食道炎の内視鏡診断―逆流性食道炎（NERDを含む）

Endoscopic Diagnosis of Reflux Esophagitis Including Non-erosive Reflux Disease

要旨　逆流性食道炎（RE）の内視鏡分類としてロサンゼルス（LA）分類が一般的に用いられている．欧米から，このLA分類による重症度と逆流症状は相関するとの報告があるが，通常，その関連性は乏しいとされる．筆者らの検討でも，症状を伴わない無症候性REを28.3％に認め，LA分類の重症度別にみても，無症候性と症候性の頻度に差を認めないことが明らかとなった．本邦では，明らかな粘膜傷害を伴わない発赤や白濁所見をminimal changeとしてLA分類に加え，改変版LA分類として汎用されている．しかし，このminimal changeの診断一致率は非常に低く（κ値＝0.033），interobserver variationを認めた．さらに，3例の同一症例での検討でもintraobserver variationを認めた．minimal changeの診断には，画像強調内視鏡観察が有用とされ，今後の展開が期待される．

　The Los Angeles（LA）classification system is most commonly accepted in the endoscopic diagnosis of RE（reflux esophagitis）. Whether grades of the LA classification correlate with the reflux symptom is controversial. In our study, asymptomatic RE, that shows RE without any reflux symptoms, was observed in 28.3％, and there was no significant differences in proportions of grades of the LA classification between asymptomatic and symptomatic RE patients. The LA classification（modified LA system）has been modified to include minimal changes that reveal erythema without sharp demarcation, whitish turbidity, and/or invisibility of vessels due to these findings, and this modified LA system is used widely in Japan. Interobserver agreement was extremely poor（κvalue＝0.033）in the diagnosis of minimal changes of RE. Furthermore, intraobserver variation was seen when evaluating the reproducibility by an analysis of assessments of 3 paired identical RE cases including minimal changes. More recently, it has been reported that image enhanced endoscopy such as narrow band images is useful in the diagnosis of minimal changes, and it is expected to proceed with the newly diagnostic criteria of this classification.