Introduction: Since the publication of the ISUA study, treatment of small unruptured aneurysms measuring < 7 mm has been conservative management. Nevertheless, over the last 4 years, 6 unruptured saccular aneurysms each measuring < 7mm have ruptured.
Methods: From a prospectively acquired aneurysm database, 6 aneurysms < 7mm treated conservatively that ruptured were identified. Significant associations among presentation, aneurysm characteristics, and outcomes were analyzed.
Results: Six conservatively managed patients with unruptured aneurysms ranging from 2-5 mm were found to have a subsequent subarachnoid hemorrhage. The mean age was 62.3 years (range, 43-85 years) including 4 women and 2 men. Aneurysm locations were anterior communicating artery region (2), posterior communicating artery (2), internal carotid bifurcation (1), and posterior inferior cerebellar aneurysm (1). Hypertension was the most common comorbidity with an incidence of 50%. One-third were smokers. Half had multiple aneurysms. One-third of the patients had a family history of a ruptured aneurysm. No patient experienced a warning leak. Of the 3 patients with serial imaging, none had changes in characteristics of the corresponding aneurysm. Half were treated coil embolization, and the other half with clip ligation. One patient had a previously ruptured aneurysm that was clipped. Average admission Hunt-Hess score was 2.3. Average Glasgow outcome score was 4 at discharge. No perioperative mortalities occurred.
Conclusions: Aneurysms <7 mm are frequently treated conservatively; however, over a 4 year period 6 aneurysms being followed conservatively ruptured. The rupture rate for aneurysms < 7mm may be higher than once thought.
Patient Care: This research increases the awareness that it is possible that aneurysms < 7 mm can rupture and should be followed closely
Learning Objectives: Aneurysms < 7mm followed conservatively do rupture.