The cochlear aqueduct: An important landmark in lateral skull base surgery

1998 ◽  
Vol 118 (4) ◽  
pp. 532-536
Author(s):  
Asim Aslan ◽  
Maurizio Falcioni ◽  
Fatih Ridvan Balyan ◽  
Giuseppe De Donato ◽  
Abdelkader Taibah ◽  
...  
Keyword(s):  
Skull Base ◽  
Sagittal Plane ◽  
Skull Base Surgery ◽  
Cranial Nerves ◽  
Close Relation ◽  
Cochlear Aqueduct ◽  
Lateral Skull Base ◽  
Important Landmark ◽  
Temporal Bones ◽  
Relationship Of

The cochlear aqueduct (CA) is used as a landmark in lateral skull base surgery. In this study anatomic relationships between the CA and adjacent neurovascular structures were examined by dissecting 32 temporal bones. Observations of the relationship of the external opening (EO) of the CA with the ninth, tenth, and eleventh cranial nerves, inferior petrosal sinus (IPS), and intrapetrous carotid artery (ICA) were noted. In addition to the distance of the EO of the CA to the vertical portion of the ICA, the entire length of the CA and the width of the EO were also measured. The ninth nerve was the only structure lodged at the EO of the CA in 34.4% of bones. However, in 40.6% of bones only the IPS crossed the EO of the CA, although the ninth nerve was situated just anteroinferiorly in the vicinity of the EO. In 15.6% of bones it was possible to observe both the ninth nerve and the IPS crossing the EO. In 9.4% of bones the EO of the CA was found to be occupied by the tenth and eleventh nerves. It was also observed that the ICA was located anteriorly on the same sagittal plane with the EO in 15.6% of bones. It was concluded that although in 90% of cases the EO of the CA was in close relation with the ninth nerve, other structures such as the IPS, the tenth and eleventh cranial nerves, and the ICA were also at risk during drilling in this area because of their intimate relationships with the EO of the CA.

Anatomical considerations of high jugular bulb in lateral skull base surgery

1997 ◽  
Vol 111 (4) ◽  
pp. 333-336 ◽  
Author(s):  
Asim Aslan ◽  
Maurizio Falcioni ◽  
Alessandra Russo ◽  
Giuseppe De Donato ◽  
Fatih Ridvan Balyan ◽  
...  
Keyword(s):  
Skull Base ◽  
Skull Base Surgery ◽  
Cranial Nerves ◽  
Internal Auditory Canal ◽  
Jugular Bulb ◽  
Mastoid Process ◽  
High Jugular Bulb ◽  
Lateral Skull Base ◽  
Significant Difference ◽  
Temporal Bones

AbstractIn order to study high jugular bulb management in lateral skull base surgery, an anatomical study was conducted on 30 temporal bones by examining the relationship between the internal auditory canal (IAC) and the jugular bulb. The following parameters were measured: 1) Height of the jugular bulb (H) … distance between the level of the jugular bulb dome and the line passing through the confluence of the sigmoid sinus with the jugular bulb (SS-JB), 2) Mastoid length (ML) … distance between the mastoid process and middle cranial fossa dura, 3) Distance between the most inferior part of the porus acousticus and jugular bulb dome (A), 4) Distance between the porus acousticus and SS-JB (B). The jugular bulb was defined as high when it occupied more than two thirds of (B). The incidence of a high jugular bulb was 23 per cent in this study. When the jugular bulb was high, the mean (H) and (A) were 9.4 ± 1.9 mm and 2.7 ± 0.5 mm, respectively. (H) was higher on the right side than on the left side. No statistically significant difference was found between small and large mastoids (t-test: p>0.05). It was concluded that when a high jugular bulb was encountered during lateral skull base surgery, the jugular bulb position allows a very small working area inferior to the IAC. In these cases, a 3 or 4 mm depression of the jugular bulb is necessary in order to expose the lower cranial nerves. This can be accomplished by lowering the jugular bulb with the technique already described.

The cochlear aqueduct: An important landmark in lateral skull base surgery☆☆☆★★★♢

1998 ◽  
Vol 118 (4) ◽  
pp. 532-536 ◽  
Author(s):  
ASIM ASLAN ◽  
MAURIZIO FALCIONI ◽  
FATIH RIDVAN BALYAN ◽  
GIUSEPPE DE DONATO ◽  
ABDELKADER TAIBAH ◽  
...  
Keyword(s):  
Skull Base ◽  
Skull Base Surgery ◽  
Cochlear Aqueduct ◽  
Lateral Skull Base ◽  
Important Landmark

scholarly journals Osteological studies of skull base neurovascular area in reference to infratemporal approach to skull basec

2021 ◽  
Vol 4 (3) ◽  
pp. 89-93
Author(s):  
Harsh Sharma
Keyword(s):  
Skull Base ◽  
Cranial Nerves ◽  
Relative Size ◽  
Jugular Foramen ◽  
Surgical Approaches ◽  
Carotid Canal ◽  
Stylomastoid Foramen ◽  
Lateral Skull Base ◽  
Infratemporal Approach ◽  
Relationship Of

Surgical approaches to the lateral skull base often lead to tearing of vessels and piecemeal removal of the tumour. This study is aimed to delineate exact relationship of the various foramina at the lateral skull base. The coronal dimensions of the jugular foramina are larger as compared to sagittal with right sided dominance also noticed in the case of carotid canal. The width of “Keel” separating the carotid and jugular foramina normally varies from 0.4 to1.4 centimetres and may not always suggest the erosion of the foramen of skull base scans, unless the erosion is associated with irregularity or demineralization the thickness of this keel really depends upon relative size of the vessels and location of foramina. Area between stylomastoid foramen, carotid canal and jugular foramen is roughly wedge shaped. The angle subtended by carotid and jugular at the stylomastoid foramen is about 36.84whereas the location of stylomastoid foramen and internal carotid axis pose an angle of 83:16. The angle subtended by stylomastoid and jugular at carotid on an average 59:31. The space between these structures is measured to be 0.642centimetres which can be verified on tomograms. By using these measurements, the precise location of the upper end of the vessels could be predicted, whereas the superior stump could be clamped with minimal exposure of the skull base and identification and location of the last four cranial nerves is found out. This could avoid injuries and subsequent morbidity while carrying out surgery in this region.

Transcanal Computed Tomography Views for Transcanal Endoscopic Lateral Skull Base Surgery: Pilot Cadaveric Study

2019 ◽  
Author(s):  
Rory J. Lubner ◽  
Samuel R. Barber ◽  
Renata M. Knoll ◽  
Judith Kempfle ◽  
Daniel J. Lee ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Skull Base ◽  
Skull Base Surgery ◽  
Imaging Study ◽  
Preoperative Imaging ◽  
Slice Thickness ◽  
Imaging Evaluation ◽  
Mean Values ◽  
Lateral Skull Base ◽  
Temporal Bones

Abstract Objectives Transcanal endoscopic operative approaches provide for a minimally invasive surgical portal to the lateral skull base. Traditional preoperative imaging evaluation involves computed tomography (CT) acquisition in the axial and coronal planes that are not optimized for the transcanal surgical corridor. Herein, we describe a novel CT-based “transcanal view” for preoperative surgical planning and intraoperative navigation. Study Design Present study is a cadaveric imaging study. Methods Cadaveric temporal bones (n = 6) from three specimens underwent high-resolution CT (0.625 mm slice thickness). Using three-dimensional (3D) Slicer 4.8, reformatted “transcanal” views in the plane of the external auditory canal (EAC) were created. Axial and coronal reformats were used to compare and measure distances between anatomic structures in the plane of the EAC. Results The degree of oblique tilt for transcanal CT reformats was 6.67 ± 1.78 degrees to align the EAC in axial and coronal planes. Anticipated critical landmarks were identified easily using the transcanal view. Mean values were 8.68 ± 0.38 mm for annulus diameter, 9.5 ± 0.93 mm for isthmus diameter, 10.27 ± 0.73 mm for distance between annulus and isthmus, 2.95 ± 0.13 mm for distance between annulus and stapes capitulum, 5.12 ± 0.35 mm for distance between annulus and mastoid facial nerve, and 19.54 ± 1.22 mm for EAC length. Conclusions This study is the first to illustrate a novel “transcanal” CT sequence intended for endoscopic lateral skull base surgery. Future studies may address how incorporation of a transcanal CT reformat may influence surgical decision making.

Increasing Safety in Lateral Skull Base Surgery by Navigation

Skull Base ◽  
2007 ◽  
Vol 17 (S 1) ◽  
Author(s):  
Rainer Schmelzeisen ◽  
Marc Metzger
Keyword(s):  
Skull Base ◽  
Skull Base Surgery ◽  
Lateral Skull Base

Full tractography for detecting the position of cranial nerves in preoperative planning for skull base surgery: technical note

2020 ◽  
Vol 132 (5) ◽  
pp. 1642-1652 ◽  
Author(s):  
Timothee Jacquesson ◽  
Fang-Chang Yeh ◽  
Sandip Panesar ◽  
Jessica Barrios ◽  
Arnaud Attyé ◽  
...  
Keyword(s):  
Skull Base ◽  
Preoperative Planning ◽  
Skull Base Surgery ◽  
Cranial Nerves ◽  
Patient Specific ◽  
Small Scale ◽  
Skull Base Tumor ◽  
Skull Base Tumors ◽  
Brain White Matter ◽  
Human Connectome Project

OBJECTIVEDiffusion imaging tractography has allowed the in vivo description of brain white matter. One of its applications is preoperative planning for brain tumor resection. Due to a limited spatial and angular resolution, it is difficult for fiber tracking to delineate fiber crossing areas and small-scale structures, in particular brainstem tracts and cranial nerves. New methods are being developed but these involve extensive multistep tractography pipelines including the patient-specific design of multiple regions of interest (ROIs). The authors propose a new practical full tractography method that could be implemented in routine presurgical planning for skull base surgery.METHODSA Philips MRI machine provided diffusion-weighted and anatomical sequences for 2 healthy volunteers and 2 skull base tumor patients. Tractography of the full brainstem, the cerebellum, and cranial nerves was performed using the software DSI Studio, generalized-q-sampling reconstruction, orientation distribution function (ODF) of fibers, and a quantitative anisotropy–based generalized deterministic algorithm. No ROI or extensive manual filtering of spurious fibers was used. Tractography rendering was displayed in a tridimensional space with directional color code. This approach was also tested on diffusion data from the Human Connectome Project (HCP) database.RESULTSThe brainstem, the cerebellum, and the cisternal segments of most cranial nerves were depicted in all participants. In cases of skull base tumors, the tridimensional rendering permitted the visualization of the whole anatomical environment and cranial nerve displacement, thus helping the surgical strategy.CONCLUSIONSAs opposed to classical ROI-based methods, this novel full tractography approach could enable routine enhanced surgical planning or brain imaging for skull base tumors.

Lateral skull base surgery: a complicated pursuit?

2007 ◽  
Vol 122 (3) ◽  
pp. 221-229
Author(s):  
V C Cousins
Keyword(s):  
Skull Base ◽  
Skull Base Surgery ◽  
Treatment Modalities ◽  
Published Data ◽  
Know How ◽  
Team Assessment ◽  
Pathological Conditions ◽  
Lateral Skull Base ◽  
Wide Range ◽  
Multi Disciplinary Team

AbstractThe management of lesions of the lateral skull base is a highly sophisticated branch of surgery generally performed by otolaryngology–head and neck surgeons as part of a multi-disciplinary team. Assessment of patients with diseases affecting the lateral skull base can be complex, as can the application of the various treatment modalities and the management of the expected and unexpected side effects of that treatment.A wide range of pathological conditions occur in the lateral skull base. Many operations and procedures have been described for dealing with them. There is not necessarily one correct solution to the management of any particular problem in the skull base, with multiple factors to be considered in planning and intervention.As surgeons, we need to know how our own results and outcomes compare with pooled, published data concerning the implications and complications occurring as a result of intervention, in order to better advise our patients on their management.

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