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Objective In neuroendovascular treatment, there are many opportunities to guide multiple catheters into the intracranial blood vessels. We report the relationship between two microcatheters according to the guiding order with experimental in vitro studies. Materials and Methods We hypothesize that in a bent blood vessel such as a paraclinoid region of the internal carotid artery, the catheter that was first guided tended to pass through the inside, and the catheter that was guided later tended to pass through the outside. The in vitro verification was performed using a microcatheter and a balloon catheter in a silicone vascular aneurysmal model. Results As a result, it was found that the two catheters were arranged according to our hypothesis. This finding was also observed during the actual operation of balloon-assisted coil embolization. Conclusion The positional relationship between the two catheters according to the navigation order is very important, in particular during balloon-assisted coiling and stent-assisted coiling via a jailed microcatheter. [ABSTRACT FROM AUTHOR]

Objective We noticed that the X-ray absorption value of the tip of each microcatheter used for aneurysm treatment varied from product to product. We hypothesized that the differences were caused by variations in the metal's density braid, which could be related to the ability of the tip to retain its shape. Methods The X-ray absorption value of each microcatheter tip was measured. Next, heat forming was performed using a shaping mandrel at 6 mm and 90 degrees to determine whether there was a correlation between the X-ray absorption value and the forming angle. Next, the optimal mandrel angle for forming each microcatheter at 90 degrees was investigated. We also examined the shape retention after 20 times wire insertions into each microcatheter. Conclusion It was found that the higher the X-ray absorption value, the harder it was for the microcatheter to be formed. The mandrel angle required to form 90 degrees was determined by the X-ray absorption value. The higher the X-ray absorption value, the higher the shape retention of the tip shape. The heat formation and shape-retention conditions of the microcatheter tip were correlated with the X-ray absorption value of the metal braid. Even for unknown microcatheters, the optimum shaping conditions can be inferred from the X-ray absorption value. [ABSTRACT FROM AUTHOR]

Mechanical thrombectomy has been widely used for the treatment of acute ischemic stroke. During this procedure, operators must navigate the microcatheter with a microguidewire (MGW) into vessels that cannot be visualized on fluoroscopy as rapidly as possible. In this study, we developed a modified pigtail-shaped MGW (MPMGW) for security and controllability. Moreover, the efficacy of the MPMGW for the treatment of acute ischemic stroke was assessed. The MPMGW was designed using 0.014 MGW. Because we created four MPMGWs during a clinical evaluation before the launch in the market, these wires were used in four consecutive patients with acute ischemic stroke in the single institution. The occluded arteries were the basilar artery (n = 1), middle cerebral arteries (M1 and M2, n = 2), and internal carotid artery (n = 1). All four procedures were conducted without any complications. The procedures included navigating the MGW and passing it through the clot. Complete recanalization was achieved in all cases. The average time between femoral artery puncture and recanalization was 15 min. The use of the preshaped MPMGW in acute thrombectomy was effective in terms of both security of procedure and reduction in recanalization time. [ABSTRACT FROM AUTHOR]

Background: When inserting coils under stent deployment, a jailed microcatheter technique is typically applied as a first line approach. However, the trans cell approach might be required to achieve satisfactory complete occlusion. The trans cell approach occasionally ends in failure because the catheter cannot safely follow a proceeding guidewire into the aneurysm. Here, we report the new wireless trans cell approach (WTA), which allows feasible and safe catheter navigation through the stent strut into the aneurysm, without a proceeding guidewire. Methods: A straight tip microcatheter was used, and the tip was shaped as a very small bend of approximately 45°. The side aspect of the catheter tip exhibited a right angled edge, while the front aspect showed a round curve in the advancing direction. We compared the 45° microcatheter with a straight tip microcatheter using a silicon vascular model and then applied the WTA in a case of an unruptured basilar apex aneurysm. Results: Catheter navigation through the stent strut was smoother with the WTA than the conventional wire assisted approach. Our case of a basilar apex aneurysm was successfully treated with the dual catheter technique, which involved a jailed catheter and navigation using the WTA. After stent deployment from the right posterior cerebral artery to the basilar artery through the 45° microcatheter, the WTA was applied using the same catheter. No stress was detected during catheter navigation through the stent strut into the aneurysm. Conclusions: The WTA is associated with smoother catheter navigation compared with the conventional wire assisted approach in cases of a terminal type aneurysm. [ABSTRACT FROM AUTHOR]

A 75-year-old man presented with right-sided hemiplegia and was diagnosed with a left middle cerebral artery occlusion. He underwent endovascular thrombectomy, and a bulge was found. A modified pigtail-shaped microguidewire (MPMGW) proved useful for diagnosis because it allowed differentiation between the occluded artery and a saccular aneurysm as the etiology. When a clot was partially retrieved, a previously unidentified vessel dilatation appeared. The dilatation origin was unclear and could have resulted from either the occluded artery or an unruptured saccular aneurysm. We tried to navigate the MPMGW into the bulging area. The patient showed unusual body movement attributed to pain and the dilatation was diagnosed as an aneurysm. Subsequent 3-dimensional angiography revealed a recanalized artery and the aneurysm. With no subarachnoid hemorrhage or extravasation of the contrast medium. The hemiplegia dramatically improved. An MPMGW may be useful in acute thrombectomy where the target vessel cannot be visualized during the procedure. [ABSTRACT FROM AUTHOR]

Objectives: Various endovascular approaches have been reported for patients with intracranial aneurysms. However, the safety of navigating a microcatheter into the aneurysm remains debatable. In this study, we evaluated a novel method "dunk shot technique," in which a proximal balloon and a local balloon are used for navigation of a microcatheter into an aneurysm under challenging situations. Materials and Methods: We have reported two cases of unruptured internal carotid artery–superior hypothalamic artery aneurysm. An 8-F balloon-attached catheter was used as the guiding catheter. A local balloon catheter for neck remodeling and a microcatheter for coil insertion were navigated around the aneurysmal neck region. When it seemed difficult to navigate a microcatheter into an aneurysm, both the guiding balloon and a local balloon catheter were used for assistance. After inflation of the guiding balloon, the local balloon was inflated partially to negotiate the tip of the microcatheter. Results: The uncontrollable tip of the microcatheter could be intentionally moved by the local balloon. Conclusions: We evaluated the effectiveness of the balloon-assisted technique for the navigation of a microcatheter in cases with challenging anatomy. A little bit of direct effect to the tip of the microcatheter by a local balloon could produce effective outcomes under the proximal flow arrest. [ABSTRACT FROM AUTHOR]

Background: Stent clot retrievers can be used to perform mechanical thrombectomies to treat cases of acute major arterial occlusion. This approach is associated with faster recanalization and better outcomes than internal treatments. The function of the stent retrievers is based on a technique known as confront clot scrambling method (CCSM), which usually involves the insertion of two stent retrievers (one from each side) and the simultaneous withdrawal of the retrievers with an equal force. It was determined that a stent used to remove the sham clot possessed a stronger ability for clot retrieval. However, this method involves inherent manipulation bias, and the results may vary due to operator-specific factors. Thus, this approach can be difficult to teach, especially to beginners. Materials and Methods: We evaluated the accuracy of using an equitable automatic withdrawal machine for the CCSM on a model of a sham clot in the middle of a polyvinyl chloride tube. Results: This tool is expected to facilitate thorough and repeated training that is needed to learn the fine maneuvers against invisible vessels associated with actual endovascular clot retrieval, particularly for beginners. [ABSTRACT FROM AUTHOR]

Background: When a shaping mandrel is inserted into the tip of a preshaped microcatheter, the existing curve becomes uncertain because the tip is straightened by the inner mandrel. Therefore, we developed a way to perform microcatheter shaping by means of an external cast, which we named "microcatheter shaping cast." Techniques: A shaping mandrel attached to a microcatheter was used and coiled 4–5 times around a metallic introducer, which was attached using a microguidewire. Then, a stent-like handmade cast was prepared. After the microcatheter tip was inserted into the cast, it was manually bent according to the aneurysmal shape and size. The tip and cast were heated with a hot air gun. We evaluated the relationship between degrees of bending and heating time to achieve appropriate right-angled shaping memory. Conclusions: The presented microcatheter shaping method should be more useful than conventional internal shaping, especially in cases that require an additional microcatheter shaping or reshaping during aneurysmal coil embolization. [ABSTRACT FROM AUTHOR]

The combination of a flow reversal with two balloons and a filter protection device is one of the safest methods that can be used during carotid artery stenting (CAS). Although major adverse events did not occur under restrict protection, we experienced a case of in-filter thrombus during the procedure. A 68-year-old male presented with temporary right hemiparesis. The radiological examinations revealed 95% stenosis on the origin of the left internal carotid artery (ICA). The patient underwent left CAS of wherein a proximal common carotid artery balloon, an external carotid artery balloon, and a distal ICA filter, with continuous flow reversal to the femoral vein, were used. Although the reversal circulation was established, a massive newly developing thrombus was found in the proximal side of the filter. After an additional systemic heparinization, the thrombus disappeared. The procedure was performed without any complications. Physicians should be aware of the risk of developing intraprocedural thrombosis in a filter protection device. Because the filter protection device is designed for the antegrade flow, it may promote the development of thrombus against the retrograde flow. Thus, the filter protection device should be retrieved first under the flow reversal circumstance to avoid the distal migration of a clot around the filter device. [ABSTRACT FROM AUTHOR]