コイルの選択と挿入法および離脱困難時の対応は？

Coil Selection, Handling and Troubleshooting in Detachment Failure

Point

・虎の門病院における未破裂脳動脈瘤症例の後方視的な研究より，1stコイルが留置コイルの体積の1/3以上を占めると，再発・再治療が少なくなることが明らかとなった．

・コイルを留置しながらカテーテルの位置を調整するためには，機器の把持の仕方を工夫する必要がある（Fig. 1）．

・離脱不良とその対応には機器の添付文書を参照する．離脱位置の確認や電源部（パワーサプライ）の交換などでも離脱できない場合，推奨されないが，ワイヤーの回転によるねじ切りやワニグチクリップによる電気回路の再建などの手段もある．

　The first coil should be as thick, long, and large as possible. A retrospective study at the Toranomon Hospital revealed that if the volume of the first coil is 1/3rd or more of the total coil volume, there are less chances of retreatment. Thus, a thick and long first coil contributes to stable long-term anatomical results. The length of the first coil should be approximately 8% of the volume of the aneurysm. After the placement of the first coil, a smaller and shorter coil should be placed sufficiently close to it to complete the procedure. The goal is to achieve prevention of acute re-rupture in ruptured acute aneurysms and life-long prevention of rupture in unruptured asymptomatic aneurysms. If the coil does not detach, check the position of the detachment point, and replace the power supply. In addition, refer to the direction for use of the device for prevention of coil disconnection failure and countermeasures. Although it is not a recommended method, a method of rotating the delivery wire at the detached position to thread the coil and a method of reconstructing the electric circuit with a crocodile clip has been reported.