Unruptured intracranial aneurysms: development, rupture and preventive management

Abstract

Saccular unruptured intracranial aneurysms (UIAs) have a prevalence of 3% in the adult population, and are being increasingly detected because of improved quality and higher frequency of cranial imaging. Large amounts of data, providing varying levels of evidence, have been published on aneurysm development, progression and rupture, but less information is available on the risks and efficacy of preventive treatment. When deciding how to best manage UIAs, clinicians must consider the age and life expectancy of the patient, the estimated risk of rupture, the risk of complications attributed to preventive treatment, and the level of anxiety caused by the awareness of having an aneurysm. This Review highlights the latest human data on the formation, progression and rupture of intracranial aneurysms, as well as risks associated with preventive treatment. Considering these we discuss the implication for clinical management. Furthermore, we highlight pivotal questions arising from current data on intracranial aneurysms and the implications the data have for future experimental or clinical research. We also discuss data on novel radiological surrogates for rupture for those aneurysms that do not require preventive occlusion. Finally, we provide guidance for clinicians who are confronted with patients with incidentally detected UIAs.

PHASES Score for the Management of Intracranial Aneurysm

“…3 Overall, the average risk of rupture of UIA is estimated between 0.3% and >15% per 5 years (0.4-0.6 for lesions smaller than 7 mm). 1 Preventive treatment of these aneurysms exposes patients to a risk of 1% mortality and ≈5% morbidity (<0.1% and <3%, respectively, for small lesions). [4][5][6] The balance between risks and benefits on different management options needs to be personalized.…”

Saccular Intracranial Aneurysms in Children When Both Parents Are Sporadic or Familial Carriers of Saccular Intracranial Aneurysms

“…Assuming a general prevalence of 1-3% for the IA disease [4,5,9], the 3,659 couples would include some 37-110 couples concordant for a diagnosed or undiagnosed IA disease. However, we identified only 18 such couples (0.4%), 6 familial-sporadic couples and 12 sporadic-sporadic couples with altogether 48 children.…”

“…The IA disease is affected by age, female gender, smoking, hypertension, and, rarely, (1%) autosomal dominant polycystic kidney disease [5,6]. Like many other complex traits, the IA disease also clusters in families [5,[7][8][9], but currently known genomic variants explain only a fraction of the IA heritability [10].…”

“…Like many other complex traits, the IA disease also clusters in families [5,[7][8][9], but currently known genomic variants explain only a fraction of the IA heritability [10]. Approximately 10-20% of IA patients belong to an IA family [8,11].…”

“…About 3% of the general population develops IA disease, but most IAs are too small to cause neurological symptoms, do not rupture, and go unnoticed during life [4,5].…”