Corrigendum to “Thrombectomy and Clip Occlusion of a Giant, Stent-Coiled Basilar Bifurcation Aneurysm: 3-Dimensional Operative Video” by Fabio A Frisoli, MD, Joshua S Catapano, MD, S Harrison Farber, MD, Jacob F Baranoski, MD, Rohin Singh, BS, Arnau Benet, MD, PhD, Tyler S Cole, MD, Michael A Mooney, MD, and Michael T Lawton, MD. Operative Neurosurgery, Volume 21, Issue 2, August 2021, Pages E117–118, https://doi.org/10.1093/ons/opab108

2021 ◽  
Keyword(s):  
3 Dimensional ◽  
Bifurcation Aneurysm ◽  
Clip Occlusion ◽  
Operative Neurosurgery

Thrombectomy and Clip Occlusion of a Giant, Stent-Coiled Basilar Bifurcation Aneurysm: 3-Dimensional Operative Video

2021 ◽  
Author(s):  
Fabio A Frisoli ◽  
Joshua S Catapano ◽  
S Harrison Farber ◽  
Jacob F Baranoski ◽  
Rohin Singh ◽  
...  
Keyword(s):  
Circulatory Arrest ◽  
Ventricular Pacing ◽  
Indocyanine Green Videoangiography ◽  
Aneurysm Neck ◽  
3 Dimensional ◽  
Bifurcation Aneurysm ◽  
Patient Consent ◽  
Rapid Ventricular Pacing ◽  
Proximal Occlusion ◽  
Clip Occlusion

Abstract Giant basilar apex aneurysms are associated with significant therapeutic challenges.1–6 Multiple techniques exist to treat giant basilar apex aneurysms, including direct clipping, stent-assisted coil embolization, and proximal occlusion with bypass revascularization.7–9 Hypothermic circulatory arrest was a useful adjunct for surgical repair of these aneurysms but has been abandoned because of associated risks.10,11 Rapid ventricular pacing can achieve similar aneurysm softening with minimal risks and assist in clip occlusion. This case illustrates clip occlusion of a giant, partially thrombosed, previously stent-coiled basilar apex aneurysm in a 15-yr-old boy with progressive cranial neuropathies and sensorimotor impairment. Although a wire was placed preoperatively for ventricular pacing, it was not needed during the procedure. Patient consent was obtained. A right-sided orbitozygomatic craniotomy transcavernous approach with anterior and posterior clinoidectomies was performed. The basilar quadrification was dissected, and proximal control was obtained. After aneurysm trapping, the aneurysm was incised and thrombectomized using an ultrasonic aspirator. Back-bleeding from the aneurysm was anticipated, and ventricular pacing was ready, but back-bleeding was minimal. With the coil mass left in place, stacked, fenestrated clips were applied in a tandem fashion to occlude the aneurysm neck. Indocyanine green videoangiography confirmed occlusion of the aneurysm and patency of parent and branch arteries. The patient was at a neurological baseline after the operation, with improvement in motor skills and cognition at 3-mo follow-up. This case demonstrates the use of trans-sylvian-transcavernous exposure, rapid ventricular pacing, and thrombectomy amid previous coils and stents to clip a giant, thrombotic basilar apex aneurysm. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

scholarly journals Left Modified Orbitozygomatic Approach for Clipping of Multilobulated Middle Cerebral Artery Bifurcation Aneurysm: 2-Dimensional Operative Video

2020 ◽  
Vol 19 (4) ◽  
pp. E386-E386 ◽  
Author(s):  
Benjamin K Hendricks ◽  
Robert F Spetzler
Keyword(s):  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Video Recording ◽  
Parent Vessel ◽  
Microsurgical Treatment ◽  
Institutional Review ◽  
Bifurcation Aneurysm ◽  
Orbitozygomatic Approach ◽  
Clip Application ◽  
Clip Occlusion

Abstract Middle cerebral artery (MCA) aneurysms are associated with one of the most favorable approaches for microsurgical treatment; however, aneurysm geometrics can pose challenges during clip application. The surgeon must be mindful of the clip configuration options available during the planning of ideal clip occlusion for irregular or multilobulated aneurysm domes. This patient had an incidental multilobulated MCA bifurcation aneurysm and underwent an orbitozygomatic approach for microsurgical treatment. Proximal and distal control of the aneurysm were achieved, and complete clip occlusion was achieved following the placement of a single permanent clip. Flow within the parent vessel was well preserved, and complete aneurysm occlusion was achieved. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Surgical Resection of a Complex Spetzler-Martin Grade IV Medial Sylvian Arteriovenous Malformation: 3-Dimensional Operative Video

2019 ◽  
Vol 19 (1) ◽  
pp. E60-E60
Author(s):  
Amrit K Chiluwal ◽  
Georgios Klironomos ◽  
Amir R Dehdashti
Keyword(s):  
Surgical Resection ◽  
Video Clip ◽  
Sylvian Fissure ◽  
Complete Excision ◽  
3 Dimensional ◽  
Bifurcation Aneurysm ◽  
Close Proximity ◽  
Complete Obliteration ◽  
Martin Grade

Abstract Sylvian arteriovenous malformations (AVMs) are challenging lesions for surgical management. They are classified according to the Sugita classification based on the location of the nidus in the sylvian fissure: pure, lateral, medial, and deep. Resection of these lesions are fraught with risks, as it requires extensive arachnoid dissection in the sylvian fissure in close proximity to surrounding eloquent tissue, and the presence of en passage arteries can resemble feeding arteries. In this video illustration, the authors describe a complex, Spetzler-Martin Grade IV right sylvian AVM and its surgical resection. By Sugita classification, this was a medial sylvian AVM, with an associated flow related middle cerebral artery (MCA) bifurcation aneurysm. Informed consent was obtained from the patient prior to the procedures. The AVM was embolized preoperatively, and surgical resection was carried out via a pterional approach. The detail of the AVM resection is described in the video clip. Postoperative digital subtraction angiography showed complete excision of the lesion, and the patient was discharged to home on postoperative day 6 without any neurological deficit. In 1-yr follow-up angiogram, beside complete obliteration of the AVM, the flow-related MCA bifurcation aneurysm as well as the M1 and M2 vessels have decreased in size and are much less prominent in comparison to the pretreatment angiography.

Microsurgical Clip Ligation of an Unruptured Azygos Bifurcation Aneurysm Indented by the Falx Cerebri: 3-Dimensional Operative Video

2020 ◽  
Vol 19 (3) ◽  
pp. E294-E294
Author(s):  
Blake E S Taylor ◽  
Irene Say ◽  
Pratit Patel ◽  
Luke D Tomycz
Keyword(s):  
Surgical Techniques ◽  
Smoking History ◽  
Falx Cerebri ◽  
Anatomical Variant ◽  
3 Dimensional ◽  
Bifurcation Aneurysm ◽  
Vessel Injury ◽  
History Of ◽  
Rare Anatomic Variant ◽  
Intraoperative Rupture

Abstract Dissecting pericallosal aneurysms from the falx cerebri is technically challenging, as one must release the adherent dome but minimize shearing injury, which could result in intraoperative rupture. We discuss a 51-yr-old woman with a history of hypertension and smoking who presented with severe headaches and was found to have a 6-mm unruptured, multilobulated pericallosal aneurysm abutting the falx, with anterior and superior projecting domes on either side. She also had an azygos anterior cerebral artery (ACA), a rare anatomic variant associated with pericallosal aneurysms, where both A1 segments form a single A2. After considering endovascular and open surgical techniques, we proceeded with clip ligation given her younger age, smoking history, daughter aneurysms seen on angiography, and azygos ACA. We positioned her supine with her head turned lateral, left side down to maximize gravitational retraction, mapped a bicoronal incision, and performed a small craniotomy, followed by an interhemispheric approach. Rather than cutting the falx around the dome, a described technique that risks blind vessel injury, we temporarily clipped inflow vessels to reduce the dome's turgor and sharply and bluntly dissected apart its attachments, which freed the aneurysm from beneath the falx and allowed visualization of associated vessels. Using suction to manipulate the dome, we then placed stacked, angled clips, and used a micro-Doppler to confirm brisk inflow and outflow. Postoperatively, she was neurologically intact, and her angiogram showed no residual aneurysm. Our 3-dimensional video demonstrates a safer, alternative approach to treating this rare aneurysm with its associated anatomical variant. Patient consented to her clinical presentation and microscope media being used for academic purposes.

Three-Dimensional Reconstruction Using Stereo Pairs from Serial Thick Sections

1977 ◽  
Vol 35 ◽  
pp. 562-563
Author(s):  
Robert Glaeser ◽  
Thomas Bauer ◽  
David Grano
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
Serial Sections ◽  
Thin Sections ◽  
3 Dimensional ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Dimensional Reconstruction ◽  
Stereo Imagery ◽  
Whole Mounts

In transmission electron microscopy, the 3-dimensional structure of an object is usually obtained in one of two ways. For objects which can be included in one specimen, as for example with elements included in freeze- dried whole mounts and examined with a high voltage microscope, stereo pairs can be obtained which exhibit the 3-D structure of the element. For objects which can not be included in one specimen, the 3-D shape is obtained by reconstruction from serial sections. However, without stereo imagery, only detail which remains constant within the thickness of the section can be used in the reconstruction; consequently, the choice is between a low resolution reconstruction using a few thick sections and a better resolution reconstruction using many thin sections, generally a tedious chore. This paper describes an approach to 3-D reconstruction which uses stereo images of serial thick sections to reconstruct an object including detail which changes within the depth of an individual thick section.

Structural preservation and absolute contrast of catalase crystal sections prepared with tannic acid

1983 ◽  
Vol 41 ◽  
pp. 448-449
Author(s):  
C.W. Akey ◽  
M. Szalay ◽  
S.J. Edelstein
Keyword(s):  
Tannic Acid ◽  
Beef Heart ◽  
X Rays ◽  
Screw Axis ◽  
General Applicability ◽  
Thin Sections ◽  
Beef Liver ◽  
3 Dimensional ◽  
Dimensional Reconstruction ◽  
Structural Preservation

Three methods of obtaining 20 Å resolution in sectioned protein crystals have recently been described. They include tannic acid fixation, low temperature embedding and grid sectioning. To be useful for 3-dimensional reconstruction thin sections must possess suitable resolution, structural fidelity and a known contrast. Tannic acid fixation appears to satisfy the above criteria based on studies of crystals of Pseudomonas cytochrome oxidase, orthorhombic beef liver catalase and beef heart F1-ATPase. In order to develop methods with general applicability, we have concentrated our efforts on a trigonal modification of catalase which routinely demonstrated a resolution of 40 Å. The catalase system is particularly useful since a comparison with the structure recently solved with x-rays will permit evaluation of the accuracy of 3-D reconstructions of sectioned crystals.Initially, we re-evaluated the packing of trigonal catalase crystals studied by Longley. Images of the (001) plane are of particular interest since they give a projection down the 31-screw axis in space group P3121. Images obtained by the method of Longley or by tannic acid fixation are negatively contrasted since control experiments with orthorhombic catalase plates yield negatively stained specimens with conditions used for the larger trigonal crystals.

Deviations from Ideal Decagonal Symmetry in Electron Diffraction Patterns of the “Decagonal” Phase in the Al-Co-Cu Alloy System

1991 ◽  
Vol 49 ◽  
pp. 914-915
Author(s):  
Atul S. Ramani ◽  
Earle R. Ryba ◽  
Paul R. Howell
Keyword(s):  
Electron Microscope ◽  
Alloy System ◽  
Nominal Composition ◽  
Dimensional Lattice ◽  
3 Dimensional ◽  
Decagonal Phase ◽  
Cu Alloy ◽  
Transmission Electron ◽  
Lattice Periodicity ◽  
Diffraction Patterns

The “decagonal” phase in the Al-Co-Cu system of nominal composition Al65CO15Cu20 first discovered by He et al. is especially suitable as a topic of investigation since it has been claimed that it is thermodynamically stable and is reported to be periodic in the dimension perpendicular to the plane of quasiperiodic 10-fold symmetry. It can thus be expected that it is an important link between fully periodic and fully quasiperiodic phases. In the present paper, we report important findings of our transmission electron microscope (TEM) study that concern deviations from ideal decagonal symmetry of selected area diffraction patterns (SADPs) obtained from several “decagonal” phase crystals and also observation of a lattice of main reflections on the 10-fold and 2-fold SADPs that implies complete 3-dimensional lattice periodicity and the fundamentally incommensurate nature of the “decagonal” phase. We also present diffraction evidence for a new transition phase that can be classified as being one-dimensionally quasiperiodic if the lattice of main reflections is ignored.

A Novel Reconstitution Method for Inducing the Formation of Regular 2-Dimensional Arrays of Membrane Proteins and Lipids

1988 ◽  
Vol 46 ◽  
pp. 152-153 ◽  
Author(s):  
A. Engel ◽  
A. Holzenburg ◽  
K. Stauffer ◽  
J. Rosenbusch ◽  
U. Aebi
Keyword(s):  
Membrane Proteins ◽  
Flow Rate ◽  
Lipid Membranes ◽  
Functional Characterization ◽  
Dimensional Structure ◽  
Electron Crystallography ◽  
Peltier Element ◽  
Protein Ratio ◽  
Precise Control ◽  
3 Dimensional

Reconstitution of solubilized and purified membrane proteins in the presence of phospholipids into vesicles allows their functions to be studied by simple bulk measurements (e.g. diffusion of differently sized solutes) or by conductance measurements after transformation into planar membranes. On the other hand, reconstitution into regular protein-lipid arrays, usually forming at a specific lipid-to-protein ratio, provides the basis for determining the 3-dimensional structure of membrane proteins employing the tools of electron crystallography.To refine reconstitution conditions for reproducibly inducing formation of large and highly ordered protein-lipid membranes that are suitable for both electron crystallography and patch clamping experiments aimed at their functional characterization, we built a flow-dialysis device that allows precise control of temperature and flow-rate (Fig. 1). The flow rate is generated by a peristaltic pump and can be adjusted from 1 to 500 ml/h. The dialysis buffer is brought to a preselected temperature during its travel through a meandering path before it enters the dialysis reservoir. A Z-80 based computer controls a Peltier element allowing the temperature profile to be programmed as function of time.

Structure and Interaction of Protamine by Dark Field Electron Microscopy

1976 ◽  
Vol 34 ◽  
pp. 160-161
Author(s):  
D.P. Bazett-Jones ◽  
F.P. Ottensmeyer
Keyword(s):  
Electron Microscopy ◽  
Dark Field ◽  
Amino Acid Sequences ◽  
Dimensional Structure ◽  
3 Dimensional ◽  
Field Electron ◽  
Proposed Model ◽  
Field Electron Microscopy ◽  
Dark Field Electron ◽  
Positively Charged

It has been shown for some time that it is possible to obtain images of small unstained proteins, with a resolution of approximately 5Å using dark field electron microscopy (1,2). Applying this technique, we have observed a uniformity in size and shape of the 2-dimensional images of pure specimens of fish protamines (salmon, herring (clupeine, Y-l) and rainbow trout (Salmo irideus)). On the basis of these images, a model for the 3-dimensional structure of the fish protamines has been proposed (2).The known amino acid sequences of fish protamines show stretches of positively charged arginines, separated by regions of neutral amino acids (3). The proposed model for protamine structure (2) consists of an irregular, right-handed helix with the segments of adjacent arginines forming the loops of the coil.

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