目的 :明确食管扩张时下食管括约肌发生松弛状态下胃食管反流的发生率。方法 :12例健康志愿者在餐前和餐后同时检测食管压力和 pH ,食管扩张是通过快速和缓慢的气体注射诱发。 结果 :引起完全的下食管扩约肌松弛的气体阈值量平均为 (11 0± 1 0 )ml。只有极少的松弛伴有继发蠕动。快速注气下食管括约肌的松弛时间为(13.0± 1.5 )s;慢速注射时食管括约肌的松弛时间是 (16 0± 2 0 )s。由快速阈值量气体注射引起LES松弛并伴有胃食管反流率 ,在餐后为 (2 2± 6 ) % ;缓慢注射时为 (2 3± 10 ) %。对于快速食管扩张 ,单独的下食管括约肌松弛伴随反流的百分比显著高于伴有继发蠕动的下食管括约肌松弛时出现的胃食管反流情况。结论 :(1)胃食管反流可以发生在由食管扩张引起的下食管括约肌松弛期内 ;(2 )食管扩张可以引起不伴随继发蠕动的单纯下食管括约肌松弛 ;(3)单纯下食管括约肌松弛时的胃食管反流发生率显著高于伴有继发蠕动的情况。 OBJECTIVE: To determine the incidence of gastroesophageal reflux in a relaxed esophageal sphincter under esophageal dilation. METHODS: Esophageal pressure and pH were measured in both healthy volunteers before and after meals. Esophageal dilation was induced by rapid and slow gas injections. RESULTS: The mean threshold of gas that caused complete relaxation of the lower esophageal sphincter was (11 0 ± 10) ml. Only a few loose accompanied by secondary peristalsis. The fasting time of esophageal sphincter was (13.0 ± 1.5) s under fast gas injection and the relaxation time of esophageal sphincter was (16 ± 20) s at the time of slow injection. LES relaxation was associated with gastroesophageal reflux with a fast threshold dose of gas injection (22 ± 6)% postprandial and (23 ± 10)% for slow injection. For rapid esophageal dilation, the percentage of lower esophageal sphincter relaxation alone with reflux was significantly higher than that of the lower esophageal sphincter with secondary peristalsis. Conclusions: (1) Gastroesophageal reflux may occur during the lower esophageal sphincter relaxation caused by esophageal dilatation; (2) Esophageal dilatation can cause simple lower esophageal sphincter relaxation without secondary peristalsis; (3) Lower esophageal sphincter The incidence of gastroesophageal reflux during relaxation was significantly higher than with secondary peristalsis.