Zenichiro Watanabe

Comparison of Rates of Growth between Unruptured and Ruptured Aneurysms Using Magnetic Resonance Angiography

BACKGROUND AND PURPOSE Growth is a key risk factor for rupture of unruptured cerebral aneurysms. There are few reports of investigations into the actual growth of ruptured intracranial aneurysms. The aim of the present study was to ascertain the risk of rupture of aneurysms based on the growth of unruptured and ruptured aneurysms. METHODS Changes in size on magnetic resonance angiography (MRA) were examined in 50 patients with ruptured cerebral aneurysms. Images obtained before and after subarachnoid hemorrhage were used. Moreover, changes in aneurysm size were retrospectively examined in 73 patients with 100 unruptured cerebral aneurysms that were followed serially with MRA that was performed using a 1.5-T or 3-T system. The size of the aneurysm was determined by measuring the maximum diameter on maximum intensity projection MRA images. Based on these data, the annual growth rates (mm growth/year) of unruptured and ruptured aneurysms were calculated and compared. RESULTS The median annual growth rate of ruptured aneurysms was significantly greater than that of unruptured aneurysms (.69 versus .077 mm/year, P < .01). The annual growth rates of ruptured aneurysms showed a negative correlation between the duration from initial MRA to the time of rupture. CONCLUSION A high annual growth rate is a key risk factor for aneurysm rupture. This finding provides strong evidence for the treatment of unruptured cerebral aneurysms.

Effect of age on local intra-arterial thrombolysis for acute middle cerebral artery occlusion

Abstract Objective: We evaluate the effects of age on local intra-arterial thrombolysis for acute middle cerebral artery (MCA) occlusion, and assign its treatment role in aged patients. Methods: We performed local intra-arterial thrombolysis within 6 h of onset in 40 patients who presented with acute MCA occlusion. We treated these patients based on their neurological states and diffusion-weighted MRI findings. Their neurological states were evaluated using the National Institute of Health Stroke Scale (NIHSS) at admission and immediately after the treatment. We evaluated the outcome using the modified Rankin Scale (mRS) at discharge. We analyzed the relationship of age and recanalization rate, hemorrhagic complication and outcomes. Results: In all patients, the rate of recanalization was 77.5%. The recanalization rate in patients aged 80 years or older was significantly lower (50%) than in the patients who were less than 80 years old (82.3%). Hemorrhagic complications occurred in three patients, all under 75 years old. Of all the patients, 21 patients (52.5%) had a good outcome (mRS 0–2). Among the 28 patients who exhibited recanalization of the MCA, 21 patients under 80 years old (75%) experienced a good outcome. In spite of recanalization of the MCA, there were no good outcomes in the patients aged 80 years or older. Conclusion: Local intra-arterial thrombolysis for acute MCA occlusion is efficient for the patients under 80 years old. But in patients aged 80 years or older, the recanalization rate is significantly low and the outcome is poor even in patients having had recanalization of the MCA performed. So, we should consider the indication of local intra-arterial thrombolysis for patients over 80 years old.