Pseudoaneurysms on the peripheral part of the anterior cerebral artery (ACA) are sometimes caused by head injury. We have encountered a case of pseudoaneurysm of the ACA caused by ventricular tapping during a shunt operation.
A 67-year-old woman had aneurysmal clipping surgery at the onset of subarachnoid hemorrhage due to ruptured left middle cerebral artery aneurysm. She developed normal pressure hydrocephalus and ventriculoperitoneal shunt surgery was performed. During the operation, we tried to tap the anterior horn of the right lateral ventricle, but, the ventricular needle did not run smoothly. Removing the inner cylinder, active arterial bleeding was observed. Postoperative CT images showed intraventricular hematoma and intracerebral hematoma in the right frontal lobe. Immediately, external ventricular drainage was performed via the left anterior horn of the lateral ventricle. An angiogram showed an aneurysm at the non-bifurcation portion of the distal right ACA. Radical treatment of the aneurysm was performed. A clot was observed on the right side of the bifurcation of the peripheral ACA. After removing the clot, it was clear that all layers of the vessel wall were perforated suggesting a pseudoaneurysm. Suturing and wrapping was performed at the orifice. The intraoperative angiogram did not show the distal part of the ACA from the pseudoaneurysm. Postoperative CT images did not show a cerebral infarction. The patient underwent ventriculoperitoneal shunt surgery 1 month later. She was discharged without any neurological deficits.
It is important to avoid injury of the ACA when tapping the lateral ventricle. If injury of the cerebral artery is suspected because of bleeding, the cerebral artery should be immediately investigated and the injury should be treated to prevent further bleeding. Neck clipping for pseudoaneurysm is often difficult and surgeons should also be prepared for vascular anastomosis.
