胸腔ドレーンによる高圧吸引がvacuum assisted closure(VAC)療法的効果を呈した膿気胸の1例

A Case of Pyopneumothorax Treated Successfully with Continuous Strong Suction Drainage Effected Like Vacuum-assisted Closure

要旨　症例は63歳，男性．肺癌に対し右肺葉切除の既往あり．慢性間質性肺炎の診断でプレドニン20mg/日が投与されていた．肝癌が発見されたが治療開始前に左上葉肺炎で入院となった．感染性肺囊胞が肺炎部に出現，急速に拡大し破裂した．通常の持続吸引を行ったが，多剤耐性緑膿菌による膿気胸に進展した．瘻孔閉鎖術を試みたが瘻孔は深く成功しなかった．難治性膿気胸に対する永久胸壁開窓術を予定し，肺の胸壁癒着を目的に術後から50mmHgの高吸引圧で持続吸引を行った．53日目にair leakが消失し，抗生剤を早期に打ち切っていたにもかかわらず細菌培養も陰性化した．膿胸に対するVAC療法の有効性を認めた報告がいくつかなされているが，胸腔ドレーンを高陰圧にすることでVAC療法と同様の効果が得られたと考えられた．症例は肝癌で死亡するまでの約1年間，気胸，膿胸ともに再発することなく自立的日常生活を送ることができた．

　There are several reports regarding efficacy of vacuum-assisted closure therapy for pyothorax. We report a case that high pressure vacuum from drainage tubes might be effective for pyopneumothorax. The patient was a 63-year-old man with a history of right lower lobectomy for lung cancer and chronic interstitial pneumonia maintained with 20mg/day of prednisolone. He also had liver cancer resulting from hepatitis B virus-related liver cirrhosis.

　The patient was admitted to our hospital for left upper lobe pneumonia with a new bulla in the infected lesion. He subsequently developed a tension pneumothorax when the infected bulla ruptured. Despite intensive care, the infection and air leak did not resolve. Fluid culture yielded pure growth of multidrug-resistant Pseudomonas aeruginosa.

　Debridement and decortication of the empyema cavity, along with drainage of the abscess and air leak, were performed on the 69th day after the rupture. We administered continuous suction force of-50mm Hg beginning on the day of the surgical procedure. On the 52nd day following the procedure, the air leak spontaneously resolved. Bacterial colonization of the pleural fluid was not detected. The patient was discharged without an open window thoracostomy.

　He lived about one year without recurrence of pneumothorax or pyothoraxtill his death for cancer.