Endovascular treatment for large (> 10 mm) basilar tip aneurysms: a retrospective case series

Purpose: To report the long-term clinical and angiographic outcomes of the endovascular treatment of large/giant basilar tip aneurysms (BTAs) in our institutions. Methods: We retrospectively reviewed cases of BTA larger than 10 mm that received endovascular treatment between January 2009 and December 2019. Data on the demographic and clinical characteristics and radiologic severity were obtained from the patients’ medical records. The collected clinical follow-up data included neurological evaluation. Magnetic resonance angiography (MRA) was performed 6 to 12 months after the procedure, followed by once every 1 to 2 years as needed. Results: A total of 12 patients with BTA were included in this study. The median age was 60.08 years (27–80 years), and the mean clinical follow-up was 66.78 months (19.00–142.87 months). Almost half of the patients presented with unruptured BTAs (58.33%, n = 7). The median maximum aneurysm diameter was 13.00 mm (10.46–20.90 mm) and the mean neck size was 8.34 mm (4.82–13.04 mm). A Modified Raymond Roy Classification (MRRC1) of 1 or 2 was observed in 66.67% of the patients (n = 8) immediately after the first procedure. Procedural morbidity and mortality were 33.33% and 8.33%, respectively. Major recanalization occurred in two patients, one of whom underwent additional coiling with the other being merely observed due to older age. Conclusion: It is very difficult to cure a large BTA completely at once and recanalization occurred often after endovascular treatment. Conducting long-term follow-up studies at short intervals is warranted, as well as improving existing treatment methods and developing new approaches.