Fatal arterial rupture during angioplasty of a flow diverter in a recurrent, previously Y-stented giant MCA bifurcation aneurysm

Background and purpose A patient with a previously Y-stented giant left middle cerebral artery (MCA) bifurcation aneurysm returned with a recurrence. Materials and methods A flow diverter (FD) was deployed through one limb of the high-porosity Y-stenting construction. The proximal FD failed to expand and an attempt at balloon angioplasty led to fatal rupture of the MCA. Results Autopsy demonstrated subarachnoid hemorrhage, vessel rupture and fracture of the proximal high-porosity stent. Microscopic photographs showed that the FD had failed to open because the guiding wire had inadvertently exited and re-entered the proximal segment of the high-porosity stent partially incorporated to the wall of the MCA. Balloon dilatation of the FD which had remained collapsed between the stent and the vessel wall caused fracture of the stent and rupture of the artery. Conclusion Angioplasty and flow-diversion of previously Y-stented aneurysms can lead to serious complications.