Original ArticlePredictors of Occurrence and Anatomic Distribution of Multiple Aneurysms in Patients with Aneurysmal Subarachnoid Hemorrhage
Introduction
Aneurysm formation likely results from a combination of genetic predisposition, acquired degenerative changes, and local hemodynamic stresses. Known risk factors for aneurysm formation include constitutional factors, such as female sex, age >60 years, and genetic or acquired diseases, such as polycystic kidney disease and diabetes mellitus.1 Multiple intracranial aneurysms (MIA) are found in 20%–33% of patients with aneurysmal subarachnoid hemorrhage (aSAH).2, 3 Predisposing factors for MIA include female sex, higher body mass index, smoking, and black race.4, 5, 6 In contrast to single intracranial aneurysm (SIA), hypertension and a family history of cerebrovascular disease have been associated with aneurysm multiplicity.1, 4
The available literature on MIA in patients suffering from aSAH consists largely of retrospective cohort studies of limited sample size and studies in populations outside Europe and North America.1, 4, 7 Only a few registries offer the combination of a dedicated nationwide all-inclusive registration of patients with aSAH with highly detailed data acquisition that is not part of more general stroke registries.8, 9, 10, 11, 12, 13 High-quality datasets comprising a large number of unselected patients, such as the Swiss Study on Subarachnoid Hemorrhage (SOS) registry, offer opportunities for epidemiologic research with increased accuracy and statistical power. Consequently, we expect our data to provide a more solid epidemiologic basis than earlier studies, and we anticipate that our findings will eventually apply to all Western countries with typical aging demographics and a similar health care system, meaning universal access and coverage. In sum, the purpose of this cohort study was to determine the predictors of occurrence and to investigate the anatomic distribution of MIA in a representative central European cohort of patients with aSAH.
Section snippets
Patient Registry
The SOS registry is a multicenter cohort database containing core data that are collected prospectively in a standardized manner. It is managed independently by each participating center. The registry was initiated in 2009; study details have been published elsewhere.14 Internal Review Board and Ethical Committee approval was obtained for all participating centers (under the supervision of the Geneva Ethical Committee; no. 11-233R, NAC 11-085R). Most local Ethics Committees waived the
Study Population
The locked SOS dataset for 2009–2014 includes data from a total of 1787 patients, of whom 1313 had SIA (73.5%) and 474 had MIA (26.5%). Of these, 1689 patients met the inclusion criteria for the present study, including 1222 with SIA (72.4%) and 467 (27.6%) with MIA (Supplemental Figure 1).
Predictors of Aneurysm Multiplicity and Anatomic Distribution
Ruptured anterior communicating artery (ACoA) aneurysms were the most common aneurysms in the patients with SIA, and middle cerebral artery (MCA) aneurysms were the most common ruptured aneurysms (index
Discussion
In this large nationwide cohort study, the location of the ruptured aneurysm (index aneurysm) was the single strongest predictor for the presence of additional aneurysms (Supplemental Figure 2). In addition, we found evidence of aneurysm clustering, with the location of the index aneurysm as a strong independent predictor for the likely anatomic distribution of bystander aneurysms (Table 2 and Supplemental Tables 2 and 3). Other independent predictors for MIA included female sex and larger
Conclusions
Ruptured aneurysms arising from such locations as the MCA, BA, and PCoA are more common in females than males. They tend to be larger at the time of rupture, and more often present with aneurysm multiplicity. Thus, imaging workups in patients with aSAH who harbor an index aneurysm at one of these locations should include extra-careful screening for additional aneurysms, especially at the sites at which bystander aneurysms can be expected to occur.
Acknowledgments
We thank Ethan Taub, MD, for reviewing the manuscript, Selina Ackermann for providing editorial assistance, and David Lucco for anatomical illustration (Figure 2). Further members or collaborators of the Swiss SOS Study Group that contributed to the study include: Javier Fandino, Daniel Colluccia, Marta Arrighi, Alice Venier, Dominique E. Kuhlen, Thomas Robert, Michael Reinert, Astrid Weyerbrock, Martin Hlavica, Jean-Yves Fournier, Andreas Raabe, Juergen Beck, David Bervini, Karl Schaller, Roy
References (29)
- et al.
Aneurysmal subarachnoid hemorrhage in a Mexican multicenter registry of cerebrovascular disease: the RENAMEVASC study
J Stroke Cerebrovasc Dis
(2009) - et al.
Spontaneous subarachnoid hemorrhage multicenter database from the Group for the Study of Vascular Pathology of the Spanish Society for Neurosurgery: presentation, inclusion criteria and development of an internet-based registry
Neurocirugia (Astur)
(2008) - et al.
Subarachnoid Hemorrhage International Trialists data repository (SAHIT)
World Neurosurg
(2013) - et al.
Size of cerebral aneurysms and related factors in patients with subarachnoid hemorrhage
Surg Neurol
(2004) - et al.
Unruptured intracranial aneurysms: natural history, clinical outcome, and risks of surgical and endovascular treatment
Lancet
(2003) - et al.
Prevalence of unruptured intracranial aneurysms, with emphasis on sex, age, comorbidity, country, and time period: a systematic review and meta-analysis
Lancet Neurol
(2011) - et al.
Risk factors for the formation of multiple intracranial aneurysms
J Neurosurg
(2001) Risk factors for multiple intracranial aneurysms
Stroke
(2000)- et al.
Patient and aneurysm characteristics in multiple intracranial aneurysms
Acta Neurochir Suppl
(2008) - et al.
Risk factors for multiple intracranial aneurysms
Neurosurgery
(1998)
Factors associated with aneurysm size in patients with subarachnoid hemorrhage: effect of smoking and aneurysm location
Neurosurgery
Demographic and clinical predictors of multiple intracranial aneurysms in patients with subarachnoid hemorrhage
J Neurosurg
Relation between age and number of aneurysms in patients with subarachnoid haemorrhage
Cerebrovasc Dis
The Subarachnoid Hemorrhage International Trialists (SAHIT) Repository: advancing clinical research in subarachnoid hemorrhage
Neurocrit Care
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Conflict of interest statement: This work was supported by departmental funds from the Department of Surgery, Basel University Hospital, University of Basel, Basel, Switzerland. The Basel Institute for Clinical Epidemiology and Biostatistics receives funding from Stiftung Institut für klinische Epidemiologie.