N-butyl-2-cyanoacrylate-Lipiodol-Ethanol（NLE）混和液の特性と臨床

－Balloon-assisted embolization using NLE（b-NLE）の有用性－

抄録

N-butyl-2-cyanoacrylate (NBCA) is a liquid adhesive composed of monomers that polymerize into a solid after contact with anions in the blood. The strong adhesive properties of NBCA can result in adhesion to the catheter and vessel wall, and occlusion or clogging of the catheter, with unpredictable outcomes. A mixture of NBCA with lipiodol and ethanol (NLE) is a new liquid embolic material that is less adhesive than NBCA. The inflammatory change to the vascular wall caused by NLE is milder than that caused by NBCA. NLE forms a plug without adhering to the catheter or balloon. We mainly use NLE (1:4:1, 2:7:1, 3:6:1, or 2:2:1) in the following procedures: balloon-assisted embolization (b-NLE) for visceral aneurysm and arteriovenous malformation (AVM); prophylactic intraoperative AAA sac embolization during endovascular aneurysm repair (EVAR); balloon-occluded retrograde transvenous obliteration (BRTO) for gastric varices; transarterial embolization (TAE) or percutaneous direct sac embolization for endoleak; and preoperative percutaneous transhepatic portal embolization (PTPE), and preoperative TAE to reduce intraoperative bleeding. The optimum ratio of NLE varied according to the size of and flow speed within the target vessels. NLE (141), with a low concentration of NBCA, is suitable for embolization such as BRTO and PTPE, where it is necessary to fill the target vessel without anterograde blood flow under balloon occlusion. Although NLE (141) has the drawback of migration, it can be safely used under flow reduction using a balloon catheter or in combination with metallic coils. NLE (271, 361), with a moderate concentration of NBCA, is suitable for arterial embolization in situations such as endoleak cavities and AVM. NLE (221) with a high concentration of NBCA does not migrate, even after balloon deflation, and is suitable for balloon-assisted embolization of visceral aneurysms (b-NLE).