Endovascular and microsurgical management of blister aneurysms: a multi-centre review

Background Blister aneurysms (BA) are high risk cerebrovascular lesions accounting for 1% of intracranial aneurysms. The defective vessel wall and broad-based neck make this clinical entity difficult to treat, with high rates of re-rupture and mortality in patients presenting with acute subarachnoid haemorrhage. Blister aneurysms pose substantial challenges for both endovascular and microsurgical management.Objective To evaluate endovascular and microsurgical outcomes in intracranial blister aneurysm management across two tertiary hospitals.Methods A review of two tertiary hospitals with a systematic imaging database search for term of “blister” in modalities from January 2010 to October 2022. Operation reports were screened for the 5-year period since cerebral angiogram reports transitioned to surgical database. Identified reports were screened and reviewed for confirmed diagnosis by consultant neuroradiologist.Results 21 cases of blister aneurysms managed at respective facilities were included. 16 cases (76%) were managed endovascularly – all with flow diversion stents. 4 cases (19%) were managed surgically – 2 with primary clipping, and 2 wrap and clipping. 1 case was managed conservatively (5%). Clinical outcomes were discharge disposition, aneurysm exclusion and post-operative complications.Conclusion BAs have challenging considerations with high mortality and morbidity. Endovascular treatment is less invasive option with lower rates of intraoperative rupture and mortality. Patients discharged home were comparable. Commencement of dual anti-platelet therapy was safe in patients with flow diversion stents despite sub-arachnoid blood volume. Management of blister aneurysms is complex. Endovascular treatment shows promise for acute treatment but careful consideration of antithrombotic regime and requirement for further surgery should be considered.