細径（5mm）超音波凝固切開装置の先端部cavitationが要因と思われる内視鏡下拡大胸腺摘出時の左腕頭静脈損傷の1例

A Left Brachiocephalic Vein Injury attributed to a Cavitation caused by the Tip of an Ultrasonically Activated Device during Endoscopic Extended Thymectomy

　細径超音波凝固切開装置（Harmonic Scalpel J5）の先端部cavitationが要因と思われる左腕頭静脈損傷の1例を経験した．患者は16歳の女性．重症筋無力症にて胸骨挙上式内視鏡下拡大胸腺摘出術を施行した．術後8時間，突然ドレーンから出血を認めたため緊急胸骨縦切開を行った．左腕頭静脈中央尾側部に3mm大の穿孔部を認め，これを縫合閉鎖した．術中ビデオの詳細な解析より超音波凝固切開装置先端部のcavitationが血管損傷の直接要因と考えられた．内視鏡下外科手術で汎用される超音波凝固切開装置は，その先端部が発生するcavitationの障害を熟知した上で適正に使用することが必要である．

We encountered a patient with left brachiocephalic vein injury probably due to the cavitation caused by the tip of an ultrasonically activated device (Harmonic Scalpel J5) that measured 5mm in diameter. The clinical course is reported. The patient was a 16-year-old female with myasthenia gravis who underwent endoscopic extended thymectomy. Eight hours after the operation, sudden hemorrhage was observed from the drain and emergency median full sternotomy was performed. A perforation measuring 3mm in diameter was observed at the center of the caudal part of the left brachiocephalic vein.