Occurrence of CSF-Venous Fistulas by Spinal Level and Laterality

Area of Science:

• Neurology
• Radiology
• Neurosurgery

Background:

• Cerebrospinal fluid-venous fistulas (CVFs) are a significant, often overlooked cause of spontaneous intracranial hypotension.
• These fistulas represent direct connections between the cerebrospinal fluid (CSF) space and paraspinal veins, leading to CSF loss.

Purpose of the Study:

• To systematically review and meta-analyze the prevalence of affected laterality and spinal levels of CSF-venous fistulas.
• To evaluate the distribution of CSF-venous fistulas across different spinal regions and sides.

Main Methods:

• A comprehensive literature review identified 43 relevant studies.
• Data on demographic characteristics, laterality, and spinal levels of CVFs were extracted and analyzed.
• Pooled prevalence rates were calculated, and meta-regression was used to assess laterality at specific spinal levels.

Main Results:

• CSF-venous fistulas were predominantly found on the right side (67%) compared to the left or bilateral.
• The vast majority (96%) of CVFs were located in the thoracic spine.
• Specific high-prevalence levels included T7 and T9 (19% each), followed by T10 (17%), with significantly lower prevalence in the lumbar and cervical spine.

Conclusions:

• Localization of CSF-venous fistulas is critical for effective therapeutic planning and intervention.
• The study confirms a significant predominance of right-sided CVFs.
• The lower thoracic spine, specifically T7, T9, and T10, represents the most common location for these fistulas, potentially influenced by the azygous vein and arachnoid granulations.