OBJECT: Hematoma growth unrelated to aneurysmal rebleeding is recognized as a somewhat common complication following endovascular embolization of ruptured aneurysms, but it is scarcely studied. The aim of this study is to elucidate the possible risk factors for this phenomenon. METHODS: Included in this study were 101 consecutive patients with subarachnoid hemorrhage (SAH) who underwent endovascular embolization for saccular aneurysms at the authors' institution within 72 hours of symptom onset. All endovascular procedures were conducted under intraprocedural systemic anticoagulation. Age, sex, hypertension, type 2 diabetes, preoperative antiplatelet or anticoagulation use, neurological grade, Fisher grade, location and size of the aneurysm, grade of aneurysm occlusion, and timing of the endovascular procedure were retrospectively analyzed to determine the risk factors for hematoma growth unrelated to aneurysmal rebleeding. To determine the clinical significance of this complication, the authors also investigated the risk factors for poor clinical outcome (modified Rankin Scale Scores 3-6 at 30 days after onset). RESULTS: This series included 32 men (31.7%) and 69 women (68.3%) with a mean age ± SD of 65.5 ± 14.0 years. The mean time from onset to endovascular procedure was 12.1 ± 14.0 hours. After the procedure, hematoma growth unrelated to aneurysmal rebleeding occurred in 14 patients (13.9%), 10 of whom required surgical removal of the hematoma and/or ventriculostomy to control intracranial pressure. All 14 patients had an anterior circulation aneurysm and had Fisher Grade 3 or 4 SAH. Ultra-early embolization (conducted within 6 hours after onset), female sex, history of hypertension, and poor neurological grade (World Federation of Neurosurgical Societies Grades IV and V) were significant risk factors for hematoma growth (p < 0.05 for all, univariate logistic analysis). In multivariate analysis, ultra-early embolization (OR 18.0 [95% CI 3.26-338], p < 0.001) and female sex (OR 9.83 [95% CI 1.73-187], p = 0.007) were independent risk factors for this phenomenon. Anterior circulation aneurysms and Fisher Grade 3 or 4 SAH were also revealed to be significant risk factors (p = 0.02 for each, chi-square test). Furthermore, hematoma growth without aneurysmal rebleeding was determined as an independent risk factor for poor clinical outcome by multivariate logistic analysis (OR 11.8 [95% CI 2.31-87.1], p = 0.002). CONCLUSIONS: Ultra-early endovascular embolization for ruptured cerebral aneurysms under systemic anticoagulation increases the risk of growth of hematomas unrelated to aneurysmal rebleeding. It is important to recognize the risk of this complication and to either reduce the amount of heparin or to refer the patient for direct clipping if appropriate.
OBJECT: Hematoma growth unrelated to aneurysmal rebleeding is recognized as a somewhat common complication following endovascular embolization of ruptured aneurysms, but it is scarcely studied. The aim of this study is to elucidate the possible risk factors for this phenomenon. METHODS: Included in this study were 101 consecutive patients with subarachnoid hemorrhage (SAH) who underwent endovascular embolization for saccular aneurysms at the authors' institution within 72 hours of symptom onset. All endovascular procedures were conducted under intraprocedural systemic anticoagulation. Age, sex, hypertension, type 2 diabetes, preoperative antiplatelet or anticoagulation use, neurological grade, Fisher grade, location and size of the aneurysm, grade of aneurysm occlusion, and timing of the endovascular procedure were retrospectively analyzed to determine the risk factors for hematoma growth unrelated to aneurysmal rebleeding. To determine the clinical significance of this complication, the authors also investigated the risk factors for poor clinical outcome (modified Rankin Scale Scores 3-6 at 30 days after onset). RESULTS: This series included 32 men (31.7%) and 69 women (68.3%) with a mean age ± SD of 65.5 ± 14.0 years. The mean time from onset to endovascular procedure was 12.1 ± 14.0 hours. After the procedure, hematoma growth unrelated to aneurysmal rebleeding occurred in 14 patients (13.9%), 10 of whom required surgical removal of the hematoma and/or ventriculostomy to control intracranial pressure. All 14 patients had an anterior circulation aneurysm and had Fisher Grade 3 or 4 SAH. Ultra-early embolization (conducted within 6 hours after onset), female sex, history of hypertension, and poor neurological grade (World Federation of Neurosurgical Societies Grades IV and V) were significant risk factors for hematoma growth (p < 0.05 for all, univariate logistic analysis). In multivariate analysis, ultra-early embolization (OR 18.0 [95% CI 3.26-338], p < 0.001) and female sex (OR 9.83 [95% CI 1.73-187], p = 0.007) were independent risk factors for this phenomenon. Anterior circulation aneurysms and Fisher Grade 3 or 4 SAH were also revealed to be significant risk factors (p = 0.02 for each, chi-square test). Furthermore, hematoma growth without aneurysmal rebleeding was determined as an independent risk factor for poor clinical outcome by multivariate logistic analysis (OR 11.8 [95% CI 2.31-87.1], p = 0.002). CONCLUSIONS: Ultra-early endovascular embolization for ruptured cerebral aneurysms under systemic anticoagulation increases the risk of growth of hematomas unrelated to aneurysmal rebleeding. It is important to recognize the risk of this complication and to either reduce the amount of heparin or to refer the patient for direct clipping if appropriate.