Evaluation of CSF shunt function: value of functional examination with contrast material

Area of Science:

• Neurosurgery
• Radiology
• Medical Imaging

Background:

• Hydrocephalus management often involves cerebrospinal fluid (CSF) shunts.
• Assessing shunt function can be challenging, requiring methods to evaluate both physical patency and drainage efficacy.

Purpose of the Study:

• To demonstrate the efficacy and utility of functional positive-contrast shuntography.
• To differentiate between anatomic and physiologic shunt failure.
• To precisely localize shunt obstructions.

Main Methods:

• Functional shuntography combines fluoroscopic assessment of shunt patency with serial CT scans to evaluate contrast material dissipation.
• Anatomic shuntogram checks shunt and valve patency post-contrast injection.
• Physiologic shuntogram assesses ventricular fluid drainage adequacy by tracking iodine dissipation rate.

Main Results:

• 82 functional shuntograms were performed in 55 patients, with 51 abnormalities detected.
• 22 cases showed shunt patency but slow contrast dissipation, with 18 adults improving after drainage pressure reduction.
• Shunt obstruction was clearly localized in all 29 cases of frank obstruction.

Conclusions:

• Functional shuntography is a valuable tool for evaluating shunted hydrocephalic patients, particularly adults with inadequate responses.
• The technique accurately distinguishes between normal function, anatomic failure, and physiologic failure.
• It enables precise localization of obstructions and demonstrates physiologic failure even with patent shunts.