| 特集名 | GERD診療2018―現状と課題 | |
|---|---|---|
| 題名 | GERDの病態 | |
| 発刊年月 | 2018年 03月 | |
| 著者 | 小泉 英里子 | 日本医科大学消化器内科学 |
| 著者 | 岩切 勝彦 | 日本医科大学消化器内科学 |
| 【 要旨 】 | 逆流性食道炎（RE）は食道内の過剰な胃酸曝露によって発症する．過剰な食道内胃酸曝露には，①胃酸逆流の頻度，②胃酸逆流後の胃酸上昇パターン，③胃酸逆流後の胃酸排出パターンが関連している．胃酸逆流のおもなメカニズムは一過性LES弛緩であり，一過性LES弛緩頻度は健常者とGERD患者間に差はないが，一過性LES弛緩時の酸逆流の合併率はGERD患者で有意に増加している．この一過性LES弛緩時の酸逆流の合併率の違いの原因として，近年acid pocketにも注目が集まっている． 一方，NERDの約60～70％は酸逆流による症状であるが，残りはほかに原因がある．その他の症状の原因としては食道知覚過敏の存在による酸以外の逆流，食道運動障害，好酸球性食道炎，機能性胸やけなどが挙げられ，鑑別が重要となる．NERDの逆流は口側に逆流するほど症状が出やすく，また二次蠕動波の出現率が低下していることが特徴である． 標準量のPPIを投与するも効果が不十分である場合には，GERD診療ガイドラインでは，症状との関連を評価するために食道インピーダンス・pH検査，食道内圧検査を行うことが提案されている． |
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| Theme | GERD in Clinical Practice 2018 -- Current Status and Issues | |
|---|---|---|
| Title | Pathophysiology of Gastroesophageal Reflux Disease (GERD) | |
| Author | Eriko Koizumi | Department of Gastroenterology, Nippon Medical School, Graduate School of Medicine |
| Author | Katsuhiko Iwakiri | Department of Gastroenterology, Nippon Medical School, Graduate School of Medicine |
| [ Summary ] | Gastroesophageal reflux disease (GERD) can be categorized into 2 types, each with a distinct pathology : reflux esophagitis (RE) which is associated with esophageal mucosal breaks and non‒erosive reflux disease (NERD) without any esophageal mucosal breaks. The cause of RE is attributable to excessive esophageal acid exposure. Acid reflux and esophageal acid clearance after acid reflux are important factors related to excessive esophageal acid exposure. The primary mechanism associated with acid reflux is transient lower esophageal sphincter relaxation (TLESR), which refers to LES relaxation that is not associated with swallowing. It must be noted that acid reflux caused secondary to a low LES pressure is a rare condition. The frequency of TLESR during the postprandial period does not significantly differ between healthy individuals and patients with GERD ; however, the incidence of acid reflux episodes occurring during TLESR is significantly higher in patients with GERD. The layer of acid that appears above the layer of food in the stomach immediately below the esophagogastric junction (acid pocket) has been gaining increasing attention as a possible factor that determines the difference between the groups in terms of acid reflux during TLESR. Regarding NERD it must be noted that approximately 60‒70 % of reflux symptoms are attributable to acid reflux and the remaining to non‒acid reflux secondary to esophageal hypersensitivity, esophageal motility disorders, eosinophilic esophagitis, and functional heartburn, among other such conditions. A study analyzing esophageal motor function demonstrated that patients with NERD showed defective triggering of secondary peristalsis compared to that observed in healthy individuals. Persistence of reflux symptoms after the completion of standard‒dose proton pump inhibitor (PPI) therapy, warrants evaluation of the pathophysiology associated with this condition using esophageal multi‒channel impedance testing and pH monitoring and/or esophageal manometery to determine the relationship between symptoms and esophageal pathophysiology. | |