Re-treatment of residual aneurysms after flow diversion: An experimental study

AimFlow diverters are increasingly used to treat aneurysms, but treatment is not always effective. The management of aneurysms that fail to occlude following flow diversion is problematic. We aimed to reproduce failures in an animal model and study re-treatment with additional flow diverters alone or with flow diverters and liquid embolic agent.Material and methodsTwenty wide-necked aneurysms were created at the carotid-lingual bifurcation in 10 dogs, and were treated with flow diverters 4–6 weeks later. Follow-up angiography was performed at three months. Suitable residual aneurysms were randomly allocated: re-treatment with flow diverters alone (n = 6), or with the injection of liquid embolic between two layers of flow diverters (n = 4) or no re-treatment (n = 2). Angiography was repeated three months later, followed by euthanasia, photography and pathology.ResultsPatent wide-necked aneurysms were produced in 17/20 attempts (85%); three months after flow diversion there were 15/17 (88%) residual aneurys...