Ruptured Very Small Cerebral Aneurysms and the Usefulness of Coil Embolization

Abstract

Objective: Cerebral aneurysms larger than 7 mm are considered at risk for rupture. The International Study of Unruptured Intracranial Aneurysms (ISUIA)-1 (1998) and ISUIA-2 (2003) suggested that there is a negligible risk of subarachnoid hemorrhage (SAH) in aneurysms larger than 7 mm. However, smaller cerebral aneurysms are also at risk for rupture. We analyzed patients with spontaneous SAH due to the rupture of cerebral aneurysms smaller than 3 mm.Methods: From January 2019 to June 2022, seven patients were diagnosed with spontaneous SAHs with ruptured saccular aneurysms smaller than 3 mm and treated with coil embolization. Age, sex, location, hypertension, and smoking were analyzed as possible risk factors, and complications based on radiological findings and clinical outcomes after coil embolization were assessed to evaluate treatment. Results: The seven patients analyzed during this 3-year period ranged in age from 43 to 80 years (five women and two men). The saccular aneurysms were located in the anterior and posterior circulation. Four patients were diagnosed with hypertension, and three patients were smokers. Successful coil embolization involving subtotal occlusion with a remnant neck was done in all seven patients, and there were no complications.Conclusion: Ruptured aneurysms smaller than 3 mm can be successfully treated with coil embolization.