It’s not always the shunt: Microthombi formation in venous collaterals causing symptoms of shunt failure in the setting of shunted hydrocephalus

We present a patient with a history of shunted hydrocephalus due to neonatal iatrogenic thoracic venous occlusion with subsequent interval development of spontaneous thoracic venous collateral occlusion as a young adult presenting with symptoms of ventriculoperitoneal shunt failure. Though the patient’s presenting symptoms were suggestive of shunt failure in the setting of known shunt dependent hydrocephalus, specific ophthalmologic findings, including venous engorgement, retinal and subconjunctival hemorrhages as well as periorbital edema in conjunction with papilledema, led to the correct diagnosis of cranio-orbital congestion secondary to microthrombi formation in the venous collateral anomalies of her chest wall. This pathology was successfully managed with warfarin. •Venous anomalies are a predisposition to impaired cerebrospinal fluid absorption.•Microthombi formation in the venous system may impair cerebrospinal fluid flow.•Venous congestion causing hydrocephalus may be managed with anticoagulation.