Objectives: A serious, catastrophic complications of endoscopic third ventriculostomy (ETV) is basilar artery (BA) damage. Although the BA has been discussed as the cause of hemorrhage and even pseudoaneurysm, variations of the posterior cerebral artery proximal segment (P1) and its protrusion into the third ventricle floor have not been emphasized. The authors report a series of cases in which the P1 segment was located at the stoma during an ETV and was at risk for perforation. Precautionary techniques for complication avoidance are described.
Methods: A retrospective review was performed of all ETVs performed in adults at our institution between 2004 and 2008. Cases were identified in which the P1 segment was noted to herniate into the stoma at the time of third ventricular floor fenestration.
Results: Among 65 cases reviewed, 6 were identified in which the P1 segment significantly herniated into an area of the stoma at the time of third ventricular floor fenestration. In no case was the P1 segment injured by the ETV procedure. Each of the 6 patients had opaque third ventricle floors. A “cookie-cut” technique was used in which the opaque third ventricle floor was abraded to reveal the underlying translucent membrane, offering an improved view of arteries in the basilar cisterns. In 4 of 6 patients, ETV resulted in clinical improvement.
Conclusions: The posterior cerebral artery P1 segment is potentially at risk during ETV in adults as well as children. Awareness and proper precautions may help reduce injuries to either the P1 or the basilar apex during an ETV.