Iatrogenic pseudoaneurysms associated with cerebrospinal fluid diversion procedures

BACKGROUND: Cerebrospinal fluid diversion procedures, including ventriculoperitoneal (VP) shunt and external ventricular drain insertion, are common treatments for hydrocephalus. Common complications include obstruction, infection, and hemorrhage. Pseudoaneurysm formation secondary to catheter insertion is a distinctly rare complication, and usually involves the anterior cerebral artery or branches of the external carotid artery (superficial temporal artery or middle meningeal artery). CASE DESCRIPTION: We present the case of a fusiform pseudoaneurysm in a 36-year-old female, which arose from a branch of the middle cerebral artery following VP shunt insertion. Parenchymal and intraventricular hemorrhage at the catheter insertion site developed 15 days postoperatively. The VP shunt was removed, and the aneurysmal segment was coagulated and occluded. Use of a limited dural opening during ventricular catheter placement may have been a factor in pseudoaneurysm formation. CONCLUSIONS: The literature regarding this rare complication is reviewed. Careful consideration should be given to vascular anatomy when planning shunt insertions, and a cruciate dural opening for cortical visualization and coagulation may help avoid this complication. Prompt identification and management of iatrogenic pseudoaneurysms is essential to avoid re-bleeding and associated hemorrhagic complications.