gms | German Medical Science

Objective: Since the ISUIA studies most of the aneurysms were removed from consideration of treatment solely because their maximal size is <10 mm or 7 mm. Our clinical impression was that a substantial part of our patients have subarachnoid hemorrhage (SAH) from aneurysms with a maximum diameter <7 mm and consequently experience irreparable morbidity and severe mortality. The majority of their aneurysms were, of course, unruptured, single, asymptomatic, and even smaller at some point before rupture.

Methods: In order to evaluate our clinical impression we reviewed the clinical records of 166 patients admitted to our hospital suffering from acute SAH over a two-year-period of time and the records of patients admitted for unruptured intracranial aneurysms (UIA) until 1999 (63 patients).

Results: The aneurysm size in the UIA was 9 mm on average and the size in the ruptured aneurysm group 7,2 mm. This difference did not reach statistical significance. However there was a trend indicating that the UIA’s were larger than the ruptured aneurysms at a time where all aneurysms regardless of size were treated in our institution. Further analysis revealed statistically significant differences regarding the known risk factors of aneurysm rupture such as hypertension p<0.02, localization p<0,001, pathologic body mass index p<0,001. Smoking did not reach statistical significance in our group.

Conclusions: We do not have a population based study and therefore we do not know the exact incidence of unruptured intracranial aneurysms and we do not know their size. But taking the relatively high number of ruptured aneurysms smaller than 8 mm (38%) into account a need for such a study becomes obvious. Furthermore treatment of small unruptured aneurysms might be still feasible in the individual patient, especially when risk factors are present.