Quantification of increased exposure resulting from orbital rim and orbitozygomatic osteotomy via the frontotemporal transsylvian approach

1999 ◽  
Vol 91 (6) ◽  
pp. 1020-1026 ◽  
Author(s):  
Marc S. Schwartz ◽  
Gregory J. Anderson ◽  
Michael A. Horgan ◽  
Jordi X. Kellogg ◽  
Sean O. McMenomey ◽  
...  
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Zygomatic Arch ◽  
Neurosurgical Procedures ◽  
Content Type ◽  
Transsylvian Approach ◽  
Surgical Access ◽  
Stereotactic Device ◽  
Orbital Rim ◽  
Fine Print

Object. Use of orbital rim and orbitozygomatic osteotomy has been extensively reported to increase exposure in neurosurgical procedures. However, there have been few attempts to quantify the extent of additional exposure gained by these maneuvers. Using a novel laboratory technique, the authors have attempted to measure the increase in the “area of exposure” that is gained by removal of the orbital rim and zygomatic arch via the frontotemporal transsylvian approach.Methods. The authors dissected five cadavers bilaterally. The area of exposure provided by the frontotemporal transsylvian approach was determined by using a frameless stereotactic device. With the tip of a microdissector placed on targets deep within the exposure, the position of the end of the microdissector handle was measured in three-dimensional space as the microdissector was rotated around the periphery of the operative field. This maneuver was performed via the frontotemporal approach alone as well as with orbital rim and orbitozygomatic osteotomy approaches. After data manipulation, the areas of exposure corresponding to the polygons used to define these handle positions were calculated and directly compared. On average, the area of exposure provided by the frontotemporal transsylvian approach was increased 26 to 39% (p < 0.05) by adding orbital rim osteotomy and an additional 13 to 22% (not significant) with removal of the zygomatic arch.Conclusions. Significant and consistent increases in surgical exposure were obtained by using orbital osteotomy, whereas zygomatic arch removal produced less consistent gains. Both maneuvers may be expected to improve surgical access. However, because larger and more consistent gains were afforded by orbital rim removal, the threshold for removal of this portion of the orbitozygomatic complex should be lower.

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.

Preservation of large bridging veins during brain retraction

1982 ◽  
Vol 57 (6) ◽  
pp. 856-858 ◽  
Author(s):  
Kenichiro Sugita ◽  
Shigeaki Kobayashi ◽  
Akiro Yokoo
Keyword(s):  
Postoperative Morbidity ◽  
Neurosurgical Procedures ◽  
Content Type ◽  
Transsylvian Approach ◽  
Bridging Veins ◽  
Brain Retraction ◽  
Fine Print

✓ The authors describe a method for preserving large bridging veins during neurosurgical procedures by stripping them from the cortex. This technique was used in 81 procedures involving a subtemporal, interhemispheric, infratentorial supracerebellar, and transsylvian approach. Although a small amount of the cortex was often sacrificed, preservation of the vein was easy, and postoperative morbidity was minimized.

Intraoperative stereoscopic QuickTime Virtual Reality

2004 ◽  
Vol 100 (4) ◽  
pp. 591-596 ◽  
Author(s):  
Attila Balogh ◽  
Mark C. Preul ◽  
Mark Schornak ◽  
Michael Hickman ◽  
Robert F. Spetzler
Keyword(s):  
Virtual Reality ◽  
Image Acquisition ◽  
Three Dimensional ◽  
Neurosurgical Procedures ◽  
Digital Cameras ◽  
Content Type ◽  
Left And Right ◽  
Software And Hardware ◽  
Image Pairs ◽  
Fine Print

Object. The aim of this study was to acquire intraoperative images during neurosurgical procedures for later reconstruction into a stereoscopic image system (QuickTime Virtual Reality [QTVR]) that would improve visualization of complex neurosurgical procedures. Methods. A robotic microscope and digital cameras were used to acquire left and right image pairs during cranial surgery; a grid system facilitated image acquisition with the microscope. The surgeon determined a field of interest and a target or pivot point for image acquisition. Images were processed with commercially available software and hardware. Two-dimensional (2D) or interlaced left and right 2D images were reconstructed into a standard or stereoscopic QTVR format. Standard QTVR images were produced if stereoscopy was not needed. Intraoperative image sequences of regions of interest were captured in six patients. Relatively wide and deep dissections afford an opportunity for excellent QTVR production. Narrow or restricted surgical corridors can be reconstructed into the stereoscopic QTVR mode by using a keyhole mode of image acquisition. The stereoscopic effect is unimpressive with shallow or cortical surface dissections, which can be reconstructed into standard QTVR images. Conclusions. The QTVR system depicts multiple views of the same anatomy from different angles. By tilting, panning, or rotating the reconstructed images, the user can view a virtual three-dimensional tour of a neurosurgical dissection, with images acquired intraoperatively. The stereoscopic QTVR format provides depth to the montage. The system recreates the dissection environment almost completely and provides a superior anatomical frame of reference compared with the images captured by still or video photography in the operating room.

Clinical application of robotic telemanipulation system in neurosurgery

2003 ◽  
Vol 99 (6) ◽  
pp. 1082-1084 ◽  
Author(s):  
Tetsuya Goto ◽  
Kazuhiro Hongo ◽  
Yukinari Kakizawa ◽  
Hisashi Muraoka ◽  
Yosuke Miyairi ◽  
...  
Keyword(s):  
Case Report ◽  
Clinical Application ◽  
Microscopic Observation ◽  
Direct Contact ◽  
Three Dimensional ◽  
Neurosurgical Procedures ◽  
Content Type ◽  
Postoperative Course ◽  
First Case ◽  
Fine Print

✓ The NeuRobot is a telecontrolled microscopic micromanipulator system designed for neurosurgical procedures. The unit houses a three-dimensional endoscope and three robot arms that the surgeon operates without direct contact with the patient. The authors have successfully performed robotics-assisted neurosurgical procedures by using the NeuRobot in a 54-year-old man who had a recurrent atypical meningioma. Following the usual preparation of craniotomy and opening of the dura mater, a portion of the tumor was removed using the NeuRobot with the aid of microscopic observation. No complication related to the use of the NeuRobot was encountered and the patient's postoperative course was uneventful. Although various kinds of robots have been developed for use in neurosurgery in recent years, a robotic telemanipulation system capable of performing several surgical tasks has not previously been introduced to clinical neurosurgery. This is the first case report in which neurosurgical manipulation by a robotics system is described.

Stereotactic radiosurgery versus stereotactic radiotherapy for patients with vestibular schwannoma: a Leksell Gamma Knife Society 2000 debate

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 90-92 ◽  
Author(s):  
Mark E. Linskey
Keyword(s):  
Gamma Knife ◽  
Stereotactic Radiotherapy ◽  
Three Dimensional ◽  
Late Recurrence ◽  
Vestibular Schwannomas ◽  
Tumor Control ◽  
Complication Rates ◽  
Content Type ◽  
Single Fraction ◽  
Fine Print

✓ By definition, the term “radiosurgery” refers to the delivery of a therapeutic radiation dose in a single fraction, not simply the use of stereotaxy. Multiple-fraction delivery is better termed “stereotactic radiotherapy.” There are compelling radiobiological principles supporting the biological superiority of single-fraction radiation for achieving an optimal therapeutic response for the slowly proliferating, late-responding, tissue of a schwannoma. It is axiomatic that complication avoidance requires precise three-dimensional conformality between treatment and tumor volumes. This degree of conformality can only be achieved through complex multiisocenter planning. Alternative radiosurgery devices are generally limited to delivering one to four isocenters in a single treatment session. Although they can reproduce dose plans similar in conformality to early gamma knife dose plans by using a similar number of isocenters, they cannot reproduce the conformality of modern gamma knife plans based on magnetic resonance image—targeted localization and five to 30 isocenters. A disturbing trend is developing in which institutions without nongamma knife radiosurgery (GKS) centers are championing and/or shifting to hypofractionated stereotactic radiotherapy for vestibular schwannomas. This trend appears to be driven by a desire to reduce complication rates to compete with modern GKS results by using complex multiisocenter planning. Aggressive advertising and marketing from some of these centers even paradoxically suggests biological superiority of hypofractionation approaches over single-dose radiosurgery for vestibular schwannomas. At the same time these centers continue to use the term radiosurgery to describe their hypofractionated radiotherapy approach in an apparent effort to benefit from a GKS “halo effect.” It must be reemphasized that as neurosurgeons our primary duty is to achieve permanent tumor control for our patients and not to eliminate complications at the expense of potential late recurrence. The answer to minimizing complications while maintaining maximum tumor control is improved conformality of radiosurgery dose planning and not resorting to homeopathic radiosurgery doses or hypofractionation radiotherapy schemes.

Biomechanical characteristics of C1–2 cable fixations

1996 ◽  
Vol 85 (2) ◽  
pp. 316-322 ◽  
Author(s):  
Curtis A. Dickman ◽  
Neil R. Crawford ◽  
Christopher G. Paramore
Keyword(s):  
Cyclic Loading ◽  
Translational Motion ◽  
Biomechanical Testing ◽  
Three Dimensional ◽  
Constrained Motion ◽  
Content Type ◽  
Physiological Range ◽  
Fixation Techniques ◽  
Cable Fixation ◽  
Fine Print

✓ The biomechanical characteristics of four different methods of C1–2 cable fixation were studied to assess the effectiveness of each technique in restoring atlantoaxial stability. Biomechanical testing was performed on the upper cervical spines of four human cadaveric specimens. Physiological range loading was applied to the atlantoaxial specimens and three-dimensional motion was analyzed with stereophotogrammetry. The load–deformation relationships and kinematics were measured, including the stiffness, the angular ranges of motion, the linear ranges of motion, and the axes of rotation. Specimens were nondestructively tested in the intact state, after surgical destabilization, and after each of four different methods of cable fixation. Cable fixation techniques included the interspinous technique, the Brooks technique, and two variants of the Gallie technique. All specimens were tested immediately after fixation and again after the specimen was fatigued with 6000 cycles of physiological range torsional loading. All four cable fixation methods were moderately flexible immediately; the different cable fixations allowed between 5° and 40° of rotational motion and between 0.6 and 7 mm of translational motion to occur at C1–2. The Brooks and interspinous methods controlled C1–2 motion significantly better than both of the Gallie techniques. The motion allowed by one of the Gallie techniques did not differ significantly from the motion of the unfixed destabilized specimens. All cable fixation techniques loosened after cyclic loading and demonstrated significant increases in C1–2 rotational and translational motions. The bone grafts shifted during cyclic loading, which reduced the effectiveness of the fixation. The locations of the axes of rotation, which were unconstrained and mobile in the destabilized specimens, became altered with cable fixation. The C1–2 cables constrained motion by shifting the axes of rotation so that C-1 rotated around the fixed cable and graft site. After the specimen was fatigued, the axes of rotation became more widely dispersed but were usually still localized near the cable and graft site. Adequate healing requires satisfactory control of C1–2 motion. Therefore, some adjunctive fixation is advocated to supplement the control of motion after C1–2 cable fixation (that is, a cervical collar, a halo brace, or rigid internal fixation with transarticular screws).

Cerebral hemorrhage and edema following brain biopsy in rats: significance of mean arterial blood pressure

2000 ◽  
Vol 92 (1) ◽  
pp. 100-107 ◽  
Author(s):  
Helene Benveniste ◽  
Katie R. Kim ◽  
Laurence W. Hedlund ◽  
John W. Kim ◽  
Allan H. Friedman
Keyword(s):  
Blood Pressure ◽  
Arterial Blood Pressure ◽  
Mean Arterial Blood Pressure ◽  
Neurosurgical Procedures ◽  
Shr Rats ◽  
Mr Microscopy ◽  
Content Type ◽  
Wky Rats ◽  
Arterial Blood ◽  
Fine Print

Object. It is taken for granted that patients with hypertension are at greater risk for intracerebral hemorrhage during neurosurgical procedures than patients with normal blood pressure. The anesthesiologist, therefore, maintains mean arterial blood pressure (MABP) near the lower end of the autoregulation curve, which in patients with preexisting hypertension can be as high as 110 to 130 mm Hg. Whether patients with long-standing hypertension experience more hemorrhage than normotensive patients after brain surgery if their blood pressure is maintained at the presurgical hypertensive level is currently unknown. The authors tested this hypothesis experimentally in a rodent model.Methods. Hemorrhage and edema in the brain after needle biopsy was measured in vivo by using three-dimensional magnetic resonance (MR) microscopy in the following groups: WKY rats, acutely hypertensive WKY rats, spontaneously hypertensive rats (SHR strain), and SHR rats treated with either sodium nitroprusside or nicardipine. Group differences were compared using Tukey's studentized range test followed by individual pairwise comparisons of groups and adjusted for multiple comparisons.There were no differences in PaCO2, pH, and body temperature among the groups. The findings in this study indicated that only acutely hypertensive WKY rats had larger volumes of hemorrhage. Chronically hypertensive SHR rats with MABPs of 130 mm Hg did not have larger hemorrhages than normotensive rats. There were no differences in edema volumes among groups.Conclusions. The brains of SHR rats with elevated systemic MABPs are probably protected against excessive hemorrhage during surgery because of greater resistance in the larger cerebral arteries and, thus, reduced cerebral intravascular pressures.

Intraoperative angiography in the resection of arteriovenous malformations

1994 ◽  
Vol 80 (1) ◽  
pp. 73-78 ◽  
Author(s):  
Shigetaka Anegawa ◽  
Takashi Hayashi ◽  
Ryuichiro Torigoe ◽  
Katsuhiko Harada ◽  
Shun-ichi Kihara
Keyword(s):  
Surgical Resection ◽  
Arteriovenous Malformations ◽  
Three Dimensional ◽  
Initial Operation ◽  
Total Resection ◽  
Intraoperative Angiography ◽  
Content Type ◽  
Fine Print

✓ Surgical resection of 13 operatively obscure arteriovenous malformations (AVM's) was accomplished with the assistance of intraoperative angiography, which was performed stereographically to provide three-dimensional orientation and was repeated until total resection of the AVM was confirmed. All films obtained were subtracted to improve clarity. The method presented here may be useful for the resection of all types of AVM. Only two patients had residual AVM after the initial operation. No complications attributable to angiography were noted.

scholarly journals Intra- and Interspecies Variability of Single-Cell Innate Fluorescence Signature of Microbial Cell

2019 ◽  
Vol 85 (18) ◽  
Author(s):  
Yutaka Yawata ◽  
Tatsunori Kiyokawa ◽  
Yuhki Kawamura ◽  
Tomohiro Hirayama ◽  
Kyosuke Takabe ◽  
...  
Keyword(s):  
Single Cell ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Population Level ◽  
Microbial Cell ◽  
Physiological Status ◽  
Growth Phases ◽  
Content Type ◽  
A Cell ◽  
Three Dimensional Space

ABSTRACT Here we analyzed the innate fluorescence signature of the single microbial cell, within both clonal and mixed populations of microorganisms. We found that even very similarly shaped cells differ noticeably in their autofluorescence features and that the innate fluorescence signatures change dynamically with growth phases. We demonstrated that machine learning models can be trained with a data set of single-cell innate fluorescence signatures to annotate cells according to their phenotypes and physiological status, for example, distinguishing a wild-type Aspergillus nidulans cell from its nitrogen metabolism mutant counterpart and log-phase cells from stationary-phase cells of Pseudomonas putida. We developed a minimally invasive method (confocal reflection microscopy-assisted single-cell innate fluorescence [CRIF] analysis) to optically extract and catalog the innate cellular fluorescence signatures of each of the individual live microbial cells in a three-dimensional space. This technique represents a step forward from traditional techniques which analyze the innate fluorescence signatures at the population level and necessitate a clonal culture. Since the fluorescence signature is an innate property of a cell, our technique allows the prediction of the types or physiological status of intact and tag-free single cells, within a cell population distributed in a three-dimensional space. Our study presents a blueprint for a streamlined cell analysis where one can directly assess the potential phenotype of each single cell in a heterogenous population by its autofluorescence signature under a microscope, without cell tagging. IMPORTANCE A cell’s innate fluorescence signature is an assemblage of fluorescence signals emitted by diverse biomolecules within a cell. It is known that the innate fluoresce signature reflects various cellular properties and physiological statuses; thus, they can serve as a rich source of information in cell characterization as well as cell identification. However, conventional techniques focus on the analysis of the innate fluorescence signatures at the population level but not at the single-cell level and thus necessitate a clonal culture. In the present study, we developed a technique to analyze the innate fluorescence signature of a single microbial cell. Using this novel method, we found that even very similarly shaped cells differ noticeably in their autofluorescence features, and the innate fluorescence signature changes dynamically with growth phases. We also demonstrated that the different cell types can be classified accurately within a mixed population under a microscope at the resolution of a single cell, depending solely on the innate fluorescence signature information. We suggest that single-cell autofluoresce signature analysis is a promising tool to directly assess the taxonomic or physiological heterogeneity within a microbial population, without cell tagging.

Volumetric thermal devascularization of large meningiomas

2004 ◽  
Vol 101 (5) ◽  
pp. 779-786 ◽  
Author(s):  
Amami Kato ◽  
Yasunori Fujimoto ◽  
Masaaki Taniguchi ◽  
Naoya Hashimoto ◽  
Azuma Hirayama ◽  
...  
Keyword(s):  
Thermal Ablation ◽  
Histopathological Examination ◽  
Three Dimensional ◽  
Target Volume ◽  
Coagulation Necrosis ◽  
Radiofrequency Energy ◽  
Content Type ◽  
Dimensional Reconstruction ◽  
Tumor Parenchyma ◽  
Fine Print

Object. Controlling hemorrhage is crucial in the safe and efficient removal of large meningiomas. Intravascular embolization is not always a satisfactory means of accomplishing this goal because of the procedure's hemostatic effect and risk of complications. The authors in this study used a volumetric thermal ablation technique incorporating radiofrequency energy, image guidance, and local temperature control to devascularize tumor tissue. Methods. Five patients with large meningiomas were treated. The target and orientation of the radiofrequency thermal ablation (RFTA) were simulated preoperatively to maximize devascularization of the lesion without thermal injury to adjacent critical structures. Image fusion, three-dimensional reconstruction, and image-guided methods provided for optimized trajectories and targets for insertion of the RFTA needle. During ablation, local temperatures of the tissue being cauterized were monitored continuously to limit the ablated lesion to within the target volume. The effects of devascularization and the softening of the tumor parenchyma facilitated lesion removal. The intracranial ablated meningioma changed into necrotic tissue and shrank within a few months. Histopathological examination of the ablated lesion revealed sharply demarcated coagulation necrosis. Conclusions. Volumetric thermal devascularization can be applied safely in the treatment of large meningiomas to facilitate surgical manipulation of the lesion as well as to reduce its size palliatively. The procedure's usefulness should be studied further in a larger number of cases with different tumor characteristics.

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