末期大腸癌患者の僧帽弁位人工弁感染に対し再弁置換を行った1例

Redo Mitral Valve Replacement for Prosthetic Valve Endocarditis in a Patient with End Stage Colon Cancer：Report of a Case

はじめに　進行癌患者が開心術を要することはきわめてまれである．われわれは，多発肝転移を伴う大腸癌切除術後患者に発症した感染性心内膜炎に対し僧帽弁置換術を行い，術後1年で人工弁感染をきたした症例を経験したので報告する．

Prosthetic valve endocarditis （PVE） is rare but devastating. A 69-year old man admitted for active endocarditis caused by Streptococcus pasteurianus. Antibiotic therapy was started, but the patient developed bowel obstruction owing to cancer with multiple liver metastases, and underwent transverse colectomy. Following colectomy, antibiotic agent was given continued for 4 weeks after and mitral valve replacement （MVR） using a bioprosthesis was performed. Oral antibiotic therapy was continued for six months after MVR to avoid infection recurrence. One year after MVR, the size of multiple liver metastases increased despite oral anticancer drugs administration. A totally implantable central venous access port （CV port） was placed and intravenous chemotherapy was started for progressive metastatic colorectal cancer. But the CV port was removed due to device infection caused by multiple drug resistant Staphyrococcus lugdunensis one month later, but the patient developed prosthetic valve endocarditits （PVE） due to the same bacterium, that caused valve stenosis. Redo MVR was indicated because of progressive dyspnea and uncontrollable fever. The patient was discharged one month after redo MVR, but suffered carcinomatous peritonitis, and eventually died eight months post-discharge. Chemotherapy needs caution because of potential risk of PVE in patients with prosthetic valves, especially for those with a history of infectious endocarditis.