Vertebral artery pseudoaneurysm complicating posterior C1-2 transarticular screw fixation: case report

BACKGROUND: Vertebral artery injury during posterior C1-2 transarticular screw fixation occurs in approximately 3% of patients and may remain asymptomatic or result in arteriovenous fistulae, occlusion, narrowing, or dissection of the vertebral artery, and lead to transient ischemic attacks, stroke, or death. CASE DESCRIPTION: This is the first report of a pseudoaneurysm resulting from damage to the vertebral artery during the procedure. This 31-year-old male underwent posterior C1-2 transarticular screw fixation for unstable os odontoideum. Injury to the left vertebral artery occurred while the hole for the left screw was being drilled. Temporary control of bleeding with local pressure was followed by immediate postoperative angiography that revealed a left vertebral artery pseudoaneurysm. Although the patient remained asymptomatic, therapeutic anticoagulation was instituted 6 hours postoperatively. Increasing size of the pseudoaneurysm was noted on routine follow-up angiography 4 weeks later. Endovascular occlusion of the pseudoaneurysm and left vertebral artery, with preservation of vertebrobasilar flow through the right vertebral artery, was accomplished without neurological consequence. CONCLUSIONS: Vertebral artery pseudoaneurysm complicating posterior C1-2 transarticular screw fixation may be effectively treated with endovascular approaches.