽  
Vol 90 (4) ◽  
pp. 780-785 ◽  
Author(s):  
Toru Koyama ◽  
Hiroshi Okudera ◽  
Shigeaki Kobayashi
Keyword(s):  
Optic Nerve ◽  
Computer Graphics ◽  
Surgical Simulation ◽  
Morphological Changes ◽  
Illustrative Case ◽  
Content Type ◽  
Operative Planning ◽  
Spatial Coordinates ◽  
Navigational System ◽  
Fine Print

✓ The authors' goal was to develop a computer graphics model to simulate the displacement and morphological changes that are caused by the retraction of fine intracranial structures.The authors developed an application program to interpolate the contour of models of an artery and a retractor. The center of the displacement was determined by spatial coordinates, and the shape of the displacement of the arterial model was calculated using a cosine-based formula with representation of a brain retractor. This computer graphics model was applied to the simulation of the displacement and morphological changes that occur when retraction is performed in the optic nerve. An illustrative case is presented, in which the optic nerve was displaced by a retractor to simulate the surgery performed in a carotid cave aneurysm of the internal carotid artery.The authors have named this methodological tool a “virtual retractor.” This new navigational system for open microneurosurgery would be useful in teaching surgical microanatomy and in presurgical operative planning.

Simulation of the surgical manipulation involved in clipping a basilar artery aneurysm: concepts of virtual clipping

2000 ◽  
Vol 93 (2) ◽  
pp. 355-360 ◽  
Author(s):  
Toru Koyama ◽  
Kazuhiro Hongo ◽  
Yuichiro Tanaka ◽  
Shigeaki Kobayashi
Keyword(s):  
Cerebral Aneurysm ◽  
Basilar Artery ◽  
Morphological Changes ◽  
Three Dimensional ◽  
Artery Aneurysm ◽  
Content Type ◽  
Aneurysm Clip ◽  
Transsylvian Approach ◽  
Surgical Manipulation ◽  
Fine Print

✓ Despite recent advances in three-dimensional imaging based on a voxel-rendering method, these techniques do not simulate the morphological changes that occur during surgery. The authors' goal was to develop a computer-graphics model to simulate the manipulation that occurs during surgery when clipping a cerebral aneurysm.The authors developed an application program to interpolate the contours of models of an artery and an aneurysm clip. The center of displacement was determined inside the arterial model. The directions of displacement were changed to simulate saccular and broad-neck aneurysms, and the intensity of displacement was calculated by using a cosine-based formula. The morphological changes in a saccular aneurysm that may occur during clipping were calculated in x, y, and z coordinates by using sine- and cosine-based formulas. Clip movement was integrated with the aneurysm model, thus simulating the manipulation used during clipping of a cerebral aneurysm. Surgery performed to clip a basilar artery (BA) aneurysm via the transsylvian approach was simulated, in which displacement of the internal carotid artery and clipping of the BA aneurysm were necessary. The movements of an aneurysm clip and clip applicator were designed to represent those occurring when a surgeon actually manipulates a BA aneurysm.The authors have named this methodological tool “virtual clipping.” Use of this tool would assist the preoperative choice of clipping style and selection of the best clip.

Microsurgical anatomy of the interpeduncular cistern and related arachnoid membranes

2005 ◽  
Vol 103 (2) ◽  
pp. 337-341 ◽  
Author(s):  
Jian Lü ◽  
Xianli Zhu
Keyword(s):  
Basilar Artery ◽  
Cerebral Arteries ◽  
Microsurgical Anatomy ◽  
Operating Microscope ◽  
Cranial Cavity ◽  
Content Type ◽  
Interpeduncular Cistern ◽  
Chinese Adult ◽  
Oculomotor Nerves ◽  
Fine Print

Object. The goal of this study was to investigate the microsurgical anatomy of the interpeduncular cistern and related arachnoid membranes. Methods. The interpeduncular cistern and related arachnoid membranes were studied in eight Han Chinese adult human cadaveric brains with the aid of an operating microscope. The interpeduncular cistern is one area in the cranial cavity in which the arachnoid membranes and trabeculae are extremely luxuriant and complicated. The Liliequist membrane, the medial pontomesencephalic membrane, and the lateral pontomesencephalic membranes form the walls of the interpeduncular cisterns. The basilar artery (BA) bifurcation membrane, posterior perforated membrane, and arachnoid trabeculae fill the cistern. These arachnoid membranes and trabeculae adhere to the hypothalamus, brainstem, and oculomotor nerves, and bind the bifurcation of the BA, posterior cerebral arteries, superior cerebellar arteries, posterior communicating arteries, and their perforating branches. Conclusions. Arachnoid membranes and trabeculae complicate the exposure and dissection of lesions within the interpeduncular cistern. All arachnoid membranes and trabeculae should be dissected and incised sharply during surgical procedures. The BA bifurcation membrane and the posterior perforated membrane must be incised after opening the Liliequist membrane for sufficient exposure of deep structures within the interpeduncular cistern.

Association between an aplastic basilar artery, unaccompanied by a primitive carotid—vertebrobasilar anastomosis, and multiple aneurysms on the dominant posterior communicating artery

2004 ◽  
Vol 100 (5) ◽  
pp. 946-949 ◽  
Author(s):  
Sanjay Behari ◽  
Himanshu Krishna ◽  
Marakani V. Kiran Kumar ◽  
Vijay Sawlani ◽  
Rajendra V. Phadke ◽  
...  
Keyword(s):  
Basilar Artery ◽  
Posterior Communicating Artery ◽  
Cerebral Vasculature ◽  
Hemodynamic Changes ◽  
Meningeal Irritation ◽  
Content Type ◽  
Third Nerve Palsy ◽  
Transsylvian Approach ◽  
The Right ◽  
Fine Print

✓ Basilar artery (BA) aplasia when unaccompanied by a primitive carotid—vertebrobasilar anastomosis is exceedingly rare. The association of BA aplasia with two aneurysms on the dominant posterior communicating artery (PCoA) has not been previously reported. This 40-year-old man presented in a state of drowsiness and responded to simple commands only after being coaxed. He had complete left cranial third nerve palsy, right hemiparesis, and persisting signs of meningeal irritation. A computerized tomography (CT) scan revealed subarachnoid and intraventricular hemorrhage. An angiogram revealed BA aplasia. The right PCoA followed a sinuous course with multiple loops and provided the dominant supply to the posterior circulation. This vessel harbored two aneurysms, one at the origin of the PCoA from the internal carotid artery and the other at the looping segment just proximal to the brainstem. The left PCoA was extremely thin. The pterional transsylvian approach was used to clip the two aneurysms on the PCoA. The hemodynamic changes produced by the BA aplasia may have produced alterations in the cerebral vasculature leading to aneurysm formation and consequent subarachnoid hemorrhage.

Evaluation of prostaglandin biosynthetic activity in canine basilar artery following subarachnoid injection of blood

1981 ◽  
Vol 55 (5) ◽  
pp. 771-778 ◽  
Author(s):  
Tomio Sasaki ◽  
Sei-itsu Murota ◽  
Susumu Wakai ◽  
Takao Asano ◽  
Keiji Sano
Keyword(s):  
Arachidonic Acid ◽  
Platelet Aggregation ◽  
Cerebral Artery ◽  
Basilar Artery ◽  
Biosynthetic Activity ◽  
Content Type ◽  
Blood Injection ◽  
Canine Basilar Artery ◽  
Subarachnoid Blood ◽  
Fine Print

✓ Transformation of arachidonic acid into prostaglandins was investigated in the basilar artery by incubating sections of artery with carbon-14-labeled arachidonic acid. Thin-layer radiochromatography revealed that, in normal canine basilar arteries, 14C-arachidonic acid was transformed mainly to 6-ketoprostaglandin (PG)F1α, a spontaneous metabolite of prostacyclin (PGI2). Among other prostaglandins, only a small amount of PGF2α was detected, whereas PGD2, PGE2, and thromboxane B2 were not. Arteries removed on Days 3 and 8 after subarachnoid blood injection showed a prostaglandin synthesis profile similar to that in the normal cerebral artery. In borate-buffered saline (0.1M borate buffer, pH 9.0/0.15M NaCl = 1:9, vol/vol), canine basilar artery produced a PGI2-like substance that inhibited adenosine diphosphate (ADP)-induced platelet aggregation. Its anti-aggregatory activity was completely abolished by acidification. Aspirin likewise inhibited production of the anti-aggregatory substance. From these results, it was concluded that the anti-aggregatory activity was due solely to the production of PGI2 by the arterial specimen. Based on the above results, PGI2 biosynthetic activity in the cerebral artery exposed to subarachnoid blood injection was bioassayed by measuring the inhibitory activity of the incubation product upon ADP-induced platelet aggregation following incubation of the arteries in borate-buffered saline for 5 to 30 minutes at 20°C, using synthetic PGI2-Na as a standard. The synthetic activity of PGI2 in the artery exposed to subarachnoid blood injection had diminished remarkably by Days 3 and 8. This diminution of PGI2 synthesis in the cerebral artery may be involved in the pathogenesis of cerebral vasospasm.

A fatal, chronically growing basilar artery: a new type of dissecting aneurysm

1996 ◽  
Vol 84 (6) ◽  
pp. 962-971 ◽  
Author(s):  
Tohru Mizutani
Keyword(s):  
Mr Imaging ◽  
Basilar Artery ◽  
Dissecting Aneurysm ◽  
Neurological Deficits ◽  
Vertebrobasilar Insufficiency ◽  
Content Type ◽  
Asymptomatic Patients ◽  
Basilar Arteries ◽  
Fine Print

✓ A long-term follow-up study (minimum duration 2 years) was made of 13 patients with tortuous dilated basilar arteries. Of these, five patients had symptoms related to the presence of such arteries. Symptoms present at a very early stage included vertebrobasilar insufficiency in two patients, brainstem infarction in two patients, and left hemifacial spasm in one patient. Initial magnetic resonance (MR) imaging in serial slices of basilar arteries obtained from the five symptomatic patients showed an intimal flap or a subadventitial hematoma, both of which are characteristic of a dissecting aneurysm. In contrast, the basilar arteries in the eight asymptomatic patients did not show particular findings and they remained clinically and radiologically silent during the follow-up period. All of the lesions in the five symptomatic patients gradually grew to fantastic sizes, with progressive deterioration of the related clinical symptoms. Dilation of the basilar artery was consistent with hemorrhage into the “pseudolumen” within the laminated thrombus, which was confirmed by MR imaging studies. Of the five symptomatic patients studied, two died of fatal subarachnoid hemorrhage (SAH) and two of brainstem compression; the fifth patient remains alive without neurological deficits. In the three patients who underwent autopsy, a definite macroscopic double lumen was observed in both the proximal and distal ends of the aneurysms within the layer of the thickening intima. Microscopically, multiple mural dissections, fragmentation of internal elastic lamina (IEL), and degeneration of media were diffusely observed in the remarkably extended wall of the aneurysms. The substantial mechanism of pathogenesis and enlargement in the symptomatic, highly tortuous dilated artery might initially be macroscopic dissection within a thickening intima and subsequent repetitive hemorrhaging within a laminated thrombus in the pseudolumen combined with microscopic multiple mural dissections on the basis of a weakened IEL. The authors note and caution that symptomatic, tortuous dilated basilar arteries cannot be overlooked because they include a group of malignant arteries that may grow rapidly, resulting in a fatal course.

Transluminal angioplasty for atherosclerotic disease of the vertebral and basilar arteries

1993 ◽  
Vol 78 (2) ◽  
pp. 192-198 ◽  
Author(s):  
Randall T. Higashida ◽  
Fong Y. Tsai ◽  
Van V. Halbach ◽  
Christopher F. Dowd ◽  
Tony Smith ◽  
...  
Keyword(s):  
Vertebral Artery ◽  
Basilar Artery ◽  
Cerebral Circulation ◽  
Transluminal Angioplasty ◽  
Content Type ◽  
Atherosclerotic Stenosis ◽  
Basilar Arteries ◽  
Posterior Cerebral Circulation ◽  
Fine Print

✓ Transluminal angioplasty for hemodynamically significant stenosis (> 70%) involving the posterior cerebral circulation is now being performed by the authors in selected cases. A total of 42 lesions affecting the vertebral or basilar artery have been successfully treated by percutaneous transluminal angioplasty techniques in 41 patients. The lesions involved the proximal vertebral artery in 34 cases, the distal vertebral artery in five, and the basilar artery in three. Patients were examined clinically at 1 to 3 and 6 to 12 months after angioplasty. Three (7.1%) permanent complications occurred, consisting of stroke in two cases and vessel rupture in one. There were four (9.5%) transient complications (< 30 minutes): two cases of vessel spasm and two of cerebral ischemia. Clinical follow-up examination demonstrated improvement of symptoms in 39 cases (92.9%). Radiographic follow-up studies demonstrated three cases (7.1 %) of restenosis involving the proximal vertebral artery; two were treated by repeat angioplasty without complication, and the third is being followed clinically while the patient remains asymptomatic. In patients with significant atherosclerotic stenosis involving the vertebral or basilar artery territories, transluminal angioplasty may be of significant benefit in alleviating symptoms and improving blood flow to the posterior cerebral circulation.

Primary eosinophilic granuloma of the oculomotor nerve

1994 ◽  
Vol 81 (5) ◽  
pp. 784-787 ◽  
Author(s):  
Markus Hardenack ◽  
Anje Völker ◽  
J. Michael Schröder ◽  
Joachim M. Gilsbach ◽  
Albrecht G. Harders
Keyword(s):  
Differential Diagnosis ◽  
Eosinophilic Granuloma ◽  
Cranial Nerves ◽  
Oculomotor Nerve ◽  
Content Type ◽  
Osseous Involvement ◽  
Fine Print

The authors report the occurrence of primary eosinophilic granuloma of the oculomotor nerve without osseous involvement in a 68-year-old man. Histopathological and neuroradiological findings are discussed. This case demonstrates that eosinophilic granuloma should be included in the differential diagnosis of tumor in which cranial nerves are involved.

Upper basilar artery aneurysms: oculomotor outcomes in 163 cases

2005 ◽  
Vol 102 (3) ◽  
pp. 482-488 ◽  
Author(s):  
Hisham Al-Khayat ◽  
Haitham Al-Khayat ◽  
Jonathan White ◽  
David Manner ◽  
Duke Samson
Keyword(s):  
Basilar Artery ◽  
Nerve Palsy ◽  
Arterial Occlusion ◽  
Oculomotor Nerve ◽  
Oculomotor Nerve Palsy ◽  
Stepwise Logistic Regression ◽  
Categorical Data Analysis ◽  
Content Type ◽  
History Of ◽  
Fine Print

Object. The purpose of this study was to identify factors predictive of postoperative oculomotor nerve palsy among patients who undergo surgery for distal basilar artery (BA) aneurysms. The data can be used to estimate preoperative risk in this population. The natural history of oculomotor nerve palsy in patients with good outcomes is also defined. Methods. The cases of 163 patients with distal BA aneurysms, who were treated surgically between 1996 and 2002, were retrospectively studied to identify factors contributing to oculomotor nerve palsy. After the data had been collected, stepwise logistic regression procedures were used to determine the predictive effects of each variable on the development of oculomotor nerve palsy and to create a scoring system. Factors that interfered with resolution of oculomotor dysfunction in patients with good outcomes were also studied. Postoperative oculomotor nerve palsy occurred in 86 patients (52.8%) with distal BA aneurysms. The following factors were associated with postoperative oculomotor dysfunction, as determined by a categorical data analysis: 1) younger patient age (p < 0.001); 2) poor admission Hunt and Hess grade (p < 0.001); 3) use of temporary arterial occlusion (p < 0.001); 4) poor Glasgow Outcome Scale score (p < 0.001); and 5) the presence of a BA apex aneurysm that projected posteriorly (p < 0.001). For patients with good outcomes, postoperative oculomotor nerve palsy resolved completely within 3 months in 31 patients (52%) and within 6 months in 47 patients (80%). The projection of the BA aneurysm was associated with incomplete oculomotor recovery at 6 months postoperatively (p = 0.019). Conclusions. The results of this study can help identify patients with a high risk for the development of oculomotor nerve palsy. This may help neurosurgeons in preoperative planning and discussions.

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