Introduction The rate of intracranial aneurysm recurrence/residuum following surgical clipping varies. The risk of subarachnoid haemorrhage following surgical clipping is up to 2%¹.

Aim of Study The study aimed to describe the outcomes of the use of flow diversion in the treatment of residual intracranial aneurysms following surgical clipping.

Methods Patients with residual/recurrent intracranial aneurysms post-surgical clipping treated with flow diversion between 2013 and 2022 were reviewed. Data on patient demographics, aneurysm characteristics, prior surgical treatment, endovascular intervention, clinical outcome, and follow-up imaging were recorded.

Results Nine patients (56% male) were treated with flow diversion following recurrence/residuum of a previously clipped aneurysm. Seven patients were elective procedures, two were treated acutely following carotid artery rupture during clipping. The mean age was 55. Three patients had hypertension, five were active smokers and four had previous subarachnoid haemorrhage. Aneurysm locations included MCA (n=5), ICA (n=2) ACA (n=1), and PComA (n=1). Mean maximum aneurysm dome diameter was 2.4mm (1.0 – 3.3) and mean maximum aneurysm body diameter was 3.6mm (1.4 – 6.0). Complications included a perforator infarct (n=1), hyperperfusion syndrome (n=1), and groin complications (n=1). All of these responded to medical management and no patient experienced change to baseline mRS upon discharge due to the use of a flow diverter. Eight patients had follow-up with a mean duration of 16.8 months. All patients had complete occlusion (RROC 1) at most recent imaging with no patients requiring re-treatment.

Conclusion Flow diverting treatment of recurrences/residua of previously clipped aneurysms results in high occlusion rates with low rates of mortality and permanent morbidity.

Disclosure of Interest no.