Resident University of Toronto Toronto, Ontario, Canada
Introduction: One potential complication of the use of flow-diverter stents (FDS) for the treatment of intracranial aneurysms is in-stent stenosis (ISS). There is a relative lack of real-world data on this phenomenon, especially in light of newer-generation devices becoming available. The purpose of this study is to therefore assess the incidence of ISS in our patient cohort.
Methods: A retrospective database review was performed to identify all patients who underwent FDS placement for intracranial aneurysm treatment. We excluded cases where a stent-assisted coiling was performed or where FDS was used for dissection, dural arterio-venous fistula, or stenosis. We also excluded patients who had no available follow up. ISS classified as either mild (radiographic evidence of ISS without symptoms or requiring intervention) and severe (radiographic evidence of ISS with symptoms and/or requiring intervention).
Results: We identified 181 patients undergoing FD for aneurysms, of which 154 (85.1%) were females. We did not detect any significant difference between males and females in terms of mean age, aneurysm type (saccular aneurysms most common in both groups: 82.5% vs 70.4%), location of aneurysm (anterior circulation most common in both groups: 77.9% vs 77.8%) or stent type (Pipeline most common both groups: 66.2% vs 48.1%). The overall in-stent stenosis rate was 14.3% (n=22/154) for females and 7.4% (n=2/27) for males, though the difference was not found to be statistically significant. Eight of the 22 females (5.2% overall; mean age: 41.875 years) had a severe stenosis at an average of 8 months follow-up, while one of 2 males (3.7% overall; age 50) had a severe stenosis at 2 months follow-up).
Conclusion : Our findings indicate that young females are exposed to small but clinically significant risk of symptomatic in stent-stenosis requiring intervention post-flow diversion for aneurysm occlusion. This phenomenon deserves further study.
