The Anatomy of the Sigmoid-Transverse Junction According to the Tentorial Angle

Vatansever, Alper; Mut, Melike; Ergun, Kadriye Mine; Oğuz, Kader K.; Gümeler, Ekim; Bulut, Elif; Tatar, İlkan

doi:10.1097/scs.0000000000005793

Cited by 3 publications

(3 citation statements)

References 34 publications

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“…[8][9][10][11] A recent study found a relationship between the anatomy of the tentorial sinuses at the transverse-sigmoid junction and cranial morphometrics. 12 However, several studies of veins within the tentorium have demonstrated a wide variation inconsistent with direct drainage of the bridging veins into the tentorial sinuses. [13][14][15][16] Intimate knowledge of the normal variations of the tentorial venous anatomy is of critical importance for neuroradiologists guiding neurosurgeons in presurgical planning and understanding postoperative complications.…”

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confidence: 99%

Tentorial Venous Anatomy: Variation in the Healthy Population

Rosenblum

Tunacao

Chandrashekhar³

et al. 2020

AJNR Am J Neuroradiol

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BACKGROUND AND PURPOSE: A new transtentorial venous system consisting of medial, intermediate, and lateral tentorial veins, connecting infra-and supratentorial compartments, was recently shown in 2 cadaver dissections and 2 patient scans. We sought to characterize the venous patterns within the tentorium and their relation to measures of skull development in a cohort of healthy adults. MATERIALS AND METHODS: We retrospectively reviewed tentorial venous anatomy of the head using CTA/CTV performed for routine care or research purposes in 238 patients. Included studies had adequate contrast opacification of venous structures and a section thickness of #2 mm; we excluded cases with space-occupying lesions and vascular pathologies. Tentorial angle, dural sinus configurations, and measures of skull base development were assessed as predictors of tentorial venous anatomy variation via Cramér V association, the binary encoded Pearson correlation, and nearest-point algorithm with the Euclidean distance metric for clustering. RESULTS: Tentorial vein development was related to the ringed configuration of the tentorial sinuses (P , .005). There were 3 configurations. Groups 1A and 1B (n ¼ 50/238) had ringed configuration, while group 2 did not (n ¼ 188/238). Group 1A (n ¼ 38/50) had a medialized ringed configuration, and group 1B had a lateralized ringed configuration (n ¼ 12/50). Measurements of skull base development were predictive of these groups. The ringed configuration of group 1 was related to the presence of a split confluens, which correlated with a decreased internal auditory canal-petroclival fissure angle. Configuration 1A was related to the degree of petrous apex pneumatization (P value ¼ .010). CONCLUSIONS: Variations in the transtentorial venous system directly correlate with cranial development. ABBREVIATIONS: CC-JB ¼ carotid canal-jugular bulb; IAC-PCF ¼ internal auditory canal-petroclival fissure; ITV ¼ intermediate tentorial vein; LTS ¼ lateral tentorial sinus; LTV ¼ lateral tentorial vein; MTS ¼ medial tentorial sinus; MTV ¼ medial tentorial vein; RC ¼ ringed configuration

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mentioning

confidence: 99%

Tentorial Venous Anatomy: Variation in the Healthy Population

Rosenblum

Tunacao

Chandrashekhar³

et al. 2020

AJNR Am J Neuroradiol

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“…It is known, in fact, that veins of the brain have no muscular tissue in their very thin wall, meaning that the risk of rupture is very high. 25 In the literature, cases with thrombosis or/obstruction of the SS caused by MCC which required packing, are reported. 2,6 In our opinion, it is important to remember that some contraindications exist for resection/packing of the sinus: absence or significant asymmetry of the contralateral transverse and sigmoid sinuses, with the affected side being the dominant flow system; limited thrombosis of the sinus that does not require aggressive management; presence of an intracranial complication that raises intracranial pressure (meningitis, brain abscess, subdural abscess).…”

Section: Surgical Key Pointmentioning

confidence: 99%

Isolated Congenital Mastoid Cholesteatoma with no Involvement of Aditus Ad Antrum and Middle Ear

Pace

Iannella

Rossetti

et al. 2021

Clin Med Insights Case Rep

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Cholesteatoma is a non-neoplastic, keratinized squamous epithelial lesion that affects the temporal bone. The middle ear is the most frequent, while the isolated cholesteatoma of the mastoid is rare. The aim of this study was to describe a rare case of isolated mastoid cholesteatoma with no involvement of aditus ad antrum and middle ear including a literature review of the topic. This case report describes the case of a 58 years old female with a cholesteatoma isolated in the mastoid region, evidenced by imaging (computer tomography and magnetic resonance). A mastoidectomy was performed: mastoid process was completely involved, but antrum was not reached. Moreover, it reached the soft tissue of stylomastoid foramen as well as the posterior belly of the digastric muscle. In the literature few articles described cases of cholesteatoma isolated in the mastoid region. Research was conducted using PubMed and reference list and there were considered only reports about cholesteatoma exclusively located in the mastoid process without involvement of antrum or middle ear. Fourteen articles were included in this review, with a total number of 23 cases of cholesteatoma isolated in the mastoid region. All papers analyzed reported the cases of isolated mastoid cholesteatoma that presented a congenital origin. Its diagnosis is difficult, therefore, imaging evaluation is mandatory and surgery is the treatment of choice. Mastoid cholesteatomas without involvement of aditus ad antrum and middle ear are rare and only 23 cases are reported in literature. Our case is in line with all clinical and diagnostic features of this rare disease, but it is the only one that evidenced an exposure of the soft tissue of stylomastoid foramen as well as the posterior belly of the digastric muscle. The treatment of choice was the surgical one, avoiding damaging of important anatomo-functional structure.

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“…Correct placement requires the surgeon to correctly identify the location of the cranial surface projection of the transversesigmoid junction. Most identifcation methods use the asterion as the reference point for this location [1][2][3][4][5][6]. However, Bozbuga et al [7] and da Silva et al [8] present key studies (anatomical, radiological, and clinical) reporting that the asterion is not a reliable landmark for burr hole placement in the retrosigmoid approach.…”

Section: Introductionmentioning

confidence: 99%

Computed Tomography Study of the Retrosigmoid Craniotomy Keyhole Approach Using Surface Landmarks

Zhou

Liu

et al. 2023

International Journal of Clinical Practice

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Background. Due to a lack of accessibility and individual differences in surgical procedures, many previous studies on keyholes are not practical. Objective. To study the surface landmarks for optimal keyhole placement in the retrosigmoid approach. Methods. The three-dimensional (3D) skull images of 79 patients were reconstructed using workstations, with a total of 149 hemiskull base 3D images then analyzed. Skull-surface landmarks were marked, the lateral-skull surface was observed, and the positional relationships between the asterion and the extension line of the posterior margin of the mastoid process were measured. The position of the superior curvature of the sigmoid sinus groove was located before it was projected onto the lateral surface of the skull and defined as the keypoint. The positional relationship between the keypoint and the skull-surface landmarks was observed in an established coordinate system using spatial proportion relationships. Results. The asterion was located around the extension line of the posterior margin of the mastoid process, and the vertical distance from the extension line was <15 mm. It was found that 93.29% (139/149) of the keypoints were located in a 7 mm radius circle, with the center at (−0.41, −3.01) in the coordinate system in the 3D computed tomography images. Conclusion. When using this method, the spatial proportion relationship of the anatomical marks can accurately locate keyholes, therefore providing technical support when employing the retrosigmoid approach.

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The Anatomy of the Sigmoid-Transverse Junction According to the Tentorial Angle

Cited by 3 publications

References 34 publications

Tentorial Venous Anatomy: Variation in the Healthy Population

Tentorial Venous Anatomy: Variation in the Healthy Population

Isolated Congenital Mastoid Cholesteatoma with no Involvement of Aditus Ad Antrum and Middle Ear

Computed Tomography Study of the Retrosigmoid Craniotomy Keyhole Approach Using Surface Landmarks

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