Mastoid Pouch of the Sigmoid Sinus- an Extraordinary Anatomical Variant

Overview

Journal Surg Radiol Anat

Specialties Anatomy & Histology
General Surgery
Radiology

Date 2025 Feb 18

PMID 39966181

Authors

Mugurel Constantin Rusu

Corneliu Toader

Razvan Costin Tudose

Affiliations

Soon will be listed here.

Abstract

Purpose: The dural sigmoid sinus (SS) is a major surgical landmark. It is aimed to report an extraordinary and clinically significant anatomical variation- the mastoid pouch of the SS, which replaces the mastoid air cells.

Method: The archived angioCT file of a 45 y.o. male was retrospectively studied on planar sections and by three-dimensional volume renderings.

Results: An expansive mastoid pouch of the left SS was found, measuring 1.74 cm in transverse diameter and 2.18 cm in sagittal diameter, replacing the typical mastoid air cell system. This SS pouch extended to the mastoid cortex and was covered by a robust (1.41 cm broad) tegmen sinus sigmoidei. The bony wall between the SS pouch and the mastoid portion of the facial canal was 4.65 mm thick.

Conclusion: The marked venous encroachments into the mastoid region emphasise the necessity for comprehensive preoperative imaging and careful selection of surgical approaches to prevent inadvertent vascular compromise.

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