Importance of repeat angiography in the diagnosis of iatrogenic anterior cerebral artery territory pseudoaneurysm following endoscopic sinus surgery.

Iatrogenic intracranial pseudoaneurysm formation and rupture are rare complications following endoscopic sinus surgery. Given the propensity for devastating neurologic injury after a relatively routine procedure, swift diagnosis and treatment is essential. The authors present a patient who experienced bifrontal intracranial hemorrhage and subarachnoid hemorrhage due to a ruptured iatrogenic frontopolar artery pseudoaneurysm caused during routine endoscopic sinus surgery. The pseudoaneurysm was not present on initial angiograms but became apparent radiographically 19 days after the endoscopic procedure. Endovascular treatment consisted of coil and Onyx embolization for sacrifice of the parent vessel proximal to the lesion. Early recognition of iatrogenic intracranial vascular injury is important to allow for rapid treatment. Initial radiographic studies may be unreliable in excluding the presence of a pseudoaneurysm so delayed repeat angiographic assessment is necessary, particularly in the presence of a high index of clinical suspicion. Endovascular techniques may provide an effective and safe option for the treatment of iatrogenic anterior cerebral artery distribution pseudoaneurysms.