gms | German Medical Science

Objective: Studies on contrast uptake in aneurysm walls raised the hypothesis that contrast enhancement and hence rupture risk of aneurysms may not only depend on aneurysm size, but also on the relation of aneurysm and parental vessel diameter. We therefore examined the distribution of aneurysm sizes in relation to their parental vessel in a patient collective of ruptured aneurysms.

Methods: We retrospectively identified patients admitted to our neurosurgical department between 01.03.2010 and 31.07.2016 with the diagnosis of spontaneous subarachnoid hemorrhage. In cases with confirmed ruptured aneurysm, the CTA scan performed upon admission was taken to determine (i.) location and (ii.) diameter of the ruptured aneurysm, and (iii.) the diameter of the parental vessel in the proximity of the aneurysm. ANOVA was used for statistical testing.

Results: 279 patients were identified, 246 of which were diagnosed with a ruptured aneurysm. In 94 patients the aneurysm was located at the anterior cerebral artery (ACA), in 60 at the internal carotid artery (ICA), in 54 at the middle cerebral artery (MCA) and in 38 at the posterior circulation (PC). Mean parental vessel diameters at the ACA were significantly (p<0.05) smaller compared to the other locations (ACA: 1.94±0.49 mm; ICA: 2.64±0.79 mm; MCA: 2.06±0.48 mm; PC 2.35±1.23 mm). In contrast, the mean diameters of the aneurysms (ACA: 6.39±2.53 mm; ICA: 7.17±4.19 mm; MCA: 7.02±4.1 mm; PC: 7.68±3.99 mm) as well as the ratios of aneurysm diameter to parental vessel diameter (ACA: 3.42±1.47; ICA: 2.96±1.98; MCA: 3.56±1.95; PC: 3.48±1.71) were not significantly different.

Conclusion: In our collective, the diameter of the parental vessel apparently does not influence aneurysm rupture risk. Future studies on collectives with unruptured aneurysms will be needed for further clarification.