Operative Anatomy of the Skull Base: 3D Exploration with a Highly Detailed Interactive Atlas

2021 ◽  
Author(s):  
Ralf A. Kockro ◽  
Eike Schwandt ◽  
Florian Ringel ◽  
Christian Valentin Eisenring ◽  
Wieslaw Lucjan Nowinski
Keyword(s):  
Skull Base ◽  
Clinical Setting ◽  
Cranial Nerves ◽  
Three Dimensional ◽  
Surgical Anatomy ◽  
University Hospital ◽  
Complex Anatomy ◽  
Operative Strategies ◽  
Interactive 3D ◽  
3D Exploration

Abstract Objective We evaluated the usefulness of a three-dimensional (3D) interactive atlas to illustrate and teach surgical skull base anatomy in a clinical setting. Study Design A highly detailed atlas of the adult human skull base was created from multiple high-resolution magnetic resonance imaging (MRI) and computed tomography (CT) scans of a healthy Caucasian male. It includes the parcellated and labeled bony skull base, intra- and extracranial vasculature, cranial nerves, cerebrum, cerebellum, and brainstem. We are reporting retrospectively on our experiences with employing the atlas for the simulation and teaching of neurosurgical approaches and concepts in a clinical setting. Setting The study was conducted at the University Hospital Mainz, Germany, and Hirslanden Hospital, Zürich, Switzerland. Participants Medical students and neurosurgical residents participated in this study. Results Handling the layered graphical user interface of the atlas requires some training; however, navigating the detailed 3D content from intraoperative perspectives led to quick comprehension of anatomical relationships that are otherwise difficult to perceive. Students and residents appreciated the collaborative learning effect when working with the atlas on large projected screens and markedly improved their anatomical knowledge after interacting with the software. Conclusion The skull base atlas provides an effective way to study essential surgical anatomy and to teach operative strategies in this complex region. Interactive 3D computer graphical environments are highly suitable for conveying complex anatomy and to train and review surgical concepts. They remain underutilized in clinical practice.

scholarly journals Magnetic resonance imaging of the cranial nerves in congenital, traumatic, and vascular diseases: a pictorial essay

2021 ◽  
Vol 54 (3) ◽  
pp. 185-192 ◽  
Author(s):  
Mariana Dalaqua ◽  
Felipe Barjud Pereira do Nascimento ◽  
Larissa Kaori Miura ◽  
Fabiano Reis ◽  
Márcio Ricardo Taveira Garcia ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Cranial Nerves ◽  
Three Dimensional ◽  
Vascular Diseases ◽  
Resonance Imaging ◽  
Complex Anatomy ◽  
Contrast Enhanced ◽  
Pictorial Essay ◽  
The Brain

Abstract The cranial nerves, which represent extensions of the functional structures of the brain, traverse the head and neck. They are connected to various cranial structures and are associated with several diseases. An in-depth understanding of their complex anatomy and normal imaging appearance allows the examiner to identify and characterize abnormalities with greater precision. One important tool for evaluating the cranial nerves is contrast-enhanced magnetic resonance imaging, especially three-dimensional steady-state free precession sequences, which provide high soft-tissue and spatial resolution, despite the slenderness of the nerves. In most cases, imaging findings are nonspecific. Therefore, to narrow the differential diagnosis, it is necessary to take a full patient anamnesis, perform a focused physical examination and order laboratory tests. In this pictorial essay we review, illustrate and discuss, from a pathophysiological perspective, congenital, traumatic, and vascular diseases of the cranial nerves.

The Asterion-to-Transverse Process of the Atlas Line as a Surgical Landmark

2021 ◽  
Author(s):  
Jaafar Basma ◽  
Dom E. Mahoney ◽  
Christos Anagnostopoulos ◽  
L. Madison Michael ◽  
Jeffrey M. Sorenson ◽  
...  
Keyword(s):  
Skull Base ◽  
Cranial Nerves ◽  
Three Dimensional ◽  
Transverse Process ◽  
Jugular Foramen ◽  
Foramen Magnum ◽  
Sigmoid Sinus ◽  
Cervical Region ◽  
Surgical Approaches ◽  
Anatomical Location

Abstract Introduction Proposed landmarks to predict the anatomical location and trajectory of the sigmoid sinus have varying degrees of reliability. Even with neuronavigation technology, landmarks are crucial in planning and performing complex approaches to the posterolateral skull base. By combining two major dependable structures—the asterion (A) and transverse process of the atlas (TPC1)—we investigate the A-TPC1 line in relation to the sigmoid sinus and in partitioning surgical approaches to the region. Methods We dissected six cadaveric heads (12 sides) to expose the posterolateral skull base, including the mastoid and suboccipital bone, TPC1 and suboccipital triangle, distal jugular vein and internal carotid artery, and lower cranial nerves in the distal cervical region. We inspected the A-TPC1 line before and after drilling the mastoid and occipital bones and studied the relationship of the sigmoid sinus trajectory and major muscular elements related to the line. We retrospectively reviewed 31 head and neck computed tomography (CT) angiograms (62 total sides), excluding posterior fossa or cervical pathologies. Bone and vessels were reconstructed using three-dimensional segmentation software. We measured the distance between the A-TPC1 line and sigmoid sinus at different levels: posterior digastric point (DP), and maximal distances above and below the digastric notch. Results A-TPC1 length averaged 65 mm and was posterior to the sigmoid sinus in all cadaver specimens, coming closest at the level of the DP. Using the transverse-asterion line as a rostrocaudal division and skull base as a horizontal plane, we divided the major surgical approaches into four quadrants: distal cervical/extreme lateral and jugular foramen (anteroinferior), presigmoid/petrosal (anterosuperior), retrosigmoid/suboccipital (posterosuperior), and far lateral/foramen magnum regions (posteroinferior). Radiographically, the A-TPC1 line was also posterior to the sigmoid sinus in all sides and came closest to the sinus at the level of DP (mean, 7 mm posterior; range, 0–18.7 mm). The maximal distance above the DP had a mean of 10.1 mm (range, 3.6–19.5 mm) and below the DP 5.2 mm (range, 0–20.7 mm). Conclusion The A-TPC1 line is a helpful landmark reliably found posterior to the sigmoid sinus in cadaveric specimens and radiographic CT scans. It can corroborate the accuracy of neuronavigation, assist in minimizing the risk of sigmoid sinus injury, and is a useful tool in planning surgical approaches to the posterolateral skull base, both preoperatively and intraoperatively.

Imaging the Cerebrovascular Tree in the Cadaveric Head for Planning Surgical Strategy

Neurosurgery ◽  
2002 ◽  
Vol 51 (5) ◽  
pp. 1222-1228 ◽  
Author(s):  
Jin-Cheng Zhao ◽  
Chi Chen ◽  
Sami S. Rosenblatt ◽  
Joel R. Meyer ◽  
Robert R. Edelman ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Contrast Agent ◽  
Skull Base ◽  
Surgical Planning ◽  
Soft Tissues ◽  
Three Dimensional ◽  
Surgical Anatomy ◽  
Vascular Lesions ◽  
Preoperative Imaging ◽  
Computed Tomographic

Abstract OBJECTIVE The objective of the study was to identify whether an integration of cadaveric dissections with preoperative imaging information may enable a better understanding of pathological anatomy, especially vascular lesions, and thus allow for greater precision in surgical planning. METHODS We selected a computed tomographic contrast agent and experimentally determined the proportion of it that could mix compatibly with the silicone compound. The resultant mixture was injected into the cerebrovascular systems of six fresh human cadaveric heads. The specimens underwent computed tomography for the purpose of digital virtual exposures in parallel with laboratory dissections performed on these specimens. RESULTS The 1:8 ratio of contrast agent to silicone rubber was determined to be appropriate for both computed tomography and subsequent laboratory dissection of the specimens. The blood vessels in computed tomographic scans demonstrated a higher attenuation than surrounding soft tissues. The opacity consistency of the injected vessels was a critical parameter for a clear three-dimensional rendering of the vascular structures in the natural surroundings of the skull base. Static and dynamic three-dimensional images of the cadaveric vascular tree were obtained as viewed through surgical corridors of various skull base approaches. CONCLUSION We demonstrated a new cadaveric preparation model for imaging and dissection. This model allows for static and dynamic three-dimensional examination of the surgical anatomy from a neurosurgeon's perspective. It may facilitate the study of cerebrovascular system morphology/pathology in relation to the skull base as a tool for surgical planning.

scholarly journals Role of transcranial sphenoidotomy in skull base surgery: classification of surgical techniques based on the surgical anatomy of the sphenoid sinus

2019 ◽  
Vol 131 (5) ◽  
pp. 1658-1667 ◽  
Author(s):  
Kenichiro Iwami ◽  
Masazumi Fujii ◽  
Yugo Kishida ◽  
Shinya Jinguji ◽  
Masayuki Yamada ◽  
...  
Keyword(s):  
Skull Base ◽  
Sphenoid Sinus ◽  
Skull Base Surgery ◽  
En Bloc Resection ◽  
Bloc Resection ◽  
Surgical Anatomy ◽  
University Hospital ◽  
En Bloc ◽  
Cadaveric Dissection ◽  
Medical University

OBJECTIVEAlthough sphenoidotomy is more commonly performed via the transnasal approach than via the transcranial approach, transcranial sphenoidotomy (TCS) remains indispensable for en bloc resection of locally advanced sinonasal malignant tumors (SNMTs) extending to the skull base. TCS also enables transsphenoidal transposition of the temporoparietal galeal flap (TPGF) to compensate for the lack of vascularized reconstructive tissue after endoscopic transnasal skull base surgery. The objective of this study was to review the authors’ surgical experience using TCS with an emphasis on the surgical anatomy of the sphenoid sinus and on the purpose of TCS. Relevant anatomy is further illustrated through cadaveric dissection and photo documentation.METHODSThe authors reviewed the records of 50 patients who underwent TCS at the Nagoya University Hospital, Fukushima Medical University Hospital, or Aichi Medical University Hospital over the course of 7 years (between January 2011 and November 2017). The authors also performed cadaveric dissection in 2 adult cadaveric skull base specimens.RESULTSOf the 50 patients included in this study, 44 underwent craniofacial resection (CFR) for en bloc resection of SNMTs involving the anterior and/or lateral skull base, and 6 underwent transsphenoidal transposition of the TPGF flap. The authors categorized the TCS procedures according to the portion of the sphenoid sinus wall involved (i.e., superior, lateral, and superolateral). Superior sphenoidotomy was used in patients requiring anterior CFR. Lateral sphenoidotomy was further divided into 2 subtypes, with type 1 procedures performed for the transsphenoidal transpositioning of the TPGF, and type 2 procedures used in patients requiring lateral CFR. Superolateral sphenoidotomy was used in anterolateral CFR.CONCLUSIONSTCS still represents a useful tool in the armamentarium of neurosurgeons treating central skull base lesions. The newly proposed surgical classification facilitates a profound understanding of TCS and how to incorporate this technique into clinical practice.

scholarly journals Anatomical Step-by-Step Dissection of Complex Skull Base Approaches for Trainees: Surgical Anatomy of the Posterior Petrosal Approach

2018 ◽  
Vol 80 (04) ◽  
pp. 338-351 ◽  
Author(s):  
Christopher S. Graffeo ◽  
Maria Peris-Celda ◽  
Avital Perry ◽  
Lucas P. Carlstrom ◽  
Colin L.W. Driscoll ◽  
...  
Keyword(s):  
Skull Base ◽  
Cranial Nerves ◽  
Skin Incision ◽  
Surgical Anatomy ◽  
Muscle Flaps ◽  
Anatomical Dissection ◽  
Superior Petrosal Sinus ◽  
Key Steps ◽  
Retrolabyrinthine Approach ◽  
Burr Holes

Introduction Although numerous anatomical and operative atlases have been published, those that have focused on the skull base either have provided views that are quite difficult to achieve in the operating room to better depict surgical anatomy or are written at the level of an audience with considerable knowledge and experience. Methods Five sides of three formalin-fixed latex-injected specimens were dissected under microscopic magnification. A posterior petrosectomy approach was performed by three neurosurgical residents at different training levels with limited previous experience in anatomical dissection mentored by the senior authors (C. L. W. D. and M. J. L.) and a clinical skull base fellow with additional anatomical dissection experience (M. P. C.). Anatomical dissections were performed until the expected level of dissection quality was achieved to demonstrate each important step of the surgical approach that would be understandable to all trainees of all levels. Following dissection education, representative case applications were reviewed. Results The posterior petrosectomy (also known as presigmoid retrolabyrinthine approach) affords excellent access to cranial nerves III to XI and a diverse array of pathologies. Key steps include positioning and skin incision, scalp and muscle flaps, burr holes, craniotomy flap elevation, superficial mastoidectomy, otic capsule exposure and presigmoid dura decompression, primary presigmoid durotomy, inferior temporal durotomy, superior petrosal sinus ligation, tentorium sectioning, and final exposure. Conclusion The posterior petrosectomy is a challenging approach; thorough operative-style laboratory dissection is essential to provide trainees with a suitable guide. We describe a comprehensive approach to learning this technique, intended to be understandable and usable by a resident audience.

Anatomical Step-by-Step Dissection of Complex Skull Base Approaches for Trainees: Surgical Anatomy of the Retrosigmoid Approach

2019 ◽  
Author(s):  
Christopher S. Graffeo ◽  
Maria Peris-Celda ◽  
Avital Perry ◽  
Lucas P. Carlstrom ◽  
Colin L.W. Driscoll ◽  
...  
Keyword(s):  
Skull Base ◽  
Three Dimensional ◽  
Skin Incision ◽  
Surgical Anatomy ◽  
Retrosigmoid Approach ◽  
Muscle Flaps ◽  
Wide Clinical Application ◽  
Lateral Suboccipital Approach ◽  
Key Steps ◽  
Flap Elevation

Abstract Introduction Neurosurgical anatomy is traditionally taught via anatomic and operative atlases; however, these resources present the skull base using views that emphasize three-dimensional (3D) relationships rather than operative perspectives, and are frequently written above a typical resident's understanding. Our objective is to describe, step-by-step, a retrosigmoid approach dissection, in a way that is educationally valuable for trainees at numerous levels. Methods Six sides of three formalin-fixed latex-injected specimens were dissected under microscopic magnification. A retrosigmoid was performed by each of three neurosurgery residents, under supervision by the senior authors (C.L.W.D. and M.J.L.) and a graduated skull base fellow, neurosurgeon, and neuroanatomist (M.P.C.). Dissections were supplemented with representative case applications. Results The retrosigmoid craniotomy (aka lateral suboccipital approach) affords excellent access to cranial nerve (CN) IV to XII, with corresponding applicability to numerous posterior fossa operations. Key steps include positioning and skin incision, scalp and muscle flaps, burr hole and parasigmoid trough, craniotomy flap elevation, initial durotomy and deep cistern access, completion durotomy, and final exposure. Conclusion The retrosigmoid craniotomy is a workhorse skull base exposure, particularly for lesions located predominantly in the cerebellopontine angle. Operatively oriented neuroanatomy dissections provide trainees with a critical foundation for learning this fundamental skull base technique. We outline a comprehensive approach for neurosurgery residents to develop their familiarity with the retrosigmoid craniotomy in the cadaver laboratory in a way that simultaneously informs rapid learning in the operating room, and an understanding of its potential for wide clinical application to skull base diseases.

scholarly journals Modified Three-Dimensional Skull Base Model With Artificial Dura Mater, Cranial Nerves, and Venous Sinuses for Training in Skull Base Surgery

2008 ◽  
Vol 48 (12) ◽  
pp. 582-588 ◽  
Author(s):  
Kentaro MORI ◽  
Takuji YAMAMOTO ◽  
Kazutaka OYAMA ◽  
Hideaki UENO ◽  
Yasuaki NAKAO ◽  
...  
Keyword(s):  
Skull Base ◽  
Dura Mater ◽  
Skull Base Surgery ◽  
Cranial Nerves ◽  
Three Dimensional ◽  
Venous Sinuses

The mandibular swing-transcervical approach to the skull base: anatomical study

1993 ◽  
Vol 78 (4) ◽  
pp. 673-681 ◽  
Author(s):  
Mario Ammirati ◽  
Jianya Ma ◽  
Melvin L. Cheatham ◽  
Zhong Tao Mei ◽  
Joseph Bloch ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Skull Base ◽  
Internal Carotid ◽  
Cranial Nerves ◽  
Anatomical Study ◽  
Surgical Anatomy ◽  
Content Type ◽  
Transcervical Approach ◽  
Lower Cranial Nerves

✓ This report describes in a stepwise fashion the surgical anatomy of an approach to the midline and lateral compartments of the skull base (clivus, infralabyrinthine/infratemporal regions). The salient features of this procedure are represented by a mandibulotomy and by detachment of the pharynx from the skull base through a combined oral and cervical approach. There is full neurovascular control of the internal carotid artery and lower cranial nerves with the possibility of complete exposure of the intrapetrous and intracavernous segments of the internal carotid artery on the side of the exposure. This approach, which may be regarded as an expansion of the original work of Krespi, should be considered when dealing aggressively with extensive skull-base lesions invading the midline and lateral compartments of the skull base.

Construction of a Three-Dimensional Interactive Model of the Skull Base and Cranial Nerves

Neurosurgery ◽  
2007 ◽  
Vol 60 (5) ◽  
pp. 901-910 ◽  
Author(s):  
Yukinari Kakizawa ◽  
Kazuhiro Hongo ◽  
Albert L. Rhoton
Keyword(s):  
Skull Base ◽  
Dura Mater ◽  
Personal Computer ◽  
Focal Point ◽  
Cranial Nerves ◽  
Three Dimensional ◽  
Reference Points ◽  
Operative Planning ◽  
Time Limitations ◽  
D Model

Abstract OBJECTIVE The goal was to develop an interactive three-dimensional (3-D) computerized anatomic model of the skull base for teaching microneurosurgical anatomy and for operative planning. METHODS The 3-D model was constructed using commercially available software (Maya 6.0 Unlimited; Alias Systems Corp., Delaware, MD), a personal computer, four cranial specimens, and six dry bones. Photographs from at least two angles of the superior and lateral views were imported to the 3-D software. Many photographs were needed to produce the model in anatomically complex areas. Careful dissection was needed to expose important structures in the two views. Landmarks, including foramen, bone, and dura mater, were used as reference points. RESULTS The 3-D model of the skull base and related structures was constructed using more than 300,000 remodeled polygons. The model can be viewed from any angle. It can be rotated 360 degrees in any plane using any structure as the focal point of rotation. The model can be reduced or enlarged using the zoom function. Variable transparencies could be assigned to any structures so that the structures at any level can be seen. Anatomic labels can be attached to the structures in the 3-D model for educational purposes. CONCLUSION This computer-generated 3-D model can be observed and studied repeatedly without the time limitations and stresses imposed by surgery. This model may offer the potential to create interactive surgical exercises useful in evaluating multiple surgical routes to specific target areas in the skull base.

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