Demographic and anatomical comparison of ruptured and unruptured intracranial aneurysms: a case control study

Background: Our understanding of the pathophysiology and management of intracranial aneurysms (IAs) continuously advances. This case-control study analyzed the demographics of patients with IAs and the morphological Digital Subtraction Angiography (DSA) characteristics of ruptured and unruptured IAs.Methods: Two patient groups with saccular ruptured and unruptured IAs eligible for coiling were prospectively analyzed during a 3-year period. Patient groups were compared regarding gender, age, arterial vasculature side, anatomical location, diameter, preoperative DSA appearance, aneurysmal and anatomical Circle of Willis variations (CWV) coexistence.Results: One hundred and three patients with ruptured and eighty-six patients with unruptured IAs were studied. Anterior communicating and internal carotid artery IAs were the dominant locations: 42.7 % and 23.3 % in ruptured and 29 % and 41.9 % in unruptured IAs, respectively. The female-to-male ratio was 1.78 in ruptured and 2.44 in unruptured IAs (p =0.317), while the rupture was more frequent in younger patients (p =0.034). Angiographically, smaller diameter (p =0.01), abnormal morphology (p =0.0001), and co-existence of CWV (p =0.016) were reported in ruptured IAs. Location at bifurcation/trifurcation (p =0.487) and the co-existence of additional or mirror IA did not differ significantly (p =0.879). Conclusions: On DSA, ruptured and unruptured IAs differed in size, morphology, and co-existence of CWV; findings that may favor the treatment of specific unruptured IAs. However, a higher level of evidence is needed to include all these factors in the treatment decision process, provide patient-oriented treatment and reliably identify unruptured IAs at greater risk. HIPPOKRATIA 2021, 25 (3):100-107.