Thromboembolic complication induced stable occlusion of a ruptured basilar tip aneurysm. Case report and review of the literature

Abstract

We describe a case of a ruptured basilar bifurcation aneurysm that thrombosed during preparation for endovascular therapy as a complication of diagnostic angiogaphy, and showed a favorable evolution during long-term follow-up. Endogenous thrombosis of ruptured, non giant aneurysms is uncommon. The persistence of occlusion over time in such cases is not well established. Two weeks after rupture, a 6 x 8 mm basilar bifurcation aneurysm was referred for endovascular treatment. During preparation for endovascular coil occlusion, without having any endovascular material at the level of the basilar artery, a complete thrombotic occlusion of the basilar bifurcation and aneurysm was observed. Given the good collateral circulation for both posterior cerebral arteries no thrombolysis was undertaken. The early follow-up of seven days, three and six months showed a complete recanalization of the basilar artery and remodeling of the basilar bifurcation. The 20 months imaging follow-up demonstrated a small aneurysm regrowth at the prevoius location that remained stable during the follow-up of seven years. Unchanged biological and hemodynamic characteristics. however, may pose an elevated risk of a new aneurysm formation over time, making long-term imaging follow-up, and in case of progression, aneurysm occlusion necessary for the patient.

Figure 1

A) Acute plain CT scan demonstrating diffuse subarachnoid hemorrhage and mild ventricular enlargement. B) Left vertebral DS-angiography, PA view, showing a saccular aneurysm at the basilar bifurcation. C) Left vertebral angiogram, lateral view: the tip of the basilar artery is occluded (arrow), the posterior cerebral arteries and the aneurysm are not filling. D) Right and left internal carotid angiograms demonstrate good flow within both posterior cerebral arteries through the posterior communicating arteries (arrow).

Figure 2

Left vertebral artery DSA and 3D reconstructed angiograms one week (A) and 3 months (B,C) after treatment attempt. Whilst the 1 week follow-up shows recanalization of the distal basilar artery without aneurysm filling, the 3 months follow-up images show a complete remodeling of the basilar bifurcation.

Figure 3

TOF MRA performed 20 months (A) and 7 years (B) after the event, demonstrating a small, approximately 2 x 3 mm aneurysm regrowth at the level of the former neck, which proved to be stable during the follow-up.