RESUMEN
OBJECT: This study was undertaken to assess the reliability of aspect ratio (AR: the maximum dimension of the dome/width of the neck of an aneurysm) in predicting aneurysm rupture. The authors sought to evaluate the utility of these measures for differentiating ruptured and unruptured aneurysms. METHODS: Patients were retrospectively selected for this study based on the availability of angiograms and a clear diagnosis of an unruptured or ruptured aneurysm. 106 patients with 140 aneurysms were included. 19 patients harbored only unruptured lesions, 70 patients only ruptured lesions, and 17 both ruptured and unruptured lesions. The size of the aneurysms and their ARs were determined by examining the angiographic films. Patient's age and sex, and the location of the aneurysm were also recorded. RESULTS: The ruptured aneurysms were larger and had greater ARs. The mean size of unruptured aneurysms was 4.94 mm and that of ruptured ones was 5.53 mm; the corresponding mean ARs were 1.50 and 1.96, respectively. The odds ratio for rupture rose progressively only for the AR. Only 38.3% of ruptured aneurysms had an AR less than 1.80 compared with 74.0% of unruptured lesions. The odds of rupture were 28-fold greater when the AR was larger than 2.07 compared with an AR with an AR less than or equal to 1.30. Only 9.3% of ruptured aneurysms had and AR less than 1.30 compared with 48.1% of unruptured lesions. CONCLUSION: A high AR might reasonably influence the decision to treat actively an unruptured aneurysm independent of its maximum size, so great care should be taken for patients with unruptured intracranial aneurysms with AR of more than 1.80.