Introduction A 45-year-old female presented to the emergency department with a headache and reduced level of consciousness. CT scan revealed widespread acute subarachnoid haemorrhage with hydrocephalus, confirmed by CTA as a giant basilar artery aneurysm.

Aim of the Study Highlight complications of giant aneurysm treatment.

Methods The patient was transferred to a neuroscience centre for endovascular treatment. An EVD was inserted. A flow-diverting stent (Silk Vista Baby) and 9-XL coils were deployed. Post-deployment angiography showed satisfactory positioning. On day 1 post-procedure, the patient developed right arm weakness/aphasia. CT showed coil-streak artifact, however MRI/MRA indicated a small area of restricted diffusion and high T2 signal, indicating an acute infarct. Coil compaction and proximal stent displacement into the aneurysm sac were also observed.

Results A rescue/re-treatment was performed. A trans-circulation approach via the PCOM was attempted due to unsuccessful antegrade catheterisation through the vertebral artery. The stent was dislodged into the aneurysm sac, enabling re-treatment of the aneurysm neck with a new device. A Pipeline flow diverter was deployed, and additional coils were placed within the compacted coil mass. Dual antiplatelet therapy was initiated. The patient demonstrated near-complete recovery, with aneurysm occlusion and improved mass effect on follow-up MRI/MRA at 6 months.

Conclusion In conclusion, careful planning is necessary for endovascular treatment of giant aneurysms. Consideration of larger inflow volumes and longer stent landing-zones can prevent complications. In cases of complications, trans-circulation rescue therapy may facilitate stent re-catheterisation allowing for repositioning, or stent displacement allowing for deployment of a new device.

Disclosure of Interest No conflicts of interest.

Dr S Kular – Nothing to disclose.

Dr R Dyde – Nothing to disclose.

Dr G Tse – Nothing to disclose.