シートベルト損傷によるMorel–Lavallée lesionの1症例(A case of Morel–Lavallée lesion due to seatbelt injury)

要旨 Morel–Lavallée lesion（以下，MLL）は，高エネルギー外傷後にみられる閉鎖性デグロービング損傷で，血液，リンパ液，壊死性脂肪で満たされた空洞を形成する稀な疾患である。今回，本邦では未だ報告のないシートベルト外傷によるMLLの1例を経験したので報告する。症例は60代の男性。自動車運転中に電柱に衝突し受傷した。来院時，前縦隔に血腫を伴う胸骨骨折，右下腹壁動脈分枝損傷を伴う右鼠径部の皮下血腫，左多発肋骨骨折，右鎖骨骨折を認め，右下腹壁動脈分枝と左内胸動脈分枝に経皮的動脈塞栓術を施行した。右鼠径部の皮下血腫は消退し，第3病日にfollow upの胸腹部CTを施行したが新たな異常所見はなく，リハビリテーションを強化した。第6病日に両鼠径部に新たな皮下血腫が出現し，第7病日のCTでは両鼠径部に液面形成を伴った液体貯留を認めた。MLLと診断し，第8病日に血腫除去・ドレナージ・洗浄を行った。入院経過中に急性胆嚢炎を合併し胆嚢摘出術を施行したが，その後の経過は良好で，第48病日に独歩で自宅退院した。本症例は，シートベルトによる強い剪断応力により両鼠径部にMLLを発症したと考えられた。 ABSTRACT The Morel–Lavallée lesion (MLL) is a rare closed soft–tissue degloving injury commonly associated with high–energy trauma that creates a cavity filled by blood, lymph, and debris. A male driver in his 60s was injured in a motor vehicle crash. He was presented to the emergency department with seat belt injuries that caused a sternal fracture, a right clavicle fracture, left X/XI rib fractures, and a right inguinal subcutaneous hematoma. The right inguinal subcutaneous hematoma was reduced spontaneously, and a body CT on the 3rd day showed no new abnormal findings. However, new subcutaneous hematomas were found in both inguinal regions on the 6th day. Contrast–enhanced CT on the 7th day revealed fluid collections with fluid–fluid level formation in both inguinal regions, and we diagnosed them as MLL. Hematoma removal, drainage, and lavage were performed on the 8th day. He underwent cholecystectomy due to acute cholecystitis that developed during hospitalization. He recovered favorably and was discharged from the hospital on the 48th day. This case demonstrates MLL caused by seat belt shear stress on both inguinal regions after a car accident.