A novel approach involving a microcatheter tip during aneurysmal coil embolization: The Γ (gamma) tip method

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.