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Neuroendovascular catheterization using fluoroscopy poses the problem to operators and staffs of cumulative radiation exposure. To solve this problem, we are developing a remote-controlled master-slave robot. Because a wire-like elongated treatment device is inserted into a blood vessel using a catheter, the robot requires a sensor to detect the insertion force of the wire. The proposed sensor is integrated into a robot installed in an X-ray fluoroscopy room that is remotely controlled from another room. The features of this sensor include measurement of the insertion force with sufficient accuracy, simple wire attachment, and an inexpensive disposable sensor head, rendering it very suitable for practical application. In this paper, we report on these features, as well as the results of a practical test of the sensor using a cerebrovascular model. [ABSTRACT FROM AUTHOR]

Complete and secure occlusion of the entire aneurysmal neck remains a problem despite major advances in the treatment of intracranial aneurysms using endovascular coil embolization. Here, we present our initial clinical experience using a novel strategy for endovascular coil embolization involving a microcatheter tip, known as the "Γ (gamma) tip method," and compare the in vitro results of this technique with those of conventional straight microcatheters. The microcatheters were bent at a right angle starting 1–2 mm from the length of the tip using a catheter-shaping mandrel and a hot air gun. The tiny right-angled tip is the "Γ tip." In aneurysm models, we assessed the efficacy of shaping during coil deployment. The Γ-tipped microcatheters demonstrated better movement and oscillation during insertion of the coil into the aneurysm compared with the straight-tipped catheters. Moreover, the Γ-tipped microcatheter provided less coil protrusion into the parent artery and less microcatheter kickback compared with the straight tip. With the Γ-tipped microcatheter, even if the first coil loop migrated into the parent artery, its subsequent dynamic movement routed it back into the aneurysm. The Γ tip method enabled smooth movement of the microcatheter into the aneurysm, demonstrating the safety and security of coil insertion using the Γ tip compared with the conventional straight tip. [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]

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: 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]

Persistent primitive trigeminal artery (PPTA) is the most common type of fetal carotid-basilar persisting communication in adulthood; however, carotid-cavernous fistulas (CCFs) associated with PPTA are rare. An 84-year-old woman presented with traumatic CCF associated with PPTA manifesting as vascular bruit. Transarterial embolization was performed. Although a detachable coil was deployed at the fistula point, it was easy to migrate into the cavernous sinus because of the high-flow shunt. Therefore, a stent was deployed in the PPTA, and the inner lumen of the stent with a focus on the fistula point was occluded by using coils. Subsequently, the CCF completely disappeared. In-stent coil embolization was effective and reasonable for the high-flow CCF associated with the PPTA. This method reduced the number of coils required and operating time. However, careful preservation of perforators is needed. [ABSTRACT FROM AUTHOR]