Sacral CSF-venous fistula: a rare entity. Illustrative case

Area of Science:

• Neurosurgery
• Interventional Radiology
• Neuroradiology

Background:

• Cerebrospinal fluid-venous fistulas (CVFs) are increasingly recognized causes of cerebrospinal fluid (CSF) leakage.
• Spontaneous intracranial hypotension (SIH) can result from CSF leakage.
• CVFs are typically found in the thoracolumbar spine, with sacral CVFs being rare.

Purpose of the Study:

• To report a case of a sacral CVF causing SIH.
• To highlight the diagnostic challenges and imaging techniques for sacral CVFs.
• To demonstrate the successful treatment of a sacral CVF via transvenous embolization.

Main Methods:

• A patient with SIH underwent diagnostic imaging, including CT and MRI.
• Lateral decubitus CT myelography (CTM) and digital subtraction myelography (DSM) were utilized to identify a sacral CVF.
• Transvenous embolization using Onyx-18 was performed for fistula obliteration.

Main Results:

• SIH symptoms were attributed to a sacral CVF at the L5-S1 level.
• Advanced imaging techniques (CTM and DSM) successfully localized the rare sacral fistula.
• Transvenous embolization resulted in complete obliteration of the CVF.

Conclusions:

• This case represents the third reported instance of a sacral CVF.
• Advanced imaging is crucial for diagnosing CVFs when routine studies are inconclusive.
• Technical considerations for CTM and DSM of the sacral region are important for accurate diagnosis.