Quadruple coaxial catheter system on transvenous embolization for dural arteriovenous fistula

Background: Although transvenous embolization (TVE) is an effective method for treating dural arteriovenous fistula (AVF), directing the catheter to the lesion site is difficult.Objective: We report on the utility of a quadruple coaxial catheter system for TVE.Materials and methods: The quadruple catheter system comprised a 6 Fr guiding sheath, 6 Fr guiding catheter, 4 Fr intermediate catheter, and a regular microcatheter. The system was utilized in 27 consecutive dural AVF cases treated with TVE. In this study, we reviewed our experience with this system, including the theory, method of use, and complications.Results: Stenosis or obstruction of the vascular access was identified in 12 cases. The catheter could not reach to the lesion in three cases of cavernous sinus (7.4%); therefore, transarterial embolization was employed. Angiographic results revealed that the cases consist of total occlusion (n = 16, 59.5%), subtotal (n = 10, 37.0%), and partial occlusion (n = 1, 3.7%). Complete resolution or improvement of symptoms was observed in 23 patients (85.2%), no improvement of symptoms was observed in three patients (7.4%), and deterioration of symptoms was observed in one patient (3.7%). Venous perforation occurred in one patient without any neurological deficit. The catheter system provided access to the lesion and provided stability during the mechanically demanding process navigating the catheter and placing the coils.Conclusion: We determined that the quadruple coaxial system was safe and efficient for TVE for dural AVF

Pathophysiology of flow impairment during carotid artery stenting with an embolus protection filter

Objective: Carotid artery stenting (CAS) is a well-accepted treatment for atherosclerotic stenosis of carotid arteries. Since the occurrence of distal embolization with CAS is still a major concern embolus protection devices (EPD) are usually employed during the procedure. We examined two types of embolus protection filters (Angioguard XP (AG); Filterwire EZ (FW)) and evaluated the function. Thus, the filter was examined postoperatively and the cause of intraoperative flow impairment was evaluated. Materials and methods: CAS was performed for 54 patients with carotid artery stenosis (55 lesions: 25 AG; 27 FW; 3 others). After completing CAS the filter membrane was stained with hematoxylin-eosin (HE) solution and removed from the filter strut. Once mounted on a glass slide the filter was evaluated under a microscope. The area occupied with debris was measured and the relationship to intraoperative flow impairment was evaluated. Furthermore, the relationship between perioperative ischemic complications and intraoperative flow impairment was statistically analyzed. Results: Microscopic observation of the slide revealed the pore density of the FW was 1.5 times higher than that of the AG and the filter area of the FW was 2.5 times wider than than the AG. HE staining facilitated characterization of the debris composition. The area occupied with debris was significantly more in the AG (0.241 ±0.13 cm2) than in the FW (0.129 ±0.093 cm2). Thus, fibrin was significantly more precipitated in the AG. Flow impairment occurred in 6 AG cases (24.0 %) and 4 FW cases (14.8 %). It was induced by filter obstruction in the AG and by vasospasms in the FW. Three cases treated with AG (12.0 %) were complicated with cerebral infarction and all of them were related to flow impairment. One FW case (3.7 %) was complicated with cerebral infarction in presence of preserved flow throughout the intervention. Conclusion: Filter function is different according to each design. The cause of flow impairment was attributable to filter obstruction in the AG group and to vasospasms in the FW group. Filter obstruction tends to result in cerebral infarction

Fertility decline in Japan since the 1970s

This study investigates the influence of socio-economic and attitudinal factors on recent changes in marriage and fertility in Japan. Using macroand micro-data (collected especially for this research), the study examines the validity of three main theories: (1) the New Home Economics theory; (2) Easterlin's theory; and (3) the ideational (or attitudinal) theory in detemining Japanese marriage and fertility behaviour. The findings of this study show that socio-economic factors exert a substantial effect on Japanese marriage and fertility behaviour. More specifically, an increase in women's earning capacity raised their marriage age, lowered the level of their fertility, and lengthened their birth intervals. This evidence is in agreement with the New Home Economics theory. On the other hand, relative economic status also affected Japanese marriage and fertility behaviour. An improvement in the economic situation of young adults encouraged them to marry earlier, and to have more children. These findings support Easterlin's theory. However, comparing the two theories, the longitudinal trend of marriage and fertility pattern in Japan is better explained by the New Home Economics theory than Easterlin's theory. The level of women's wages had a relatively stronger impact on these patterns than their relative economic status. The findings also reveal that attitudinal factors play a significant role in determining Japanese marriage and fertility behaviour. As women became less committed to traditional norms and values, they married later, had fewer children and lengthened their birth intervals. Likewise, the reinforcement of women's individualistic attitudes raised their marriage age, lowered the level of their fertility, and delayed their entry to parenthood. This evidence indicates that marriage and fertility pattern in Japan cannot be due entirely to socio-economic factors. Comparing socio-economic and attitudinal factors, the former had a greater influence on marriage and fertility behaviour than the latter. We conclude from the findings of this study that Japanese marriage and fertility behaviour are affected both by socio-economic and attitudinal (ideational) factors, but the influence of the latter is secondary.</p