Long-Term Rupture Risk in Patients with Unruptured Intracranial Aneurysms Treated with Endovascular Therapy: A Systematic Review and Meta-Analysis

• Published in: American journal of neuroradiology : AJNR 2020-06, Vol.41 (6), p.1043-1048
• Main Authors: Rizvi, A, Seyedsaadat, S M, Alzuabi, M, Murad, M H, Kadirvel, R, Brinjikji, W, Kallmes, D F
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aneurysm, Ruptured - epidemiology; Embolization, Therapeutic - methods; Endovascular Procedures - methods; Female; Humans; Interventional; Intracranial Aneurysm - therapy; Male; Middle Aged; Rupture, Spontaneous - epidemiology; Treatment Outcome
• ISSN: 0195-6108; 1936-959X
• DOI: 10.3174/ajnr.A6568

Surveillance imaging of previously unruptured, coiled aneurysms remains routine even though reports of rupture of these aneurysms are extremely rare. We performed meta-analysis to examine long-term rupture risk over ≥1-year follow-up duration in patients with unruptured intracranial aneurysm who underwent endovascular therapy. Multiple databases were searched for relevant publications between 1995 and 2018. Studies reporting outcome of long-term rupture risk over ≥1-year follow-up in treated patients with unruptured intracranial aneurysms were included. Random effects meta-analysis was used, and results were expressed as long-term rupture rate per 100 patient-year with respective 95% CIs. For ruptured aneurysms during follow-up, data were collected on size and completeness of initial Treatment. Twenty-four studies were identified. Among 4842 patients with a mean follow-up duration of 3.2 years, a total of 12 patients (0.25%) experienced rupture of previous unruptured intracranial aneurysms after endovascular treatment. Nine of these 12 patients harbored aneurysms that were large, incompletely treated, or both. A total of 2 anterior circulation, small, completely coiled aneurysms subsequently ruptured. The long-term rupture rate per 100 patient-year for unruptured intracranial aneurysms treated with endovascular therapy was 0.48 (95% CI, 0.45-0.51). Retreatment was carried out in 236 (4.9%) of these 4842 patients. A limitation of the study is that a lack of systematic nature of follow-up and mean follow-up duration of 3.2 years are not sufficient to make general recommendations about aneurysm followup paradigms. Given a 5% retreatment rate, postcoil embolization spontaneous rupture of previously unruptured, small- and medium-sized, well-treated aneurysms is exceedingly rare.