Increased systemic venous pressure leading to intracranial hypertension in a patient with a ventriculoatrial shunt: illustrative case.

backgroundVentriculoatrial (VA) shunt placement is an alternative treatment for hydrocephalus when ventriculoperitoneal shunt placement is not feasible. While shunt obstruction and infection are well-known complications, elevated systemic venous pressure is likely an underrecognized cause of dysfunction. Elevated right atrial pressure can reduce the pressure gradient for CSF drainage, leading to intracranial hypertension despite a mechanically functional shunt. OBSERVATIONS: A 19-year-old female with a VA shunt developed refractory intracranial hypertension despite multiple valve adjustments and a mechanically functional shunt. Venography with pressure measurement revealed elevated systemic venous pressure, with jugular venous pressures elevated to 12-13 mm Hg. Shunt revision confirmed high outflow resistance at the atrial end (20 cm H2O = approximately 15 mm Hg), suggesting impaired CSF drainage due to elevated right atrial pressure. Nitroglycerin reduced intracranial pressure but was discontinued due to headache exacerbation. Subsequently, acetazolamide provided symptomatic relief. LESSONS: Elevated systemic venous pressure can impair VA shunt function and cause intracranial hypertension. Preoperative central venous pressure measurement may help identify patients at risk. Nitroglycerin may serve as a diagnostic tool for VA shunt dysfunction related to elevated venous pressure. Awareness of increased systemic venous pressure as a factor in VA shunt dysfunction is warranted. https://thejns.org/doi/10.3171/CASE25226.