Straight sinus: ultrastructural analysis aimed at surgical tumor resection

Area of Science:

• Neurosurgery
• Anatomy
• Histology

Background:

• Accurate knowledge of the straight sinus (SS) anatomy is crucial for surgical interventions.
• Previous observations suggested potential venous blood flow maintenance within the SS despite wall manipulation, diverging from established histological descriptions.

Purpose of the Study:

• To investigate the possibility of dissecting the straight sinus (SS) walls while preserving its lumen.
• To describe the histological and ultrastructural composition of the SS wall.

Main Methods:

• Analysis of 22 cadaveric specimens, dividing the SS into anterior, middle, and posterior portions.
• Assessment of SS wall characteristics, dissectability, thickness, and tissue composition (collagen, elastic fibers) using Masson's trichrome and Verhoeff's stains.
• Comparison of SS wall variables with other venous sinuses and ultrastructural analysis via transmission electron microscopy.

Main Results:

• A vein-like structure independent of SS walls was identified in 36.36% of samples.
• The inferior SS wall was delaminable in 95.45% of samples, unlike the lateral walls.
• The inferior SS wall was significantly thicker, with less collagen and more elastic fibers, connective tissue, blood vessels, and nerve fibers, including muscle fibers.

Conclusions:

• The identified vein-like structure within the SS may represent an anatomical variation preserving venous blood flow.
• The thicker inferior SS wall's composition, including muscle fibers, explains its delaminability, while lateral wall delamination is not advised.
• Ultrastructural findings support the presence of muscle fibers in the inferior SS wall.