Intraprocedural Technical Events During Flow Diverter Implantation Partially Mediate the Effect of Age on Aneurysm...

Flow diverters (FDs) are the first line of treatment for specific intracranial aneurysms. However, aneurysm persistence at follow-up presents in up to 25%. Occlusion after flow diversion in older patients seems less effective due to clinical, anatomical, and physiological characteristics. We aimed to study the effect of age on aneurysm occlusion mediated by intraprocedural technical events.

We conducted a pooled analysis of 2 cohorts, including patients with unruptured saccular aneurysms in the internal carotid artery, treated with the Surpass Streamline FD. Multivariable logistic regression was used to identify predictors of complete occlusion at 12-month follow-up. A mediation analysis was performed to assess the role of intraprocedural technical events (eg, fish-mouthing of the distal end, poor device opening, FD twisting, foreshortening, excess friction of the FD and the delivery system during deployment, and delivery system kink) in the relationship between age and occlusion rates.

A total of 316 patients (mean age 59.4 ± 11.2 years) were included. Complete aneurysm occlusion was achieved in 82% of cases at 12 months. Increasing age was associated with lower odds of occlusion (adjusted odds ratio = 0.962, P<0.001) and a higher incidence of intraprocedural technical events (adjusted odds ratio = 1.088, P<0.001). Intraprocedural technical events were inversely associated with occlusion (adjusted odds ratio = 0.265, P = 0.004), and mediation analysis revealed that 16.3% of the effect of age on aneurysm occlusion was mediated by these events.

Intraprocedural technical events partially mediate the effect of age on complete aneurysm occlusion after FD treatment. Identifying additional mechanisms that influence occlusion could improve procedural outcomes, particularly in older patients.