Introduction: Both the size and location of unruptured intracranial aneurysms have been frequently researched in the last decades. However, little is known about ruptured intracranial aneurysms (RIAs). In this study, we thus aimed to verify whether the size of RIAs affects prognosis and clinical features.
Material and Methods: A total of 185 patients with RIAs, who were treated in our hospital between September 2008 and December 2015, were analyzed in the present study. Specifically, the relationship between the size of the RIA and the operative outcome (mRS) was investigated. Furthermore, the incidence of complications associated with operative procedures depending on the aneurysmal size was also evaluated. Finally, we analyzed the relationship between the size of RIAs and their location, patients’ sex and age, surgical procedure (clip or coil), severity on admission (GCS), and frequency of intracranial hemorrhage (ICH), intraventricular hemorrhage (IVH), and cerebral vasospasm.
Results: The average maximum diameter of RIAs was significantly larger in males than females (6.7 and 5.6 mm, respectively; p = 0.012), in patients with ICH than in those without it (6.6 and 5.6 mm, respectively; p = 0.042), and in the poor outcome group (mRS = 3-6) than in the good outcome one (mRS = 0-2) (6.65 and 5.5 mm, respectively; p = 0.003). Furthermore, MCA RIAs were significantly larger than RIAs located in the posterior circulation (6.6 and 4.2 mm, respectively; p <0.05). Subsequently, the 185 patients were divided into two groups, namely the good and poor outcome groups, to analyze the prognostic factors. Our results indicated the following to be independent poor prognostic factors: advanced age (55.3 vs 28.6%; OR: 0.269; CI: 95%; 0.127-0.569), IVH (76.7 vs 35.5%; OR: 0.24; CI: 95%; 0.0837-0.688), GCS ≦13 (66.7 vs 18.9%; OR: 0.226; CI: 95%; 0.101-0.508), and RIAs of size ≧6 mm (50.5 vs 32.6%; OR: 0.468; CI: 95%; 0.222-0.99, p = 0.047). With regards to the incidence of complications associated with operative procedures depending on the aneurysmal size, the following factors were not significantly different between the two groups: (<6 mm and ≧6 mm: intraoperative aneurysmal rupture (9.3 vs 11.1%; p = 0.872), infarctions (9.3 vs 9.1%; p = 0.837), and contusions (1.2 vs 6.1%; p = 0.175).
Finally, the 185 patients were additionally divided into two further groups based on their aneurysmal size (either ≧6 or ≦6 mm) to compare their clinical features. A univariate analysis suggested the RIAs located on the MCA to be likely to grow larger than 6 mm compared to those placed elsewhere. In contrast, multivariate analysis indicated the male parameter to be the only independent factor to be correlated with an aneurysmal size ≧6 mm.
Conclusion: RIAs of a size ≧6 mm appear more frequently in males and result in poor outcome.