食道アカラシアの治療―内科的治療

Treatment of Esophageal Achalasia: Internal Medication

要旨　食道アカラシアは食道運動機能障害の代表的疾患であるが，その病態生理は不明な点が多い．lower esophageal sphincter（LES）の弛緩不全と食道体部蠕動波の消失による食道の排出障害が主体であり，食物の食道内停滞に基づく諸症状が出現するが，内科的治療としてその原因となる病態を改善させる治療はなく，LESを直接弛緩させる治療が行われている．Ca拮抗薬，亜硝酸薬の投与およびLESの強制拡張術などである．Ca拮抗薬，亜硝酸薬投与で長期間寛解を維持することは困難な例が多く，拡張術を行うことになる．拡張術の有効率は9/11（81.8％）であった．更に最近欧米で行われているbotulinum toxinの内視鏡的局注療法についても述べる．

　Esophageal achalasia is a disorder representative of esophageal motor dysfunction, but its pathophysiology largely remains obscure. An esophageal emptying disorder associated with insufficient relaxation of the lower esophageal sphincter (LES) and elimination of peristaltic waves in the esophageal body is the major abnormality of this disease, manifesting various symptoms associated with food retention in the esophagus. However, there are no internal medications available to deal with the causative pathology, and direct relaxation of LES is the therapy used in the treatment of this disease. The therapy includes administration of a calcium channel blocker or nitrate and mechanical dilatation. Since it is usually difficult to maintain long-term remission with a calcium channel blocker or nitrate, dilatation has to be undertaken in many cases. The efficacy rate of dilatation was 9/11 (81.8%). In addition, we also describe endoscopic local injection therapy with botulinum toxin, which has recently been performed in Western countries.