The likelihood of rupture of unruptured intracranial aneurysms that were less than 10 mm in diameter was exceedingly low among patients in group 1 and was substantially higher among those in group 2. The risk of morbidity and mortality related to surgery greatly exceeded the 7.5-year risk of rupture among patients in group 1 with unruptured intracranial aneurysms smaller than 10 mm in diameter.

Background and Purpose-To explore relationships among gender, body size, neck size, and the diameters of the common carotid artery (CCA) and internal carotid artery (ICA). Methods-Using multivariate regression, the best predictors of sonographic diameters of CCA and ICA were determined based on age, height, weight, body mass index, body surface area, neck circumference, neck length, and blood pressure. Results-Measurements were obtained in 500 consecutive patients (age 52Ϯ15 years; 61% women). Mean diameters of ICA (4.66Ϯ0.78 mm) and CCA (6.10Ϯ0.80 mm) in women were significantly smaller than in men: 5.11Ϯ0.87 mm and 6.52Ϯ0.98 mm, respectively. Sex significantly influenced the diameters after controlling for body size, neck size, age, and blood pressure. Conclusions-Carotid arteries are smaller in women even after adjusting for body and neck size, age, and blood pressure.

Adeno-associated virus serotype 9 (AAV9) vectors have recently been shown to transduce cells throughout the central nervous system of nonhuman primates when injected into the cerebrospinal fluid (CSF), a finding which could lead to a minimally invasive approach to treat genetic and acquired diseases affecting the entire CNS. We characterized the transduction efficiency of two routes of vector administration into the CSF of cynomolgus macaques—lumbar puncture, which is typically used in clinical practice, and suboccipital puncture, which is more commonly used in veterinary medicine. We found that delivery of vector into the cisterna magna via suboccipital puncture is up to 100-fold more efficient for achieving gene transfer to the brain. In addition, we evaluated the inflammatory response to AAV9-mediated GFP expression in the nonhuman primate CNS. We found that while CSF lymphocyte counts increased following gene transfer, there were no clinical or histological signs of immune toxicity. Together these data indicate that delivery of AAV9 into the cisterna magna is an effective method for achieving gene transfer in the CNS, and suggest that adapting this uncommon injection method for human trials could vastly increase the efficiency of gene delivery.