Support and guide performance comparison of balloon guide catheters.

Background: Several types of balloon guide catheters (BGCs) are used in mechanical thrombus retrieval. However, direct comparisons of their supporting and guiding performance have not been reported. We compared the supporting and guiding performance of the Branchor, Flowgate, and Optimo BGCs using a type 3 aorta artificial vascular model. Methods: An inner catheter was pushed into the artificial vascular model using a linear actuator for the supporting performance evaluation. A previously placed BGC in the internal carotid artery was then intentionally caused to slip. Supporting performance was evaluated by measuring the distance the BGC slipped and generated maximum resistance during Inner catheter insertion. For the guiding performance experiment, a linear actuator was used to guide the BGC into the internal carotid artery of the artificial vessel model. The guiding performance was evaluated by measuring the distance reached by the BGC, maximum resistance generated during insertion of the guiding catheter, and distance the inner catheter slipped. Each experiment was replicated 5 times. Results: No statistically significant differences were observed in the results of the five supporting performance experiments. However, the results of the first and second experiments suggested that the Optimo offers better supporting performance. In the guiding performance experiment, significant differences were observed, suggesting that the Branchor and Flowgate have superior guiding performance in comparison with the Optimo. Conclusion: The Optimo offered superior supporting performance, while the Branchor and Flowgate showed better guiding performance than the Optimo.

Experimental Safety Evaluation of Inflated Assisting Balloons for Endovascular Surgery.

Objective: The balloon-assisted technique is one of the methods used for cerebral aneurysm embolization. There are several applications of assisting balloons such as remodeling the neck of cerebral aneurysms, protecting blood vessel branches, and stabilizing the microcatheter. In this study, we measured the pressure inside inflated assisting balloons to assess safety or procedure. Methods: A T-junction silicone model was used. The pressure inside the balloon inflated to the set herniation levels in the T-junction model was measured using a fiber pressure sensor. We compared the pressure and difference between each assisting balloon. Results: The pressure required for inflating the balloon to the set herniation level in the T-junction model varied depending on the type of assisting balloon. The results suggest that differences in pressure among inflated balloons are likely attributable to differences in the materials used in the lumens of the balloons. Conclusion: The pressure inside various inflated assisting balloons was measured for comparison and differences were found. This experiment contributes to the safety of the balloon-assisted technique.

Treatment of Recurrent Aneurysm of the Internal Carotid Artery-poster Communicating Artery Using the Marathon Microcatheter: A Case Report.

Objective: We report the case of an aneurysm of the recurrent internal carotid artery (ICA)-posterior communicating artery (PCoA) treated using a liquid embolic delivery microcatheter (MC; Marathon). Case Presentation: A 66-year-old female previously presented with subarachnoid hemorrhage, which had been treated using coil embolization for a ruptured ICA-PCoA aneurysm. She was referred to our hospital because the aneurysm recurred 13 years after treatment. Angiography revealed a de novo lobulated aneurysm at the ICA-PCoA bifurcation with a relatively thickened PCoA branching from the neck of the aneurysm. We performed coil embolization after stent placement with the Neuroform Atlas in the range of the ICA terminus and the PCoA. However, the coils were unequally distributed and it was necessary to navigate the MC to the aneurysm within the stent through the PCoA. We successfully approached the aneurysm using the Marathon. We additionally inserted six ED coils into the aneurysm and achieved favorable embolization. Conclusion: The Marathon is useful for passage of a stent deployed in a small-caliber artery.

Optimum coil insertion speed of various coils in brain aneurysm embolization in vitro.

A coil must comprise material with shape memory to perform optimal coil embolization. To achieve this, the alloy characteristics of the coil (hardness, shape, and thickness) must be understood. In this experiment, a catheter was fixed in the bright position and the movement of the coil was observed under a constant rate of insertion; the optimal insertion rate during clinical use was investigated. The first coil insertion speed was evaluated using simulated aneurysms in an in vivo arterial model. The results showed that the insertion force relates to the deployment shape of the coil, that the feedback through the force indicator using sound is very effective, and that the recorder is useful for analysis of coil embolization. The inserted coils during aneurysm embolization were able to wind uniformly within the aneurysm due to a variety of factors (guiding or micro-catheter position and kick-back phenomenon such as delivery wire). Optimal speed is achieved with proper coil design, which allows the coil to be inserted into the aneurysm. The shape and size of the aneurysm can help determine the necessary size and design of the coil that should be used during the optimal speed range. Aneurysm wall and coil characteristics are considered, along with the friction state of the coil (hardness, shape, and thickness), leading to improvements in safety during the insertion procedure at optimum speed.

Does information on health status lead to a healthier lifestyle? Evidence from China on the effect of hypertension diagnosis on food consumption.

We examine the role of information in understanding the differential effects of income on the demand for health. In the health capital framework of Grossman (JPE, 1972), we derive the testable hypotheses that individuals adjust their diet in a healthier direction upon receiving negative health information, and that the effect is greater for richer individuals. Based on unique Chinese longitudinal data and a regression discontinuity design that exploits the exogenous cutoff of systolic blood pressure in the diagnosis of hypertension, we find that, upon receiving hypertension diagnosis, individuals reduce fat intake significantly, and richer individuals reduce more. Our results also indicate that among the rich, hypertension diagnosis is more effective for individuals with lower education.

Does smoking affect schooling? Evidence from teenagers in rural China.

Youth smoking can biologically reduce learning productivity. It can also reduce youths' expected returns to education and lower their motivation to go to school, where smoking is forbidden. Using rich household survey data from rural China, this study investigates the effect of youth smoking on educational outcomes. Youth smoking is clearly an endogenous variable; to obtain consistent estimates of its impact, we use counts of registered alcohol vendors and a food price index as instrumental variables. Since the variable that measures smoking behavior is censored for non-smoking adolescents, we implement a two-step estimation strategy to account for the censored nature of this endogenous regressor. The estimates indicate that smoking one cigarette per day during adolescence can lower students' scores on mathematics tests by about 0.08 standard deviations. However, we find no significant effect of youth smoking on either Chinese test scores or total years of schooling.

Pediatric high-flow, cervical spinal, macro-arteriovenous fistula, treated with the endovascular cotton candy glue injection technique.

CASE REPORT: A 3-year-old boy presented to our hospital with progressive neurological deficits. Spinal magnetic resonance imaging (MRI) revealed a perimedullary macro-arteriovenous fistula (PMAVF) resulting in a large venous pouch within the parenchyma of the lower cervical spinal cord. Transarterial varix embolization of the fistula from the venous side was performed using N-butyl cyanoacrylate with tantalum powder. Postembolization angiography confirmed obliteration of the fistula, and MRI revealed thrombosis and reduction in size of the venous component. The patient's clinical symptoms were reduced dramatically following the intervention, and no neurological complications occurred due to the treatment. The prognosis of spinal PMAVF depends primarily on the presence of medullar signs and symptoms and on time to treatment. The volume of the venous pouch after the intervention was markedly reduced, and complete clinical recovery was obtained. Urgent endovascular intervention, as seen in this case, is considered first-line therapy and aims to decrease the risk of neurological sequela.

Lecithinized superoxide dismutase improves outcomes and attenuates focal cerebral ischemic injury via antiapoptotic mechanisms in rats.

BACKGROUND AND PURPOSE: Recent studies have shown the antiapoptotic neuroprotective effects of lecithinized superoxide dismutase (PC-SOD) in different forms of brain injury. We tested the effects of PC-SOD in focal cerebral ischemia in the rat middle cerebral artery occlusion model (MCAO). METHODS: Adult male Sprague-Dawley rats were treated with PC-SOD (0.3, 1.0, and 3.0 mg/kg) administered intravenously after 90 minutes of occlusion (beginning of reperfusion). Physiological parameters, neurological score, and infarct volume were assessed at 24 and 72 hours in 3 groups of animals: sham-operated (n=18), MCAO treated with vehicle (n=26), and MCAO treated with PC-SOD (n=37). Oxidative stress was evaluated by malondialdehyde assay, and the apoptotic mechanisms were studied by Western blotting. RESULTS: PC-SOD treatment significantly reduced infarct volume and improved neurological scores at different time points compared with the vehicle-treated group. PC-SOD treatment decreased malondialdehyde levels, cytochrome c, and cleaved caspase 3 expression and increased mitochondrial Bcl-2 expression. CONCLUSIONS: Inhibition of oxidative stress with PC-SOD treatment improves outcomes after focal cerebral ischemia. This neuroprotective effect is likely exerted by antiapoptotic mechanisms.

Morphologic changes in neo-intimal proliferation in an experimental aneurysm after coil embolization: effect of factor XIII administration.

We investigated histological changes in aneurysmal orifices after embolization with Guglielmi detachable coils (GDCs) and determined the effects of the wound-healing factor, factor XIII, on promoting intimal proliferation by scanning electron microscopy (SEM). GDC embolization was performed in an experimental model of aneurysm in swine. In the control group (17 aneurysms), the aneurysms were resected immediately after surgery, at 1 and 3 weeks after the procedure. In the factor XIII-administered group (13 aneurysms), the swine received factor XIII postoperatively, and the aneurysms were excised at 1 and 3 weeks. The endothelial cell proliferation changes in the aneurysm orifices in both groups were evaluated by SEM. The histological changes at the orifices began immediately after the procedure, and endothelialization was observed at 1 week. One week after the procedure, the rate of endothelial cell proliferation was significantly higher in the factor XIII group (P<0.05). But no difference was observed at 3 weeks, when endothelialization of the orifices was essentially completed. The process of intimal proliferation after coil embolization was similar to the wound-healing process after vascular intimal injury. Administration of the wound-healing factor, factor XIII, would contribute rapid intimal proliferation and may be effective to facilitate complete obliteration of aneurysms after coil embolization.

De novo dissecting aneurysm in a patient with a ruptured saccular lesion. Case report.

Formation of a new saccular aneurysm after successful treatment of ruptured aneurysm has recently raised significant clinical concerns; however, de novo formation and rupture of a dissecting aneurysm has not been discussed. The authors report on a 42-year-old man who initially sought treatment for a ruptured saccular aneurysm of the right middle cerebral artery, which was successfully eliminated by surgical clipping of the aneurysm neck. Two years later, the patient presented with another subarachnoid hemorrhage and was found to have a dissecting aneurysm of the right vertebral artery, which arose from a previously angiographically documented normal artery. This rare association sheds light on the causes and growth of two distinct types of aneurysms, both clinically and pathologically.